| 1. |
- Farkas, Sanja A., 1983-, et al.
(författare)
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DNA methylation and expression of the folate transporter genes in colorectal cancer
- 2015
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Ingår i: Tumor Biology. - : S. Karger. - 1010-4283 .- 1423-0380. ; 36:7, s. 5581-5590
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Tidskriftsartikel (refereegranskat)abstract
- Folate has a central role in the cell metabolism. This study aims to explore the DNA methylation pattern of the folate transporter genes FOLR1, PCFT, and RFC1 as well as the corresponding protein expressions in colorectal cancer (CRC) tissue and adjacent non-cancerous mucosa (ANCM). Our results showed statistically significant differences in the DNA-methylated fraction of all three genes at several gene regions; we identified three differentially methylated CpG sites in the FOLR1 gene, five CpG sites in the PCFT gene, and six CpG sites in the RFC1 gene. There was a pronounced expression of the FR alpha and RFC proteins in both the CRC and ANCM tissues, though the expression was attenuated in cancer compared to the paired ANCM tissues. The PCFT protein was undetectable or expressed at a very low level in both tissue types. Higher methylated fractions of the CpG sites 3-5 in the RFC1 gene were associated with a lower protein expression, suggestive of epigenetic regulation by DNA methylation of the RFC1 gene in the colorectal cancer. Our results did not show any association between the RFC and FR alpha protein expression and tumor stage, TNM classification, or tumor location. In conclusion, this is the first study to simultaneously evaluate both DNA methylation and protein expression of all three folate transporter genes, FOLR1, PCFT, and RFC1, in colorectal cancer. The results encourage further investigation into the possible prognostic implications of folate transporter expression and DNA methylation.
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| 2. |
- Farkas, Sanja A., 1983-, et al.
(författare)
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DNA methylation and expression of the folate transporting genes in colorectal cancer
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- This study investigated the DNA methylation pattern and protein expression of the FOLR1, PCFT, and RFC1 genes in colorectal cancer (CRC) tissue. Our results showed statistically significant differences in the DNA methylated fraction of all three genes at several gene regions, we identified 3 differentially methylated CpG sites in the FOLR1 gene, 5 CpG sites in the PCFT gene, and 6 CpG sites in the RFC1 gene. We observed a pronounced expression of the FRα and RFC proteins in both the cancer and normal tissues, though the proteins were moderately expressed in cancer compared to the high expression in the paired healthy mucosa. The PCFT protein was undetectable or expressed very low in both tissues. Higher methylated fractions of the CpG sites 3-5 in the RFC1 gene were associated with a lower protein expression. When analyzing the association between DNA methylation and tumor characteristics (differentiation, location, primary tumor stage and lymph node involvement) we detected lower methylated fraction of specific CpG sites in the RFC1 gene in CRC located in the distal colon and rectum compared to the proximal colon. In the FOLR1 gene, we found CpG sites with a lower methylated fraction of colorectal cancers with the primary tumor stage 4 (pT4) compared to the pT2 and pT3 stages. Our results did not show association between the RFC and FRα protein expression and tumor stage, TNM classification or tumor location. In conclusion, these data suggest that there is a possible epigenetic regulation by DNA methylation of the RFC1 gene in the colorectal cancer.
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| 3. |
- Farkas, Sanja A., 1983-, et al.
(författare)
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DNA methylation changes in genes frequently mutated in sporadic colorectal cancer and in the DNA repair and Wnt/beta-catenin signaling pathway genes
- 2014
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Ingår i: Epigenomics. - : Future Medicine. - 1750-1911. ; 6:2, s. 179-191
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Tidskriftsartikel (refereegranskat)abstract
- Aim: The onset and progression of colorectal cancer (CRC) involves a cascade of genetic and/or epigenetic events. The aim of the present study was to address the DNA methylation status of genes relevant in colorectal carcinogenesis and its progression, such as genes frequently mutated in CRC, genes involved in the DNA repair and Wnt signaling pathway.Material & methods: We analyzed methylation status in totally 160 genes in 12 paired colorectal tumors and adjacent healthy mucosal tissues using the Illumina Infinium Human Methylation 450 BeadChip.Results: We found significantly aberrant methylation in 23 genes (NEIL1, NEIL3, DCLRE1C, NHEJ1, GTF2H5, CCNH, CTNNB1, DKK2, DKK3, FZD5 LRP5, TLE3, WNT2, WNT3A, WNT6, TCF7L1, CASP8, EDNRB1, GPC6, KIAA1804, MYO1B, SMAD2 and TTN). External validation by mRNA expression showed a good agreement between hypermethylation in cancer and down-regulated mRNA expression of the genes EDNRB1, GPC6 and SMAD2, and between hypomethylation and up-regulated mRNA expression of the CASP8 and DCLRE1C genes.Conclusion: Aberrant methylation of the DCLRE1C and GPC6 genes are presented here for the first time and are therefore of special interest for further validation as novel candidate biomarker genes in CRC, and merit further validation with specific assays.
