Differential disruption on glucose and insulin metabolism in two rat models of diet-induced obesity, based on carbohydrates or lipids.

Obesity is a relevant health public issue and is the main factor for glucose metabolism dysregulation and diabetes progression; however, the differential role of a high-fat diet or high sugar diet consumption on glucose metabolism and insulin processing is not well understood and has been scarcely described. Our research aimed to analyze the effects of chronic consumption of both high sucrose and high-fat diets on glucose and insulin metabolism regulation. Wistar rats were fed with high-sugar or high-fat diets for 12 months; after that, fasting glucose and insulin levels were measured along with a glucose tolerance test (GTT). Proteins related to insulin synthesis and secretion were quantified in pancreas homogenates, whereas islets were isolated to analyze ROS generation and size measurement. Our results show that both diets induce metabolic syndrome, linked with central obesity, hyperglycemia, and insulin resistance. We observed alterations in the expression of proteins related with insulin synthesis and secretion, along with diminution of Langerhans islets size. Interestingly, the severity and number of alterations were more evident in the high-sugar diet than in the high-fat diet group. In conclusion, obesity and glucose metabolism dysregulation induced by carbohydrate consumption, led to worst outcomes than high-fat diet.

Chronic exposure to ozone induces cardiac antioxidant response and overexpression of either mitochondrial fision protein DRP1 and hipertrophyc-related proteins.

Pollution is considered a risk factor for cardiovascular disease; however, the mechanisms to explain this relationship are not well understood; ozone is one of the most abundant and studied air contaminants. Our study aimed to evaluate the effect of chronic exposition of rats to controlled low doses of ozone on oxidative stress, apoptosis, mitochondrial dynamics, and cardiac hypertrophy. Male Wistar rats were daily exposed to low ozone doses during 7, 15, 30, and 60 days, 4 h/day. Hearts were dissected, and homogenates were prepared. Oxidative stress was evaluated by TBARS and protein nitrosylation in addition to Superoxide dismutase 1 (SOD1) and Catalase levels; the apoptosis related-proteins caspase 3, caspase 9, Bax, Bcl-2, and the mitochondrial dynamic-associated proteins Fis1, Drp1, OPA1, and Mfn1 were quantified by western blot among the cardiac hypertrophy indicator alpha-actin (cardiac actin). There were no changes in the oxidative stress markers, however SOD1 expression increases. Caspase 3 expression decreased, whereas caspase 9 increased without changes in Bax or Bcl-2. Mitochondrial fission may be favored according to the increased expression of Drp1 but not changes in fusion-related proteins OPA1 and Mfn1. Finally, the molecular marker for cardiac hypertrophy was overexpressed after 30 and 60 days of ozone exposition. The chronic exposition to ozone induces a deleterious effect on cardiac mitochondria. Antioxidant defenses also show changes in relation to exposure time, as well as an apparent pro-hypertrophic effect associated with altered mitochondrial dynamics.

Prevalence of sexually transmitted pathogens associated with HPV infection in cervical samples in a Mexican population.

Cervical cancer development has been mainly associated with persistent human papillomavirus (HPV) infections. However, HPV infection is unlikely to be sufficient to cause cervical cancer, and the contribution of other sexually transmitted infections (STIs) could be the determining factor for cervical lesion-progression. The aim of this study was to estimate the prevalence of STIs associated with HPV-positivity in 201 cervical samples from patients who underwent annual routine gynecological exams. The overall prevalence of STIs was 57.7%, and the most frequent infection was Ureaplasma spp (UP) (39.8%), followed by Gardnerella vaginalis (GV) (25.9%), α-HPV (18.4%), Chlamydia trachomatis (CT) (1.5%), and Mycoplasma genitalium (MG) (0.5%). The highest prevalence rate of multiple non-HPV infections was observed for the age-range 31-40; for papillomavirus infection, the age-range was 21-30. In normal cervical samples, HPV16 was the most prevalent genotype (24.3%), followed by genotypes 58 (13.5%) and 52 (10.8%). Intriguingly, HPV18 was not detected in the study population, and genotypes 52 and 58 were found exclusively in samples with abnormal cytology. Papillomavirus infection with oncogenic types was significantly associated with GV (P = 0.025) and strongly associated with multiple non-HPV pathogens (P = 0.002). The following variables correlated significantly with cytological diagnosis of low-grade squamous intraepithelial lesion (LSIL): GV (P = 0.028), multiple non-HPV infections (P = 0.001), and high-risk HPV positivity (P = 0.001). Epidemiological data from this study will contribute to the molecular detection of sexually transmitted pathogens from screening programs to identify those women who are at risk for developing cervical lesions.

