Project description:A key feature of ovarian high-grade serous carcinoma is frequent amplification of the 3q26 locus. Here we show that PRKCI, located on the 3q26 locus is not only amplified and overexpressed in 78% of HGSC patient samples but is also expressed in early fallopian tube lesions, called Serous Tubal Intraepithelial Carcinoma. In vivo studies in a transgenic mouse model establish PRKCI as an ovarian cancer oncogene and identify YAP1 as a downstream regulator. Together, PRKCI and YAP1 regulate TNFα to promote an immune suppressive microenvironment and inhibit cytotoxic T-cell infiltration in tumors. High PRKCI expressing human ovarian tumors show decreased cytotoxic T-cell infiltration. Taken together, we identify PRKCI and YAP1 as key mediators of a tumor-promoting immune microenvironment in ovarian cancer.
Project description:A key feature of serous ovarian cancer is frequent amplification in the 3q26 locus, which harbors the PRKCI gene. Here we show that PRKCI is amplified and overexpressed in a 78% of high-grade serous ovarian carcinoma. Our in vivo studies with orthotopic mouse models establish it as an ovarian cancer oncogene. This oncogenic property of PRKCI is mediated by regulation of YAP1 activity. Accordingly YAP1 knockdown partially rescues PRKCI mediated tumorigenesis. Integrated gene expression profiling and YAP1 promoter occupancy analyses reveal that PRKCI and YAP1 cooperate to transcriptionally regulate genes affecting the tumor immune microenvironment. Consistently, CD11b+Gr1+Ly6G+ MDSCs are increased in the tumor microenvironment of PRKCI over-expressing tumors. Importantly, we show that elevated PRKCI expression in high-grade serous ovarian carcinomas strongly correlated with assignment to immunoreactive subtype. In summary, we identify PRKCI and YAP1 as key mediators of a tumor-promoting immunosuppressive microenvironment in ovarian cancers.
Project description:A key feature of serous ovarian cancer is frequent amplification in the 3q26 locus, which harbors the PRKCI gene. Here we show that PRKCI is amplified and overexpressed in a 78% of high-grade serous ovarian carcinoma. Our in vivo studies with orthotopic mouse models establish it as an ovarian cancer oncogene. This oncogenic property of PRKCI is mediated by regulation of YAP1 activity. Accordingly YAP1 knockdown partially rescues PRKCI mediated tumorigenesis. Integrated gene expression profiling and YAP1 promoter occupancy analyses reveal that PRKCI and YAP1 cooperate to transcriptionally regulate genes affecting the tumor immune microenvironment. Consistently, CD11b+Gr1+Ly6G+ MDSCs are increased in the tumor microenvironment of PRKCI over-expressing tumors. Importantly, we show that elevated PRKCI expression in high-grade serous ovarian carcinomas strongly correlated with assignment to immunoreactive subtype. In summary, we identify PRKCI and YAP1 as key mediators of a tumor-promoting immunosuppressive microenvironment in ovarian cancers.
Project description:A key feature of high-grade serous ovarian carcinoma (HGSOC) is frequent amplification of the 3q26 locus harboring PRKC-iota (PRKCI). Here, we show that PRKCI is also expressed in early fallopian tube lesions, called Serous Tubal Intraepithelial Carcinoma. Transgenic mouse studies establish PRKCI as an ovarian cancer specific oncogene and system level and functional analyses identify YAP1 as a downstream effector in tumor progression. Mechanistically, the oncogenic activity of the PRKCI-YAP1 axis relates in part to the upregulation of TNFα to promote an immune suppressive tumor microenvironment characterized by an abundance of myeloid-derived suppressor cells and inhibition of cytotoxic T cell infiltration. In human ovarian cancers, high PRKCI expression also correlates with high expression of YAP1 and low infiltration of cytotoxic T-cell. The PRKCI-YAP1 regulation of the tumor immunity provides a therapeutic strategy for highly lethal ovarian cancer. Robust multi-array average (RMA) method was used with default options (with background correction, quantile normalization, and log transformation) to normalize raw data from batches using R/Bioconductor‘s affy package
Project description:<p>BRCA1 mutations are a hallmark of hereditary ovarian cancer, strongly linked to deficiencies in homologous recombination (HR) DNA repair and impaired DNA replication fork protection. However, its roles in cancer progression beyond maintaining genomic integrity remain poorly understood. Through metabolomics approaches, we found BRCA1-deficiency strikingly increased choline metabolism. Loss of BRCA1 promotes choline uptake through upregulating choline transporter-like protein 4 (CTL4). BRCA1 directly binds and recruits EZH2-mediated H3K27Me3 deposition to CTL4 promoter. CTL4 was therefore overexpressed in ovarian cancer tissues with BRCA1 mutations. Furthermore, BRCA1-deficiency significantly promotes ovarian cancer invasion, while inhibition of CTL4 reverses the high metastatic potential of BRCA1-deficient ovarian cancer cells, suggesting the functionality and specificity of CTL4 as a therapeutic target. Additionally, we discovered that phosphocholine, the choline metabolite increased by CTL4 overexpression, interacted with and stabilized the epithelial-to-mesenchymal transition inducer FAM3C in BRCA1-deficient ovarian cancer cells. Importantly, we identified a potent CTL4 inhibitor, DT-13, which significantly reduces choline metabolism and effectively suppresses metastasis in BRCA1-deficient ovarian cancers. Therefore, our study uncovers a mechanism underlying metastasis in BRCA1-deficient cancers and identifies CTL4 as a therapeutic target for metastatic ovarian cancer patients with BRCA1 mutations.</p>