bims-pimaco 2022-08-14 papers

on PI3K and MAPK signalling in colorectal cancer

Issue of 2022–08–14
eleven papers selected by
Lucas B. Zeiger, CRUK Scotland Institute, Beatson Institute for Cancer Research

Heterogeneity in RAS mutations: One size does not fit all.
MYC sensitises cells to apoptosis by driving energetic demand.
PTEN Dual Lipid- and Protein-Phosphatase Function in Tumor Progression.
Functional and biological heterogeneity of KRASQ61 mutations.
Characterization of KRAS Mutational Regression in Oligometastatic Patients.
mTORC1 controls Golgi architecture and vesicle secretion by phosphorylation of SCYL1.
Crosstalk between PI3K/Akt and Wnt/β-catenin pathways promote colorectal cancer progression regardless of mutational status.
PTEN inhibits AMPK to control collective migration.
The Role of PTEN in Epithelial-Mesenchymal Transition.
Impact of AKT1 polymorphism on DNA damage, BTG2 expression, and risk of colorectal cancer development.
Truncated FGFR2 is a clinically actionable oncogene in multiple cancers.

Sci Signal. 2022 Aug 09. 15(746): eadc9816

Heterogeneity in RAS mutations: One size does not fit all.

Nancy E Sealover, Robert L Kortum.

Although oncogenic driver mutations in RAS occur in 20% of cancers, heterogeneity in the biologic outputs of different RAS mutants has hampered efforts to develop effective treatments for RAS-mutated cancers. In this issue of Science Signaling, Huynh et al. show that even among KRASQ61 mutants, the specific amino acid that is substituted substantially affects mutant KRAS biologic activity and oncogenicity.

DOI: https://doi.org/10.1126/scisignal.adc9816
Nat Commun. 2022 Aug 09. 13(1): 4674

MYC sensitises cells to apoptosis by driving energetic demand.

Joy Edwards-Hicks, Huizhong Su, Maurizio Mangolini, Kubra K Yoneten, Jimi Wills, Giovanny Rodriguez-Blanco, Christine Young, Kevin Cho, Heather Barker, Morwenna Muir, Ania Naila Guerrieri, Xue-Feng Li, Rachel White, Piotr Manasterski, Elena Mandrou, Karen Wills, Jingyu Chen, Emily Abraham, Kianoosh Sateri, Bin-Zhi Qian, Peter Bankhead, Mark Arends, Noor Gammoh, Alex von Kriegsheim, Gary J Patti, Andrew H Sims, Juan Carlos Acosta, Valerie Brunton, Kamil R Kranc, Maria Christophorou, Erika L Pearce, Ingo Ringshausen, Andrew J Finch.

The MYC oncogene is a potent driver of growth and proliferation but also sensitises cells to apoptosis, which limits its oncogenic potential. MYC induces several biosynthetic programmes and primary cells overexpressing MYC are highly sensitive to glutamine withdrawal suggesting that MYC-induced sensitisation to apoptosis may be due to imbalance of metabolic/energetic supply and demand. Here we show that MYC elevates global transcription and translation, even in the absence of glutamine, revealing metabolic demand without corresponding supply. Glutamine withdrawal from MRC-5 fibroblasts depletes key tricarboxylic acid (TCA) cycle metabolites and, in combination with MYC activation, leads to AMP accumulation and nucleotide catabolism indicative of energetic stress. Further analyses reveal that glutamine supports viability through TCA cycle energetics rather than asparagine biosynthesis and that TCA cycle inhibition confers tumour suppression on MYC-driven lymphoma in vivo. In summary, glutamine supports the viability of MYC-overexpressing cells through an energetic rather than a biosynthetic mechanism.

DOI: https://doi.org/10.1038/s41467-022-32368-z
Cancers (Basel). 2022 Jul 28. pii: 3666. [Epub ahead of print]14(15):

PTEN Dual Lipid- and Protein-Phosphatase Function in Tumor Progression.

Anne Liu, Yanyu Zhu, Weiping Chen, Glenn Merlino, Yanlin Yu.

