Bioinformatics Analysis Reveals E6 and E7 of HPV 16 Regulate Metabolic Reprogramming in Cervical Cancer, Head and Neck Cancer, and Colorectal Cancer through the PHD2-VHL-CUL2-ELOC-HIF-1α Axis.

Human papillomavirus 16 (HPV 16) infection is associated with several types of cancer, such as head and neck, cervical, anal, and penile cancer. Its oncogenic potential is due to the ability of the E6 and E7 oncoproteins to promote alterations associated with cell transformation. HPV 16 E6 and E7 oncoproteins increase metabolic reprogramming, one of the hallmarks of cancer, by increasing the stability of hypoxia-induced factor 1 α (HIF-1α) and consequently increasing the expression levels of their target genes. In this report, by bioinformatic analysis, we show the possible effect of HPV 16 oncoproteins E6 and E7 on metabolic reprogramming in cancer through the E6-E7-PHD2-VHL-CUL2-ELOC-HIF-1α axis. We proposed that E6 and E7 interact with VHL, CUL2, and ELOC in forming the E3 ubiquitin ligase complex that ubiquitinates HIF-1α for degradation via the proteasome. Based on the information found in the databases, it is proposed that E6 interacts with VHL by blocking its interaction with HIF-1α. On the other hand, E7 interacts with CUL2 and ELOC, preventing their binding to VHL and RBX1, respectively. Consequently, HIF-1α is stabilized and binds with HIF-1ß to form the active HIF1 complex that binds to hypoxia response elements (HREs), allowing the expression of genes related to energy metabolism. In addition, we suggest an effect of E6 and E7 at the level of PHD2, VHL, CUL2, and ELOC gene expression. Here, we propose some miRNAs targeting PHD2, VHL, CUL2, and ELOC mRNAs. The effect of E6 and E7 may be the non-hydroxylation and non-ubiquitination of HIF-1α, which may regulate metabolic processes involved in metabolic reprogramming in cancer upon stabilization, non-degradation, and translocation to the nucleus.

Characterization of Pulmonary Bacteriobiota in Critically Ill Patients in Southern Peru through Next-Generation Sequencing Technology.

Sequence variation in the 16S gene is widely used to characterize diverse microbial communities. This was the first pilot study carried out in our region where the pulmonary microbiota of critically ill patients was investigated and analyzed, with the aim of finding a specific profile for these patients that can be used as a diagnostic marker. An study of critical patients mechanically ventilated for non-respiratory indications, in a polyvalent intensive care unit, was carried out; samplee were extracted by endotracheal aspiration and subsequently the microbiota was characterized through Next-Generation Sequencing Technology (NGS). The predominant phyla among the critically ill patients were Proteobacteria, Firmicutes and Bacteroidata. In the surviving patients group, the predominant phyla were Proteobacteria, Bacteroidata and Firmicutes, in the group of deceased patients thy were Firmicutes, Proteobacteria, and Bacteroidata. We found a decrease in commensal bacteria in deceased patients and a progressive increase in in-hospital germs.

Evaluación de los patrones de farmacorresistencia de mycobacterium tuberculosis en un hospital público de Lima, Perú durante 2022

