This SuperSeries is composed of the SubSeries listed below.
Novel subtype-specific genes identify distinct subpopulations of callosal projection neurons.
Specimen part
View Samples3 subtypes of cortical projection neurons were purified by fluorescence-activated cell sorting (FACS) at 4 different stages of development from mouse cortex. A detailed description of the data set is described in Arlotta, P et al (2005) and Molyneaux, BJ et al (2009). The hybridization cocktails used here were originally applied to the Affymetrix mouse 430A arrays and submitted as GEO accession number GSE2039. The same hybridization cocktails were then applied to the Affymetrix mouse 430 2.0 arrays, and those data are contained in this series.
Novel subtype-specific genes identify distinct subpopulations of callosal projection neurons.
Specimen part
View SamplesBRCA1, a well-known breast and ovarian cancer susceptibility gene with multiple interacting partners, is predicted to have diverse biological functions. However, to date its only well-established role is in the repair of damaged DNA and cell cycle regulation. In this regard, the etiopathological study of low penetrant variants of BRCA1 provides an opportunity to uncover its other physiologically important functions. Using this rationale, we studied the R1699Q variant of BRCA1, a potentially moderate risk variant, and found that it does not impair DNA damage repair but abrogates the repression of miR-155, a bona fide oncomir. We further show that in the absence of functional BRCA1, miR-155 is up-regulated in BRCA1-deficient mouse mammary epithelial cells, human and mouse BRCA1-deficienct breast tumor cell lines as well as tumors. Mechanistically, we found that BRCA1 represses miR-155 expression via its association with HDAC2, which deacetylates H2A and H3 on the miR-155 promoter. Finally, we show that over-expression of miR-155 accelerates whereas the knockdown of miR-155 attenuates the growth of tumor cell lines in vivo. Taken together, our findings demonstrate a new mode of tumor suppression by BRCA1 and reveal miR-155 as a potential therapeutic target for BRCA1-deficient tumors.
Tumor suppressor BRCA1 epigenetically controls oncogenic microRNA-155.
Specimen part
View SamplesWe examined the functional significance of the R1699Q variant of human BRCA1 gene using a mouse ES cell-based assay.
Tumor suppressor BRCA1 epigenetically controls oncogenic microRNA-155.
Specimen part
View Samples