Promising predictive molecular biomarkers for cervical cancer (Review).

Cervical cancer (CC) constitutes a serious public health problem. Vaccination and screening programs have notably reduced the incidence of CC worldwide by >80%; however, the mortality rate in low­income countries remains high. The staging of CC is a determining factor in therapeutic strategies: The clinical management of early stages of CC includes surgery and/or radiotherapy, whereas radiotherapy and/or concurrent chemotherapy are the recommended therapeutic strategies for locally advanced CC. The histopathological characteristics of tumors can effectively serve as prognostic markers of radiotherapy response; however, the efficacy rate of radiotherapy may significantly differ among cancer patients. Failure of radiotherapy is commonly associated with a higher risk of recurrence, persistence and metastasis; therefore, radioresistance remains the most important and unresolved clinical problem. This condition highlights the importance of precision medicine in searching for possible predictive biomarkers to timely identify patients at risk of treatment response failure and provide tailored therapeutic strategies according to genetic and epigenetic characteristics. The present review aimed to summarize the evidence that supports the role of several proteins, methylation markers and non­coding RNAs as potential predictive biomarkers for CC.

Gene expression of cardiovascular risk markers in mononuclear cells of pregnant woman in relation to plasma leptin and homocysteine levels: A cross sectional study.

OBJECTIVE: To investigate the relationship between anthropometric, biochemical, and hematologic parameters and serum leptin and homocysteine (Hcy) levels. Also, to determine the effect of leptin and Hcy on expression of genes associated with cardiovascular disease susceptibility (APOA1, LRP1, COX-1, and COX-2) in mononuclear cells of healthy pregnant women. METHODS: Between August 2018 and January 2020, a cross-sectional study was conducted on 161 healthy pregnant women in Tabasco, southeastern Mexico. The study population was classified by trimester, according to gestational pregnancy. Anthropometric, biochemical (leptin and homocysteine), and hematologic data were obtained under fasting conditions. APOA1, LRP1, COX-1, and COX-2 expression in mononuclear cells was evaluated using RT-qPCR. RESULTS: Red cell indices (hemoglobin, hematocrit, and erythrocytes) were negatively and positively correlated with leptin and Hcy levels, respectively, in the first- and second-trimester groups. Increased leptin levels and low red cell indices were significantly associated with BMI <25.0 in the second-trimester group; however, no significant differences were observed in Hcy levels. Increased leptin and Hcy levels were significantly associated with high lipid indicators in the first- and third-trimester groups, respectively. High APOA1 and COX-2 expression was significantly associated with reduced leptin and increased Hcy levels in the second- and third-trimester groups. CONCLUSION: Increased leptin and Hcy levels during pregnancy, mainly associated with modifications in erythrocytes and lipid indices, may lead to early modification of genes related to lipid metabolism (APOA1) and proinflammatory response (COX-2) and, thereby, increase cardiovascular disease risk.

Chronic consumption of imbalance diets high in sucrose or fat induces abdominal obesity with different pattern of metabolic disturbances and lost in Langerhans cells population.

