bims-glucam 2024-02-18 papers

bims-glucam

Biomed News

on Glutamine cancer metabolism

Issue of 2024–02–18
fiveteen papers selected by
Sreeparna Banerjee, Middle East Technical University

The role of glutamate and glutamine metabolism and related transporters in nerve cells.
Glutaminase potentiates the glycolysis in esophageal squamous cell carcinoma by interacting with PDK1.
tRF-29-79 regulates lung adenocarcinoma progression through mediating glutamine transporter SLC1A5.
Set7/9 aggravates ischemic brain injury via enhancing glutamine metabolism in a blocking Sirt5 manner.
Targeting myeloma metabolism: How abnormal metabolism contributes to multiple myeloma progression and resistance to proteasome inhibitors.
Phospholipase D mediates glutamine-induced mTORC1 ac-tivation to promote porcine intestinal epithelial cell prolifer-ation.
SLC25A51 decouples the mitochondrial NAD+/NADH ratio to control proliferation of AML cells.
Altered expression of GLS2 indicates a poor prognosis and correlates with clinicopathological features of oral squamous cell carcinoma.
Abundant urinary amino acids activate glutamine synthetase-encoding glnA by two different mechanisms in Escherichia coli.
Metabolic phenotyping and global functional analysis facilitate metabolic signature discovery for tuberculosis treatment monitoring.
Cystine deprivation triggers CD36-mediated ferroptosis and dysfunction of tumor infiltrating CD8+ T cells.
Design of Novel 18F-Labeled Amino Acid Tracers Using Sulfur 18F-Fluoride Exchange Click Chemistry.
New plasma diagnostic markers for colorectal cancer: transporter fragments of glutamate tRNA origin.
Silver nanoparticle functionalized by glutamine and conjugated with thiosemicarbazide induces apoptosis in colon cancer cell line.
Nuclear factor erythroid 2-related factor 2 promotes radioresistance by regulating glutamate-cysteine ligase modifier subunit and its unique immunoinvasive pattern.

CNS Neurosci Ther. 2024 Feb;30(2): e14617

The role of glutamate and glutamine metabolism and related transporters in nerve cells.

Dongyang Zhang, Zhongyan Hua, Zhijie Li.

   BACKGROUND: Glutamate and glutamine are the most abundant amino acids in the blood and play a crucial role in cell survival in the nervous system. Various transporters found in cell and mitochondrial membranes, such as the solute carriers (SLCs) superfamily, are responsible for maintaining the balance of glutamate and glutamine in the synaptic cleft and within cells. This balance affects the metabolism of glutamate and glutamine as non-essential amino acids.
AIMS: This review aims to provide an overview of the transporters and enzymes associated with glutamate and glutamine in neuronal cells.
DISCUSSION: We delve into the function of glutamate and glutamine in the nervous system by discussing the transporters involved in the glutamate-glutamine cycle and the key enzymes responsible for their mutual conversion. Additionally, we highlight the role of glutamate and glutamine as carbon and nitrogen donors, as well as their significance as precursors for the synthesis of reduced glutathione (GSH).
CONCLUSION: Glutamate and glutamine play a crucial role in the brain due to their special effects. It is essential to focus on understanding glutamate and glutamine metabolism to comprehend the physiological behavior of nerve cells and to treat nervous system disorders and cancer.

Keywords:  glutamate metabolism; glutamate transporters; glutamine metabolism; glutamine transporters; nerve cells

DOI:  https://doi.org/10.1111/cns.14617
Mol Carcinog. 2024 Feb 14.

Glutaminase potentiates the glycolysis in esophageal squamous cell carcinoma by interacting with PDK1.

Guangzhao Zhu, Fangxia Guan, Shenglei Li, Qing Zhang, Xueying Zhang, Yue Qin, Zhangzhan Sun, Shaohua Peng, Jiexing Cheng, Yiyang Li, Ruili Ren, Tianli Fan, Hongtao Liu.

