Expression And Clinical Significance Of Bmi-1 And P16INK4a In NSCLC

Objective To investigate the association between the expression of B cell-specific MLV integration site-1(Bmi-1) and P16^INK4a in NSCLC(no small cell lung cancer) and their clinicopathologic significance.Methods The samples of cancerous tissues and paracancerous tissues were collected from 20 patients with NSCLC.The expressions of Bmi-1 and P16^INK4a protein were determined by Western blot.The expression of Bmi-1 and P16^INK4a were detected by EnVision immunohistochemistry method in tissue microarray prepared from 130 NSCLC patients.Statistical analysis was performed to investigate the association between the clinicopathologic features and Bmi-1,P 16^INK4a expression.Results(1) The results of Western blot demonstrsted that the expression of Bmi-1 in cancerous tissues were significantly higher than that in paracancerous tissues and the expression of P16n^INK4a in cancerous tissues were significantly lower than that in paracancerous tissues.(2) The resuts of immunohistochemical study also showed that the expression of Bmi-1 and P16^INK4a protein were 85.39%and 44.62%in cancerous tissues respectively.①NSCLC with moderate or strong Bmi-1 expression were more likely to have low level of the P16^INK4a protein(P=0.0001).From our study we found that the expression of Bmi-1 was significantly higher in stageⅢ(P=0.02) tumors compared to stagesⅠandⅡtumors:②The expressions of Bmi-1 protein were highly correlated with lymph node metastasis(P=0.0008),Histology(P=0.01),TNM stage(P=0.02) and N stage (P=0.0073);The expressions of P 16^INK4a protein were highly correlated with lymph node metastasis(P=0.03),TNM stage(P=0.01),N stage(P=0.0001),but both are not with sex,age(P＞0.05):③The level of Bmi-1 protein expression was negatively correlated with P16^INK4a expression(r=-0.6938,P=0.0001). Conclusions Bmi-1 protein overexpression and the underexpression of P 16^INK4a was closely related to clinicopathological features and prognosis in NSCLC,and could be used as a marker oftumour burden of NSCLC.