Dariusz Bielicki

Overexpression of 5-lipoxygenase in sporadic colonic adenomas and a possible new aspect of colon carcinogenesis

PurposeWe aimed to study the intracellular expression of 5-lipoxygenase (5-LOX), the primary competitor with cyclooxygenase-2 in arachidonic acid metabolism, as inflammatory enzymes may be involved in blocking apoptosis and promoting cancer growth by changing arachidonic acid metabolism within cells. Our purpose was to investigate the possible connection between 5-LOX expression and colon carcinogenesis by characterizing 5-LOX expression in histologically different colonic adenomas, determining the relationship between high expression of 5-LOX and various conventional clinicopathological features of adenomas, and finally characterizing the histological localization of cells with 5-LOX overexpression.MethodsA total of 111 patients were examined and 120 histologically different colonic adenomas analyzed (including four cases of intramucosal adenocarcinoma in a polyp). Immunohistochemical staining with polyclonal anti-5-LOX antibodies was performed.ResultsThere was a significant correlation between high 5-LOX expression and patient age, increased polyp size, high grade of intraepithelial neoplasia, villous and tubulovillous adenoma, and histological epithelial localization.ConclusionsWe observed a strong positive correlation between 5-LOX overexpression and the appearance of typical high-risk factors for malignant transformation in adenomatous polyps. The results support the role of 5-LOX in early stages of colon carcinogenesis.

Polymorphism of GSTM1 gene in patients with colorectal cancer and colonic polyps.

The frequency of the GSTM1 gene in patients with nonpolyposis colorectal cancer (CRC) (n = 70) and in subjects with colonic polyps (n = 27) was evaluated and compared with healthy individuals (n = 145). Patients with CRC were divided into the three groups: patients coming from the families with hereditary nonpolyposis colorectal cancer (HNPCC) (n = 17); patients with a high risk of HNPCC who were referred to as suspected of HNPCC (n = 25); patients with sporadic colorectal cancer without clinical features of hereditary tumours (n = 28). A simple polymerase chain reaction (PCR) - based assay to identify GSTM1 nulled and positive (non-nulled) genotype was used. No significant differences in frequency of nulled individuals were observed in both patients with HNPCC and patients suspected of HNPCC as well as in subjects with colonic polyps. The most interesting observation was made in the group of patients with sporadic CRC. Twenty individuals (71.4 %) of the group were GSTM 1 deficient which was significantly different from the control population (p < 0.04). The above data indicate that the absence of the GSTM1 gene is associated with a greater risk of sporadic colorectal cancer. There is an increase in the overall risk of approximately 2.5 as compared with the control population.

Treatment of large colorectal neoplasms by endoscopic submucosal dissection: a European single-center study.

Objective Endoscopic submucosal dissection (ESD) has a high curative resection rate for gastrointestinal mucosal lesions, but is not used widely in Europe because of a high complication rate and a long learning curve. This study analyzed the ESD learning curve at a single European treatment center. Materials and methods ESD and hybrid-ESD (hESD) procedures were used to treat large colonic lesions that could not be resected in one piece by other endoscopic methods. Procedure duration and speed, and en-bloc, complete (R0) resection, and complication rates were analyzed. Results Fifty-three patients underwent ESD (37 pure ESD, 16 hESD), most with rectal lesions (n=34, 64.2%). The mean lesion diameter was 3.7±1.1 cm (range 2.0–7.0 cm), the median procedure duration was 70.0 min [interquartile range (IQR) 31.0–113.0 min], and the median treatment speed was 0.086 cm2/min (IQR 0.055–0.152). En-bloc and R0 resection rates were 86.5% (32/37) and 81.1% (30/37), respectively. Procedure speed increased significantly after about 25 cases (P=0.0313). The median hESD procedure treatment speed was 0.159 cm2/min (n=16, IQR 0.094–0.193), which was better than with classical ESD (P=0.04). The hESD en-bloc and R0 resection rates were comparable to those of classical ESD (P>0.05). The only complication was bleeding, 5.7% (3/53); no perforation occurred. Recurrence was detected during follow-up (median 30.0 months, IQR 12–48) in one patient (1.7%). Conclusion ESD is useful and safe for resection of large colorectal polyps, and procedure speed increased considerably after 25 procedures. hESD was faster than ESD, with a high therapeutic resection rate.

