CypA is the most important member of Cyclophilins. It is a widely expressed protein in nature possessing PPIase and chaperone activities which help the precise folding of protein. Also, it is involved in immunosuppression, inflammation and the balance of cholesterol. As the understanding of CypA function has deepened, people began to realize that there might exist a relationship between CypA and cancer. Lung cancer is the first carcinoma which was found as expressing high level of CypA. CypA plays the roles in increasing proliferation, antiapoptosis, invasion and metastasis in lung cancer. The study of CypA may open a new window for the early diagnosis, prognosis and novel therapeutic drugs targeting.
亲环素A（cyclophilin A, CypA）作为亲环素家族中最重要的一员，在自然界中广泛表达，发挥着肽基脯氨酰顺反异构酶（peptidyl-prolyl cis-trans isomeras, PPⅠase）活性和分子伴侣效应，辅助细胞内蛋白质的正确折叠，参与免疫抑制，介导炎性反应，平衡细胞内外胆固醇。随着对CypA认识的加深，人们逐渐意识到它与恶性肿瘤之间的密切联系。CypA最先被发现在肺癌中高表达，具有促进肺癌细胞生长、抑制凋亡、介导侵袭转移等作用，可能成为一个肺癌的早期诊断和治疗的新靶点。