Gossypin induces apoptosis and autophagy via the MAPK/JNK pathway in HT‑29 human colorectal cancer cells.

Abstract

Gossypin, a flavone found in Hibiscus vitifolius, exhibits antioxidant, antidiabetic, anti‑inflammatory and anticancer effects. The present study investigated the potential of gossypin to induce apoptosis and autophagy in HT‑29 human colorectal cancer (CRC) cells, and assessed its association with the MAPK/JNK pathway. Cell viability assays, DAPI staining, flow cytometry, acridine orange staining, western blotting, hematoxylin and eosin staining, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining and immunohistochemistry were performed. The results revealed an increased number of apoptotic bodies, higher apoptosis rates and enhanced autophagy in gossypin‑treated HT‑29 cells. To investigate autophagy during cell death, the effects of the early autophagy inhibitor 3‑methyladenine (3‑MA) and the late autophagy inhibitor hydroxychloroquine on cell viability and the expression of apoptosis‑related proteins were assessed. Significant increases in cell viability were observed following 3‑methyladenine pretreatment, as well as a decrease in the expression levels of Bcl‑2 and an increase in Bax. The analysis of MAPK pathway proteins following treatment with gossypin revealed that the levels of phosphorylated (p‑)JNK and p‑p38 were significantly increased in a concentration‑dependent manner. The JNK inhibitor SP600125 was used to confirm the role of the JNK pathway in gossypin‑induced apoptosis and autophagy. Moreover, gossypin reduced the volume of HT‑29 tumors in mice, and western blotting indicated the induction of apoptosis and autophagy in these tumors in vivo. Finally, TUNEL and immunohistochemistry experiments confirmed the induction of apoptosis and p‑JNK upregulation in these tumors in vivo. In conclusion, the present study suggested that gossypin may induce MAPK/JNK‑mediated apoptosis and autophagy in HT‑29 CRC cells, highlighting the potential of gossypin as an anticancer agent.