  Increasing evidence has demonstrated that glutaminase (GLS) as a key mitochondrial enzyme plays a pivotal role in glutaminolysis, which widely participates in glutamine metabolism serving as main energy sources and building blocks for tumor growth. However, the roles and molecular mechanisms of GLS in esophageal squamous cell carcinoma (ESCC) remains unknown. Here, we found that GLS was highly expressed in ESCC tissues and cells. GLS inhibitor CB-839 significantly suppressed cell proliferation, colony formation, migration and invasion of ESCC cells, whereas GLS overexpression displayed the opposite effects. In addition, CB-839 markedly suppressed glucose consumption and lactate production, coupled with the downregulation of glycolysis-related proteins HK2, PFKM, PKM2 and LDHA, whereas GLS overexpression exhibited the adverse results. In vivo animal experiment revealed that CB-839 dramatically suppressed tumor growth, whereas GLS overexpression promoted tumor growth in ESCC cells xenografted nude mice. Mechanistically, GLS was localized in mitochondria of ESCC cells, which interacted with PDK1 protein. CB-839 attenuated the interaction of GLS and PDK1 in ESCC cells by suppressing PDK1 expression, which further evoked the downregulation of p-PDHA1 (s293), however, GLS overexpression markedly enhanced the level of p-PDHA1 (s293). These findings suggest that interaction of GLS with PDK1 accelerates the glycolysis of ESCC cells by inactivating PDH enzyme, and thus targeting GLS may be a novel therapeutic approach for ESCC patients.

Keywords:  esophageal squamous cell carcinoma; glutaminase; glycolysis; pyruvate dehydrogenase E1 subunit alpha 1; pyruvate dehydrogenase kinase isoform 1

DOI:  https://doi.org/10.1002/mc.23696
Carcinogenesis. 2024 Feb 15. pii: bgae010. [Epub ahead of print]

tRF-29-79 regulates lung adenocarcinoma progression through mediating glutamine transporter SLC1A5.

Yuanjian Shi, Zehao Pan, Yipeng Feng, Qinyao Zhou, Qinglin Wang, Hui Wang, Gaochao Dong, Wenjie Xia, Feng Jiang.

  In recent decades, considerable evidence has emerged indicating the involvement of tRNA-derived fragments (tRFs) in cancer progression through various mechanisms. However, the biological effects and mechanisms of tRFs in lung adenocarcinoma (LUAD) remain unclear. In this study, we screen out tRF-29-79, a 5'-tRF derived from tRNAGlyGCC, through profiling the tRF expressions in three pairs of LUAD tissues. We show that tRF-29-79 is down-regulated in LUAD and down-regulation of tRF-29-79 is associated with poorer prognosis. In vivo and in vitro assay reveal that tRF-29-79 inhibits proliferation, migration, and invasion of LUAD cells. Mechanistically, we discovered that tRF-29-79 interacts with the RNA-binding protein PTBP1 and facilitates the transportation of PTBP1 from nucleus to cytoplasm, which regulates alternative splicing in the 3' untranslated region (UTR) of SLC1A5 pre-mRNA. Given that SLC1A5 is a core transporter of glutamine, we proved that tRF-29-79 mediate glutamine metabolism of LUAD through affecting the stability of SLC1A5 mRNA, thus exerts its anticancer function. In summary, our findings uncover the novel mechanism that tRF-29-79 participates in glutamine metabolism through interacting with PTBP1 and regulating alternative splicing in the 3' UTR of SLC1A5 pre-mRNA.

Keywords:  Glutamine metabolism; Lung adenocarcinoma; PTBP1; SLC1A5; tRF-29-79; tRFs

DOI:  https://doi.org/10.1093/carcin/bgae010
Cell Death Differ. 2024 Feb 16.

Set7/9 aggravates ischemic brain injury via enhancing glutamine metabolism in a blocking Sirt5 manner.

Jinghuan Wang, Subei Tan, Yuyu Zhang, Jie Xu, Yuhui Li, Qianwen Cheng, Chen Ding, Xinhua Liu, Jun Chang.

