CHD5 downregulation associated with poor prognosis in epithelial ovarian cancer in Hong Kong Chinese women

Background: CHD5 gene located on 1p36, encodes a non-histone chromosomal protein, chromodomain helicase DNA binding protein 5. Recently, CHD5 has been shown to be a tumor suppressor gene candidate. This study was to investigate the involvement of CHD5 in epithelial ovarian cancer and its clinico-pathological significance. Methods: CHD5 expression in ovarian cancer and its normal counterpart was determined by quantitative RT-PCR. The methylation of CHD5 promoter was evaluated by methylation specific PCR. The correlation of CHD5 expression to patient age, tumor histological type and grade, clinical stage and status, recurrence and patient survival time was analyzed statistically. Results: CHD5 expression was down at least two-fold in 32 of 72 (41%) invasive epithelial ovarian carcinomas when compared to 12 normal controls in Hong Kong Chinese women. Hypermethylation in two promoter regions of CHD5 was not detected in any of the 20 tumor samples available to be analyzed. CHD5 down-regulation was correlated to clinical status (P 0.05). Kaplan-Meier survival analysis showed that patients with CHD5 down-regulation in their tumors were associated with shorter disease-free and total survival times compared to those without CHD5 down-regulation (P Conclusion: This preliminary study shows that CHD5 s down-regulated in a certain part of ovarian cancers and appears to be an adverse predictor candidate of ovarian cancer disease-free and total survival in Hong Kong Chinese women. If this role of CHD5 dysregulation can be confirmed in more prospective studies with a large number of patients, it is also worthwhile to further evaluate if CHD5 can be as an individualized molecular therapeutic target for epithelial ovarian cancer.