Carcinogenesis：葡萄籽抽提物杀死头颈部癌细胞

Generation of reactive oxygen species by grape seed extract causes irreparable DNA damage leading to G2/M arrest and apoptosis selectively in head and neck squamous cell carcinoma cells

Sangeeta Shrotriya, Gagan Deep, Mallikarjuna Gu, Manjinder Kaur, Anil K. Jain, Swetha Inturi, Rajesh Agarwal and Chapla Agarwal

Head and neck squamous cell carcinoma (HNSCC) accounts for 6% of all malignancies in United States, and unfortunately, the recurrence of secondary primary tumors and resistance against conventional treatments decrease the overall 5-year survival rate in HNSCC patients. Thus, additional approaches are needed to control HNSCC. Here, for the first time, employing human HNSCC Detroit 562 and FaDu cells as well as normal human epidermal keratinocytes (NHEK), we investigate grape seed extract (GSE) efficacy and associated-mechanism in both cell culture and nude mice xenografts. GSE selectively inhibited the growth, and caused cell cycle arrest and apoptotic death in both Detroit 562 and FaDu cells by activating DNA damage check-point cascade including ATM/ATR-Chk1/2-Cdc25C as well as caspases 8, 9 and 3. Consistent with these results, GSE treatment resulted in a strong DNA damage, and a decrease in the levels of DNA repair molecules Brca1 and Rad51 and DNA repair foci. GSE-caused accumulation of intra-cellular reactive oxygen species (ROS) was identified as a major mechanism of its effect for growth inhibition, DNA damage and apoptosis, which was remarkably reversed by antioxidant N-acetylcysteine. GSE feeding to nude mice decreased Detroit 562 and FaDu xenograft tumor growth by 67% and 65% (p<0.001), respectively. In IHC analysis, xenografts from GSE-fed groups showed decreased proliferation but increased DNA damage and apoptosis. Together, these findings show that GSE targets both DNA damage and repair, and provide mechanistic insights for its efficacy selectively against HNSCC both in cell culture and mouse xenograft; supporting its translational potential against HNSCC.