Antecedentes: La tuberculosis es un problema de salud pública considerado la principal causa mundial de muerte por una enfermedad infecciosa entre los adultos. El diagnóstico suele ser difícil y se basa en hallazgos clínicos, epidemiológicos, radiológicos, bacteriológicos, histológicos y bioquímicos. El diagnóstico oportuno, la identificación del perfil de susceptibilidad y el cumplimiento del seguimiento son importantes para permitir un tratamiento más eficaz y evitar formas graves de la enfermedad. Objetivo: Describir los patrones de resistencia de Mycobacterium tuberculosis identificados en el periodo del año 2022 en el Hospital María Auxiliadora. Material y métodos: Se trata de un estudio observacional, transversal, de pacientes diagnosticados de tuberculosis durante todo el año 2022 en el Centro de Excelencia en Tuberculosis (COE-TB), división del servicio de medicina respiratoria del Hospital María Auxiliadora, Lima, Perú. Los datos fueron recolectados de las historias clínicas que luego fueron incluidas para el análisis estadístico. Las características clínicas y demográficas se describieron mediante frecuencias absolutas y porcentajes. Para evaluar la asociación entre el perfil de sensibilidad de la tuberculosis y las variables independientes se utilizó la prueba de Chi cuadrado y la prueba exacta de Fisher. Un valor p < 0,05 se consideró estadísticamente significativo. Resultados: Se incluyeron en el presente estudio 261 historias clínicas. El grupo de edad más frecuente fue el de 17-59 años, la mayoría eran varones (62,1%) y el 15,7% eran recidivantes, según lo establecido en la norma técnica nacional. Del total, el 89,7% eran sensibles a fármacos de primera línea; el 6,1% de los pacientes eran multirresistentes (MDR), y el 0,8% presentaban resistencia extensiva a fármacos (XDR); asimismo, el 0,8% y el 2,7% presentaban resistencia sólo para rifampicina y resistencia sólo para isoniazida respectivamente. La infección por VIH se detectó en el 14,2%. La forma más frecuente de tuberculosis fue la pulmonar (49%), seguida de la tuberculosis pleural (21,8%). Conclusiones: La tuberculosis es una afección mundial cuyos patrones de farmacorresistencia continúan evolucionando. Sin embargo, en nuestro hospital, un centro de referencia del sur del Perú, la mayoría de los pacientes con TB siguen siendo sensibles a los fármacos de primera línea. Sólo se encontró una pequeña cantidad de pacientes MDR y XDR. Además, la presentación clínica más frecuente fue la tuberculosis pulmonar seguida de la pleural.

Background: Tuberculosis is a public health problem considered to be the world's leading cause of death from an infectious disease among adults. Diagnosis is often challenging and is based on clinical, epidemiological, radiological, bacteriological, histological and biochemical findings. Timely diagnosis, identification of the susceptibility profile and follow-up compliance is important to enable more effective treatment and avoid severe forms of the disease. Objective: Describe the resistance patterns of Mycobacterium tuberculosis identified in the period of the year 2022 at Hospital María Auxiliadora. Material and Methods: This is an observational, cross-sectional study of patients diagnosed with tuberculosis throughout the year 2022 in the Tuberculosis Center of Excellence (TB COE), division of the respiratory medicine department at the Hospital Maria Auxiliadora, Lima, Peru. Data was collected from the medical records which was then included for the statistical analysis. The clinical and demographic characteristics were described by absolute frequencies and percentages. Chi-square test and Fisher's exact test were used to evaluate the association between the sensitivity profile of tuberculosis and the independent variables. A p-value < 0.05 was considered as statistically significant. Results: A total of 261 medical records were included in the present study. The most frequent age group was 17-59 years old, the majority were male (62.1%) and 15.7% were relapses, as established on national technical standard. Of the total, 89.7% were sensitive to first line drugs; 6.1% of the patients were multidrug-resistant (MDR), and 0.8% presented extensively drug-resistance (XDR); likewise, 0.8% and 2.7% presented resistance for rifampicin only and resistance for isoniazid only respectively. HIV infection was found at 14.2%. The most common form of tuberculosis was pulmonary (49%) followed by pleural tuberculosis (21.8%). Conclusion: Tuberculosis is a worldwide condition whose drug-resistance patterns continue evolving. However, in our hospital, a southern Peru reference Center, most TB patients are still sensitive to first line drugs. Only a small amount of MDR and XDR patients were found. Moreover, the most common clinical presentation was pulmonary followed by pleural tuberculosis.

Engineering highly thermostable Cas12b via de novo structural analyses for one-pot detection of nucleic acids.

CRISPR-Cas-based diagnostics have the potential to elevate nucleic acid detection. CRISPR-Cas systems can be combined with a pre-amplification step in a one-pot reaction to simplify the workflow and reduce carryover contamination. Here, we report an engineered Cas12b with improved thermostability that falls within the optimal temperature range (60°C-65°C) of reverse transcription-loop-mediated isothermal amplification (RT-LAMP). Using de novo structural analyses, we introduce mutations to wild-type BrCas12b to tighten its hydrophobic cores, thereby enhancing thermostability. The one-pot detection assay utilizing the engineered BrCas12b, called SPLENDID (single-pot LAMP-mediated engineered BrCas12b for nucleic acid detection of infectious diseases), exhibits robust trans-cleavage activity up to 67°C in a one-pot setting. We validate SPLENDID clinically in 80 serum samples for hepatitis C virus (HCV) and 66 saliva samples for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with high specificity and accuracy. We obtain results in as little as 20 min, and with the extraction process, the entire assay can be performed within an hour.

