Microsatellite instability and the association with plasma homocysteine and thymidylate synthase in colorectal cancer.

The possible associations between microsatellite instability, homocysteine and thymidylate synthase were investigated in tumors and plasma from 130 patients with colorectal cancer. Other analyses included thymidylate synthase and 5,10-methylene-tetrahydrofolate reductase gene polymorphisms, carcinoembryonic antigen, vitamin B12, and folate. Microsatellite instability of tumors was associated with higher levels of plasma homocysteine (p = 0.008) and higher protein expression of thymidylate synthase (p < 0.001). Supplemental analyses ruled out that the finding could be explained by the other analyzed factors. CEA was not associated with neither homocysteine nor microsatellite instability. The data suggests that there is a more pronounced methyl unit deficiency in microsatellite instable tumors.

DPD is a molecular determinant of capecitabine efficacy in colorectal cancer.

Capecitabine is a fluoropyrimidine-based drug that offers physicians a more convenient treatment for advanced colorectal cancer (CRC), with manageable toxicity and antitumor activity comparable to that of continuous-infusion therapies with 5-fluorouracil (5-FU). However, there are no validated and established predictive factors for clinical outcome of capecitabine efficacy in CRC. The gene expressions of the pyrimidine metabolism enzymes dihydropyrimidine dehydrogenase (DPD), thymidine phosphorylase (TP) and thymidylate synthase (TS) have previously been shown to be response determinants of fluoropyrimidine-based drugs in various tumors. Therefore, we investigated whether intratumoral mRNA expression levels of these genes are also associated with the clinical outcome of patients with metastatic CRC treated with first-line capecitabine. Thirty-seven patients with metastatic CRC were enrolled in this study and treated with single agent capecitabine. The intratumoral mRNA levels of DPD, TP and TS were assessed from paraffin-embedded tissue samples using laser-capture-microdissection methods and quantitative real-time PCR. There were 20 women and 17 men with a median age of 61 years (range 49-74). The median progression-free survival was 6.7 months (95% CI, 4.8-11.6 months), with a median follow-up of 14.4 months (range 1.3-18.7 months). Complete response was observed in 1 (3%), partial response in 6 (20%), stable disease in 14 (47%) and progressive disease in 9 (30%) patients (response was inevaluable in 7 patients). Higher gene expression levels of DPD were associated with resistance to capecitabine (P=0.032; Kruskal-Wallis test). Patients with a lower mRNA amount of DPD (

Impact of enteral supplements enriched with omega-3 fatty acids and/or omega-6 fatty acids, arginine and ribonucleic acid compounds on leptin levels and nutritional status in active Crohn's disease treated with prednisolone.

BACKGROUND: Patients with Crohn's disease (CD) often develop malnutrition due to disease activity. We aimed to assess the effect of two different enteral supplements of Impact(R) Powder (IP; Novartis, Switzerland) on leptin levels and nutritional status in active CD patients during prednisolone treatment and tapering. METHODS: Thirty-one CD patients were randomized to IP Extra (group 1) or IP Standard (group 2). Leptin levels, nutritional, clinical and biochemical markers were studied at inclusion, after 5 and after 9 weeks of the study. RESULTS: Leptin levels, body mass index (BMI) and total cholesterol increased significantly within both groups at week 5 compared to inclusion. Leptin levels correlated with BMI in both groups at inclusion and in group 2 at week 9. In group 1, triglyceride levels remained unchanged, while levels in group 2 increased significantly at week 5 compared to inclusion. Clinical and biochemical markers improved during the study compared to inclusion. CONCLUSIONS: Increased leptin levels during the study progress were transient, decreasing due to prednisolone withdrawal at the end of the study. Both formulas used as adjuvant therapy to prednisolone treatment were able to improve nutritional status in CD patients.

Thymidylate synthase and methylenetetrahydrofolate reductase gene polymorphism in normal tissue as predictors of fluorouracil sensitivity.