The aberrant expression of methyltransferase Set7/9 plays a role in various diseases. However, the contribution of Set7/9 in ischemic stroke remains unclear. Here, we show ischemic injury results in a rapid elevation of Set7/9, which is accompanied by the downregulation of Sirt5, a deacetylase reported to protect against injury. Proteomic analysis identifies the decrease of chromobox homolog 1 (Cbx1) in knockdown Set7/9 neurons. Mechanistically, Set7/9 promotes the binding of Cbx1 to H3K9me2/3 and forms a transcription repressor complex at the Sirt5 promoter, ultimately repressing Sirt5 transcription. Thus, the deacetylation of Sirt5 substrate, glutaminase, which catalyzes the hydrolysis of glutamine to glutamate and ammonia, is decreased, promoting glutaminase expression and triggering excitotoxicity. Blocking Set7/9 eliminates H3K9me2/3 from the Sirt5 promoter and normalizes Sirt5 expression and Set7/9 knockout efficiently ameliorates brain ischemic injury by reducing the accumulation of ammonia and glutamate in a Sirt5-dependent manner. Collectively, the Set7/9-Sirt5 axis may be a promising epigenetic therapeutic target.

DOI: https://doi.org/10.1038/s41418-024-01264-y
Neoplasia. 2024 Feb 15. pii: S1476-5586(24)00011-3. [Epub ahead of print]50 100974

Targeting myeloma metabolism: How abnormal metabolism contributes to multiple myeloma progression and resistance to proteasome inhibitors.

Xiang Zhou, Rui He, Wei-Xin Hu, Saiqun Luo, Jingping Hu.

  Multiple myeloma is a hematological malignancy that has evolved from antibody-secreting B lymphocytes. Like other types of cancers, myeloma cells have acquired functional capabilities which are referred to as "Hallmarks of Cancer", and one of their most important features is the metabolic disorders. Due to the high secretory load of the MM cells, the first-line medicine proteasome inhibitors have found their pronounced effects in MM cells for blocking the degradation of misfolded proteins, leading to their accumulation in the ER and overwhelming ER stress. Moreover, proteasome inhibitors have been reported to be effective in myeloma by targeting glucose, lipid, amino acid metabolism of MM cells. In this review, we have described the abnormal metabolism of the three major nutrients, such as glucose, lipid and amino acids, which participate in the cellular functions. We have described their roles in myeloma progression, how they could be exploited for therapeutic purposes, and current therapeutic strategies targeting these metabolites, hoping to uncover potential novel therapeutic targets and promote the development of future therapeutic approaches.

Keywords:  Cancer metabolism; Multiple myeloma; Warburg effect

DOI:  https://doi.org/10.1016/j.neo.2024.100974
J Nutr. 2024 Feb 14. pii: S0022-3166(24)00096-8. [Epub ahead of print]

Phospholipase D mediates glutamine-induced mTORC1 ac-tivation to promote porcine intestinal epithelial cell prolifer-ation.

Min Zhu, En-Qing Lu, Ling Yan, Guowei Liu, Ke Huang, E Xu, Yi-Yu Zhang, Xiang-Guang Li.

