Nitric Oxide Synthase Activity in Primary Non-small cell lung carcinoma

초록

Nitric oxide synthases (NOS) exist in human tumor cell lines and solid tumor tissues and it has been suggested that NO may play an important role in growth, progression or metastasis of tumors. We have investigated the distribution of NOS in 40 cases of primary non-small cell lung cancer and normal lung tissue. Immunohistochemical staining was performed with three monoclonal antibodies (iNOS, eNOS, nNOS). All forms of NOS were expressed in normal human lung epithelial cells and the immunoreactivity was predominantly found in the cytoplasm of the tumor cells. Surgical samples were classified into two categories according to the intensity and the percentage. Sixteen of 20 adenocarcinomas and 7 of 20 squamous cell carcinomas showed high iNOS immunoreactivity.Sixteen of 20 adenocarcinomas and sixteen of 20 squamous cell carcinomas showed high eNOS immunoreactivity. All 40 lung carcinomas showed high nNOS immunoreactivity. The clinicopathologic parameters such as age, sex, smoking history, histologic grade, and TNM classification did not correlate with NOS activity. The iNOS immunoreactivity in adenocarcinomas was significantly higher than squamous cell carcinoma (p=0.004). These results suggest that NO, especially induced by iNOS, may play an important role in carcinogenesis of lung adenocarcinoma.