PURPOSE: To analyze thymidylate synthase (TS) and methylenetetrahydrofolate reductase (MTHFR) gene polymorphism with respect to fluorouracil (FU) sensitivity. PATIENTS AND METHODS: The study included a retrospective analysis of 88 patients with metastatic colorectal cancer and a prospective trial with 51 patients also with measurable metastases. All patients were treated with FU and leucovorin. The analysis of gene polymorphism was performed on normal intestinal tissue and lymphocytes. RESULTS: The response rate was significantly higher in patients with TS 3R/3R or MTHFR 677 TT gene polymorphism compared with the other groups. The difference of response rate translated to a difference in time to progression. Similar results were observed in the retrospective analysis and the prospective confirmatory trial. CONCLUSION: The analysis of gene polymorphism allows delineation of a group of patients (30%) with a response rate to a single drug of approximately 50%. This information should be used in the design of tailored treatment.

Prediction of response to chemoradiation in rectal cancer by a gene polymorphism in the epidermal growth factor receptor promoter region.

PURPOSE: Epidermal growth factor receptor (EGFR) has been associated with radioresistance in solid tumors. Recently a polymorphism in the Sp1 recognition site of the EGFR promoter region was identified. The present study investigated the predictive value of this polymorphism for the outcome of chemoradiation in locally advanced rectal cancer. METHODS AND MATERIALS: The study included 77 patients with locally advanced T3 rectal tumors. Treatment consisted of preoperative radiation therapy at a total tumor dose of 65 Gy and concomitant chemotherapy with Uftoral. Blood samples from 63 patients were evaluated for Sp1 -216 G/T polymorphism by polymerase chain reaction analysis. Forty-eight primary tumor biopsies were available for EGFR immunostaining. Patients underwent surgery 8 weeks after treatment. Pathologic response evaluation was performed according to the tumor regression grade (TRG) system. RESULTS: Forty-nine percent had major response (TRG1-2) and 51% moderate response (TRG 3-4) to chemoradiation. The rates of major response were 34% (10/29) in GG homozygote patients compared with 65% (22/34) in patients with T containing variants (p=0.023). Fifty-eight percent of biopsies were positive for EGFR expression (28/48). The major response rates with regard to EGFR immunostaining were not significantly different. EGFR-positive tumors were found in 83% of the GG homozygote patients compared with 38% of patients with TT or GT variants (p=0.008). CONCLUSIONS: There was a significant correlation between EGFR Sp1 -216 G/T polymorphism and treatment response to chemoradiation in locally advanced rectal cancer. Further investigations of a second set of patient and other treatment schedules are warranted.

Epidermal growth factor receptor analyses in colorectal cancer: a comparison of methods.

EGFR immunohistochemistry (IHC) status is not a reliable predictive marker for response to EGFR-targeted therapies. The present study compares the EGFR status at DNA, RNA and protein level. Blood samples, corresponding normal colon and colorectal cancer tissue were collected from 199 colorectal cancer (CRC) patients. EGFR status was evaluated by FISH analysis, real-time RT-PCR, ELISA and IHC. A polymorphism in the EGFR promoter was evaluated by PCR analysis. The EGFR levels by different methods were mutually compared. Seventy-eight percent of primary tumours and corresponding lymph nodes had equivalent EGFR status (28/34). There was a tendency to higher median protein level (by ELISA) in IHC positive patients compared to IHC negative patients (p=0.086). The median EGFR gene expression level was significantly lower in tumours than in the normal colon with no difference according to IHC status. No tumours had increased gene copy number by FISH. EGFR Sp1-216 polymorphism analysis showed a tendency for different EGFR tumour protein levels and gene expression levels according to the different genotypes. The results show a poor correlation between EGFR status at DNA, RNA and protein level. The predictive value of a combination of methods needs further evaluation in the clinical setting.

Expression of thymidylate synthase in primary colorectal adenocarcinoma.