   BACKGROUND: The intestinal epithelium is one of the fastest self-renewal tissues in the body, and glutamine plays a crucial role in providing carbon and nitrogen for biosynthesis. In intestinal homeostasis, phosphorylation-mediated signaling networks that cause altered cell proliferation, differentiation, and metabolic regulation have been observed. However, our understanding of how glutamine affects protein phosphorylation in the intestinal epithelium is limited, and identifying the essential signaling pathways involved in regulating intestinal epithelial cell growth is particularly challenging.
OBJECTIVE: This study aimed to identify the essential proteins and signaling pathways involved in glutamine's promotion of porcine intestinal epithelial cell (IPEC-J2) proliferation.
METHODS: Phosphoproteomics was applied to describe the protein phosphorylation landscape under glutamine treatment. Kinase-Substrate Enrichment Analysis (KSEA) was subjected to predict kinase activity, and validated by RT-qPCR and Western blotting. CCK8, Glutamine rescue experiment, Chloroquine (CQ) treatment, and FIPI inhibition assay revealed the possible underlying mechanism of glutamine promoting IEPC-J2 cell proliferation.
RESULTS: In this study, glutamine starvation was found to significantly suppress the proliferation of intestinal epithelial cells and change phosphoproteomic profiles with 575 downregulated sites and 321 upregulated sites. Interestingly, phosphorylation of 4EBP1 at position Thr70 was decreased, which is a crucial downstream of the mechanistic target of rapamycin complex 1 (mTORC1) pathway. Further studies showed that glutamine supplementation rescued cell proliferation and mTORC1 activity, dependent on lysosomal function and phospholipase D (PLD) activation.
CONCLUSIONS: In conclusion, glutamine activates mTORC1 signaling dependent on PLD and a functional lysosome to promote intestinal epithelial cell proliferation. This discovery provides new insight into regulating the homeostasis of the intestinal epithelium, particularly in pig production.

Keywords:  cell proliferation; glutamine; intestinal epithelium; mTORC1; phospholipase D

DOI:  https://doi.org/10.1016/j.tjnut.2024.02.010
Cell Metab. 2024 Feb 13. pii: S1550-4131(24)00013-5. [Epub ahead of print]

SLC25A51 decouples the mitochondrial NAD+/NADH ratio to control proliferation of AML cells.

Mu-Jie Lu, Jonathan Busquets, Valeria Impedovo, Crystal N Wilson, Hsin-Ru Chan, Yu-Tai Chang, William Matsui, Stefano Tiziani, Xiaolu A Cambronne.

  SLC25A51 selectively imports oxidized NAD+ into the mitochondrial matrix and is required for sustaining cell respiration. We observed elevated expression of SLC25A51 that correlated with poorer outcomes in patients with acute myeloid leukemia (AML), and we sought to determine the role SLC25A51 may serve in this disease. We found that lowering SLC25A51 levels led to increased apoptosis and prolonged survival in orthotopic xenograft models. Metabolic flux analyses indicated that depletion of SLC25A51 shunted flux away from mitochondrial oxidative pathways, notably without increased glycolytic flux. Depletion of SLC25A51 combined with 5-azacytidine treatment limits expansion of AML cells in vivo. Together, the data indicate that AML cells upregulate SLC25A51 to decouple mitochondrial NAD+/NADH for a proliferative advantage by supporting oxidative reactions from a variety of fuels. Thus, SLC25A51 represents a critical regulator that can be exploited by cancer cells and may be a vulnerability for refractory AML.

Keywords:  AML; MCART1; SLC25A51; glutamine utilization; oxidative mitochondria; tumor metabolism

DOI:  https://doi.org/10.1016/j.cmet.2024.01.013
Int J Oral Maxillofac Surg. 2024 Feb 10. pii: S0901-5027(24)00029-8. [Epub ahead of print]

Altered expression of GLS2 indicates a poor prognosis and correlates with clinicopathological features of oral squamous cell carcinoma.

B Kannan, C Pandi, A Pandi, V P Jayaseelan, S Murugan M, P Arumugam.

  Glutamine metabolism, governed by enzymes including glutaminase (GLS1 and GLS2), has a pivotal role in cancer progression. The objective of this study was to determine whether GLS2 transcription levels are associated with oral squamous cell carcinoma (OSCC) when compared to matched adjacent normal tissues. Primary tumour and adjacent normal tissues were collected from 51 OSCC patients, and GLS2 mRNA expression analysis was conducted using real-time qPCR. Additionally, The Cancer Genome Atlas-Head and Neck Squamous Cell Carcinoma (TCGA-HNSCC) dataset was utilized to examine GLS2 expression in relation to clinicopathological features, the prognosis, and tumour immune cell infiltration. A significantly reduced expression of GLS2 mRNA was found in the OSCC tissues when compared to the matched adjacent normal tissue samples (P < 0.001), which aligned with the results from the TCGA-HNSCC dataset and immunohistochemistry. Moreover, GLS2 mRNA expression was associated with clinicopathological features including tumour stage, grade, and human papillomavirus status (all P < 0.05), predicted a poorer prognosis (P = 0.024), and was correlated with tumour immune cell infiltration (all P < 0.05) in head and neck squamous cell carcinoma. Functional pathway analysis indicated its involvement in cell proliferation and metabolic cycles. GLS2 dysregulation is linked to oral cancer, suggesting its potential as a predictive prognostic marker for OSCC. Furthermore, targeting glutaminases via GLS2 may represent a promising therapeutic strategy for OSCC treatment.

