|
| This article is part of the supplement: Breast Cancer Research 2008 .Poster presentationNRG1 is frequently silenced by methylation in breast cancers and is a strong candidate for the 8p tumour suppressor gene1 Department of Pathology, University of Cambridge, Hutchison/MRC Research Centre, Cambridge, UK 2 CR-UK Cambridge Research Institute, Cambridge, UK 3 Department of Pathology, University of Nottingham, UK 4 Ludwig Institute for Cancer Research Breast Cancer Laboratory, University College, London, UK from Breast Cancer Research 2008 Breast Cancer Research 2008, 10(Suppl 2):P11doi:10.1186/bcr1895 The electronic version of this abstract is the complete one and can be found online at: http://breast-cancer-research.com/content/10/S2/P11
© 2008 BioMed Central Ltd BackgroundIt has long been suspected that there is an important breast cancer tumour suppressor gene on the short arm of chromosome 8, 8p, and our array CGH data suggest that it may be close to NRG1 [1]. NRG1 encodes growth factors that bind to tyrosine kinases ErbB3 and ErbB4, and can both stimulate cell proliferation and apoptosis. NRG1 is also quite frequently broken by chromosome translocations [2]. Methods and resultsBy quantitiative PCR, NRG1 expression was repressed or abolished in many breast cancer cell lines and tumours as compared with normal breast. Methylation analysis by sequencing or pyrosequencing bisulphite-treated DNA showed striking DNA methylation at a CpG island in NRG1, which is correlated with an absence of NRG1 transcripts. Treatment of cancer cell lines with 5-aza-2-deoxycytidine reactivated the expression of NRG1 by 7 to 100 times. NRG1 was also methylated in tumour tissue samples while it was not in uncultured normal breast epithelium. Knocking down NRG1 expression by siRNA led to an increase in net cell proliferation. ConclusionNRG1 could be the 8p tumour suppressor gene. It is located in the right place. It is silenced by methylation or other mechanisms in many breast cancer cell lines and tumours. Functionally, NRG1 expression is antiproliferative – shown both by our siRNA experiments and older work that showed expression to be proapoptotic to breast cancer cell line MCF7 [3]. AcknowledgementsSupported by Breast Cancer Campaign and also Cancer Research UK and the Ludwig Institute for Cancer Research. References
Have something to say? Post a comment on this article! |



on Google Scholar





