Abstract 1172: Expression of notch1, numb, and musashi1 in non-small cell lung cancer

Abstract

Abstract Background: Deregulation of Notch pathway is associated with carcinogenesis, and Notch signaling is identified as tumor activator in non-small cell lung cancer(NSCLC). The function of Musashi1 has been found to activate Notch signaling through the translational repression of Numb, which represses an intracellular Notch signaling. In NSCLC, the association between Numb or Musashi1 expression and clinicopathological factors or prognosis has remained unclear. In this study, we evaluated the expression of Notch1, Numb, and Musashi1 in NSCLC. Methods: A total of 135 surgically resected NSCLCs were immunohistochemically assessed for Notch1, Numb, and Musashi1 expression. Only cytoplasm and nuclear staining was considered in the evaluation of activated Notch1 expression. The immunoscores were determined, and then its correlation with either the clinicopathological variables or the survival outcomes was analyzed. Results: Immunohistochemical reactivity for Numb, and Musashi1 was detected in the cytoplasm and nuclear of the tumor cells. Notch1 expression was associated with several clinicopathological factors, including pathological histology (p = 0.002), and differentiation of tumor (p = 0.024). Numb expression was also associated with several clinicopathological factors, including sex (p = 0.037), smoking habit (p = 0.033), pathological histology (p = 0.002), and differentiation of tumor (p = 0.015). No correlations were noted between Musashi1 expression and any of the variables. Analysis of cellular biological expression demonstrated a link between low Numb expression and high Notch expression. Multivariate Cox regression analysis showed that positive Numb expression was an independent favorable prognostic factor. Conclusions: We demonstrate that Numb expression was associated with better prognosis in NSCLC. Numb might have the function as tumor suppressor in NSCLC. Citation Format: Hajime Kikuchi, Jun Sakakibara-Konishi, Yasuyuki Ikezawa, Taichi Takashina, Hidenori Mizugaki, Eiki Kikuchi, Junko Kikuchi, Naofumi Shinagawa, Satoshi Oizumi, Yasuhiro Hida, Kichizo Kaga, Ichiro Kinoshita, Hirotoshi Dosaka-Akita, Masaharu Nishimura. Expression of notch1, numb, and musashi1 in non-small cell lung cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1172.