The non-vesicle cell-free DNA (cfDNA) induces cell transformation associated with horizontal DNA transfer.

BACKGROUND: Cell-free DNA (cfDNA) is a source for liquid biopsy used for cancer diagnosis, therapy selection, and disease monitoring due to its non-invasive nature and ease of extraction. However, cfDNA also participates in cancer development and progression by horizontal transfer. In humans, cfDNA circulates complexed with extracellular vesicles (EV) and macromolecular complexes such as nucleosomes, lipids, and serum proteins. The present study aimed to demonstrate whether cfDNA not associated with EV induces cell transformation and tumorigenesis. METHODS: Supernatant of the SW480 human colon cancer cell line was processed by ultracentrifugation to obtain a soluble fraction (SF) and a fraction associated with EV (EVF). Primary murine embryonic fibroblast cells (NIH3T3) underwent passive transfection with these fractions, and cell proliferation, cell cycle, apoptosis, cell transformation, and tumorigenic assays were performed. Next, cfDNA was analyzed by electronic microscopy, and horizontal transfer was assessed by human mutant KRAS in recipient cells via PCR and recipient cell internalization via fluorescence microscopy. RESULTS: The results showed that the SF but not the EVF of cfDNA induced proliferative and antiapoptotic effects, cell transformation, and tumorigenesis in nude mice, which were reduced by digestion with DNAse I and proteinase K. These effects were associated with horizontal DNA transfer and cfDNA internalization into recipient cells. CONCLUSIONS: The results suggest pro-tumorigenic effects of cfDNA in the SF that can be offset by enzyme treatment. Further exploration of the horizontal tumor progression phenomenon mediated by cfDNA is needed to determine whether its manipulation may play a role in cancer therapy.

Hereditary diffuse gastric cancer (HDGC). An overview.

It is estimated that up to 10% of gastric carcinomas show familial aggregation. In contrast, around 1-3 % (approximately 33,000 yearly) are genuinely hereditary. Hereditary diffuse gastric cancer (HDGC) is a rare malignancy characterized by autosomal dominant inheritance of pathological variants of the CDH1 and CTNNA1 genes encoding the adhesion molecules E-cadherin and α-catenin, respectively. The multifocal nature of the disease and the difficulty of visualizing precursor lesions by endoscopy underscore the need to be aware of this malignancy as surgical prevention can be fully protective. Here, we provide an overview of the main epidemiological, clinical, genetic, and pathological features of HDGC, as well as updated guidelines for its diagnosis, genetic testing, counseling, surveillance, and management. We conclude that HDGC is a rare, highly penetrant disease that is difficult to diagnose and manage, so it is necessary to correctly identify it to offer patients and their families' adequate management following the recommendations of the IGCL. A critical point is identifying a mutation in HDGC families to determine whether unaffected relatives are at risk for cancer.

Common variants in the chromosome 2p23 region containing the SLC30A3 (ZnT3) gene are associated with schizophrenia in female but not male individuals in a large collection of European samples.

Previously, we found a significant gender-specific association of schizophrenia, in a UK case/control study, with SLC30A3, a candidate that is consistently down-regulated in schizophrenia in two independent cohorts. In view of the potential significance of this finding, we extended this study to a larger cohort using GWAS data from the Psychiatric Genetic Consortium (PGC). Meta-analysis was performed for the only two SLC30A3 SNP variants (rs11126936 and rs11126929) available in most PGC cohorts. A significant association with schizophrenia was found for both variants. When meta-analysis was performed in male and female case-control subsets, an increased and gender-specific effect of allele on risk of disease was found in females for both SNPs with no significant effect in males, which was further associated with a gender-specific effect on gene expression. In conclusion, using a large European-wide sample we were able to replicate the gender-specific association previously found in a UK cohort.

Obesity decreases the oxidant stress induced by tobacco smoke in a rat model.

