RESUMO
Cervical cancer is most familiar neoplasm among women worldwide. Surgery, radiotherapy, and chemotherapy are common treatments, however high stage tumors have frequently poor prognosis. HPV 16 and 18 are major etiological factors for cervical cancer. Likewise, epigenetics is the study of inherited changes and modulated gene expression without alteration in DNA sequences. In mammals epigenetic modifications include DNA methylation, histone modifications and miRNA. Phytochemicals are mainly contained in fruits, seeds, and vegetables as well as in foods supplements. Numerous dietary compounds exhibit potent anti-tumor activities through the reversion of epigenetic alterations associated to oncogenes activation and inactivation of tumor suppressor genes in cervical cancer cell lines SiHa and HeLa, demethylation of the tumour suppressor genes such as RARβ2, MGMT, RASSF1A, DAPK etc. Reversal of hypermethylated genes as a tumor-suppressor gene, is related to inhibition of cell proliferation, development and differentiation. The impact of phytochemicals lead to the reversal of hypermethylation which may help to cure cervical cancer. This study concludes the effect of phytochemicals on genetic and epigenetic modifications and reveals how these modifications help to prevent various types of cancers and improve health outcomes.
RESUMO
An important molecular target for cancer therapy is the possible reactivation of tumor suppressor genes that have been silenced by promoter methylation. It was observed that the treatment of an adenocarcinoma cervical cancer cell line, HeLa with 20 μg/ml of the ethanolic extract of Withania somnifera for 6 days resulted in demethylation of promoter of RARβ2 gene. However, treatment with Ocimum sanctum and Azadirachta indica (20μg/ml) did not cause the reversal of hypermethylation after 6 days of treatment. This is the first report to show the reversal of hypermethylation of RARβ2 gene by Withania somnifera extract in a cervical cancer cell line.