The Role of p53 Gene in Cervical Carcinogenesis

J Obstet Gynaecol India. 2016 Oct;66(Suppl 1):383-8. doi: 10.1007/s13224-015-0754-1. Epub 2015 Sep 4.

Abstract

Aim: To investigate the role of p53 gene in cervical carcinogenesis.

Materials and methods: A total 50 cases and controls were taken after setting exclusion criteria. Venous blood (3 ml) samples were collected in sterile EDTA sterile vials. Both punch biopsy of cervical growth in cases and biopsy from cervix after hysterectomy in controls were performed. Genomic DNA was extracted from tissue and blood using standard protocol of Miller et al. 1994 using chloroform-phenol method. Gene was amplified using specific forward and reverse primers and p53 gene expressions were studied. The present study of p53 gene regulation analyzed the expression of 279-bp bands on 1.5 agarose gel.

Observations: Out of the total 50 samples of cases and controls, we were able to isolate DNA from 38 cases and 28 controls in blood and in 22 cases and 22 controls in tissue. In cases of carcinoma cervix, p53 expression is either downregulated or absent in 71.06 % of cases compared to 50 % of controls in blood and 72.73 % of cases compared to 59.09 % of controls in tissue, but these figures were not statistically significant (p = 0.67 and p = 0.167, respectively). p53 positivity rate was only in 27.78 % of squamous cell cancer and 50 % of adenocarcinoma. Three out of nine patients (33.3 %) with L.N. positive status have p53 gene positivity, whereas 23 % (3 out of 13) with L.N. negative status have p53 gene positivity, which is not significantly associated. In our study, p53 overexpression increases with the various stages of cervical cancer.

Conclusion: In our study, we found that there is the increased frequency of upregulation or overexpression of p53 gene in control in both blood (50 %) and tissue (40.9 %), but this association is statistically nonsignificant. In the present study, there is a lack of relationship between p53 overexpression and prognosis in the cervical cancer patients. However, our study lacked larger sample size which otherwise would have been able to lend support to truly significant findings through much larger combined and comparative datasets.

Keywords: Cervical cancer; PCR; p53 gene expression.