Project description:Tumor associated miRNAs in hereditary breast cancer. In this study we investigated the role of miRNAs in hereditary breast tumors comparing with normal breast tissue. Global miRNA expression profiling was performed on 22 hereditary breast tumors and 15 non-tumoral breast tissues. We identified 19 miRNAs differentially expressed, most of them down-regulated in tumors. An important proportion of deregulated miRNAs in hereditary tumors were previously identified commonly deregulated in sporadic breast tumors. Our results identify miRNAs associated to hereditary breast cancer, as well as miRNAs commonly miss-expressed in hereditary and sporadic tumors, suggesting common underlying mechanisms of tumor progression. In addition, we provide evidence that KRAS is a target of miR-30c, and that this miRNA suppresses breast cancer cell growth potentially through inhibition of KRAS signaling.
Project description:Tumor associated miRNAs in hereditary breast cancer. In this study we investigated the role of miRNAs in hereditary breast tumors comparing with normal breast tissue. Global miRNA expression profiling was performed on 22 hereditary breast tumors and 15 non-tumoral breast tissues. We identified 19 miRNAs differentially expressed, most of them down-regulated in tumors. An important proportion of deregulated miRNAs in hereditary tumors were previously identified commonly deregulated in sporadic breast tumors. Our results identify miRNAs associated to hereditary breast cancer, as well as miRNAs commonly miss-expressed in hereditary and sporadic tumors, suggesting common underlying mechanisms of tumor progression. In addition, we provide evidence that KRAS is a target of miR-30c, and that this miRNA suppresses breast cancer cell growth potentially through inhibition of KRAS signaling. Single color experiments in a pairwise comparison design.
Project description:The objective of the study was to characterize hereditary breast tumors based on their miRNA expression profiles. To this end, we performed global miRNA expression analysis of more than 800 human miRNA genes in a large series of 80 FFPE breast tissue samples. The series included 66 hereditary breast primary tumors from 13 BRCA1 mutation carriers, 10 BRCA2 mutation carriers and 43 non-BRCA12 tumors denominated hereafter as BRCAX tumors. In addition we have analyzed 10 sporadic breast carcinomas and 4 normal breast tissues obtained after breast reduction surgery from healthy donors with no family history of breast cancer. To avoid contamination with normal breast tissue, tumoral area on FFPE blocks was marked by a pathologist and macrodissected for subsequent total RNA extraction.
Project description:In this study, we characterize the fusion protein produced by the EPC1-PHF1 translocation in Low Grade Endometrial Stromal Sarcoma (LG-ESS) and Ossifying FibroMyxoid Tumors (OFMT). We express the fusion protein and necessary controls in K562 Cells. The fusion protein assembles a mega-complex harboring both NuA4/TIP60 and PRC2 subunits and enzymatic activities and leads to mislocalization of chromatin marks in the genome, linked to aberrant gene expression.
Project description:Breast tumors from BRCA1 germ line mutation carriers typically exhibit features of the basal-like molecular subtype. However, the specific genes recurrently mutated as a consequence of BRCA1 dysfunction have not been fully elucidated. In this study, we utilized gene expression profiling to molecularly subtype 577 breast tumors, including 73 breast tumors from BRCA1/2 mutation carriers. Focusing on the RB1 locus, we analyzed 33 BRCA1-mutated, 36 BRCA2-mutated and 48 non-BRCA1/2-mutated breast tumors using a custom-designed high-density oligomicroarray covering the RB1 gene. We found a strong association between the basal-like subtype and BRCA1-mutated breast tumors and the luminal B subtype and BRCA2-mutated breast tumors. RB1 was identified as a major target for genomic disruption in tumors arising in BRCA1 mutation carriers and in sporadic tumors with BRCA1 promoter-methylation, but rarely in other breast cancers. Homozygous deletions, intragenic breaks, or microdeletions were found in 33% of BRCA1-mutant tumors, 36% of BRCA1 promoter-methylated basal-like tumors, 13% of non-BRCA1 deficient basal-like tumors, and 3% of BRCA2-mutated tumors. In addition, RB1 was frequently inactivated by gross gene disruption in BRCA1-related hereditary breast cancer and BRCA1-methylated sporadic basal-like breast cancer, but rarely in BRCA2-hereditary breast cancer and non-BRCA1-deficient sporadic breast cancers. Together, our findings demonstrate the existence of genetic heterogeneity within the basal-like breast cancer subtype that is based upon BRCA1-status. Gene expression profiling of breast tumors. Dual color common reference gene expression study using 55K oligonucleotide microarrays.