bims-rimeca 2023-12-10 papers

bims-rimeca

Biomed News

on RNA methylation in cancer

Issue of 2023–12–10
twenty-six papers selected by
Sk Ramiz Islam, Saha Institute of Nuclear Physics

KIAA1429 facilitates progression of hepatocellular carcinoma by modulating m6A levels in HPN.
RNA N6-methyladenosine-modified-binding protein YTHDF1 promotes prostate cancer progression by regulating androgen function-related gene TRIM68.
Autophagy activation is required for N6-methyladenosine modification to regulate ferroptosis in hepatocellular carcinoma.
Key m6A regulators mediated methylation modification pattern and immune infiltration characterization in hepatic ischemia-reperfusion injury.
m6A modification patterns are associated with copy number burden and tumor immune landscape in thyroid cancer.
Coilin mediates m6A RNA methylation through phosphorylation of METTL3.
METTL3 regulates FAM83D m6A modification to accelerate tumorigenesis of triple-negative breast cancer via the Wnt/β-catenin pathway.
GATA6-AS1 suppresses epithelial-mesenchymal transition of pancreatic cancer under hypoxia through regulating SNAI1 mRNA stability.
Systematic assessment of transcriptomic and metabolic reprogramming by blue light exposure coupled with aging.
NSUN2-mediated m5C modification of HBV RNA positively regulates HBV replication.
Epigenetically upregulated NSUN2 confers ferroptosis resistance in endometrial cancer via m5C modification of SLC7A11 mRNA.
Isothermal Amplification-Based Detection of Single-Base RNA N6-Methyladenosine.
Deletion of Mettl3 in mesenchymal stem cells promotes acute myeloid leukemia resistance to chemotherapy.
METTL3 alters capping enzyme expression and its activity on ribosomal proteins.
METTL14 knockdown inhibits the pyroptosis in the sepsis-induced acute lung injury through regulating the m6A modification of NLRP3.
Exosome-shuttled FTO from BM-MSCs contributes to cancer malignancy and chemoresistance in acute myeloid leukemia by inducing m6A-demethylation: A nano-based investigation.
IGF2BP3-mediated regulation of GLS and GLUD1 gene expression promotes treg-induced immune escape in human cervical cancer.
ALKBH5 protects against stroke by reducing endoplasmic reticulum stress-dependent inflammation injury via the STAT5/PERK/EIF2α/CHOP signaling pathway in an m6A-YTHDF1-dependent manner.
Fentanyl Promoted the Growth of Placenta Trophoblast Cells through Regulating the METTL14 Mediated CCL5 Levels.
TRIM11 regulated by m6A modification promotes the progression of cervical cancer by PHLPP1 ubiquitination.
M6A reader YTHDF1 promotes malignant progression of laryngeal squamous carcinoma through activating the EMT pathway by EIF4A3.
Loss of MTA2-mediated downregulation of PTK7 inhibits hepatocellular carcinoma metastasis progression by modulating the FAK-MMP7 axis.
Silencing of m6A methyltransferase KIAA1429 suppresses the progression of non-small cell lung cancer by promoting the p53 signaling pathway and ferroptosis.
FOXO3a-regulated arginine metabolic plasticity adaptively promotes esophageal cancer proliferation and metastasis.
ABHD12 contributes to tumorigenesis and sorafenib resistance by preventing ferroptosis in hepatocellular carcinoma.
Circular RNA circEYA3 promotes the radiation resistance of hepatocellular carcinoma via the IGF2BP2/DTX3L axis.

Heliyon. 2023 Nov;9(11): e22084

KIAA1429 facilitates progression of hepatocellular carcinoma by modulating m6A levels in HPN.

Yu Meng, Wenwen Yang, Jinchao Li, Wei Chai.

   Background: Most N6-methyladenosine (m6A)-associated modulatory proteins are involved in the pathogenesis of various cancers. The roles of m6A-related genes in liver hepatocellular carcinoma (LIHC) and the associated mechanisms remain unknown.
Methods: GEO and GEPIA2 databases were used to identify the m6A modification-related genes which were differentially expressed in LIHC and adjacent non-tumor tissues, and quantitative PCR was used to evaluate the expression of KIAA1429, a major m6A methyltransferase, in LIHC cells. The effect of KIAA1429 on the malignant phenotypes of LIHC cells was evaluated in vitro. The UALCAN, GEPIA, and GEO databases and western blotting assays were used to identify the target genes of KIAA1429.
Results: KIAA1429 expression was markedly elevated in LIHC tissues, and patients with LIHC who had high KIAA1429 expression had a worse prognosis than those who had low expression. KIAA1429 silencing attenuated LIHC metastasis and proliferation. KIAA142 regulates m6A levels in HPN to intensify LIHC progression.
Conclusion: Our study suggests a KIAA1429-HPN modulatory model based on m6A modifications, that offers insights into the occurrence and development of LIHC.

Keywords:  HPN; Hepatocellular carcinoma; KIAA1429; Migration; m6A methylation

DOI:  https://doi.org/10.1016/j.heliyon.2023.e22084
Eur J Med Res. 2023 Dec 02. 28(1): 552

RNA N6-methyladenosine-modified-binding protein YTHDF1 promotes prostate cancer progression by regulating androgen function-related gene TRIM68.

Qihong Nie, Xiaoyuan Wu, Yongming Huang, Tao Guo, Jin Kuang, Chuance Du.

   PURPOSE: There is no report about the direct relationship between m6A modification and androgen receptor (AR)-related genes in prostate cancer (PC). We aimed to study the mechanisms of m6A methylation in regulating the pathogenesis of PC from the perspective of AR-related genes.
METHODS: qRT-PCR was applied to detect the expression of m6A-related genes in PC cell with or without AR inhibitor. The effects of YTHDF1 knockdown on PC cell viability, apoptosis, migration and invasion were investigated using flow cytometry, wound healing and transwell assays, respectively. The mechanism of YTHDF1 action was investigated using m6A RNA immunoprecipitation (MeRIP) sequencing. The biological functions of YTHDF1 were also explored through in vivo experiments.
RESULTS: YTHDF1 was significantly down-regulated in AR inhibitor group. YTHDF1 knockdown significantly decreased AR level, viability and m6A methylation level of PC cells. TRIM68 was identified as a direct target of YTHDF1. Both YTHDF1 and TRIM68 knockdown increased apoptosis, and decreased cell viability, migration, and invasion of PC cells, while TRIM68 overexpression reversed the effects of YTHDF1 knockdown on PC cells. In addition, knockdown of YTHDF1 or TRIM68 significantly decreased the m6A methylation level, and mRNA and protein levels of YTHDF1, TRIM68 and AR in PC cells, while TRIM68 overexpression increased the expression levels above. Furthermore, subcutaneous xenografts of nude mice also revealed that TRIM68 could reverse the effects of YTHDF1 knockdown in PC in vivo.
CONCLUSION: This study suggested the key role of YTHDF1-mediated m6A modification in PC progression by regulating androgen function-related gene TRIM68 in PC.