Prevalence of Cryptosporidium sp. In Patients with Colorectal Cancer

UNLABELLED Parasitic protozoans of the Cryptosporidium genus are intracellular intestinal parasites of mammals, causing cryptosporidiosis. Clinically, cryptosporidiosis manifests as chronic diarrhoea. Individuals with immune disorders, including those with neoplasms, are at risk of symptomatic invasion. THE AIM OF THE STUDY Was the evaluation of Cryptosporidium sp. prevalence in patients with diagnosed colorectal cancer. MATERIAL AND METHODS The studied group encompassed 87 patients with diagnosed colorectal cancer, undergoing surgery at the Department of General and Oncological Surgery, Pomeranian Medical University, in the years 2009-2010. Immunoenzymatic tests for Cryptosporidium sp. on faeces samples were performed with the use of commercial test kit, ProSpecT(®)Cryptosporidium Microplate Assay (Remel Inc). RESULTS The presence of Cryptosporidium sp. was found in 12.6% of studied patients with colorectal cancer. The performed statistical analysis did not reveal any correlation between Cryptosporidium sp. infection and gender, age, neoplasm advancement stage as per Astler-Coller scale, neoplasm differentiation grade, or neoplastic tumour localisation in relation to the splenic flexure. CONCLUSIONS There was found high prevalence of Cryptosporidium sp. in patients with colorectal cancer. It was comparable to the prevalence reported for patients with immune deficiency.

Thymidylate synthase expression and p21WAF1/p53 phenotype of colon cancers identify patients who may benefit from 5-fluorouracil based therapy

BackgroundStudies on the expression of thymidylate synthase (TS) in colorectal cancers (CRCs) have failed to provide unequivocal prognostic or predictive information. Here, we assessed the prognostic significance of TS expression in Astler-Coller stage B2 and C CRCs defined by a p21WAF1/p53 immunophenotype in patients subjected to 5-fluorouracil (5FU)-based adjuvant therapy.MethodsA cohort of 189 CRCs was asssessed for TS, p21WAF1 and p53 expression on tissue microarrays using immunohistochemistry, and associations with disease-free survival (DFS) and overall survival (OS) of the patients were assessed using univariate and multivariate analyses.ResultsTS expression led to the stratification of patients with colon cancer, but not rectal cancer, with immunophenotypes other than p21WAF1+/p53- (referred to as P&P) into subgroups characterized by a worse (P&P TS+) and a better (P&P TS-) DFS and OS, in univariate (P = 0.006 and P = 0.005, respectively) and multivariate (P = 0.0004 and P = 0.002, respectively) analyses. The p21WAF1+/p53- immunophenotype was associated with a favorable prognosis, irrespective of TS expression.ConclusionsThe strong association observed between the P&P TS+ immunophenotype and a worse DFS and OS suggests a predictive significance of TS expression for 5FU-based adjuvant therapy in patients with colon cancers exhibiting the P&P immunophenotype. In addition, our findings suggest that the appropriate target for assessment of TS expression as a prognostic/predictive marker is a subgroup of colon cancers with an immunophenotype other than p21WAF1+/p53-, and that only in this subgroup high TS expression is associated with an unfavorable DFS and OS. Therefore, we suggest that assessing TS expression in conjunction with p21WAF1/p53 immunophenotyping of colon cancers may improve the selection of patients suitable for 5FU-based adjuvant chemotherapy.

Increased PCNA/cyclin index correlates with severity of duodenitis defined by histological criteria

The proliferative activity of crypt epithelial cells was studied in 64 duodenal biopsies using immunohistochemistry and proliferating cell nuclear antigen (PCNA)/cyclin monoclonal antibodies in alcohol-fixed paraffin-embedded sections. A positive correlation between duodenitis as defined by histological criteria and increased mean percentage of PCNA positive crypt cell nuclei (PCNA index) was found. The mean PCNA index in normal mucosa was 11.8±2.7% (mean ± SD), in mild (grade 1) duodenitis 17.3±3.9%, in moderate (grade 2) 30.6±6.9%, and in severe (grade 3) duodenitis 41.1±8.5%. The inclusion of PCNA index, which is easily measured in paraffin-embedded sections, in the existing histopathological grading systems of duodenitis may improve their clinical relevance.

Liver Expression of Sulphotransferase 2A1 Enzyme Is Impaired in Patients with Primary Sclerosing Cholangitis: Lack of the Response to Enhanced Expression of PXR

Background/Aim. Sulphotransferase 2A1 (SULT2A1) exerts hepatoprotective effects. Transcription of SULT2A1 gene is induced by pregnane-X-receptor (PXR) and can be repressed by miR-378a-5p. We studied the PXR/SULT2A1 axis in chronic cholestatic conditions: primary sclerosing cholangitis (PSC) and primary biliary cirrhosis (PBC). Materials/Methods. Western-blot/PCRs for SULT2A1/PXR were performed in PSC (n = 11), PBC (n = 19), and control liver tissues (n = 19). PXR and SULT2A1 mRNA was analyzed in intestinal tissues from 22 PSC patients. Genomic DNA was isolated from blood of PSC patients (n = 120) and an equal number of healthy volunteers. Liver miRNA expression was evaluated using Affymetrix-Gene-Chip miRNA4.0. Results. Increased PXR protein was observed in both PSC and PBC compared to controls and was accompanied by a significant increase of SULT2A1 in PBC but not in PSC. Decreased expression of SULT2A1 mRNA was also seen in ileum of patients with PSC. Unlike PBC, miRNA analysis in PSC has shown a substantial increase in liver miR-378a-5p. Conclusions. PSC is characterized by disease-specific impairment of SULT2A1 expression following PXR activation, a phenomenon which is not noted in PBC, and may account for the impaired hepatoprotection in PSC. miRNA analysis suggests that SULT2A1 expression in PSC may be regulated by miR-378a-5p, connoting its pathogenic role.

