Project description:Cdk4/6 inhibitors have shown to increase overall survival in hormone-positive breast tumors, but whether other solid tumors could respond to these inhibitors has not yet defined. Here we show that Palbociclib (a Cdk4/6 specific inhibitor in clinic use) + cisplatin (CDDP, a chemotherapeutic agent most active in locally or advanced bladder cancer patients) treatment exerts antiproliferative effects in vivo using a bladder cancer mouse model.
Project description:Cdk4/6 inhibitors have shown to increase overall survival in hormone-positive breast tumors, but whether other solid tumors could respond to these inhibitors has not yet defined. Here we show that Palbociclib (a Cdk4/6 specific inhibitor in clinic use) treatment exerts antiproliferative effects in vivo using a bladder cancer cell lines.
Project description:KRAS mutant pancreatic tumors have poor prognosis and few therapeutic options. Here, Frank et al. show that the combination of RMC4550 (SHP2 inhibitor) and LY3214996 (ERK inhibitor) effectively impairs tumor growth and induces tumor regression in multiplein vivo models of PDAC .
Project description:KRAS mutant pancreatic tumors have poor prognosis and few therapeutic options. Here, Frank et al. show that the combination of RMC4550 (SHP2 inhibitor) and LY3214996 (ERK inhibitor) effectively impairs tumor growth and induces tumor regression in multiplein vivo models of PDAC .
Project description:Numerous case studies have reported spontaneous regression of metastases following tumor excision, but underlying mechanisms are elusive. Here we present a model of metastases regression and latency elicited by the removal of a primary tumor, and identify underlying mechanisms. Human breast cancer cells, expressing highly sensitive luciferase, were implanted into the mammary fat-pad of mice, and the progression of early stage micrometastases, was monitored. Upon establishment of micrometastases, the primary tumor was excised, inducing a robust regression of metastatic signal, resulting in latent foci. In vivo supplementation of tumor secretome immediately upon tumor excision diminished this regression, implicating primary tumor secreted factors in promotion of metastatic growth. In vitro, cancer cell conditioned medium reduced apoptosis and enhanced adhesion of non-confluent cancer cells, and induced angiogenesis in endothelial cells. Cytokine array and proteomic analysis of cancer cells secretome identified 359 extracellular secreted factors, with significant enrichment of angiogenic factors, growth factors activity, focal adhesion, apoptosis, and metalloprotease processes. In vivo blockade of four key potential mediators of these processes, IL-8, PDGFaa, Serpin E1 (PAI-1), and MIF, arrested development of micrometastases. Moreover, high protein levels of these four factors were correlated with poor patient outcome. These results demonstrate regression and latency of metastases following tumor excision and a crucial role for primary tumor secretome in promoting early metastatic stages, suggesting novel mechanisms to control minimal residual disease.
Project description:Resistance to aromatase inhibitor (AI) treatment and combined CDK4/6 inhibitor (CDK4/6i) and endocrine therapy (ET) are crucial clinical challenges in treating estrogen receptor-positive (ER+) breast cancer. Understanding the resistance mechanisms and identifying reliable predictive biomarkers and novel treatment combinations to overcome resistance are urgently needed. Herein, we show that upregulation of CDK6, p-CDK2, and/or cyclin E1 is associated with adaptation and resistance to AI-monotherapy and combined CDK4/6i and ET in ER+ advanced breast cancer. Importantly, co-targeting CDK2 and CDK4/6 with ET synergistically impairs cellular growth, induces cell cycle arrest and apoptosis, and delays progression in AI-resistant and combined CDK4/6i and fulvestrant-resistant cell models and in an AI-resistant autocrine breast tumor in a postmenopausal xenograft model. Analysis of CDK6, p-CDK2, and/or cyclin E1 expression as a combined biomarker in metastatic lesions of ER+ advanced breast cancer patients treated with AI-monotherapy or combined CDK4/6i and ET revealed a correlation between high biomarker expression and shorter progression-free survival (PFS), and the biomarker combination was an independent prognostic factor in both patients cohorts. Our study supports the clinical development of therapeutic strategies co-targeting ER, CDK4/6 and CDK2 following progression on AI-monotherapy or combined CDK4/6i and ET to improve survival of patients exhibiting high tumor levels of CDK6, p-CDK2, and/or cyclin E1.