Keywords:  Cancer; Genetics; Mitochondrial protein; Mortality; Oral squamous cell carcinoma; Prognosis

DOI:  https://doi.org/10.1016/j.ijom.2024.01.011
J Bacteriol. 2024 Feb 15. e0037623

Abundant urinary amino acids activate glutamine synthetase-encoding glnA by two different mechanisms in Escherichia coli.

Karthik Urs, Philippe E Zimmern, Larry Reitzer.

  Growth of uropathogenic Escherichia coli in the bladder induces transcription of glnA which codes for the ammonia-assimilating glutamine synthetase (GS) despite the normally suppressive high ammonia concentration. We previously showed that the major urinary component, urea, induces transcription from the Crp-dependent glnAp1 promoter, but the urea-induced transcript is not translated. Our purpose here was to determine whether the most abundant urinary amino acids, which are known to inhibit GS activity in vitro, also affect glnA transcription in vivo. We found that the abundant amino acids impaired growth, which glutamine and glutamate reversed; this implies inhibition of GS activity. In strains with deletions of crp and glnG that force transcription from the glnAp2 and glnAp1 promoters, respectively, we examined growth and glnA transcription with a glnA-gfp transcriptional fusion and quantitative reverse transcription PCR with primers that can distinguish transcription from the two promoters. The abundant urinary amino acids stimulated transcription from the glnAp2 promoter in the absence of urea but from the glnAp1 promoter in the presence of urea. However, transcription from glnAp1 did not produce a translatable mRNA or GS as assessed by a glnA-gfp translational fusion, enzymatic assay of GS, and Western blot to detect GS antigen in urea-containing media. We discuss these results within the context of the extremely rapid growth of uropathogenic E. coli in urine, the different factors that control the two glnA promoters and possible mechanisms that either overcome or bypass the urea-imposed block of glutamine synthesis during bacterial growth in urine.IMPORTANCEKnowledge of the regulatory mechanisms for genes expressed at the site of infection provides insight into the virulence of pathogenic bacteria. During urinary tract infections-most often caused by Escherichia coli-growth in urine induces the glnA gene which codes for glutamine synthetase. The most abundant urinary amino acids amplified the effect of urea which resulted in hypertranscription from the glnAp1 promoter and, unexpectedly, an untranslated transcript. E. coli must overcome this block in glutamine synthesis during growth in urine, and the mechanism of glutamine acquisition or synthesis may suggest a possible therapy.

Keywords:  Escherichia coli; glutamine synthetase; urinary tract infections; urine composition

DOI:  https://doi.org/10.1128/jb.00376-23
Biochim Biophys Acta Mol Basis Dis. 2024 Feb 10. pii: S0925-4439(24)00053-X. [Epub ahead of print]1870(4): 167064

Metabolic phenotyping and global functional analysis facilitate metabolic signature discovery for tuberculosis treatment monitoring.

Nguyen Ky Anh, Nguyen Thi Hai Yen, Nguyen Tran Nam Tien, Nguyen Ky Phat, Young Jin Park, Ho-Sook Kim, Dinh Hoa Vu, Jee Youn Oh, Dong Hyun Kim, Nguyen Phuoc Long.

