RESUMO
Epstein-Barr virus (EBV) is linked to lymphoma and epithelioma but lacks drugs specifically targeting EBV-positive tumors. BamHI A Rightward Transcript (BART) miRNAs are expressed in all EBV-positive tumors, suppressing both lytic infection and host cell apoptosis. We identified suberoylanilide hydroxamic acid (SAHA), an inhibitor of histone deacetylase enzymes, as an agent that suppresses BART promoter activity and transcription of BART miRNAs. SAHA treatment demonstrated a more pronounced inhibition of cell proliferation in EBV-positive cells compared to EBV-negative cells, affecting both p53 wild-type and mutant gastric epithelial cells. SAHA treatment enhanced lytic infection in wild-type EBV-infected cells, while also enhancing cell death in BZLF1-deficient EBV-infected cells. It reduced BART gene expression by 85% and increased the expression of proapoptotic factors targeted by BART miRNAs. These findings suggest that SAHA not only induces lytic infection but also leads to cell death by suppressing BART miRNA transcription and promoting the apoptotic program.
Assuntos
Apoptose , Herpesvirus Humano 4 , Ácidos Hidroxâmicos , MicroRNAs , Vorinostat , Vorinostat/farmacologia , Apoptose/efeitos dos fármacos , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/fisiologia , Herpesvirus Humano 4/efeitos dos fármacos , Ácidos Hidroxâmicos/farmacologia , Regulação Viral da Expressão Gênica/efeitos dos fármacos , Linhagem Celular , Inibidores de Histona Desacetilases/farmacologia , Regiões Promotoras Genéticas , Proliferação de Células/efeitos dos fármacosRESUMO
DNA methylation of both viral and host DNA is one of the major mechanisms involved in the development of Epstein-Barr virus-associated gastric carcinoma (EBVaGC); thus, epigenetic treatment using demethylating agents would seem to be promising. We have verified the effect of MC180295, which was discovered by screening for demethylating agents. MC180295 inhibited cell growth of the EBVaGC cell lines YCCEL1 and SNU719 in a dose-dependent manner. In a cell cycle analysis, growth arrest and apoptosis were observed in both YCCEL1 and SNU719 cells treated with MC180295. MKN28 cells infected with EBV were sensitive to MC180295 and showed more significant inhibition of cell growth compared to controls without EBV infection. Serial analysis of gene expression analysis showed the expression of genes belonging to the role of BRCA1 in DNA damage response and cell cycle control chromosomal replication to be significantly reduced after MC180295 treatment. We confirmed with quantitative PCR that the expression levels of BRCA2, FANCM, RAD51, TOP2A, and CDC45 were significantly decreased by MC180295. LMP1 and BZLF1 are EBV genes with expression that is epigenetically regulated, and MC180295 could up-regulate their expression. In conclusion, MC180295 inhibited the growth of EBVaGC cells by suppressing DNA repair and the cell cycle.
Assuntos
Carcinoma , Infecções por Vírus Epstein-Barr , Neoplasias Gástricas , Carcinoma/patologia , Ciclo Celular/genética , DNA Helicases/metabolismo , Reparo do DNA , Infecções por Vírus Epstein-Barr/complicações , Infecções por Vírus Epstein-Barr/genética , Infecções por Vírus Epstein-Barr/patologia , Herpesvirus Humano 4/genética , Humanos , Neoplasias Gástricas/patologiaRESUMO
Myiasis is an infestation of maggot, which is frequently associated with poor personal hygiene and environmental sanitation. A 78-year-old female breast cancer patient visited clinic complaining of irritation, itching, and pain within the ulcerous cancer lesion for 3 weeks. Many maggots were found in the lesion. A total of 30 maggots were removed and identified to be 3rd stage of larvae of metallic fly. This is the first case of wound myiasis in advanced breast carcinoma as a complication of untreated or drug-induced ulcer.