Human papillomavirus infections among Hungarian female sex workers.

The purpose of this study was to assess the human papillomavirus (HPV) prevalence in cervical, oropharyngeal and anal samples of the high-risk population of Hungarian female sex workers (FSWs). HPV testing of swab specimens from FSWs (n = 34) using polymerase chain reaction (PCR) methodology was performed. Results were compared with control group (n = 52) matched for age. Questionnaires were used to obtain data regarding participants' sexual behaviour. Data were analysed using SPSS. HPV DNA was detected in at least one location in a great majority of FSWs (82.4%), compared with 46.2% of the general female population (P < 0.05). Both the cervical and the anal samples of sex workers showed higher infection rates than those of controls (64.7% vs. 34.6% and 50.0% vs. 15.4%, respectively, P < 0.05). High-risk HPV prevalence was also significantly higher in sex workers (55.9% vs. 25.0%, P < 0.05). A significantly higher proportion of FSWs had a history of genital warts (26.5% vs. 3.8%, P < 0.05). The results suggest that condom use may not result in adequate protection from HPV infection. The high infection rates among FSWs should be viewed as a priority group for HPV and cervical cancer prevention programmes since they are sources of HPV infection for the general population.

Incomplete knowledge--unclarified roles in sex education: results of a national survey about human papillomavirus infections.

The purpose of this study was to evaluate the awareness of human papillomavirus (HPV) infections both in male and female adults in Hungary. A self-administered, anonymous questionnaire was completed by 785 college students and parents between January and May, 2009. The results were analysed by gender and age. Participants' knowledge about HPV and HPV-associated conditions was relatively incomplete. One-third of the respondents had never heard about HPV prior to the survey. Almost half of the respondents (42%) thought that the only sexual way of spreading HPV was vaginal intercourse, while the role of skin-to-skin contact was disregarded (6%). More than one-third of the participants (38%) believed that condoms give full protection from HPV infection. Encouragingly, the majority of respondents (64%) were open to further information about sexually transmitted diseases. The most trusted sources of information were health professionals. When talking about children, parents attributed the major role in delivering information about sexually transmitted diseases to schools. Primary prevention through carefully planned educational programmes may further raise the awareness about HPV-associated conditions, thus reducing the comparatively high mortality of cervical carcinoma in Hungary.

Chemopreventive effect of Panax ginseng.

Asian ginseng (Panax ginseng C. A. Meyer) has been used in Chinese medicine for two thousand years. The root of ginseng contains several saponins (ginsenosides) which are biologically active compounds. Individual ginsenosides suppress tumor cell growth, induce cell differentiation, regulate apoptosis and inhibit metastasis formation. The aim of this study was to evaluate its chemo-preventive effects in an animal test model, through its regulatory effects on apoptosis and the cell cycle.The expression of genes (Bcl-2, Bcl-x and Cyclin D1) which affect apoptosis were examined, in different organs of animals which had consumed a ginseng-containing diet in the presence of a known carcinogen (DMBA). The pattern of gene expression was determined by Q-RT-PCR. The increase of antiapoptotic gene expression after carcinogenic exposure was suppressed by consumption of ginseng which promoted apoptosis.The population is exposed to numerous physical and chemical insults in the modern environment and these include compounds which are known carcinogens. Research has shown that it is possible to interfere with the multi-step process of carcinogenesis through the use of compounds with chemo-preventive effects, such as the inhibition of the activation of antiapoptotic genes.These results support the efficacy of ginseng-containing diets and dietary supplements in the prevention of cancerous diseases.

The immunohistochemical aspects of protein Mena in cervical lesions.

UNLABELLED: The proteins Ena/VASP (Enabled/Vasodilator-Stimulated Phosphoprotein) family is involved in the regulation of actin cytoskeleton which activity is very important for physiological tissue formation but is sometimes implied in pathological processes. In this study, we analyzed the immunohistochemical expression of Mammalian Ena (Mena), which is a member of this family, in the cervical intraepithelial neoplasia (CIN) and also in the cervical squamous cell carcinomas. We analyzed 30 cases with CIN (1, 2 and 3), and 10 squamous carcinomas. We used the EnVision system by LabVision. The Mena antibody, izotype mouse IgA, clone 21, provided by BD Biosciences. RESULTS: We observed that Mena was not expressed in the normal cervical squamous epithelium but its expression was increased in parallel with the increasing grade of CIN, with up-regulation upon transition to CIN3 and further to invasive carcinoma. This is the first study in the literature about Mena expression in cervical lesions.

