Association of NK6 homeobox 1 promoter methylation with HPV infection, histological sub-type, and patient outcomes in cervical lesions.

OBJECTIVE

To evaluate NK6 homeobox 1 (NKX6.1) promoter methylation in cervical lesions and its association with human papillomavirus (HPV)16/18 infection, histological sub-type, and patient outcomes using clinical and bioinformatic data.

METHODS

A total of 207 cervical tissue samples, including cervicitis (n = 22), cervical intraepithelial neoplasia grade 3 (n = 20), adenocarcinoma in situ (n = 6), adenocarcinoma (n = 59), and squamous cell carcinoma (n = 100), were analyzed by methylation-specific polymerase chain reaction and bisulfite sequencing. HPV genotyping was performed with the INNO-LiPA assay. The Cancer Genome Atlas data (n = 309) were examined for methylation at 27 cytosine-phosphate-guanine sites and their association with overall survival.

RESULTS

NKX6.1 promoter methylation was detected in 26.6% of cervical samples and was significantly associated with neoplastic lesions, particularly squamous sub-types (p = .002), with comparable frequencies in cervical intraepithelial neoplasia 3. Logistic regression confirmed that NKX6.1 methylation and HPV16/18 infection were independently associated with squamous cell carcinoma. The Cancer Genome Atlas analysis revealed 11 cytosine-phosphate-guanine sites within NKX6.1 significantly correlated with overall survival, with loci, such as cg12401926 and cg18297736 linked to poorer outcomes. These prognostic effects were locus-specific and not observed when global methylation was considered.

CONCLUSION

NKX6.1 promoter methylation represents an early event in cervical carcinogenesis and is associated with squamous histology. Although global methylation showed no prognostic relevance, site-specific cytosine-phosphate-guanine methylation patterns demonstrated significant survival associations, supporting NKX6.1 as a potential locus-dependent prognostic biomarker in cervical cancer.