| 1. |
- Berglund, Helena, et al.
(författare)
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Associations of invasive alien species and other threats to IUCN Red List species (Chordata: vertebrates)
- 2013
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Ingår i: Biological Invasions. - : Springer Science and Business Media LLC. - 1387-3547 .- 1573-1464. ; 15:5, s. 1169-1180
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Tidskriftsartikel (refereegranskat)abstract
- Apart from acting synergistically or additively, threats to species may be associated or disassociated. Here we link global data on threatened Chordata species, mainly birds, mammals, and amphibians, with a probabilistic methodology to test whether the impact from invasive alien species co-occurs purely randomly, associated, or disassociated with impact from nine other major threats to biodiversity listed in the International Union for Conservation of Nature Red List database. Impacts from several of the other threats, in particular from natural disasters, are associated with the impact from invasive alien species. Three of the threats of anthropogenic origin, namely habitat loss, harvesting, and human disturbance, co-occur randomly with impact from invaders, and we suggest several explanations to this unexpected relationship, such as ambiguous evidence for associations between them and human-induced disturbances. Impact from invasive alien predators has a strong association with impact from native predators, indicating that similarity in autecology affects co-occurrences between threats. The threat from invasive predators is disassociated from intrinsic factors on islands, probably because species suffering from for instance inbreeding problems have low densities and rarely encounter invasive alien predators. The analysis of co-occurrence of impact from invasive alien species and other threats is a first step to understand and mitigate vulnerability of a community to the simultaneous exposure to invasive alien species and other threats. Association or disassociation between threats may depend on correlations between exposures and sensitivity to the threats or on the presence of one threat increasing or decreasing the sensitivity to another.
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| 2. |
- Berglund, Helena, et al.
(författare)
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Endemism Predicts Intrinsic Vulnerability to Nonindigenous Species on Islands.
- 2009
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Ingår i: American Naturalist. - : University of Chicago Press. - 0003-0147 .- 1537-5323. ; 174:1, s. 94-101
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Tidskriftsartikel (refereegranskat)abstract
- Abstract: While numerous efforts have been made to identify and quantify factors controlling invasibility of biological communities, less attention has been given to analyzing the expressions of vulnerability to nonindigenous species (NIS). Using the International Union for the Conservation of Nature and Natural Resources Red List database for birds, mammals, and amphibians and the Invasive Species Specialist Group global invasive species database as sources of information, we developed a new indicator for the relative intrinsic vulnerability of islands to NIS. It was calculated from the residuals to the global relationship between the impact of NIS and their exposure to the islands. The impact of NIS was expressed as the proportion of indigenous species threatened by NIS, and the exposure was the number of invasive NIS per number of native species. The residuals corresponded to the variability in impact, about 60%, that was not explained by exposure. The proportion of endemic species on the islands was positively correlated with the relative intrinsic vulnerability and explained about 60% of its variability. The robust relationship between endemism and intrinsic vulnerability reinforces the role of long-term isolation for the fate of island indigenous species to biological invasions and is useful in identifying vulnerable environments without having a specific invader in mind.
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| 3. |
- Halin Bergström, Sofia, et al.
(författare)
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Prostate tumors downregulate microseminoprotein-beta (MSMB) in the surrounding benign prostate epithelium and this response is associated with tumor aggressiveness
- 2018
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Ingår i: The Prostate. - : Wiley. - 0270-4137 .- 1097-0045. ; 78:4, s. 257-265
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Tidskriftsartikel (refereegranskat)abstract
- Background: Microseminoprotein-beta (MSMB) is a major secretory product from prostate epithelial cells. MSMB synthesis is decreased in prostate tumors in relation to tumor grade. MSMB levels are also reduced in the circulation and MSMB is therefore used as a serum biomarker for prostate cancer. We hypothesized that cancers induce a reduction in MSMB synthesis also in the benign parts of the prostate, and that the magnitude of this response is related to tumor aggressiveness. Reduced levels of MSMB in the circulation could therefore be a consequence of reduced MSMB expression not only in tumor tissue but also in the benign prostate tissue.Methods: MSMB expression was analyzed in prostatectomy specimens from 36 patients using immunohistochemistry and qRT-PCR. MSMB expression in the benign prostate tissue was analyzed in relation to Gleason score, tumor stage, and distance to the tumor. Furthermore, Dunning rat prostate tumors with different aggressiveness were implanted into the prostate of Copenhagen rats to study if this affected the MSMB expression in the tumor-adjacent benign rat prostate tissue.Results: In prostatectomy specimens, MSMB expression was reduced in prostate tumors but also in the tumor-adjacent benign parts of the prostate. The reduction in tumor MSMB was related to tumor grade and stage, and the reduction in the benign parts of the prostate to tumor grade, stage, and distance to the tumor. Implantation of Dunning cancer cells into the rat prostate resulted in reduced MSMB protein levels in the tumor-adjacent benign prostate tissue. Rapidly growing and metastatic MatLyLu tumors had a more pronounced effect than slow-growing non-metastatic G tumors.Conclusion: Our data suggest that aggressive prostate tumors suppress MSMB synthesis in the benign prostate and that this could explain why serum levels of MSMB are decreased in prostate cancer patients. This study suggests that markers for aggressive cancer can be found among factors altered in parallel in prostate tumors and in the adjacent benign tissue.