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| 4. |
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| 5. |
- Farkas, Sanja A., 1983-, et al.
(författare)
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Epigenetic alterations in folate transport genes in placental tissue from fetuses with neural tube defects and in leukocytes from subjects with hyperhomocysteinemia
- 2013
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Ingår i: Epigenetics. - : Informa UK Limited. - 1559-2294 .- 1559-2308. ; 8:3, s. 303-316
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Tidskriftsartikel (refereegranskat)abstract
- The objectives of this study were to identify tissue-specific differentially methylated regions (T-DMR's) in the folate transport genes in placental tissue compared with leukocytes, and from placental tissues obtained from normal infants or with neural tube defects (NTDs). Using pyrosequencing, we developed methylation assays for the CpG islands (CGIs) and the CGI shore regions of the folate receptor a (FOLR1), proton-coupled folate transporter (PCFT) and reduced folate carrier 1 (RFC1) genes. The T-DMRs differed in location for each gene and the difference in methylation ranged between 2 and 54%. A higher T-DMR methylated fraction was associated with a lower mRNA level of the FOLR1 and RFC1 genes. Methylation fractions differed according to RFC1 80G > A genotype in the NTD cases and in leukocytes from subjects with high total plasma homocysteine (tHcy). There were no differences in methylated fraction of folate transporter genes between NTD cases and controls. We suggest that T-DMRs participate in the regulation of expression of the FOLR1 and RFC1 genes, that the RFC1 80G > A polymorphism exerts a gene-nutrition interaction on DNA methylation in the RFC1 gene, and that this interaction appears to be most prominent in NTD-affected births and in subjects with high tHcy concentrations.
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| 6. |
- Farkas, Sanja A., 1983-, et al.
(författare)
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Epigenetic changes as prognostic predictors in endometrial carcinomas
- 2017
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Ingår i: Epigenetics. - : Informa UK Limited. - 1559-2294 .- 1559-2308. ; 12:1, s. 19-26
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Tidskriftsartikel (refereegranskat)abstract
- Endometrial carcinoma is one of the most frequent gynecological malignancies of the female. The diagnostic and prognostic markers for the high-risk subgroups with unfavorable prognosis are under intense debate worldwide, and, therefore, the aim of this study was to identify new potential DNA methylation markers for the high-risk groups. We used the Illumina Infinium HumanMethylation450 BeadChip to analyze the DNA methylation pattern and investigated its association with clinicopathological features important for defining the high-risk (FIGO-grade 3) and low-risk (FIGO-grade 1) groups of patients with endometrial cancer (n = 31 and n = 39, respectively). We identified specific DNA methylation signature in high-risk endometrial tumors, and potential molecular biomarker genes (TBX2, CHST11, and NID2) associated with unfavorable clinical predictive and prognostic factors.
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| 7. |
- Farkas, Sanja A., 1983-, et al.
(författare)
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Epigenetic changes as prognostic predictors in endometrial carcinomas
- 2018
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Konferensbidrag (refereegranskat)abstract
- Objective: In Sweden, endometrial carcinoma is number five among female cancers, with 1,400 new cases per year. The diagnostic and prognostic markers for the high-risk subgroups with unfavorable prognosis are under intense debate worldwide. The aim of the present study was to address the epigenetic differences in a consecutive series of endometrial carcinomas comprising a low-risk group (FIGO-grade 1) and a high-risk group (FIGO-grade 3) with highly significant different treatment outcomes and survival rates.Method: We used the Illumina Infinium HumanMethylation450 BeadChip to analyze the DNA methylation pattern and investigated its association with clinicopathological features important for defining the high-risk (FIGO-grade 3) and low-risk (FIGO-grade 1) groups of patients with endometrial cancer.Results: We identified 2,224 differentially methylated CpG sites. Gene ontology analysis classified the hypomethylated genes in the high-risk group were to cell adhesion and membrane, and the hypomethylated genes to cell adhesion. Increasing methylation level in FIGO-grade 3 cancers was significantly (P < 0.01) associated with advanced tumor stage for CpG sites located in the TBX2, CHST11, LRP5, and CIZ1/ DNM1 genes.Conclusion: Our study identified specific DNA methylation signature in low-risk and high-risk endometrial tumors, and potential molecular biomarker genes associated with unfavorable clinical predictive and prognostic factors.