AIM: Obesity is a worldwide health issue, associated with development of type 2 Diabetes Mellitus. The aim of this study is to analyze the effect of consumption of two hypercaloric diets on metabolic disturbance and beta cells damage. MAIN METHODS: Male Wistar rats were subjected to twelve months consumption of three diets: a Control balanced diet (CTD, carbohydrates 58 %, proteins 29 %, lipids 13 %) and two hypercaloric diets, high in sucrose (HSD, carbohydrates 68 %, proteins 22 %, lipids 10 %) or high in fat (HFD, carbohydrates 31 %, proteins 14 %, lipids 55 %). Serum levels of glucose, triglycerides and free fatty acids were measured after zoometric parameters determination. Antioxidant enzymes activity and oxidative stress-marker were measured in pancreas tissue among histological analysis of Langerhans islets. KEY FINDINGS: Although diets were hypercaloric, the amount of food consumed by rats decreased, resulting in an equal caloric consumption. The HSD induced hypertriglyceridemia and hyperglycemia with higher levels in free fatty acids (FFA, lipotoxicity); whereas HFD did not increased neither the triglycerides nor FFA, nevertheless the loss of islets' cell was larger. Both diets induced obesity with hyperglycemia and significant reduction in Langerhans islets size. SIGNIFICANCE: Our results demonstrate that consumption of HSD induces more significant metabolic disturbances that HFD, although both generated pancreas damage; as well hypercaloric diet consumption is not indispensable to becoming obese; the chronic consumption of unbalanced diets (rich in carbohydrates or lipids) may lead to abdominal obesity with metabolic and functional disturbances, although the total amount of calories are similar.

Modulating epigenetic modifications for cancer therapy (Review).

Cancer is a global public health concern. Alterations in epigenetic processes are among the earliest genomic aberrations occurring during cancer development and are closely related to progression. Unlike genetic mutations, aberrations in epigenetic processes are reversible, which opens the possibility for novel pharmacological treatments. Non­coding RNAs (ncRNAs) represent an essential epigenetic mechanism, and emerging evidence links ncRNAs to carcinogenesis. Epigenetic drugs (epidrugs) are a group of promising target therapies for cancer treatment acting as coadjuvants to reverse drug resistance in cancer. The present review describes central epigenetic aberrations during malignant transformation and explains how epidrugs target DNA methylation, histone modifications and ncRNAs. Furthermore, clinical trials focused on evaluating the effect of these epidrugs alone or in combination with other anticancer therapies and other ncRNA­based therapies are discussed. The use of epidrugs promises to be an effective tool for reversing drug resistance in some patients with cancer.

High sugar but not high fat diet consumption induces hepatic metabolic disruption and up-regulation of mitochondrial fission-associated protein Drp1 in a model of moderate obesity.

Identification of new modifications and the association with diet patterns are essential for the prevention of non-alcoholic fatty liver disease (NAFLD). To address this problem, we feed rats with high caloric diets based on high sucrose (HSD) and high fat (HFD) and analysed metabolic and mitochondrial alterations. Both diets induce moderated obesity and fat accumulation in the liver after 8, 10 and 12 months of diet. The HSD induces both hyperleptinemia and hyperinsulinemia, as well as up-regulation of transcription factors SRBEP1 and PPARγ along slight increase nitrosylation of proteins and increased mitochondrial fission. In contrast, HFD induced hyperleptinemia without changes in neither insulin levels nor oxidative stress, SREBP1, PPARγ, or mitochondrial dynamics. In conclusion, chronic consumption of high sucrose content diets induces more pathological and metabolic alteration in liver in comparison with consumption of high-fat content diets, although both induces obesity and liver steatosis in these animal models.

Anthropometric, biochemical, and haematological indicators associated with hyperhomocysteinemia and their relation to global DNA methylation in a young adult population.

