Abstract 422: Functional analysis of family with sequence similarity 83, member B in lung adenocarcinoma

Background: We have reported the usefulness of Family with sequence similarity 83, member B (FAM83B) as a novel biomarker for diagnosis and prognosis of lung squamous cell carcinoma. FAM83B expresses not only in lung cancer but also in several types of solid cancer such as breast, esophageal, and so on. More recently, novel finding showing FAM83B involve to the resistance of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) in breast cancer cell lines has been shown. EGFR signaling pathway also plays an important role in lung adenocarcinoma, therefore we hypothesize that FAM83B associates to the tumor proliferation in lung adenocarcinoma, and its results in the resistance to EGFR TKI and in a novel therapeutic target in lung adenocarcinoma. Materials and methods: Sixty-four paired tumor and corresponding normal tissue samples obtained from patients with lung adenocarcinoma who underwent surgical resection since 2008 to 2011 were subjected. FAM83B mRNA expression were examined and analyzed relationship between the level of FAM83B and clinicopathological variables. Then, FAM83B knock down study was performed in several types of cancer cell lines (PC-14, H820, H1650, H1975, HLC-1, H2347) to understand whether FAM83B involve to cell proliferation. Results: Multivariate analysis show that smaller cancer(≦3cm vs >3cm, p = 0.044), and wild type EGFR(wild type vs. mutant, p = 0.004) tend to express higher FAM83B mRNA. There is no significant difference between FAM83B expression and progression-free survival. FAM83B knock down results in suppression of proliferation in HLC-1, H1650, which express high level of FAM83B protein. Conclusions: FAM83B could involve to tumor proliferation of lung adenocarcinoma in part, and could be the novel therapeutic target. Citation Format: Takumi Yamaura, Naoyuki Okabe, Hironori Takagi, Yuki Owada, Takuya Inoue, Yuzuru Watanabe, Mitsuro Fukuhara, Satoshi Muto, Yuki Matsumura, Takeo Hasegawa, Atsushi Yonechi, Mika Hoshino, Jun Osugi, Yutaka Shio, Mitsunori Higuchi, Junji Ezaki, Satoshi Waguri, Mitsukazu Gotoh, Hiroyuki Suzuki. Functional analysis of family with sequence similarity 83, member B in lung adenocarcinoma. [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 422.