Obesity and emphysema are associated with low-grade systemic inflammation and oxidant stress. Assuming that the oxidant stress induced by emphysema would be decreased by obesity, we analyzed the oxidant/antioxidant state in a rat model combining both diseases simultaneously. Obesity was induced using sucrose, while emphysema by exposure to tobacco smoke. End-points evaluated were: body weight, abdominal fat, plasma dyslipidemia and malondialdehyde (MDA), insulin and glucose AUC, activities of Mn-superoxide dismutase (Mn-SOD), glutathione reductase (GR), glutathione transferase (GST) and glutathione peroxidase (GPx); lung MnSOD and 3-nitrotyrosine (3-NT) immunostaining, and expression of αV and ß6 integrin subunits. In rats with obesity, the body weight, abdominal fat, plasma triglyceride levels, glucose AUC, insulin levels, GST activity, and αV and ß6 integrin expressions were amplified. The rats with emphysema had lower values of body weight, abdominal fat, plasma insulin, triglycerides and glucose AUC but higher values of plasma MDA, GPx activity, and the lung expression of the αV and ß6 integrins. The combination of obesity and emphysema compared to either condition alone led to diminished body weight, abdominal fat, plasma insulin MDA levels, GPx and GST activities, and αV and ß6 integrin expressions; these parameters were all previously increased by obesity. Immunostaining for MnSOD augmented in all experimental groups, but the staining for 3-NT only increased in rats treated with tobacco alone or combined with sucrose. Results showed that obesity reduces oxidant stress and integrin expression, increasing antioxidant enzyme activities; these changes seem to partly contribute to a protective mechanism of obesity against emphysema development.

Allelic variants in the zinc transporter-3 gene, SLC30A3, a candidate gene identified from gene expression studies, show gender-specific association with schizophrenia.

Previous microarray analysis of gene expression in frontal cortex showed differential expression of genes associated with synaptic function in schizophrenia compared to matched-controls in two independent cohorts. One of these genes validated in both cohorts, SLC30A3, which encodes the Zinc Transporter 3 (ZNT3), is localised to synaptic vesicles in glutamate synapses and known to be involved in cognitive function. In view of the robust depletion of SLC30A3 mRNA in two independent studies and the importance of this gene in cognitive function, we investigated whether single nucleotide polymorphism (SNP) associations with schizophrenia could be detected in a UK case controlled schizophrenia cohort. Four SNPs were selected across this gene and genotyped in a cohort of cases and controls from East UK. We found significant associations with schizophrenia at the allelic (ORs: 1.51 to 1.57), genotype (ORs: 1.46 to 1.53) and haplotype level (P=2.15×10(-4)). These associations proved to be gender-specific with significant effects of allele (ORs: 1.74 to 2.11), genotype (ORs: 1.78 to 2.14) and haplotype (P=3.51×10(-5)) observed in female schizophrenia cases but not males, when split by gender. In conclusion, SNPs in SLC30A3 showed a gender-specific association with schizophrenia in this East UK cohort, which merits further investigation in other population samples.

Evaluación de la cultura sobre seguridad del paciente entre médicos residentes de Medicina familiar y comunitaria en un servicio de urgencias hospitalario / Evaluation of patient safety culture among family and community medicine residents in a hospital A and E department

Fundamento. La mejora de la seguridad de los pacientes es prioritaria en los centros sanitarios. En los programas de las especialidades no aparece como un área de aprendizaje específica. El objetivo de este trabajo es evaluar la cultura de seguridad de los MIR de Medicina de Familia. Material y métodos. Estudio descriptivo transversal. Como cuestionario se utilizó la versión española del “Hospital Survey on Patient Safety”. Se determinaron las fortalezas y oportunidades de mejora del servicio de Urgencias. Resultados. La dimensión mejor valorada fue el trabajo en equipo en urgencias. Las peor calificadas fueron “dotación de personal” y “apoyo de la gerencia”. Ningún encuestado había notificado incidentes en el servicio. Conclusiones. Existe, entre los MIR encuestados, un desconocimiento de las vías para notificar eventos adversos, así como una deficiencia formativa en cultura de seguridad. Ésta debería potenciarse en la formación de los especialistas en Medicina Familiar y Comunitaria (AU)

