Abstract 1066: L1CAM as a pivotal mediator for disease progression and prognostic biomarker in gastric cancer patients

Background/Aims: Although significant progress has been made in the diagnosis and treatment of Gastric cancer (GC) patients, GC is the second leading cause of cancer-related deaths worldwide. Identification of critical factors driving the progression of metastasis and new prognostic biomarkers are urgently required to improve both early detection of recurrence and prognosis of patients with advanced GC. L1 cell adhesion molecule (L1CAM) has been observed to be highly expressed in several types of tumors, which may play a vital role in tumor progression. The present study investigated the clinical significance of L1CAM, in the development and progression of gastric cancer. Experimental Design: At first, the effects of L1CAM alteration were investigated using proliferation, migration, invasion, and anoikis and xenograft model. Next, we analyzed L1CAM expression in surgical tissue speciemens from 131 gastric cancer patients (Cohort 1) by quantitative real-time reverse transcription-PCR and 309 patients (Cohort 2) by immunohistochemistry. Results: Knockdown of L1CAM using small interfering RNA in GC cell lines resulted in reduced cell proliferation, invasion, migration, and anoikis in gastric cancer cells. Furthermore, Knockdown of L1CAM inhibited metastasis in a xenograft model. Interestingly, L1CAM expression in cancer tissues was significantly higher in patients with lymph node metastasis and distant metastasis. The expression of L1CAM was significantly associated with poor prognosis. Furthermore, L1CAM emerged as an independent prognostic predictor and a predictor of lymph node metastasis in GC patients. Conclusions: Our data highlight that L1CAM appear to play an important role in disease development and L1CAM expression may serve as a novel predictor for the identification of patients who are at high risk for tumor recurrence and strict surveillance in curative GC patients. Citation Format: Yoshinaga Okugawa, Yuji Toiyama, Yasuhiko Mohri, Akira Yamamoto, Tsunehiko Shigemori, Chengzeng Yin, Aya Narumi, Shozo Ide, Takahito Kitajima, Hiromi Yasuda, Hiroyuki Fujikawa, Junichiro Hiro, Shigeyuki Yoshiyama, Masaki Ohi, Koji Tanaka, Toshimitsu Araki, Masato Kusunoki. L1CAM as a pivotal mediator for disease progression and prognostic biomarker in gastric cancer patients [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 1066