ABSTRACT
BACKGROUND Epigenetic modifications in host cells, like p16 ink4a methylation, have been considered as putative complementary mechanisms for cancer development. Because only a small proportion of infected women develop cervical cancer, other factors might be involved in carcinogenesis, either independently or in association with high-risk human papillomavirus (HR-HPV) infections, including epigenetic factors. OBJECTIVES We hypothesised that p16 ink4a methylation might have a role in cancer development driven by HPV16, mainly in the presence of intact E1/E2 genes. Thus, our objectives were to assess the status of p16 ink4a methylation and the HPV16 E1/E2 integrity in samples in different stages of cervical diseases. METHODS Presence of HPV16 was determined by E6 type-specific polymerase chain reaction (PCR). Methylation status of the p16 ink4a promoter was assessed by methylation-specific PCR in 87 cervical specimens comprising 29 low-grade (LSIL), 41 high-grade (HSIL) lesions, and 17 cervical cancers (CC). Characterisation of E1 and E2 disruption (as an indirect indicator of the presence of episomal viral DNA) was performed by PCR amplifications. FINDINGS We observed a significantly increased trend (nptrend = 0.0320) in the proportion of methylated p16 ink4a in cervical samples during cancer development. Concomitant E1 and E2 disruptions were the most frequent pattern found in all groups: CC (76%), HSIL (54%), and LSIL (73%). No statistically significant differences between p16 ink4a methylation and E1/E2 integrity, in histological groups, was observed. MAIN CONCLUSIONS There was an increase in methylation of the p16 ink4a promoter from pre-neoplastic lesions to cancer. Additionally, a high frequency of E1/E2 disruptions in LSIL/HSIL suggested that viral DNA integration was an early event in cervical disease. Moreover, the methylation status was apparently independent of HPV16 integrity.
Subject(s)
Humans , Papillomaviridae/physiology , Uterine Cervical Neoplasms/prevention & control , Methylation/drug effects , Cyclin-Dependent Kinase Inhibitor p16 , Integration Host Factors/therapeutic useABSTRACT
Antecedentes: menos de la mitad de los pacientes con hepatitis C logra eliminar el virus de manera sostenida después de la terapia con peginterferón alfa y ribavirina (Peg-IFN/RBV). Objetivos: la talidomida posee propiedades antiinflamatorias e inmunomoduladoras a través de la inhibición del TNF-α y al efecto estimulador sobre las células T CD8+. Métodos: se inició un estudio prospectivo y abierto de re-tratamiento de pacientes con hepatitis crónica C genotipo 1, no respondedores al tratamiento con Peg-IFN/RBV, mediante triple terapia añadiendo a los mismos antivirales 200 mg/día de talidomida. Resultados: ninguno de los once pacientes que fueron incluidos en el ensayo consiguió respuesta viral completa en la semana 12 ni respuesta viral sostenida. La dinámica viral en las 12 primeras semanas de tratamiento no difirió de la dinámica viral durante el primer curso de tratamiento. La triple terapia fue bien tolerada y solo un paciente desarrolló neuropatía bilateral autolimitada. Conclusiones: añadir talidomida al tratamiento estándar fue bien tolerado pero no incrementó la tasa de respuesta viral sostenida en pacientes con hepatitis C genotipo 1 no respondedores previos(AU)
Background: fewer than half of patients infected with hepatitis C virus (HCV) achieve sustained viral clearance after peginterferon alfa/ribavirin (Peg-IFN/RBV) therapy. Aims: thalidomide posses anti-inflammatory and immunomodulatory properties through inhibition of tumor necrosis factor and costimulatory effect on human CD8+ T cells. Methods: we started a prospective, open label trial of retreatment of very-difficult-to-treat genotype 1 chronic hepatitis C patients (CHC) patients, who had failed to respond to the (Peg-IFN/RBV), with a triple therapy consisting in these same antivirals plus thalidomide 200 mg/day (the TRITAL study). Results: none of the eleven patients fulfilling the inclusion criteria and included in the trial reached complete early virological response or sustained virological response. Viral load decline after 12 weeks of triple therapy thalidomide-based retreatment did not differ from viral dynamics during the first course. The triple therapy was well tolerated and only one patient developed mild bilateral neuropathy. Conclusions: thalidomide addition to standard therapy is tolerated and did not increase the SVR rate in very-difficult-to-treat genotype 1 CHC patients. Different schedules are warranted to improve attempting retreatment of non responder CHC patients(AU)