Background. Improving patient safety is a priority in all health care centres. It does not appear as a specific area of training in specialty programs. The aim of this study is to evaluate the safety culture of Family Medicine residents (MIR - Médico Interno Residente/Medical Internship and Residency).Methods. Transversal descriptive study. The Spanish version of the “Hospital Survey on Patient Safety” questionnaire was used. Strengths and opportunities for improving the service of the A & E Department were determined. Results. The most highly valued dimension was team work in the A & E Department. The worst qualified were “staffing” and “management support”. None of those surveyed had notified any incidents in the unit. Conclusions. Amongst the MIR surveyed there is a lack of knowledge about the channels for notifying adverse events, as well as a training deficiency in safety culture. This should be strengthened in the training of specialists in Family and Community Medicine (AU)

Oxidative stress and lung injury induced by short-term exposure to wood smoke in guinea pigs.

Oxidative stress and lung injury induced by short-term exposure to wood smoke were evaluated in guinea pigs through cell profile, bronchoalveolar lavage (BAL), conventional histology and immunohistochemistry (4-hydroxynonenal, 3-nitrotyrosine, Mn-superoxide dismutase, heme oxygenase-1); malondialdehyde and 4-hydroxynonenal concentration, Mn-superoxide dismutase, glutathione reductase, glutathione peroxidase, and catalase activities in plasma, lung and BAL. Total cells increased in BAL, and the percentage of macrophages, neutrophils and lymphocytes augmented (72-96 h). Histopathological examination of lung tissues showed mild thickening of membranous bronchiole walls, infiltration of foamy macrophages and polymorphonuclear leukocytes in bronchial, bronchiolar and intraalveolar spaces. Goblet cell hyperplasia was also observed in bronchial and bronchiolar epithelia. Plasma malondialdehyde concentration was increased at all times, while 4-hydroxynonenal was increased only in plasma and BAL after 24 h. Plasma glutathione reductase activity increased at 24 and 72 h, BAL glutathione peroxidase activity decreased at 72 and 96 h, whereas catalase activity increased in plasma at 72 h, and decreased in BAL at 24 h. Immunostaining intensity to 4-hydroxynonenal, 3-nitrotyrosine, Mn-superoxide dismutase and heme oxygenase-1 was enhanced mainly in macrophages, bronchial/bronchiolar epithelial cells and type II pneumocytes after 72-96 h of wood smoke exposure. Overall, short-term exposure to wood smoke induces alterations in oxidative/antioxidant state in lung and airway injury, similar to those observed in humans with domestic exposure.

[Evaluation of patient safety culture among family and community medicine residents in a hospital A& E department]. / Evaluación de la cultura sobre seguridad del paciente entre médicos residentes de medicina familiar y comunitaria en un servicio de urgencias hospita.

BACKGROUND: Improving patient safety is a priority in all health care centres. It does not appear as a specific area of training in specialty programs. The aim of this study is to evaluate the safety culture of Family Medicine residents (MIR - Médico Interno Residente/Medical Internship and Residency). METHODS: Transversal descriptive study. The Spanish version of the "Hospital Survey on Patient Safety" questionnaire was used. Strengths and opportunities for improving the service of the A & E Department were determined. RESULTS: The most highly valued dimension was teamwork in the A & E Department. The worst qualified were "staffing" and "management support". None of those surveyed had notified any incidents in the unit. CONCLUSIONS: Amongst the MIR surveyed there is a lack of knowledge about the channels for notifying adverse events, as well as a training deficiency in safety culture. This should be strengthened in the training of specialists in Family and Community Medicine.

Upregulation of NKG2D ligands and enhanced natural killer cell cytotoxicity by hydralazine and valproate.

