RESUMEN

Background and Objectives: REST (RE1-silencing transcription factor) diminution is associated with transcriptional relaxation, neuropeptide overexpression, and phenotype redefinition in neuroendocrine cancers, but this effect has barely been studied in cervical cancer (CC). We previously reported reduced expressions of REST in samples with premalignant lesions and CC; however, the transcriptional consequences for neural genes associated with reduced REST expression in CC are unknown. Therefore, the objective of this work was to evaluate the expression of neuronal genes in cancerous cells with reduced expression levels of REST. Materials and Methods: Here, we monitored levels of REST by immunostaining along the premalignant lesions and in invasive cervical squamous cell carcinoma (SCC) and endocervical adenocarcinoma (ADC) in tissue samples from female patients from southern Mexico and the derivative cell lines SiHa and HeLa, respectively. Next, we selected REST target genes in silico and explored the effect of REST silencing by RT-PCR in siRNA-treated HeLa cells. Results: The results show a REST diminution in premalignant lesions, SCC, ADC, and cancerous cell lines. Further REST silencing in HeLa cells altered the expression of genes containing the RE1 (Restrictive Element 1) sequence, including CgA (chromogranin A), CHRNß2 (cholinergic receptor nicotinic ß 2 subunit), BDNF (brain-derived neurotrophic factor), CRF (corticotropin-releasing factor), and RASSF1A (Ras association domain family 1). Conclusions: This work provides preliminary evidence of the role of REST loss in the transcriptional regulation of its target genes in HeLa cells, which could have positive implications for the search for new biomarkers of cervical cancer.

Asunto(s)

Proteínas Represoras , Factores de Transcripción , Neoplasias del Cuello Uterino , Femenino , Humanos , Biomarcadores , Expresión Génica , Células HeLa , ARN Interferente Pequeño , Factores de Transcripción/genética , Neoplasias del Cuello Uterino/genética , Proteínas Represoras/genética

RESUMEN

In Mexico, for the past 30 years, a continuous decrease in the incidence of clinical taeniosis/cysticercosis has been documented. This work aimed to determine the influence of improvement in socioeconomic conditions on the prevalence of Taenia solium in four endemic communities in northwestern Mexico. This study was carried out in two phases. First, documentary information (1989-2018) was collected about the prevalence of Theridion solium in the federal entity of Sinaloa State. Second, a pilot study was performed in four communities of Sinaloa, which had an endemic history of Taenia transmission. In each community, a risk factor questionnaire was applied, and serum and stool samples were collected for convenience in a non-probabilistic way. Anti-cysticercus antibodies and adult worm coproantigen were determined. The documentary analysis showed the incidence of taeniosis and cysticercosis to have decreased by 98 and 53%, respectively, while the human development index increased by 5% (1992-2017). Our data suggest that the risk of parasitic transmission is low, although female sex was a risk factor for reporting tremors or seizures (prevalence rate 2.1336, CI: 1.1821-3.8508) and background of tapeworm infection (prevalence rate 1.2893, CI: 0.9795-1.6972). No tapeworms or eggs were found while examining stool samples, but protozoa cysts were observed in four samples. Unexpectedly, only one of the 79 stool samples was positive for coproantigens. This positive result was confirmed in a second sample. However, the evaluation of a third sample was negative. No antibodies were found in human (n = 377) or pig (n = 69) samples. These data suggest parasite transmission has been interrupted and could be possibly associated with improving socioeconomic conditions. Further studies are needed to determine the real prevalence of zoonoses in Mexico.

