Co-expression of Bmi1 and EZH2 as an independent poor prognostic factor in esophageal squamous cell carcinoma.

Bmi1 polycomb ring finger oncogene (Bmi1) and the enhancer of zeste homolog 2 (EZH2) are members of polycomb repressive complex (PRC) 1 and PRC2, respectively. PRC1 represses tumor suppressor genes such as p16INK4a and p14ARF in a PRC2-dependent manner. There have been few studies on Bmi1 or EZH2 expression in esophageal squamous cell carcinoma (ESCC). We investigated Bmi1 and EZH2 expression in 164 cases of ESCCs using immunohistochemistry, and evaluated the correlation with clinicopathologic features and their prognostic significance. Bmi1 and EZH2 were more highly expressed in tumor than in adjacent normal tissue (p<0.001). High expression of Bmi1 or EZH2 alone was not correlated with any clinicopathologic parameter and did not influence the prognosis. However, the group with high expression of both Bmi1 and EZH2 showed the poorest prognosis in overall survival (p=0.027) and disease-free survival (p=0.007). Also, it was an independent prognostic factor in overall survival (p=0.047). High expression of both Bmi1 and EZH2, not each alone, is an independent poor prognostic factor in ESCCs, supporting the repression of tumor suppressor gene by Bmi1 in an EZH2-dependent manner. This result suggests that both Bmi1 and EZH2, not each alone, could be potent candidates of new target therapy in ESCCs.

Ha SY ，Kim SH 《-》

Aberrant expression of EZH2 is associated with a poor outcome and P53 alteration in squamous cell carcinoma of the esophagus.

Yamada A ，Fujii S ，Daiko H ，Nishimura M ，Chiba T ，Ochiai A ... -  《-》

Aberrant expression of EZH2 is associated with pathological findings and P53 alteration.

Shiogama S ，Yoshiba S ，Soga D ，Motohashi H ，Shintani S ... -  《-》

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.

Kikuchi J ，Kinoshita I ，Shimizu Y ，Kikuchi E ，Konishi J ，Oizumi S ，Kaga K ，Matsuno Y ，Nishimura M ，Dosaka-Akita H ... -  《CANCER》

Combined aberrant expression of Bmi1 and EZH2 is predictive of poor prognosis in glioma patients.

Bmi1 and EZH2 are involved in tumorigenesis of gliomas. However, clinicopathologic significance of their expression in gliomas is unknown; especially, the prognostic value of combined expression of Bmi1 and EZH2 has not been explored. Bmi1 and EZH2 expression in human gliomas and nonneoplastic brain tissues was measured by immunohistochemistry. Both Bmi1 and EZH2 expressions in glioma tissues were significantly higher than those in corresponding nonneoplastic brain tissues (both P<0.001). Additionally, the upregulations of Bmi1 and EZH2 proteins were both significantly associated with advanced WHO grades (both P<0.001) and low KPS (P=0.008 and 0.01, respectively). Moreover, the overall survival of patients with high Bmi1 protein expression (P=0.006) or high EZH2 protein expression (P=0.01) was obviously lower than those with low expressions. More interestingly, glioma patients with combined overexpression of Bmi1 and EZH2 proteins had the shortest overall survival (P<0.001). Furthermore, multivariate analysis showed that Bmi1n expression (P=0.02), EZH2 expression (P=0.03), and combined expression of Bmi1 and EZH2 (P=0.008), were all independent prognostic factors for overall survival in glioma patients. Our data suggest for the first time that the combination of Bmi1 and EZH2 overexpression may be a highly sensitive marker for the prognosis in glioma patients.

Wu Z ，Wang Q ，Wang L ，Li G ，Liu H ，Fan F ，Li Z ，Li Y ，Tu Y ... -  《-》