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| 4. |
- Järemo, Helena, et al.
(författare)
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Investigating microRNA Profiles in Prostate Cancer Bone Metastases and Functional Effects of microRNA-23c and microRNA-4328
- 2023
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Ingår i: Cancers. - : MDPI. - 2072-6694. ; 15:9
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Tidskriftsartikel (refereegranskat)abstract
- MicroRNAs (miRNAs) are aberrantly expressed in prostate cancer (PC), but comprehensive knowledge about their levels and function in metastatic PC is lacking. Here, we explored the differential expression of miRNA profiles during PC progression to bone metastasis, and further focused on the downregulation of miRNA-23c and -4328 and their impact on PC growth in experimental models. Using microarray screening, the levels of 1510 miRNAs were compared between bone metastases (n = 14), localized PC (n = 7) and benign prostate tissue (n = 7). Differentially expressed miRNAs (n = 4 increased and n = 75 decreased, p < 0.05) were identified, of which miRNA-1, -23c, -143-3p, -143-5p, -145-3p, -205-5p, -221-3p, -222-3p and -4328 showed consistent downregulation during disease progression (benign > localized PC > bone metastases). The downregulation of miRNA-23c and -4328 was confirmed by reverse transcription and quantitative polymerase chain reaction analysis of 67 metastasis, 12 localized PC and 12 benign prostate tissue samples. The stable overexpression of miRNA-23c and -4328 in the 22Rv1 and PC-3 cell lines resulted in reduced PC cell growth in vitro, and in the secretion of high levels of miRNA-23c (but not -4328) in extracellular vesicles. However, no tumor suppressive effects were observed from miRNA-23c overexpression in PC-3 cells subcutaneously grown in mice. In conclusion, bone metastases display a profound reduction of miRNA levels compared to localized PC and benign disease. The downregulation of those miRNAs, including miRNA-23c and -4328, may lead to a loss of tumor suppressive effects and provide biomarker and therapeutic possibilities that deserve to be further explored.
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| 5. |
- Järemo, Helena, 1988-
(författare)
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MicroRNA expression profiles in prostate cancer bone metastases : functional effects of microRNA-23c, -375, and -4328
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Non-coding microRNAs (miRNAs) function as post-transcriptional regulators of gene expression by interacting with messenger RNA. Dysregulation of miRNAs has many possible consequences, including tumor-suppressive or -promoting ones, and restoring or preventing the effects of miRNA alteration has therapeutic potential.Metastatic prostate cancer (PC) spreads to the bone and is treated with castration therapy. Eventually, metastases relapse into castration-resistant PC (CRPC) growth. Recently, our laboratory described metastatic PC subtypes, termed MetA-C, defined based on transcriptomic differences and linked to different morphology and prognosis. Patients with MetB metastases have particularly poor prognosis.The overall aim of the thesis was to identify novel biomarkers and therapeutic targets for metastatic PC, with a focus on miRNAs. The specific aims were to: (1) identify miRNAs associated with PC progression into bone metastasis, and their functional roles; (2) verify the MetA-C subtypes, their prognostic importance, and their relation to genetic profiles in independent validation cohorts; (3) explore miRNA expression profiles of PC bone metastases, specifically in relation to the MetA-C subtypes, and whether specific miRNAs show potential to inhibit the aggressive MetB subtype.Study 1: Differentially expressed miRNAs (n=79) were identified by microarray analysis by comparing miRNA levels in bone metastatic (n=14) or localized PC (n=7) samples to benign samples (n=7). Downregulation of miRNA-23c and -4328 was verified by qRT-PCR analysis, including a larger cohort of bone metastases (n=67). Overexpression of miRNA-23c or -4328 in PC cells resulted in attenuated cell growth in vitro. High levels of miRNA-23c were detected in extracellular vesicles shed from overexpressing cells. Overexpression of miRNA-23c did not obviously affect tumor growth or angiogenesis in vivo. Study 2: The existence and prognostic value of the MetA-C subtypes was verified by transcriptomic analysis of bone metastasis samples (n=103), and by subtyping publicly available data from metastatic samples (n=573) from external patient cohorts. The MetB subtype was associated with high tumor-cell proliferation, low androgen receptor activity, and poor prognosis in all cohorts, and provided independent prognostic information in addition to genetic aberrations.Study 3: The miRNA profiles of 96 bone metastasis samples from Study 2 were examined using microarray analysis. Four sample clusters not obviously related to the MetA-C subtypes were observed. Expression levels of miRNA-375, however, were inversely related to MetB. MiRNA-375 overexpression in C4-2B resulted in a cellular switch of subtype, from being dominant MetB to dominant MetA. In parallel, reduced cell growth and signs of increased cell adhesion were observed.In conclusion, altered miRNA profiles may contribute to progression of PC into bone metastasis, and to the development of different metastasis subtypes. The MetB subtype is associated with poor prognosis and low expression of miRNA-375. Therapy stratification based on the MetA-C subtypes should be considered in the future. Restoration of miRNA-375 in MetB tumors may offer a novel treatment option.
