The study of bacteria in biopsies from Slovak colorectal adenoma and carcinoma patients.

The development of colorectal cancer is affected by many factors, especially the intestinal microbiota. However, precise knowledge of bacterial communities associated with the mucosa in various parts of the colon is limited. Herein, we applied the gentamicin protection assay and detected the presence of intracellular bacteria in colorectal biopsies from Slovak patients with colorectal adenoma and carcinoma, and we compared this with healthy controls. The ENTEROtest 24 and MALDI-TOF mass spectrometry identified the cultivated bacteria and results revealed the presence of intracellularly localized Escherichia coli, Proteus mirabilis and Proteus vulgaris in patients with colorectal adenomas and carcinomas. In addition to these species, Klebsiella pneumoniae, Pseudomonas aeruginosa, Enterococcus faecalis and Bacillus cereus were identified in colorectal biopsies, but these were extracellular. The marked increase in relative abundance of intracellular E. coli in patients with colorectal adenomas and carcinomas was statistically significant compared to controls, and our preliminary data supports E. coli's role as a pro-oncogenic pathogen.

Prevalence of serological response to Borrelia burgdorferi in farmers from eastern and central Poland.

Lyme borreliosis (Lyme disease) caused by the Borrelia burgdorferi sensu lato spirochete is the most common tick-borne infection manifested by a wide spectrum of clinical symptoms. In Poland, the preventive health care does not comprise individual farmers as it is practiced in foresters. The objective of this study was to evaluate the exposure of Polish farmers to infection with B. burgdorferi, based on serological screening test and epidemiological investigation. A total of 3,597 farmers were examined for the presence of B. burgdorferi antibodies, as well as interviewed regarding exposure to ticks and prophylaxis of tick-borne diseases. The prevalence varied between 18.2 and 50.7 % suggesting a focal occurrence of borreliosis. A significant increase in the frequency of positive reactions in the oldest age ranges was observed, equaling 30.9 % in the range of 60-69 years and 53.6 % in the range of 80-91 years. The prevalence of the anti-B. burgdorferi antibodies of IgG class (14.7 %) was similar to that of IgM class (16.0 %). Seroreactivity to B. burgdorferi antigen was significantly higher in the group of farmers exposed to repeated tick bites. Significant relationships were also found between some other risk factors and occurrence of seropositive reactions to B. burgdorferi. To the best of our knowledge, this is the first study concerning seroprevalence to B. burgdorferi carried out on such a large group of farmers. Results indicate a high risk of B. burgdorferi infection among Polish farmers and associations between some risk factors and the presence of seropositive reactions.

Novel strategies for comprehensive mutation screening of the APC gene.

Colorectal cancer is the 4th most common cause of cancer related deaths worldwide and new possibilities in accurate diagnosis and targeted treatment are highly required. Mutations in adenomatous polyposis coli (APC) gene play a pivotal role in adenoma-carcinoma pathway of colorectal tumorigenesis. The quarter century from its´ first cloning, APC became one of the most frequently mutated, known driver genes in colorectal cancer. Intensive routine molecular testing of APC has brought the benefits for patients with family history of polyposis or colorectal cancer. Nevertheless, multiple mutational disease-causing mechanisms make the genetic testing still challenging. This minireview is focused on implementation of novel APC mutation screening diagnostic strategies for polyposis families according to the current findings. A further understanding and improved algorithms may help to increase the mutation detection rate. APC germline mutations achieve close to 100% penetrance, so more comprehensive approach followed by preventive and therapeutic strategies might reflect in decrease in burden of colorectal cancer.

Modification of microflora imbalance: future directions for prevention and treatment of colorectal cancer?

Increasing incidence and mortality of colorectal cancer brings the necessity to uncover new possibilities in the prevention, diagnosis and treatment. The microbiome as the collective genetic material of the microflora, overexceed the number of genes in the human genome and is unique for each individual. Due to the benefits providing for the host and mainly for immediate interaction with the host immune system, a gastrointestinal microflora can be considered "cardinal microbiome". Host-microbial relations includes symbiotic, pathogenic and competitive interactions. Causal role of gastrointestinal microflora in colorectal carcinogenesis is still not well determined. This minireview is focused on current evidence in understanding the role of bacteria in colorectal carcinogenesis, the impact of bacterial dysbiosis on tumor formation, and ability of probiotics and bacterial vectors to modulate the gastrointestinal microflora as prevention and therapy tool in colorectal cancer.