Thymidylate synthase (TS) is a key regulatory enzyme in the cellular pathway of de novo pyrimidine synthesis and a target enzyme for 5-fluorouracil (5-FU). Most clinical studies have shown that high levels of TS in tumors are associated with decreased sensitivity to 5-FU treatment. In this study TS expression was assessed at DNA, RNA, and protein levels. The study included 69 tumors from patients with primary colorectal adenocarcinoma. At the DNA level TS enhancer polymorphism was measured on whole blood by PCR. At the RNA level TS mRNA expression was measured on formalin-fixed paraffin-embedded tumor tissue and on fresh-frozen tumor tissue by real-time RT-PCR. Protein expression was assessed by IHC. Correlation was found between TS mRNA expression in fresh-frozen tumor tissue and formalin-fixed paraffin-embedded tissue (R=0.71). TS enhancer 3/3 had significantly higher protein levels as assessed by IHC than the TS enhancer 2/2 (P=0.02), although there was no statistically significant correlation between TS enhancer polymorphism and TS mRNA expression. An interesting observation not previously reported is that the predominant IHC reaction pattern in tumors from patients with the TS enhancer genotype 3/3 is different in tumors from patients with genotypes 2/2 and 2/3. The results indicate that clinical studies of the significance of TS with regard to 5-FU-based chemotherapy should be based on assessment of TS activity at DNA, RNA, and protein levels.

Lack of the type III epidermal growth factor receptor mutation in colorectal cancer.

BACKGROUND: Epidermal growth factor receptor (EGFR) analysis by traditional immunohistochemistry does not provide clinicians with a reliable tool for the selection of patients to EGFR-targeted treatment in colorectal cancer (CRC). Alternative methods and further understanding of the EGFR signaling network are being investigated and mutations in the EGFR gene have been identified. The type III epidermal growth factor receptor, a tumour-specific, ligand independent, constitutively activated form of EGFR, might contribute to the malignant phenotype in CRC and may be a potential target for anticancer therapy. The aim of the present study was to investigate the presence of EGFRvIII in CRC by PCR and protein analysis. MATERIALS AND METHODS: The study included 79 colorectal cancer patients for PCR analysis and 50 patients for protein analysis by Western blots, in two different laboratories. RESULTS: No type III mutations were detected in our material. CONCLUSION: The EGFRvIII mutations are rare in colorectal adenocarcinomas and overall probability does not appear to contribute to the malignant phenotype of this disease.

Serum trefoil factors in patients with inflammatory bowel disease.

BACKGROUND: Trefoil factors (TFF1-3) play a critical role in mucosal protection and repair in the gastrointestinal tract. The aims of the present study were to examine associations between serum TFF1-3 and clinical and biochemical markers reflecting disease activity and to examine changes in TFF1-3 in patients with inflammatory bowel disease (IBD) before and during high-dose prednisolone treatment and tapering. METHODS: Serum concentrations of TFF1-3 were quantified in 48 ulcerative colitis (UC) and 50 Crohn's disease (CD) patients with little or moderate activity. Additionally, serum TFF concentrations were determined in patients with severe activity in colon IBD (4 UC and 6 CD) before and during prednisolone treatment with 7 healthy subjects as controls. RESULTS: Median concentrations of TFF1, TFF2, and TFF3 were significantly increased in IBD patients compared with healthy controls (p < 0.01). TFF3 concentrations correlated with clinical and biochemical parameters of disease activity in UC patients. In addition, a trend towards reduction in TFF concentrations during treatment with prednisolone and concomitant clinical and biochemical remission was observed. CONCLUSIONS: The present data support the concept that trefoil peptides are upregulated and may play a role in IBD mucosal protection and repair. In UC patients, TFF3 levels were increased in active disease levels correlated with disease activity indices. Due to a large variation, serum TFFs are not a potential marker for disease activity.

Insulin-like growth factors (IGFs) and IGF binding proteins in active Crohn's disease treated with omega-3 or omega-6 fatty acids and corticosteroids.

