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- Almered Olsson, Gunilla, 1951, et al.
(författare)
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Variation in Life History Traits of Gentiana nivalis (Gentianaceae) in Alpine and Sub-alpine Habitats in the Norwegian Mountains – Implications for Biodiversity in relation to Environmental Change
- 2015
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Ingår i: Annales Botanici Fennici. - : Finnish Zoological and Botanical Publishing Board. - 0003-3847 .- 1797-2442. ; 52:3-4, s. 149-159
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Tidskriftsartikel (refereegranskat)abstract
- The alpine gentian, Gentiana nivalis, is an obligate annual. Because of its complete population turnover every year, it is likely to be more responsive to environmental shifts than are perennials, and also likely to undergo more rapid genetic change in response to selection pressure. The detected morphological differentiation between habitats was related to different proportions of spring- and autumn-germinating individuals with a larger proportion of winter annuals in the subalpine habitats. The spring-germinating annuals that have shorter time for development and have a shorter stature can still develop at the alpine sites where competition is weaker. The subalpine habitats are all semi-natural, shaped by livestock grazing and human activities related to summer farming. Declining human impact is leading to successional changes in the mountain landscape. The future of G. nivalis in the light of current trends in landscape development and climate change is discussed.
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| 2. |
- Francis, Princy, et al.
(författare)
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Diagnostic and prognostic gene expression signatures in 177 soft tissue sarcomas: hypoxia-induced transcription profile signifies metastatic potential.
- 2007
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Ingår i: BMC Genomics. - : Springer Science and Business Media LLC. - 1471-2164. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Background Soft tissue sarcoma (STS) diagnosis is challenging because of a multitude of histopathological subtypes, different genetic characteristics, and frequent intratumoral pleomorphism. One-third of STS metastasize and current risk-stratification is suboptimal, therefore, novel diagnostic and prognostic markers would be clinically valuable. We assessed the diagnostic and prognostic value of array-based gene expression profiles using 27 k cDNA microarrays in 177, mainly high-grade, STS of 13 histopathological subtypes. Results Unsupervised analysis resulted in two major clusters – one mainly containing STS characterized by type-specific genetic alterations and the other with a predominance of genetically complex and pleomorphic STS. Synovial sarcomas, myxoid/round-cell liposarcomas, and gastrointestinal stromal tumors clustered tightly within the former cluster and discriminatory signatures for these were characterized by developmental genes from the EGFR, FGFR, Wnt, Notch, Hedgehog, RAR and KIT signaling pathways. The more pleomorphic STS subtypes, e.g. leiomyosarcoma, malignant fibrous histiocytoma/undifferentiated pleomorphic sarcoma and dedifferentiated/pleomorphic liposarcoma, were part of the latter cluster and were characterized by relatively heterogeneous profiles, although subclusters herein were identified. A prognostic signature partly characterized by hypoxia-related genes was identified among 89 genetically complex pleomorphic primary STS and could, in a multivariate analysis including established prognostic markers, independently predict the risk of metastasis with a hazard ratio of 2.2 (P = 0.04). Conclusion Diagnostic gene expression profiles linking signaling pathways to the different STS subtypes were demonstrated and a hypoxia-induced metastatic profile was identified in the pleomorphic, high-grade STS. These findings verify diagnostic utility and application of expression data for improved selection of high-risk STS patients.
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| 3. |
- Kresse, Stine H., et al.
(författare)
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Integrative Analysis Reveals Relationships of Genetic and Epigenetic Alterations in Osteosarcoma
- 2012
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Background: Osteosarcomas are the most common non-haematological primary malignant tumours of bone, and all conventional osteosarcomas are high-grade tumours showing complex genomic aberrations. We have integrated genome-wide genetic and epigenetic profiles from the EuroBoNeT panel of 19 human osteosarcoma cell lines based on microarray technologies. Principal Findings: The cell lines showed complex patterns of DNA copy number changes, where genomic copy number gains were significantly associated with gene-rich regions and losses with gene-poor regions. By integrating the datasets, 350 genes were identified as having two types of aberrations (gain/over-expression, hypo-methylation/over-expression, loss/under-expression or hyper-methylation/under-expression) using a recurrence threshold of 6/19 (>30%) cell lines. The genes showed in general alterations in either DNA copy number or DNA methylation, both within individual samples and across the sample panel. These 350 genes are involved in embryonic skeletal system development and morphogenesis, as well as remodelling of extracellular matrix. The aberrations of three selected genes, CXCL5, DLX5 and RUNX2, were validated in five cell lines and five tumour samples using PCR techniques. Several genes were hyper-methylated and under-expressed compared to normal osteoblasts, and expression could be reactivated by demethylation using 5-Aza-2′-deoxycytidine treatment for four genes tested; AKAP12, CXCL5, EFEMP1 and IL11RA. Globally, there was as expected a significant positive association between gain and over-expression, loss and under-expression as well as hyper-methylation and under-expression, but gain was also associated with hyper-methylation and under-expression, suggesting that hyper-methylation may oppose the effects of increased copy number for detrimental genes. Conclusions: Integrative analysis of genome-wide genetic and epigenetic alterations identified dependencies and relationships between DNA copy number, DNA methylation and mRNA expression in osteosarcomas, contributing to better understanding of osteosarcoma biology. © 2012 Kresse et al.
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