ADH1B promotes mesothelial clearance and ovarian cancer infiltration.
ABSTRACT: Primary debulking surgery followed by adjuvant chemotherapy is the standard treatment for ovarian cancer. Residual disease after primary surgery is associated with poor patient outcome. Previously, we discovered ADH1B to be a molecular biomarker of residual disease. In the current study, we investigated the functional role of ADH1B in promoting ovarian cancer cell invasiveness and contributing to residual disease. We discovered that ADH1B overexpression leads to a more infiltrative cancer cell phenotype, promotes metastasis, increases the adhesion of cancer cells to mesothelial cells, and increases extracellular matrix degradation. Live cell imaging revealed that ADH1B-overexpressing cancer cells efficiently cleared the mesothelial cell layer compared to control cells. Moreover, gene array analysis revealed that ADH1B affects several pathways related to the migration and invasion of cancer cells. We also discovered that hypoxia increases ADH1B expression in ovarian cancer cells. Collectively, these findings indicate that ADH1B plays an important role in the pathways that promote ovarian cancer cell infiltration and may increase the likelihood of residual disease following surgery.
Project description:RNA-sequencing analysis was carried out on ascetic fluid-isolated mesothelial cells from ovarian cancer patients compared to control human peritoneal mesothelial cells to identify a mesothelial-mesenchymal gene signature. Overall design: Three control human peritoneal mesothelial cell samples isolated from omentum obtained from non-oncologic patients undergoing abdominal surgery and three ascitic fluid-isolated mesothelial cell samples obtained from the peritoneal effucsions of stage III/IV ovarian serous carcinoma patients
Project description:Residual disease following primary cytoreduction is associated with adverse overall survival in patients with epithelial ovarian cancer. Accurate identification of patients at high risk of residual disease has been elusive, lacking external validity and prompting many to undergo unnecessary surgical exploration. Our goal was to identify and validate molecular markers associated with high rates of residual disease.We interrogated two publicly available datasets from chemonaïve primary high-grade serous ovarian tumors for genes overexpressed in patients with residual disease and significant at a 10% false discovery rate (FDR) in both datasets. We selected genes with wide dynamic range for validation in an independent cohort using quantitative RT-PCR to assay gene expression, followed by blinded prediction of a patient subset at high risk for residual disease. Predictive success was evaluated using a one-sided Fisher exact test.Forty-seven probe sets met the 10% FDR criterion in both datasets. These included FABP4 and ADH1B, which tracked tightly, showed dynamic ranges >16-fold and had high expression levels associated with increased incidence of residual disease. In the validation cohort (n = 139), FABP4 and ADH1B were again highly correlated. Using the top quartile of FABP4 PCR values as a prespecified threshold, we found 30 of 35 cases of residual disease in the predicted high-risk group (positive predictive value = 86%) and 54 of 104 among the remaining patients (P = 0.0002; OR, 5.5).High FABP4 and ADH1B expression is associated with significantly higher risk of residual disease in high-grade serous ovarian cancer. Patients with high tumoral levels of these genes may be candidates for neoadjuvant chemotherapy.
Project description:Dissemination of ovarian tumors involves the implantation of cancer spheroids into the mesothelial monolayer on the walls of peritoneal and pleural cavity organs. Biopsies of tumors attached to peritoneal organs show that mesothelial cells are not present under tumor masses. We have developed a live, image-based in vitro model in which interactions between tumor spheroids and mesothelial cells can be monitored in real time to provide spatial and temporal understanding of mesothelial clearance. Here we provide evidence that ovarian cancer spheroids utilize integrin- and talin- dependent activation of myosin and traction force to promote mesothelial cells displacement from underneath a tumor cell spheroid. These results suggest that ovarian tumor cell clusters gain access to the sub-mesothelial environment by exerting force on the mesothelial cells lining target organs, driving migration and clearance of the mesothelial cells.