Natural killer cells play a role in the immune antitumor response by recognizing and eliminating tumor cells through the engagement of NKG2D receptors with their ligands on target cells. This work aimed to investigate whether epigenetic drugs are able to increase MICA and MICB expression as well as NK cell cytotoxicity. Prostate, colon, breast and cervical cancer cell lines were analyzed for the expression of MICA and MICB at the mRNA and protein levels by RT-PCR, Western blot, flow cytometry and ELISA. The activating mark H3K4m2 at the MICA and MICB promoters was investigated by ChIP assays. Cytotoxicity of NK cells against the target epithelial cancer cells was investigated with the CD107 cytotoxicity assay. The results show that hydralazine and valproic acid not only increase the expression of MICA and MICB ligands of target cells, but also reduce their shedding to the supernatant. This upregulation occurs at the transcriptional level as revealed by increase of the H3K4 activating mark at the promoter of MICA and MICB genes. These effects are paralleled by increased cytotoxicity of NK cells, which was attenuated at different degrees by using blocking antibodies against the NKG2D receptor and ligands. In conclusion, our results demonstrate the ability of hydralazine and valproate to increase the NK activity against epithelial cancer cell lines and suggest that these drugs could reduce the levels of soluble MICA and MICB helping in avoiding tumor-induced suppression of NK cytotoxicity against the tumor.

Pharmacokinetics of hydralazine, an antihypertensive and DNA-demethylating agent, using controlled-release formulations designed for use in dosing schedules based on the acetylator phenotype.

PURPOSE: The antihypertensive hydralazine has recently been repositioned as DNA demethylating for the epigenetic therapy of cancer. As the acetylator phenotype is the key determinant of its plasma levels, the dose of hydralazine needs to be adjusted for the acetylation status of patients. METHODS: The pharmacokinetics of orally administered hydralazine was evaluated in 26 healthy volunteers (13 slow and 13 fast acetylators) after a single dose of 182 mg administered as a controlled-release tablet. Plasma levels of hydralazine were analyzed in 85 cancer patients treated with this formulation at a dose of 83 mg/day and 182 mg/day for slow and fast acetylators, respectively. RESULTS: The C(max) and t(max) of hydralazine for fast acetylators were 208.4 ± 56.9 SD ng/ml and 2.8 ± 2.5 h, respectively. The corresponding results for slow acetylators were 470.4 ± 162.8 ng/ml, and 4.4 ± 3.1 h. Healthy volunteers who were fast acetylators had no clinically significant changes in blood pressure and heart rate or any other side-effect, however, slow acetylators had transient episodes of headache, tachycardia and faintness. Among 85 cancer patients that received either 182 mg or 83 mg of hydralazine daily, according to their acetylator status, the mean concentrations of hydralazine in plasma were 239.1 ng/ml and 259.2 ng/ml for fast and slow acetylators, respectively. These differences were not significantly different, p = 0.3868. CONCLUSIONS: The administration of dose-adjusted controlled-release hydralazine according to the acetylation status of cancer patients yields similar levels of hydralazine.

Epigenetic therapy and cisplatin chemoradiation in FIGO stage IIIB cervical cancer.

INTRODUCTION: This trial aimed to evaluate the safety and efficacy of epigenetic therapy associated with cisplatin chemoradiation in FIGO Stage IIIB patients. METHODS: Hydralazine containing either 182 mg for rapid-, or 83 mg for slow acetylators and magnesium valproate were administered at 30 mg/kg tid. Both drugs were taken until intracavitary therapy was finished. Pelvic external beam radiation and low-dose rate brachytherapy were administered at a total cumulative dose to point A of at least 85 Gy. Weekly cisplatin at 40 mg/m2 was delivered for six cycles. RESULTS: Twenty-two patients were included and 18 (82%) patients completed treatment. Mean dose to point A was 84.6 + 2.2. Median number of cisplatin cycles was 5.5 (range, 1-6). Brachytherapy was delayed for technical reasons; the mean overall treatment time was 11.8 weeks. Grade 3 anemia, leucopenia, neutropenia, and thrombocytopenia were observed in 9%, 45%, 45%, and 9% of patients, respectively. CONCLUSIONS: Hydralazine and valproate are well-tolerated and safe when administered with cisplatin chemoradiation. Unfortunately, the suboptimal administration of brachytherapy for technical reasons in this study, precluded assessing the efficacy of epigenetic therapy. However, the tolerability of this regimen administered concurrent to radiation needs to be further tested.