OBJECTIVE: Catabolism and growth impairment are well-known complications of inflammatory bowel disease (IBD). This may be caused by the disease activity itself and/or the medical treatment, and both may lead to changes in the growth hormone (GH)/insulin-like growth factor I (IGF-I) axis. The aim of the present study was to examine the effects of enteral nutrition, Impact Powder, as adjuvant therapy to corticosteroid treatment on changes in the GH/IGF-I axis in patients with Crohn's disease (CD). MATERIAL AND METHODS: The patients were randomized to 3-IP (omega-3-fatty acid (FA), 3 g/day) or 6-IP (omega-6-FA, 9 g/day). Changes in total IGF-I (tIGF-I) and total IGF-II (tIGF-II), free IGF-I (fIGF-I), IGF binding proteins (IGFBP-1 and IGFBP-3), IGFBP-3 protease activity and insulin levels were examined in 31 patients with active CD (CDAI: 186-603) during treatment with prednisolone (40 mg for 1 week) and tapering the dose by 5 mg/week. Clinical and biochemical markers of inflammation were studied at day 0, and after 5 and 9 weeks. RESULTS: There were no differences at baseline between the two groups. During the treatment period, tIGF-I, fIGF-I and IGFBP-3 increased significantly in both groups compared to baseline (p<0.05) without differences between the groups. Insulin and IGFBP-1 showed no significant changes throughout the treatment period. CONCLUSIONS: There was no difference between 3-IP and 6-IP as adjuvant enteral nutrition on the GH/IGF-I axis. The changes observed in the GH/IGF-I axis are in line with previously published studies and may be explained by corticosteroid treatment; however, we cannot exclude an additional effect of omega3-/omega6 FA as adjuvant enteral nutrition.

Low S-adenosylmethionine concentrations found in patients with severe inflammatory bowel disease.

BACKGROUND: S-adenosylmethionine is a methyl donor in many cellular reactions including detoxification of constantly produced hydrogen sulphide in the colon. A reduced capacity to detoxify hydrogen sulphide may be implicated in the pathogenesis of inflammatory bowel disease. S-adenosylmethionine could be low if this assumption is correct. We compared S-adenosylmethionine concentrations in whole blood in patients with severe and moderate inflammatory bowel disease with healthy reference persons. METHODS: S-adenosylmethionine concentrations in whole blood were measured using high-pressure liquid chromatography. Patients with Crohn's disease (n=21), ulcerative colitis (n=7) and healthy age-matched reference persons (or controls) (n=17) were studied. RESULTS: S-adenosylmethionine concentrations were significantly decreased in patients with severe inflammatory bowel disease (mean 1.10 mg/l) as compared to patients with moderate Crohn's disease and ulcerative colitis (mean 1.83 mg/l) and reference persons (mean 1.84 mg/l). Statistically significant inverse correlations were found between S-adenosylmethionine concentration and activity index (p<0.01 and R2=0.86) as well as Crohn's disease activity index (p<0.01 and R2=0.50) scores. CONCLUSIONS: Low concentrations of S-adenosylmethionine were found in patients with severe inflammatory bowel disease. Future studies will show whether S-adenosylmethionine is a marker for disease activity and a possible tool for investigation of sulphur toxicity as a causative mechanism in inflammatory bowel disease.

Platelets and anticoagulant capacity in patients with inflammatory bowel disease.

Patients with inflammatory bowel disease (IBD) are susceptible to thromboembolic complications. Several mechanisms can be responsible, including abnormal regulation of coagulation activity, disturbances of fibrinolysis, inflammatory reactions and thrombocytosis. The aim of this study was to assess hemostatic alterations in these parameters during exacerbation of disease. We studied disease activity in 99 IBD patients receiving anti-inflammatory therapy, in relation to: procoagulant markers, i.e. prothrombin fragment F1 + 2 (F1 + 2), D-dimer and platelet count, anticoagulant markers, i.e. protein C, protein S and antithrombin, and a mediator of inflammation (IL-6). Coagulation activity and platelet count were increased during active disease in IBD patients compared with those in a state of remission. The IL-6 concentrations were positively correlated with disease activity and thrombocytosis in patients with ulcerative colitis, but no association with the anticoagulant capacity could be demonstrated except for a decrease in protein C during high disease activity.