Knock-down of ABCE1 gene induces G1/S arrest in human oral cancer cells.

PURPOSE This study aims to explore the clinical characteristics of ATP binding cassette E1 (ABCE1) in oral squamous cell carcinomas (OSCC) and its roles in the proliferation, invasiveness, migration and apoptosis of the human oral squamous cell carcinoma cells CAL-27. METHODS The expression of ABCE1 and its target protein-RNase L, were first studied in tumor tissues of OSCC and adjacent non-tumor tissues. Moreover, CAL-27cells were transfected by ABCE1-specific shRNA, then MTT assay, the transwell and scratch assay were used to study cell proliferation and migration activity; the apoptosis rate and cell cycle distribution were tested by flow cytometry. Western blot and RT-PCR assay were adopted to measure their silencing efficacy. RESULTS ABCE1 expression is low in the adjacent non-tumor tissues while the expression is high in the oral cancer; the expression is reversely proportional to the differentiation degrees. The expression of RNaseL was in contrary to ABCE1. After transfected with ABCE1-siRNA, the proliferation, invasiveness and migration capabilities of cells decreased significantly whilst the apoptosis rate enhanced greatly (P < 0.01). Meanwhile, the expression of ABCE1 in CAL-27 cells was blocked (P < 0.01) while the expression of RNase L increased significantly (P < 0.01). CONCLUSION ABCE1 is closely connected with the pathogenesis and development of oral cancer, which acts through the cellular pathways of 2-5A/RNase L.