Identification of <i>ALX3</i> Gene Promoter Hypermethylation as a Potential Biomarker for Lung Cancer

Background/Aim: Recent studies imply the significance of promoter CpG methylation as a biomarker for various cancer types in different genes. ALX3 is one of the candidate genes with prominent promoter methylation status change. In this study, the methylation status of ALX3 gene promoter and its expression was analyzed in lung cancer cell lines and clinical samples from The Cancer Genome Atlas Program (TCGA) program. Materials and Methods: Methylation status was screened using the COBRA Assay, and gene expression in two cancer (A549 & H1299) and one normal (Beas 2B) lung cell lines was determined using RT-PCR. Results: ALX3 gene promoter was found to be hypermethylated in both lung cancer cell lines compared to normal cells. However, no difference in the expression of this gene was observed. In addition to our in vitro findings, DNA Methylation and RNA-seq data of 413 adenocarcinoma samples from TCGA-LUAD dataset were analyzed. ALX3 gene was found to be hypermethylated in tumor compared to normal samples. Interestingly, the expression level of ALX3 gene in tumors was found to be higher than that in normal samples. Conclusion: ALX3 gene promoter hypermethylation could serve as a biomarker in lung cancer.