Intestinal flora of FAP patients containing APC-like sequences.

Colorectal cancer mortality is one of the most common cause of cancer-related mortality. A multiple risk factors are associated with colorectal cancer, including hereditary, enviromental and inflammatory syndromes affecting the gastrointestinal tract. Familial adenomatous polyposis (FAP) is characterized by the emergence of hundreds to thousands of colorectal adenomatous polyps and FAP syndrome is caused by mutations within the adenomatous polyposis coli (APC) tumor suppressor gene. We analyzed 21 rectal bacterial subclones isolated from FAP patient 41-1 with confirmed 5bp ACAAA deletion within codons 1060-1063 for the presence of APC-like sequences in longest exon 15. The studied section was defined by primers 15Efor-15Erev, what correlates with mutation cluster region (MCR) in which the 75% of all APC germline mutations were detected. More than 90% homology was showed by sequencing and subsequent software comparison. The expression of APC-like sequences was demostrated by Western blot analysis using monoclonal and polyclonal antibodies against APC protein. To study missing link between the DNA analysis (PCR, DNA sequencing) and protein expresion experiments (Western blotting) we analyzed bacterial transcripts containing the 15Efor-15Erev sequence of APC gene by reverse transcription-PCR, what indicated that an APC gene derived fragment may be produced. We observed 97-100 % homology after computer comparison of cDNA PCR products. Our results suggest that presence of APC-like sequences in intestinal/rectal bacteria is enrichment of bacterial genetic information in which horizontal gene transfer between humans and microflora play an important role.

Different phenotype manifestation of familial adenomatous polyposis in families with APC mutation at codon 1309.

Germline mutation in APC gene induced development of familial adenomatous polyposis (FAP). The risk of developing specific manifestation of FAP is often correlated with the position of the inherited APC mutation. Patients with mutations localized in the largest exon 15 between codons 1286 and 1513 (mutation cluster region, MCR) have generally a worse prognosis with early onset of the disease. We found 6 FAP families with mutation at codon 1309 (3927_3931delAAAGA) in the cohort of 39 FAP Slovak families with rapid cancer progress. In addition, mutation in codon 1309 was detected in three family members, one of them with a very different phenotype. This oldest family member, aged 81, has persisted asymptomatic without clinical manifestations.

Contribution of p53, p63, and p73 to the developmental diseases and cancer.

Tumor suppressor TP53 gene is one of the most mutated genes in human genome. Inactivating somatic mutations and disruption of p53 protein have been described in almost all human malignancies. Its inactivation by germline mutation leads to the rare but severe familial precancerosis termed Li-Fraumeni syndrome. This syndrome is characterized by the early onset of different types of cancers including soft-tissue sarcomas, breast and brain cancers, leukemias, lung, laryngeal cancers, and adrenocortical carcinomas. The key role of p53 in tumor suppression has been confirmed in animal models as well. The p53 -knock-out and knock-in animals were born alive but were tumor prone. In the late nineties, two genes with high homology with TP53 were discovered, TP73 and TP63, respectively. Animal models showed that p73 is an important player in neurogenesis, sensory pathways and homeostatic control. The p63 is critical for the development of stratified epithelial tissues such as epidermis, breast, and prostate. Despite the structural similarities with p53, the function of these proteins in tumorigenesis is controversial. On one hand, there are evidences that both, p63 and p73-deficient animals are not tumor prone; on the other hand, there is evidence that such animals develop tumors later during their life. Unlike in TP53 gene, mutations in TP63 and TP73 genes are rare, however, germline mutations in TP63 are linked to the human developmental diseases. In this minireview, we describe the contribution of the p53, p63, and p73 to human pathology with emphasis on their different roles in development and tumorigenesis.

Ashkenazi founder BRCA1/BRCA2 mutations in Slovak hereditary breast and/or ovarian cancer families.

