Objectives: The methylation profile of genes in precursor lesions in cervical cancer was characterized to improve screening techniques for high-grade intraepithelial neoplasia.
Methods: A total of 447 cervical cytology samples obtained from women who underwent colposcopy were examined. The cases were distributed as follows: (1) cervices without cervical intraepithelial neoplasia (CIN; n = 152); (2) cervices with a CIN grade of 1 (CIN 1; n = 147); and (3) cervices with a CIN grade of 2 or 3 (CIN 2/3; n = 148). The methylation pattern for a panel of 15 genes was analysed by quantitative methylation-specific PCR (qMSP) and compared between the groups (≤CIN 1 vs. CIN 2+).
Results: In the validation set, seven genes presented significantly different methylation profiles according to diagnosis, namely, DAPK1 (p = 0.001), EPB41L3 (p = 0.001), HIC1 (p = 0.028), hsa-miR-124-2 (p = 0.001), LMX1A (p = 0.001), SOX1 (p = 0.001), and TERT (p = 0.001). Six genes showed a significant increase in the frequency of methylation in the presence of hr-HPV, namely, DAPK1 (p = 0.001), EPB41L3 (p = 0.001), hsa-miR-124-2 (p = 0.001), LMX1A (p = 0.001), SOX1 (p = 0.001), and TERT (p = 0.001). The methylation of the hsa-miR-124 gene showed sensitivity and specificity (86.7% and 61.3%, respectively) similar to that of the HPV test (91.3% and 50.0%, respectively). The independent factors associated with the diagnosis of CIN 2+ and the methylation of the hsa-miR-124-2 (OR = 5.1), SOX1 (OR = 2.8), TERT (OR = 2.2), and LMX1A (OR = 2.0) genes were a positive test for hr-HPV (odds ratio [OR] = 5.5).
Conclusions: Hypermethylation of the hsa-miR-124-2, SOX1, TERT, and LMX1A genes may be a promising biomarker for precursor lesions in cervical cancer regardless of the hr-HPV status.
Keywords: Cervical cancer prevention; Cervical cytology; Cervical intraepithelial neoplasia; DNA methylation; Human papillomavirus; Tumour suppressor genes.
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