Asunto(s)

Cisticercosis , Enfermedades de los Porcinos , Taenia solium , Teniasis , Femenino , Humanos , Porcinos , Animales , Prevalencia , México/epidemiología , Proyectos Piloto , Óvulo , Cisticercosis/epidemiología , Cisticercosis/parasitología , Cisticercosis/veterinaria , Teniasis/epidemiología , Teniasis/parasitología , Teniasis/veterinaria , Enfermedades de los Porcinos/epidemiología , Factores Socioeconómicos

RESUMEN

Localized cutaneous leishmaniasis (LCL) is an endemic disease in several Mexican States with the main endemic areas located in the South-Southeast region of the country, where 90% of Leishmania (Leishmania) mexicana cases are registered. The Southeast region is located in the Yucatan Peninsula, including Campeche, Quintana Roo and Yucatan States. Campeche and Quintana Roo register more than 60% of the cases in the country each year, while in Yucatan the reports are of imported cases due to residents traveling to endemic areas. However, since 2015, autochthonous cases have been diagnosed by health authorities in municipalities with no previous transmission records. We aimed to identify Leishmania parasite species involved in autochthonous cases by means of the PCR technique. The present study included 13 autochthonous cases of LCL with clinical and parasitological diagnoses during 2018 and 2019 by health authorities, without specific identification of the causal agent. Tissue samples were taken by scraping the margins of active lesions and then they were spotted onto an FTATM Elute Microcard. Next, DNA was eluted and used for PCR amplification of specific Leishmania genus and L. (L.) mexicana species-specific fragments. Molecular analysis showed evidence that L. (L.) mexicana was the causal agent of LCL in 12 of the 13 patients; in one patient, PCR was not performed due to the patient's refusal to participate in the study. Identifying Leishmania species that cause LCL is necessary to define efficient treatment schemes and control strategies for the disease in vulnerable and susceptible areas of the Yucatan State's municipalities.

Asunto(s)

Leishmania mexicana , Leishmania , Leishmaniasis Cutánea , Enfermedades Endémicas , Humanos , Leishmania mexicana/genética , Leishmaniasis Cutánea/diagnóstico , Leishmaniasis Cutánea/epidemiología , Leishmaniasis Cutánea/parasitología , México/epidemiología

RESUMEN

ABSTRACT Localized cutaneous leishmaniasis (LCL) is an endemic disease in several Mexican States with the main endemic areas located in the South-Southeast region of the country, where 90% of Leishmania (Leishmania) mexicana cases are registered. The Southeast region is located in the Yucatan Peninsula, including Campeche, Quintana Roo and Yucatan States. Campeche and Quintana Roo register more than 60% of the cases in the country each year, while in Yucatan the reports are of imported cases due to residents traveling to endemic areas. However, since 2015, autochthonous cases have been diagnosed by health authorities in municipalities with no previous transmission records. We aimed to identify Leishmania parasite species involved in autochthonous cases by means of the PCR technique. The present study included 13 autochthonous cases of LCL with clinical and parasitological diagnoses during 2018 and 2019 by health authorities, without specific identification of the causal agent. Tissue samples were taken by scraping the margins of active lesions and then they were spotted onto an FTATM Elute Microcard. Next, DNA was eluted and used for PCR amplification of specific Leishmania genus and L. (L.) mexicana species-specific fragments. Molecular analysis showed evidence that L. (L.) mexicana was the causal agent of LCL in 12 of the 13 patients; in one patient, PCR was not performed due to the patient's refusal to participate in the study. Identifying Leishmania species that cause LCL is necessary to define efficient treatment schemes and control strategies for the disease in vulnerable and susceptible areas of the Yucatan State's municipalities.

RESUMEN

Hepatitis C virus (HCV) infection represents an important public health problem worldwide. Reduction of HCV morbidity and mortality is a current challenge owned to several viral and host factors. Virus molecular evolution plays an important role in HCV transmission, disease progression and therapy outcome. The high degree of genetic heterogeneity characteristic of HCV is a key element for the rapid adaptation of the intrahost viral population to different selection pressures (e.g., host immune responses and antiviral therapy). HCV molecular evolution is shaped by different mechanisms including a high mutation rate, genetic bottlenecks, genetic drift, recombination, temporal variations and compartmentalization. These evolutionary processes constantly rearrange the composition of the HCV intrahost population in a staging manner. Remarkable advances in the understanding of the molecular mechanism controlling HCV replication have facilitated the development of a plethora of direct-acting antiviral agents against HCV. As a result, superior sustained viral responses have been attained. The rapidly evolving field of anti-HCV therapy is expected to broad its landscape even further with newer, more potent antivirals, bringing us one step closer to the interferon-free era.