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| 8. |
- Farkas, Sanja A., 1983-, et al.
(författare)
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Genome-wide DNA methylation assay reveals novel candidate biomarker genes in cervical cancer
- 2013
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Ingår i: Epigenetics. - : Informa UK Limited. - 1559-2294 .- 1559-2308. ; 8:11, s. 1213-1225
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Tidskriftsartikel (refereegranskat)abstract
- The oncogenic human papilloma viruses (HPVs) are associated with precancerous cervical lesions and development of cervical cancer. The DNA methylation signatures of the host genome in normal, precancerous and cervical cancer tissue may indicate tissue-specific perturbation in carcinogenesis. The aim of this study was to identify new candidate genes that are differentially methylated in squamous cell carcinoma compared with DNA samples from cervical intraepithelial neoplasia grade 3 (CIN3) and normal cervical scrapes. The Illumina Infinium HumanMethylation450 BeadChip method identifies genome-wide DNA methylation changes in CpG islands, CpG shores and shelves. Our findings showed an extensive differential methylation signature in cervical cancer compared with the CIN3 or normal cervical tissues. The identified candidate biomarker genes for cervical cancer represent several types of mechanisms in the cellular machinery that are epigenetically deregulated by hypermethylation, such as membrane receptors, intracellular signaling and gene transcription. The results also confirm extensive hypomethylation of genes in the immune system in cancer tissues. These insights into the functional role of DNA methylome alterations in cervical cancer could be clinically applicable in diagnostics and prognostics, and may guide the development of new epigenetic therapies.
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| 9. |
- Gasperov, Nina Milutin, et al.
(författare)
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Epigenetic activation of immune genes in cervical cancer
- 2014
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Ingår i: Immunology Letters. - : Elsevier. - 0165-2478 .- 1879-0542. ; 162:2, s. 256-257
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Tidskriftsartikel (refereegranskat)abstract
- Immune system provides us protection from infectious pathogens and tumors formation during lifetime. Cervical cancer (CC), and its cause, human papillomavirus (HPV) are both challenges for the immune system. We present here evidence of epigenetic activation of immune system genes in CC. Illumina Infinium Human Methylation 450 K BeadChip identified genes, which were all significantly hypomethylated in CC tissue versus normal tissue. The GeneMANIA computer program identified a tight network between those genes. The most strongly correlated genes based on their function are immune effectors' process (AIM2, BST2, BTN3A3, and IL12RB1) and response to virus related genes (AIM2, BST2, and IL12RB1). Thus, activation of those genes through demethylation is probably triggered by HPV oncogenes. In conclusion, the immune system of women who do not develop CC is probably activated earlier through DNA demethylation.
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| 10. |
- Isaksson, Helena S., 1978-, et al.
(författare)
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Whole genome microarray expression analysis in blood leucocytes identifies pathways linked to signs and symptoms of a patient with hypercalprotectinaemia and hyperzincaemia
- 2018
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Ingår i: Clinical and Experimental Immunology. - : Wiley-Blackwell Publishing Inc.. - 0009-9104 .- 1365-2249. ; 191:2, s. 240-251
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Tidskriftsartikel (refereegranskat)abstract
- A child, 2 years with the "hypercalprotectinemia with hyperzincemia" clinical syndrome presented with atypical symptoms and signs, notably persistent fever of around 38°C, thrombocythaemia of >700 x 10(9) /L, and a predominance of persistent intestinal symptoms. In an effort to find a cure by identifying the dysregulated pathways we analyzed whole-genome mRNA expression by the Affymetrix HG U133 PLUS 2.0 array on three occasions 3 to 5 months apart. Major upregulation was demonstrated for the JAK/STAT pathway including in particular CD177, S100A8, S100A9, and S100A12, accounting for the thrombocytosis; a large number of interleukins, their receptors, and activators, accounting for the febrile apathic state; and the HMBG1 gene, possibly accounting for part of the intestinal symptoms. These results show that gene expression array technology may assist the clinician in the diagnostic workup of individual patients with suspected syndromal states of unknown origin, and the expression data can guide the selection of optimal treatment directed at the identified target pathways.
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| 11. |
- Koskela, Anita, 1979-, et al.
