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>
Project description:Brain metastatic disease occurs in 10-30% of metastatic breast cancer cases. The incidence of brain metastases is increasing with median overall survival < 2 years for patients. In order to better characterize oncogenic pathway activity pertinent to breast cancer brain metastasis, exome capture RNA sequencing was carried out on patient matched primary breast with brain metastatic tumor samples for 45 cases of breast cancer brain metastasis (N= 90 samples). Here, exome capture RNA sequencing data is deposited as sequencing batch corrected log2 transformed trimmed M of means (TMM) normalized counts per million (CPM) (log2(TMM-CPM +1) gene expression values (n=16,714 protein coding genes; N=90 tumor samples).
Project description:Brain metastatic disease occurs in 10-30% of metastatic breast cancer cases. The incidence of brain metastases is increasing with median overall survival < 2 years for patients. In order to better characterize oncogenic pathway activity pertinent to breast cancer brain metastasis, exome capture RNA sequencing was carried out on patient matched primary breast with brain metastatic tumor samples for 45 cases of breast cancer brain metastasis (N= 90 samples). Here, exome capture RNA sequencing data is deposited as sequencing batch corrected log2 transformed trimmed M of means (TMM) normalized counts per million (CPM) (log2(TMM-CPM +1) gene expression values (n=16,714 protein coding genes; N=90 tumor samples).
Project description:RNA-sequencing (RNA-Seq) protocols and bioinformatic pipelines are designed to streamline downstream analyses on sequences believed to be the most important. Here, we have challenged this dogma by preserving ribosomal RNA (rRNA) in our samples and by lowering the minimal RNA size window of our small RNA-Seq analyses to 8 nt