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Radiology and Oncology Sep 2019Background Colorectal cancer is a successful model of genetic biomarker development in oncology. Currently, several predictive or prognostic genetic alterations have... (Review)
Review
Background Colorectal cancer is a successful model of genetic biomarker development in oncology. Currently, several predictive or prognostic genetic alterations have been identified and are used in clinical practice. The RAS gene family, which includes KRAS and NRAS act as predictors for anti-epithelial growth factor receptor treatment (anti-EGFR), and it has been suggested that NRAS mutations also play a role in prognosis: patients harboring NRAS alterations have a significantly shorter survival compared to those with wild type tumours. BRAF V600E mutations are rare and occur mostly in tumors located in the ascending colon in elderly female patients. BRAF is instrumental in establishing prognosis: survival is shorter by 10-16 months in BRAF-mutant patients, and BRAF may be a negative prognostic factor for patients who undergo hepatic or pulmonary metastasectomy. Moreover, this mutation is used as a negative predictive factor for anti-EGFR therapies. Two new biomarkers have recently been added to the metastatic colorectal cancer panel: HER2 and microsatellite instability. While HER2 is still being investigated in different prospective studies in order to validate its prognostic role, microsatellite instability already guides clinical decisions in substituted with advanced colorectal cancer. Conclusions There are current evidences that support using above mentioned genetic biomarkers to better identify the right medicine that is supposed to be used in the right patient. This approach contributes to a more individualized patient-oriented treatment in daily clinical practice.
Topics: Antineoplastic Agents, Immunological; Antineoplastic Combined Chemotherapy Protocols; Cetuximab; Colorectal Neoplasms; ErbB Receptors; Female; Genes, erbB-2; Genes, ras; Genetic Markers; Humans; Ipilimumab; Male; Microsatellite Instability; Mutation; Panitumumab; Prognosis; Proto-Oncogene Proteins B-raf; Sex Factors; Trastuzumab
PubMed: 31553708
DOI: 10.2478/raon-2019-0033 -
Cancer Cell Mar 2024KRAS inhibitors (adagrasib and sotorasib) have shown clinical promise in targeting KRAS-mutated lung cancers; however, most patients eventually develop resistance. In...
KRAS inhibitors (adagrasib and sotorasib) have shown clinical promise in targeting KRAS-mutated lung cancers; however, most patients eventually develop resistance. In lung patients with adenocarcinoma with KRAS and STK11/LKB1 co-mutations, we find an enrichment of the squamous cell carcinoma gene signature in pre-treatment biopsies correlates with a poor response to adagrasib. Studies of Lkb1-deficient KRAS and Kras lung cancer mouse models and organoids treated with KRAS inhibitors reveal tumors invoke a lineage plasticity program, adeno-to-squamous transition (AST), that enables resistance to KRAS inhibition. Transcriptomic and epigenomic analyses reveal ΔNp63 drives AST and modulates response to KRAS inhibition. We identify an intermediate high-plastic cell state marked by expression of an AST plasticity signature and Krt6a. Notably, expression of the AST plasticity signature and KRT6A at baseline correlates with poor adagrasib responses. These data indicate the role of AST in KRAS inhibitor resistance and provide predictive biomarkers for KRAS-targeted therapies in lung cancer.
Topics: Animals; Mice; Humans; Proto-Oncogene Proteins p21(ras); Lung Neoplasms; Genes, ras; Carcinoma, Squamous Cell; Mutation; Acetonitriles; Piperazines; Pyrimidines
PubMed: 38402609
DOI: 10.1016/j.ccell.2024.01.012 -
Gastroenterology Dec 2020The pattern of genetic alterations in cancer driver genes in patients with hepatocellular carcinoma (HCC) is highly diverse, which partially explains the low efficacy of...
BACKGROUND AND AIMS
The pattern of genetic alterations in cancer driver genes in patients with hepatocellular carcinoma (HCC) is highly diverse, which partially explains the low efficacy of available therapies. In spite of this, the existing mouse models only recapitulate a small portion of HCC inter-tumor heterogeneity, limiting the understanding of the disease and the nomination of personalized therapies. Here, we aimed at establishing a novel collection of HCC mouse models that captured human HCC diversity.
METHODS
By performing hydrodynamic tail-vein injections, we tested the impact of altering a well-established HCC oncogene (either MYC or β-catenin) in combination with an additional alteration in one of eleven other genes frequently mutated in HCC. Of the 23 unique pairs of genetic alterations that we interrogated, 9 were able to induce HCC. The established HCC mouse models were characterized at histopathological, immune, and transcriptomic level to identify the unique features of each model. Murine HCC cell lines were generated from each tumor model, characterized transcriptionally, and used to identify specific therapies that were validated in vivo.