The NRSF/REST transcription factor in hallmarks of cancer: From molecular mechanisms to clinical relevance.

The RE-1 silencing transcription factor (REST), or neuron restrictive silencing factor (NRSF), was first identified as a repressor of neuronal genes in non-neuronal tissue. Interestingly, this transcription factor may act as a tumor suppressor or an oncogenic role in developing neuroendocrine and other tumors in patients. The hallmarks of cancer include six biological processes, including proliferative signaling, evasion of growth suppressors, resistance to cell death, replicative immortality, inducing angiogenesis, and activating invasion and metastasis. In addition to two emerging hallmarks, the reprogramming of energy metabolism and evasion of the immune response are all implicated in the development of human tumors. It is essential to know the role of these processes as they will affect the outcome of alternatives for cancer treatment. Various studies in this review demonstrate that NRSF/REST affects the different hallmarks of cancer that could position NRSF/REST as an essential target in the therapy and diagnosis of certain types of cancer.

The expression of Oct3/4A mRNA and not its isoforms is upregulated by the HPV16 E7 oncoprotein.

PURPOSE: Oct3/4 a transcription factor is involved in maintaining the characteristics of cancer stem cells. Oct3/4 can be expressed differentially with respect to the progression of cervical cancer (CC). In addition, Oct3/4 can give rise to three isoforms by alternative splicing of the mRNA Oct3/4A, Oct3/4B and Oct3/4B1. The aim of this study was to evaluate the mRNA expression from Oct3/4A, Oct3/4B and Oct3/4B1 in low-grade squamous intraepithelial lesion (LSIL), high-grade squamous intraepithelial lesion (HSIL), CC samples, and measure the effect of the HPV16 E7 oncoprotein on the mRNA expression from Oct3/4 isoforms in the C-33A cell line. METHODS: The expression levels of Oct3/4A, Oct3/4B and Oct3/4B1 mRNA were analyzed by reverse transcription quantitative polymerase chain reaction (RT-qPCR) in patients with LSILs, HSILs and CC. Additionally, C-33A cells that expressed the HPV16 E7 oncoprotein were established to evaluate the effect of E7 on the expression of Oct3/4 mRNA isoforms. RESULTS: Oct3/4A (p = 0.02), Oct3/4B (p = 0. 001) and Oct3/4B1 (p < 0. 0001) expression is significantly higher in patients with LSIL, HSIL and CC than in woman with non-IL. In the C-33A cell line, the expression of Oct3/4A mRNA in the presence of the E7 oncoprotein increased compared to that in nontransfected C-33A cells. CONCLUSION: Oct3/4B and Oct3/4B1 mRNA were expressed at similar levels among the different groups. These data indicate that only the mRNA of Oct3/4A is upregulated by the HPV16 E7 oncoprotein.

Anemia in pregnant women residing at different geographical altitudes in Arequipa, Peru / Anemia en gestantes residentes en diferentes altitudes geográficas de Arequipa, Perú

