MCM2 and Ki-67 expression in human lung adenocarcinoma: prognostic implications.

OBJECTIVE

The expressions of minichromosome maintenance protein 2 (MCM2), Ki-67, and p53 were examined to analyze their pathobiological significance in human lung adenocarcinomas.

METHODS

We performed Western blot analysis in six human lung adenocarcinoma cell lines and immunohistochemistry in 145 surgically removed adenocarcinomas to examine the MCM2 expression. Labeling indices (LIs; %) of MCM2, Ki-67, and p53 in the tumor cells were compared with clinicopathological profiles and overall survival rates.

RESULTS

MCM2 protein was detected in all cell lines examined, with specific bands. MCM2 LIs were significantly correlated with sex, histological type, differentiation, pathological stage, and LIs of Ki-67 and p53 (p < 0.05). Significantly higher LIs of MCM2 and Ki-67 were noted in the 122 non-pure bronchioloalveolar carcinomas than in the 23 pure bronchioloalveolar carcinomas (p < 0.01), and the prognosis was poorer in the former than in the latter (p < 0.01). Sex, pathological stage, and high LIs of MCM2 and/or Ki-67 were independent prognostic factors (p < 0.05).

CONCLUSION

High LIs of MCM2 and/or Ki-67 suggest a poor prognosis in patients with lung adenocarcinoma (non-pure bronchioloalveolar carcinoma).