MiR-20b, -21, and -130b inhibit PTEN expression resulting in B7-H1 over-expression in advanced colorectal cancer.

Abstract

Co-inhibitor B7-H1 expresses in various cancers and contributes to cancer immune evasion by inhibiting T cell activation and proliferation, yet the regulatory mechanisms for B7-H1 over-expression in cancers remain largely unknown. Here, the expression of B7-H1 and PTEN proteins were firstly detected by using immunohistochemistry method. B7-H1 immunoreactivities were found in 54.5% (55/101) of the colorectal cancer tissues with no expression in the normal tissues, and the PTEN protein immunoreactivities were observed in 51.5% (52/101) of the colorectal cancer tissues and 72.3% (73/101) of the normal tissues. Statistical analysis results indicated that the B7-H1 expression was negatively correlated to the PTEN expression in colorectal cancer (p=0.001). Then the expressions of microRNAs (miRNAs) in six pairs of colorectal cancer and normal tissues were determined by miRNA array, and 30 up-regulated miRNAs were found in the colorectal cancer tissues. Finally, the impact of these up-regulated miRNAs on PTEN expression was tested by using dual-luciferase reporter assay system, from which the results indicated that miR-20b, -21, and -130b were involved in suppression of PTEN expression. These findings suggest that miR-20b, -21, and -130b, up-regulated in colorectal cancer, through inhibiting the expression of PTEN, result in B7-H1 over-expression in colorectal cancer.

• Authors: Jianjie Zhu, Lanxin Chen, Lingting Zou, Panpan Yang, Ruirong Wu, Yong Mao, Huan Zhou, Rui Li, Kaicai Wang, Weipeng Wang, Dong Hua, Xueguang Zhang
• Journal: Human immunology (Hum Immunol) Vol. 75 Issue 4 Pg. 348-53 (Apr 2014) ISSN: 1879-1166 [Electronic] United States
• PMID: 24468585 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2014 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

Chemical References

• 3' Untranslated Regions
• B7-H1 Antigen
• MIRN130 microRNA, human
• MIRN20a microRNA, human
• MIRN21 microRNA, human
• MicroRNAs
• PTEN Phosphohydrolase

Topics

• 3' Untranslated Regions
• Adult
• Aged
• Animals
• B7-H1 Antigen (genetics, metabolism)
• Cell Line
• Colorectal Neoplasms (genetics, metabolism, pathology)
• Female
• Gene Expression
• Gene Expression Regulation, Neoplastic
• Humans
• Male
• MicroRNAs (genetics, metabolism)
• Middle Aged
• Neoplasm Metastasis
• Neoplasm Staging
• PTEN Phosphohydrolase (genetics, metabolism)
• RNA Interference