Pharmacogenetics and pharmacoepigenetics of gemcitabine.

Gemcitabine (2',2'-difluoro 2'deoxycytidine, dFdC) is an analog of cytosine with distinctive pharmacological properties and a wide antitumor-activity spectrum. The pharmacological characteristics of gemcitabine are unique because two main classes of genes are essential for its antitumor effects: membrane transporter protein-coding genes, whose products are responsible for drug intracellular uptake, as well as enzyme-coding genes, which catalyze its activation and inactivation. The study of the pharmacogenetics and pharmacoepigenetics of these two gene classes is greatly required to optimize the drug's therapeutic use in cancer. This review aims to provide an update of genetic and epigenetic bases that may account for interindividual variation in therapeutic outcome exhibited by gemcitabine.

A phase II study of epigenetic therapy with hydralazine and magnesium valproate to overcome chemotherapy resistance in refractory solid tumors.

BACKGROUND: Epigenetic aberrations lead to chemotherapy resistance; hence, their reversal by inhibitors of DNA methylation and histone deacetylases may overcome it. PATIENTS AND METHODS: Phase II, single-arm study of hydralazine and magnesium valproate added to the same schedule of chemotherapy on which patients were progressing. Schedules comprised cisplatin, carboplatin, paclitaxel, vinorelbine, gemcitabine, pemetrexed, topotecan, doxorubicin, cyclophosphamide, and anastrozole. Patients received hydralazine at 182 mg for rapid, or 83 mg for slow, acetylators, and magnesium valproate at 40 mg/kg, beginning a week before chemotherapy. Response, toxicity, DNA methylation, histone deacetylase activity, plasma valproic acid, and hydralazine levels were evaluated. RESULTS: Seventeen patients were evaluable for toxicity and 15 for response. Primary sites included cervix (3), breast (3), lung (1), testis (1), and ovarian (7) carcinomas. A clinical benefit was observed in 12 (80%) patients: four PR, and eight SD. The most significant toxicity was hematologic. Reduction in global DNA methylation, histone deacetylase activity, and promoter demethylation were observed. CONCLUSIONS: The clinical benefit noted with the epigenetic agents hydralazine and valproate in this selected patient population progressing to chemotherapy' and re-challenged with the same chemotherapy schedule after initiating hydralazine and valproate' lends support to the epigenetic-driven tumor-cell chemoresistance hypothesis (ClinicalTrials.gov Identifier: NCT00404508).

EGF-grafted PDMS surfaces in artificial cornea applications.

Lack of epithelial cell coverage has remained a persistent problem in the design of an artificial cornea. In this work, polydimethylsiloxane (PDMS) surfaces were modified with epidermal growth factor (EGF) to improve the growth of corneal epithelial cells. The EGF was covalently tethered to PDMS substrates aminated by plasma polymerization of allylamine via a homobifunctional polyethylene glycol (PEG) spacer. Surface modification was confirmed by contact angle and X-ray photoelectron spectroscopy measurements. By varying the ratio of EGF to PEG from 1:50 to 1:5, EGF amounts from 40 to 90 ng/cm2 could be bound, as determined by surface plasmon resonance (SPR) and 125I radiolabelling. Human corneal epithelial cells on the various modified surfaces were cultured both in the presence and absence of EGF in the culture medium to determine the effect of covalently bound EGF on the cells. The results demonstrated that covalently bound EGF on the surfaces is active with respect to promoting epithelial cell coverage. This was significant when compared to unmodified controls.

