| 1. |
- Cederquist, Kristina, et al.
(författare)
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Two Swedish founder MSH6 mutations, one nonsense and one missense, conferring high cumulative risk of Lynch syndrome.
- 2005
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Ingår i: Clinical Genetics. - : Wiley. - 0009-9163 .- 1399-0004. ; 68:6, s. 533-541
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Tidskriftsartikel (refereegranskat)abstract
- Lynch syndrome, or hereditary non-polyposis colorectal cancer (HNPCC), is a cancer susceptibility syndrome caused by germline mutations in mismatch-repair genes, predominantly MLH1, MSH2 and MSH6. A majority of the mutations reported are truncating, but for MSH6, missense mutations constitute over one third. Few have been proven pathogenic in functional studies or shown to segregate in families. In this study, we show segregation of the putative pathogenic MSH6 missense mutation c.1346T>C p.Leu449Pro with microsatellite instability-high Lynch syndrome-related tumours lacking MSH6 expression in a large 17th century pedigree. Another large family with the MSH6 nonsense c.2931C>G, p.Tyr977X mutation is similar in tumour spectra, age of onset and cumulative risk. These MSH6 families, despite their late age of onset, have a high lifetime risk of all Lynch syndrome-related cancers, significantly higher in women (89% by age 80) than in men (69%). The gender differences are in part explained by high endometrial (70%) and ovarian (33%) cancer risks added upon the high colorectal cancer risk (60%). The several occurrences of breast cancer are not due to the MSH6 mutations. These findings are of great importance for counselling, management and surveillance of families with MSH6 mutations.
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| 2. |
- Claesson, Jonas, et al.
(författare)
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Evaluation of intestinal preconditioning in a porcine model using classic ischemic preconditioning or lung recruitment maneuvers.
- 2008
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Ingår i: Shock. - : Ovid Technologies (Wolters Kluwer Health). - 1073-2322 .- 1540-0514. ; 21:1, s. 98-103
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Tidskriftsartikel (refereegranskat)abstract
- To test the hypotheses that repeated brief intestinal ischemic insults would elicit an intestinal preconditioning response to a subsequent intestinal I/R injury and that a similar response would be elicited by repeated lung recruitment maneuvers (RMs). Randomized experimental controlled animal study. University hospital animal laboratory. Eighteen anesthetized pigs. Animals were randomized to one of three groups, with six animals in each group. Control group 75-min superior mesenteric artery (SMA) occlusion followed by 60-min reperfusion. Ischemic preconditioning group, three 5-min-long SMA occlusions preceding 75-min SMA occlusion and 60-min reperfusion. Recruitment maneuver (RM) group, three 2-min-long RMs preceding 75-min SMA occlusion and 60-min reperfusion. We measured systemic and mesenteric hemodynamic parameters, jejunal mucosal perfusion, net mesenteric lactate flux, jejunal tissue oxygen tension, and mesenteric oxygenation. Every 15 min, jejunal microdialysate samples were collected and analyzed for glucose, lactate, and glycerol. Jejunal tissue samples were collected postmortem. After occlusion of SMA, regional parameters in all groups indicated abolished perfusion and gradually increasing intraluminal microdialysate lactate and glycerol levels. At reperfusion, regional parameters indicated mesenteric hyperperfusion, whereas microdialysis markers of mucosal anaerobic metabolism and cell injury decreased, although not reaching baseline. Histological examination revealed severe mucosal injury in all groups. There were no significant differences between groups in the observed parameters. No protective preconditioning response could be observed when performing repeated brief intestinal ischemic insults or repeated lung RMs before an intestinal I/R injury.
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| 3. |
- Dahlin, Anna M, 1979-, et al.