  Tracking alterations in polar metabolite and lipid levels during anti-tuberculosis (TB) interventions is an emerging biomarker discovery and validation approach due to its sensitivity in capturing changes and reflecting on the host status. Here, we employed deep plasma metabolic phenotyping to explore the TB patient metabolome during three phases of treatment: at baseline, during intensive phase treatment, and upon treatment completion. Differential metabolites (DMs) in each period were determined, and the pathway-level biological alterations were explored by untargeted metabolomics-guided functional interpretations that bypassed identification. We identified 41 DMs and 39 pathways that changed during intensive phase completion. Notably, levels of certain amino acids including histidine, bile acids, and metabolites of purine metabolism were dramatically increased. The altered pathways included those involved in the metabolism of amino acids, glycerophospholipids, and purine. At the end of treatment, 44 DMs were discovered. The levels of glutamine, bile acids, and lysophosphatidylinositol significantly increased compared to baseline; the levels of carboxylates and hypotaurine declined. In addition, 37 pathways principally associated with the metabolism of amino acids, carbohydrates, and glycan altered at treatment completion. The potential of each DM for diagnosing TB was examined using a cohort consisting of TB patients, those with latent infections, and controls. Logistic regression revealed four biomarkers (taurine, methionine, glutamine, and acetyl-carnitine) that exhibited excellent performance in differential diagnosis. In conclusion, we identified metabolites that could serve as useful metabolic signatures for TB management and elucidated underlying biological processes affected by the crosstalk between host and TB pathogen during treatment.

Keywords:  Biomarker; Diagnosis; Metabolomics; Treatment monitoring; Tuberculosis

DOI:  https://doi.org/10.1016/j.bbadis.2024.167064
Cell Death Dis. 2024 Feb 15. 15(2): 145

Cystine deprivation triggers CD36-mediated ferroptosis and dysfunction of tumor infiltrating CD8+ T cells.

Chenfeng Han, Minmin Ge, Pengfei Xing, Tian Xia, Cangang Zhang, Kaili Ma, Yifu Ma, Shicheng Li, Wenhui Li, Xiaowei Liu, Baojun Zhang, Liyuan Zhang, Lianjun Zhang.

Cancer cells develop multiple strategies to evade T cell-mediated killing. On one hand, cancer cells may preferentially rely on certain amino acids for rapid growth and metastasis. On the other hand, sufficient nutrient availability and uptake are necessary for mounting an effective T cell anti-tumor response in the tumor microenvironment (TME). Here we demonstrate that tumor cells outcompete T cells for cystine uptake due to high Slc7a11 expression. This competition induces T-cell exhaustion and ferroptosis, characterized by diminished memory formation and cytokine secretion, increased PD-1 and TIM-3 expression, as well as intracellular oxidative stress and lipid-peroxide accumulation. Importantly, either Slc7a11 deletion in tumor cells or intratumoral cystine supplementation improves T cell anti-tumor immunity. Mechanistically, cystine deprivation in T cells disrupts glutathione synthesis, but promotes CD36 mediated lipid uptake due to dysregulated cystine/glutamate exchange. Moreover, enforced expression of glutamate-cysteine ligase catalytic subunit (Gclc) promotes glutathione synthesis and prevents CD36 upregulation, thus boosting T cell anti-tumor immunity. Our findings reveal cystine as an intracellular metabolic checkpoint that orchestrates T-cell survival and differentiation, and highlight Gclc as a potential therapeutic target for enhancing T cell anti-tumor function.

DOI: https://doi.org/10.1038/s41419-024-06503-1
ACS Med Chem Lett. 2024 Feb 08. 15(2): 294-301

Design of Novel 18F-Labeled Amino Acid Tracers Using Sulfur 18F-Fluoride Exchange Click Chemistry.

Yong Huang, Hualong Chen, Lu Zhang, Yi Xie, Chengze Li, Ziyue Yu, Zeng Jiang, Wei Zheng, Zhongjing Li, Xuan Ge, Ying Liang, Zehui Wu.