RESULTS
Cooperation between pairs of driver genes produced HCCs with diverse histopathology, immune microenvironments, transcriptomes, and drug responses. Interestingly, MYC expression levels strongly influenced β-catenin activity, indicating that inter-tumor heterogeneity emerges not only from specific combinations of genetic alterations but also from the acquisition of expression-dependent phenotypes.
CONCLUSIONS
This novel collection of murine HCC models and corresponding cell lines establishes the role of driver genes in diverse contexts and enables mechanistic and translational studies.
Topics: Animals; Carcinoma, Hepatocellular; Cell Line, Tumor; Computational Biology; Disease Models, Animal; Drug Resistance, Neoplasm; Female; Gene Expression Regulation, Neoplastic; Genetic Heterogeneity; Humans; Liver Neoplasms; Male; Mice; Mice, Transgenic; Proto-Oncogenes; Tumor Escape; Tumor Microenvironment
PubMed: 32814112
DOI: 10.1053/j.gastro.2020.08.015 -
International Journal of Molecular... Dec 2023Neuroblastoma (NB), a childhood cancer arising from the neural crest, poses significant clinical challenges, particularly in cases featuring amplification of the... (Review)
Review
Neuroblastoma (NB), a childhood cancer arising from the neural crest, poses significant clinical challenges, particularly in cases featuring amplification of the oncogene. Epigenetic factors play a pivotal role in normal neural crest and NB development, influencing gene expression patterns critical for tumorigenesis. This review delves into the multifaceted interplay between MYCN and known epigenetic modifications during NB genesis, shedding light on the intricate regulatory networks underlying the disease. We provide an extensive survey of known epigenetic mechanisms, encompassing DNA methylation, histone modifications, non-coding RNAs, super-enhancers (SEs), bromodomains (BET), and chromatin modifiers in -amplified (MNA) NB. These epigenetic changes collectively contribute to the dysregulated gene expression landscape observed in MNA NB. Furthermore, we review emerging therapeutic strategies targeting epigenetic regulators, including histone deacetylase inhibitors (HDACi), histone methyltransferase inhibitors (HMTi), and DNA methyltransferase inhibitors (DNMTi). We also discuss and summarize current drugs in preclinical and clinical trials, offering insights into their potential for improving outcomes for MNA NB patients.
Topics: Humans; DNA Methylation; Epigenesis, Genetic; Gene Expression Regulation, Neoplastic; Genes, myc; N-Myc Proto-Oncogene Protein; Neuroblastoma
PubMed: 38069407
DOI: 10.3390/ijms242317085 -
Blood Mar 2023Upregulation of the proto-oncogene T-cell leukemia/lymphoma 1A (TCL1A) is causally implicated in various B-cell and T-cell malignancies. High-level TCL1A correlates with...
Upregulation of the proto-oncogene T-cell leukemia/lymphoma 1A (TCL1A) is causally implicated in various B-cell and T-cell malignancies. High-level TCL1A correlates with aggressive disease features and inferior clinical outcomes. However, the molecular and cell biological consequences of, particularly nuclear, TCL1A are not fully elucidated. We observed here in mouse models of subcellular site-specific TCL1A-induced lymphomagenesis that TCL1A exerts a strong transforming impact via nuclear topography. In proteomic screens of TCL1A-bound molecules in chronic lymphocytic leukemia (CLL) cells and B-cell lymphoma lines, we identified regulators of cell cycle and DNA repair pathways as novel TCL1A interactors, particularly enriched under induced DNA damage and mitosis. By functional mapping and in silico modeling, we specifically identified the mitotic checkpoint protein, cell division cycle 20 (CDC20), as a direct TCL1A interactor. According to the regulatory impact of TCL1A on the activity of the CDC20-containing mitotic checkpoint and anaphase-promoting complexes during mitotic progression, TCL1A overexpression accelerated cell cycle transition in B-cell lymphoma lines, impaired apoptotic damage responses in association with pronounced chromosome missegregation, and caused cellular aneuploidy in Eμ-TCL1A mice. Among hematopoietic cancers, CDC20 levels seem particularly low in CLL. CDC20 expression negatively correlated with TCL1A and lower expression marked more aggressive and genomically instable disease and cellular phenotypes. Knockdown of Cdc20 in TCL1A-initiated murine CLL promoted aneuploidy and leukemic acceleration. Taken together, we discovered a novel cell cycle-associated effect of TCL1A abrogating controlled cell cycle transition. This adds to our concept of oncogenic TCL1A by targeting genome stability. Overall, we propose that TCL1A acts as a pleiotropic adapter molecule with a synergistic net effect of multiple hijacked pathways.