  PTEN is the second most highly mutated tumor suppressor in cancer, following only p53. The PTEN protein functions as a phosphatase with lipid- and protein-phosphatase activity. PTEN-lipid-phosphatase activity dephosphorylates PIP3 to form PIP2, and it then antagonizes PI3K and blocks the activation of AKT, while its protein-phosphatase activity dephosphorylates different protein substrates and plays various roles in tumorigenesis. Here, we review the PTEN mutations and protein-phosphatase substrates in tumorigenesis and metastasis. Our purpose is to clarify how PTEN protein phosphatase contributes to its tumor-suppressive functions through PI3K-independent activities.

Keywords:  PTEN; PTEN lipid phosphatase; PTEN protein phosphatase; PTEN protein substrate; metastasis; mutation; tumorigenesis

DOI:  https://doi.org/10.3390/cancers14153666
Sci Signal. 2022 Aug 09. 15(746): eabn2694

Functional and biological heterogeneity of KRASQ61 mutations.

Minh V Huynh, G Aaron Hobbs, Antje Schaefer, Mariaelena Pierobon, Leiah M Carey, J Nathaniel Diehl, Jonathan M DeLiberty, Ryan D Thurman, Adelaide R Cooke, Craig M Goodwin, Joshua H Cook, Lin Lin, Andrew M Waters, Naim U Rashid, Emanuel F Petricoin, Sharon L Campbell, Kevin M Haigis, Diane M Simeone, Costas A Lyssiotis, Adrienne D Cox, Channing J Der.

Missense mutations at the three hotspots in the guanosine triphosphatase (GTPase) RAS-Gly12, Gly13, and Gln61 (commonly known as G12, G13, and Q61, respectively)-occur differentially among the three RAS isoforms. Q61 mutations in KRAS are infrequent and differ markedly in occurrence. Q61H is the predominant mutant (at 57%), followed by Q61R/L/K (collectively 40%), and Q61P and Q61E are the rarest (2 and 1%, respectively). Probability analysis suggested that mutational susceptibility to different DNA base changes cannot account for this distribution. Therefore, we investigated whether these frequencies might be explained by differences in the biochemical, structural, and biological properties of KRASQ61 mutants. Expression of KRASQ61 mutants in NIH 3T3 fibroblasts and RIE-1 epithelial cells caused various alterations in morphology, growth transformation, effector signaling, and metabolism. The relatively rare KRASQ61E mutant stimulated actin stress fiber formation, a phenotype distinct from that of KRASQ61H/R/L/P, which disrupted actin cytoskeletal organization. The crystal structure of KRASQ61E was unexpectedly similar to that of wild-type KRAS, a potential basis for its weak oncogenicity. KRASQ61H/L/R-mutant pancreatic ductal adenocarcinoma (PDAC) cell lines exhibited KRAS-dependent growth and, as observed with KRASG12-mutant PDAC, were susceptible to concurrent inhibition of ERK-MAPK signaling and of autophagy. Our results uncover phenotypic heterogeneity among KRASQ61 mutants and support the potential utility of therapeutic strategies that target KRASQ61 mutant-specific signaling and cellular output.

DOI: https://doi.org/10.1126/scisignal.abn2694
Front Immunol. 2022 ;13 898561

Characterization of KRAS Mutational Regression in Oligometastatic Patients.

Alessandro Ottaiano, Roberta Penta de Vera d'Aragona, Anna Maria Trotta, Mariachiara Santorsola, Maria Napolitano, Giosuè Scognamiglio, Fabiana Tatangelo, Paolo Grieco, Silvia Zappavigna, Vincenza Granata, Francesco Perri, Amalia Luce, Giovanni Savarese, Monica Ianniello, Marika Casillo, Nadia Petrillo, Andrea Belli, Francesco Izzo, Guglielmo Nasti, Michele Caraglia, Stefania Scala.

