Molecular Evaluation of TNF-α-308 and TNF-α-238 Polymorphisms and Their Association with HPV Genotypes in Cervical Lesions

Background: Cervical cancer is a multi-stage disease caused by a DNA virus and is involved in one or more stages of the pathogenesis process. In addition to human papillomaviruses (HPV), the tumor necrosis factor-α gene (TNF-α) is considered a major intermediate mediator of the acute inflammatory response to viruses and gram-negative bacteria. The pro-region polymorphisms of the TNF-α gene, such as -308 and -238 polymorphisms, affect the expression of this gene. Therefore, this study aimed to investigate the polymorphisms of the TNF-α gene and their relationship with various genotypes of HPV in cervical lesions. Methods: In this study, 58 female patients with cervical cancer symptoms were selected. Following histopathologic studies, DNA was extracted from all specimens, and the PCR method was used to determine the types of HPV genotypes and TNF-α gene polymorphisms. An ARMS-PCR reaction was also performed to amplify TNF-α -308 and TNF-α -238 polymorphisms. Statistical analysis of the data was carried out using Epi Info software version 7.2 and the Chi-Square (χ²) test with SPSS ver. 7.3.1.10. These lesions were categorized into metaplasia groups (93.37%), cervical intraepithelial neoplasia (CIN) I and II (20.68%), CIN III (15.51%), and squamous cell carcinoma (SCC) (25.86%). Results: A total of 58 lesions were collected, of which 26 were HPV positive. They were categorized as follows: 1 sample (4.53%) metaplasia, 7 samples (33.58%) CIN I and II, 6 samples (66.66%) CIN III, and 12 samples (80%) SCC. Statistical analysis showed a significant difference between different types of HPV genotypes in different stages. On the other hand, unlike the -238 polymorphism of the TNF-α gene, a significant difference was observed between the various types of -308 polymorphism of the TNF-α gene in the three groups of metaplasia, CIN, and SCC. In general, it can be concluded that GG genotype testing of the -308 polymorphism of the TNF-α gene, combined with HPV types and para-clinical parameters, can be effective as risk factors and molecular markers for prognosis and early treatment of cervical cancer. Discussion: Consistent with other studies, this study demonstrated that about 80% of cervical cancer lesions had HPV presence. HPV subtypes 18 and 31 were more frequently associated with malignancy progression, while HPV-33 and HPV-35 subtypes did not show a significant association with malignancy progression. However, in other female populations in Iran, diverse results were reported. In the current study, it was shown that in TNF-α -308 polymorphism, the A allele accounted for the highest frequency (63.63%) in the metaplasia (control) group, while the GG allele was more frequent in the CC group. In general, the frequency of the A allele varies across different countries.