Project description:RNA-sequencing analysis was carried out on ascitic fluid-isolated mesothelial cells from ovarian cancer patients compared to control human peritoneal mesothelial cells. Overall design: Three control human peritoneal mesothelial cell samples isolated from omentum obtained from non-oncologic patients undergoing abdominal surgery and four ascitic fluid-isolated mesothelial cell samples obtained from the peritoneal effucsions of stage III/IV
Project description:Metastatic dissemination of ovarian tumors involves the invasion of tumor cell clusters into the mesothelial cell lining of peritoneal cavity organs; however, the tumor-specific factors that allow ovarian cancer cells to spread are unclear. We used an in vitro assay that models the initial step of ovarian cancer metastasis, clearance of the mesothelial cell layer, to examine the clearance ability of a large panel of both established and primary ovarian tumor cells. Comparison of the gene and protein expression profiles of clearance-competent and clearance-incompetent cells revealed that mesenchymal genes are enriched in tumor populations that display strong clearance activity, while epithelial genes are enriched in those with weak or undetectable activity. Overexpression of transcription factors SNAI1, TWIST1, and ZEB1, which regulate the epithelial-to-mesenchymal transition (EMT), promoted mesothelial clearance in cell lines with weak activity, while knockdown of the EMT-regulatory transcription factors TWIST1 and ZEB1 attenuated mesothelial clearance in ovarian cancer cell lines with strong activity. These findings provide important insights into the mechanisms associated with metastatic progression of ovarian cancer and suggest that inhibiting pathways that drive mesenchymal programs may suppress tumor cell invasion of peritoneal tissues.
Project description:Missense mutations in the TP53 gene resulting in the accumulation of mutant proteins are extremely common in advanced ovarian cancer, which is characterised by peritoneal metastasis. Attachment of cancer cells to the peritoneal mesothelium is regarded as an initial, key step for the metastatic spread of ovarian cancer. In the present study, we investigated the possible role of a p53 mutant in the mesothelial adhesion of ovarian cancer cells. We found that OVCAR-3 cells with the R248 TP53 mutation (p53(R248)) were more adhesive to mesothelial Met5A cells than were A2780 cells expressing wild-type p53. In addition, ectopic expression of p53(R248) in p53-null SKOV-3 cells significantly increased adhesion to Met5A cells. Knockdown of mutant p53 significantly compromised p53(R248)-induced cell adhesion to Met5A cells. Microarray analysis revealed that several adhesion-related genes, including integrin β4, were markedly up-regulated, and certain signalling pathways, including PI3K/Akt, were activated in p53(R248) transfectants of SKOV-3 cells. Inhibition of integrin β4 and Akt signalling using blocking antibody and the inhibitor LY294002, respectively, significantly attenuated p53(R248)-mediated ovarian cancer-mesothelial adhesion. These data suggest that the p53(R248) mutant endows ovarian cancer cells with increased adhesiveness and that integrin β4 and Akt signalling are associated with the mutation-enhanced ovarian cancer-mesothelial cell adhesion.
Project description:The interplay between peritoneal mesothelial cells and ovarian cancer cells is critical for the initiation and peritoneal dissemination of, and ascites formation in, ovarian cancer. The production of lysophosphatidic acid (LPA) by both peritoneal mesothelial cells and ovarian cancer cells has been shown to promote metastatic phenotype in ovarian cancer. Herein, we report that exogenous addition or ectopic overexpression of the matricellular protein SPARC (secreted protein acidic and rich in cysteine) significantly attenuated LPA-induced proliferation, chemotaxis, and invasion in both highly metastatic SKOV3 and less metastatic OVCAR3 ovarian cancer cell lines. SPARC appears to modulate these functions, at least in part, through the regulation of LPA receptor levels and the attenuation of extracellular signal-regulated kinase (ERK) 1/2 and protein kinase B/AKT signaling. Moreover, our results show that SPARC not only significantly inhibited both basal and LPA-induced interleukin (IL) 6 production in both cell lines but also attenuated IL-6-induced mitogenic, chemotactic, and proinvasive effects, in part, through significant suppression of ERK1/2 and, to a lesser extent, of signal transducers and activators of transcription 3 signaling pathways. Our results strongly suggest that SPARC exerts a dual inhibitory effect on LPA-induced mesothelial-ovarian cancer cell crosstalk through the regulation of both LPA-induced IL-6 production and function. Taken together, our findings underscore the use of SPARC as a potential therapeutic candidate in peritoneal ovarian carcinomatosis.
