Project description:Single-agent immunotherapy has achieved limited clinical benefit to date in patients with pancreatic ductal adenocarcinoma (PDAC). This may be a result of the presence of a uniquely immunosuppressive tumor microenvironment (TME). Critical obstacles to immunotherapy in PDAC tumors include a high number of tumor-associated immunosuppressive cells and a uniquely desmoplastic stroma that functions as a barrier to T cell infiltration. We identified hyperactivated focal adhesion kinase (FAK) activity in neoplastic PDAC cells as an important regulator of the fibrotic and immunosuppressive TME. We found that FAK activity was elevated in human PDAC tissues and correlated with high levels of fibrosis and poor CD8+ cytotoxic T cell infiltration. Single-agent FAK inhibition using the selective FAK inhibitor VS-4718 substantially limited tumor progression, resulting in a doubling of survival in the p48-Cre;LSL-KrasG12D;Trp53flox/+ (KPC) mouse model of human PDAC. This delay in tumor progression was associated with markedly reduced tumor fibrosis and decreased numbers of tumor-infiltrating immunosuppressive cells. We also found that FAK inhibition rendered the previously unresponsive KPC mouse model responsive to T cell immunotherapy and PD-1 antagonists. These data suggest that FAK inhibition increases immune surveillance by overcoming the fibrotic and immunosuppressive PDAC TME and renders tumors responsive to immunotherapy.
Project description:Cancers evade the immune system in order to grow or metastasise through the process of cancer immunoediting. While checkpoint inhibitor therapy has been effective for reactivating tumour immunity in some cancers, many solid cancers, including breast cancer, remain largely non-responsive. Understanding the way non-responsive cancers evolve to evade immunity, what resistance pathways are activated and whether this occurs at the clonal level will improve immunotherapeutic design. We tracked cancer cell clones during the immunoediting process and determined clonal transcriptional profiles that allow immune evasion in murine mammary tumour growth in response to immunotherapy with anti-PD1 and anti-CTLA4. Clonal diversity was significantly restricted by immunotherapy treatment at both the primary and metastatic sites. These findings demonstrate that immunoediting selects for pre-existing breast cancer cell populations, that immunoediting is not a static process and is ongoing during metastasis and immunotherapy treatment. Isolation of immunotherapy resistant clones revealed unique and overlapping transcriptional signatures. The overlapping gene signature was predictive of poor survival in basal-like breast cancer patient cohorts. Some of these overlapping genes have existing small molecules which can be used to potentially improve immunotherapy response.
Project description:Immunotherapeutics represent highly promising agents with the potential to improve patient outcomes in a variety of cancer types. Unfortunately, single-agent immunotherapy has achieved limited clinical benefit to date in patients suffering from pancreatic ductal adenocarcinoma (PDAC). This may be due to the presence of a uniquely immunosuppressive tumor microenvironment (TME) present in PDACs, which creates a barrier to effective immune surveillance. Critical obstacles to immunotherapy in PDAC tumors include the dense desmoplastic stroma that acts as a barrier to T-cell infiltration and the high numbers of tumor-associated immunosuppressive cells. We have identified hyperactivated focal adhesion kinase (FAK) activity in neoplastic PDAC cells as a significant regulator of the fibrotic and immunosuppressive TME. We found that FAK activity was elevated in human PDAC tissues and correlates with high levels of fibrosis and poor CD8+ cytotoxic T-cell infiltration. Single-agent FAK inhibition (VS-4718) dramatically limited tumor progression, resulting in a doubling of survival in the p48-Cre/LSL-KrasG12D/p53Flox/+ (KPC) mouse model of human PDAC. This alteration in tumor progression was associated with dramatically reduced tumor fibrosis, decreased numbers of tumor-infiltrating immature myeloid cells and immunosuppressive macrophages. We postulated that these desirable effects of FAK inhibition on the TME might render PDAC tumors more sensitive to immunotherapy. Accordingly, we found that VS-4718 rendered the previously unresponsive KPC mouse model responsive to anti-PD1 and anti-CTLA4 antagonists leading to a nearly tripling of survival times. These data suggest that FAK inhibition increases immune surveillance by overcoming the fibrotic and immunosuppressive PDAC TME thus rendering tumors more responsive to immunotherapy. We treated KP orthotopic tumor-bearing mice with vehicle and FAK inhibitor (FAKi) for 14 days, then extracted total RNA from tumor tissues.
