Chronic inflammation promotes tumor development, as infectious and chemical agents, as well as chronic inflammatory disorders, have been shown to increase the risk of developing tumors. Solid tumors are heavily invested with tumor-associated macrophages, which promote angiogenesis, immunosuppression and tumor growth, progression, and metastasis. Targeting the mechanisms controlling myeloid cell recruitment to tumors is a promising approach to suppressing tumor growth and metastasis. We recently found that myeloid cell recruitment to tumors depends on PI3kinase ? (p110?). Pharmacological or genetic blockade of p110? suppressed myeloid cell adhesion to endothelium and recruitment to tumors, as well as angiogenesis, growth and metastasis of implanted and spontaneous tumors, revealing that p110? is an important therapeutic target in oncology. Importantly, p110? is the major PI3-kinase isoform expressed in myeloid cells;furthermore, myeloid cells are the main physiological source of p110?. Selective inhibitors of p110? could thus serve as therapeutics to suppress tumor malignancy by blocking diverse pathways promoting tumor inflammation.
The aims of this proposal are 1) to determine the molecular pathways by which PI3kinase gamma regulates myeloid cell trafficking during inflammation, tumor progression and metastasis, 2) to evaluate the role of PI3K? in the regulation of immunosuppression during tumor progression, and 3) to evaluate the potential of PI3- kinase ? to serve as a therapeutic target for the treatment of breast cancer.
Recent studies have shown that inflammation plays a critical role in promoting tumor growth, progression and metastasis. Tumor associated macrophages promote angiogenesis, suppress immunity and stimulate tumor cell invasion and survival, which combine to promote tumor growth, spread and organ dysfunction. The overall goal of the proposed research is to explore the mechanistic roles of PI3kinase gamma in the regulation of tumor inflammation, growth and metastasis and to evaluate the potential of this myeloid cell kinase to serve as a target for novel tumor therapeutic strategies.
|Kaneda, Megan M; Messer, Karen S; Ralainirina, Natacha et al. (2016) PI3K? is a molecular switch that controls immune suppression. Nature 539:437-442|
|Kaneda, Megan M; Cappello, Paola; Nguyen, Abraham V et al. (2016) Macrophage PI3K? Drives Pancreatic Ductal Adenocarcinoma Progression. Cancer Discov 6:870-85|
|Gunderson, Andrew J; Kaneda, Megan M; Tsujikawa, Takahiro et al. (2016) Bruton Tyrosine Kinase-Dependent Immune Cell Cross-talk Drives Pancreas Cancer. Cancer Discov 6:270-85|
|Young, Shanique A; McCabe, Katelyn E; Bartakova, Alena et al. (2015) Integrin ?4 Enhances Metastasis and May Be Associated with Poor Prognosis in MYCN-low Neuroblastoma. PLoS One 10:e0120815|
|Garmy-Susini, Barbara; Avraamides, Christie J; Desgrosellier, Jay S et al. (2013) PI3K? activates integrin ?4?1 to establish a metastatic niche in lymph nodes. Proc Natl Acad Sci U S A 110:9042-7|
|Schmid, Michael C; Franco, Irene; Kang, Sang Won et al. (2013) PI3-kinase ? promotes Rap1a-mediated activation of myeloid cell integrin ?4?1, leading to tumor inflammation and growth. PLoS One 8:e60226|
|Schmid, Michael C; Varner, Judith A (2012) Myeloid cells in tumor inflammation. Vasc Cell 4:14|
|Kato, Hisashi; Liao, Zhongji; Mitsios, John V et al. (2012) The primacy of ?1 integrin activation in the metastatic cascade. PLoS One 7:e46576|
|Schmid, Michael C; Avraamides, Christie J; Foubert, Philippe et al. (2011) Combined blockade of integrin-?4?1 plus cytokines SDF-1? or IL-1? potently inhibits tumor inflammation and growth. Cancer Res 71:6965-75|
|Schmid, Michael C; Avraamides, Christie J; Dippold, Holly C et al. (2011) Receptor tyrosine kinases and TLR/IL1Rs unexpectedly activate myeloid cell PI3k?, a single convergent point promoting tumor inflammation and progression. Cancer Cell 19:715-27|