Anticancer Effects and Molecular Mechanisms of Gossypin on Phosphatidylinositol 3-Kinase/Protein Kinase B Inhibition in Human Nonsmall Cell Lung Cancer Cell Line, A549

Nonsmall cell lung cancer (NSCLC) accounts for approximately 80%-85% of all lung cancer patients. Gossypin, a flavonoid contained in Hibiscus vitifolius, has been reported as a potential anticancer agent. However, the effect of gossypin on NSCLC has not been elucidated. Herein, we evaluated the anticancer effects and investigated the molecular mechanisms of gossypin in NSCLC cell line, A549. We treated A549 cells with gossypin at different concentrations and performed cell viability and colony formation assays. As a result, gossypin inhibited cell proliferation. phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) is known to be involved in cancer cell growth. Additionally, p-PI3K/p-Akt reduces p21 expression, resulting in cell cycle progression. Therefore, the effects of gossypin on the expression of PI3K, Akt, and p21 were investigated via Western blot analysis. Gossypin inhibited p-PI3K/p-Akt and induced p21 expression. Also, gossypin induced the sub-G1 phase, which exhibits DNA fragmentation, indicating apoptosis. To corroborate these results, apoptosis and the expression of caspase-3 and poly ADP-ribose polymerase (PARP) were evaluated in gossypin-treated cells. Results showed that gossypin cleaved caspase-3 and PARP to induce apoptosis. Our study findings indicate a possible therapeutic effect of gossypin in NSCLC.