The expression of cytoskeleton regulatory protein Mena in colorectal lesions.

The actin regulatory proteins Ena/VASP (Enabled/Vasodilator stimulated phosphoprotein) family is involved in the control of cell motility and adhesion. They are important in the actin-dependent processes where dynamic actin reorganization it is necessary. The deregulation of actin cycle could have an important role in the cells' malignant transformation, tumor invasion or metastasis. Recently studies revealed that the human orthologue of murine Mena is modulated during the breast carcinogenesis. In our study, we tried to observe the immunohistochemical expression of mammalian Ena (Mena) in the colorectal polyps and carcinomas. We analyzed 10 adenomatous polyps (five with dysplasia) and 36 adenocarcinomas. We used the indirect immunoperoxidase staining. BD Biosciences have provided the Mena antibody. We observed that Mena was not expressed in the normal colorectal mucosa neither in polyps without dysplasia, but its expression was very high in polyps with high dysplasia. In colorectal carcinomas, Mena marked the tumoral cells in 80% of cases. In 25% of positive cases, the intensity was 3+, in 60% 2+ and in the other 15% 1+. The Mena intensity was higher in the microsatellite stable tumors (MSS) and was correlated with vascular invasion, with intensity of angiogenesis marked with CD31 and CD105 and with c-erbB-2 and p53 expression. This is the first study in the literature about Mena expression in colorectal lesions.

The separation of the granulocytes from different rat strains. A comparative study.

Different Percoll density gradients were used to purify granulocytes from Long-Evans, Fischer, Sprague-Dawley, and Fischer/Long-Evans hybrid rats. Three different discontinuous gradient types were developed which permitted the separation of polymorphonuclear leukocytes (PMNLs) from the peripheral blood of the different rat strains. Our purification techniques were compared to each other in terms of purity and yield. Purities of 97.7 +/- 0.6%, 97.0 +/- 1.1%, 96.4 +/- 1.2% and 96.7 +/- 1.1% were achieved for the granulocyte fractions of LE, F344, SD and FL/F1 rats, respectively. The superoxide production of the isolated cells was also investigated and it was established that the granulocytes could be activated by phorbol-12-myristate-13-acetate (PMA).

Comparative studies on genotoxic and carcinogenic effects of different cytostatic protocols. I. In vivo cytogenetic analyses in CBA mice.

In vivo rodent cytogenetics may provide an important basis for an animal model for the assessment of the carcinogenic potential of antitumor drugs in man. In this paper, genotoxic alterations (i.e. sister chromatid exchanges and micronuclei) caused by different cytostatic protocols in CBA/Ca mice are described. The strongest sister chromatid exchange inducing effects were shown by the ABVD (doxorubicin-dacarbazine-bleomycinvinblastine) group and combinations containing cyclophosphamide. Compounds which affect the mitotic spindle induced only micronuclei, but not sister chromatid exchanges.

Investigation of c-myc oncogene amplification in colorectal cancer.

Tumour DNA samples of 20 patients with colorectal carcinoma were tested for c-myc amplification, using a quantitative dot-blot hybridization. Statistical analysis involving clinical and histological parameters like degree of differentiation, Dukes' stage, TNM staging system, age, sex and severity of disease, was applied to estimate the prognostic value of c-myc amplification. The amplification of the investigated oncogene--1.61-fold on the average--was found to significantly correlate with the presence of distant metastasis (corr. coeff.: 0.506, P < 0.05) and the severe course of the disease (corr. coeff.: 0.468, P < 0.05). This result supports the hypothesis that tumour cells with c-myc amplification represent a more malignant and aggressive phenotype. It is also worth noting that both c-myc amplification and formation of distant metastasis are late events in the progression of colorectal cancer, which accounts for the more severe course of the disease.

Studies on acute myelomonocytic leukemia in LBF1 rats.