Topics: Mice; Animals; Leukemia, Lymphocytic, Chronic, B-Cell; Proto-Oncogene Proteins; Proteomics; Lymphoma, B-Cell; Cell Cycle; Proto-Oncogenes; Cell Cycle Proteins; Mitosis
PubMed: 36179280
DOI: 10.1182/blood.2022015494 -
Nature Communications Aug 2023Whether TMPRSS2-ERG fusion and TP53 gene alteration coordinately promote prostate cancer (PCa) remains unclear. Here we demonstrate that TMPRSS2-ERG fusion and TP53...
Whether TMPRSS2-ERG fusion and TP53 gene alteration coordinately promote prostate cancer (PCa) remains unclear. Here we demonstrate that TMPRSS2-ERG fusion and TP53 mutation / deletion co-occur in PCa patient specimens and this co-occurrence accelerates prostatic oncogenesis. p53 gain-of-function (GOF) mutants are now shown to bind to a unique DNA sequence in the CTNNB1 gene promoter and transactivate its expression. ERG and β-Catenin co-occupy sites at pyrimidine synthesis gene (PSG) loci and promote PSG expression, pyrimidine synthesis and PCa growth. β-Catenin inhibition by small molecule inhibitors or oligonucleotide-based PROTAC suppresses TMPRSS2-ERG- and p53 mutant-positive PCa cell growth in vitro and in mice. Our study identifies a gene transactivation function of GOF mutant p53 and reveals β-Catenin as a transcriptional target gene of p53 GOF mutants and a driver and therapeutic target of TMPRSS2-ERG- and p53 GOF mutant-positive PCa.
Topics: Animals; Humans; Male; Mice; beta Catenin; Gain of Function Mutation; Oncogene Proteins, Fusion; Prostatic Neoplasms; Proto-Oncogenes; Pyrimidines; Transcriptional Regulator ERG; Tumor Suppressor Protein p53
PubMed: 37537199
DOI: 10.1038/s41467-023-40352-4 -
Cancer Metastasis Reviews Dec 2020One of the mechanisms potentially explaining the discrepancy between the number of human genes and the functional complexity of organisms is generating alternative... (Review)
Review
One of the mechanisms potentially explaining the discrepancy between the number of human genes and the functional complexity of organisms is generating alternative splice variants, an attribute of the vast majority of multi-exon genes. Members of the RAS family, such as NRAS, KRAS and HRAS, all of which are of significant importance in cancer biology, are no exception. The structural and functional differences of these splice variants, particularly if they contain the canonical (and therefore routinely targeted for diagnostic purposes) hot spot mutations, pose a significant challenge for targeted therapies. We must therefore consider whether these alternative splice variants constitute a minor component as originally thought and how therapies targeting the canonical isoforms affect these alternative splice variants and their overall functions.
Topics: Alternative Splicing; Amino Acid Sequence; Animals; Base Sequence; Genes, ras; Humans; Mutation; Neoplasms; Protein Processing, Post-Translational; Proto-Oncogene Proteins p21(ras); RNA, Messenger
PubMed: 32772213
DOI: 10.1007/s10555-020-09920-8 -
Oncogene May 2023KRAS, HRAS and NRAS proto-oncogenes belong to a family of 40 highly homologous genes, which in turn are a subset of a superfamily of >160 genes encoding small GTPases....
KRAS, HRAS and NRAS proto-oncogenes belong to a family of 40 highly homologous genes, which in turn are a subset of a superfamily of >160 genes encoding small GTPases. RAS proteins consist of a globular G-domain (aa1-166) and a 22-23 aa unstructured hypervariable region (HVR) that mediates membrane targeting. The evolutionary origins of the RAS isoforms, their HVRs and alternative splicing of the KRAS locus has not been explored. We found that KRAS is basal to the RAS proto-oncogene family and its duplication generated HRAS in the common ancestor of vertebrates. In a second round of duplication HRAS generated NRAS and KRAS generated an additional RAS gene we have designated KRASBL, absent in mammals and birds. KRAS4A arose through a duplication and insertion of the 4 exon of NRAS into the 3 intron of KRAS. We found evolutionary conservation of a short polybasic region (PBR1) in HRAS, NRAS and KRAS4A, a second polybasic region (PBR2) in KRAS4A, two neutralized basic residues (NB) and a serine in KRAS4B and KRASBL, and a modification of the CaaX motif in vertebrates with farnesyl rather than geranylgeranyl polyisoprene lipids, suggesting that a less hydrophobic membrane anchor is critical to RAS protein function. The persistence of four RAS isoforms through >400 million years of evolution argues strongly for differential function.