Purpose: To identify the frequency of anemia in pregnant women at different geographical altitudes in the Arequipa region of Peru. Methods: A quantitative, descriptive, and retrospective study was carried out. The study population consisted of 35,725 pregnant women living in the Arequipa Region at different altitudes. Data on age, gestational age, weight, height, province of residence, altitude, hemoglobin were collected. Results: Using World Health Organization altitude adjusted hemoglobin values, anemia prevalence in pregnant women between 2018-2019 was 13.7 percent in the Arequipa Region, while using unadjusted hemoglobin, the overall prevalence was 4.1 percent. When analyzed by altitudes, the frequency of anemia was 9.77 percent below 1 000 m 13.1 percent between 1 000-1 999 m, 13.1 percent between 2.000-2.999 m, 31.5 percent between 3.000-3.999 and 47.1 percent between 4.000-4.999. Nevertheless, when using unadjusted hemoglobin values rates were 6.67 percent for the 1.000-1.999 range, 2.39 percent for ranges between 2.000-2.999 m and 3.000-3.999 m, and 5.19 percent for altitudes above 4.000 m. Conclusions: There is a directly proportional correlation in the prevalence of anemia in pregnant women and higher altitude (p<0.01) as well as levels of anemia during the last trimester of pregnancy. Adjusting the hemoglobin values by altitude results in triple the prevalence of anemia. A throughout revision of the suitability of current guidelines to diagnose and prevent anemia at high altitude is recommended (AU)

Objetivo: Identificar la frecuencia de anemia en gestantes de diferentes altitudes geográficas en la región Arequipa, Perú. Métodos: Se realizó un estudio cuantitativo, descriptivo y retrospectivo. La población de estudio estuvo constituida por 35 725 gestantes residentes en la Región Arequipa a diferentes altitudes. Se recogieron datos de edad, edad gestacional, peso, talla, provincia de residencia, altitud, hemoglobina. Resultados: Utilizando los valores de hemoglobina ajustados por altitud de la Organización Mundial de la Salud, la prevalencia de anemia en gestantes entre 2018-2019 fue de 13,7 por ciento en la Región Arequipa, mientras que utilizando la hemoglobina no ajustada, la prevalencia global fue de 4,1 por ciento. Al analizar por altitudes, la frecuencia de anemia fue de 9,77 por ciento por debajo de 1 000 m 13,1 por ciento entre 1 000-1 999 m, 13,1 por ciento entre 2 000-2 999 m, 31,5 por ciento entre 3 000-3 999 y 47,1 por ciento entre 4 000-4 999. Sin embargo, cuando se utilizaron valores de hemoglobina no ajustados, las tasas fueron del 6,67 por ciento para el intervalo de 1 000-1 999, del 2,39 por ciento para los intervalos entre 2 000-2 999 m y 3 000-3 999 m, y del 5,19 por ciento para altitudes superiores a 4 000 m. Conclusiones: Existe una correlación directamente proporcional en la prevalencia de anemia en embarazadas y mayor altitud (p<0,01), así como niveles de anemia durante el último trimestre del embarazo. Ajustando los valores de hemoglobina por la altitud se triplica la prevalencia de anemia. Se recomienda una revisión en profundidad de la idoneidad de las directrices actuales para diagnosticar y prevenir la anemia a gran altitud(AU)

TET Enzymes and 5hmC Levels in Carcinogenesis and Progression of Breast Cancer: Potential Therapeutic Targets.

Breast Cancer (BC) was the most common female cancer in incidence and mortality worldwide in 2020. Similarly, BC was the top female cancer in the USA in 2022. Risk factors include earlier age at menarche, oral contraceptive use, hormone replacement therapy, high body mass index, and mutations in BRCA1/2 genes, among others. BC is classified into Luminal A, Luminal B, HER2-like, and Basal-like subtypes. These BC subtypes present differences in gene expression signatures, which can impact clinical behavior, treatment response, aggressiveness, metastasis, and survival of patients. Therefore, it is necessary to understand the epigenetic molecular mechanism of transcriptional regulation in BC, such as DNA demethylation. Ten-Eleven Translocation (TET) enzymes catalyze the oxidation of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC) on DNA, which in turn inhibits or promotes the gene expression. Interestingly, the expression of TET enzymes as well as the levels of the 5hmC epigenetic mark are altered in several types of human cancers, including BC. Several studies have demonstrated that TET enzymes and 5hmC play a key role in the regulation of gene expression in BC, directly (dependent or independent of DNA de-methylation) or indirectly (via interaction with other proteins such as transcription factors). In this review, we describe our recent understanding of the regulatory and physiological function of the TET enzymes, as well as their potential role as biomarkers in BC biology.

Determination of Sarcocystis lamacanis microcysts in the cardiac muscle of alpacas (Vicugna pacos) and their correlation with troponin cTnI. A study performed in the high Andean region of southern Peru.