Germline mutations in BRCA1 and BRCA2 have been predominantly associated with the breast and ovarian cancers. Two mutations in BRCA1 (185delAG and 5382insC) and one mutation in BRCA2 (6174delT) are common in Ashkenazi Jewish population. To determine the proportion of these founder mutations, we analyzed DNA samples of 120 Slovak hereditary breast and/or ovarian cancer (HBOC) suspected families. Two particular exons of BRCA1 (2, 20) and 11N segment of BRCA2 were screened by single strand conformation polymorphism (SSCP) followed by DNA sequencing of fragments showing abnormal migration pattern. Mutational analysis revealed that 7 out of 20 (35%) families with detected BRCA1/BRCA2 pathogenic alteration harbored one of three Jewish mutations: five families with 5382insC, one family with 185delAG and one family with 6174delT. Interestingly, we have noted a very rare phenotype, when 5382insC in BRCA1 co-segregated also with endometrial carcinoma. Similarly to the studies from other countries of Central and Eastern Europe, the most frequent pathogenic alteration found was 5382insC that accounted for 1/4 of all gene defects detected. Following the high proportion of Ashkenazi Jewish founder mutations in Slovak HBOC families, a pre-screening for at least 5382insC mutation in individuals at even moderate risk would be appropriate.

Prevention of febrile neutropenia in cancer patients by probiotic strain Enterococcus faecium M-74. Pilot study phase I.

Febrile neutropenia (FN) remains a potentially life-threatening complication of anticancer chemotherapy. Bacterial translocation via intestinal mucosa is a significant mechanism of FN development. Competitive inhibition of bowel colonization by pathogenic microorganisms by lactic acid bacteria could be a useful prevention of FN. The aim of the study was the evaluation of dose and safety of probiotic strain Enterococcus faecium M-74 enriched with organic selenium in patients with solid and hematological malignancies. Eleven (9 M/2F) patients were included in the study. In the first phase six patients with germ cell tumors treated by chemotherapy were included. They received prophylaxis by nonpathogenic strain E. faecium M-74 during 2 cycles of chemotherapy. The planned daily dose was 6 x 10(9) bacteria. Regarding the insufficient colonization of the gut, the dose was further increased up to 18 x 10(9) tid. After safety evaluation, five patients were included with relapse of acute leukemia. In patients with germ cell cancer, severe neutropenia G3/4 was noted in 10 of 12 cycles of chemotherapy. The febrile episode was not observed in any of the patients. The gut colonization by enterococci reaches 10(6) CFU/g stool. In 5 patients with acute leukemia during 127 days of severe neutropenia 12 febrile episodes occurred. There was not noted any febrile episode or infection provoked by the tested strain. Tolerance of therapy was excellent without significant undesirable effects. Optimal dose was assessed and safety of probiotic strain was evaluated in neutropenic patients with solid, or hematological malignancies. Based on these results we plan phase II study to evaluate the effectiveness of this strain in FN prophylaxis.

Intramucosal bacteria in colon cancer and their elimination by probiotic strain Enterococcus faecium M-74 with organic selenium.

Intraepithelial bacteria were isolated by the gentamicin protection assay (GPA) from biopsy samples obtained at colonoscopy (colon cancer, n = 10 patients; colonic adenoma, n = 20; control group, n = 20; cancer patients without gastrointestinal tract GIT malignancy, n = 10). After a three-month administration of E. faecium M-74 to patients with positive GPA biopsies, 172 biopsy specimens from 60 patients were examined with the GPA. The number of biopsies with intracellular bacteria was significantly higher in adenoma and carcinoma group than in control group (26 vs. 10%; p = 0.004); in cancer patients without GIT malignancy the difference was nonsignificant. E. faecium M-74 was also administered to 5 patients with colonic adenoma; according to a control colonoscopy the number of biopsies with intracellular bacteria was significantly lower after probiotic administration (48 vs. 16%; p = 0.03). A striking prevalence of intraepithelial bacteria was also showed in patients with large bowel adenoma and carcinoma. The administration of probiotic strain M-74 can thus be considered to be an effective and promising method for elimination of pathogenic bacteria in the case of inflammatory bowel disease and colon cancer.

Characterisation of X;17(q12;p13) translocation breakpoints in a female patient with hypomelanosis of Ito and choroid plexus papilloma.

