Abstract: ObjectiveTo investigate the expression of potassium inwardlyrectifying channel subfamily J member 15 （KCNJ15） in lung adenocarcinoma tissues and its effect on proliferation and migration of lung adenocarcinoma A549 cells. 
MethodsA total of 117 lung cancer tissues and 50 paracancerous tissues were collected from July 2006 to October 2015 in our hospital. The mRNA levels of KCNJ15 in the above tissues were detected by realtime quantitative PCR， and the relationship between the mRNA level of KCNJ15 in the lung adenocarcinoma tissues and the clinicopathological parameters （sex， age， tumor size， clinical stage， tumor location， lymph node metastasis and pathological grade） was analyzed. The prognosis of different KCNJ15 mRNA levels was analyzed according to the followup data. The overexpression vector of KCNJ15 was constructed and transfected into A549 cells. The function of KCNJ15 gene on proliferation and migration of A549 cells was analyzed by CCK8 and Transwell assay. 
ResultsThe mRNA level of KCNJ15 gene in lung adenocarcinoma tissues was significantly lower than that of paracancerous tissues （P＜005）. The expression of KCNJ15 gene was related to the size and clinical stage of the lung adenocarcinoma （P＜005）， but not related to age， pathological grade， sex， lymph node metastasis and tumor location （P＞005）. The overall survival of the lung adenocarcinoma patients with high expression of KCNJ15 was longer than patients with low expression. The results of the acquired functional experiment showed that the overexpression of KCNJ15 gene could inhibit the proliferation and migration of lung adenocarcinoma cells. 
ConclusionThe expression of KCNJ15 gene in lung adenocarcinoma is obviously decreased. Its expression is related to the size and clinical stage of lung adenocarcinoma. It is an important prognostic marker in the survival of the patients with lung adenocarcinoma， and can be used as a potential new target for the clinical treatment of lung adenocarcinoma.

Key words: Lung adenocarcinoma, Potassium inwardlyrectifying channel subfamily J member 15, Clinical significance, Proliferation and migration