Natrajan, R., Mackay, A., Wilkerson, P. M., Lambros, M. B., Wetterskog, D., Arnedos, M., Shiu, K. K., Geyer, F. C., Langerod, A., Kreike, B., Reyal, F., Horlings, H. M., van de Vijver, M. J., Palacios, J., Weigelt, B., Reis, J. S. (2012) Functional characterization of the 19q12 amplicon in grade III breast cancers. BREAST CANCER RESEARCH, 14 (2). ISSN 1465-5411

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Abstract

Introduction: The 19q12 locus is amplified in a subgroup of oestrogen receptor (ER)-negative grade III breast cancers. This amplicon comprises nine genes, including cyclin E1 (CCNE1), which has been proposed as its 'driver'. The aim of this study was to identify the genes within the 19q12 amplicon whose expression is required for the survival of cancer cells harbouring their amplification. Methods: We investigated the presence of 19q12 amplification in a series of 313 frozen primary breast cancers and 56 breast cancer cell lines using microarray comparative genomic hybridisation (aCGH). The nine genes mapping to the smallest region of amplification on 19q12 were silenced using RNA interference in phenotypically matched breast cancer cell lines with (MDA-MB-157 and HCC1569) and without (Hs578T, MCF7, MDA-MB-231, ZR75.1, JIMT1 and BT474) amplification of this locus. Genes whose silencing was selectively lethal in amplified cells were taken forward for further validation. The effects of cyclin-dependent kinase 2 (CDK2) silencing and chemical inhibition were tested in cancer cells with and without CCNE1 amplification. Results: 19q12 amplification was identified in 7.8% of ER-negative grade III breast cancer. Of the nine genes mapping to this amplicon, UQCRFS1, POP4, PLEKHF1, C19ORF12, CCNE1 and C19ORF2 were significantly overexpressed when amplified in primary breast cancers and/or breast cancer cell lines. Silencing of POP4, PLEKHF1, CCNE1 and TSZH3 selectively reduced cell viability in cancer cells harbouring their amplification. Cancer cells with CCNE1 amplification were shown to be dependent on CDK2 expression and kinase activity for their survival. Conclusions: The 19q12 amplicon may harbour more than a single 'driver', given that expression of POP4, PLEKHF1, CCNE1 and TSZH3 is required for the survival of cancer cells displaying their amplification. The observation that cancer cells harbouring CCNE1 gene amplification are sensitive to CDK2 inhibitors provides a rationale for the testing of these chemical inhibitors in a subgroup of patients with ER-negative grade III breast cancers.

Item Type:	Article
Authors (ICR Faculty only):	Reis-Filho, Jorge and Natrajan, Rachael
All Authors:	Natrajan, R., Mackay, A., Wilkerson, P. M., Lambros, M. B., Wetterskog, D., Arnedos, M., Shiu, K. K., Geyer, F. C., Langerod, A., Kreike, B., Reyal, F., Horlings, H. M., van de Vijver, M. J., Palacios, J., Weigelt, B., Reis, J. S.
Additional Information:	ISI Document Delivery No.: 952DZ Times Cited: 0 Cited Reference Count: 64 Natrajan, Rachael Mackay, Alan Wilkerson, Paul M. Lambros, Maryou B. Wetterskog, Daniel Arnedos, Monica Shiu, Kai-Keen Geyer, Felipe C. Langerod, Anita Kreike, Bas Reyal, Fabien Horlings, Hugo M. van de Vijver, Marc J. Palacios, Jose Weigelt, Britta Reis-Filho, Jorge S. Breakthrough Breast Cancer; Cancer Research UK; NHS We thank Radost Vatcheva and Frederik Wallberg for technical assistance. This work was supported by Breakthrough Breast Cancer. BW is funded by a Cancer Research UK postdoctoral fellowship. Jorge S Reis-Filho is a recipient of the 2010 CRUK Future Leaders Prize. We acknowledge NHS funding to the NIHR Biomedical Research Centre. Biomed central ltd London
Uncontrolled Keywords:	comparative genomic hybridization potential therapeutic target in-situ hybridization dna amplifications gene amplification 8p11-12 amplicon cell-lines resolution carcinomas microarray
Research teams:	Closed research groups > Molecular Pathology ICR divisions > Breast Cancer Research > Functional Genomics
Depositing User:	Alexander Smithson
Date Deposited:	02 Jul 2012 15:41
Last Modified:	25 Feb 2014 13:14
URI:	http://publications.icr.ac.uk/id/eprint/11765

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