Keywords:  Androgen receptor; N6-methyladenosine; Prostate cancer; TRIM68; YTHDF1

DOI:  https://doi.org/10.1186/s40001-023-01533-5
Redox Biol. 2023 Dec 01. pii: S2213-2317(23)00372-5. [Epub ahead of print]69 102971

Autophagy activation is required for N6-methyladenosine modification to regulate ferroptosis in hepatocellular carcinoma.

Yujia Li, Mei Guo, Yangling Qiu, Mengran Li, Yang Wu, Min Shen, Yingqian Wang, Feng Zhang, Jiangjuan Shao, Xuefen Xu, Zili Zhang, Shizhong Zheng.

   BACKGROUND & AIMS: Although ferroptosis holds promise as a new strategy for treating hepatocellular carcinoma (HCC), there are several obstacles that need to be overcome. One major challenge is the lack of understanding about the mechanisms underlying ferroptosis. Additionally, while the m6A modification has been shown to regulate various forms of cell death, its role in regulating ferroptosis in HCC has been largely overlooked. Bridging this knowledge gap, our study aimed to elucidate the regulatory influence of m6A modification on HCC ferroptosis.
MATERIALS: Dot blot and EpiQuik m6A RNA Methylation Quantitative kit detected changes in overall m6A modification level during ferroptosis in HCC. MeRIP-qPCR and RIP-qPCR identified that the m6A modification of ATG5 mRNA was significant changed. BALB/c nude mice were used to construct xenograft tumor models to verify the phenotypes upon YTHDC2 silencing. In addition, patient-derived organoid models were used to demonstrate that induction of ferroptosis was an effective strategy against HCC.
RESULTS: Our study has shown that inducing ferroptosis is a promising strategy for combatting HCC. Specifically, we have found a significant correlation between ferroptosis and high levels of m6A modification in HCC. Notably, we discovered that the elevation of ATG5 mRNA m6A modification mediated by WTAP is dependent on the reading protein YTHDC2. Importantly, inhibition of either WTAP or YTHDC2 effectively prevented ferroptosis and suppressed HCC development in both in vitro and in vivo models.
CONCLUSION: Our study revealed that WTAP upregulates ATG5 expression post-transcriptionally in an m6A-YTHDC2-dependent manner, thereby promoting the translation of ATG5 mRNA during ferroptosis in HCC. These findings have significant implications for the development of innovative and effective therapeutic approaches for HCC treatment.

Keywords:  Autophagy; Ferroptosis; Hepatocellular carcinoma; Translation; m(6)A

DOI:  https://doi.org/10.1016/j.redox.2023.102971
BMC Med Genomics. 2023 Dec 04. 16(1): 314

Key m6A regulators mediated methylation modification pattern and immune infiltration characterization in hepatic ischemia-reperfusion injury.

Yixi Zhang, Can Qi, Yiwen Guo, Xuefeng Li, Zebin Zhu.

   BACKGROUND: N6-methyladenosine (m6A) mRNA modification plays a critical role in various human biological processes. However, there has been no study reported to elucidate its role in hepatic ischemia-reperfusion injury (IRI). This study was aimed to explore the expression pattern together with the potential functions of m6A regulators in hepatic IRI.
METHODS: The gene expression data (GSE23649) of m6A regulators in human liver tissue samples before cold perfusion and within 2 h after portal vein perfusion from Gene Expression Omnibus database was analyzed. The candidate m6A regulators were screened using random forest (RF) model to predict the risk of hepatic IRI. The evaluation of infiltrating abundance of 23 immune cells was performed using single sample gene set enrichment analysis. Besides, quantitative real time polymerase chain reaction (qRT-PCR) assay was carried out to validate the expression of key m6A regulators in mouse hepatic IRI model.
RESULTS: The expressions of WTAP, CBLL1, RBM15, and YTHDC1 were found to be increased in liver tissues 2 h after portal vein perfusion; in contrast, the expressions of LRPPRC, FTO, METTL3, and ALKBH5 were decreased. Based on RF model, we identified eight m6A methylation regulators for the prediction of the risk of hepatic IRI. Besides, a nomogram was built to predict the probability of hepatic IRI. In addition, the levels of WTAP, ALKBH5, CBLL1, FTO, RBM15B, LRPPRC and YTHDC1 were correlated with the immune infiltration of activated CD4 T cell, activated dendritic cell (DC), immature DC, mast cell, neutrophil, plasmacytoid DC, T helper (Th) cell (type 1, 2, and 17), gamma delta T cell, T follicular helper (Tfh) cell, myeloid-derived suppressor cell (MDSC), macrophage, natural killer cell, and regulatory Th cell. Among mouse hepatic IRI model, the mRNA level of CBLL1 and YTHDC1 was increased with statistical significance; however, the mRNA level of FTO and METTL3 was decreased among post-reperfusion liver samples compared with those in pre-reperfusion samples with statistical significance.
CONCLUSIONS: The m6A regulators exerted a pivotal impact on hepatic IRI. The m6A patterns that found in this study might provide novel targets and strategies for the alleviation/treatment of hepatic IRI in the future.

Keywords:  Hepatic ischemia-reperfusion injury; METTL3; YTHDC1; m6A methylation regulators

DOI:  https://doi.org/10.1186/s12920-023-01751-0
BMC Endocr Disord. 2023 Dec 06. 23(1): 271

m6A modification patterns are associated with copy number burden and tumor immune landscape in thyroid cancer.

Liangliang Cai, Tingting Liu, Hujia Hua, Xingyu Jiang, Li Qian.

   BACKGROUND: The association involving N6-methyladenosine (m6A) modification, molecular subtype and specific immune cell group in tumor microenvironment has been the focus of recent studies. The underlying function of m6A modification in thyroid cancer (TC) remains elusive.
METHODS: The m6A modification regulations, molecular character and tumor immune profile of 461 TC patients were explored and then the correlation between them were comprehensively evaluated. The m6Ascore was established using principal component analysis (PCA) to quantify the m6A pattern of individual TC patients. The prognostic significance of the m6Ascore was evaluated by multivariate Cox regression analysis.
RESULTS: Four m6Aclusters (mc1, 2, 3, 4)-characterized by differences in extent of aneuploidy, expression of immunomodulatory genes, mRNA or lncRNA expression pattern and prognosis were identified. T Preliminary validation of m6Ascore was a potential independent prognostic factor of TC involving in mc3. Finally, the prognostic value of the m6Ascore and its association with copy number variation (CNV) and tumor immune microenvironment (TIME) of TC in mc3 were verified.
CONCLUSIONS: The correlation between m6A modification, the copy number burden and tumor immune landscape in TC was demonstrated. A m6Acluster-mc3 with low m6Ascore and high CNV molecular subtype was identified with poor clinical prognosis, low infiltrating immunocyte and weak effector T cell. A three-gene clinical prognosis model for TC based on 4 m6a cluster expression was established. Understanding of TIME is enhanced by comprehensive assessment of m6A patterns in individual TC patients and gives a new insight toward improved immunotherapy strategies for TC cancer patients.

