Cellosaurus publication CLPUB00734

Publication number	CLPUB00734
Authors	Silva A.P.M., Carraro D.M., Pires L.C., Jongeneel V.C., De Souza S.J., Camargo A.A.
Title	Characterization of novel c-erbB2 regulated genes using massively parallel signature sequencing (MPSS).
Citation	Cancer Res. 66 Suppl. 8:19-20(2006)
Web pages	https://aacrjournals.org/cancerres/article/66/8_Supplement/19/532558
Abstract	Overexpression of the proto-oncogene c-erbB2 is observed in 30% of breast tumors and is considered an adverse prognostic factor for breast cancer. However, the molecular mechanisms associated with c-erbB2 overexpression are not yet understood. In this work, transcriptional changes associated with c-erbB2 overexpression were investigated using Massively Parallel Signature Sequencing (MPSS). MPSS is a powerful technique for genome-wide gene expression analysis, which relies on the production and quantification of short tags proximal to the 3' end of transcripts. Over 24 million MPSS tags, representing aproximately 17,000 different genes were generated for a immortalized mammary luminal epithelial cell line (HB4a) and for a variant cell line (C5.2) transfected with c-erbB2. After establishing reliable correlations between tags and known human transcripts, 9% of the tags could not be associated with a known transcripts and were designated orphan tags. Among the orphan tags there were many that showed differential expression between HB4a and C5.2 cell lines and probably represent novel genes regulated by c-erbB2. In order to further characterize these novel genes, we have extended 83 tags orphan tags towards the 3' end of the corresponding mRNA molecule using a methodology named GLGI (Generation of Longer cDNA fragments for Gene Identification). Forty one 3' cDNA fragments were obtained and similarity analysis of these fragments using BLAST allowed the identification of 10 transcripts putativelly regulated by c-erB2. Differential expression in the C5.2 cell line of 3 out of the 10 transcripts putativelly regulated by c-erbB2 was confirmed by real-time PCR. We are currently investigating the effects of Herceptin treatment on gene expression patterns in HER2- amplified and nonamplified breast cancer cell lines in order to elucidate the molecular consequences of blocking the HER pathway.
Cell lines	CVCL_J984; C5.2 CVCL_J982; HB4a