Alsterpaullone induces apoptosis of HepG2 cells via a p38 mitogen-activated protein kinase signaling pathway

Alsterpaullone (Alp) is a small-molecule inhibitor that targets cyclin-dependent kinases to inhibit tumor cell activity. However, to the best of our knowledge, the effect of Alp on hepatoblastoma has not been investigated. Therefore, the function of Alp in apoptotic induction of hepatoblastoma cells and a potential mechanism of action were investigated. Results indicated that low doses of Alp (1 mu M) significantly induced apoptosis in the HepG2 hepatoblastoma cell line. In vivo experiments of tumor suppression further indicated that Alp (3 mg/kg) exerted an inhibitory effect on HepG2 xenograft tumor growth. Following Alp treatment, the expression level of B-cell lymphoma 2 (Bcl-2)-associated X protein, and cleaved caspase-3 and -9 in HepG2 cells was significantly increased; however, the expression of Bcl-2 was significantly decreased. In addition, phosphorylation of p38 mitogen-activated protein kinase (MAPK) significantly decreased Alp-induced caspase-3 and -9 activation. These results suggested that Alp induces apoptosis and inhibited proliferation via the p38(MAPK) signaling pathway. Therefore, Alp may be a therapeutic agent for treating hepatoblastoma.