Keywords:  Immunotherapy strategy; N6-methyladenosine; Thyroid cancer; Tumor immune microenvironment

DOI:  https://doi.org/10.1186/s12902-023-01510-3
Biol Open. 2023 Dec 15. pii: bio060116. [Epub ahead of print]12(12):

Coilin mediates m6A RNA methylation through phosphorylation of METTL3.

Douglas M McLaurin, Sara K Tucker, Michael D Hebert.

  MicroRNAs (miRNAs) are a class of noncoding RNAs that regulate gene expression. An important step in miRNA biogenesis occurs when primary miRNAs are bound and cleaved by the microprocessor to generate precursor miRNAs. Regulation at this step is essential and one such regulator includes m6A RNA methylation, an RNA modification found on primary miRNAs that is installed by METTL3 and bound by hnRNPA2B1. Our lab has recently discovered that the Cajal body marker protein coilin also participates in miRNA biogenesis and hypothesized that coilin may be influencing miRNA biogenesis through m6A RNA methylation. Here we report that coilin suppression reduces m6A on primary Let7a and miR-21. We also found that coilin suppression reduced the protein expression of hnRNPA2B1 and METTL3. We observed an interaction between coilin and ectopically expressed METTL3 and found that coilin suppression reduced the nucleoplasmic portion of METTL3 and blunted ectopic METTL3 phosphorylation. Finally, coilin suppression disrupted the greater METTL3 complex with cofactors METTL14 and WTAP. Collectively, our work has uncovered a role for coilin in mediating m6A RNA methylation and provides an avenue by which coilin participates in miRNA biogenesis.

Keywords:  Cajal body; Coilin; METTL3; Methylation; MicroRNA

DOI:  https://doi.org/10.1242/bio.060116
Toxicol In Vitro. 2023 Dec 01. pii: S0887-2333(23)00195-9. [Epub ahead of print] 105746

METTL3 regulates FAM83D m6A modification to accelerate tumorigenesis of triple-negative breast cancer via the Wnt/β-catenin pathway.

Xiaodong Yu, Yaxun Li, Fanshuang Kong, Qun Xu.

  N6-methyladenosine (m6A) modification, the most abundant methylation modification on eukaryotic mRNAs, was implicated in the tumourigenesis. This study aimed to explore the role of methyltransferase like 3 (METTL3) in triple-negative breast cancer progression and its underlying mechanisms. FAM83D was markedly elevated in triple-negative breast cancer tissues and cells, and high expression of FAM83D was related to the poor prognosis of triple-negative breast cancer patients. FAM83D knockdown significantly retarded cell proliferation, invasion, stemness, and accelerated cell apoptosis in triple-negative breast cancer cells. On the contrary, overexpression of FAM83D promoted the malignant behaviors. METTL3 could interact with FAM83D and mediate m6A modification of FAM838D. Moreover, METTL3 positively regulated FAM83D expression, and FAM83D overexpression could block the inhibition effects of MRTTL3 knockdown on the malignant behaviors. METTL3 knockdown decreased FAM83D expression to inhibit the Wnt/β-catenin pathway. In addition, knockdown of FAM83D also showed the repressive effects on tumor growth in triple-negative breast cancer in vivo. These findings suggested that METTL3 could modulate FAM83D protein expression through m6A modification to aggravate triple-negative breast cancer progression via the Wnt/β-catenin pathway.

Keywords:  FAM83D; METTL3; N6-methyladenosine; Triple-negative breast cancer; Wnt/β-catenin pathway

DOI:  https://doi.org/10.1016/j.tiv.2023.105746
J Transl Med. 2023 Dec 06. 21(1): 882

GATA6-AS1 suppresses epithelial-mesenchymal transition of pancreatic cancer under hypoxia through regulating SNAI1 mRNA stability.

Yunhui Zhou, Xinyi Zhou, Qiwen Ben, Ningning Liu, Jiahui Wang, Yongpeng Zhai, Yichen Bao, Lin Zhou.

  Pancreatic ductal adenocarcinoma (PDAC) is characterized by a hypoxic microenvironment, a high rate of heterogeneity as well as a high likelihood of recurrence. Mounting evidence has affirmed that long non-coding RNAs (lncRNAs) participate in the carcinogenesis of PDAC cells. In this study, we revealed significantly decreased expression of GATA6-AS1 in PDAC based on the GEO dataset and our cohorts, and showed that low GATA6-AS1 expression was linked to unfavorable clinicopathologic characteristics as well as a poor prognosis. Gain- and loss-of-function studies demonstrated that GATA6-AS1 suppressed the proliferation, invasion, migration, and epithelial-mesenchymal transition (EMT) process of PDAC cells under hypoxia. In vivo data confirm the suppressive roles of GATA6-AS1/SNAI1 in tumor growth and lung metastasis of PDAC. Mechanistically, hypoxia-driven E26 transformation-specific sequence-1 (ETS1), as an upstream modulatory mechanism, was essential for the downregulation of GATA6-AS1 in PDAC cells. GATA6-AS1 inhibited the expression of fat mass and obesity-associated protein (FTO), an N6-methyladenosine (m6A) eraser, and repressed SNAI1 mRNA stability in an m6A-dependent manner. Our data suggested that GATA6-AS1 can inhibit PDAC cell proliferation, invasion, migration, EMT process and metastasis under hypoxia, and disrupting the GATA6-AS1/FTO/SNAI1 axis might be a viable therapeutic approach for refractory hypoxic pancreatic cancers.

Keywords:  Epithelial–mesenchymal transition; GATA6-AS1; Hypoxia; N6-Methyladenosine; Pancreatic ductal adenocarcinoma

DOI:  https://doi.org/10.1186/s12967-023-04757-5
PNAS Nexus. 2023 Dec;2(12): pgad390

Systematic assessment of transcriptomic and metabolic reprogramming by blue light exposure coupled with aging.

Jia Huang, Fan Zhou, Huanchan Zhou, Xiaoqi Zheng, Zhengyi Huo, Meng Yang, Zihe Xu, Runzhou Liu, Luoluo Wang, Xiaoyun Wang.

  The prevalent use of light-emitting diodes (LEDs) has caused revolutionary changes in modern life, but the potential hazards to health of blue light are poorly understood. N6-methyladenosine (m6A) is the most prevalent posttranscriptional modification in eukaryotes and can modulate diverse physiological processes by regulating mRNA fate. Here, to understand the effects and molecular mechanisms of daily low-intensity blue light exposure (BLE) and ascertain whether m6A methylation plays a role in BLE-induced phenotypes, we constructed a series of Drosophila models under different durations of daily low-intensity BLE and obtained multiomics profiles. Our results revealed that BLE could induce transcriptomic, m6A epitranscriptomic, and metabolomic reprogramming in Drosophila along with aging process. Importantly, the m6A methylation sites enriched in the 5' untranslated regions (UTRs) of Drosophila transcripts showed strong age specificity and could be altered by BLE. We experimentally validated that aging-related gene Tor and circadian rhythm-related gene per were regulated by 5' UTR-enriched m6A methylation. Overall, our study provides a systematic assessment of m6A RNA methylome reprogramming by BLE and aging in Drosophila model.