Project description:Aberrant tyrosine kinase activity can influence tumor growth and is regulated by phosphorylation. Pancreatic ductal adenocarcinoma (PDAC) is a very lethal disease, with minimal therapeutic options. We investigated phosphorylated kinases as target in PDAC. Mass spectrometry-based phosphoproteomic analysis was performed of PDAC cell lines to evaluate active kinases. Pathway analysis and inferred kinase activity was performed to identify novel targets. We investigated targeting of focal adhesion kinase in vitro with drug perturbations in combination with chemotherapeutics used against PDAC. Phosphoproteome analysis upon treatment was performed to evaluate signaling..PDAC cell lines portrayed high activity of multiple receptor tyrosine kinases. Non-receptor kinase, focal adhesion kinase (FAK), was identified in all cell lines by our phosphoproteomic screen and pathway analysis. Targeting of this kinase with defactinib validated reduced phosphorylation profiles. Additionally, FAK inhibition had anti-proliferative and anti-migratory effects. Combination with (nab-)paclitaxel had a synergistic effect on cell proliferation in vitro and reduced tumor growth in vivo. In conclusion, our study shows a high phosphorylation of several oncogenic receptor tyrosine kinases in PDAC cells and validated FAK inhibition as potential synergistic target with Nab-paclitaxel
Project description:The goal of this study was to identify transcripts, which are differentially regulatulated in the presence and absence of Focal Adhesion Kinase. As Focal Adhesion Kinase activity can depend upon cell density (Snijder et al. Nature 2009), biological replicates where cells, were seeded very sparsely or confluently, were used. Focal Adhesion Kinase Knockout (ATCC CRL-2644) and Rescue Cells (Sieg et al. 1998, clone DA2) were seeded at two different concentrations. Replicas refer to biological replicates, performed on different days. Only one single technical replicate has been done per biological replicate.
Project description:Targeting of Focal Adhesion Kinase enhances the immunogenic cell death of PEGylated liposome doxorubicin to optimize therapeutic responses of immune checkpoint blockade
Project description:Pancreatic cancer is an aggressive disease with a low 5-year survival rate and poor response to therapy. Here, we demonstrate that inhibition of the myeloid-specific SRC family-kinase HCK impairs pancreatic tumor growth and metastasis by enhancing the infiltration of cytotoxic effector cells, stimulating the activation of myeloid cells, and by reducing the desmoplastic microenvironment. Genetic ablation of HCK also maximizes the therapeutic efficacy of chemotherapy and immunotherapy, and improves progression-free survival in mice. Collectively, our results demonstrate that targeting HCK can overcome barriers that limit responses to therapy, and provide a compelling rationale for HCK to be considered as a drug target to improve the responsiveness of pancreatic tumors to chemotherapy and/or immune checkpoint blockade.
Project description:Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase that plays an important role in proliferation, motility, adhesion, invasion, angiogenesis, and survival signaling. Focal adhesion kinase has been shown to be overexpressed in many types of tumors, including breast cancer at early stages of tumorigenesis. To study the biological role of FAK in breast tumorigenesis, we used FAKsiRNA to down-regulate FAK in MCF-7 cell lines.
Project description:Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase that plays an important role in proliferation, motility, adhesion, invasion, angiogenesis, and survival signaling. Focal adhesion kinase has been shown to be overexpressed in many types of tumors, including breast cancer at early stages of tumorigenesis. To study the biological role of FAK in breast tumorigenesis, we used FAKsiRNA to down-regulate FAK in MCF-7 cell lines. Experiment Overall Design: Eight samples were analyzed in MCF-7, MCF-7-Vector, MCF-7 control (luciferase) siRNA and FAKsiRNA#1, FAKsiRNA#2