(författare)
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Evaluation of Microsatellite instability score from GMS560 DNA panel
- 2022
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Microsatellite instability is characterised by gains or losses of nucleotides in short tandem repeat sequences, microsatellites, dispersed throughout the human genome. Microsatellite instability status is a molecular fingerprint for DNA mismatch repair deficiency. Clinical detection of microsatellite instability status is important for identifying inherited disease in patients with colorectal and endometrial cancer but has also a prognostic value for survival and prediction of treatment response. Lately, microsatellite instability has been used as a tumor agnostic biomarker that predicts response to immune checkpoint inhibitors. To identify microsatellite instability status clinically, PCR and immunohistochemistry have been the gold standard. On the contrary, next generation sequencing provide simultaneous accession of large number of microsatellite loci and can be combined with detection of several other biomarkers. The national collaboration Genome Medicine Sweden have developed a solid tumour gene panel composed of 560 cancer associated genes with integrated microsatellite instability score. Our aim was to validate the microsatellite instability status based on microsatellite instability score from GMS560 DNA panel against the clinically used methods. Extracted DNA (100 ng) from formalin fixed paraffin embedded tissue sections with various tumour cell content >10% were analysed. During target enrichment sequencing analysis, allelic distribution from 5000 microsatellite markers were calculated by MSIsensor Pro to generate an instability score. The cohort consisted of microsatellite instable verified colorectal cancer samples (n=20), microsatellite stable solid tumour material (n=60). Preliminary results generated a microsatellite instability score for the colorectal cancer samples with a mean of 26.5 % (CI: 23.4-29.6, range: 16.9-32.3). Microsatellite stable tumour samples had a mean microsatellite instability score of 1.5 % (CI: 0.93-2.07, range: 1-4.45). In conclusion, we found the microsatellite instability score from GMS560 DNA panel to be both diagnostically sensitive and specific for determining MSI status due to obvious separation in instability.
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| 12. |
- Lindqvist, Breezy Malakkaran, et al.
(författare)
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DNA methylation pattern of the SLC25A43 gene in breast cancer
- 2012
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Ingår i: Epigenetics. - Austin, USA : Landes Bioscience. - 1559-2294 .- 1559-2308. ; 7:3, s. 300-306
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Tidskriftsartikel (refereegranskat)abstract
- Solute carrier family 25A member 43 (SLC25A43) gene is a putative tumor suppressor gene that undergoes loss of heterozygosity (LOH) in human epidermal growth factor receptor 2 (HER2) positive breast cancer. Also, knockdown of SLC25A43 in cell lines influences cell turnover and metabolism. Absence of mutations in this gene in breast cancers prompted us to study methylation as an alternate mechanism for gene inactivation of this X encoded gene. Quantification of CpG site methylation using pyrosequencing was performed upstream of the SLC25A43 gene and at its 5' end in a cohort of breast tumor tissues (n = 80, HER2 positive or negative) with different SLC25A43 gene deletion status. Compared with control tissue, cancer tissues had lower levels of methylation at the 5' and 3' shores of the gene. Cancer tissues with no deletion in the SLC25A43 gene (Del(-)) had higher methylation in the CpG island (CGI) of the gene than cancers carrying the deletion (Del(+)). Methylation in the CGI of the SLC25A43 gene was negatively correlated with age at diagnosis. In HER2 positive breast cancer, ER negativity and lymph node positivity was associated with higher methylation in the CGI and in the adjacent shores of this gene. Our results suggest that methylation in the CGI of the SLC25A43 gene could be an alternate mechanism of gene silencing in the absence of LOH. Also, associations between site-specific methylation and clinicopathological parameters suggest that epigenetic changes in SLC25A43 gene could be of importance in breast carcinogenesis.
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| 13. |
- Vymetalkova, Veronika, et al.
(författare)
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Epigenome-wide analysis of DNA methylation reveals a rectal cancer-specific epigenomic signature
- 2016
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Ingår i: Epigenomics. - London, United Kingdom : Future Medicine Ltd.. - 1750-1911 .- 1750-192X. ; 8:9, s. 1193-1207
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Tidskriftsartikel (refereegranskat)abstract
- Aim: The aim of the present study is to address a genome-wide search for novel methylation biomarkers in the rectal cancer (RC), as only scarce information on methylation profile is available.Materials and methods: We analyzed methylation status in 25 pairs of RC and adjacent healthy mucosa using the Illumina Human Methylation 450 BeadChip.Results: We found significantly aberrant methylation in 33 genes. After validation of our results by pyrosequencing, we found a good agreement with our findings. The BPIL3 and HBBP1 genes resulted hypomethylated in RC, whereas TIFPI2, ADHFE1, FLI1 and TLX1 were hypermethylated. An external validation by TCGA datasets confirmed the results.Conclusion: Our study, with external validation, has demonstrated the feasibility of using specific methylated DNA signatures for developing biomarkers in RC.
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