Correlation Analysis Of APC/PCDH20/RUNX3 Genes Methylation In Blood Between Lung Cancer And COPD In Yunnan Province

Chronic obstructive pulmonary disease(COPD)is a leading cause of morbidity and mortality worldwide.COPD and lung cancer share common environmental and genetic factors.Besides,the incidence rate of lung cancer is associated with COPD severity.In terms of epigenetic modifications,COPD and lung cancer has both commonness and difference.So,understanding the links of their epigenetic modifications and molecular mechanism will be a prerequisite for early risk evaluation or therapeutic interention in COPD patients with potential cancer risk.This study aims to study DNA methylation on candidate genes in groups of COPD,lung cancer,COPD with lung cancer,exploring the significance of DNA methylation in those genes for early diagnosis of lung cancer in COPD patients,and the possible common epigenetic changes that play a role in the pathogenesis of both lung cancer and COPD.Adenomatous Polyposis Coli(APC),Protocadherin 20(PCDH20)and Runt Related Transcription Factor 3(RUNX3),three tumor-suppressor genes,were chosen for searching for abnormal methylation markers in lung cancer and COPD.DNA methylation level were assessed by qMSP.Methods:Whole blood samples from 128 cases of patients with lung cancer or COPD in Yunnan Province were collected,including 11 cases only suffering from COPD,38 cases suffering from both COPD and lung cancer,79 cases only suffering lung cancer.Additionally,whole blood samples from 12 healthy persons were used for comparison.DNA methylation of three candidate genes(PCDH20,RUNX3,APC)were assesed by qMSP using in the whole blood samples.DNA methylation level among the patient groups of COPD,lung cancer,both COPD and lung cancer were analyzed.Results:On the levels of DNA methylation,patients suffering from both COPD and lung cancer are the highest for three patient groups in all three genes,APC,PCDH20 and RUNX3.There is significant difference between patients only suffering from lung cancer and only suffering from COPD;For methylation ratio,patients only suffering from lung cancer group have the highest in APC and PCDH20.The methylation ratio in gene RUNX3 in the only suffering from lung cancer group is slightly higher than those of the lung cancer group and both COPD and lung cancer group.Main conclusion:APC and PCDH20 genes can be seen as potential markers for lung cancer association in COPD.Besides,RUNX3 gene methylation level can also be considered as a reference gene for lung cancer association in COPD.