Project description:Peritoneal carcinomatosis is a frequent finding in patients with primary gastric cancer, and it is associated with a poor prognosis. A major mechanism in peritoneal carcinomatosis is the dissemination of cancer cells into the abdominal cavity, mainly in diffuse gastric adenocarcinoma. The features that enable diffuse primary gastric tumours to develop peritoneal dissemination have been little investigated and are only incompletely understood. We therefore compared the gene expression profile in patients with diffuse primary gastric cancer with and without peritoneal carcinomatosis. Specimens from consecutive gastric cancer patients with and without peritoneal carcinomatosis were investigated using oligonucleotide microarrays. Keywords: Disease state analysis
Project description:Characterizations of ascites proteome from ovarian peritoneal carcinomatosis (PC) and gastric PC have demonstrated that ascites contains elevated pro-tumorigenic factors. Reasoning that the composition of ascitic fluid might offer insight into the memory of key biological events occurring intra-abdominally, we hypothesized that paracrine factors essential for survival and growth of peritoneal deposits are secreted into and circulate within ascitic fluid. Our data from cytokine array profile suggest that ascites contains biologically active ligands capable of supporting cellular functions of cancer cells. To decipher downstream signalling pathways activated in cancer cells when exposed to ascites, we performed gene expression analysis of Colo-205 cells upon exposure to PC ascites and ligand inhibitor.
Project description:Peritoneal carcinomatosis is a common yet deadly manifestation of gastrointestinal cancers, with few effective treatments. To identify targetable determinants of peritoneal metastasis, we focused on appendiceal adenocarcinoma (AC), a gastrointestinal cancer that metastasizes almost exclusively to the peritoneum. Current treatments are extrapolated from colorectal cancer (CRC), yet AC has distinct genomic alterations, mucinous morphology and peritoneum restricted metastatic pattern. Further, no stable preclinical models of AC exist, limiting drug discovery and representing an unmet clinical need. We establish a first-in-class stable biobank of 16 long-term cultured AC patient-derived organoids (PDOs), including 3 matched primary AC-peritoneal carcinomatosis (AC-PC) pairs. By enriching for cancer cells, AC PDOs enable accurate genomic characterization relative to paucicellular AC tissue. We establish an organoid orthotopic intraperitoneal xenograft model that recapitulates diffuse peritoneal carcinomatosis and show that PC-organoids retain increased metastatic capacity, decreased growth factor dependency and sensitivity to standard of care chemotherapy relative to matched primary AC organoids. Single cell profiling of AC-PC pairs reveals dedifferentiation from mucinous differentiated states in primary AC into intestinal stem cell and fetal progenitor states in PC, with upregulation of oncogenic signaling pathways. Through hypothesis-driven drug testing, we identify RAS inhibitor RMC-7977 and Wnt-targeting tyrosine kinase inhibitor WNTinib as novel, clinically actionable strategies to more effectively target AC-PC.
Project description:To identify the proteome of human peritoneal tissue, 43 FFPE and 5 fresh frozen peritoneal tissue samples at healthy or non-cancerous state were collected and subjected to mass spectrometry analysis. The resulting findings represnt a baseline catalog of the proteomic composition of the peritoneum, as a comparison dataset for future studies focused on alterations in pathologic states such as peritoneal carcinomatosis.