Project description:Background: Despite current therapeutic treatments including surgery, chemotherapy, radiotherapy and recently immunotherapy, the mortality rate of lung cancer stays high. Regarding lung cancer, epigenetic modifications altering cell cycle, angiogenesis and programmed cancer cell death are therapeutic targets to combine with immunotherapy to improve treatment success. In a recent study, we uncovered a dual function of a molecule called QAPHA ((E)-3-(5-((2-cyanoquinolin-4-yl)(methyl)amino)-2-methoxyphenyl)-N-hydroxyacrylamide) as both a tubulin polymerization and HDAC inhibitors. Here, we investigate the impact of this novel dual inhibitor on the lung cancer immune response. Methods: To elucidate the mechanism of action of QAPHA, we conducted a chemical proteomics analysis. Using an in vivo mouse model of lung cancer (TC-1 tumor cells), we assessed the effects of QAPHA on tumor regression. Tumor infiltrating immune cells were characterize by flow cytometry. Results In this study, we first show that QAPHA can inhibit HDAC6, leading to upregulation of HSP90, cytochrome C and caspases, found by proteomic analysis. We also confirm that QAPHA induces immunogenic cell death (ICD) by upregulating HMGB1 in vitro and demonstrated its effectiveness as a vaccine in vivo. Remarkably, even at a low concentration (0.5mg/kg), QAPHA achieved complete tumor regression in approximately 60% of intratumorally treated mice, establishing a long-lasting anticancer immune response. Moreover, QAPHA treatment promoted infiltration of neutrophils in the treated mice, reflecting inflammatory cell death promoted. Very interestingly, we show that QAPHA is also able to upregulate MHC-II expression on TC-1 tumor cells in vitro and in vivo. This process participates to the recruitment of CD4+ NKG2D+ CRTAM+ Perforin+ T cells in tumor infiltrate, defined as cytotoxic CD4+ T cells (CD4+ CTL). Finally, we show that tumor regression is strongly correlated to MHC-II expression level on tumor cell and CD4+ CTL infiltrate. Conclusion Collectively, our findings shed light on the discovery of a new multi-target inhibitor able to induce ICD and MHC-II upregulation in TC-1 tumor cell. These two processes participate to enhance a specific CD4+ cytotoxic T cell-mediated anti-tumor response in vivo in our model of lung cancer. This breakthrough suggests the potential of QAPHA as a promising therapeutic agent for cancer treatment.
Project description:The combination of RMC4550 (SHP2 inhibitor) and LY3214996 (ERK inhibitor) effectively impairs tumor growth and induces tumor regression in multiplein vivo models of PDAC
Project description:Cyclin-dependent kinase 4/6 (CDK4/6) inhibitors are approved for breast cancer treatment and show activity against other malignancies, including KRAS-mutant non-small cell lung cancer (NSCLC). However, the clinical efficacy of CDK4/6 inhibitors is limited due to frequent drug resistance and their largely cytostatic effects. Through a genome-wide cDNA screen, we identified that bromodomain-containing protein 4 (BRD4) overexpression conferred resistance to the CDK4/6 inhibitor palbociclib in KRAS-mutant NSCLC cells. Inhibition of BRD4, either by RNA interference or small-molecule inhibitors, synergized with palbociclib to induce senescence in NSCLC cells and tumors, and the combination prolonged survival in a KRAS-mutant NSCLC mouse model. Mechanistically, BRD4-inhibition enhanced cell cycle arrest and reactive oxygen species (ROS) accumulation, both of which are necessary for senescence induction; this in turn elevated GPX4, a peroxidase that suppresses ROS-triggered ferroptosis. Consequently, GPX4 inhibitor treatment selectively induced ferroptotic cell death in the senescent cancer cells, resulting in tumor regression. Co-targeting CDK4/6 and BRD4 also promoted senescence and ferroptosis vulnerability in pancreatic and breast cancer cells. Together, these findings reveal therapeutic vulnerabilities and effective combinations to enhance the clinical utility of CDK4/6 inhibitors.