   Background: We previously reported rare regressive genetic trajectories of KRAS pathogenic mutations as a specific hallmark of the genuine oligometastatic status in colorectal cancer (CRC).
Methods: Survival and prognostic impact of disease extent in 140 metastatic CRC patients were evaluated through the Kaplan-Meyer curves and the Log-Rank test. KRAS mutations were assessed through the Illumina NovaSeq 6000 platform and TruSight™ Oncology 500 kit. HLA typing was carried out by PCR with sequence-specific oligonucleotides. Lymphocyte densities in tumors were expressed as cells per square millimeter. NKs isolated and CD8+ from NK-depleted PBMCs were characterized through flow cytometry. CD107a externalization was evaluated as NKs/CD8 cytotoxicity toward human colon cancer cells HT29, SW620, HCT116, and LS174T carrying different KRAS mutations.
Results: The oligometastatic status was a strong and independent variable for survival (HR: 0.08 vs. polymetastatic disease; 95% CI: 0.02-0.26; p < 0.001). Eighteen oligometastatic patients were selected. Twelve were alive at the last follow-up, and 9 were characterized. Genetic regression of KRAS was observed in 3 patients: patient (PAT)2, PAT5, and PAT8. PAT2 and PAT5 presented the highest levels of GrzB+ lymphocytes in the tumor cores of the metastases (120 ± 11.2 and 132 ± 12.2 cells/mm2, respectively). Six out of 9 patients (67%), including PAT2 and PAT5, expressed HLA-C7. Twopatients (PAT2 and PAT5) presented high CD3+/CD8+-dependent cytotoxicity against HLA-C7+ SW620 cells (p.G12V-mutated cells), which was consistent with their observed mutational regression (p.G12V/p.G13D in primary→p.G13D in metastatic tumor).
Conclusions: We provide evidence that CD3+/CD8+ lymphocytes from oligometastatic CRC patients display differential cytotoxicity against human colon cancer cells carrying KRAS mutations. This could provide an interesting basis for monitoring oligometastatic disease and developing future adoptive immunotherapies.

Keywords:  HLA; KRAS; colorectal cancer; cytotoxicity; oligo-metastatic disease

DOI:  https://doi.org/10.3389/fimmu.2022.898561
Nat Commun. 2022 Aug 10. 13(1): 4685

mTORC1 controls Golgi architecture and vesicle secretion by phosphorylation of SCYL1.

Stéphanie Kaeser-Pebernard, Christine Vionnet, Muriel Mari, Devanarayanan Siva Sankar, Zehan Hu, Carole Roubaty, Esther Martínez-Martínez, Huiyuan Zhao, Miguel Spuch-Calvar, Alke Petri-Fink, Gregor Rainer, Florian Steinberg, Fulvio Reggiori, Jörn Dengjel.

The protein kinase mechanistic target of rapamycin complex 1 (mTORC1) is a master regulator of cell growth and proliferation, supporting anabolic reactions and inhibiting catabolic pathways like autophagy. Its hyperactivation is a frequent event in cancer promoting tumor cell proliferation. Several intracellular membrane-associated mTORC1 pools have been identified, linking its function to distinct subcellular localizations. Here, we characterize the N-terminal kinase-like protein SCYL1 as a Golgi-localized target through which mTORC1 controls organelle distribution and extracellular vesicle secretion in breast cancer cells. Under growth conditions, SCYL1 is phosphorylated by mTORC1 on Ser754, supporting Golgi localization. Upon mTORC1 inhibition, Ser754 dephosphorylation leads to SCYL1 displacement to endosomes. Peripheral, dephosphorylated SCYL1 causes Golgi enlargement, redistribution of early and late endosomes and increased extracellular vesicle release. Thus, the mTORC1-controlled phosphorylation status of SCYL1 is an important determinant regulating subcellular distribution and function of endolysosomal compartments. It may also explain the pathophysiology underlying human genetic diseases such as CALFAN syndrome, which is caused by loss-of-function of SCYL1.

DOI: https://doi.org/10.1038/s41467-022-32487-7
Cancer Biol Ther. 2022 Dec 31. 23(1): 1-13

Crosstalk between PI3K/Akt and Wnt/β-catenin pathways promote colorectal cancer progression regardless of mutational status.

Cassio Dejair Fleming-de-Moraes, Murilo Ramos Rocha, Josiane Weber Tessmann, Wallace Martins de Araujo, Jose Andres Morgado-Diaz.

