Fax: (011) 81-11-706-5077
Distinctive expression of the polycomb group proteins Bmi1 polycomb ring finger oncogene and enhancer of zeste homolog 2 in nonsmall cell lung cancers and their clinical and clinicopathologic significance
Version of Record online: 30 MAR 2010
Copyright © 2010 American Cancer Society
Volume 116, Issue 12, pages 3015–3024, 15 June 2010
How to Cite
Kikuchi, J., Kinoshita, I., Shimizu, Y., Kikuchi, E., Konishi, J., Oizumi, S., Kaga, K., Matsuno, Y., Nishimura, M. and Dosaka-Akita, H. (2010), Distinctive expression of the polycomb group proteins Bmi1 polycomb ring finger oncogene and enhancer of zeste homolog 2 in nonsmall cell lung cancers and their clinical and clinicopathologic significance. Cancer, 116: 3015–3024. doi: 10.1002/cncr.25128
- Issue online: 11 JUN 2010
- Version of Record online: 30 MAR 2010
- Manuscript Revised: 23 OCT 2009
- Manuscript Accepted: 23 OCT 2009
- Manuscript Received: 8 SEP 2009
- polycomb group protein;
- nonsmall cell lung cancer;
The polycomb group genes Bmi1 polycomb ring finger oncogene (Bmi1) and enhancer of zeste homolog 2 (EZH2) function as transcriptional repressors involved in gene silencing and in the malignant transformation and biologic aggressiveness of several human carcinomas. In the current study, the authors evaluated Bmi1 and EZH2 protein expression in specimens of human nonsmall cell lung cancer (NSCLC).
The authors conducted an immunohistochemical assessment of 157 surgically resected NSCLCs to evaluate the correlation between Bmi1 and EZH2 expression and various features, including clinical, clinicopathologic, and biologic characteristics.
Normal bronchial epithelia revealed abundant expression of Bmi1 and sporadic expression of EZH2. Patients who had high EZH2 expression in tumor cells had a poorer prognosis than patients who had low EZH2 expression in tumor cells all pathologic stages of NSCLC (P = .001) and in pathologic stage I NSCLC (P = .006). Multivariate analysis revealed that high EZH2 expression was a independent, unfavorable prognostic factor in patients with pathologic stage I disease (P = .048). High EZH2 expression was correlated significantly with nonadenocarcinoma histology (P = .001), moderate and poor differentiation (P = .001), advanced pathologic tumor classification (P = .02), and high Ki-67 and cyclin E labeling indices (P < .001). Bmi1 expression, in contrast, was not a significant prognostic factor and was not correlated with any clinicopathologic factors other than early pathologic tumor classification.
Bmi1 and EZH2 had characteristic and distinctive expression in NSCLCs. High EZH2 expression was correlated with tumor aggressiveness and may provide a novel prognostic marker for NSCLCs. Cancer 2010. © 2010 American Cancer Society.