Detección de virus papiloma humano (mucoso y asociado a epidermodisplasia verruciforme) en carcinomas basocelulares y espinocelulares cutáneos de pacientes inmunocompetentes / Detection of human papillomavirus in basal and squamous cell carcinoma of immunocompetent patients

Estudios epidemiológicos y experimentales han confirmado el rol del Virus Papiloma Humano (VPH) en la patogénesis del cáncer de piel no melanoma (CCNM) en pacientes inmunosuprimidos, con epidermodisplasia verruciforme (EV) y en pacientes trasplantados. El rol que juega este virus en pacientes inmunocompetentes está aún por ser demostrado. Objetivos: Determinar la presencia de VPH mucosos y EV relacionados en tumores cutáneos no melanoma, queratosis actínicas y en piel sana de pacientes inmunocompetentes.Material y Métodos: Se analizaron 19 biopsias de tumores de 18 pacientes con carcinomas basocelulares, 10 biopsias de 4 pacientes con carcinomas espinocelulares, 4 biopsias de 3 pacientes con queratosis actínicas; y 33 biopsias de piel perilesional de nevos extirpados de 33 sujetos control. Todas estas muestras fueron analizadas mediante PCR usando primers estandarizados para la búsqueda de VPH mucosos (partidores GP5+/GP6+) y EV-VPH (partidores CP65-CP70 y CP66-CP69). Resultados: No se detectaron VPH mucosos ni EV relacionados en ninguna de las muestras analizadas.Discusión: Las biopsias de los pacientes inmunocompetentes no se asociaron a una infección detectable por VPH. Este estudio no apoya la asociación en nuestra población entre la infección por VPH y el desarrollo de cáncer de piel no melanoma en sujetos inmunocompetentes.

Epidemiological and experimental studies have confirmed the role of human papillomavirus (HPV) in the pathogenesis of non-melanoma skin cancer (NMSC) in immunosuppressed patients, in patients with epidermodysplasia verruciformis (EV), and in recipients of organ transplant. The role of this virus has not yet been demonstrated in immunocompetent patients. Objectives: To determine the presence of mucosal HPV and EV-HPV in non-melanoma cutaneous tumors, actinic keratosis and healthy skin in immunocompetent patients.Methods: 19 tumor biopsies (fresh frozen tissue) from 18 patients with basal cell carcinoma, 10 biopsies from 4 patients with squamous cell carcinoma, and 4 biopsies from 3 patients with actinic keratosis, as well as 33 biopsies of perilesional skin from nevi from 33 control subjects. All samples were analyzed via polymerase chain reaction (PCR) using standardized consensus primers for the detection of mucosal HPV (GP5+/GP6+) and EV-HPV (CP65-CP70 and CP66-CP69). Results: Mucosal HPV and EV- HPV were not detected in any of the biopsies of the study patients, despite external positive controls and excellent DNA quality.Conclusions: The biopsies of the immunocompetent patients were not associated with a detectable HPV infection. Our data do not support the role of HPV as an etiologic factor in NMSC in immunocompetent patients.

Identificación de asociaciones clínico-patológicas e hipermetilación de genes supresores de tumores en cáncer gástrico difuso a través de análisis de Hierarchical clustering / Hierarchical clustering analysis to detect associations between clinical and pathological features of gastric tumors and hypermethylation of suppressor genes

Background:Methylation is an inactivation mechanism for tumor suppressor genes, that can have important clinical implications. Aim: To analyze the methylation status of 11 tumor suppressor genes in pathological samples of diffuse gastric cancer. Material and methods: Eighty three patients with diffuse gastric cancer with information about survival and infection with Epstein Barr virus, were studied. DNA was extracted from pathological slides and the methylation status of genes p14, p15, p16, APC, p73, FHIT, E-caderin, SEMA3B, BRCA-1, MINT-2 y MGMT, was studied using sodium bisulphite modification and polymerase chain reaction. Results were grouped according to the methylation index or Hierarchical clustering (TIGR MultiExperiment Viewer). Results: Three genes had a high frequency of methylation (FHIT, BRCA1, APC), four had an intermediate frequency (p15, MGMT, p14, MINT2) and four had a low frequency (p16, p73, E-cadherin, SEMA3B). The methylation index had no association with clinical or pathological features of tumors or patients survival. Hierarchical clustering generated two clusters. One grouped clinical and pathological features with FHIT, BRCA1, and APC and the other grouped the other eight genes and Epstein Barr virus infection. Two significant associations were found, between APC and survival and p16/p14 and Epstein Barr virus infection. Conclusions: Hierarchical clustering is a tool that identifies associations between clinical and pathological features of tumors and methylation of tumor suppressor genes.

Rol patogénico del gen supresor de tumores PTEN en cáncer ovárico asociado a endometriosis / Pathogenic role of PTEN tumor suppressor gene in ovarian cancer associated to endometriosis

Background: Endometrioid carcinoma and clear cell carcinoma of the ovary are associated to endometriosis. Somatic mutations of PTEN (10q23.3) are present in endometrial endometrioid carcinoma. Therefore, these mutations could be also present in ovarian tumors. Molecular studies show that solitary endometriotic cysts are monoclonal, have aneuploid DNA, have a loss of 9p,11q and 22q heterozygosity (LOH) and a higher cellular proliferation index of the epithelial component. Aim: To determine the cellular proliferation index using Ki 67, the immunohistochemical expression of PTEN and LOH in patients with ovarian endometriosis without atypia (EN), ovarian endometriosis with atypia (EA) and endometriosis with adjacent ovarian carcinoma (ET). Material and methods: Paraffin embedded samples of 37 endometrioid and clear cell carcinomas of the ovary (CC/CE), 15 solitary ovarian EN and 15 ovarian EA, were studied. Expression of Ki 67 and PTEN was measured by immunohistochemistry. LOH of 10q23.3 locus was measured by polymerase chain reaction. Results: Ki 67 was 5.5 and 2.3% in EA and EN, respectively (p <0.005). There was a histological correlation between EA and a higher cellular proliferation index. PTEN was negative in 5 of 15 EN, 9 of 15 EA and 30 of 37 CE/CC. There was a correlation between LOH and loss of PTEN protein in EN, EA and ET (60%). Conclusions: Negative expression on PTEN in EN; EA; ET and CE/CC is a manifestation of the inactivation of this gene. The mechanisms that cause this inactivation, must be elucidated.