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| 6. |
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| 7. |
- Thysell, Elin, et al.
(författare)
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Clinical and biological relevance of the transcriptomic-based prostate cancer metastasis subtypes MetA-C
- 2022
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Ingår i: Molecular Oncology. - : Wiley. - 1574-7891 .- 1878-0261. ; 16:4, s. 846-859
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Tidskriftsartikel (refereegranskat)abstract
- To improve treatment of metastatic prostate cancer, the biology of metastases needs to be understood. We recently described three subtypes of prostate cancer bone metastases (MetA-C), based on differential gene expression. The aim of this study was to verify the clinical relevance of these subtypes and to explore their biology and relations to genetic drivers. Freshly-frozen metastasis samples were obtained as hormone-naive (n = 17), short-term castrated (n = 21), or castration-resistant (n = 65) from a total of 67 patients. Previously published sequencing data from 573 metastasis samples were also analyzed. Through transcriptome profiling and sample classification based on a set of predefined MetA-C-differentiating genes, we found that most metastases were heterogeneous for the MetA-C subtypes. Overall, MetA was the most common subtype, while MetB was significantly enriched in castration-resistant samples and in liver metastases, and consistently associated with poor prognosis. By gene set enrichment analysis, the phenotype of MetA was described by high androgen response, protein secretion and adipogenesis, MetB by high cell cycle activity and DNA repair, and MetC by epithelial-to-mesenchymal transition and inflammation. The MetB subtype demonstrated single nucleotide variants of RB transcriptional corepressor 1 (RB1) and loss of 21 genes at chromosome 13, including RB1, but provided independent prognostic value to those genetic aberrations. In conclusion, a distinct set of gene transcripts can be used to classify prostate cancer metastases into the subtypes MetA-C. The MetA-C subtypes show diverse biology, organ tropism, and prognosis. The MetA-C classification may be used independently, or in combination with genetic markers, primarily to identify MetB patients in need of complementary therapy to conventional androgen receptor-targeting treatments.
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| 8. |
- Voss, Gjendine, et al.
(författare)
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Regulation of cell-cell adhesion in prostate cancer cells by microRNA-96 through upregulation of E-Cadherin and EpCAM
- 2020
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Ingår i: Carcinogenesis. - : Oxford University Press. - 0143-3334 .- 1460-2180. ; 41:7, s. 865-874
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Tidskriftsartikel (refereegranskat)abstract
- Prostate cancer is one of the most common cancers in men, yet the biology behind lethal disease progression and bone metastasis is poorly understood. In this study, we found elevated levels of microRNA-96 (miR-96) in prostate cancer bone metastasis samples. To determine the molecular mechanisms by which miR-96 deregulation contributes to metastatic progression, we performed an Argonaute2-immunoprecipitation assay, in which mRNAs associated with cell-cell interaction were enriched. The expression of two cell adhesion molecules, E-Cadherin and EpCAM, was upregulated by miR-96, and potential targets sites were identified in the coding sequences of their mRNAs. We further showed that miR-96 enhanced cell-cell adhesion between prostate cancer cells as well as their ability to bind to osteoblasts. Our findings suggest that increased levels of miR-96 give prostate cancer cells an advantage at forming metastases in the bone microenvironment due to increased cell-cell interaction. We propose that miR-96 promotes bone metastasis in prostate cancer patients by facilitating the outgrowth of macroscopic tumours in the bone.
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