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- Monstein, Hans-Jürg, et al.
(författare)
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K-ras and B-raf gene mutations are not associated with gastrin- and CCK2-receptor mRNA expression in human colorectal tumour tissues
- 2004
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Ingår i: European Journal of Clinical Investigation. - : Wiley. - 0014-2972 .- 1365-2362. ; 34:2, s. 100-106
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Tidskriftsartikel (refereegranskat)abstract
- Background: Colorectal cancer is a multistep process caused by genetic alterations in cell growth regulatory genes such as K-ras and B-raf. It has been assumed that mutations in the K-ras gene induce gastrin gene expression and that gastrin stimulates the growth of colorectal cancer in an autocrine fashion by coexpressing gastrin and cholecystokinin (CCK)2 receptors. The aim of this study was to examine a possible association of K-ras and B-raf gene mutations with gastrin and CCK2 receptor mRNA expression in human colon and rectum tumour biopsy specimens. Methods: K-ras and B-raf gene mutations as well as gastrin and CCK2 receptor mRNA expression in 50 colon and 46 rectum biopsies, respectively, were determined using molecular biology methods. Results: K-ras mutations occurred in 44% colon and 30% rectum and B-raf mutations in 16% colon and 4% rectum tumours, respectively. Gastrin mRNA was expressed in 64% colon and 61% rectum tumours, whereas CCK2 receptor mRNAs was expressed in 32% colon and 13% rectum tumours. K-ras or B-raf gene mutations and simultaneous gastrin mRNA expression was observed in 40% colon and 17% rectum tumours, respectively. Coexpression of gastrin and CCK2 receptor mRNA occurred in 20% colon and 9% rectal tumours. Conclusions: The results do not support the hypothesis that K-ras and B-raf gene mutations have an impact on gastrin- and CCK-receptor mRNA expression in colorectal tumour tissues.
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- Österström, Anna, et al.
(författare)
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Expression of cytosolic and group X secretory phospholipase A2 genes in human colorectal adenocarcinomas
- 2002
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Ingår i: Cancer Letters. - 0304-3835 .- 1872-7980. ; 182:2, s. 175-182
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Tidskriftsartikel (refereegranskat)abstract
- Gene expression of cytosolic phospholipase A2 (cPLA2) and protein level of secretory PLA2 group X (sPLA2-X) are upregulated in human colorectal cancer and provide cyclooxygenase-2 (COX-2) with arachidonic acid, resulting in increased levels of PGE2. Mutated ras-genes are suggested to be involved in the regulatory pathway of cPLA2 in lung cancer cells. We analysed the gene expression of cPLA2 and sPLA2-X in 42 and 38 primary colorectal tumours, respectively, with and without K-ras mutations. We found an up-regulation of cPLA2 mRNA but the induction in tumour tissues does not correlate with Ras-gene mutations. Moreover, our results cannot consistently reflect an overexpression of sPLA2-X gene in colorectal cancer tissues.
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