Down-regulation of testes-specific protease 50 induces apoptosis in human laryngocarcinoma HEp2 cells in a NF-κB-mediated pathway

Testes-specific protease 50 is a newly reported threonine enzyme. It has similar amino acid sequences and enzymatic structures to some other serine proteases. It is proposed as a laryngocarcinoma-related gene in human beings. The physiological mechanism by which TSP50 exerts its promoting effects in laryngocarcinoma is not yet fully understood. The study investigated the function of TSP50 by suppressing its expression in the HEp2 cell line using a TSP50-specific short hairpin RNA (shRNA). Western bloting and real-time-PCR were used to detect the levels of TSP50. By using MTT, Wound healing, flow cytometric and tumorigenesis assays, the study tested the TSP50 role in human laryngocarcinoma cell growth and apoptosis. The results demonstrated that TSP50 knockdown could inhibit HEp2 cell proliferation and induce apoptosis in vitro in a NF-κB-mediated pathway. The tumorigenicity of TSP50 shRNA-expressing cells were decreased after inoculating into nude mice. The present results provide a new understanding of the TSP50 gene in the progression of laryngocarcinoma and put up a novel therapeutic target for treating this cancer.