| 1. |
- Olsson, Marie, et al.
(författare)
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Effects of extracts of apple peel from organically and integrated production cultivated apples and ursolic acid on cancer cell proliferation
- 2014
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Ingår i: Acta Horticulturae. - 0567-7572 .- 2406-6168. - 9789462610286 ; 1040, s. 227-230
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Konferensbidrag (refereegranskat)abstract
- The effects of extract of apple peel, 'Aroma', organically cultivated or cultivated according to integrated production, on cell proliferation in vitro of colon cancer HT29 cells and breast cancer MCF-7 cells, were investigated. Different sequences of solvents were used, and the inhibiting effect on cancer cell proliferation of the different extracts was investigated. The solvents used were ethanol, methanol, DMSO and hexane in different sequences. The extracts decreased the proliferation of both HT29 and MCF-7 cells, the effect was different for the different extracts, and ethanol showed the highest inhibition effect. The inhibiting effect of the extracts also varied between both apple production methods, and extracts from peels of organically produced apples showed in some cases higher inhibition effects, while sometimes no differences were found. In addition, as ursolic acid, a component of apple peel, has been proposed to inhibit cancer cell proliferation, the inhibiting effect of pure ursolic acid on cancer cell proliferation was compared with the effect of the apple peel solvent fraction with the highest ursolic acid concentration. The inhibiting effect was higher in the apple fraction extract than in pure ursolic acid. Further, a range of different apple cultivars, integrated production and organically cultivated, were analysed by HPLC for their content of ursolic acid to investigate possible differences in concentrations.
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| 2. |
- Jiang, Lin, et al.
(författare)
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Constitutive activation of the ERK pathway in melanoma and skin melanocytes in Grey horses
- 2014
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Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407 .- 1471-2407. ; 14, s. 857-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Constitutive activation of the ERK pathway, occurring in the vast majority of melanocytic neoplasms, has a pivotal role in melanoma development. Different mechanisms underlie this activation in different tumour settings. The Grey phenotype in horses, caused by a 4.6 kb duplication in intron 6 of Syntaxin 17 (STX17), is associated with a very high incidence of cutaneous melanoma, but the molecular mechanism behind the melanomagenesis remains unknown. Here, we investigated the involvement of the ERK pathway in melanoma development in Grey horses.METHODS: Grey horse melanoma tumours, cell lines and normal skin melanocytes were analyzed with help of indirect immunofluorescence and immunoblotting for the expression of phospho-ERK1/2 in comparison to that in non-grey horse and human counterparts. The mutational status of BRAF, RAS, GNAQ, GNA11 and KIT genes in Grey horse melanomas was determined by direct sequencing. The effect of RAS, RAF and PI3K/AKT pathways on the activation of the ERK signaling in Grey horse melanoma cells was investigated with help of specific inhibitors and immunoblotting. Individual roles of RAF and RAS kinases on the ERK activation were examined using si-RNA based approach and immunoblotting.RESULTS: We found that the ERK pathway is constitutively activated in Grey horse melanoma tumours and cell lines in the absence of somatic activating mutations in BRAF, RAS, GNAQ, GNA11 and KIT genes or alterations in the expression of the main components of the pathway. The pathway is mitogenic and is mediated by BRAF, CRAF and KRAS kinases. Importantly, we found high activation of the ERK pathway also in epidermal melanocytes, suggesting a general predisposition to melanomagenesis in these horses.CONCLUSIONS: These findings demonstrate that the presence of the intronic 4.6 kb duplication in STX17 is strongly associated with constitutive activation of the ERK pathway in melanocytic cells in Grey horses in the absence of somatic mutations commonly linked to the activation of this pathway during melanomagenesis. These findings are consistent with the universal importance of the ERK pathway in melanomagenesis and may have valuable implications for human melanoma research.
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| 3. |
- Lindqvist, Breezy Malakkaran, 1978-, et al.
(författare)
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Whole genome DNA methylation signature of HER2-positive breast cancer
- 2014
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Ingår i: Epigenetics. - Austin, USA : Landes Bioscience. - 1559-2294 .- 1559-2308. ; 9:8, s. 1149-1162
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Tidskriftsartikel (refereegranskat)abstract
- In order to obtain a comprehensive DNA methylation signature of HER2-positive breast cancer (HER2+ breast cancer), we performed a genome-wide methylation analysis on 17 HER2+ breast cancer and compared with ten normal breast tissue samples using the Illumina Infinium HumanMethylation450 BeadChip (450K). In HER2+ breast cancer, we found altered DNA methylation in genes involved in multicellular development, differentiation and transcription. Within these genes, we observed an overrepresentation of homeobox family genes, including several genes that have not been previously reported in relation to cancer (DBX1, NKX2-6, SIX6). Other affected genes included several belonging to the PI3K and Wnt signaling pathways. Notably, HER2, AKT3, HK1, and PFKP, genes for which altered methylation has not been previously reported, were also identified in this analysis. In total, we report 69 candidate biomarker genes with maximum differential methylation in HER2+ breast cancer. External validation of gene expression in a selected group of these genes (n = 13) revealed lowered mean gene expression in HER2+ breast cancer. We analyzed DNA methylation in six top candidate genes (AKR1B1, INA, FOXC2, NEUROD1, CDKL2, IRF4) using EpiTect Methyl II Custom PCR Array and confirmed the 450K array findings. Future clinical studies focusing on these genes, as well as on homeobox-containing genes and HER2, AKT3, HK1, and PFKP, are warranted which could provide further insights into the biology of HER2+ breast cancer.