An X;17 translocation breakpoint was characterised in a 5-year-old female with hypomelanosis of Ito (HI) who exhibits characteristic hypopigmented lesions, psychomotor retardation, and choroid plexus papilloma. A YAC clone containing the locus DXS1 from Xq12 was found by fluorescence in situ hybridisation to cross the translocation breakpoint. Cosmid clones positive for DXS1 were used to identify and clone the translocation junction fragment from the patient's DNA. A chromosome-17-specific DNA fragment was isolated and used to identify cosmid clones crossing the translocation from chromosome 17p13. Exon trapping identified two known genes from chromosome 17: FMR1L2 (the fragile X mental retardation syndrome like protein 2) and SHBG (human sex hormone-binding globulin). Mapping the FMR1L2 and SHBG genes showed that neither gene was disrupted by the translocation.

Diagnosis of bovine leukosis virus infection by solid phase radioimmunoassay for virus antibody.

Solid phase radioimmunoassay for detection of anti-BLV antibodies in sera of infected animals is described. Viral antigens bound to surface of polystyrene are able selectively adsorb the antibodies from serum. Detection of bound antibodies quantitatively was done by 125I-labeled protein A from Staphylococcus aureus. Technical details of the assay are reported. The assay could be used as competitive one as well. Two different methods for detection of anti-BLV antibodies were compared with solid phase RIA. The solid phase RIA is highly sensitive, specific and available for large-scale examination. The assay is recommended for early diagnosis of bovine leukosis.

Comparison of radioimmunoassay for internal protein of bovine leukemia virus with neutralization test employing VSV-BLV pseudotype.

Two methods for the detection of antibodies to the bovine leukemia virus (BLV) in infected animals were compared for their suitability for the early diagnosis of bovine leukemia - pseudotype neutralization test (PNT) employing vesicular stomatitis virus - bovine leukemia virus pseudotypes (VSV-BLV), and radioimmunoassay test (RIA) for major internal viral protein p24 of the BLV. The comparison was made using more than 300 sera from cows of the herds with high incidence of bovine leukemia. In infected animals the presence of antibodies against virus envelope glycoprotein detected by PNT and antibodies against major structural viral protein p24 detected by RIA were found always coincidentally. Both methods were found highly comparable and suitable for early detection of bovine leukemia virus infected animals.

Karyological and isoenzyme characterization of established human sarcoma cell lines.

Six established human sarcoma cell lines (giant cell tumor of bone B-5GT, fibrosarcoma, B-6FS, cystosarcoma phylloides B-19CS, synovial sarcoma U-4SS and two osteogenic sarcomas U-20S and U-393OS) have been studied and compared to the normal B-41FB fibroblastic cells and the HeLa cells. For cytogenetic and isoenzyme characterization both conventional and G banding techniques as well as the mobility of lactate dehydrogenase (LDH) and glucose-6-phosphate dehydrogenase (G-6-PD) were employed. All six sarcoma cell lines had karyotype and LDH patterns of human cells. A study of the chromosome counts distribution revealed a large variability from one sarcoma cell line to the other. There was no evidence of any cross-contamination between the lines or by HeLa cells. This conclusion is based on the detection of G-6-PD with B phenotype, the lack of HeLa marker chromosomes in all sarcoma lines and the presence of Y chromosome in U-4SS and U-393OS derived from male donors. In addition, each sarcoma cell line revealed a group of distinctive marker chromosomes which can serve to identify them and help to control cell line specificity during in vitro culturing.

Bovine leukemia provirus in the DNA of different infected host cells.

Bovine leukemia provirus is reported to be integrated in the DNA of different infected mammalian cells. We observed morphological transformation in BLV infected sheep fetal spleen, kidney, thymus and sternal cultures. The presence of BLV specific sequences in their genome was established after digestion with the restriction endonuclease EcoRI and hybridization with a BLV specific probe. Human myeloma ARH77 and myeloid K562 cells infected with BLV were virus productive as detected by a reverse transcriptase assay. The presence of proviral sequences was confirmed after Southern blotting analysis. Restriction digestion by SacI enzyme yielded a complete 8.9 kb BLV provirus in infected ARH77 cells and a smaller 7.5 kb BLV fragment in infected K562 cells.

