Observational Study
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World J Gastroenterol. May 14, 2014; 20(18): 5533-5539
Published online May 14, 2014. doi: 10.3748/wjg.v20.i18.5533
Expression of Bmi-1 and PAI-1 in esophageal squamous cell carcinoma
Yan Zhang, Ya-Lou Zhang, Hong-Ming Chen, Hong-Wei Pu, Wen-Jing Ma, Xiao-Mei Li, Hong Ma, Xiao Chen
Yan Zhang, Ya-Lou Zhang, Hong-Ming Chen, Wen-Jing Ma, College of Basic Medical Sciences, Xinjiang Medical University, Urumqi 830011, Xinjiang Uygur Autonomous Region, China
Hong-Wei Pu, Clinical Research Institute, Xinjiang Medical University, Urumqi 830054, Xinjiang Uygur Autonomous Region, China
Xiao-Mei Li, Vocational and Technical College, Xinjiang Medical University, Urumqi 830011, Xinjiang Uygur Autonomous Region, China
Hong Ma, Xiao Chen, Department of Pathology, Xinjiang Medical University, Urumqi 830011, Xinjiang Uygur Autonomous Region, China
Author contributions: Chen X, Zhang Y and Zhang YL were the principal investigators; Zhang Y and Zhang YL contributed to the conceptual design, drafted the manuscript and revised it critically for important intellectual content; Pu HW, Ma WJ, Ma H and Zhang Y performed the statistical analysis of data and wrote the initial draft of the paper; Chen X, Chen HM and Li XM revised the paper; all authors actively enrolled patients into the trial and approved the final version of the manuscript.
Supported by Natural Science Foundation of Xinjiang Uygur Autonomous Region, No. 2012211A035; Graduate Research and Innovation Project of Xnjiang Uygur Autonomous Region, No. XJGRI2013076; Research and Innovation Project of Xinjiang Medical University, No. XJC201314.
Correspondence to: Xiao Chen, PhD, Professor, Department of Pathology, Xinjiang Medical University, No. 339 Xin Yi Road, Urumqi 830011, Xinjiang Uygur Autonomous Region, China. xjchenxiao@sina.com
Telephone: +86-991-4363877 Fax: +86-991-3857166
Received: November 6, 2013
Revised: February 8, 2014
Accepted: March 19, 2014
Published online: May 14, 2014
Processing time: 186 Days and 18.9 Hours
Abstract

AIM: To determine the correlation between invasiveness, migration and prognosis in esophageal squamous cell carcinoma (ESCC) and expression of the B-cell-specific Moloney leukemia virus insert site 1 (Bmi-1) and plasminogen activator inhibitor-1 (PAI-1).

METHODS: Eighty previously untreated patients who underwent surgical excision of ESCC were included. The expression of Bmi-1 and PAI-1 was examined immunohistochemically in formalin-fixed paraffin-embedded primary tissue specimens. The relationships between the expression of Bmi-1 and PAI-1, the clinicopathologic features of ESCC, and the survival rate of ESCC patients were also discussed. The correlation between Bmi-1 and PAI-1 protein expression in ESCC was analyzed. The relationship between Bmi-1 and PAI-1 expression and ESCC prognosis was evaluated using a Cox regression model and Kaplan-Meier survival curve analysis.

RESULTS: The rates of positive Bmi-1 and PAI-1 expression in ESCC were higher than those in normal esophageal tissue (P < 0.05). The expression of Bmi-1 and PAI-1 was correlated with depth of invasion and lymph node metastasis (P < 0.05), but not with patient age, tumor size or nationality (P > 0.05). The expression of Bmi-1 was positively correlated with that of PAI-1 (P < 0.05). The 10-year overall survival rate for all patients was 20% (16/80). Univariate Kaplan-Meier survival analysis showed that patients with high expression of esophageal PAI-1 and Bmi-1 had lower survival, however, the difference was not statistically significant. Cox multivariate analysis showed that PAI-1 and Bmi-1 were not independent factors for survival rate, while the depth of tumor invasion and metastasis were independent factors affecting patient survival.

CONCLUSION: The expression of Bmi-1 and PAI-1 plays a role in ESCC progression, and may be used as a prognostic marker in ESCC.

Keywords: Esophageal squamous cell carcinoma; B-cell-specific moloney leukemia virus insert site 1; Plasminogen activator inhibitor-1; Metastasis; Prognosis

Core tip: In this study, B-cell-specific Moloney leukemia virus insert site 1 (Bmi-1) and plasminogen activator inhibitor-1 (PAI-1) expression, their correlation with clinicopathological features, and their prognostic significance in esophageal squamous cell carcinoma (ESCC) were examined. The results showed that the Bmi-1 protein promoted malignant transformation, increased invasion and metastasis of cells. PAI-1 was not an independent prognostic factor. Although these new markers are important, the molecular mechanism of ESCC metastasis is far from being fully understood and represents a new prerequisite for developing better treatment strategies.