MicroRNA-34b and MicroRNA-34c Are Targets of p53 and Cooperate in Control of Cell Proliferation and Adhesion-Independent Growth.

@article{citeulike:1639281, abstract = {MicroRNAs (miRNA) are a recently discovered class of noncoding RNAs that negatively regulate gene expression. Recent evidence indicates that miRNAs may play an important role in cancer. However, the mechanism of their deregulation in neoplastic transformation has only begun to be understood. To elucidate the role of tumor suppressor p53 in regulation of miRNAs, we have analyzed changes in miRNA microarray expression profile immediately after conditional inactivation of p53 in primary mouse ovarian surface epithelium cells. Among the most significantly affected miRNAs were miR-34b and miR-34c, which were down-regulated 12-fold according to quantitative reverse transcription-PCR analysis. Computational promoter analysis of the mir-34b/mir-34c locus identified the presence of evolutionarily conserved p53 binding sites approximately 3 kb upstream of the miRNA coding sequence. Consistent with evolutionary conservation, mir-34b/mir-34c were also down-regulated in p53-null human ovarian carcinoma cells. Furthermore, as expected from p53 binding to the mir-34b/c promoter, doxorubicin treatment of wild-type, but not p53-deficient, cells resulted in an increase of mir-34b/mir-34c expression. Importantly, miR-34b and miR-34c cooperate in suppressing proliferation and soft-agar colony formation of neoplastic epithelial ovarian cells, in agreement with the partially overlapping spectrum of their predicted targets. Taken together, these results show the existence of a novel mechanism by which p53 suppresses such critical components of neoplastic growth as cell proliferation and adhesion-independent colony formation. [Cancer Res 2007;67(18):8433-8].}, address = {Department of Biomedical Sciences and Microarray Core Facility, Cornell University, Ithaca, New York and Department of Medical Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania.}, author = {Corney, David C C. and Flesken-Nikitin, Andrea and Godwin, Andrew K K. and Wang, Wei and Nikitin, Alexander Yu Y. }, citeulike-article-id = {1639281}, doi = {10.1158/0008-5472.CAN-07-1585}, issn = {0008-5472}, journal = {Cancer Res}, keywords = {cancer, micro-rna}, month = {September}, posted-at = {2007-09-10 16:17:59}, priority = {2}, title = {MicroRNA-34b and MicroRNA-34c Are Targets of p53 and Cooperate in Control of Cell Proliferation and Adhesion-Independent Growth.}, url = {http://dx.doi.org/10.1158/0008-5472.CAN-07-1585}, year = {2007} }

TY - JOUR ID - citeulike:1639281 L3 - citeulike-article-id:1639281 TI - MicroRNA-34b and MicroRNA-34c Are Targets of p53 and Cooperate in Control of Cell Proliferation and Adhesion-Independent Growth. JF - Cancer Res AD - Department of Biomedical Sciences and Microarray Core Facility, Cornell University, Ithaca, New York and Department of Medical Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania. SN - 0008-5472 N2 - MicroRNAs (miRNA) are a recently discovered class of noncoding RNAs that negatively regulate gene expression. Recent evidence indicates that miRNAs may play an important role in cancer. However, the mechanism of their deregulation in neoplastic transformation has only begun to be understood. To elucidate the role of tumor suppressor p53 in regulation of miRNAs, we have analyzed changes in miRNA microarray expression profile immediately after conditional inactivation of p53 in primary mouse ovarian surface epithelium cells. Among the most significantly affected miRNAs were miR-34b and miR-34c, which were down-regulated 12-fold according to quantitative reverse transcription-PCR analysis. Computational promoter analysis of the mir-34b/mir-34c locus identified the presence of evolutionarily conserved p53 binding sites approximately 3 kb upstream of the miRNA coding sequence. Consistent with evolutionary conservation, mir-34b/mir-34c were also down-regulated in p53-null human ovarian carcinoma cells. Furthermore, as expected from p53 binding to the mir-34b/c promoter, doxorubicin treatment of wild-type, but not p53-deficient, cells resulted in an increase of mir-34b/mir-34c expression. Importantly, miR-34b and miR-34c cooperate in suppressing proliferation and soft-agar colony formation of neoplastic epithelial ovarian cells, in agreement with the partially overlapping spectrum of their predicted targets. Taken together, these results show the existence of a novel mechanism by which p53 suppresses such critical components of neoplastic growth as cell proliferation and adhesion-independent colony formation. [Cancer Res 2007;67(18):8433-8]. KW - cancer KW - micro-rna AU - Corney, David C AU - Flesken-Nikitin, Andrea AU - Godwin, Andrew K AU - Wang, Wei AU - Nikitin, Alexander Yu PY - 2007/09/06/ UR - http://dx.doi.org/10.1158/0008-5472.CAN-07-1585 ER -