  The PI3K/Akt and Wnt/β-catenin pathways play an important role in the acquisition of the malignant phenotype in cancer. However, there are few data regarding the role of the interplay between both pathways in colorectal cancer (CRC) progression. The mutational status and the clinicopathological characteristics of PI3K/Akt and Wnt/β-catenin pathways were accessed by bioinformatic analysis whereas that the impact of the interplay between the activity of both pathways to explain tumorigenic potential was performed in vitro using IGF-1 and Wnt3a treatments in CRC cell models. The mutational status of these pathways did not influence the survival of CRC patients, but an association between clinicopathological characteristics in patients with mutations in one, but not in both pathways was observed. A potentiating effect on the activation of both pathways and enhanced cellular migration and proliferation was observed when both pathways were activated simultaneously with IGF-1 and Wnt3a. In addition, these effects were hindered after pretreatment with LY294002, a specific PI3K inhibitor, suggesting some dependence between these two signaling cascades. Our findings show that, regardless of mutational status, there is an interplay between the activity of PI3K/Akt and Wnt/β-catenin pathways that contributes to events related to CRC progression and that the reversal of such events using a PI3K inhibitor highlights the value of targeting these pathways for potential directed therapies in CRC patients.

Keywords:  Akt; PI3K; Wnt; cell signaling; colorectal cancer; β-catenin

DOI:  https://doi.org/10.1080/15384047.2022.2108690
Nat Commun. 2022 Aug 11. 13(1): 4528

PTEN inhibits AMPK to control collective migration.

Florent Peglion, Lavinia Capuana, Isabelle Perfettini, Laurent Boucontet, Ben Braithwaite, Emma Colucci-Guyon, Emie Quissac, Karin Forsberg-Nilsson, Flora Llense, Sandrine Etienne-Manneville.

Pten is one of the most frequently mutated tumour suppressor gene in cancer. PTEN is generally altered in invasive cancers such as glioblastomas, but its function in collective cell migration and invasion is not fully characterised. Herein, we report that the loss of PTEN increases cell speed during collective migration of non-tumourous cells both in vitro and in vivo. We further show that loss of PTEN promotes LKB1-dependent phosphorylation and activation of the major metabolic regulator AMPK. In turn AMPK increases VASP phosphorylation, reduces VASP localisation at cell-cell junctions and decreases the interjunctional transverse actin arcs at the leading front, provoking a weakening of cell-cell contacts and increasing migration speed. Targeting AMPK activity not only slows down PTEN-depleted cells, it also limits PTEN-null glioblastoma cell invasion, opening new opportunities to treat glioblastoma lethal invasiveness.

DOI: https://doi.org/10.1038/s41467-022-31842-y
Cancers (Basel). 2022 Aug 03. pii: 3786. [Epub ahead of print]14(15):

The Role of PTEN in Epithelial-Mesenchymal Transition.

Olga Fedorova, Sergey Parfenyev, Alexandra Daks, Oleg Shuvalov, Nickolai A Barlev.

  Phosphatase and Tensin Homolog deleted on Chromosome 10 (PTEN) is one of the critical tumor suppressor genes and the main negative regulator of the PI3K pathway. PTEN is frequently found to be inactivated, either partially or fully, in various malignancies. The PI3K/AKT pathway is considered to be one of the main signaling cues that drives the proliferation of cells. Perhaps it is not surprising, then, that this pathway is hyperactivated in highly proliferative tumors. Importantly, the PI3K/AKT pathway also coordinates the epithelial-mesenchymal transition (EMT), which is pivotal for the initiation of metastases and hence is regarded as an attractive target for the treatment of metastatic cancer. It was shown that PTEN suppresses EMT, although the exact mechanism of this effect is still not fully understood. This review is an attempt to systematize the published information on the role of PTEN in the development of malignant tumors, with a main focus on the regulation of the PI3K/AKT pathway in EMT.

Keywords:  association of PTEN expression and EMT; lncRNAs and PTEN; molecular crosstalk between EMT-controlling transcription factors and PTEN; regulation of miRNAs; signaling networks of PTEN and EMT

DOI:  https://doi.org/10.3390/cancers14153786
Radiol Oncol. 2022 Aug 14. 56(3): 336-345

Impact of AKT1 polymorphism on DNA damage, BTG2 expression, and risk of colorectal cancer development.

Hina Zubair, Zahid Khan, Muhammad Imran.

