This Article Full Text Full Text (PDF) Supplementary Data All Versions of this Article: 1535-7163.MCT-07-0573v1 7/1/1    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Blower, P. E. Articles by Sadee, W. Search for Related Content PubMed PubMed Citation Articles by Blower, P. E. Articles by Sadee, W.

Spotlight on Molecular Profiling

MicroRNAs modulate the chemosensitivity of tumor cells

¹ Program of Pharmacogenomics, Department of Pharmacology and the Comprehensive Cancer Center, College of Medicine, ² Department of Statistics, ³ Mathematical Biosciences Institute, ⁴ College of Pharmacy, and ⁵ Department of Molecular Virology, Immunology and Medical Genetics, Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio; and ⁶ Genomics and Bioinformatics Group, Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland

Requests for reprints: Paul E. Blower, Program of Pharmacogenomics, Department of Pharmacology, Ohio State University, 333 West Tenth Street, Columbus, OH 43210. Phone: 615-688-5565. E-mail: blower.7{at}osu.edu

Abstract

MicroRNAs are strongly implicated in such processes as development, carcinogenesis, cell survival, and apoptosis. It is likely, therefore, that they can also modulate sensitivity and resistance to anticancer drugs in substantial ways. To test this hypothesis, we studied the pharmacologic roles of three microRNAs previously implicated in cancer biology (let-7i, mir-16, and mir-21) and also used in silico methods to test pharmacologic microRNA effects more broadly. In the experimental system, we increased the expression of individual microRNAs by transfecting their precursors (which are active) or suppressed the expression by transfection of antisense oligomers. In three NCI-60 human cancer cell lines, a panel of 60 lines used for anticancer drug discovery, we assessed the growth-inhibitory potencies of 14 structurally diverse compounds with known anticancer activities. Changing the cellular levels of let-7i, mir-16, and mir-21 affected the potencies of a number of the anticancer agents by up to 4-fold. The effect was most prominent with mir-21, with 10 of 28 cell-compound pairs showing significant shifts in growth-inhibitory activity. Varying mir-21 levels changed potencies in opposite directions depending on compound class; indicating that different mechanisms determine toxic and protective effects. In silico comparison of drug potencies with microRNA expression profiles across the entire NCI-60 panel revealed that 30 microRNAs, including mir-21, show highly significant correlations with numerous anticancer agents. Ten of those microRNAs have already been implicated in cancer biology. Our results support a substantial role for microRNAs in anticancer drug response, suggesting novel potential approaches to the improvement of chemotherapy. [Mol Cancer Ther 2008;7(1):1–9]

Grant support: National Institute of General Medical Sciences (GM61390), the National Science Foundation (under Agreement no. 0112050), and the Intramural Research Program of the NIH, National Cancer Institute, Center for Cancer Research.

The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

⁷ http://discover.nci.nih.gov

⁸ http://www.ambion.com

⁹ http://www.dtp.nci.nih.gov

Received 8/18/07; revised 11/ 1/07; accepted 12/ 4/07.