CHD5 is a potential tumor suppressor in non small cell lung cancer (NSCLC)

Lung cancer is one of the deadliest types of cancers and genetic and epigenetic alterations play major roles in its development. Chromodomain (CHD) protein family acts in chromatin organization, regulation of transcription and also genomic stability and cancer prevention. Although CHD5, a member of this family was shown to contribute to major cellular events and functions as a tumor suppressor gene in various types of cancer, it is not clear whether CHD5 plays a role in lung carcinogenesis. The aim of this study was to investigate the possible role of CHD5 in progression of non-small cell lung cancer (NSCLC). Expression levels of CHD5 gene in 59 tumor and corresponding non-cancerous lung tissue samples were analyzed by qRT-PCR and the methylation status of the promoter region was investigated by methylation specific PCR (MS-PCR). The Akt phosphorylation levels were investigated by Western Blot (WB). CHD5 was down-regulated in 17 (39.5%) and up-regulated in 24 (55.8%) of tumor specimens. Even though the promoter of CHD5 was hypermethylated in 8 patients, it was not found associated with CHD5 gene expression (p=0.08). Akt phosphorylation was increased in 14 (53.8%) and decreased in 12 (46.2%) of the samples but no significant association was found between p-Akt phosphorylation and CHD5 expression (p=0.67). We suggest that CHD5 may act as a tumor suppressor gene in NSCLC.