In silico analysis of genomic variables associated to HPV16 integration sites / Análisis in silico de variables genómicas asociadas a sitios de integración de HPV16

Background: Despite current prophylactic interventions, a significant proportion of patients suffers a cancer-specific mortality, leading to a global awareness of the importance of identifying factors associated to the etiology of HPV-associated cancer. According to this, HPV-DNA integration into human genome is an important event in the pathogenesis. Purpose: To identify in silico, molecular regions of the genome where the HPV integration events occur Methods: We performed a bioinformatic study based on a systematic search in Medline through PubMed, Embase and Lilacs from inception to April 2019. We used the UCSC Genome Browser Home (https://genome.ucsc.edu) to evaluate the genetic environment. Results: HPV integration sites by anatomical location related to cervical cancer were 374 (61%). In addition, 325 (87%) of these integration sites had HPV-16, 21 (5%) had HPV-18 and 28 (7%) had another type of genotype. Oro-pharyngeal cavity was the second anatomic site with 162 (26%) integration sites. It is noteworthy that the HPV-16 was found integrated into 160 (99%) analyzed sites. Conclusion: Our results suggest that many of the integration sites reported in the scientific literature are HPV 16 from squamous cell carcinomas and 50% of HPV16 were integrated into transcriptional units that might affect the expression of gene target.

Antecedentes: A pesar de las intervenciones profilácticas actuales, una proporción significativa de pacientes muere debido al cáncer, lo que aumenta la conciencia global de la importancia de identificar los factores asociados a la etiología del cáncer asociado al VPH. Según esto, la integración del ADN-VPH en el genoma humano es un evento importante en la patogénesis. Propósito: Identificar in silico, las regiones moleculares del genoma donde ocurren los eventos de integración del VPH Métodos: Realizamos un estudio bioinformático basado en una búsqueda sistemática en Medline a través de PubMed, Embase y Lilacs desde el inicio hasta abril de 2019. Utilizamos el UCSC Genome Browser Home (https://genome.ucsc.edu) para evaluar el entorno genético. Resultados: Los sitios de integración del VPH relacionados con el cáncer de cuello uterino fueron 374 (61%). Además, 325 (87%) de estos sitios de integración tenían VPH-16, 21 (5%) tenían VPH-18 y 28 (7%) tenían otro tipo de genotipo. La cavidad orofaríngea fue el segundo sitio anatómico con 162 (26%) sitios de integración. Es de destacar que el VPH-16 se encontró integrado en 160 (99%) sitios analizados. Conclusión: Nuestros resultados sugieren que muchos de los sitios de integración reportados en la literatura científica que presentan al VPH-16 son carcinomas de células escamosas y que el 50% de estos VPH-16 se integraron en unidades transcripcionales que podrían afectar la expresión de algún gen objetivo.

Comparative Assessment of DNA Targets and Amplification Methods for Leishmania (Viannia) Detection in Human Samples.

Multiple polymerase chain reaction (PCR)-based approaches have been developed for Leishmania detection in clinical and laboratory samples, and this diversity limits inter-study comparisons, meta-analyses, and generalization of findings. Towards harmonization of a molecular tool for detection of Leishmania (Viannia) for research purposes, we evaluated the concordance of 18SrDNA quantitative polymerase chain reaction (qPCR) and minicircle kinetoplastid DNA (mkDNA) PCR followed by Southern blot (PCR-SB) in in vitro infection systems and in lesion and mucosal swab samples from Colombian patients with cutaneous leishmaniasis caused by L. (Viannia). The lower limit of parasite detection of 18SrDNA qPCR and mkDNA PCR-SB was 10-1 promastigotes and one intracellular amastigote per reaction. From cutaneous lesions (n = 63), an almost perfect concordance was found between the methods (κ = 0.92, 95% CI: 0.82-1.00). Despite equal limits of detection, mkDNA PCR-SB was more efficient for parasite detection in mucosal samples than 18SrDNA qPCR or 18SrDNA digital droplet PCR. The high concordance, sensitivity, scaling potential, and feasibility of implementation of the 18SrDNA qPCR, support its selection as the L. (Viannia) in research laboratories, as a first step towards harmonization of research protocols in the region.