Project description:Peritoneal metastases are the leading cause of morbidity and mortality in high-grade serous ovarian cancer (HGSOC). Accumulating evidence suggests that mesothelial cells are an important component of the metastatic microenvironment in HGSOC. However, the mechanisms by which mesothelial cells promote metastasis are unclear. Here, we report that the HGSOC tumor-mesothelial niche was hypoxic, and hypoxic signaling enhanced collagen I deposition by mesothelial cells. Specifically, hypoxic signaling increased expression of lysyl oxidase (LOX) in mesothelial and ovarian cancer cells to promote collagen crosslinking and tumor cell invasion. The mesothelial niche was enriched with fibrillar collagen in human and murine omental metastases. Pharmacologic inhibition of LOX reduced tumor burden and collagen remodeling in murine omental metastases. These findings highlight an important role for hypoxia and mesothelial cells in the modification of the extracellular matrix and tumor invasion in HGSOC. SIGNIFICANCE: This study identifies HIF/LOX signaling as a potential therapeutic target to inhibit collagen remodeling and tumor progression in HGSOC.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/79/9/2271/F1.large.jpg.
Project description:Notch3 gene amplification and pathway activation have been reported in ovarian serous carcinoma. However, the primary Notch3 ligand that initiates signal transduction in ovarian cancer remains unclear. In this report, we identify Jagged-1 as the highest expressed Notch ligand in ovarian tumor cells as well as in peritoneal mesothelial cells that are in direct contact with disseminated ovarian cancer cells. Cell-cell adhesion and cellular proliferation were reduced in Notch3-expressing ovarian cancer cells that were cocultured with Jagged-1 knockdown mesothelial and tumor feeder cells. Interaction of Notch3-expressing ovarian cancer cells with Jagged-1-expressing feeder cells activated the promoter activity of candidate Notch3 target genes, and this activity was attenuated by Notch3 siRNA. Constitutive expression of the Notch3 intracellular domain significantly suppressed the Jagged-1 shRNA-mediated growth inhibitory effect. In Notch3-expressing ovarian cancer cells, Jagged-1-stimulating peptides enhanced cellular proliferation, which was suppressed by gamma-secretase inhibitor and Notch3 siRNA. Taken together, our results show that Jagged-1 is the primary Notch3 ligand in ovarian carcinoma and Jagged-1/Notch3 interaction constitutes a juxtacrine loop promoting proliferation and dissemination of ovarian cancer cells within the intraperitoneal cavity.
Project description:Primary cytoreductive surgery followed by adjuvant chemotherapy is the standard treatment for advanced epithelial ovarian cancer. The average interval between surgery and chemotherapy initiation is approximately 4-weeks at most centers; however, since surgery may accelerate residual tumor growth, a shorter interval may be more beneficial.The murine ID8 cell model of ovarian cancer was used to examine the efficacy of cisplatin treatment administered perioperatively or 7 days after surgical wounding. Luciferase-expressing cells ID8 cells were injected intraperitoneally (i.p.) into female C57/Bl6 mice. Fourteen days post-injection, animals received an abdominal incision or anesthesia alone and received i.p. cisplatin either on the surgical day or 7 days later, or received no chemotherapy. Additional animals received cisplatin 28 days after wounding for comparison.Abdominal tumor mass increased 2.5-fold in wounded vs. unwounded animals as determined by bioluminescent in vivo tumor imaging. Cisplatin administered on the day of wounding decreased tumor burden by 50%, as compared to 90% in unwounded animals. Cisplatin on day 7 or day 28 decreased tumor burden by 80 and 37% respectively.Surgical wounding increases ovarian tumor mass and decreases perioperative cisplatin efficacy in this animal model. Administration of cisplatin 1 week after surgery was more effective than cisplatin administered perioperatively or 4 weeks after surgery.