Topics: Animals; Humans; Proto-Oncogene Proteins p21(ras); Protein Isoforms; ras Proteins; Genes, ras; Mammals
PubMed: 37031342
DOI: 10.1038/s41388-023-02672-z -
Oncotarget Jul 2023Ras proteins are small GTPases that regulate cell growth and division. Mutations in Ras genes are associated with many types of cancer, making them attractive targets... (Review)
Review
Ras proteins are small GTPases that regulate cell growth and division. Mutations in Ras genes are associated with many types of cancer, making them attractive targets for cancer therapy. Despite extensive efforts, targeting Ras proteins with small molecules has been extremely challenging due to Ras's mostly flat surface and lack of small molecule-binding cavities. These challenges were recently overcome by the development of the first covalent small-molecule anti-Ras drug, sotorasib, highlighting the efficacy of Ras inhibition as a therapeutic strategy. However, this drug exclusively inhibits the Ras G12C mutant, which is not a prevalent mutation in most cancer types. Unlike the G12C variant, other Ras oncogenic mutants lack reactive cysteines, rendering them unsuitable for targeting via the same strategy. Protein engineering has emerged as a promising method to target Ras, as engineered proteins have the ability to recognize various surfaces with high affinity and specificity. Over the past few years, scientists have engineered antibodies, natural Ras effectors, and novel binding domains to bind to Ras and counteract its carcinogenic activities via a variety of strategies. These include inhibiting Ras-effector interactions, disrupting Ras dimerization, interrupting Ras nucleotide exchange, stimulating Ras interaction with tumor suppressor genes, and promoting Ras degradation. In parallel, significant advancements have been made in intracellular protein delivery, enabling the delivery of the engineered anti-Ras agents into the cellular cytoplasm. These advances offer a promising path for targeting Ras proteins and other challenging drug targets, opening up new opportunities for drug discovery and development.
Topics: Humans; Genes, ras; ras Proteins; Neoplasms; Mutation; Protein Engineering; Proto-Oncogene Proteins p21(ras)
PubMed: 37395750
DOI: 10.18632/oncotarget.28469 -
Blood Aug 2022Detailed genomic and epigenomic analyses of MECOM (the MDS1 and EVI1 complex locus) have revealed that inversion or translocation of chromosome 3 drives inv(3)/t(3;3)...
Detailed genomic and epigenomic analyses of MECOM (the MDS1 and EVI1 complex locus) have revealed that inversion or translocation of chromosome 3 drives inv(3)/t(3;3) myeloid leukemias via structural rearrangement of an enhancer that upregulates transcription of EVI1. Here, we identify a novel, previously unannotated oncogenic RNA-splicing derived isoform of EVI1 that is frequently present in inv(3)/t(3;3) acute myeloid leukemia (AML) and directly contributes to leukemic transformation. This EVI1 isoform is generated by oncogenic mutations in the core RNA splicing factor SF3B1, which is mutated in >30% of inv(3)/t(3;3) myeloid neoplasm patients and thereby represents the single most commonly cooccurring genomic alteration in inv(3)/t(3;3) patients. SF3B1 mutations are statistically uniquely enriched in inv(3)/t(3;3) myeloid neoplasm patients and patient-derived cell lines compared with other forms of AML and promote mis-splicing of EVI1 generating an in-frame insertion of 6 amino acids at the 3' end of the second zinc finger domain of EVI1. Expression of this EVI1 splice variant enhanced the self-renewal of hematopoietic stem cells, and introduction of mutant SF3B1 in mice bearing the humanized inv(3)(q21q26) allele resulted in generation of this novel EVI1 isoform in mice and hastened leukemogenesis in vivo. The mutant SF3B1 spliceosome depends upon an exonic splicing enhancer within EVI1 exon 13 to promote usage of a cryptic branch point and aberrant 3' splice site within intron 12 resulting in the generation of this isoform. These data provide a mechanistic basis for the frequent cooccurrence of SF3B1 mutations as well as new insights into the pathogenesis of myeloid leukemias harboring inv(3)/t(3;3).
Topics: Animals; Chromosome Inversion; Chromosomes, Human, Pair 3; DNA-Binding Proteins; Humans; Leukemia, Myeloid, Acute; MDS1 and EVI1 Complex Locus Protein; Mice; Proto-Oncogenes; Transcription Factors
PubMed: 35709354
DOI: 10.1182/blood.2021015325