Browsing by Author "Corvalán Rodríguez, Alejandro"
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- ItemFactores de riesgo de alteraciones citológicas del cuello uterino en mujeres Chilenas: Un estudio de casos y controles(2010) Solís, M. T.; Aguayo González, Francisco Renan; Vargas, M.; Olcay, F.; Puschel Illanes, Klaus; Corvalán Rodríguez, Alejandro; Ferreccio Readi, Catterina
- ItemGenotipos de virus papiloma humano (VPH) en pacientes con cáncer cérvico-uterino en un hospital público y una clínica privada de Santiago, Chile(2010) Valdivia Leiva, Isabel Margarita; Aguayo González, Francisco Renan; Pruyas A., Martha; Snijders, Peter J. F.; Corvalán Rodríguez, Alejandro; Ferreccio Readi, Fresia CatterinaWe compared HPV genotypes among squamous cervical cancer samples from a public hospital (n = 55) and a private clinic (n = 35 cases) of Santiago. Paraffin-embedded specimens were analyzed by PCR followed by an immunoenzimatic assay. Reverse line blotting was used for the identification of 36 HPV genotypes. We found HPV DNA in 94.4% of all cancers. Single infections: HPV16: 40.0%, (clinic 37.1%, hospital 41.8%) VPH18:7.8% (clinic 2.9%, hospital 10.9%); single+multiple infections: VPH16: 61.1% (clinic 53.1%, hospital 71.7%), VPH18: 34.4% (clinic 21.9%, hospital 45.2%). HPV16 or HPV18 occurred in 75.6% of cases, higher in the hospital than the clinic (87.3%-95% CI: 84.9-96.3 - and 57.1%-95% CI: 46.6-66 - respectively, p = 0.002). Other genotypes in single infections: HPV 26, 31, 33, 45, 58, 67; in co-infections: HPV 35,52,56,59 and 66. HPV16 but specially HPV18 were significantly more frequent in the public hospital; 75.6% of squamous cervical cancer were associated to the vaccine preventable HPV16/18.
- ItemHelicobacter pylori-induced inflammation and epigenetic changes during gastric carcinogenesis(Baishideng Publishing Group Inc., 2015) Valenzuela, Manuel A.; Canales, Jimena; Corvalán Rodríguez, Alejandro; Quest, Andrew F. G.The sequence of events associated with the development of gastric cancer has been described as "the gastric precancerous cascade". This cascade is a dynamic process that includes lesions, such as atrophic gastritis, intestinal metaplasia and dysplasia. According to this model, Helicobacter pylori (H. pylori) infection targets the normal gastric mucosa causing non-atrophic gastritis, an initiating lesion that can be cured by clearing H. pylori with antibiotics or that may then linger in the case of chronic infection and progress to atrophic gastritis. The presence of virulence factors in the infecting H. pylori drives the carcinogenesis process. Independent epidemiological and animal studies have confirmed the sequential progression of these precancerous lesions. Particularly long-term follow-up studies estimated a risk of 0.1% for atrophic gastritis/intestinal metaplasia and 6% in case of dysplasia for the long-term development of gastric cancer. With this in mind, a better understanding of the genetic and epigenetic changes associated with progression of the cascade is critical in determining the risk of gastric cancer associated with H. pylori infection. In this review, we will summarize some of the most relevant mechanisms and focus predominantly but not exclusively on the discussion of gene promoter methylation and miRNAs in this context.
- ItemMétodo no invasivo de diagnóstico temprano de cáncer gástrico, usando como biomarcador los niveles de metilación de la secuencia de ADN del promotor del microRNA -335-5p (Chile, concesión n° 64616)Corvalán Rodríguez, Alejandro; Sandoval Bórquez, Alejandra
- ItemTeneurin protein family: an emerging role in human tumorigenesis and drug resistance(2012) Brañes Yunusic, Jorge Antonio; Corvalán Rodríguez, Alejandro; Roa, Iván; Wollscheid, Bernd; Ziegler, AnnemarieUsing a chemoproteomic strategy, we recently demonstrated the expression of teneurin-2, a transmembrane glycoprotein, in the majority of malignant mesothelioma cell lines. This finding was unexpected since no formally organized evidence existed to implicate teneurins in human malignancy. For this reason, here we provide a comprehensive review on the expression of teneurins in human tumors and cell lines. Current evidence supports the aberrant expression of teneurins in various tumor types, their involvement in cancer-related regulatory networks, and their potential participation in drug resistance. Structural attributes of teneurins could enable the detection of shedded forms in body fluids for clinical applications. (C) 2012 Elsevier Ireland Ltd. All rights reserved.
- ItemThe Phylogeographic Diversity of EBV and Admixed Ancestry in the Americas-Another Model of Disrupted Human-Pathogen Co-Evolution(2019) Corvalán Rodríguez, Alejandro; Ruedlinger, Jenny; Mayo, Tomás de; Polakovicova, Iva; González-Hormázabal, Patricio; Aguayo, FranciscoEpstein-Barr virus (EBV) is an etiological agent for gastric cancer with significant worldwide variations. Molecular characterizations of EBV have shown phylogeographical variations among healthy populations and in EBV-associated diseases, articularly the cosegregated BamHI-I fragment and XhoI restriction site of exon 1 of the LMP-1 gene. In the Americas, both cosegregated variants are present in EBV carriers, which aligns with the history of Asian and European human migration to this continent. Furthermore, novel recombinant variants have been found, reflecting the genetic makeup of this continent. However, in the case of EBV-associated gastric cancer (EBV-associated GC), the cosegregated European BamHI-“i” fragment and XhoI restriction site strain prevails. Thus, we propose that a disrupted coevolution between viral phylogeographical strains and mixed human ancestry in the Americas might explain the high prevalence of this particular gastric cancer subtype. This cosegregated region contains two relevant transcripts for EBV-associated GC, the BARF-1 and miR-BARTs. Thus, genome-wide association studies (GWAS) or targeted sequencing of both transcripts may be required to clarify their role as a potential source of this disrupted coevolution.