High expression of LY6E is an independent prognostic factor of colorectal cancer patients

Colorectal cancer (CRC) is common cancer worldwide, and the 5-year relative survival rate of CRC patients with distant metastasis is as low as 14%. Therefore, identifying markers of CRC is important for the early detection of CRC and applying appropriate treatment strategies. The lymphocyte antigen 6 family (LY6 family) is closely related to the behavior of various cancer types. Among the LY6 family, the lymphocyte antigen 6 complex, locus E (LY6E), which is specifically highly expressed in CRC. Hence, the effects of LY6E on cell function in CRC and its role in CRC recurrence and metastasis were investigated. Reverse transcription-quantitative PCR, western blotting and in vitro functional studies were carried out using four CRC cell lines. Immunohistochemical analysis of 110 CRC tissues was performed to explore the biological functions and expression patterns of LY6E in CRC. LY6E was overexpressed CRC tissues compared with that in adjacent normal tissues. High expression of LY6E in CRC tissues was an independent prognostic factor of worse overall survival (P=0.048). Knockdown of LY6E using small interfering RNA inhibited CRC cell proliferation, migration, invasion, and soft agar colony formation, indicating some of its effects on CRC carcinogenic functions. High expression of LY6E may have oncogenic functions in CRC and be useful as a valuable prognostic marker and potential therapeutic target for CRC.