폐암에서 microRNA 155의 발현 양상과 임상병리학적 의의

Lung cancer is currently the most common malignant disease and the leading cause of mortality in the world and non-small cell lung cancer (NSCLC) accounts for 75-80% of lung cancer cases. miR-155 gene was found to be over expressed in several solid tumors, such as thyroid carcinoma, breast cancer, colon cancer, cervical cancer, pancreatic ductal adenocarcinoma (PDAC) and lung cancer. The aims of this study were to define the expression of miR-155 in lung cancer and its associated clinic-pathologic characteristics. Total RNA was purified from formalin-fixed, paraffin-embedded NSCLC tissues and benign lung tissues. Expression of miR-155 in human lung cancer tissues were evaluated as mean fold changes of miR-155 in cancer tissues compared to benign lung tissues by quantitative real-time reverse transcriptase polymerase chain reaction (real-time qRT-PCR) and associations of miR-155 expression with clinic-pathologic findings of cancer. Compared with the benign control group, miR-155 expression was significantly overexpressed in NSCLCs (p=<0.001). miR-155 was more overexpressed in squamous cell carcinoma than in adenocarcinoma. Poorly differentiated tumors showed significantly overexpression of miR-155 than well-differentiated tumors (p=<0.001). Overexpression of miR-155 was significantly associated with lymph node metastasis (p=<0.05). In survival analysis for all NSCLC patients, high miR-155 expression was significantly correlated with worse overall survival (p=<0.05). These results suggested that miR-155 might play an important role in lung cancer progression and metastasis.