Abstract 895: The identification of molecular mechanism underlying the progression of gastric cancer peritoneal dissemination by senescent fibroblasts

Abstract

Abstract Background: Secreted factors from cancer associated fibroblast (CAFs) is likely to be implicated in cancer progression, but the precise mechanism is not fully understood. It is reported that senescent cells survive and secrete some cytokines, so called senescence-associated secretory phenotype (SASP). The purpose of current study is to identify the molecular mechanism underlying the progression of gastric cancer (GC) peritoneal dissemination by CAFs showing SASP. Methods: We examined the senescent state of CAFs activated NFkB signaling by inflammatory cytokines (iCAFs) and evaluated the expression of SASP factors. We investigated the growth ability of GC cell lines treated with iCAFs derived condition medium (CM). We transplanted GC cell lines with intraperitoneal administration to generate peritoneal metastasis mouse model and evaluated the influence of SASP factors on cancer progression. Results: We found that the growth ability of iCAFs decreased and their expression of p16 and p15, which was senescent markers increased. And the comprehensive genomic analysis revealed that iCAFs was highly enriched the senescent related genes and SASP factors related genes. Next, we also found that iCAFs derived CM significantly increased the growth ability of GC cells. Moreover, also in peritoneal metastasis mouse model, iCAFs derived CM remarkably enhanced intraperitoneal tumors. Conclusion: These findings suggest that SASP factors from senescent CAFs, which activated by inflammatory cytokines can promote peritoneal dissemination of GC cells. Citation Format: Tadahito Yasuda, Mayu Koiwa, Tomoyuki Uchihara, Atsuko Yonemura. The identification of molecular mechanism underlying the progression of gastric cancer peritoneal dissemination by senescent fibroblasts [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 895.