Detección in vivo mediante RAPD de alteraciones en el ADN producidas por benzo(a)pireno / In vivo detection of DNA alterations produced by Benzo(a)pyrene using the RAPD technique

L a técnica de RAPD (Amplificación al Azar de ADN Polimórfico) permite detectar alteraciones inespecíficas en el ADN procedente de células que poseen una dotación genética idéntica, como son las líneas celulares establecidas, mediante la comparación del patrón de bandas de las células expuestas y no expuestas a la acción de genotóxicos.En los últimos años hemos desarrollado una metodología sensible y reproducible utilizando la línea celular RTG-2, derivada de trucha arco iris (Oncorhynchus mykiss). Sin embargo, es preciso comprobar la capacidad predictiva de este ensayo mediante estudios in vivo. La línea celular RTG-2, como se ha evidenciado en trabajos anteriores, presenta una gran similitud genética con la especie de la que procede. Por ello, en este trabajo, se ha llevado a cabo -una -exposición -subletal a benzo(a)pireno mediante inyección intraperitoneal de 69 mg/g de p.c. en alevines de trucha arco iris, valorando la aparición de mutaciones mediante la comparación del patrón de bandas obtenido a partir del ADN de células de sangre periférica, a diferentes tiempos (1 - 3 meses). Debido a que la presencia de bandas polimórficas dificulta el análisis entre los grupos de individuos tratados y no tratados, las comparaciones se realizaron en un mismo individuo antes y después del tratamiento. Los análisis cualitativos y cuantitativos mostraron tanto la aparición de nuevas bandas, como alteraciones en Su intensidad confirmando, de esta manera, los resultados que previamente habíamos obtenido in vitro tras exposiciones a este mismo genotóxico (AU)

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Neuroendocrine marker expression in cervical carcinomas of non-small cell type.

Small-cell carcinomas of the uterine cervix are highly aggressive tumors. Up to 100% of these tumors express at least one neuroendocrine marker such as neuron-specific enolase (NSE), chromogranin A (CgA), and synaptophysin (SYN). In other tumor types such as non-small-cell carcinomas of the lung, colon, and prostate, the presence of these markers has been associated with a better prognosis in some studies, a worsened prognosis in others, or has had no prognostic effect in still other studies. However, little is known about their expression and prognostic significance in the common "non-small-cell" carcinomas of the uterine cervix. The primary tumors of 54 previously untreated patients with histologically confirmed non-small-cell carcinoma of the cervix uteri (squamous carcinoma, adenosquamous carcinoma, and adenocarcinoma) were analyzed by immunohistochemistry for expression of NSE, CgA, and SYN. The expression status was correlated to pathological characteristics and outcome. In addition, the expression of these markers was investigated in cervical carcinoma cell lines. None of the 54 tumors expressed NSE or CgA, although SYN was positive in five tumors (9%) of which four were squamous and one was adenocarcinoma. These five patients relapsed within the first 6 months of follow-up and four have died. Among eight cancer cell lines only one was positive for CgA and another one for SYN. We conclude that the neuroendocrine marker SYN is expressed in a small subset of non-small-cell carcinomas of the cervix and its expression seems to correlate with a poor outcome.

Correlation of tumor growth index with early treatment response in cervical carcinoma.

Despite the recent progress in the management of cervical carcinoma, treatment failure is quite common and therefore it is necessary to identify predicting factors for tumor response. It is known that both cell proliferation and apoptosis determine the tumor growth index (TGI) which reflects the overall contribution of gene defects. Here we explored whether the TGI index could be a better predictor of response in comparison to cell proliferation or apoptosis as separate phenomena. Twenty-five patients with cervical carcinoma treated with radiation alone or neoadjuvant chemotherapy plus surgery were analyzed. Cell proliferation and apoptosis determined by PCNA immunohistochemical expression and tumor nucleosomes by ELISA, respectively, were used to calculate the TGI, which was analyzed with regard to early tumor response. Our results show that most patients with a negative TGI had early response suggesting increased tumor sensitivity(p = 0.0186). On the other hand, patients with a positive TGI were more resistant to treatment. TGI was not related to age, clinical stage or tumor size. In conclusion, the results of this study show that the determination of the TGI, but no cell proliferation or apoptosis, as separate events, is able to predict an early treatment response to either radiation or chemotherapy in cervical carcinoma.

