Abstract 5184: Expression and role of regulator of G-protein signing 5 in squamous cell carcinoma of the tongue

Objective: Regulator of G-protein signing (RGS) 5 is a member of the RGS family and acts as GTPase-activating proteins for heterotorimeric G protein αsubunits, negatively regulating G-protein signaling. RGS5 was reportedly expressed in the heart, lung, skeletal muscle and small intestine and relates with tumor angiogenesis and gestational hypertension. It was reported that RGS5 was related with the invasion and metastasis of cancers, such as non-small lung cancer and hepatocellular carcinoma. In the present study, we examined RGS5 expression and its relation with invasion in squamous cell carcinoma (SCC) of the tongue. Materials and Methods: For immunohistochemical analysis for RGS5, we used SCC tissues of the tongue obtained from 43 patients who underwent resection at Kurume University Hospital from 2011 to 2015. The staining intensity was graded as 0, negative; 1, weak; 2, moderate; 3, strong. The staining intensity in the normal epithelium was used as an internal control. We examined relationship between RGS5 expression in invasive portions and clinicopathological features (e.g., lymph node metastasis, depth of tumor, and mode of invasion, and so forth). Mode of invasion was classified into 3 levels, i.e., IFNa (expansive), IFNc (invasive), IFNb (between INFa and INFc). Depth of tumor was measured and classified into 2 levels: Citation Format: Yushi Abe, Hirohisa Yano, Jun Akiba, Reiichirou kondou, Sachiko Ogasawara, Ken Nakamura, Zingo Kusukawa. Expression and role of regulator of G-protein signing 5 in squamous cell carcinoma of the tongue [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5184.