Asunto(s)

Antivirales/uso terapéutico , Evolución Molecular , Hepacivirus/efectos de los fármacos , Hepacivirus/genética , Hepatitis C/tratamiento farmacológico , Hepatitis C/transmisión , Animales , Antivirales/efectos adversos , Progresión de la Enfermedad , Farmacorresistencia Viral , Quimioterapia Combinada , Genotipo , Hepacivirus/patogenicidad , Hepatitis C/diagnóstico , Interacciones Huésped-Patógeno , Humanos , Fenotipo , Resultado del Tratamiento

RESUMEN

Globally, hepatitis C virus (HCV) infection affects approximately 130 million people and 3 million new infections occur annually. HCV is also recognized as an important cause of chronic liver disease in children. The absence of proofreading properties of the HCV RNA polymerase leads to a highly error prone replication process, allowing HCV to escape host immune response. The adaptive nature of HCV evolution dictates the outcome of the disease in many ways. Here, we investigated the molecular evolution of HCV in three unrelated children who acquired chronic HCV infection as a result of mother-to-child transmission, two of whom were also coinfected with HIV-1. The persistence of discrete HCV variants and their population structure were assessed using median joining network and Bayesian approaches. While patterns of viral evolution clearly differed between subjects, immune system dysfunction related to HIV coinfection or persistent HCV seronegativity stand as potential mechanisms to explain the lack of molecular evolution observed in these three cases. In contrast, treatment of HCV infection with PegIFN, which did not lead to sustained virologic responses in all 3 cases, was not associated with commensurate variations in the complexity of the variant spectrum. Finally, the differences in the degree of divergence suggest that the mode of transmission of the virus was not the main factor driving viral evolution.

Asunto(s)

Hepacivirus/efectos de los fármacos , Hepatitis C Crónica/transmisión , Transmisión Vertical de Enfermedad Infecciosa , Complicaciones Infecciosas del Embarazo/tratamiento farmacológico , Antivirales/uso terapéutico , Niño , Coinfección/virología , Evolución Molecular , Femenino , Variación Genética , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/transmisión , Infecciones por VIH/virología , Seropositividad para VIH/tratamiento farmacológico , Seropositividad para VIH/transmisión , VIH-1 , Hepacivirus/genética , Hepatitis C Crónica/tratamiento farmacológico , Hepatitis C Crónica/virología , Humanos , Interferón alfa-2 , Interferón-alfa/uso terapéutico , Masculino , Polietilenglicoles/uso terapéutico , Embarazo , Complicaciones Infecciosas del Embarazo/virología , ARN Viral , Proteínas Recombinantes/uso terapéutico , Ribavirina/uso terapéutico , Resultado del Tratamiento

RESUMEN

Here, we analyze the viral divergence among hepatitis C virus (HCV) chronic cases infected with genotype 1. The intrahost viral evolution was assessed by deep sequencing using the 454 Genome Sequencer platform. The results showed a rapid nucleotide sequence divergence. This notorious short-term viral evolution is of the utmost importance for the study of HCV transmission, because direct links between related samples were virtually lost. Thus, rapid divergence of HCV significantly affects genetic relatedness studies and outbreak investigations.

Asunto(s)

Variación Genética , Hepacivirus/genética , Hepatitis C Crónica/virología , Adulto , Anciano , Evolución Molecular , Femenino , Genoma Viral , Genotipo , Hepacivirus/clasificación , Hepatitis C Crónica/genética , Humanos , Interferones , Interleucinas/genética , Masculino , Persona de Mediana Edad , Filogenia , Factores de Riesgo , Análisis de Secuencia de ADN

RESUMEN

Here, we describe a transmission event of hepatitis C virus (HCV) among injection drug users. Next-generation sequencing (NGS) was used to assess the intrahost viral genetic variation. Deep amplicon sequencing of HCV hypervariable region 1 allowed for a detailed analysis of the structure of the viral population. Establishment of the genetic relatedness between cases was accomplished by phylogenetic analysis. NGS is a powerful tool with applications in molecular epidemiology studies and outbreak investigations.