Granulocytic leukemia was induced in Long-Evans (LE) rats by using the Huggins and Sugiyama method. After serial passage the cells became transformed. The newly transformed cells could be transplanted to LBF1 hybrid rats and observed more readily. A quantity of 10(8) cells/100 g body weight was injected intravenously and after 2-3 weeks myelomonocytic leukemia developed. By examining the bone marrow, spleen and lymph nodes, cytochemical tests verified this transformation. Transplanting 10(2)-10(4) cells under the renal capsule, a quickly growing solid tumor was observed, which caused metastasis to the parathymical lymph nodes and peritoneum. The investigation of oncogene expression for the myc and ras families revealed the presence of myc p62 and ras p21 oncoproteins in the tumor cells by using monoclonal antibodies in immunohistochemical tests. LBF1 rats proved to be good models in obtaining solid tumor growth and myelomonocytic leukemias, equivalent to human M4-M5 type leukemia.

Investigation of c-myc and K-ras amplification in renal clear cell adenocarcinoma.

Tumour DNA samples isolated from 36 patients with renal clear cell carcinoma were investigated for c-myc and K-ras amplification, using a quantitative dot-blot hybridization. The characteristic clinical and histological parameters involved in the statistical analysis were age, sex, histological grade of the tumour, the TNM staging system, tumour size and weight, vascular invasion and the quality of life. The goal of the study was to estimate the prevalence as well as the prognostic value of the amplification of the oncogenes in question. Amplified c-myc (2.47-fold on the average) was found in three specimens (8.3%), showing slight correlation with intravasation (P > 0.05, n.s.). K-ras amplification (2.93-fold) detected in six tumours (16.6%) was shown to significantly correlate with both histological grade (2.2 vs. 1.8, P < 0.05) and tumour size (15 vs. 8 cm, P < 0.05). In cases with amplified K-ras also lymph node involvement was somewhat more frequent (P > 0.05, n.s.). No coamplification of these oncogenes was observed. The results of the study suggest that K-ras amplification may account for a more rapid progression of the disease.

Allelic polymorphism of GSTM1 and NAT2 genes modifies dietary-induced DNA damage in colorectal mucosa.

Typically, cancer is caused by the interaction of genetic and environmental factors. In colorectal carcinogenesis, diet and nutritional habits are the most important external risk determinants. Allelic polymorphisms of certain metabolizing enzymes may have an influence on cancer risk by modifying the concentration of active carcinogenic compounds in the body. In the present study we investigated the interaction between nutritional and genetic susceptibility factors in human colon carcinogenesis. Healthy volunteers were divided into four groups, based on allelic polymorphisms of N-acetyltransferase 2 and glutathione-S-transferase M1 enzymes. Comet assay was used to determine the level of DNA strand breaks in exfoliated colorectal mucosal cells, following a 2-day vegetarian diet, and after switching to a 2-day 'high-meat' diet. The 'high-meat' diet statistically significantly increased the amount of single-strand breaks in rapid acetylators and among individuals with a GSMT1 + genotype, while it caused only a slight and not significant increase in the other groups. Our study emphasizes the importance of using susceptibility markers in cancer epidemiology, since environmental effects are strongly modified by these genetic factors.

The usefulness of in vivo gene expression investigations from peripheral white blood cells: a preliminary study.

Alterations of onco/tumour suppressor genes are involved in the formation of human hematological malignancies. Previously, in animal models, we demonstrated the applicability of in vivo gene expression investigations to monitor the effects of certain carcinogenic chemicals. In our present study we determined the expression of onco/suppressor genes from isolated peripheral white blood cells of patients with chronic myeloid leukaemia (CLL) and non-Hodgkin lymphoma (NHL). Gene expressions were determined by isolation of total RNA and slot blot hybridization with chemiluminescently labeled gene probes (Ha-ras, c-myc and p53) Expression levels were compared before and after treatment with a combined cytostatic protocol, containing cyclophosphamide, doxorubicin, vincristine and prednisolone (CHOP). Both the CLL and NHL group of patients exhibited significantly higher expression of the investigated genes than healthy controls. One month after the cytostatic treatment, we found considerably fewer individuals with overexpressed oncogenes than before the treatment. Our study proved that onco/tumour suppressor gene expressions could be used as biomarkers of certain hematological malignancies, and to monitor the therapeutical effect of cytostatic drugs.