Nuclear thymidylate synthase expression in sporadic colorectal cancer depends on the site of the tumor

Colorectal carcinoma (CRC) is a heterogeneous disease with specific epidemiological, pathological, molecular, and clinical characteristics that depend on the location of the tumor relative to the splenic flexure. Thymidylate synthase (TS) is a major target of 5-fluorouracil-based chemotherapy for CRC and high expression of this enzyme in tumor cells can influence the effect of therapy. We examined differences in TS protein expression in nuclei of tumor cells between CRCs located proximal and distal to the splenic flexure. Nuclear TS was detected by immunohistochemistry with a TS 106 monoclonal antibody on tissue microarrays constructed from 269 CRCs. The median histological score of nuclear TS expression of all proximal tumors was two times higher (p = 0.0003) and in men three times higher (p = 0.00023) than that found in distal tumors. In multivariate analysis which included age, sex, Astler–Coller stage, histological grade, and site, only proximal location of the tumor was identified as an independent factor associated with higher TS expression (odds ratio 2.46, 95% confidence interval = 1.29–4.70, p = 0.0062). These results demonstrate significant differences in nuclear TS expression between proximal and distal cancers and suggest the potential importance of the site of the tumor for proper stratification of patients for chemotherapy.

Expression of p21WAF1 in Astler–Coller stage B2 colorectal cancer is associated with survival benefit from 5FU-based adjuvant chemotherapy

In several, but not all, previous studies, positive p21WAF1 expression has been suggested as an indicator of a good prognosis in patients with stage III/IV colorectal cancer. However, it is not known whether the same is true for stage B2 patients. The purpose of this study is to assess the influence of p21WAF1 expression in tumor cells on disease-free survival (DFS) and overall survival (OS) of Astler–Coller stage B2 and C patients with colorectal cancer who underwent 5-fluorouracil-based adjuvant chemotherapy. Nuclear p21WAF1 was detected by immunohistochemistry in tissue microarrays from 275 colorectal cancers. The expression of p21WAF1 was associated with DFS (p = 0.025) and OS (p = 0.008) in the subgroup of stage B2 patients that was treated with adjuvant chemotherapy. In multivariate analysis, it remained the only independent prognostic parameter in relation to DFS and OS (p = 0.035 and p = 0.02, respectively). In the subgroup of 72 stage B2 patients with positive p21WAF1 expression but not in the subgroup of 61 stage B2 patients with negative p21WAF1 expression, adjuvant chemotherapy was associated with better DFS (85% 5-year survival versus 65% without chemotherapy, p = 0.03) and OS (96% versus 82%, p = 0.014). In the combined stage B2 and C group of patients treated with adjuvant chemotherapy, positive p21WAF1 expression was also associated with better DFS and OS (p = 0.03, p = 0.002, respectively). Expression of p21WAF1 in colorectal tumor cells identifies a subgroup of Astler–Coller stage B2 patients who could benefit significantly from 5FU-based chemotherapy and may improve the selection of patients for adjuvant chemotherapy.

NOD2/CARD15 mutations in Polish and Bosnian populations with and without Crohn's disease: prevalence and genotype-phenotype analysis

Data on prevalence and phenotypic consequences of nucleotide-binding oligomerisation domain 2/caspase recruitment domains 15 (NOD2/CARD15) variants in Crohns disease (CD) population in Poland and Bosnia and Herzegovina (B&H) are nonexistent. We aimed to determine the prevalence of NOD2/CARD15 mutations and their association with disease phenotype in Polish and Bosnian patients with CD and in healthy controls. We prospectively recruited 86 CD patients and 83 controls in Poland and 30 CD patients and 30 controls in B&H, 229 in total. We determined the prevalence of NOD2/CARD15 mutations and their association with the disease phenotype according to Montreal classification. Participants were genotyped for Leu1007fsinsC and Gly908Arg mutations. At least one CD-associated allele was found in 29/86 (33.7%) of Polish CD patients and in 9/83 (10.8%) of healthy controls (p<0.001). In both CD patients and controls in Bosnian sample, at least one NOD2 mutation was found in equal number of patients (3/30; 10%) with all of the NOD2 mutation positive CD patients being homozygous, while controls being heterozygous. In Polish sample, perianal disease was less frequent in CD patients with any NOD2 mutation (1/21; 4.8%) compared to those without (11/41; 26.8%; p=0.046). Higher percentage of patients with NOD2 mutations had history of CD related surgery when compared with those without mutations (66.7% vs. 43.3%; p=0.05). The risk for CD is increased in patients with NOD2 mutations (Poland) and especially in the presence of homozygous NOD2 mutations (Poland and Bosnia). The presence of variant NOD2 alleles is associated with increased need for surgery and reduced occurrence of perianal disease.