Bovine leukosis virus: recloning of specific DNA fragments.

DNA fragments generated by Bam HI restriction endonuclease digestion of the provirus of bovine leukosis virus (BLV) was recloned in several plasmids. Recombinant plasmids containing X-region, env gene and a part of pol gene were prepared in pBR322, and in a plasmid containing promotor PR. Fragments env gene and a part of pol gene inserted were also into the pSV2-dhfr plasmid which has the both bacterial and eukaryotic promotors together with the gene for folic acid reductase. The expression possibility of these inserted BLV sequences either in mammalian cells after transfection or in bacteria is now tested.

The combination of heteroduplex analysis and protein truncation test for exact detection of the APC gene mutations.

Familial adenomatous polyposis (FAP) is usually associated with mutation in the adenomatous polyposis coli (APC) gene. To examine the occurrence of these mutations in the number of FAP suspected families from the whole Slovakia effectively, we have applied heteroduplex analysis (HDA) and protein truncation test (PTT) for the analyses of 2-5 base pair deletions and point mutations of the APC gene. In the analyzed exon 15 of the APC gene determined by the primers 15Efor-15Grev for HDA and 15ET7-15J3 for PTT more than 70% of mutations should be deletions [3, 12], which are detectable by HDA. In our collection of 5 FAP families mutations in the APC gene were found in families 10, 27 and 41 using HDA. By PTT test the formation of truncated APC protein in FAP families 2, 10, 16 and 27 were revealed. The necessity of combination of at least HDA and PTT techniques for exact detection of APC mutations in analyzed APC region is discussed.

The most frequent APC mutations among Slovak familial adenomatous polyposis patients. Adenomatous polyposis coli.

We screened 46 suspected families from whole Slovakia for familial adenomatous polyposis (FAP) cancer predisposition. Individuals were enrolled to the adenomatous polyposis coli (APC) gene mutations mapping program at the base of previous clinical investigation. We have used the following techniques: heteroduplex analysis (HDA), protein truncation test (PTT), single strand conformation polymorphism (SSCP) and sequencing for the identification and detailed positional analysis of APC mutations. Around 90% of all detected mutations were found being truncated. The most frequent mutations from this collection were located within codons 1309 and 1061 of exon 15 and represented 15% and 7%, respectively of all tested families. The expressive phenotype, large amount of colorectal polyps and congenital hypertrophy of the retinal pigment epithelium (CHRPE) were associated to all mutations within codons 1309 and 1060.

Transfection of BLV containing DNA into NIH 3T3 cells.

Cell DNA isolated from bovine leukosis virus (BLV) productive cell clones was transfected into the NIH3T3 cells. DNA from some cell clones was able to transform NIH3T3 cells. The transformed cells were cloned, and in 4 cell clones out of 33 bovine leukosis virus specific sequences were detected by hybridization with labeled BLV probe. According to the restriction analysis the BLV sequences were incomplete, they were rearranged, deleted, or both. The DNA from NIH3T3 transformants with BLV sequences was able to transform in the second round transfection experiments NIH3T3 cells again, but in these transformants BLV specific sequences were not detected. Cell DNA from sheep tumors induced by BLV was able to transform the NIH3T3 cells too, but BLV specific sequences were not present in the transformants. It appears that BLV specific sequences are not required for NIH3T3 cell transformation.

Characterization of APC exon 15 germ-line mutation in FAP family with severe phenotype showing extracolonic symptoms.

The adenomatous polyposis coli (APC) gene plays a crucial role in colorectal carcinogenesis. Germ-line mutations of APC gene give rise to familial adenomatous polyposis coli (FAP) - autosomal dominant syndrome manifesting hundreds to thousands of colorectal polyps, if untreated with malignant progression. We have used the techniques of heteroduplex analysis (HDA), protein truncation test (PTT), single strand conformation polymorphism (SSCP) and DNA sequencing for the identification and detailed positional analysis of mutations in IFAP family with the expressive phenotype characterized by polyposis and extracolonic lesions. Detailed analysis revealed a 5bp deletion in a mutation cluster region (MCR) in exon 15 of APC gene in codon 1308. Two screened members of the FAP family exhibited this novel mutation.