[18F]Gln-OSO2F, [18F]Arg-OSO2F, and [18F]FSY-OSO2F were designed by introducing sulfonyl 18F-fluoride onto glutamine, arginine, and tyrosine, respectively. [18F]FSY-OSO2F can be prepared directly by sulfur 18F-fluoride exchange, while [18F]Gln-OSO2F and [18F]Arg-OSO2F require a two-step labeling method. Those tracers retain their typical transport characteristics for unmodified amino acids. Both PET imaging and biodistribution confirmed that [18F]FSY-OSO2F visualized MCF-7 and 22Rv1 subcutaneous tumors with high contrast, and its tumor-to-muscle ratio was better than that of [18F]FET. However, [18F]Gln-OSO2F and [18F]Arg-OSO2F poorly image MCF-7 subcutaneous tumors, possibly due to differences in the types and amounts of transporters expressed in tumors. All three tracers can visualize the U87MG glioma. According to our biological evaluation, none of the tracers evaluated in this study exhibited obvious defluorination, and subtle structural changes led to different imaging characteristics, indicating that the application of sulfur 18F-fluoride exchange click chemistry in the design of radioactive sulfonyl fluoride amino acids is feasible and offers significant advantages.

DOI: https://doi.org/10.1021/acsmedchemlett.3c00557
J Cancer. 2024 ;15(5): 1299-1313

New plasma diagnostic markers for colorectal cancer: transporter fragments of glutamate tRNA origin.

Changda Ye, Fu Cheng, Luji Huang, Kang Wang, Lin Zhong, Yan Lu, Manzhao Ouyang.

  Colorectal cancer (CRC) is the second leading cause of cancer-related deaths worldwide. Early diagnosis of the disease can greatly improve the clinical prognosis for patients with CRC. Unfortunately, there are no current simple and effective early diagnostic markers available. The transfer RNA (tRNA)-derived RNA fragments (tRFs) are a class of small non-coding RNAs (sncRNAs), which have been shown to play an important role in the development and prognosis of CRC. However, only a few studies on tRFs as early diagnostic markers in CRC have been conducted. In this study, previously ignored tRFs expression data were extracted from six paired small RNA sequencing data in the Sequence Read Archive (SRA) database using MINTmap. Three i-tRFs, derived from the tRNA that transports glutamate (i-tRF-Glu), were identified and used to construct a random forest diagnostic model. The model performance was evaluated using the receiver operating characteristic (ROC) curve and precision-recall (PR) curve. The area under the curves (AUC) for the ROC and PR was 0.941 and 0.944, respectively. We further verified the differences in expression of the these i-tRF-Glu in the tissue and plasma of both CRC patients and healthy subjects using quantitative real-time PCR (qRT-PCR). We found that the ROC-AUC of the three was greater than traditional plasma tumor markers such as CEA and CA199. Our bioinformatics analysis suggested that the these i-tRF-Glu are associated with cancer development and glutamate (Glu)-glutamine (Gln) metabolism. Overall, our study uncovered these i-tRF-Glu that have early diagnostic significance and therapeutic potential for CRC, this warrants further investigation into the diagnostic and therapeutic potential of these i-tRF-Glu in CRC.

Keywords:  colorectal cancer; glutamate metabolism; i-tRF; liquid biopsy; tRNA-derived fragments

DOI:  https://doi.org/10.7150/jca.92102
Sci Rep. 2024 Feb 15. 14(1): 3809

Silver nanoparticle functionalized by glutamine and conjugated with thiosemicarbazide induces apoptosis in colon cancer cell line.

Hadi Taati, Helia Sangani, Arash Davoudi, Samira Safabakhsh Kouchesfahani, Mohammad Hedayati, Sana Tarashandeh Hemmati, Taraneh Ghasemipour, Shahrzad Aghajani, Mahan Farah Andooz, Maryam Amanollahi, Fakhrieh Kalavari, Ali Salehzadeh.