Comparison of early onco/suppressor gene expressions in peripheral leukocytes and potential target organs of rats exposed to the carcinogen 1-nitropyrene.

An in-vivo model has been developed to study early expressions of c-myc, Ha-ras oncogenes and p53 suppressor gene as biomarkers of carcinogenic exposure and/or tumorigenesis. In order to validate the in-vivo expression changes as biomarkers, rats were treated with the outdoor air pollutant carcinogen 1-nitropyrene. The gene expression levels were measured after 24 and 48 h in potential target tissues (lung, liver, lymph nodes, kidneys, spleen) and in peripheral blood leukocytes. Another main objective was to prove the applicability of leukocytes as a surrogate tissue, having a similar expression pattern of the selected genes upon carcinogenic exposure. The c-myc oncogene was not suitable as an early biomarker because of the lack or low level of its expression. However, in the case of the other oncogene Ha-ras and the suppressor gene p53, remarkable and early changes were detected in the expression signals. Similar expression patterns could only be detected in leukocytes and the spleen; therefore we continue this validation study by using other types and routes of exposure.

In vivo effects of cyclophosphamide on oncogene and suppressor gene expression in a "follow up" study.

Cyclophosphamide is a chemotherapeutical drug, with proved carcinogenic side effects. Our previous experiments showed its effect on the expression of certain oncogenes and tumor suppressor genes. In order to further explore the effects of cyclophosphamide at the gene level an in vivo mouse model was developed. We compared the effects of cyclophosphamide with that of cyclosporine, which is a non genotoxic human carcinogenic chemical. After different time periods of intraperitoneal cyclophosphamide or cyclosporine injection, RNA was isolated from whole organs of experimental animals, and expression of onco/suppressor genes was determined by slot blot hybridisation. In our model we have proved that gene expression changes caused by cyclophosphamide can be detected even six months after treatment without tumor development. Our results support the hypothesis that gene expression investigations could be useful biomarkers in monitoring the effects of environmental carcinogenic compounds.

Short-term effects of 1-nitropyrene on chromosomes and on oncogene/tumor suppressor gene expression in vivo.

In order to establish an animal model testing the effects of 1-nitropyrene in vivo at the oncogene level, we investigated the early biological effects of 1-nitropyrene in mice. The treatment of 6-8 week-old CBA/Ca mice with a single 30 mumol/kg body weight dose of 1-nitropyrene caused a significant increase in chromosome aberrations 48 hours after exposure. The aberrations were mainly of the euploid type. We also found elevated expression of the Ha-ras oncogene in the isolated total cellular RNA from the liver, lung, kidney, spleen and thymus. The highest increase was seen in the lung and it was also high in the spleen and in the thymus. There was a higher increase in the males than in the females in all organs. In this study we confirmed that early genetic alterations such as oncogene expression, can be examined not only in vitro, but also in vivo experiments.

Different H2 haplotypes have a strong influence on oncogene action.

The H2 complex has an important role in determining susceptibility to viral and chemical leukemogenesis in inbred mice. This also applies to transplantable leukemias, within the syngeneic system. In this respect H2K is sensitive, H2d is relatively sensitive, and H2b is absolutely resistant to leukemia induction and transplantation. In our present study we investigated the effect of Cyclophosphamide, (a known chemical leukemogen) on onco/suppressor gene expression in CBA/Ca mice, very shortly after treatment with chemical carcinogen without any manifestation of tumour/leukemia symptoms. Here we describe, in a "short-term" experiment, the gene expression of Ha-ras, c-myc and p53 which was similar to the leukemia induction in a "long-term" experiment. H2K showed marked elevation in terms of onco/suppressor gene expression. H2b expression was modest and H2d turned out to be more or less silent. The results obtained from a short term gene expression investigation shows similarity to those obtained earlier from long term leukemia inducing experiments.

Effect of E-2-(4'-methoxybenzylidene)-1-benzosuberone on the 7,12-dimethylbenz[alpha]anthracene-induced onco/suppressor gene action in vivo. I: A 24-hour experiment.