Keywords:  RNA methylome; aging; blue light; circadian rhythm

DOI:  https://doi.org/10.1093/pnasnexus/pgad390
PLoS Pathog. 2023 Dec 04. 19(12): e1011808

NSUN2-mediated m5C modification of HBV RNA positively regulates HBV replication.

Jiangpeng Feng, Tianmo Xu, Miao He, Jiali Li, Peipei Yao, Chengbao Ma, Shimin Yang, Zaichao Xu, Kun Yan, Xianying Chen, Hongyun Wang, Jiejie Liu, Cong Zeng, Yuchen Xia, Huan Yan, Li Zhou, Yu Chen.

Chronic hepatitis B virus (HBV) infection is a major cause of liver cirrhosis and liver cancer, despite strong prevention and treatment efforts. The study of the epigenetic modification of HBV has become a research hotspot, including the N6-methyladenosine (m6A) modification of HBV RNA, which plays complex roles in the HBV life cycle. In addition to m6A modification, 5-methylcytosine (m5C) is another major modification of eukaryotic mRNA. In this study, we explored the roles of m5C methyltransferase and demethyltransferase in the HBV life cycle. The results showed that m5C methyltransferase NSUN2 deficiency could negatively regulate the expression of HBV while m5C demethyltransferase TET2 deficiency positively regulates the expression of HBV. Subsequently, we combined both in vitro bisulfite sequencing and high-throughput bisulfite sequencing methods to determine the distribution and stoichiometry of m5C modification in HBV RNA. Two sites: C2017 and C131 with the highest-ranking methylation rates were identified, and mutations at these two sites could lead to the decreased expression and replication of HBV, while the mutation of the "fake" m5C site had no effect. Mechanistically, NSUN2-mediated m5C modification promotes the stability of HBV RNA. In addition, compared with wild-type HepG2-NTCP cells and primary human hepatocytes, the replication level of HBV after NSUN2 knockdown decreased, and the ability of the mutant virus to infect and replicate in wild-type HepG2-NTCP cells and PHHs was substantially impaired. Similar results were found in the experiments using C57BL/6JGpt-Nsun2+/- mice. Interestingly, we also found that HBV expression and core protein promoted the endogenous expression of NSUN2, which implied a positive feedback loop. In summary, our study provides an accurate and high-resolution m5C profile of HBV RNA and reveals that NSUN2-mediated m5C modification of HBV RNA positively regulates HBV replication by maintaining RNA stability.

DOI: https://doi.org/10.1371/journal.ppat.1011808
Redox Biol. 2023 Nov 29. pii: S2213-2317(23)00376-2. [Epub ahead of print]69 102975

Epigenetically upregulated NSUN2 confers ferroptosis resistance in endometrial cancer via m5C modification of SLC7A11 mRNA.

Shuai-Jun Chen, Jun Zhang, Ting Zhou, Shan-Shan Rao, Qian Li, Ling-Yan Xiao, Si-Tian Wei, Hong-Feng Zhang.

  Endometrial cancer (EC) is a prevalent gynecological malignancy worldwide, and 5-methylcytosine (m5C) modification of mRNA is a crucial epigenetic modification associated with the development and occurrence of several cancers. However, the precise function of m5C modification in EC remains elusive. This study aimed to investigate the expression and clinical significance of the primary m5C modification writer, NSUN2, in EC. Our findings indicated that NSUN2 exhibited a substantial up-regulation in EC as a result of an epigenetic augmentation in H3K4me3 levels within the promoter region, which was triggered by the down-regulation of KDM5A. Moreover, gain- and loss-of-function experiments revealed the role of NSUN2 in enhancing m5C modification of mRNA, thereby promoting EC cell proliferation. RNA bisulfite sequencing and transcriptomic sequencing were employed to elucidate the involvement of NSUN2 in the regulation of ferroptosis. Subsequent in vitro experiments confirmed that the knockdown of NSUN2 significantly up-regulated the levels of lipid peroxides and lipid ROS in EC cells, thereby augmenting the susceptibility of EC to ferroptosis. Mechanistically, NSUN2 stimulated the m5C modification of SLC7A11 mRNA, and the m5C reader YBX1 exhibited direct recognition and binding to the m5C sites on SLC7A11 mRNA via its internal cold shock domain (CSD), leading to an increase in SLC7A11 mRNA stability and elevated levels of SLC7A11. Additionally, rescue experiments showed that NSUN2 functioned as a suppressor of ferroptosis, which was dependent on SLC7A11. Overall, targeting the NSUN2/SLC7A11 axis inhibited tumor growth by increasing lipid peroxidation and ferroptosis of EC cells both in vitro and in vivo. Therefore, our study provides new insight into the role of NSUN2, suggesting that NSUN2 may serve as a prognostic biomarker and therapeutic target in patients with EC.

Keywords:  Endometrial cancer; Ferroptosis; NSUN2; SLC7A11; m(5)C

DOI:  https://doi.org/10.1016/j.redox.2023.102975
Anal Chem. 2023 Dec 04.

Isothermal Amplification-Based Detection of Single-Base RNA N6-Methyladenosine.

Ke Zhong, You Wu, Jiangli Zhou, Xianyuan Yang, Cheng Yi, Lichen Ge, Zigang Li, Weiling He, Jie Cao, Guanmin Jiang, Hongsheng Wang, Jiexin Li.

N6-methyladenosine (m6A) has recently gained much attention due to its diverse biological functions. Currently, the commonly used detection methods for locus-specific m6A marks are complicated to operate, it is difficult to quantify the methylation level, and they have high false-positive levels. Here, we report a new method for locus-specific m6A detection based on the methylate-sensitive endonuclease activity of MazF and the simultaneous amplification and testing (SAT) method, termed "m6A-MazF-SAT". Mechanically, MazF fails to cleave the A (m6A) CA motif; therefore, the undigested template can be SAT-amplified using specific probes targeting the upstream and downstream of sites of interest. Fluorescent signals of SAT amplification can be detected by real-time PCR, and therefore, they achieve the detection of m6A existence. After the condition optimization, m6A-MazF-SAT can significantly, accurately, and rapidly detect the m6A-modified sites in mRNA, rRNA, and lncRNA at the fmol level, as well as 10% m6A at the fmol level. In addition, m6A-MazF-SAT can quantify the abundance of target m6A in biological samples and can be used for the inhibitor selection of m6A-related enzymes. Together, we offer a new approach to detect locus-specific m6A both qualitatively and quantitatively; it is easy to operate, results can be obtained rapidly, and it has low false-positive levels and high repeatability.

DOI: https://doi.org/10.1021/acs.analchem.3c03961
Cell Death Dis. 2023 Dec 05. 14(12): 796

Deletion of Mettl3 in mesenchymal stem cells promotes acute myeloid leukemia resistance to chemotherapy.

Xinai Liao, Danni Cai, Jingru Liu, Haoran Hu, Ruolan You, Zhipeng Pan, Shucheng Chen, Kaiming Xu, Wei Dai, Shuxia Zhang, Xinjian Lin, Huifang Huang.

