Abstract
AIMS: To clone and express Siva1 protein, and to investigate the role of Siva1 protein in proliferation, apoptosis, invasion, and migration of human nasopharyngeal carcinoma cell line CNE-2 in vitro and in vivo. METHODS: The PCR fragment of Siva1 from human nasopharyngeal carcinoma cell line CNE-2 were double digested with BamHI and SalI and then induced into the pQE30 vector double digested by the same enzymes. The pQE30 vector harboring Siva1 was introduced into M15 competent cells and then induced by isopropyl β -D-1-thiogalactopyranoside (IPTG). The Siva1 fusion protein was identified by 12% sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and then separated and purified by Ni-affinity chromatography. Subsequently, the effects of recombinant Siva1 protein on proliferation, apoptosis, invasion and migration were assayed in vitro and in vivo. RESULTS: The transformed cells expressed Siva1 fusion protein with a molecular weight of approximately 12 kDa. Cell counting kit-8 (CCK-8) assay showed that the Siva1 protein significantly inhibited the proliferation of the CNE-2 cells at a concentration of 10 μ mol/L. In addition, compared to the control, the Siva1 protein promoted the apoptosis of the cancer cells. And, the Siva1 protein greatly suppressed the invasion and migration of the cancer cells. In vivo, the Siva1 protein significantly inhibited the tumor growth of the tumor-bearing mice. Further, the Siva1 treatment markedly upregulated Bax, caspase-3, and downregulated Bcl-2 protein levels in the transplanted tumor tissue. CONCLUSIONS: The Siva1 protein has a significant anticancer activity on human nasopharyngeal carcinoma cell line CNE-2 including inhibiting proliferation, invasion, migration and promoting apoptosis of the cancer cells.