Apoptosis induction in ascorbic acid treated human colorectal cancer cell lines (Caco-2)
Nada N. Mustafa, Mohamed A. El-Desouky, Nessreen A. Shawush, Demiana H. Hanna
Abstract
The current study aims to study the therapeutic effects of ascorbic acid on Caco-2 cancer cell inhibitory mechanisms. The cytotoxicity of ascorbic acid on Caco-2 cells was determined by MTT and LDH assays. Also, apoptosis induction in ascorbic acid-treated Caco-2 cells was tested through annexin and DNA fragmentation techniques. Cell cycle arrest, ROS generation, RT-PCR, and western plot analyses were conducted to identify the apoptosis mechanisms of Caco-2 cells after treatment with ascorbic acid. According to the data, ascorbic acid demonstrated selective efficacy in inhibiting Caco-2 cell growth, with the most effective IC50 value (53.6 μg/ml) attained after 48 hours of incubation. Also, compared to the untreated control cells, the ascorbic acid-treated Caco-2 cells displayed a much higher rate of LDH leakage. Additionally, the ascorbic acid IC50 value found a considerable rise in early and late apoptotic Caco-2 cells with an intensive comet nucleus as a marker of DNA fragmentation. Moreover, flow cytometry analysis of the apoptosis process in Caco-2 treated cells revealed cell cycle arrest in the S phase with an increase in apoptotic cells in the sub-G1 phase. Also, real-time PCR and Western blot analysis showed that ascorbic acid significantly changed protein expression levels linked with cell cycle arrest in the S phase and the induction of apoptosis. Consequently, our data indicated that ascorbic acid would be a promising therapy candidate for colon cancer in people.