HPV16 E6 mutations and p53 codon72 polymorphism among women with cervical intraepithelial neoplasia 2 and 3 in China

Objective: To study the distribution of HPV16 E6 gene mutations and p53 codon72 polymorphism among women with HPV16+ cervical precancerous lesions and explore their relationship with the risk of cervical intraepithelial neoplasia (CIN) 2, 3. Materials and Methods: This study analyzed a total of 112 cases of exfoliated HPV16+ cervical cell specimens which were divided into group 1 (normal and CIN1, 55 cases) and group2 (CIN2, 3, 57 cases). Among the 112 specimens, 85 cases were successfully amplified for HPV E6 gene by PCR and the PCR products were sequenced directly. P53 codon72 region was also amplified from the 112 specimens and the PCR products were sequenced directly and compared with the standard sequence. Results: Among the 85 amplified HPV sequences, point mutations such as T178G, T350G, G132A, A442C, T310G, G94T, C551A, etc. were found, among which, T178G showed the highest rate (51.76%). The rate of HPV16 E6 mutation T178G in CIN2, 3 group was significantly higher than that in normal and CIN1 group, i.e., in the 112 amplified p53 codon72 sequences, the distribution of Pro/Pro genotype in normal, and CIN1 group was significantly different from that in CIN2, 3 groups, and the disease risk of Pro/Pro genotype was much higher than that of Arg/Arg and Arg/Pro genotypes. Conclusion: HPV16 E6 T178G mutation increases the disease risk of CIN2, 3. Meanwhile, compared with Arg/Arg and Arg/Pro genotypes, p53 codon72 Pro/Pro genotype more associated with the disease risk of CIN2, 3.