Search

DNA topoisomerases are essential to modulate DNA topology during various cellular genetic processes. The expression and distinct prognostic value of topoisomerase isoforms in non-small-cell lung cancer (NSCLC) is not well established. In the current study, we have examined the mRNA expression of topoisomerase isoforms by using Oncomine analysis and investigated their prognostic value via the Kaplan–Meier plotter database in NSCLC patients. Our analysis indicated that the expression level of topoisomerases in lung cancer was higher compared with normal tissues. Especially, high expression of two topoisomerase isoforms, TOP2A and TOP3A, was found to be correlated to worse overall survival (OS) in all NSCLC and lung adenocarcinoma (Ade) patients, but not in lung squamous cell carcinoma (SCC) patients. In a contrast, high expression of isoforms TOP1 and TOP2B indicated better OS in all NSCLC and Ade, but not in SCC patients. Meanwhile, high expression of TOP1MT and TOP3B was not correlated with OS in NSCLC patients. Furthermore, we also demonstrated a relationship between topoisomerase isoforms and the clinicopathological features for the NSCLC patients, such as grades, clinical stages, lymph node status, smoking status, gender, chemotherapy and radiotherapy. These results support that TOP2A and TOP3A are associated with worse prognosis in NSCLC patients. In addition, our study also shows that TOP1 and TOP2B contribute to favorable prognosis in NSCLC patients. The exact prognostic significance of TOP1MT and TOP3B need to be further elucidated. Comprehensive evaluation of expression and prognosis of topoisomerase isoforms will be a benefit for the better understanding of heterogeneity and complexity in the molecular biology of NSCLC, paving a way for more accurate prediction of prognosis and discovery of potential drug targets for NSCLC patients. [ABSTRACT FROM AUTHOR]

PLA2G7 gene product is a secreted enzyme whose activity is associated with coronary heart disease (CHD). The goal of our study is to investigate the contribution of PLA2G7 promoter DNA methylation to the risk of CHD. Using the bisulphite pyrosequencing technology, PLA2G7 methylation was measured among 36 CHD cases and 36 well-matched controls. Our results indicated that there was a significant association between PLA2G7 methylation and CHD (adjusted P = 0.025). Significant gender-specific correlation was observed between age and PLA2G7 methylation (males: adjusted r = −0.365, adjusted P = 0.037; females: adjusted r = 0.373, adjusted P = 0.035). A breakdown analysis by gender showed that PLA2G7 methylation was significantly associated with CHD in females (adjusted P = 0.003) but not in males. A further two-way ANOVA analysis showed there was a significant interaction between gender and status of CHD for PLA2G7 methylation (gender*CHD: P = 6.04E−7). Moreover, PLA2G7 methylation is associated with the levels of total cholesterols (TC, r = 0.462, P = 0.009), triglyceride (TG, r = 0.414, P = 0.02) and Apolipoprotein B (ApoB, r = 0.396, P = 0.028) in females but not in males (adjusted P>0.4). Receiver operating characteristic (ROC) curves showed that PLA2G7 methylation could predict the risk of CHD in females (area under curve (AUC) = 0.912, P = 2.40E−5). Our results suggest that PLA2G7 methylation changes with aging in a gender-specific pattern. The correlation between PLA2G7 methylation and CHD risk in females is independent of other parameters including age, smoking, diabetes and hypertension. PLA2G7 methylation might exert its effects on the risk of CHD by regulating the levels of TC, TG, and ApoB in females. The gender disparities in the PLA2G7 methylation may play a role in the molecular mechanisms underlying the pathophysiology of CHD. [ABSTRACT FROM AUTHOR]