Mutational Analysis Revealed Polymorphic Variants in Exon 3 and Exon 4 of p53 Gene in Cervical Cancer. Mutational Analysis

There is an increasing incidence and mortality rates from cervical cancer. Several risk factors contribute to the pathogenesis and progression of cervical cancer, chief among them include the sexually transmitted HPV infection, multiple sexual partners, poor attitude to screening and health intervention, late diagnosis, family history and many more. Genomic instability due to mutation in p53 gene has been attributed to several cancer cases. This research study explored the mutations in the exon 3 and exon 4 of the P53 gene in cervical cancer. Genomic DNA was isolated and purified from cervical tissue biopsies obtained from patients reporting at the University College Hospital, Ibadan. The purified genomic DNA was quantified using NanoDropTM 2000 spectrophotometer. The region of interest was amplified using Polymerase Chain Reaction (PCR), this was quantified on a 1.5% agarose gel, and the ethidium bromide stained gel was viewed on a transilluminator. The PCR products were sequenced at Inqaba Biotec, and chromatogram was analyzed using FinchTv. Nucleotide BLAST was performed on the DNA sequence for sequence identity and retrieval of reference sequence. Multiple Sequence Alignment using T-COFFEE was performed to reveal the polymorphic variations in the samples. The outcome of this study showed nineteen identified polymorphic variants; Missense mutations occurred in 47% of the samples, 32% were silent mutations, 16% were frameshift mutation and 5% nonsense mutation. Sociodemographic characteristics revealed that 60% of the study participants have husbands with multiple sexual partners and that only 23.3% of the participants have ever done pap smear test prior to diagnosis, while 20% of them are unaware of the screening test. The histopathological result, alongside the Multiple Sequence Alignment revealed that with higher severity of cervical carcinoma, the p53 gene tends to accumulate more mutations. Our study also revealed the poor knowledge of Nigerian women to cancer screening; this may be one of the contributory factors to late diagnosis of cervical cancer among the African population.