Increased homocysteine (Hcy) levels have been associated with a higher risk of cardiovascular and neurodegenerative diseases. Passive DNA demethylation has been suggested as one of the mechanisms implicated in the development of these conditions, and most studies have investigated this relationship in older adult populations. Therefore, this study aimed to evaluate the relationship between corporal composition and biochemical and haematological indicators with plasma homocysteine levels and genome-wide methylation (Alu, LINE-1, and SAT2) in a population of healthy young adults (median age, 18 years). We showed that the prevalence of hyperhomocysteinemia was significantly higher in men (18.5%) than in women (6.6%) (P = 0.034). Increased Hcy level was substantially associated with higher levels of body mass index and visceral fat in females, whereas in males, it was significantly associated with reduced red cell distribution width and high-density lipoprotein (HDL) cholesterol (HDL-C) levels and increased low-density lipoprotein/HDL ratio. Hypomethylation of Alu was significantly associated with reduced levels of HDL-C (<40.0 mg dL-1), whereas hypomethylation of LINE-1 and SAT2 was significantly associated with higher levels of skeletal muscle (<39.3%) in males. These results highlight the participation of hormonal factors in regulating Hcy metabolism, primarily in the female population, whereas changes in DNA methylation observed in males might be associated with the consumption of a protein diet with high levels of methionine, independent of increased Hcy levels.

Hydralazine and magnesium valproate as epigenetic treatment for myelodysplastic syndrome. Preliminary results of a phase-II trial.

Decitabine and azacitidine, two DNA methyltransferase (DNMT) inhibitors, are the current standard of treatment for myelodysplastic syndrome (MDS). Histone deacetylase (HDAC) inhibitors are also being tested against MDS. Both drug classes synergize in their gene reactivating and anticancer activities. The combination of hydralazine and valproate (Transkrip®), a DNMT and HDAC inhibitor, respectively), has been developed as epigenetic therapy under the drug repositioning concept. To evaluate the clinical efficacy and safety of hydralazine and valproate against MDS, an open phase-II study for previously treated patients with MDS was conducted. The hydralazine dose was given according with the acetylator phenotype, and valproate was dosed at 30 mg/kg/day. Response was graded with International Working Group criteria. Toxicity was evaluated by the Common Toxemia Criteria-National Cancer Institute version 3 scale. From November 2007 to January 2010, 12 patients were included. Median age±SD was 53±19.78 years (range, 23-79 years); median time from diagnosis to inclusion in the study was 7.9 months (range 2.6-36.1 months). Median of previous treatment was 2 (range, 1-6). Refractory cytopenia with multilineage dysplasia was diagnosed in ten cases, and refractory anemia with excess of blasts in two. Overall response was documented in six (50%) of 12 cases, including one CR, one PR, and four hematological improvements of the erythroid series. Two patients (16.6%) progressed to acute myeloid leukemia. Hemoglobin increased from 7.4 to 10.3 g/dL (in 13 weeks), neutrophils, from 1.1 to 2.0 (in 3 weeks), and platelets, from 66×10(9) to 72×10(9)/L (in 2 weeks). Transfusional requirements decreased from 2.3 to 0 U bi-monthly for red blood cells and from 0.5 to 0 U bi-monthly for platelets in responding patients. Main toxicities were mild, including somnolence and nausea. Preliminary results of this phase-II study suggest that the combination of hydralazine and valproate is a promising non-toxic and effective therapy for MDS.

Albendazole Release from Silica-Chitosan Nanospheres. In Vitro Study on Cervix Cancer Cell Lines.

In this work, a pH-responsive drug-carrier based on chitosan-silica nanospheres was developed as a carrier for Albendazole (ABZ), a poorly water-soluble anthelmintic drug. Spherical silica nanoparticles were obtained by Stöber method and further etched to obtain mesoporous particles with sizes ranging from 350 to 400 nm. The specific BET area of nanoparticles increased from 15 m2/g to 150 m2/g for etched silica, which also exhibited a uniform pore size distribution. X-ray powder diffraction showed the presence of amorphous phase of silica and a low-intensity peak attributed to ABZ for the drug-loaded nanoparticles. A uniform layer of chitosan was obtained ranging from 10 to 15 nm in thickness due to the small concentration of chitosan used (0.45 mg of chitosan/mg of SiO2). The in vitro evaluation of hybrid nanoparticles was performed using four cervical cancer cell lines CaSki, HeLa, SiHa and C33A, showing a significant reduction in cell proliferation (>85%) after 72 h. Therefore, we confirmed the encapsulation and bioavailability of the drug, which was released in a controlled way, and the presence of chitosan delayed the release, which could be of interest for the development of prolonged release drug delivery systems.