Acute myeloid leukemia (AML) cell survival and chemoresistance are influenced by the existence of bone marrow mesenchymal stem cells (BMMSCs); however, the pathways by which BMMSCs contribute to these processes remain unclear. We earlier revealed that methyltransferase-like 3 (METTL3) expression is significantly reduced in AML BMMSCs and that METTL3 mediates BMMSC adipogenesis to promote chemoresistance in human AML cell lines in vitro. In this investigation, we evaluated the METTL3 function in vivo. Mice exhibiting a conditional removal of Mettl3 in BMMSCs were developed by mating Prrx1-CreERT2;Mettl3fl/+ mice with Mettl3fl/fl mice using the CRISPR-Cas9 system. The Mettl3 deletion increased bone marrow adiposity, enhanced disease progression in the transplantation-induced MLL-AF9 AML mouse model, and chemoresistance to cytarabine. The removal of Mettl3 in BMMSCs resulted in a significant increase in BMMSC adipogenesis. This effect was attributed to the downregulation of AKT1 expression, an AKT serine/threonine kinase 1, in an m6A-dependent manner. The development of chemoresistance in AML is linked to the promoted adipogenesis of BMMSCs. We conclude that METTL3 expression in BMMSCs has a critical function in limiting AML progression and chemoresistance, providing a basis for the progression of therapeutic approaches for AML.

DOI: https://doi.org/10.1038/s41419-023-06325-7
bioRxiv. 2023 Nov 22. pii: 2023.11.22.568301. [Epub ahead of print]

METTL3 alters capping enzyme expression and its activity on ribosomal proteins.

Daniel Del Valle-Morales, Giulia Romano, Patricia Le, Michela Saviana, Rachel Brown, Lavender Micalo, Howard Li, Alessandro La Ferlita, Giovanni Nigita, Patrick Nana-Sinkam, Mario Acunzo.

The 5' cap, catalyzed by RNA guanylyltransferase and 5'-phosphatase (RNGTT), is a vital mRNA modification for the functionality of mRNAs. mRNA capping occurs in the nucleus for the maturation of the functional mRNA and in the cytoplasm for fine-tuning gene expression. Given the fundamental importance of RNGTT in mRNA maturation and expression there is a need to further investigate the regulation of RNGTT. N6-methyladenosine (m 6 A) is one of the most abundant RNA modifications involved in the regulation of protein translation, mRNA stability, splicing, and export. We sought to investigate whether m 6 A could regulate the expression and activity of RNGTT. A motif for the m 6 A writer methyltransferase 3 (METTL3) in the 3'UTR of RNGTT mRNA was identified. Knockdown of METTL3 resulted in destabilizing RNGTT mRNA, and reduced protein expression. Sequencing of capped mRNAs identified an underrepresentation of ribosomal protein mRNA overlapping with 5' terminal oligopyrimidine (TOP) mRNAs and genes are dysregulated when cytoplasmic capping is inhibited. Pathway analysis identified disruptions in the mTOR and p70S6K pathways. A reduction in RPS6 mRNA capping, protein expression, and phosphorylation was detected with METTL3 knockdown.

DOI: https://doi.org/10.1101/2023.11.22.568301
Exp Lung Res. 2023 ;49(1): 220-230

METTL14 knockdown inhibits the pyroptosis in the sepsis-induced acute lung injury through regulating the m6A modification of NLRP3.

Jianting Gao, Huizhen Chen, Yong Zhang, Sun Yu, Yiyi Wu, Qiuyan Wang, Zhenfei Yu.

  Background: Sepsis has become one of the main factors inducing the development of acute lung injury (ALI) in clinical practice. Currently, inhibiting the activation of NLRP3 mediated pyroptosis is the target of multiple drugs in the treatment of sepsis induced ALI. This study aimed to explore the effects of METTL14 on the pyroptosis in the sepsis induced ALI progression.Methods: LPS-stimulated A549 cells and cecal ligation and puncture (CLP)-treated mice were used to establish the ALI model in vitro and in vivo. Then, the cell viability was measured by CCK-8 assay. ELISA kits were used to determine the IL-18 and IL-1β contents. Pyroptosis rate was tested by flow cytometry. M6A dot blot was conducted to analyze the global m6A levels and MeRIP assay was performed to detect the m6A levels of NLRP3. The relationship between METTL14 and NLRP3 was confirmed by RIP and dual-luciferase report assays.Results: The global m6A levels were significantly increased in the LPS-stimulated A549 cells and CLP-treated mice. METTL14 knockdown decreased the cell viability, IL-18 and IL-1β contents, and pyroptosis rate of the LPS-stimulated A549 cells. Furthermore, the increase of pyroptosis-related proteins in LPS-stimulated A549 cells was significantly decreased after METTL14 knockdown. Additionally, METTL14 knockdown decreased the m6A and mRNA levels of NLRP3, and NLRP3 overexpression reversed the effects of METTL14 knockdown on the pyroptosis in the LPS-stimulated A549 cells. In CLP-treated mice, METTL14 knockdown relieved the injury and decreased the IL-18 and IL-1β contents in the lung tissues, serum and bronchoalveolar lavage fluid.Conclusion: This study demonstrated that METTL14 knockdown inhibited the pyroptosis in the sepsis-induced ALI progression through decreasing the NLRP3 levels dependent on m6A methylation modification.

Keywords:  METTL14; NLRP3; Sepsis; acute lung injury; pyroptois

DOI:  https://doi.org/10.1080/01902148.2023.2288182
Environ Res. 2023 Dec 02. pii: S0013-9351(23)02587-2. [Epub ahead of print] 117783

Exosome-shuttled FTO from BM-MSCs contributes to cancer malignancy and chemoresistance in acute myeloid leukemia by inducing m6A-demethylation: A nano-based investigation.

Ruirui Kou, Tian Li, Caizhu Fu, Duanfeng Jiang, Yue Wang, Jie Meng, Ruilan Zhong, Changjiu Liang, Min Dong.

  Although bone marrow mesenchymal stem cells (BM-MSCs)-derived exosomes have been reported to be closely associated with acute myeloid leukemia (AML) progression and chemo-resistance, but its detailed functions and molecular mechanisms have not been fully delineated. Besides, serum RNA m6A demethylase fat mass and obesity-associated protein (FTO)-containing exosomes are deemed as important indicators for cancer progression, and this study aimed to investigate the role of BM-MSCs-derived FTO-exosomes in regulating the malignant phenotypes of AML cells. Here, we verified that BM-MSCs-derived exosomes delivered FTO to promote cancer aggressiveness, stem cell properties and Cytosine arabinoside (Ara-C)-chemoresistance in AML cells, and the underlying mechanisms were also uncovered. Our data suggested that BM-MSCs-derived FTO-exo demethylated m6A modifications in the m6A-modified LncRNA GLCC1 to facilitate its combination with the RNA-binding protein Hu antigen R (HuR), which further increased the stability and expression levels of LncRNA GLCC1. In addition, LncRNA GLCC1 was verified as an oncogene to facilitate cell proliferation and enhanced Ara-C-chemoresistance in AML cells. Further experiments confirmed that demethylated LncRNA GLCC1 served as scaffold to facilitate the formation of the IGF2 mRNA binding protein 1 (IGF2BP1)-c-Myc complex, which led to the activation of the downstream tumor-promoting c-Myc-associated signal pathways. Moreover, our rescuing experiments validated that the promoting effects of BM-MSCs-derived FTO-exo on cancer aggressiveness and drug resistance in AML cells were abrogated by silencing LncRNA GLCC1 and c-Myc. Thus, the present firstly investigated the functions and underlying mechanisms by which BM-MSCs-derived FTO-exo enhanced cancer aggressiveness and chemo-resistance in AML by modulating the LncRNA GLCC1-IGF2BP1-c-Myc signal pathway, and our work provided novel biomarkers for the diagnosis, treatment and therapy of AML in clinic.

