Transcriptional changes of BAX and BCL-2 genes under the effect of vitamin E in colon cancer cell line (HT29)

Despite significant advances in cancer diagnosis and treatment, cancer is still a fatal disease due to lack of prevention, early detection and effective drugs. Therefore, there is a need to discover anticancer treatments that are specific to cancer cells and are affordable, safe and tolerable for patients. Vitamin E is a potential candidate because of its safety. A growing body of evidence on the anticancer power of vitamin E has shifted the focus away from chemical drugs and antioxidants. The purpose of this study is to investigate the effect of vitamin E on the survival of colorectal cancer cell lines and the effect of this vitamin on two important genes involved in apoptosis. MTT test was performed on this cell line treated with different concentrations of vitamin E (500 to 33350 μg/ml). After determining the IC50 of this vitamin, RNA was extracted from cells treated with vitamin E and untreated cells and then cDNA synthesis was performed. Using the specific primers of BAX and BCL2 genes and considering the GAPDH gene as the reference gene, Real time PCR was performed and the results were analyzed. MTT test showed that vitamin E in low concentrations strengthens and increases the survival of HT29 cell line, but at a concentration of 10000 μg/ml, it decreases the survival percentage of this cancer cell line. Analysis of gene expression also showed that vitamin E leads to increased transcription of both BAX and BCL2 genes. But the increase in BCL2 transcription is several times higher than that of BAX. In general, the cytotoxicity and lethality of vitamin E on colorectal cancer cell line was proved and it was found that this toxicity is not through Bax and Bcl-2 genes and probably the apoptotic effect of this vitamin is through other ways such as reducing survivin expression.