Cancer Research Infection and Cancer: Biology, Therapeutics, and Prevention  Joint Metastasis Research Society-AACR Conference on Metastasis
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Cancer Research Clinical Cancer Research
Cancer Epidemiology Biomarkers & Prevention Molecular Cancer Therapeutics
Molecular Cancer Research Cancer Prevention Research
Cancer Prevention Journals Portal Cancer Reviews Online
Annual Meeting Education Book Meeting Abstracts Online

Cancer Research 68, 2773-2780, April 15, 2008. doi: 10.1158/0008-5472.CAN-07-6754
© 2008 American Association for Cancer Research

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Supplementary Data
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Google Scholar
Right arrow Articles by Medina, R.
Right arrow Articles by Stein, G. S.
PubMed
Right arrow PubMed Citation
Right arrow Articles by Medina, R.
Right arrow Articles by Stein, G. S.

Cell, Tumor, and Stem Cell Biology

MicroRNAs 221 and 222 Bypass Quiescence and Compromise Cell Survival

Ricardo Medina1, Sayyed K. Zaidi1, Chang-Gong Liu2, Janet L. Stein1, Andre J. vanWijnen1, Carlo M. Croce2 and Gary S. Stein1

1 Department of Cell Biology and Cancer Center, University of Massachusetts Medical School, Worcester, Massachusetts and 2 Department of Molecular Virology, Immunology and Medical Genetics and Comprehensive Cancer Center, Ohio State University, Columbus, Ohio

Requests for reprints: Gary S. Stein, Department of Cell Biology and Cancer Center, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655. Phone: 508-856-5625; Fax: 508-856-6800; E-mail: gary.stein{at}umassmed.edu.

Key Words: cell cycle • miRNA • miR-221 • miR-222 • p27/Kip1 • p57/Kip2 • T98G glioblastoma

MicroRNAs (miRNA) have tumor suppressive and oncogenic potential in human cancer, but whether and how miRNAs control cell cycle progression is not understood. To address this question, we carried out a comprehensive analysis of miRNA expression during serum stimulation of quiescent human cells. Time course analyses revealed that four miRNAs are up-regulated and >100 miRNAs are down-regulated, as cells progress beyond the G1-S phase transition. We analyzed the function of two up-regulated miRNAs (miR-221 and miR-222) that are both predicted to target the cell growth suppressive cyclin-dependent kinase inhibitors p27 and p57. Our results show that miR-221 and miR-222 both directly target the 3' untranslated regions of p27 and p57 mRNAs to reduce reporter gene expression, as well as diminish p27 and p57 protein levels. Functional studies show that miR-221 and miR-222 prevent quiescence when elevated during growth factor deprivation and induce precocious S-phase entry, thereby triggering cell death. Thus, the physiologic up-regulation of miR-221 and miR-222 is tightly linked to a cell cycle checkpoint that ensures cell survival by coordinating competency for initiation of S phase with growth factor signaling pathways that stimulate cell proliferation. [Cancer Res 2008;68(8):2773–80]







HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Cancer Research Clinical Cancer Research
Cancer Epidemiology Biomarkers & Prevention Molecular Cancer Therapeutics
Molecular Cancer Research Cancer Prevention Research
Cancer Prevention Journals Portal Cancer Reviews Online
Annual Meeting Education Book Meeting Abstracts Online
Copyright © 2008 by the American Association for Cancer Research.