P53 plays a protective role against UV- and cisplatin-induced apoptosis in transcription-coupled repair proficient fibroblasts.

We previously reported that transcription-coupled repair (TCR)-deficient human fibroblasts are extremely sensitive to UV-induced apoptosis and this sensitivity correlated with the induction of the p53 tumour suppressor. However, we have also found that p53 can be protective against UV-induced apoptosis. Thus, prior to this study, it was not clear whether the induction of p53 in TCR-deficient fibroblasts contributed to their death. To address this issue, we have expressed human papillomavirus E6 (HPV-E6) in primary fibroblasts derived from patients affected with xeroderma pigmentosum (complementation groups A, B and C) and Cockayne syndrome (complementation group B). We found that TCR-deficient (XP-A, XP-B and CS-B) fibroblasts were more sensitive than TCR-proficient cells (XP-C and normal) to both UV light and cisplatin treatment and this increase in sensitivity was not p53 dependent. Importantly, HPV-E6 expression increased the sensitivity of TCR-proficient normal and XP-C fibroblasts to UV- and cisplatin-induced apoptosis. This increase in sensitivity correlated with a decrease in the capacity of HPV-E6 expressing cells to recover mRNA synthesis following UV-irradiation. Therefore, we propose that p53 protects against UV- and cisplatin-induced apoptosis in a TCR-dependent manner and that p53 does not contribute strongly to the induction of apoptosis in TCR-deficient fibroblasts.

Membrane proteins in neoplasic and normal uterine cervix.

Tumor cells exhibit phenotypic and genotypic differences in comparison to normal cells. These differences can be used to identify proteins important for tumor growth and, therefore, potentially used in the diagnosis and follow-up of patients. The objective of this work was to investigate the electrophoretic pattern of cytoplasm membrane proteins from normal and malignant cervix using polyacrylamide-SDS gels. A highly reproducible protein pattern was found in the 29 samples of normal cervix whereas three well-defined patterns of protein bands were observed in the 48 tumor specimens (pattern I: 25%, pattern II: 29.2% and pattern III: 45.8%). A low concentration or absence of high molecular weight proteins was observed (p<0.5) in tumor samples. None of the tumor protein patterns correlated with the clinicopathologic characteristics of patients. Nine out of 11 patients (82%) showing the pattern III had a complete clinical response whereas only 55% (11 out of 20) of those with patterns I and II showed a complete response. However, this difference was non-significant (p=0.1247). In conclusion, we demonstrate that there is a gain and loss of cytoplasmic membrane proteins in tumors, shown as different protein band patterns. These findings could have clinical and biological significance that must be further evaluated.

DNA fingerprint comparison of rainbow trout and RTG-2 cell line using random amplified polymorphic DNA.

The detection of genotoxic effects using in vitro cell systems can be extremely useful in risk assessment procedures. However, care should be taken in the extrapolation of in vitro results since, amongst other factors, established cell lines may deviate from the genetic characteristics of their species. In this work, the genetic similarities between the RTG-2 cell line and rainbow trout individuals (Oncorhynchus mykiss) from several fish farms have been studied by the RAPD technique. Results show a significant analogy in the band patterns obtained for both systems, up to 73% of the bands composing the fingerprint of the RTG-2 cell line were found in all the individuals analysed. The inter-population similarity index (Lynch, 1990), considering the RTG-2 cell line as a population, gives a value of 0.931 between both systems. The dendrogram constructed from all the individuals, considering the RTG-2 cell line as just another individual of a single population, showed that the genetic structure of the cell line was not different from those of the other individuals tested. The strong genetic similarity of both systems, together with the previously proven capability of the RAPD technique to detect genetic alterations caused in vitro by genotoxic agents, can be very useful in genetic ecotoxicological studies.