Detecting the expression of MRP-1/CD9 in lung cancer using tissue microarrays

Objective MRP-1/CD9 is one member of transmembrane 4 superfamily. It has been reported to be associated with motility-suppression. The aim of this study was to investigate its expression in lung cancer and the relationship between its expression and pathologic grades, clinical stages, metastasis, prognosis. Methods To observe MRP-1/CD9 protein expression, tissue microarray (TMA), which contained 54 diseased tissues of lung cancer and 10 normal tissues of lung was prepared and performed using immunohistochemistry (IHC). The statistical method was χ 2 analysis. The difference was considered significant as P 0.05.Results The positive rate of MRP-1/CD9 expression was 42.60% in lung cancer, lower than that of normal lung tissues. The statistical difference was significant ( P 0.05). Its protein expression had no relationship with the patients' age, sex and the macroscopic type of tumor, but it had relationships with the histological type, clinical stage, differentiated degree and metastasis. The expression of non-small cell lung cancer(NSCLC) was higher than that of small cell lung cancer(SCLC);The well-moderately differentiated group was higher than poorly differentiated group; Earlier period group (Ⅰ+Ⅱ) was higher than the later period group (Ⅲ+Ⅳ); The group without lymphnode metastasis was higher than that with lymphnode metastasis, above all had the significant meaning ( P 0.05). Conclusion The progression of the lung cancer may relate with the descended MRP-1/CD9 expression. The loss expression of MRP-1/CD9 in the small cell lung cancer was more important; The lower expression of MRP-1/CD9 promote the tumor's metastasis, this marker has hopes to become a new target to evaluate the tumor prognosis.