Project description:cMET is a well known oncogene whose activation is widely implicated in tumorigenesis and metastasis. To investigate the effects of acute inhibitoin of cMET signaling in the mammary tumors, we inhibited cMET activation in xenograft mammary tumors that were derived from a MET amplified mouse mammary tumor cell line and analyzed the transcriptional alteration between vehicle and MET inhibitor treated tumors.
Project description:Baseline gene expression for two primary and two recurrent tumor cell lines derived from MTB;TAN transgenic mice. Microarrays were performed in biological duplicate to determine differential gene expression between primary and recurrent tumor cell cohorts.
Project description:Background Esophageal adenocarcinomas (EACs) represent an evolving tumor entity with high mortality rates. MET amplification is a recurrent driver in EACs and is associated with decreased patient survival. However, the response to MET inhibitors is limited. Recent studies have identified several mechanisms that lead to resistance against MET inhibitors in different tumor entities. Nonetheless, a characterization of additional vulnerable targets beyond MET has not been conducted in MET-amplified EACs. Methods In this study, we determined the MET amplification status in a cohort of more than 900 EACs using fluorescence in situ hybridization (FISH) and compared the proteomes of MET-amplified versus non-amplified tumors by mass spectrometry. Results We identified a phenotype, present in almost all MET-amplified tumors, which shows an enrichment of alternative RNA splicing, and androgen receptor signaling proteins, as well as decreased patient survival. Additionally, our analyses revealed a negative correlation between MET expression and patient survival in MET-amplified EACs, indicating biological heterogeneity with clinical relevance despite the presence of MET amplification as the predominant oncogenic driver. Furthermore, quantitative immunohistochemical analysis of the inflammatory tumor microenvironment showed that an increased percentage of M2 macrophages is associated with lower overall survival in MET-amplified EACs. Conclusions Our results provide valuable insights into possible new therapeutic approaches for MET-amplified EACs for further research.
Project description:Genome-wide expression data can provide important insights into normal and pathological cellular processes. However, the ability to use gene expression data to quantitatively assess the activation state of a given signaling pathway or transcriptional network in a sensitive and specific manner remains an important unmet goal. We now describe a computational algorithm, energy-paired scoring (EPS), that satisfies these criteria by predicting pathway activity using gene-gene interactions within a pathway signature in a manner analogous to the estimation of energy generated by two charged particles, as described by Coulomb’s law. We demonstrate the ability of EPS to: quantitatively assess pathway activation levels in vivo and in vitro; accurately estimate the extent of pathway inhibition achieved by gene knockdown; sensitively detect crosstalk between endogenous signaling pathways in vivo; and accurately identify compounds capable of inhibiting selected signaling pathways. Our findings indicate that EPS can accurately predict pathway activity over a wide dynamic range based upon gene expression data sets derived from multiple profiling platforms, as well as different species, tissues and cell types in both in vitro and in vivo contexts Four timepoints (0h, 24h, 48h and 96h) with 3 replicates per timepoint of doxycycline induction for MTB (Control), MTB/TAN, MTB/TOM and MTB/TWNT1
Project description:Receptor tyrosine kinases (RTKs) are recognized as targets of precision medicine in human cancer upon their gene amplification or constitutive activation, resulting in increased downstream signal complexity including heterotypic crosstalk with other RTKs. The Met hepatocyte growth factor RTK exhibits such reciprocal crosstalk with several members of the human EGFR (HER) family of RTKs when amplified in cancer cells. We observed that Met signaling converges on HER3 tyrosine phosphorylation across a panel of seven MET-amplified cancer cell lines and that HER3 is required for cancer cell expansion and oncogenic capacity in vitro and in vivo. In order to identify genes required for cancer cell proliferation in the MET-amplified setting whose expression, we stably transduced KatoII MET-amplified cells with shRNA targeting ERBB3, the gene encoding HER3. Stably-transduced cells were selected with puromycin, assayed for proliferative phenotype, and lysed for RNA extraction. Pooled libraries of total RNA were then sequenced using the Illumina HiSeq4000 platform, and differentially-expressed genes were identified from read counts normalized across samples. Differentially-expressed genes were further assayed for dependence on HER3 in other MET-amplified cell lines to identify genes recurrently dependent on HER3 in the MET-amplified setting.
Project description:MET amplification is present in 20% of gastric cancers and has been confirmed as a therapeutic target in clinical trials. The molecular mechanisms of response and resistance to MET inhibitors are not well understood. We investigated the determinants of MET dependency in human gastric cancer. MET inhibition inhibited proliferation and induced cell death only in MET-amplified gastric cancer cell lines. The effects on growth arrest were stronger than the effects on cell death. To identify possible resistance mechanisms, we performed whole-genome mRNA expression profiling. Molecular changes related to autophagy were among the top alterations observed. Consistent with these findings, autophagy levels increased in a concentration-dependent manner when MET-amplified cells were exposed to crizotinib. Autophagy inhibition caused a dramatic decrease in apoptosis in one of the MET-amplified cell lines (MKN45) but not in the other (SNU-5). Because autophagy may provide energy in cells subjected to growth factor deprivation, we explored the effects of MET or autophagy inhibition on cellular ATP levels. This revealed that autophagy-dependent ATP production was selectively required for apoptosis in the MKN45 cells and that chemical ATP depletion mimicked the effects of autophagy inhibition to block cell death. Overall, the data reveal a novel relationship between ATP depletion and resistance to MET inhibitor-induced cell death. Our observations suggest that autophagy inhibitors could have unintended consequences when they are combined with growth factor receptor inhibitors in tumors that require autophagy-dependent ATP production for apoptosis. 12 samples triplicate samples of SNU-5 and MKN45 +/- criztonib for 24 hours
Project description:cMET is a well known oncogene whose activation is widely implicated in tumorigenesis and metastasis. To investigate the effects of acute activation of cMET signaling in the mammary epithelial cells, we stimulated MCF10A cells with increasing doses of HGF and analyzed the transcriptional alteration between PBS and HGF treated cells.