(författare)
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Plasma vitamin B12 concentrations and the risk of colorectal cancer : a nested case-referent study
- 2008
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 32:2, s. 304-314
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Tidskriftsartikel (refereegranskat)abstract
- In this nested case-referent study, we related plasma concentrations of vitamin B12 to the risk of colorectal cancer, taking into consideration prediagnostic plasma folate and total homocysteine concentrations. Subjects were 226 cases and double matched referents from the population-based Northern Sweden Health and Disease Study. Follow-up times from recruitment to diagnosis ranged from 0.1 to 12.7 years, with a median of 4.2 years. Plasma vitamin B12 concentrations were inversely associated with the risk of rectal cancer: univariate odds ratio for the highest versus lowest quintile 0.34 (95% confidence interval (95% CI) 0.13-0.83), p(trend) = 0.004. Risk estimates were attenuated slightly but remained statistically significant after adjustment for body mass index, current smoking, recreational and occupational physical activity, alcohol intake and prediagnostic plasma folate and total homocysteine concentrations: OR 0.30 (95% CI 0.08-0.99), p(trend) = 0.025. The corresponding univariate and fully adjusted odds ratios for colon cancer were 1.25 (CI 0.66-2.36), p(trend) = 0.185 and 1.42 (CI 0.67-3.05), p(trend) = 0.113, respectively. The observed over-risk was attributable to left-sided colon cancer. Interaction analyses including vitamin B12, folate and homocysteine were in line with the results for vitamin B12 alone. In conclusion, these results suggest that increasing levels of plasma vitamin B12, alone or together with other factors involved in one-carbon metabolism, may reduce the risk of rectal cancer, whereas for colon cancer, the association appears to be less clear.
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| 4. |
- Eklöf, Vincy, et al.
(författare)
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The reduced folate carrier (RFC1) 80G>A and folate hydrolase 1 (FOLH1) 1561C>T polymorphisms and the risk of colorectal cancer : a nested case-referent study
- 2008
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Ingår i: Scandinavian Journal of Clinical and Laboratory Investigation. - : Informa UK Limited. - 0036-5513 .- 1502-7686. ; 68:5, s. 393-401
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Tidskriftsartikel (refereegranskat)abstract
- Objective. Polymorphisms in genes involved in folate uptake and metabolism may affect folate status and, thereby, the risk of cancer. In this nested case‐referent study, we related two such polymorphisms, reduced folate carrier (RFC1) 80G>A and folate hydrolase 1 (FOLH1) 1561C>T, to the risk of colorectal cancer, taking into account pre‐diagnostic plasma folate and total homocysteine concentrations and the MTHFR 677C>T polymorphism, which were analysed in a previous study.Material and methods. Subjects were 220 cases and 414 matched referents from the population‐based Northern Sweden Health and Disease Study.Results. The RFC1 80A‐allele was associated with reduced plasma folate and elevated plasma total homocysteine concentrations, but the result was statistically significant only for folate. In contrast, the FOLH1 1561T‐allele was associated with higher plasma folate and reduced plasma total homocysteine concentrations, and the result was statistically significant only for homocysteine. Neither polymorphism was related to the risk of colorectal cancer, either in univariate analysis or after adjusting for body mass index, current smoking, recreational and occupational physical activity and alcohol intake. Further adjustment for folate or homocysteine status or the MTHFR 677C>T polymorphism did not affect risk estimates. Subjects with the RFC1 80AA genotype in combination with low plasma folate concentrations or the MTHFR 677TT genotype had a reduced risk of colorectal cancer of borderline statistical significance.Conclusions. These findings suggest that although the RFC1 80G>A and FOLH1 1561C>T polymorphisms may influence folate status, they are not likely to have a major independent role in the development of colorectal cancer.Read More: http://informahealthcare.com/doi/abs/10.1080/00365510701805431
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| 7. |
- Försti, A, et al.
