Stathmin 1 promotes the progression of liver cancer through interacting with YAP1.

OBJECTIVE The present study aimed to explore whether Hippo/YAP signaling pathway was involved in STMN1 (stathmin 1)-mediated liver cancer progression. PATIENTS AND METHODS STMN1 expression patterns were determined by Real Time-Polymerase Chain Reaction (PCR) assay (RT-PCR) and Western blotting. The relationship between STMN1 expression levels and the clinical features and the prognosis of patients with liver cancer were evaluated by χ2-test and student's t-test. Cell Counting Kit-8 (CCK-8), flow cytometry and in vivo tumor formation assays were used to assess cell proliferation, apoptosis and tumorigenesis, respectively. Interaction between STMN1 and Yes associated protein (YAP1) was determined by immunoprecipitation (IP) and immunofluorescence technologies. RESULTS The results showed that STMN1 expression in liver cancer tissues was significantly higher than that in the adjacent normal tissues and increased STMN1 expression predicted an advanced clinical process and short overall survival of patients. Cell proliferation was increased and apoptosis was decreased when STMN1 was upregulated in HepG2 and SNU-398 cells. Besides, our results demonstrated that the overexpression of STMN1 enhanced the tumorigenesis of liver cancer cells through upregulating YAP1. CONCLUSIONS The current study demonstrates that STMN1 upregulation promotes the occurrence and development of liver cancer via activating YAP1 signaling. STMN1 overexpression may be an early event of liver carcinogenesis and it may be served as a marker for the diagnosis and treatment of liver cancer.