Poster #RP227
Selection of splicing variant candidates in breast cancer through microarray platform
Maria Cristina Rodrigues Rangel*, Natanja Sara Kirschbaum-Slager*, Luiz Paulo Camargo**, Sandro José de Souza*, Helena Paula Brentani**, Dirce Maria Carraro*
*Ludwig Institute for Cancer Research; **Hospital do Câncer AC Camargo
Current analyses have shown that alternative mRNA splicing (AS) appears in at least 70% of human genes, contributing to the wide diversity of transcripts. The correlation of specific variants with clinical information of cancer patients increase the possibility to identify tumor markers. With this purpose, 270 tumor-associated exons were selected by a computational analysis and were immobilized on a nylon membrane. Samples were manually microdissected and total RNA were amplified in 2 rounds using T7 based methodology. Five micrograms of amplified RNA were labeled with 60 uCi of ?32P-dCTP. Twenty-seven tumoral and 5 non-neoplastic breast tissues were hybridized in duplicate. T student test was applied to determine differentially expressed exons (p<0.05) between tumors and non-neoplastic cell lines and samples. Fourteen exons overexpressed in breast cancer were selected with differential expression fold ranging from 3.0 to 5.9, displaying significant representativity among the 75 exons previously selected by computational analysis as breast cancer-associated. From 7 exons with reliable information at SAGE bank, none of the respective genes showed to be over-expressed, supporting the hypothesis that the over-expression was of its variants only. Some of the genes, like BAP1, LIP8, MBTPS1, PRKD2, TRIM 37 and PPP1R8 might be related with cancer.