The cyclic chalcone analogue, E-2-(4'-methoxybenzylidene)-1-benzosuberone (MBB), was found to show outstanding in vitro antineoplastic activity against P388, L1210, Molt 4/C8 and CEM cells as well as against a panel of human tumor cell lines. In order to determine whether this promising antineoplastic activity would extend to anticarcinogenic properties, the effects of MBB on the 7,12-dimethylbenz[alpha] anthracene (DMBA)-induced expression of c-myc, Ha-ras and p53 genes in isolated RNA from liver, lung, kidney, spleen, thymus, lymph nodes and bone marrow of CBA/Ca inbred mice was investigated. DMBA is a well-known chemical carcinogen, which can act as an initiator by causing point mutations in certain oncogenes and tumor suppressor genes. Elevated expression of oncogenes after treatment with DMBA and other carcinogenic chemicals has been noted previously. Administration of MBB simultaneously with DMBA, 24 hours prior to or 24 hours after the DMBA treatment characteristically modified the DMBA-induced expression of the three genes in the 24-hour experiments. The most pronounced suppression effect of MBB could be observed in almost all the investigated tissues when it was administered simultaneously with DMBA. These "short-term" in vivo results support our previous conclusion that MBB can serve as a model molecule for subsequent structural modifications in searching for new effective anticarcinogenic agents.

Effect of 7,12-dimethylbenz(a)anthracene on onco/suppressor gene action in vivo: a short-term experiment.

Dimethylbenz[a]anthracene is a pluripotent carcinogenic chemical, which acts as an initiator by causing point mutations in certain oncogenes and tumor suppressor genes. Changes in their expression may be another possible area of investigation the carcinogenic effect of DMBA. Elevated expression of oncogenes was previously has been shown after treatment with carcinogenic compounds. In the present study, expression of c-myc, c-Ha-ras and p53 24 hours after a single dose treatment of DMBA in the spleen and in the liver of Long-Evans rats was investigated. Control animals were injected with the solvent corn oil only. We could not find any significant change on the transcriptional level of the investigated oncogenes in the liver. In the spleen, the overexpression of Ha-ras was 2-fold and c-myc was 3-fold higher in the DMBA-treated rats than in the corresponding control group. Since DMBA is a typical environmental carcinogen, the results of animal experiments may serve as a basis for application of gene expression investigations as a screening method in humans.

Effect of ABVD therapeutic protocol on oncogene and tumor suppressor gene expression in CBA/Ca mice.

The in vivo investigation of onco/suppressor gene effects may provide new information on chemical-environmental carcinogenesis. We previously described the elevation of onco/suppressor gene expression due to CHOP and COPP chemotherapeutical protocols in a CBA/Ca mouse model. Below we describe the results of the onco/suppressor gene expression studies after treatment with ABVD, a non-cyclophosphamide containing protocol. Expression of c-myc, Ha-ras, and p53 genes was investigated 1/2, 1, 3, 6, 12, 24 hours, 2 6 30 days, 6, and 12 months after treatment with a single dose of ABVD protocol. RNA was isolated from the thymus, spleen, liver, bone marrow, kidneys, and hybridzed with chemiluminescently labelled probes of Ha-ras, c-myc, and p53 genes. Significant changes of gene expression was found in the spleen and thymus, even after 30 minutes. The female spleen seemed to be more sensitive than the male one, but no sex difference was observed in the thymus. No significant alteration was detected in the other investigated organs.

Changes in expression of onco- and suppressor genes in peripheral leukocytes--as potential biomarkers of chemical carcinogenesis.

An animal model was developed to investigate the expression of two oncogenes (c-myc, Ha-ras) and a suppressor gene (p53) as early markers of the effects of carcinogenic exposure and/or tumourigenesis. Inbred Long-Evans rats were treated with 7,12-dimethylbenz(a)anthracene and the transient/permanent gene expressions were measured after 24 and 48 hours by dot blotting in potential target tissues (lung, liver, lymph nodes, kidneys, spleen) and in peripheral blood leukocytes. The aim of the study was to test blood leukocytes, as surrogate tissue, showed similar expression patterns of the selected genes following carcinogenic exposure. c-myc did not prove to be an applicable early biomarker due to the lack of or low level of its expression. However, remarkable of early elevations were detected in the expression signals of Ha-ras and p53.