The high-risk HPV E6 proteins modify the activity of the eIF4E protein via the MEK/ERK and AKT/PKB pathways.

Previous studies have proposed that the human papillomavirus (HPV) E6 oncoproteins modify the transcriptional activity of eIF4E through mechanisms dependent on p53 degradation. However, the effect of these oncoproteins on pathways regulating the activity of the eIF4E protein remains poorly understood. Hence, we investigated the mechanisms whereby E6 proteins regulate the activity of the eIF4E protein and its effect on target genes. Overexpression of E6 constructs (HPV-6, HPV-16, HPV-18, and HPV52) showed that E6 oncoproteins increased phosphorylation of the eIF4E protein (Serine-209). This result was mainly mediated by phosphorylation of the 4EBP1 protein via the PI3K/AKT pathway. Additionally, the pharmacological inhibition of eIF4E phosphorylation in cervical cancer cell lines substantially reduced the protein levels of CCND1 and ODC1, indicating that E6 of the high-risk genotypes may modify protein synthesis of the eIF4E target genes by increasing the activity of the AKT and ERK pathways.

Identification of a novel germ-line mutation in the TP53 gene in a Mexican family with Li-Fraumeni syndrome.

BACKGROUND: Germ-line mutations of the TP53 gene are known to cause Li-Fraumeni syndrome, an autosomal, dominantly inherited, high-penetrance cancer-predisposition syndrome characterized by the occurrence of a variety of cancers, mainly soft tissue sarcomas, adrenocortical carcinoma, leukemia, breast cancer, and brain tumors. METHODS: Mutation analysis was based on Denaturing high performance liquid chromatography (DHPLC) screening of exons 2-11 of the TP53 gene, sequencing, and cloning of DNA obtained from peripheral blood lymphocytes. RESULTS: We report herein on Li Fraumeni syndrome in a family whose members are carriers of a novel TP53 gene mutation at exon 4. The mutation comprises an insertion/duplication of seven nucleotides affecting codon 110 and generating a new nucleotide sequence and a premature stop codon at position 150. With this mutation, the p53 protein that should be translated lacks the majority of the DNA binding domain. CONCLUSION: To our knowledge, this specific alteration has not been reported previously, but we believe it is the cause of the Li-Fraumeni syndrome in this family.

Molecular epidemiology of bacterial vaginosis and its association with genital micro-organisms in asymptomatic women.

Introduction. Bacterial vaginosis (BV) is dysbiosis associated with an increased risk of several sexually transmitted infections. It is primarily diagnosed via Gram staining, although molecular analyses have presented higher diagnostic accuracy.Aim. This study aimed to evaluate the molecular epidemiology of BV in asymptomatic women to determine its association with several commensal and pathogenic micro-organisms of the genitalia.Methodology. The prevalence of BV was investigated through semiquantitative assessment of 201 women recruited during their routine gynaecological inspection at an outpatient clinic in Tabasco, Mexico.Results. Women with BV showed an increased prevalence of Chlamydia trachomatis (P=0.021) and Mycoplasma hominis (P=0.001). Of the BV-associated micro-organisms, Gardnerella vaginalis was significantly associated with C. trachomatis (P=0.005) and/or Ureaplasma parvum (P=0.003), whereas Atopobium vaginae and Megasphaera type 1 correlated significantly with Mycoplasma hominis (P=0.001). No significant association was observed between human papillomavirus (HPV) infection and BV, although there was increased prevalence of HPV59, HPV73, HPV52 and HPV58 in women displaying cervical cytological abnormalities.Conclusion. Identification of BV-associated micro-organisms via molecular analysis may help to distinguish recurrent cases from new infections and identify micro-organisms potentially associated with pharmacological resistance.

Valproic acid as epigenetic cancer drug: preclinical, clinical and transcriptional effects on solid tumors.