Asunto(s)

Hepacivirus/genética , Hepatitis C/transmisión , Secuenciación de Nucleótidos de Alto Rendimiento , Abuso de Sustancias por Vía Intravenosa/complicaciones , Adulto , Consumidores de Drogas , Hepacivirus/clasificación , Hepatitis C/etiología , Hepatitis C/virología , Humanos , Masculino , Persona de Mediana Edad , Tipificación Molecular , Filogenia , Análisis de Secuencia de ADN , Proteínas no Estructurales Virales/genética , Proteínas Virales/genética

RESUMEN

The use of telaprevir and boceprevir, both protease inhibitors (PI), as part of the specifically targeted antiviral therapy for hepatitis C (STAT-C) has significantly improved sustained virologic response (SVR) rates. However, different clinical studies have also identified several mutations associated with viral resistance to both PIs. In the absence of selective pressure, drug-resistant hepatitis C virus (HCV) mutants are generally present at low frequency, making mutation detection challenging. Here, we describe a mismatch amplification mutation assay (MAMA) PCR method for the specific detection of naturally occurring drug-resistant HCV mutants. MAMA PCR successfully identified the corresponding HCV variants, while conventional methods such as direct sequencing, endpoint limiting dilution (EPLD), and bacterial cloning were not sensitive enough to detect circulating drug-resistant mutants in clinical specimens. Ultradeep pyrosequencing was used to confirm the presence of the corresponding HCV mutants. In treatment-naïve patients, the frequency of all resistant variants was below 1%. Deep amplicon sequencing allowed a detailed analysis of the structure of the viral population among these patients, showing that the evolution of the NS3 is limited to a rather small sequence space. Monitoring of HCV drug resistance before and during treatment is likely to provide important information for management of patients undergoing anti-HCV therapy.

Asunto(s)

Antivirales/farmacología , Farmacorresistencia Viral , Hepacivirus/efectos de los fármacos , Hepatitis C/virología , Mutación , Oligopéptidos/farmacología , Prolina/análogos & derivados , Adulto , Biota , Femenino , Hepacivirus/clasificación , Hepacivirus/genética , Hepacivirus/aislamiento & purificación , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Humanos , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa/métodos , Prolina/farmacología , Virología/métodos

RESUMEN

Dengue virus (DENV) is the most important arthropod-borne viral infection in humans. Here, the genetic relatedness among autochthonous DENV Mexican isolates was assessed. Phylogenetic and median-joining network analyses showed that viral strains recovered from different geographic locations are genetically related and relatively homogeneous, exhibiting limited nucleotide diversity.

Asunto(s)

Virus del Dengue/clasificación , Virus del Dengue/aislamiento & purificación , Dengue/epidemiología , Dengue/virología , Análisis por Conglomerados , Virus del Dengue/genética , Variación Genética , Genotipo , Humanos , México/epidemiología , Epidemiología Molecular , Filogeografía , ARN Viral/genética

RESUMEN

Several studies have identified associations between single nucleotide polymorphisms (SNPs) occurring near the interleukin-28B (IL-28B) gene and response to antiviral treatment among hepatitis C virus (HCV) patients. Here, we describe a reliable melt-mismatch amplification mutation assay (melt-MAMA) PCR-based genotyping method for IL-28B which can be used in the management of HCV patients, helping to better define the course of therapy.

Asunto(s)

Antivirales/administración & dosificación , Hepatitis C Crónica/tratamiento farmacológico , Interleucinas/genética , Mutación , Reacción en Cadena de la Polimerasa/métodos , Polimorfismo de Nucleótido Simple , Temperatura de Transición , Anciano , Femenino , Genotipo , Humanos , Interferones , Masculino , Persona de Mediana Edad , Pronóstico , Resultado del Tratamiento