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| 4. |
- Betsholtz, Christer, et al.
(författare)
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PDGF, Pericytes and the Pathogenesis of Idiopathic Basal Ganglia Calcification (IBGC)
- 2014
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Ingår i: Brain Pathology. - : Wiley. - 1015-6305 .- 1750-3639. ; 24:4, s. 387-395
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Tidskriftsartikel (refereegranskat)abstract
- Platelet-derived growth factors (PDGFs) are important mitogens for various types of mesenchymal cells, and as such, they exert critical functions during organogenesis in mammalian embryonic and early postnatal development. Increased or ectopic PDGF activity may also cause or contribute to diseases such as cancer and tissue fibrosis. Until recently, no loss-of-function (LOF) mutations in PDGF or PDGF receptor genes were reported as causally linked to a human disease. This changed in 2013 when reports appeared on presumed LOF mutations in the genes encoding PDGF-B and its receptor PDGF receptor-beta (PDGF-R) in familial idiopathic basal ganglia calcification (IBGC), a brain disease characterized by anatomically localized calcifications in or near the blood microvessels. Here, we review PDGF-B and PDGF-R biology with special reference to their functions in brain-blood vessel development, pericyte recruitment and the regulation of the blood-brain barrier. We also discuss various scenarios for IBGC pathogenesis suggested by observations in patients and genetically engineered animal models of the disease.
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| 5. |
- Degerman, Sofie, et al.
(författare)
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Immortalization of T-Cells Is Accompanied by Gradual Changes in CpG Methylation Resulting in a Profile Resembling a Subset of T-Cell Leukemias
- 2014
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Ingår i: Neoplasia. - : Elsevier BV. - 1522-8002 .- 1476-5586. ; 16:7, s. 606-615
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Tidskriftsartikel (refereegranskat)abstract
- We have previously described gene expression changes during spontaneous immortalization of T-cells, thereby identifying cellular processes important for cell growth crisis escape and unlimited proliferation. Here, we analyze the same model to investigate the role of genome-wide methylation in the immortalization process at different time points pre-crisis and post-crisis using high-resolution arrays. We show that over time in culture there is an overall accumulation of methylation alterations, with preferential increased methylation close to transcription start sites (TSSs), islands, and shore regions. Methylation and gene expression alterations did not correlate for the majority of genes, but for the fraction that correlated, gain of methylation close to TSS was associated with decreased gene expression. Interestingly, the pattern of CpG site methylation observed in immortal T-cell cultures was similar to clinical T-cell acute lymphoblastic leukemia (T-ALL) samples classified as CpG island methylator phenotype positive. These sites were highly overrepresented by polycomb target genes and involved in developmental, cell adhesion, and cell signaling processes. The presence of non-random methylation events in in vitro immortalized T-cell cultures and diagnostic T-ALL samples indicates altered methylation of CpG sites with a possible role in malignant hematopoiesis.
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| 6. |
- Nilsson, Torbjörn K., et al.
(författare)
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MTHFR polymorphisms and serum cobalamin affect plasma homocysteine concentrations differentially in females and males
- 2014
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Ingår i: Molecular Medicine Reports. - : Spandidos Publications. - 1791-2997 .- 1791-3004. ; 10:5, s. 2706-2712
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Tidskriftsartikel (refereegranskat)abstract
- A total of 523 subjects (297 females and 226 males) from the Canary Islands Nutrition Study (ENCA) were studied in order to examine the effect of the MTHFR 677C>T, 1298A>C and 1793G>A polymorphisms, adjusted for age, serum (5)-folate and S-cobalamin levels, on total plasma homocysteine concentrations (tHcy). Genotyping was performed with Pyrosequencing(R) technology. The MTHFR 677T-allele was associated with increased tHcy concentrations only in males (P=0.005). The MTHFR 1298C-allele was found to be associated with higher tHcy levels but similarly, only in males (P=0.025). The MTHFR 1793A-allele was associated with decreased tHcy concentrations in the younger males (P=0.042). A haplotype-based approach was marginally superior in explaining the genetic interaction of the MTHFR polymorphisms on tHcy plasma levels (R-2 0.352 vs. 0.342 for a simple genotype-based approach). A nutrigenetic interaction between the MTHFR 677C>T genotype and S-cobalamin on tHcy levels was demonstrated in both genders. The increase in tHcy was more pronounced with decreasing S-cobalamin quintiles in 677TT homozygotes (P=0.005 for males and P=0.015 for females) than with decreasing S-folate quintiles (P for trend not significant). It was concluded that gene-nutrient interactions may differ depending on the sex and age of the subjects. The transferability of gene-nutrient interactions from one community to others may therefore be limited not only by different food patterns but also by different ages, genders and genotype distributions.
