Project description:Hepsin, a type II transmembrane serine protease, is commonly overexpressed in prostate and breast cancer. The hepsin protein is stabilized by the Ras-MAPK pathway, and downstream, this protease regulates the degradation of extracellular matrix components and activates growth factor pathways, such as hepatocyte growth factor and transforming growth factor beta (TGFβ) pathway. However, how exactly active hepsin promotes cell proliferation machinery to sustain tumor growth is not fully understood. Here, we show that genetic deletion of Hpn in a WAP-Myc model of aggressive MYC-driven breast cancer inhibits tumor growth in the primary syngrafted sites and the growth of disseminated tumors in the lungs. The suppression of tumor growth upon loss of hepsin was accompanied by downregulation of TGFβ and EGFR signaling together with a reduction in EGFR protein levels. We further demonstrate in 3D cultures of patient-derived breast cancer explants that neutralizing antibodies and small-molecule inhibitors of hepsin can be used to mitigate the hepsin-induced TGFβ signaling and reduce EGFR protein levels.The study demonstrates a role for hepsin as a regulator of cell proliferation and tumor growth through TGFβ and EGFR pathways, warranting consideration of hepsin as a potential indirect upstream target for therapeutic inhibition of TGFβ and EGFR pathways in cancer.
Project description:As a Class II small leucine-rich proteoglycan, fibromodulin (FMOD) plays critical roles in collagen fibrillogenesis and angiogenesis. However, the biological function of FMOD in oral squamous cell carcinoma remains unknown to date. In this study, immunohistochemistry and immunofluorescence assays identified that FMOD protein was located in cytoplasm and nucleus and was overexpressed in OSCC tissues and cell lines. Clinical analysis confirmed that FMOD overexpression showed a significant association with malignant progression (P=0.011) and lymph node metastasis (P=0.032) in OSCC patients. Moreover, loss-of-function studies verified that knockdown of FMOD significantly inhibited OSCC growth and metastasis in vitro and in vivo. Mechanismly, RNA sequencing studies further confirmed that. Knockdown of FMOD expression inhibited OSCC cell proliferation, migration, invasion, and tumor growth probably through altering transcriptome leading to active cell cycle, down-regulating Cell adhesion molecules and ECM-receptor interaction and through inhibiting EGFR-ERK and EGFR-AKT pathways.
Project description:Non-alcoholic steatohepatitis (NASH) has become a serious public health problem associated with metabolic syndrome. The mechanisms by which NASH induces hepatocellular carcinoma (HCC) remain unknown. There are no approved drugs for treating NASH or preventing NASH-induced HCC. We used a genetic mouse model in which HCC was induced via high-fat diet feeding. This mouse model strongly resembles human NASH-induced HCC. The natural product honokiol (HNK) was tested for its preventative effects against NASH progression to HCC. Then, to clarify the mechanisms underlying HCC development, human HCC cells were treated with HNK. We found that epidermal growth factor receptor (EGFR) signaling was hyperactivated in the livers of mice with NASH. Inhibition of EGFR signaling by HNK drastically attenuated HCC development in the mouse model. Mechanistically, HNK accelerated the nuclear translocation of glucocorticoid receptor (GR) and promoted mitogen-inducible gene 6 (MIG6)/ERBB receptor feedback inhibitor 1 (ERRFI1) expression, leading to EGFR degradation and thereby resulting in robust tumor suppression. EGFR degradation or inactivation represents a novel approach for NASH–HCC treatment and prevention, and the GR–MIG6 axis is a newly defined target that can be activated by HNK and related compounds.
Project description:The onset of secondary resistance represents a major limitation to long term efficacy of target therapies in cancer patients. Thus, the identification of mechanisms mediating secondary resistance is key to the rational design of alternative therapeutic strategies for resistant patients. MiRNA profiling combined with RNA-seq in MET-addicted gastric and lung cancer cell lines led us to identify the miR-205/ERRFI1 (ERBB receptor feedback inhibitor-1) axis as a novel mediator of resistance to MET tyrosine kinase inhibitors (TKIs). In cells resistant to MET-TKIs, increased miR-205 expression determined the downregulation of the EGFR inhibitor ERRFI1, which, in turn, caused EGFR activation and MET-TKI resistance. MiR-205/ERRFI1 driven EGFR activation rendered MET-TKI resistant cells sensitive to combined MET/EGFR inhibition. As a proof of concept of the clinical relevance of this newly identified mechanism of adaptive resistance, we report that a patient with a MET amplified lung adenocarcinoma displayed deregulation of the miR-205/ERRFI1 axis in concomitance with the onset of clinical resistance to anti-MET therapy.
Project description:Epidermal growth factor receptor (EGFR) signaling is constitutively activated in majority of GBM and is associated with a worse prognosis. Here we show that EGFR is responsible for overexpression of the m6A "reader" YTHDF2 in GBM through the EGFR/Src/ERK signaling pathway. YTHDF2 overexpression clinically correlates with poor glioma patient prognosis. EGFR signaling stabilizes YTHDF2 protein through phosphorylation of YTHDF2 serine 39 and threonine 381 by ERK1/2. YTHDF2 is required for GBM cell proliferation, invasion and tumorigenesis. YTHDF2 facilitates m6A-dependent mRNA decay of LXRA and HIVEP2, both are genes impacting glioma patient survival. YTHDF2 promotes tumorigenesis of GBM cells largely through downregulation of LXRA and HIVEP2. Further, YTHDF2 inhibits LXRA-dependent cholesterol homeostasis in GBM cells. Together, our findings extend the landscape of EGFR downstream circuit, uncover novel function for YTHDF2 in GBM tumorigenesis, and highlight an essential role of RNA m6A methylation in cholesterol homeostasis.
Project description:Epidermal growth factor receptor (EGFR) signaling is constitutively activated in majority of GBM and is associated with a worse prognosis. Here we show that EGFR is responsible for overexpression of the m6A "reader" YTHDF2 in GBM through the EGFR/Src/ERK signaling pathway. YTHDF2 overexpression clinically correlates with poor glioma patient prognosis. EGFR signaling stabilizes YTHDF2 protein through phosphorylation of YTHDF2 serine 39 and threonine 381 by ERK1/2. YTHDF2 is required for GBM cell proliferation, invasion and tumorigenesis. YTHDF2 facilitates m6A-dependent mRNA decay of LXRA and HIVEP2, both are genes impacting glioma patient survival. YTHDF2 promotes tumorigenesis of GBM cells largely through downregulation of LXRA and HIVEP2. Further, YTHDF2 inhibits LXRA-dependent cholesterol homeostasis in GBM cells. Together, our findings extend the landscape of EGFR downstream circuit, uncover novel function for YTHDF2 in GBM tumorigenesis, and highlight an essential role of RNA m6A methylation in cholesterol homeostasis.
Project description:Inhibitor of apoptosis (IAP) proteins constitute a conserved family of molecules which regulate both apoptosis and receptor signaling. They are often deregulated in cancer cells and represent potential targets for therapy. In our work, we investigated the effect of IAP inhibition in vivo to identify novel downstream genes expressed in an IAP-dependent manner that could contribute to cancer aggressiveness. To this end, immunocompromised mice engrafted subcutaneously with the triple negative breast cancer MDA-MB231 cell line were treated with SM83, a pan-IAP inhibitor developed by us, and tumor nodules were profiled for gene expression. Our work suggests that IAP-targeted therapy could contribute to EGFR inhibition and the reduction of its downstream mediators. This approach could be particularly effective in cells characterized by high levels of EGFR and Snai2, such as triple negative breast cancer.