Losartan treatment enhances chemotherapy efficacy and reduces ascites in ovarian cancer models by normalizing the tumor stroma
Menée à l'aide de deux modèles de xénogreffes de carcinome ovarien humain, cette étude met en évidence un mécanisme par lequel le losartan, un inhibiteur de l'angiotensine II, améliore l'efficacité du paclitaxel et réduit le développement d'ascites en normalisant le stroma tumoral
Despite initial responsiveness to chemotherapy, the overwhelming majority of advanced ovarian cancer patients relapse with resistant disease. Thus, developing more effective strategies for ovarian cancer treatment is a high clinical priority. Here, we report that targeting angiotensin signaling with losartan, an angiotensin receptor blocker, can reduce extracellular matrix in ovarian tumors and the associated physical barriers that normally hinder drug delivery and efficacy. These changes in the tumor microenvironment lead to improved response to chemotherapy, and, importantly, decrease ascites—a major burden for ovarian cancer patients. These preclinical findings are in concert with our retrospective analysis showing improved survival in patients receiving angiotensin system inhibitors concurrently with standard treatment for ovarian cancer and should be tested in a clinical trial.In ovarian cancer patients, tumor fibrosis and angiotensin-driven fibrogenic signaling have been shown to inversely correlate with survival. We sought to enhance drug delivery and therapeutic efficacy by remodeling the dense extracellular matrix in two orthotopic human ovarian carcinoma xenograft models. We hypothesized that targeting the angiotensin signaling axis with losartan, an approved angiotensin system inhibitor, could reduce extracellular matrix content and the associated “solid stress,” leading to better anticancer therapeutic effect. We report here four translatable findings: (i) losartan treatment enhances the efficacy of paclitaxel—a drug used for ovarian cancer treatment—via normalizing the tumor microenvironment, resulting in improved vessel perfusion and drug delivery; (ii) losartan depletes matrix via inducing antifibrotic miRNAs that should be tested as candidate biomarkers of response or resistance to chemotherapy; (iii) although losartan therapy alone does not reduce tumor burden, it reduces both the incidence and the amount of ascites formed; and (iv) our retrospective analysis revealed that patients receiving angiotensin system inhibitors concurrently with standard treatment for ovarian cancer exhibited 30 mo longer overall survival compared with patients on other antihypertensives. Our findings provide the rationale and supporting data for a clinical trial on combined losartan and chemotherapy in ovarian cancer patients.