The breeding of alpaca (Vicugna pacos) is one of the most important economic activities in the high Andean areas of Peru. The commercialization of products derived from alpaca represents more than 80% of the income of high-Andean families. However, the infestation of parasites such as Sarcocystis lamacanis in the alpacas causes economic losses that deteriorate the already diminished quality of life of the alpaca breeder. The search for biomarkers that allow the early detection of these parasites is one of the most critical challenges in Peru, a country with the largest population of alpacas worldwide. This work aimed to analyze and quantify the microcysts formed by the parasite and relate them to the troponin cTnI level in the blood serum. Troponins are proteins secreted when there is damage to the cardiac muscle. 60 blood and cardiac tissue samples were collected from Tisco and La Raya slaughterhouses, localities of Caylloma Province in Arequipa, and Chucuito District in Puno, both regions in southern Peru. The cardiac muscle samples were processed with the routine histology technique and stained with hematoxylin and eosin. In addition, serum samples were processed with the ELISA and immunochromatography methods for troponin cTnI. Results were 100% positive for the presence of Sarcocystis lamacanis microcysts in all cardiac muscle samples. The average microcyst quantification per field of 100x were 3.5 and 5.7 for the Tisco and La Raya samples. In addition, several microscopic lesions were observed in the cardiac muscles: microcyst infiltration between muscle fibers, basophilic microcysts with a thick outer membrane and bradyzoites inside, and tissue displacement. On the other hand, all serum blood samples were negative for troponin cTnI, with both methods, ELISA and immunochromatography. For results, we infer troponin cTnI do not can be used as a biomarker for heart damage caused by Sarcocystis lamacanis parasite in alpacas.

Intestinal Microbiota in Children with Anemia in Southern Peru through Next-Generation Sequencing Technology.

Knowledge of the sequencing of the 16S rRNA gene constitutes a true revolution in understanding the composition of the intestinal microbiota and its implication in health states. This study details microbial composition through next-generation sequencing (NGS) technology in children with anemia. Anemia is the most frequent hematological disorder that affects human beings. In Peru, it is one of the conditions that presents the most significant concern due to the adverse effects that cause it, such as delayed growth and psychomotor development, in addition to a deficiency in cognitive development.

Integrated bioinformatics analysis reveals that EZH2-rich domains promote transcriptional repression in cervical cancer.

Cervical cancer is the third female cancer most common worldwide. The carcinogenic process involves an alteration of the mechanisms associated with transcription. Several studies have reported an oncogenic role of the polycomb complex subunit, EZH2. However, the role of EZH2 in cervical cancer is unknown. Hence, the objective of this study was to determine the role of EZH2 in transcriptional regulation in cervical cancer. The EZH2 expression and the methylation status of its promoter were analyzed in The Cancer Genome Atlas. The EZH2 enrichment profile was analyzed using chromatin immunoprecipitation with massively parallel DNA sequencing data provided by ENCODE project. The chromatin compartments were identified in the 4D Nucleome Data Portal. The functional annotation was examined in Enrichr. We report that EZH2 expression is increased in cervical cancer which is associated with hypomethylation of its promoter. EZH2 is enriched at promoter and distal intergenic regions. We identified that EZH2 defines chromatin domains enriched with H3K27me3 within repressive compartments in the HeLa-S3 cell line. Additionally, high EZH2 expression is associated with the repression of the senescent phenotype in cervical cancer patients. Our results suggest the participation of EZH2 in the generation of domains with a silencer function in cervical cancer, which regulate the expression of genes associated with cellular senescence.

[Reinsertion to the work in workers with partially permanent disability for hand injury]. / Reinserción laboral en trabajadores con incapacidad permanente parcial por lesiones de mano.