   BACKGROUND: AKT, also called protein kinase B, is a serine-threonine kinase that functions as a mediator of PI3K-Akt-mTOR signaling pathway and plays an important role in an array of cellular processes. Many single nucleotide polymorphisms (SNP) in AKT gene have been observed to be associated with various types of cancers. In the current research the association of a functional SNP rs1130233 in AKT, depicting G to A transition, was studied with AKT activation, DNA damage, an early response B-cell translocation gene 2 (Btg2) expression and risk of colorectal cancer (CRC) development.
PATIENTS AND METHODS: A total 197 population-based controls and 200 CRC patients were genotyped for SNP rs1130233. AKT expression, activation and BTG2 expression were determined in GG, AG and AA genotype carriers. DNA damage was determined through comet assay.
RESULTS: The heterozygous AG genotype (55.67%) was more prevalent in the local population compared to homozygous wild type GG (37.78%) and homozygous AA genotypes (6.55%). Moreover, AG and AA alleles were observed to be significant contributors (P = 0.01, OR = 1.80, CI = 1.18 to 2.74, and P = 0.001, OR = 5.00, CI = 1.90 to 13.18, respectively) in increasing the risk of CRC. The immunoblot analysis revealed that G to A transition decreased the expression and activation of AKT. Moreover, AG and AA genotypes of AKT1 rs1130233 showed a significant increase in DNA damage and Btg2 expression.
CONCLUSIONS: The data concludes that G to A substitution is a risk factor for CRC development involving a decrease in AKT expression and activation and increase in DNA damage.

Keywords:  AKT1; BTG2; DNA damage; colorectal cancer; rs1130233

DOI:  https://doi.org/10.2478/raon-2022-0031
Nature. 2022 Aug 10.

Truncated FGFR2 is a clinically actionable oncogene in multiple cancers.

Daniel Zingg, Jinhyuk Bhin, Julia Yemelyanenko, Sjors M Kas, Frank Rolfs, Catrin Lutz, Jessica K Lee, Sjoerd Klarenbeek, Ian M Silverman, Stefano Annunziato, Chang S Chan, Sander R Piersma, Timo Eijkman, Madelon Badoux, Ewa Gogola, Bjørn Siteur, Justin Sprengers, Bim de Klein, Richard R de Goeij-de Haas, Gregory M Riedlinger, Hua Ke, Russell Madison, Anne Paulien Drenth, Eline van der Burg, Eva Schut, Linda Henneman, Martine H van Miltenburg, Natalie Proost, Huiling Zhen, Ellen Wientjens, Roebi de Bruijn, Julian R de Ruiter, Ute Boon, Renske de Korte-Grimmerink, Bastiaan van Gerwen, Luis Féliz, Ghassan K Abou-Alfa, Jeffrey S Ross, Marieke van de Ven, Sven Rottenberg, Edwin Cuppen, Anne Vaslin Chessex, Siraj M Ali, Timothy C Burn, Connie R Jimenez, Shridar Ganesan, Lodewyk F A Wessels, Jos Jonkers.

Somatic hotspot mutations and structural amplifications and fusions that affect fibroblast growth factor receptor 2 (encoded by FGFR2) occur in multiple types of cancer1. However, clinical responses to FGFR inhibitors have remained variable1-9, emphasizing the need to better understand which FGFR2 alterations are oncogenic and therapeutically targetable. Here we apply transposon-based screening10,11 and tumour modelling in mice12,13, and find that the truncation of exon 18 (E18) of Fgfr2 is a potent driver mutation. Human oncogenomic datasets revealed a diverse set of FGFR2 alterations, including rearrangements, E1-E17 partial amplifications, and E18 nonsense and frameshift mutations, each causing the transcription of E18-truncated FGFR2 (FGFR2ΔE18). Functional in vitro and in vivo examination of a compendium of FGFR2ΔE18 and full-length variants pinpointed FGFR2-E18 truncation as single-driver alteration in cancer. By contrast, the oncogenic competence of FGFR2 full-length amplifications depended on a distinct landscape of cooperating driver genes. This suggests that genomic alterations that generate stable FGFR2ΔE18 variants are actionable therapeutic targets, which we confirmed in preclinical mouse and human tumour models, and in a clinical trial. We propose that cancers containing any FGFR2 variant with a truncated E18 should be considered for FGFR-targeted therapies.

DOI: https://doi.org/10.1038/s41586-022-05066-5