肺炎衣原体（Chlamydia pneumoniae，Cpn）是人类致病性衣原体。Cpn通过口腔、鼻粘膜侵入人体，寄生于黏膜上皮细胞和肺泡上皮细胞，从而感染肺泡巨噬细胞。血清流行病学研究表明，慢性Cpn感染与肺癌有关，但其机制不明。全基因组测序结果表明，Cpn具有甲基化酶，其感染可能导致人类基因组DNA甲基化异常，Cpn感染可能导致人类基因组DNA甲基化异常，参与肺癌进展。本课题基于Cpn感染可造成健康人群的全基因组DNA甲基化水平差异，通过寻找Cpn感染相关肺癌病例与对照之间的甲基化差异表达，筛选出与肺癌发生发展密切关联的潜在生物标志物，并扩大样本验证其中的1-3个目标基因，探讨与环境因素交互作用对肺癌的影响，进行肺癌早期诊断，以期为Cpn与肺癌关系研究和肿瘤分子流行病学的临床转化提供科学依据。

Chlamydia pneumoniae (Cpn) is a kind of human pathogenic chlamydia. Cpn invade the human body by the mouth and nasal and are parasitic in epithelial cells and alveolar epithelial cells, and then infect alveolar macrophages. Seroepidemiology studies had shown that there are some relationships between the chronic infection of Cpn and lung cancer, but the specific mechanism is not clear. Whole genome sequencing results showed that Cpn can be as methylase, which may lead to acquire abnormal methylation in human genome and this may related with lung cancer. Based on the suppose that there will be differences of the genome-wide DNA methylation level between the healthy people with and without Cpn infection, we will collect the blood specimens from Cpn-related lung cancer patients and controls to analysis the DNA methylation of genome-wide, screen the potential biomarkers for Cpn-related lung cancer and then, we will choose 1-3 genes to verify and investigate their interactions with environmental factors. We hope that we will research the relationship between Cpn and lung cancer and provide the scientific basis for molecular epidemiology and clinical transformation.