  The high mortality rate of colon cancer indicates the insufficient efficacy of current chemotherapy. Thus, the discussion on engineered metal nanoparticles in the treatment of the disease has been considered. In this study, silver nanoparticles were functionalized with glutamine and conjugated with thiosemiccarbazide. Then, anticancer mechanism of Ag@Gln-TSC NPs in a colon cancer cell line (SW480) was investigated. Characterizing Ag@Gln-TSC NPs by FT-IR, XRD, EDS-mapping, DLS, zeta potential, and SEM and TEM microscopy revealed that the Ag@Gln-TSC NPs were correctly synthesized, the particles were spherical, with surface charge of - 27.3 mV, high thermal stability and low agglomeration level. Using MTT assay we found that Ag@Gln-TSC NPs were significantly more toxic for colon cancer cells than normal fibroblast cells with IC50 of 88 and 186 µg/mL, respectively. Flow cytometry analysis showed that treating colon cancer cells with Ag@Gln-TSC NPs leads to a considerable increase in the frequency of apoptotic cells (85.9% of the cells) and increased cell cycle arrest at the S phase. Also, several apoptotic features, including hyperactivity of caspase-3 (5.15 folds), increased expression of CASP8 gene (3.8 folds), and apoptotic nuclear alterations were noticed in the nanoparticle treated cells. Furthermore, treating colon cancer cells with Ag@Gln-TSC NPs caused significant down-regulation of the HULC Lnc-RNA and PPFIA4 oncogene by 0.3 and 0.6 folds, respectively. Overall, this work showed that Ag@Gln-TSC NPs can effectively inhibit colon cancer cells through the activation of apoptotic pathways, a feature that can be considered more in studies in the field of colon cancer treatment.

Keywords:  Apoptosis; Colon cancer; Flow cytometry; Silver nanoparticles; Thiosemicarbazide

DOI:  https://doi.org/10.1038/s41598-024-54344-x
Biomol Biomed. 2024 Feb 09.

Nuclear factor erythroid 2-related factor 2 promotes radioresistance by regulating glutamate-cysteine ligase modifier subunit and its unique immunoinvasive pattern.

Zhaoyuan Xue, Yiliyaer Nuerrula, Yilidana Sitiwaerdi, Mayinur Eli.

The enzyme glutamate-cysteine ligase modifier subunit (GCLM) serves as the initial rate-limiting factor in glutathione (GSH) synthesis. GSH is the preferred substrate for glutathione peroxidase 4 (GPX4), directly impacting its activity and stability. This study aims to elucidate the expression of GCLM and its correlation with the nuclear factor erythroid 2-related factor 2 (NFE2L2), commonly referred to as NRF2, in esophageal squamous cell carcinoma (ESCC) and further investigate the potential signaling axis of radiotherapy resistance caused by NRF2-mediated regulation of ferroptosis in ESCC. The expression of NRF2, GCLM, and GPX4 in ESCC was analyzed by bioinformatics, and their relationship with ferroptosis was verified through cell function experiments. Their role in radioresistance was then investigated through multiple validation steps. Bioinformatics analysis was employed to determine the immune infiltration pattern of NRF2 in ESCC. Furthermore, the effect of NRF2-mediated massive macrophage M2 infiltration on radiotherapy and ferroptosis was validated through in vivo experiments. In vitro assays demonstrated that overactivated NRF2 promotes radioresistance by directly binding to the promoter region of GCLM. The Tumor Immune Estimation Resource (TIMER) and quanTIseq analyses revealed NRF2 enrichment in M2 macrophages with a positive correlation. Co-culturing KYSE450 cells with M2 macrophages demonstrated that a significant infiltration of macrophages M2 can render ESCC cells resistant to radiotherapy but restore their sensitivity to ferroptosis in the process. Our study elucidates a link between the NRF2-GCLM-GSH-GPX4 signaling axis in ESCC, highlighting its potential as a therapeutic target for antagonistic biomarkers of resistance in the future. Additionally, it provides a novel treatment avenue for ESCC metastasis and radioresistance.

DOI: https://doi.org/10.17305/bb.2024.10184