(författare)
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Polymorphisms in the genes of the urokinase plasminogen activation system in relation to colorectal cancer
- 2007
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Ingår i: Annals of Oncology. - : Oxford University Press. - 0923-7534 .- 1569-8041. ; 18:12, s. 1990-1994
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Tidskriftsartikel (refereegranskat)abstract
- Background: Extracellular matrix degradation, mediated by the urokinase plasminogen activation (uPA) system, is a critical step in tumor invasion and metastasis. High tumor levels of uPA and its inhibitor PAI-1 have been correlated with poor cancer prognosis. We examined four single nucleotide polymorphisms (SNPs) with a potential effect on expression of genes in the uPA system for their role in colorectal cancer susceptibility and prognosis.Patients and methods: We genotyped the SNPs in 308 Swedish incident colorectal cancer patients with up to 16 years of follow-up and in 585 age- and sex-matched controls. We evaluated the associations between genotypes and colorectal cancer and Dukes' stage. Survival probabilities were compared between different subgroups.Results: Patients with PAI-1 –675 5G/5G genotype had better survival than patients with 4G/4G or 4G/5G genotypes when they had Dukes' stage A or B tumors (P = 0.023 and P = 0.015, respectively). No statistically significant association was observed between the SNPs and the risk of colorectal cancer or Dukes' stage.Conclusions: Our results suggest a role for the PAI-1 genotype in colorectal cancer prognosis, but further studies are needed to evaluate the impact of our finding in the clinic.
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| 8. |
- Gao, Jingfang, 1966-
(författare)
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Molecular and Biological Characteristics of Stroma and Tumor Cells in Colorectal Cancer
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Carcinogenesis is a progressive process involving multiple genetic alterations in tumor cells and complex interactions in the tumor-host microenvironment. To better understand the contribution of molecular alterations in tumor cells and stromal variables to the development of colorectal cancer (CRC) and identify prognostic factors, in this study we examined the clinicopathological and biological significance of stromal variables, including particularly interesting new cysteine-histidine rich protein (PINCH), inflammatory infiltration, angiogenesis and lymphangiogenesis, as well as hRAD50/hMRE11/hNBS1 proteins and hRAD50 mutation in tumor cell in CRC.PINCH protein expression in the stroma was increased from normal mucosa to primary tumors and further to lymph node metastases. In particular, PINCH expression was most intense at the tumor invasive margin, which was related to low inflammatory infiltration and independently related to an unfavorable prognosis. Low inflammatory infiltration at the tumor invasive margin was related to advanced tumor stage, worse differentiation and microsatellite instability (MSI). Further, it was independently related to an unfavorable prognosis. Increased blood and lymphatic vessel density was observed in the primary tumors compared with the corresponding normal mucosa. However, neither angiogenesis nor lymphangiogenesis was associated with tumor stage and patients’ survival. Moreover, PINCH was present in a proportion of endothelial cells of the tumor vasculature, and PINCH expression in tumor-associated stroma was positively related to blood vessel density.In primary tumor cells of CRC, strong expression of hRAD50, hMRE11 or hNBS1 was related to microsatellite stability (MSS). A high percentage of hMRE11 expression was associated with less local recurrence and high apoptotic activity. Further, we observed that the expression of hRAD50, hMRE11 or hNBS1 among normal mucosa, primary tumors and metastases in MSS CRC differed from that in MSI CRC. In MSS CRC, the expression intensity of hRAD50, hMRE11 and hNBS1 was consistently increased with respect to normal mucosa, but there was no difference between the primary tumors and metastases. In the primary MSS tumors, the expression of individual or combination of hRAD50/hMRE11/hNBS1 was associated with a favorable prognosis in the same series of the CRCs. Moreover, strong/high hRAD50 in MSS primary tumors was related to earlier tumor stage, better differentiation and high inflammatory infiltration, whereas strong hNBS1 expression tended to be independently related to a favorable prognosis in MSS CRC with earlier tumor stage. However, in MSI CRC, there were neither differences in the expression of hRAD50/hMRE11/hNBS1 among normal mucosa, primary tumors and metastases, nor any association of the protein expressions with clinicopathological variables. On the other hand, frameshift mutations of (A)9 at coding region of hRAD50 were only found in MSI CRC.Our study indicates that 1) PINCH is likely a regulator of angiogenesis, and PINCH expression at the tumor invasive margin is an independent prognostic indicator in CRC. 2) Inflammatory infiltration at the tumor invasive margin is also an independent prognostic indicator in CRC. The lack of association between high inflammatory infiltration and MSI may help to explain the non-association of MSI with survival in CRC patients. 3) Angiogenesis and lymphangiogenesis occur in the early stage of CRC development, but do not associate with CRC progression and patients’ prognosis. 4) hRAD50/hMRE11/hNBS1 may act dependently and independently, playing different roles in MSS and MSI CRC development. In MSS CRC, the strong expression of the three proteins, associated with a favorable prognosis, may present the cellular response against tumor progression. Expression of hNBS1 may be a prognostic indicator for MSS CRC patients in the earlier tumor stage. In MSI CRC, the frameshift mutations at the coding region of hRAD50 may contribute to tumor development.
