Penicilazaphilone C, a new azaphilone, induces apoptosis by blocking the Notch signalling pathway in gastric cancer

ABSTRACT

Objective: To explore the molecular mechanisms of the anticancer activities of penicilazaphilone C against gastric cancer. Methods: In vitro effects of penicilazaphilone C on cell growth, proliferation, and apoptosis were evaluated by MTT, BrdU, MTS, colony formation assays, Hoechst 33258 staining, and flow cytometry. Related proteins were examined by Western blotting assays. The expression of Notch receptor was analyzed using real-time PCR. In vivo antitumor activities of penicilazaphilone C were observed in nude mice. Results: Compared to the controls, penicilazaphilone C suppressed cell proliferation and promoted apoptosis in MGC-803 and SGC-7901 cells. The Notch/PTEN/AKT axis was involved in the activating penicilazaphilone C-induced apoptosis. Penicilazaphilone C decreased levels of Notch, NICD, phospho-PTEN and phospho- AKT compared to controls. The penicilazaphilone C-induced inhibition of Notch-related protein expression levels and the resulting apoptosis could be reversed by overexpression of Notch1 or/and Notch2. Moreover, penicilazaphilone C inhibited tumor growth in mice bearing tumours derived from MGC-803 and SGC-7901 cells, respectively. Conclusions: Penicilazaphilone C can induce the apoptosis by suppressing the activation of the proteolytic cleavage of the Notch receptor and subsequently blocking the PTEN/AKT signaling axis in gastric cancer cells. Thus, penicilazaphilone C is a potential alternative agent for the treatment of gastric cancer.