Keywords:  Acute myeloid leukemia; Bone marrow mesenchymal stem cells; Derivatives; FTO-Containing exosomes; Leukemic stem cell; N6-methyladenosine

DOI:  https://doi.org/10.1016/j.envres.2023.117783
Am J Cancer Res. 2023 ;13(11): 5289-5305

IGF2BP3-mediated regulation of GLS and GLUD1 gene expression promotes treg-induced immune escape in human cervical cancer.

Tiantian Zhou, Ziyi Xiao, Jin Lu, Lihua Zhang, Le Bo, Jinhua Wang.

This study aimed to investigate the impact of IGF2BP3, a well-known m6A modification-related protein, on the metabolic and immune microenvironment of human cervical cancer. Bioinformatics analysis was performed to analyze the expression of IGF2BP3 in various databases, and its findings were validated using human cervical cancer tissue microarrays. We conducted a study to investigate the impact of IGF2BP3 on glutamine metabolism in cervical cancer cells through the application of metabolomics and metabolic flow analysis. Additionally, we explored how cervical cancer cells promote immune escape by secreting glutamine-derived lactate in a 3D culture setting. To identify the specific targets of IGF2BP3 that influence glutamine metabolism in cervical cancer, we employed RIP-seq analysis. IGF2BP3 exhibited high expression levels in multiple cervical cancer datasets, and its expression was significantly associated with the prognosis of cervical cancer patients. In mixed 3D cell cultures of cervical cancer and T cells, IGF2BP3 was found to enhance glutamate and glutamine metabolism in cervical cancer cells by up regulating the expression of GLS and GLUD1 genes. Moreover, it influenced the differentiation of Treg cells by promoting lactate production and secretion in cervical cancer, leading to immune escape. Mechanistic analysis revealed that IGF2BP3 stabilized the mRNA of GLS and GLUD1 genes through m6A modification, thereby facilitating glutamate and glutamine metabolism in cervical cancer cells and regulating lactate production. Additionally, we investigated the correlation between GLS, GLUD1 protein expression, and IGF2BP3 expression in human cervical cancer through multicolor immunofluorescence staining. The relevance of IGF2BP3 in the context of Treg cell-associated immune escape in cervical cancer was also confirmed. IGF2BP3 exhibits high expression in human cervical cancer and plays a crucial role in stabilizing the mRNA of GLS and GLUD1 genes, key metabolic enzymes in glutamate and glutamine metabolism, through m6A modification. This process leads to immune escape in cervical cancer by promoting lactate production and secretion.

Keywords: IGF2BP3; M6A modification; cervical cancer; glutamine metabolism
Exp Neurol. 2023 Dec 04. pii: S0014-4886(23)00314-X. [Epub ahead of print] 114629

ALKBH5 protects against stroke by reducing endoplasmic reticulum stress-dependent inflammation injury via the STAT5/PERK/EIF2α/CHOP signaling pathway in an m6A-YTHDF1-dependent manner.

Chujuan Liu, Hui Chen, Xi Tao, Chen Li, Aiping Li, Wen Wu.

   BACKGROUND: Endoplasmic reticulum (ER) stress causes neuroinflammation and neuronal apoptosis during ischemic stroke progression. This study has investigated the role of ALKBH5 in ER stress during ischemic stroke progression.
METHODS: In vivo and in vitro models of ischemic stroke were established by middle cerebral artery occlusion (MCAO) and OGD/R treatment, respectively. Cerebral infarct size was detected using triphenyltetrazolium chloride staining (TTC), and pathological changes were examined using histological staining. The levels of inflammatory factors were analyzed using Enzyme-linked immunosorbent assay. Cell counting kit-8 assay and flow cytometry were used to measure cell viability and apoptosis, respectively. The global m6A level was detected using the commercial kit, and STAT5 mRNA m6A level was determined using methylated RNA binding protein immunoprecipitation (Me-RIP). ALKBH5, YTHDF1, and STAT5 interactions were analyzed using RIP and RNA pull-down assays.
RESULTS: ALKBH5 was upregulated in MCAO animals and OGD/R cell models. ALKBH5 knockdown exacerbated ER stress, neuroinflammation, and neuronal apoptosis in brain tissues and neuronal cells. ALKBH5 inhibited STAT5 mRNA stability and expression in an m6A-YTHDF1-dependent manner. STAT5 promoted ER stress by activating the PERK/eIF2/CHOP signaling pathway. Furthermore, STAT5 knockdown reversed the effects of ALKBH5 knockdown on OGD/R-induced ER stress and neuroinflammation in HT22 cells.
CONCLUSION: ALKBH5 knockdown exacerbated ischemic stroke by increasing ER stress-dependent neuroinflammation and neuronal apoptosis via the STAT5/PERK/EIF2α/CHOP signaling pathway in an m6A-YTHDF1-dependent manner.

Keywords:  ALKBH5; Endoplasmic reticulum stress; Ischemic stroke; STAT5

DOI:  https://doi.org/10.1016/j.expneurol.2023.114629
Biol Pharm Bull. 2023 ;46(12): 1797-1804

Fentanyl Promoted the Growth of Placenta Trophoblast Cells through Regulating the METTL14 Mediated CCL5 Levels.

Yongyan Chen, Gaihua Lv, Xiuping Du, Fei Yang, Zhiliang Zhao.

  Gestational diabetes mellitus (GDM) is an important cause of the increase in incidence rate and mortality of pregnant women and perinatal infants. This study aimed to analyze the role of fentanyl, a μ-opioid agonist, in the GDM progression. The high glucose (HG) treatment HTR8/SVneo cells was used as a GDM model in vitro. The cell viability was assessed with cell counting kit-8 assay. The apoptosis rate was analyzed with flow cytometry and the transwell assay was conducted to test the cell migration and invasion. RT-quantitative PCR (qPCR) assay was performed to determine the relative expressions of related genes. The N6-Methyladenosine (m6A) levels were analyzed with MeRIP analysis. The tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β), and IL-10 levels of the cells were analyzed with commercial kits. The results showed that fentanyl increased the cell viability, migration and invasion, and IL-10 levels, and declined the apoptosis rate, TNF-α and IL-1β levels of the HG stimulated HTR8/SVneo cells. The chemokine ligand 5 (CCL5) was over expressed in GDM tissues and HG stimulated HTR8/SVneo cells, which was depleted after fentanyl treatment. Over expressed CCL5 neutralized the fentanyl roles in the HG stimulated HTR8/SVneo cells. The methyltransferase-like protein 14 (METTL14) levels was decreased in HG stimulated HTR8/SVneo cells, which was up-regulated after fentanyl treatment. Additionally, METTL14 silenced prominently decreased the m6A and mRNA levels, along with the mRNA stability of CCL5. In conclusion, fentanyl promoted the growth and inhibited the apoptosis of the HG stimulated HTR8/SVneo cells through regulating the METTL14 mediated CCL5 levels.