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| 7. |
- Schock, Helena, 1984-, et al.
(författare)
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Early pregnancy sex steroids and maternal risk of epithelial ovarian cancer
- 2014
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Ingår i: Endocrine-Related Cancer. - : Society for Endocrinology. - 1351-0088 .- 1479-6821. ; 21:6, s. 831-844
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Tidskriftsartikel (refereegranskat)abstract
- Well-established associations between reproductive characteristics and epithelial ovarian cancer (EOC) support an involvement of sex steroid hormones in the etiology of EOC. Limited previous studies have evaluated circulating androgens and the risk of EOC, and estrogens and progesterone have been investigated in only one of the previous studies. Furthermore, there is little data on potential heterogeneity in the association between circulating hormones and EOC by histological subgroup. Therefore, we conducted a nested case-control study within the Finnish Maternity Cohort and the Northern Sweden Maternity Cohort to investigate the associations between circulating pre-diagnostic sex steroid concentrations and the histological subtypes of EOC. We identified 1052 EOC cases among cohort members diagnosed after recruitment (1975-2008) and before March 2011. Up to three controls were individually matched to each case (n=2694). Testosterone, androstenedione, 17-hydroxyprogesterone (17-OHP), progesterone, estradiol (E-2), and sex hormone-binding globulin levels were measured in serum samples collected during the last pregnancy before EOC diagnosis. We used conditional logistic regression to estimate odds ratios (ORs) and 95% CIs. Associations between hormones and EOC differed with respect to tumor histology and invasiveness. Sex steroid concentrations were not associated with invasive serous tumors; however, doubling of testosterone and 17-OHP concentration was associated with approximately 40% increased risk of borderline serous tumors. A doubling of androgen concentrations was associated with a 50% increased risk of mucinous tumors. The risk of endometrioid tumors increased with higher E-2 concentrations (OR: 1.89 (1.20-2.98)). This large prospective study in pregnant women supports a role of sex steroid hormones in the etiology of EOC arising in the ovaries.
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| 8. |
- Kyrø, Cecilie, et al.
(författare)
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Plasma Alkylresorcinols, Biomarkers of Whole-Grain Wheat and Rye Intake, and Incidence of Colorectal Cancer
- 2014
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Ingår i: Journal of the National Cancer Institute. - : Oxford University Press. - 0027-8874 .- 1460-2105. ; 106:1, s. djt352-
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Tidskriftsartikel (refereegranskat)abstract
- Background Few studies have investigated the association between whole-grain intake and colorectal cancer. Because whole-grain intake estimation might be prone to measurement errors, more objective measures (eg, biomarkers) could assist in investigating such associations. Methods The association between alkylresorcinols, biomarkers of whole-grain rye and wheat intake, and colorectal cancer incidence were investigated using prediagnostic plasma samples from colorectal cancer case patients and matched control subjects nested within the European Prospective Investigation into Cancer and Nutrition. We included 1372 incident colorectal cancer case patients and 1372 individual matched control subjects and calculated the incidence rate ratios (IRRs) for overall and anatomical subsites of colorectal cancer using conditional logistic regression adjusted for potential confounders. Regional differences (Scandinavia, the Mediterranean, Central Europe) were also explored. Results High plasma total alkylresorcinol concentration was associated with lower incidence of distal colon cancer; the adjusted incidence rate ratio of distal colon cancer for the highest vs lowest quartile of plasma total alkylresorcinols was 0.48 (95% confidence interval [CI] = 0.28 to 0.83). An inverse association between plasma total alkylresorcinol concentrations and colon cancer was found for Scandinavian participants (IRR per doubling = 0.83; 95% CI = 0.70 to 0.98). However, plasma total alkylresorcinol concentrations were not associated with overall colorectal cancer, proximal colon cancer, or rectal cancer. Plasma alkylresorcinols concentrations were associated with colon and distal colon cancer only in Central Europe and Scandinavia (ie, areas where alkylresorcinol levels were higher). Conclusions High concentrations of plasma alkylresorcinols were associated with a lower incidence of distal colon cancer but not with overall colorectal cancer, proximal colon cancer, and rectal cancer.
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