[Promoter hypermethylation gene patterns in gynecological tumors]. / Patrones de hipermetilación génica en tumores ginecológicos.

BACKGROUND AND OBJECTIVE: Gene silencing mediated by the aberrant methylation of the promoter region of DNA is involved in the inactivation of genes implicated in various metabolic pathways. Such a gene hypermethylation has become a useful molecular marker for the diagnosis, treatment and follow-up of cancer patients. Our objective is to analyze the patterns of gene hypermethylation in patients with gynecological tumors. PATIENTS AND METHODS: We selected 115 patients with gynecological cancers: 22 ovarian; 13 endometrial, 11 cervical-uterine and 69 breast cancers. By testing methylation-specific PCR, we studied the methylation status of genes CDNK2A (p16), APC1A, FHIT, CDH1 and hMLH1. RESULTS: The frequencies of gene methylation in genes p16, APC1A, FHIT, hMLH1 and CDH1 were 29.2%, 34%, 60.4%, 10.9% and 79.8%, respectively. 70% of cases showed at least two methylated genes, which means a rate of methylation >0.4. The lowest frequency of methylation was seen in ovarian cancer, while the highest one was observed in endometrial cancer. CONCLUSIONS: The results indicate that the aberrant methylation of the promoter region is an important event in carcinogenesis of gynecological tumors and that the pattern of gene methylation is associated with the nature of the tumor. These particular characteristics can deliver relevant information on the major metabolic pathways altered in each tumor type. In addition to complementary studies (ie, loss of expression and/or function), this represents a clinical tool for the proper management of the disease.

Patrones de hipermetilación génica en tumores ginecológicos / Promoter Hypermethylation gene patterns in gynecological tumors

Fundamento y objetivo: El silenciamiento génico mediado por la metilación aberrante de la región promotora del ácido desoxirribonucleico está implicado en la inactivación de genes involucrados en diversas vías metabólicas y se ha constituido en un marcador molecular útil en el diagnóstico, tratamiento y seguimiento de sujetos oncológicos. El objetivo de este trabajo es analizar los patrones de hipermetilación génica en mujeres con tumores ginecológicos. Sujetos y método: Se seleccionaron 115 mujeres con cánceres ginecológicos: 22 mujeres con cáncer de ovario (CO), 13 mujeres con cáncer de endometrio (CE), 11 mujeres con cáncer de cuello uterino y 69 mujeres con cáncer de mama. Mediante prueba de metilación específica por reacción en cadena de la polimerasa, se estudió el estado de metilación de los genes CDNK2A (p16), APC1A, FHIT, CDH1 y hMLH1.ResultadosLas frecuencias de metilación génica para los genes CDNK2A (p16), APC1A, FHIT, CDH1 y hMLH1 fueron del 29,2; 34; 60,4; 10,9, y 79,8%, respectivamente. El 70% de los casos presentó al menos 2 genes metilados, es decir, un índice de metilación superior a 0,4. La frecuencia de metilación más baja se observó en el CO, mientras que la frecuencia de metilación más alta se presentó en el CE. Conclusiones: Los resultados indican que la metilación aberrante de la región promotora es un acontecimiento importante en la carcinogénesis de los tumores ginecológicos y que el patrón de metilación génica se asocia a la naturaleza tumoral. Estas características particulares pueden entregar información relevante acerca de las principales vías metabólicas alteradas en cada tipo tumoral, información que sumada a estudios complementarios de pérdida de expresión o de función representa una herramienta clínica para el tratamiento adecuado de la enfermedad (AU)

Background and objective: Gene silencing mediated by the aberrant methylation of the promoter region of DNA is involved in the inactivation of genes implicated in various metabolic pathways. Such a gene hypermethylation has become a useful molecular marker for the diagnosis, treatment and follow-up of cancer patients. Our objective is to analyze the patterns of gene hypermethylation in patients with gynecological tumors. Patients and methods: We selected 115 patients with gynecological cancers: 22 ovarian; 13 endometrial, 11 cervical-uterine and 69 breast cancers. By testing methylation-specific PCR, we studied the methylation status of genes CDNK2A (p16), APC1A, FHIT, CDH1 and hMLH1.ResultsThe frequencies of gene methylation in genes p16, APC1A, FHIT, hMLH1 and CDH1 were 29.2%, 34%, 60.4%, 10.9% and 79.8%, respectively. 70% of cases showed at least two methylated genes, which means a rate of methylation >0.4. The lowest frequency of methylation was seen in ovarian cancer, while the highest one was observed in endometrial cancer. Conclusions: The results indicate that the aberrant methylation of the promoter region is an important event in carcinogenesis of gynecological tumors and that the pattern of gene methylation is associated with the nature of the tumor. These particular characteristics can deliver relevant information on the major metabolic pathways altered in each tumor type. In addition to complementary studies (ie, loss of expression and/or function), this represents a clinical tool for the proper management of the disease (AU)

Molecular description and similarity relationships among native germplasm potatoes (Solanum tuberosum ssp. tuberosum L.) using morphological data and AFLP markers

Chile is considered to be a sub-center of origin for the cultivated potato, with native and introduced genetic material coexisting in the country. Thus, the different varieties present in Chiloe Island are characterized by a rich diversity of forms, sizes, colours and phenological characteristics. In the present work, the level of polymorphism and the genetic relationship were studied by means of molecular markers using the amplified fragment length polymorphism (AFLP) technique and twenty-seven morphological characters. Twenty varieties of potatoes from the Chiloe Island were analyzed. The commercial variety Desirée and one specie from the Etuberosa series, Solanum fernandezianum, collected in the Juan Fernandez Island were included as controls. A similarity tree-diagram was made, based on all the AFLP bands generated in the range between 65 and 290 base pairs. With these tools, it was possible to identify molecular differences and similarities that might be associated with important morphological traits such as the predominant forms of the tuber, flower colour and resistance to disease.