Keywords:  chemokine ligand 5; fentanyl; gestational diabetes mellitus; methyltransferase-like protein 14

DOI:  https://doi.org/10.1248/bpb.b23-00531
Neoplasma. 2023 Oct;pii: 230104N7. [Epub ahead of print]70(5): 659-669

TRIM11 regulated by m6A modification promotes the progression of cervical cancer by PHLPP1 ubiquitination.

Pu Zhang, Yi Tang, Jing Zhao, Jing Yang, Yan Chen, Yingping Gong, Shengjun Meng, Chuqiang Shu.

Cervical cancer (CC) is a common cancer in women and a serious threat to women's lives. TRIM11 has been confirmed as a carcinogen in multiple cancers. Here, we will excavate the detailed mechanism of TRIM11 in CC. CC cell lines and nude mice were experimental subjects in this study. The abundance of genes and proteins was detected using qRT-PCR, western blot, and IHC. Cell proliferation, migration, and invasion were determined by CCK-8 assay, wound healing assay, and Transwell, respectively. The interactions among METTL14, TRIM11, and PHLPP1 were confirmed using RIP and co-IP, respectively. The stability of TRIM11 mRNA was examined by qRT-PCR with actinomycin D treatment. The m6A level of TRIM11 was detected by MeRIP assay. Results showed that TRIM11 levels were elevated in CC cells. TRIM11 depletion attenuated the proliferation, migration, and invasion of Hela and SiHa cells. Additionally, TRIM11 was modified with m6A, which was mediated by METTL14, and the stability of TRIM11 mRNA was enhanced by IGF2BP1 depending on the level of m6A modification. TRIM11 ubiquitinated PHLPP1 and led to reduced PHLPP1 expression at the protein level. PHLPP1 could further result in the dephosphorylation of AKT and inhibit AKT signaling. PHLPP1 knockdown neutralized TRIM11 silencing-mediated repression of malignant phenotypes of CC cells. TRIM11 mediated by the METTL14-IGF2BP1 axis promotes the AKT pathway to accelerate CC progression by mediating the ubiquitination of PHLPP, which might provide novel therapeutic targets for CC treatment.

DOI: https://doi.org/10.4149/neo_2023_230104N7
Cell Signal. 2023 Dec 02. pii: S0898-6568(23)00417-5. [Epub ahead of print] 111002

M6A reader YTHDF1 promotes malignant progression of laryngeal squamous carcinoma through activating the EMT pathway by EIF4A3.

Huina Guo, Qi Han, Xiaoya Guan, Zhongxun Li, Ying Wang, Long He, Yujia Guo, Liting Zhao, Xuting Xue, Hongliang Liu, Chunming Zhang.

  Laryngeal squamous cell carcinoma (LSCC) is one of the common malignant tumors in the head and neck region, and its high migration and invasion seriously threaten the survival and health of patients. In cancer development, m6A RNA modification plays a crucial role in regulating gene expression and signaling. This study delved into the function and mechanism of the m6A reading protein YTHDF1 in LSCC. It was found that YTHDF1 was highly expressed in the TCGA database and LSCC tissues. Cell function experiments confirmed that the downregulation of YTHDF1 significantly inhibited the proliferation, migration, and invasion ability of LSCC cells. Further studies revealed that EIF4A3 was a downstream target gene of YTHDF1, and knockdown of EIF4A3 similarly significantly inhibited the malignant progression of LSCC in both in vivo and in vitro experiments. The molecular mechanism studies suggested that YTHDF1-EIF4A3 may promote the malignant development of LSCC by activating the EMT signaling pathway. This study provides important clues for an in-depth understanding of the pathogenesis of LSCC and is a solid foundation for the discovery of new therapeutic targets and approaches.

Keywords:  EIF4A3; EMT; Laryngeal squamous cell carcinoma; YTHDF1; m6A

DOI:  https://doi.org/10.1016/j.cellsig.2023.111002
Environ Toxicol. 2023 Dec 05.

Loss of MTA2-mediated downregulation of PTK7 inhibits hepatocellular carcinoma metastasis progression by modulating the FAK-MMP7 axis.

Huang-Ming Hu, Hsiang-Lin Lee, Chung-Jung Liu, Yi-Hsien Hsieh, Yong-Syuan Chen, Kuan-Chun Hsueh.

  The expression of metastasis tumor-associated protein 2 (MTA2) and protein tyrosine kinase 7 (PTK7) is associated with hepatocellular carcinoma (HCC) progression. However, the functional effect and mechanism through which MTA2 regulates PTK7-mediated HCC progression remains unclear. Here, we found that MTA2 knockdown significantly down-regulated PTK7 expression in HCC cells (SK-Hep-1 and PLC/PRF/5). Data from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases show that the PTK7 expression level was higher in HCC tissues than in normal liver tissues. In HCC patients, the PTK7 expression level clearly correlated with tumor stage and grade, lower overall survival (OS) correlated positively with MTA2 level, and PTK7 expression acted as a downstream factor for MTA2 expression. In addition, matrix metalloproteinase 7 (MMP7) expression was closely regulated by PTK7, and the mRNA and protein expression levels of MTA2 and PTK7 correlated positively with lower OS. MMP7 downregulation by PTK7 knockdown clearly decreased the migration and invasion abilities of HCC cells. In HCC cells, recombinant human MMP7 reversed the PTK7 knockdown-induced suppression of migration and invasion. Furthermore, deactivation of FAK using siFAK or FAK inhibitor (PF-573228, PF) synergistically contributed to PTK7 knockdown-inhibited FAK activity, MMP7 expression, and the migration and invasion abilities of HCC cells. Collectively, our findings show that PTK7 mediates HCC progression by regulating the MTA2-FAK-MMP7 axis and may be a diagnostic value for HCC patients.

Keywords:  hepatocellular carcinoma; invasion; matrix metalloproteinase 7; metastasis tumor-associated protein-2; migration; protein tyrosine kinase 7

DOI:  https://doi.org/10.1002/tox.24073
Am J Cancer Res. 2023 ;13(11): 5320-5333

Silencing of m6A methyltransferase KIAA1429 suppresses the progression of non-small cell lung cancer by promoting the p53 signaling pathway and ferroptosis.

Yuanzhou Wu, Hui Li, Yang Huang, Qunqing Chen.

