A long noncoding RNA MAP3K1-2 promotes proliferation and invasion in gastric cancer

Lei Wu,1 Jia-Huan Yin,1 Yu-Yu Guan,1 Hai-Long Liu,1 Hai-Long Shen,1 Xiao-Jie Wang,1 Bao-Hua Han,1 Min-Wei Zhou,2 Xiao-Dong Gu2 1Department of General Surgery, Shanghai Baoshan Luo Dian Hospital, Shanghai 201908, China; 2Department of General Surgery, Huashan Hospital, Fudan University, Shanghai 200040, China Background: Long noncoding RNAs (lncRNAs) have been implicated in several human cancers. The expression profile and underlying mechanism of the lncRNA MAP3K1-2 in gastric cancer (GC) are poorly understood. Methods: Sixty-one patients with GC were recruited from Shanghai Baoshan Luo Dian Hospital (Shanghai, China). Tumor tissues and paired normal tissues (5 cm adjacent to the tumor) were obtained. Expression of lncRNA MAP3K1-2 in GC cell lines was examined using quantitative real-time polymerase chain reaction. Protein expression was detected using Western blot. Cell cycle analysis was assessed using flow cytometry. Cell proliferation was assessed using soft agar assays, and cell invasion was assessed using Transwell assays. Results: The expression level of lncRNA MAP3K1-2 was upregulated in GC cells and markedly higher in poorly differentiated cell lines. Silencing treatment of lncRNA MAP3K1-2 significantly inhibited cell proliferation and invasion in GC. In addition, knockdown of lncRNA MAP3K1-2 significantly inhibited the function of important genes in the MAPK signaling pathway. Higher expression of lncRNA MAP3K1-2 was often associated with poorer prognosis in patients with GC. Conclusions: lncRNA MAP3K1-2 is a critical effector in GC tumorigenesis and progression, representing novel therapeutic targets. High lncRNA MAP3K1-2 expression may serve as a novel independent prognostic marker for predicting the outcome of GC. Keywords: gastric cancer, long noncoding RNA, MAP3K1-