Background: Hand injuries resulting from accidents at work are one of the main causes of disability in workers. Every worker ruled with Partial Permanent Disability must legally be reinstated to the same workplace. Objective: To know the prevalence of reintegration and causes of non-reintegration into workers with Partial Permanent Disability due to hand injuries. Material and methods: A descriptive, observational, and retrospective study, which included 100% of the opinions of Parcial Permanent Disability due to hand injuries, generated from 2012 to 2016 at UMF 61 of Veracruz. Results: 143 cases were analyzed, 127 (88.8%) were men and 16 (11.2%) women, with a mean age of 37.3 ± 11.6 years. Labor reintegration in the same company occurred in 60 (42%) of the cases, 50 (35%) were reinstated in another company and 33 (23.1%) were not reinstated to work. Regarding work termination: 51 (35.7%) workers were laid off after their ruling, 13 (9.1%) resigned, 12 (8.4%) terminated their contract, and 7 (4.9%) were retired. Currently 72 (50.3%) workers continue to perform physical work and 18 (12.6%) did not return to work. Conclusions: Labor reintegration occurred in less than half of the cases ruled. The main cause of the non-reintegration was the unjustified dismissal by the company where the accident occurred. Not reintegrating into the same workplace has: legal, economic, medical and social implications to the worker.

Introducción: las lesiones de mano derivadas de accidentes de trabajo constituyen una de las principales causas de discapacidad en los trabajadores. Todo trabajador dictaminado con Incapacidad Permanente Parcial (IPP), jurídicamente debe ser reinsertado a su mismo centro de trabajo. Objetivo: conocer la prevalencia de reinserción y causas de no reinserción laboral en trabajadores con IPP por lesiones de mano. Material y Métodos: estudio descriptivo, observacional y retrospectivo, que incluyó el 100% de los dictámenes de IPP por lesiones de mano, generados del 2012 al 2016 en la UMF 61 de Veracruz. Resultados: se analizaron 143 casos, 127 (88.8%) fueron hombres y 16 (11.2%) mujeres, con edad media 37.3 ± 11.6 años. La reinserción laboral en la misma empresa se presentó en 60 (42%) de los casos, 50 (35%) se reinsertaron en otra empresa y 33 (23.1%) no se reinsertaron al trabajo. Respecto de la terminación laboral: 51 (35.7%) trabajadores fueron despedidos posterior a su dictaminación, 13 (9.1%) renunciaron, 12 (8.4%) finalizaron su contrato, y 7 (4.9%) fueron jubilados. Actualmente 72 (50.3%) trabajadores continúa realizando un trabajo físico y 18 (12.6%) no volvió a trabajar. Conclusiones: la reinserción laboral se presentó en menos de la mitad de los casos. La principal causa de no reinserción fue el despido injustificado por la empresa donde ocurrió el accidente. No reintegrarse al mismo centro de trabajo conlleva implicaciones: legales, económicas, médicas y sociales al trabajador.

Prevalence and Distribution of Human Papillomavirus Genotypes (1997-2019) and Their Association With Cervical Cancer and Precursor Lesions in Women From Southern Mexico.

BACKGROUND: Cervical cancer (CC) is the fourth most common malignancy of the female genital tract. Human Papillomavirus (HPV) is the main cause of precancerous lesions and CC cases worldwide. OBJECTIVE: We assessed the prevalence and distribution of HPV types and their association with precancerous lesions and CC. METHODS: HPV genotypes were detected by 3 methods depending on the year of in which the sample was analyzed: MY09/11 RFLPs (1997 to 2010), GP5+/6+ primer systems (2005 to 2010) and INNO-LiPA HPV Genotyping Extra (2010 to 2019) in cervical samples (No-IL: 4445; LSIL: 2464; HSILs: 151 and CC: 253) from women from southern Mexico. RESULTS: The overall HPV prevalence was 54.17%, and hpv-16 was the most common genotype. In single infection, the high-risk HPV genotypes (group 1) were associated with squamous intraepitelial lesions (LSIL: HPV-39 (OR = 10.58, 95% CI 4.09-27.36, P < .001); HSIL: HPV-31 (OR = 14.76, 95% CI 6.56-33.20, P < .001); and CC: HPV-16 (OR = 25.01, 95% CI 18.83-33.21, P < .001). In multiple infections, the HPV genotypes (HPV-16 and HPV-18) were also associated with a high risk of lesions [LSIL: HPV-18 (OR = 3.45; 95% CI 1.36-8.91; P = .009); HSIL: HPV-18 (OR = 5.12; 95% CI 1.21-21.68; P = .026); and CC: HPV-16 (OR = 3.03; 95% CI 1.72-5.32; P < .001)] compared to single infection. In the analysis adjusted for age, giving birth, and cigarette smoking, a significant increase in the risk of LSIL, HSIL, and CC was maintained. CONCLUSIONS: This study provides current data on the prevalence and distribution of HPV genotypes in women from southern Mexico, which could serve as a valuable reference to guide nationwide CC screening programs and provide scientific evidence that could be useful for vaccine development efforts. Likewise, it was identified that infection with carcinogenic HPV genotypes is an independent risk factor for LSIL, HSIL, and CC.