KIAA1429, an important component of the N6-methyladenine methyltransferase complex, is involved in the pathology of many types of cancer. In this study, the mechanisms through which KIAA1429 promotes non-small cell lung cancer (NSCLC) progression were explored using in vitro and in vivo experiments. Additionally, bioinformatics analysis of publicly available data was used to determine the relationship between KIAA1429 expression and NSCLC patient survival. The results showed that KIAA1429 was upregulated in NSCLC tissues and cells, and its high expression level was associated with low overall survival. Transcriptome analysis of KIAA1429-silenced NSCLC cells identified 346 differentially expressed genes, which were enriched in ferroptosis and the p53 signaling pathway. KIAA1429 silencing using small interfering (si) RNA promoted erastin-induced ferroptosis in NSCLC cells and activated the p53 signaling pathway. Moreover, si-KIAA1429 inhibited the proliferative, migratory, and invasive abilities of NSCLC cells in vitro and tumor growth in vivo. These in vitro effects were weakened by pifithrin-μ, a p53 inhibitor. Therefore, given its effects on ferroptosis and the p53 signaling pathway, targeting KIAA1429 could be an effective strategy for treating NSCLC.

Keywords: KIAA1429; N6-methyladenine; Non-small cell lung cancer; ferroptosis; p53 signaling pathway
Oncogene. 2023 Dec 04.

FOXO3a-regulated arginine metabolic plasticity adaptively promotes esophageal cancer proliferation and metastasis.

Wenbo Sun, Hengyuan Kou, Yao Fang, Fan Xu, Zhi Xu, Xiumei Wang, Rong Yin, Qin Zhang, Qin Jiang, Yong Xu.

Esophageal squamous cell carcinoma (ESCC) is a common malignant tumor with a poor prognosis due to a lack of early detection. Indeed, the mechanisms underlying ESCC progression remain unclear. Here, we discovered that abnormal arginine metabolism contributes to ESCC progression. Based on transcriptomic and metabolomic analyses, we found that argininosuccinate synthetase 1 (ASS1) and argininosuccinate lyase (ASL) levels were increased in primary tumor tissues but decreased in lymph-metastatic tumor tissues. Intriguingly, FOXO3a was inversely correlated with ASS1 and ASL in primary and metastatic tumor tissues, suggesting that FOXO3a dissimilarly regulates ASS1 and ASL at different stages of ESCC. Silencing ASS1/ASL inhibited primary tumor growth and promoted metastasis. Conversely, overexpression of ASS1/ASL or increased arginine supply promoted tumor proliferation but suppressed metastasis. In addition, FOXO3a activation inhibited primary tumor growth by repressing ASS1 and ASL transcription, whereas inactivation of FOXO3a impeded metastasis by releasing ASS1 and ASL transcription. Together, the finding sheds light on metastatic reprogramming in ESCC.

DOI: https://doi.org/10.1038/s41388-023-02906-0
iScience. 2023 Dec 15. 26(12): 108340

ABHD12 contributes to tumorigenesis and sorafenib resistance by preventing ferroptosis in hepatocellular carcinoma.

Mengxing Cai, Jingwen Luo, Chunxiu Yang, Xiaopeng Yang, Cheng Zhang, Lixin Ma, Yibin Cheng.

  Sorafenib induces ferroptosis, making it a useful treatment against advanced liver hepatocellular carcinoma (LIHC). However, sorafenib resistance is extremely common among LIHC patients. Here, we used a comprehensive approach to investigate the effects of ABHD12, which regulates tumorigenesis and sorafenib resistance in LIHC. We validated ABHD12 expression was upregulated in LIHC tissue, which correlated with worse overall survival and related to tumor size or stage. ABHD12 facilitated a pro-tumorigenic phenotype involving increased cell proliferation, migration, and clonogenicity as well as sorafenib resistance. Knockout of ABHD12 sensitized liver cancer cells to sorafenib-induced ferroptosis. Co-delivery of sorafenib and ABHD12 inhibitor into a nude mouse model enhanced therapeutic efficacy for LIHC. Our study demonstrates that ABHD12 contributes to tumor growth and sorafenib resistance in liver cancer, which indicate the promising potential of ABHD12 in diagnosis and prognosis as well as highlight the potential therapeutic applications for co-delivery of sorafenib and ABHD12 inhibitor.

Keywords:  Biological sciences; Cancer; Cancer systems biology; Natural sciences; Pharmacology; Systems biology

DOI:  https://doi.org/10.1016/j.isci.2023.108340
Cancer Cell Int. 2023 Dec 02. 23(1): 308

Circular RNA circEYA3 promotes the radiation resistance of hepatocellular carcinoma via the IGF2BP2/DTX3L axis.

Pan Hu, Letao Lin, Tao Huang, Zhenyu Li, Meigui Xiao, Huanqing Guo, Guanyu Chen, Dengyao Liu, Miaola Ke, Hongbo Shan, Fujun Zhang, Yanling Zhang.

   BACKGROUND: Hepatocellular carcinoma (HCC) has a high incidence and mortality rate despite various treatment options, including 125I seed implantation. However, recurrence and radiation resistance remain challenging issues. Hsa_circ_0007895 (circEYA3)-derived from exons 2-6 of EYA3-facilitates the proliferation and progression of pancreatic ductal adenocarcinoma. However, the role of circEYA3 in HCC 125I radiation resistance remains unclear. Thus, we aimed to investigate the functions and underlying molecular mechanisms of circEYA3 in HCC under 125I and X-ray irradiation conditions.
METHODS: CircEYA3 was identified by RNA-seq in patients with HCC before and after 125I seed implantation treatment, followed by fluorescence in situ hybridization and RNase R assays. The radiosensitivity of HCC cell lines irradiated with 125I seeds or external irradiation were evaluated using the Cell Counting Kit 8, flow cytometry, γH2A.X immunofluorescence and comet assays. RNA pull-down and RNA immunoprecipitation assays were performed to explore the interactions between circEYA3 and IGF2BP2. DTX3L mRNA was identified by RNA-seq in PLC/PRF/5 cells with overexpressed circEYA3. The corresponding in vitro results were verified using a mouse xenograft model.
RESULTS: CircEYA3 decreased the radiosensitivity of HCC cells both in vitro and in vivo. Notably, using a circRNA pulldown assay and RNA-binding protein immunoprecipitation, we identified IGF2BP2 as a novel and robust interacting protein of circEYA3. Mechanistically, circEYA3 binds to IGF2BP2 and enhances its ability to stabilize DTX3L mRNA, thereby specifically alleviating radiation-induced DNA damage in HCC cells.
CONCLUSIONS: Our findings demonstrate that circEYA3 increases the radioresistance of HCC to 125I seeds and external irradiation via the IGF2BP2/DTX3L axis. Thus, circEYA3 might be a predictive indicator and intervention option for 125I brachytherapy or external radiotherapy in HCC.

Keywords:  125I brachytherapy; Circular RNA; RNA-binding protein; Radiation resistance

DOI:  https://doi.org/10.1186/s12935-023-03168-2