Project description:165 primary breast carcinomas were selected to study the gene expression profile in relation to the risk of developping local recurrence after breast conserving therapy; in addition 15 recurred tumors were profiled for comparison to their primary tumor.
Project description:97 triple negative tumors were selected from the fresh-frozen tissue bank of the Netherlands Cancer Institute and gene expression profiles were generated using 35K oligonucleotide microarrays. Human breast carcinomas were snap frozen in liquid nitrogen within one hour after surgery and stored in the fresh-frozen tissue bank of the Netherlands Cancer Institute. RNA from a pool of more than 100 unselected fresh frozen breast carcinomas were isolated and pooled to form the reference to which each individual breast carcinoma is hybridized.
Project description:Gene expression array analysis on a series of ten different histological special types of invasive breast carcinomas (tubular, micropapillary, mucinous A, mucinous B, endocrine, apocrine, metaplastic, medullary, adenoid cystic, invasive ductal carcinoma with osteoclastic giant cells) and invasive lobular carcinoma.<br><br>Note: this experiment was reloaded into ArrayExpress in August 2010 to include mappings between raw and processed data files. It now includes additional dye-swap combined normalized data files.
Project description:Heterogeneity of gene expression profiles in head and neck cancer Background: Results of gene expression profiling studies from different institutes often lack consistency. This could be due to the use of different microarray platforms and protocols, or to intra-tumoral heterogeneity in mRNA expression. The aim of our study was to quantify intra-tumoral heterogeneity in head and cancer. Methods: Forty-four fresh frozen biopsies were taken from 22 patients, two per tumor. RNA was extracted, tested for quality, amplified, labeled and hybridized to a 35k oligoarray. Results: Unsupervised clustering analyses using all genes, the most variable genes, or random gene sets showed that 80-90% of biopsy pairs clustered together. A within-pair-between-pair scatter ratio analysis showed that the similarity between matching pairs was significantly greater than that between random pairs (p < 0.00001). Conclusions: Two biopsies from the same tumor show far greater similarity in gene expression than biopsies from different tumors, supporting the use of one biopsy for expression profiling.