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| 9. |
- Hahn-Strömberg, Victoria, 1971-
(författare)
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Cell adhesion proteins in different invasive patterns of colon carcinomas : a morphometric and molecular genetic study
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Colorectal carcinoma is the second most common type of cancer in both men and women in Sweden. Cancer of the colon and rectum are often considered together and their ten year survival rate is approximately 50 – 60 % depending on sex and location. Different histopathological characteristics of such cancers, including the complexity of growth, are of importance for prognosis. This thesis has compared different morphometric methods in order to achieve a quantitative and objective measurement of the invasive front of colon carcinoma. Since the growth pattern is dependent on the cell adhesiveness of different proteins we studied the distribution and localization of E-cadherin, Beta-catenin, Claudin 1,2,7 and Occludin as well as screened the genes for mutations. We found a perturbed protein expression of E-cadherin, Beta-catenin, Claudin 1,2,7 and Occludin in tumor sections compared to normal mucosa, but no relation to tumor volume or growth pattern could be seen. The tumor volume was found to be correlated to the growth pattern but not responsible to the perturbed protein expression. In the mutation screening we found a SNP in exon 13 the E-cadherin gene in the tumor, as well as in exon 2 of Claudin 1 and exon 4 of Claudin 7 in both tumor and normal mucosa. No correlation between mutations and growth pattern or tumor volume was found. In conclusion, this thesis shows that the computer image analysis with estimation of fractal dimension and number of free tumor cell clusters is superior to the semi quantitative visual grading of tumor invasive complexity. The aberrant expression of cell adhesion proteins in the tumor compared to normal mucosa as well as polymorphisms in the cell adhesion genes CLDN1 and CLDN7 in both tumor and normal mucosa can suggest that these aberrations are important in the tumorigenesis of colon carcinoma.
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| 10. |
- Hart, Andrew R, et al.
(författare)
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Diet in the aetiology of ulcerative colitis: A European prospective cohort study
- 2008
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Ingår i: Digestion. - : S. Karger AG. - 1421-9867 .- 0012-2823. ; 77:1, s. 57-64
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Tidskriftsartikel (refereegranskat)abstract
- Background/Aims: The causes of ulcerative colitis are unknown, although it is plausible that dietary factors are involved. Case-control studies of diet and ulcerative colitis are subject to recall biases. The aim of this study was to examine the prospective relationship between the intake of nutrients and the development of ulcerative colitis in a cohort study. Methods: The study population was 260,686 men and women aged 20-80 years, participating in a large European prospective cohort study (EPIC). Participants were residents in the UK, Sweden, Denmark, Germany or Italy. Information on diet was supplied and the subjects were followed up for the development of ulcerative colitis. Each incident case was matched with four controls and dietary variables were divided into quartiles. Results: A total of 139 subjects with incident ulcerative colitis were identified. No dietary associations were detected, apart from a marginally significant positive association with an increasing percentage intake of energy from total polyunsaturated fatty acids (trend across quartiles OR = 1.19 (95% CI = 0.99-1.43) p = 0.07). Conclusions: No associations between ulcerative colitis and diet were detected, apart from a possible increased risk with a higher total polyunsaturated fatty acid intake. A biological mechanism exists in that polyunsaturated fatty acids are metabolised to pro-inflammatory mediators.
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