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- Morris, John A, et al.
(författare)
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An atlas of genetic influences on osteoporosis in humans and mice.
- 2019
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Ingår i: Nature genetics. - : Springer Science and Business Media LLC. - 1546-1718 .- 1061-4036. ; 51, s. 258-266
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Tidskriftsartikel (refereegranskat)abstract
- Osteoporosis is a common aging-related disease diagnosed primarily using bone mineral density (BMD). We assessed genetic determinants of BMD as estimated by heel quantitative ultrasound in 426,824 individuals, identifying 518 genome-wide significant loci (301 novel), explaining 20% of its variance. We identified 13 bone fracture loci, all associated with estimated BMD (eBMD), in ~1.2 million individuals. We then identified target genes enriched for genes known to influence bone density and strength (maximum odds ratio (OR)=58, P=1 × 10-75) from cell-specific features, including chromatin conformation and accessible chromatin sites. We next performed rapid-throughput skeletal phenotyping of 126 knockout mice with disruptions in predicted target genes and found an increased abnormal skeletal phenotype frequency compared to 526 unselected lines (P<0.0001). In-depth analysis of one gene, DAAM2, showed a disproportionate decrease in bone strength relative to mineralization. This genetic atlas provides evidence linking associated SNPs to causal genes, offers new insight into osteoporosis pathophysiology, and highlights opportunities for drug development.
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2. |
- Harrison, Hannah, et al.
(författare)
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Contrasting hypoxic effects on breast cancer stem cell hierarchy is dependent on ERα status.
- 2013
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Ingår i: Cancer research. - 1538-7445. ; 73:4, s. 1420-33
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Tidskriftsartikel (refereegranskat)abstract
- Tumor hypoxia is often linked to decreased survival in breast cancer patients and current therapeutic strategies aim to target the hypoxic response. One way in which this is done is by blocking hypoxia induced angiogenesis. Anti-angiogenic therapies show some therapeutic potential with increased disease free survival but these initial promising results are short lived and followed by tumor progression. We hypothesized that this may be due to altered cancer stem cell (CSC) activity resulting from increased tumor hypoxia. We studied the effects of hypoxia on CSC activity, using in vitro mammosphere and holoclone assays as well as in vivo limiting dilution experiments, in 13 patient-derived samples and 4 cell lines. There was a HIF1-alpha-dependent CSC increase in ER-alpha-positive cancers following hypoxic exposure which was blocked by inhibition of estrogen and Notch signaling. A contrasting decrease in CSC was seen in ER-alpha-negative cancers. We next developed a xenograft model of cell lines and patient-derived samples to assess the hypoxic-CSC response. Varying sizes of xenografts were collected and analyzed for HIF1-alpha expression and CSC. The same ER-alpha-dependent contrasting hypoxic-CSC response was seen validating the initial observation. These data suggest that ER-alpha-positive and negative breast cancer sub-types respond differently to hypoxia and, as a consequence, anti-angiogenic therapies will not be suitable for both subgroups.
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