GLUT1, LDHA, and MCT4 Expression Is Deregulated in Cervical Cancer and Precursor Lesions.

Metabolic reprogramming is typical in cancerous cells and is required for proliferation and cellular survival. In addition, oncoproteins of high-risk human papillomavirus (HR-HPV) are involved in this process. This study evaluated the relationship between glucose transporter I (GLUT1), lactate dehydrogenase A (LDHA), and monocarboxylate transporter type 4 (MCT4) expression and cervical intraepithelial neoplasia (CIN) and invasive cervical carcinoma (ICC) with HR-HPV infection. The protein expression was evaluated in women with CIN I (n=20), CIN II/III (n=16), or ICC (n=24) by immunohistochemistry. The protein expression was analyzed qualitatively by van Zummeren score and quantitatively by Image ProPlus 6 software. LDHA expression increases in HPV-16 infection. In the CIN I group, GLUT1 immunostaining has a 35% protein expression at the membrane level at more than two thirds of the epithelium, which increased by 21.25% more in CIN II/III in more than two thirds of the epithelium. While LDHA and MCT4 in CIN I mostly do not present immunostaining, or this was only limited to the basal stratum, this expression is increased in CIN II/III and ICC cases. The GLUT1, LDHA, and MCT4 expression increased in ICC. The overexpression in high-grade CIN with HR-HPV infection shows a higher risk for cervical carcinoma progression.

Transcription factors modulate RNA polymerase conformational equilibrium.

RNA polymerase (RNAP) frequently pauses during the transcription of DNA to RNA to regulate gene expression. Transcription factors NusA and NusG modulate pausing, have opposing roles, but can bind RNAP simultaneously. Here we report cryo-EM reconstructions of Escherichia coli RNAP bound to NusG, or NusA, or both. RNAP conformational changes, referred to as swivelling, correlate with transcriptional pausing. NusA facilitates RNAP swivelling to further increase pausing, while NusG counteracts this role. Their structural effects are consistent with biochemical results on two categories of transcriptional pauses. In addition, the structures suggest a cooperative mechanism of NusA and NusG during Rho-mediated transcription termination. Our results provide a structural rationale for the stochastic nature of pausing and termination and how NusA and NusG can modulate it.

The CpG island methylator phenotype increases the risk of high-grade squamous intraepithelial lesions and cervical cancer.

BACKGROUND: High-risk human papillomavirus (HR-HPV) infection is the main cause of cervical cancer, but additional alterations are necessary for its development. Abnormal DNA methylation has an important role in the origin and dissemination of cervical cancer and other human tumors. In this work, we analyzed the methylation of eight genes (AJAP1, CDH1, CDH13, MAGI2, MGMT, MYOD1, RASSF1A and SOX17) that participate in several biological processes for the maintenance of cell normality. We analyzed DNA methylation by methylation-specific PCR (MSP) and HPV infection using the INNO­LiPA genotyping kit in 59 samples diagnostic of normal cervical tissue (non-SIL), 107 low-grade squamous intraepithelial lesions (LSILs), 29 high-grade squamous intraepithelial lesions (HSILs) and 51 cervical cancers (CCs). RESULTS: We found that all samples of LSIL, HSIL, and CC were HPV-positive, and the genotypes with higher frequencies were 16, 18, 51 and 56. In general, the genes analyzed displayed a significant tendency toward an increase in methylation levels according to increasing cervical lesion severity, except for the CDH13 gene. High CpG island methylator phenotype (CIMP) was associated with a 50.6-fold (95% CI 4.72-2267.3)-increased risk of HSIL and a 122-fold risk of CC (95% CI 10.04-5349.7). CONCLUSIONS: We found that CIMP high was significantly associated with HSIL and CC risk. These results could indicate that CIMP together with HR-HPV infection and other factors participates in the development of HSIL and CC.