Among many anticancer drugs collectively named "targeted or molecular therapies" epigenetic drugs are clearly promising. Differently from other agents targeting a single gene product, epigenetic drugs have chromatin as their target through inhibition of histone deacetylases (HDACs) and DNA methyltransferases (DNMTs) therefore, yet unspecific, they may act upon most or all tumor types, as deregulation of the methylation and deacetylation machinery are a common hallmark of neoplasia. In the last years, valproic acid (VPA) as emerged as a promising drug for cancer treatment. VPA has shown potent antitumor effects in a variety of in vitro and in vivo systems, and encouraging results in early clinical trials either alone or in combination with demethylating and/or cytotoxic agents. In addition, whole genome expression by microarray analysis from the primary tumors of patients treated with VPA show significant up-regulation of hundred of genes belonging to multiple pathways including ribosomal proteins, oxidative phosphorylation, MAPK signaling; focal adhesion, cell cycle, antigen processing and presentation, proteasome, apoptosis, PI3K, Wnt signaling, calcium signaling, TGF-beta signaling, and ubiquitin-mediated proteolysis among others. Despite in general, industry is not particularly interested in funding the clinical development of VPA, -at least in comparison to novel HDAC inhibitors-, existing preclinical and preliminary clinical data strongly suggest that VPA could be a drug that eventually will be used in combination therapies, either with classical cytotoxics, other molecular-targeted drugs or radiation in a number of solid tumors.

Leptin Modifies the Rat Heart Performance Associated with Mitochondrial Dysfunction Independently of Its Prohypertrophic Effects.

BACKGROUND: Functional receptors for leptin were described on the surface of cardiomyocytes, and there was a prohypertrophic effect with high concentrations of the cytokine. Therefore, leptin could be a link between obesity and the prevalence of cardiovascular diseases. On the other hand, a deleterious effect of leptin on mitochondrial performance was described, which was also associated with the evolution of cardiac hypertrophy to heart failure. The goal of our study was to analyze the effect of the exposure of rat hearts to a high concentration of leptin on cardiac and mitochondrial function. METHODS: Rat hearts were perfused continuously with or without 3.1 nM leptin for 1, 2, 3, or 4 hours. Homogenates and mitochondria were prepared by centrifugation and analyzed for cardiac actin, STAT3, and pSTAT3 by Western blotting, as well as for mitochondrial oxidative phosphorylation, membrane potential, swelling, calcium transport, and content of oxidized lipids. RESULTS: In our results, leptin induced an increased rate-pressure product as a result of increased heart rate and contraction force, as well oxidative stress. In addition, mitochondrial dysfunction expressed as a loss of membrane potential, decreased ability for calcium transport and retention, faster swelling, and less respiratory control was observed. CONCLUSIONS: Our results support the role of leptin as a deleterious factor for cardiac function and indicates that mitochondrial dysfunction could be a trigger for cardiac hypertrophy and failure.

The effects of DNA methylation and histone deacetylase inhibitors on human papillomavirus early gene expression in cervical cancer, an in vitro and clinical study.

BACKGROUND: The methylation status at the human papilloma virus (HPV) genome found in pre-invasive and invasive cervical lesions suggests that neoplastic transformation can be suppressed by gene hypermethylation, whereas hypomethylation accompanies or causes cancer progression; hence, epigenetic therapy aimed at reactivating cellular suppressor-gene expression has the potential to act as a tumor promoter by enhancing HPV oncoprotein expression in HPV-related malignancies. The objective of this study was to determine the influence of hydralazine and valproate on HPV oncogene expression in cervical cancer cell lines and the primary tumors of patients undergoing treatment with hydralazine and valproate. RESULTS: Overall, hydralazine and valproate either alone or combined exerted a growth inhibitory effect on cervical cancer cell lines. A cell line-specific up-regulating effect was observed on E6/E7 gene expression, which in general correlated with DNA hypomethylation and histone acetylation at the long control region (LCR). Nonetheless, E6/E7 expression was unchanged or decreased in the majority of patients with cervical cancer treated with hydralazine, valproate, or both. In some cervical cancer cell lines, these drugs led to increased transcription of p53, and increased its stabilization due to acetylation at lysines 273 and 282, which allowed a higher bax-protein transactivating effect. CONCLUSION: The results of this study demonstrate that hydralazine and valproate can be safely administered to HPV-related malignancies such as cervical cancer because they do not increase viral oncoprotein expression. Most importantly, the antitumor effect of hydralazine and valproate in cervical cancer may at least partially depend on an up-regulating effect on p53 gene and on the valproate-induced hyperacetylation of p53 protein, protecting it from degradation by E6.

