Effect of LHX2 gene methylation level and its function on radiotherapy of cervical cancer

BACKGROUND: Cervical cancer is the most common malignancy of the female reproductive system, for which radiotherapy is one of the main treatments. Gene methylation in cells is an important factor in tumorigenesis, and radiotherapy can change DNA methylation in cells. At the same time, combined with the clinical effect of radiotherapy, key genes of LIM homeobox 2 (LHX2) significantly related to cervical cancer. The LHX2 are LIM-homeobox genes that play important roles in signal transduction, cell differentiation, tissue-specific differentiation, and body formation. METHODS: In this study, bisulfite genomic sequencing (BSP-Seq) technology was used to analyze the methylation level of LHX2 in patients with cervical cancer before and after radiotherapy. In addition, combined with the clinical effect of radiotherapy, the function of LHX2 in siHA and C33A cells were analyzed with the help of overexpression, small interfering RNA (siRNA), cell invasion, and migration ability. The expression level of the migration- and apoptosis-related genes which were affected by LHX2 were tested with quantitative real time polymerase chain reaction (qRT-PCR). RESULTS: Combined with clinical treatment, methylation level difference, and correlation enrichment analysis, it was found that LHX2 genes were closely related to the occurrence and development of cervical cancer. After 5-aza-2’-deoxycytidine (5-Aza-dC) and radiotherapy, the methylation of LHX2 genes in siHA and C33A squamous cell carcinoma cells was decreased, and the messenger RNA (mRNA) and protein expression levels were relatively increased; meanwhile, the LHX2 could accelerate the ability for cell invasion and migration and inhibited the apoptosis of the cell after treatment with radiotherapy. CONCLUSIONS: The methylation and expression levels of LHX2 genes are closely related to cervical cancer. The methylation level of LHX2 was reduced after radiation therapy. The LHX2 gene has a positive effect on cervical cancer through acceleration of the cell invasion and migration ability and inhibition of cell apoptosis after radiotherapy treatment.