Structural basis for safe and efficient energy conversion in a respiratory supercomplex.

Proton-translocating respiratory complexes assemble into supercomplexes that are proposed to increase the efficiency of energy conversion and limit the production of harmful reactive oxygen species during aerobic cellular respiration. Cytochrome bc complexes and cytochrome aa3 oxidases are major drivers of the proton motive force that fuels ATP generation via respiration, but how wasteful electron- and proton transfer is controlled to enhance safety and efficiency in the context of supercomplexes is not known. Here, we address this question with the 2.8 Å resolution cryo-EM structure of the cytochrome bcc-aa3 (III2-IV2) supercomplex from the actinobacterium Corynebacterium glutamicum. Menaquinone, substrate mimics, lycopene, an unexpected Qc site, dioxygen, proton transfer routes, and conformational states of key protonable residues are resolved. Our results show how safe and efficient energy conversion is achieved in a respiratory supercomplex through controlled electron and proton transfer. The structure may guide the rational design of drugs against actinobacteria that cause diphtheria and tuberculosis.

Expression of HIF-1α and Genes Involved in Glucose Metabolism Is Increased in Cervical Cancer and HPV-16-Positive Cell Lines.

Cervical cancer (CC) is the most common cancer in women in the lower genital tract. The main risk factor for developing CC is persistent infection with HPV 16. The E6 and E7 oncoproteins of HPV 16 have been related to metabolic reprogramming in cancer through the regulation of the expression and stability of HIF-1α and consequently of the expression of its target genes, such as HIF1A (HIF-1α), SLC2A1 (GLUT1), LDHA, CA9 (CAIX), SLC16A3 (MCT4), and BSG (Basigin or CD147), which are involved in glucose metabolism. This work aimed to evaluate the expression of HIF-1α, GLUT1, LDHA, CAIX, MCT4, and Basigin in patient samples and CC cell lines. To evaluate the expression level of HIF1A, SLC2A1, LDHA, CA9, SLC16A3, and BSG genes in tissue from patients with CC and normal tissue, the TCGA dataset was used. To evaluate the expression level of these genes by RT-qPCR in CC cell lines, HPV-negative (C-33A) and HPV-16-positive (SiHa and Ca Ski) cell lines were used. Increased expression of HIF1A, SLC2A1, LDHA, SLC16A3, and BSG was found in Ca Ski and CA9 in SiHa compared to C-33A. Similar results were observed in CC tissues compared to normal tissue obtained by bioinformatics analysis. In conclusion, the expression of HIF-1α, GLUT1, LDHA, CAIX, MCT4, and BSG genes is increased in CC and HPV-16-positive cell lines.

Deep learning improves macromolecule identification in 3D cellular cryo-electron tomograms.

Cryogenic electron tomography (cryo-ET) visualizes the 3D spatial distribution of macromolecules at nanometer resolution inside native cells. However, automated identification of macromolecules inside cellular tomograms is challenged by noise and reconstruction artifacts, as well as the presence of many molecular species in the crowded volumes. Here, we present DeepFinder, a computational procedure that uses artificial neural networks to simultaneously localize multiple classes of macromolecules. Once trained, the inference stage of DeepFinder is faster than template matching and performs better than other competitive deep learning methods at identifying macromolecules of various sizes in both synthetic and experimental datasets. On cellular cryo-ET data, DeepFinder localized membrane-bound and cytosolic ribosomes (roughly 3.2 MDa), ribulose 1,5-bisphosphate carboxylase-oxygenase (roughly 560 kDa soluble complex) and photosystem II (roughly 550 kDa membrane complex) with an accuracy comparable to expert-supervised ground truth annotations. DeepFinder is therefore a promising algorithm for the semiautomated analysis of a wide range of molecular targets in cellular tomograms.