Up-regulation of HLA class-I antigen expression and antigen-specific CTL response in cervical cancer cells by the demethylating agent hydralazine and the histone deacetylase inhibitor valproic acid.

BACKGROUND: DNA hypermethylation and histone deacetylation are epigenetic events that contribute to the absence or downregulated expression of different components of the tumor recognition complex. These events affect the processing and presentation of antigenic peptides to CTLs by HLA class-I molecules. In this work evaluated the effect of the DNA hypomethylating agent hydralazine and the histone deacetylase inhibitor valproic acid, on the expression of HLA class-I molecules and on the antigen-specific immune recognition of cervical cancer cells. METHODS: Cell lines C33A (HPV-), CaSki (HPV-16+) and MS751 (HPV-18+) were treated with hydralazine and valproic acid to assess the expression of HLA class-I molecules by flow cytometry and RT-PCR. Promoter methylation of HLA class-I -A, -B and C, was also evaluated by Methylation-Specific PCR. Primary cervical tumors of four HLA-A*0201 allele patients were typed for HPV and their CTL's stimulated in vitro with the T2 cell line previously loaded with 50 microM of the HPV peptides. Cytotoxicity of stimulated CTL's was assayed against Caski and MS751 cells pre-treated with hydralazine and valproic acid. RESULTS: Valproic acid and hydralazine/valproic acid up-regulated the constitutive HLA class-I expression as evaluated by flow cytometry and RT-PCR despite constitutive promoter demethylation at these loci. Hydralazine and valproic acid in combination but no IFN-gamma hyperacetylated histone H4 as evaluated by ChiP assay. The antigenic immune recognition of CaSki and MS751 cells by CTLs specific to HPV-16/18 E6 and E7-derived epitopes, was increased by VA and H/VA and the combination of H/VA/IFN-gamma. CONCLUSION: These results support the potential use of hydralazine and valproic acid as an adjuvant for immune intervention in cervical cancer patients whenever clinical protocols based on tumor antigen recognition is desirable, like in those cases where the application of E6 and E7 based therapeutic vaccines is used.

[Toward cervical cancer prevention: strategies employed in the development of HPV vaccines]. / Hacia la prevención del cáncer cérvico-uterino: estrategias empleadas en el desarrollo de vacunas contra el VPH.

An HPV persistent infection is doubtless the main factor involved in cervical cancer development. It is clear that the majority of HPV infections are self-limited and not all high-risk HPV infections are destined to progress to a higher grade lesion. Due to viral mechanisms that evade the immune system, in some cases the immune response against HPV is not as effective, allowing the establishment of persistent infections. The promise of a vaccine that can avoid HPV infections and therefore decrease cervical cancer incidence, has been motive of great interest and enthusiasm on the search of different strategies for obtaining an effective vaccine. At present, several prophylactic vaccines have been developed based in virus like particles (VLPs) produced with L1 viral proteins. Results of these vaccines applied to women between 16 and 23 years old show high tolerability and immunogenicity with higher antibody titers than those seen in an HPV natural infection. Even these vaccines can not wholly prevent infections caused by HPV types included in the vaccine design; its efficacy has been demonstrated for their ability to eliminate HPV persistent infections and to prevent the development of cervical intraepithelial neoplasia. These vaccines are currently in phase III of clinical trials, whose results will determine its impact in the general population. Therapeutic vaccines are focused in the elimination of established cervical lesions; nevertheless their efficacy has not been proved for clinical use.