RESUMEN
The anticancer antibiotic doxorubicine (DOX) is highly toxic and induces functional complications in vital organs. The effect of DOX on normal cells has not been examined in sufficient detail, and the search for compounds reducing DOX toxicity did not lead to success so far. It has been suggested that DOX induces death of cancer cells via p53-dependent apoptosis, however, the information regarding the role of p73 protein, a member of p53 tumor suppressor family, is scanty. Cytomegalovirus (CMV) induces an antiapoptosis program that allows its replication until death of the target cell. Our objectives were to examine the effect of DOX on normal cells (human fibroblasts), analyze the ability of CMV-induced antiapoptosis program to reduce DOX toxicity, and to evaluate the involvement of p73 protein and its isoforms in the regulation of death of CMV-infected and DOX-treated cells. Within a 24-h time period DOX caused death of about 70% human embryonic lung fibroblasts (HELF) in cell culture, this parameter decreased significantly in CMV-infected DOX-treated HELF cells. TUNEL has shown that the number of cells with DNA fragmentation decreases from 5.2% under the effect of DOX to 3.2% (P < 0.05) after combined CMV-DOX treatment. Analysis of mitotic figures revealed that DOX causes accumulation of mitotic cells, which was not observed in CMV-infected DOX-treated cells. PCR analysis of mRNA of two p73 protein isoforms (TAp73 and dNp73) has shown that in uninfected cells the expression of TAp73 isoform was low, while in CMV-infected cells level of TAp73 was significant and expression of dNp73 was demonstrated for the first time. Expression of TAp73 associated with lack of mitosis block. The activation of caspases 8, 9 and 3 in CMV-infected cells was registered but cell death was not, however, as massive as that caused by DOX. From these findings it can be concluded that CMV attenuates DOX-related damage to normal cells. It can be suggested that induction of TAp73 and dNp73 isoforms provides conditions for reduction of DOX effect which leads to DNA damage and death of normal cells.
Asunto(s)
Antibióticos Antineoplásicos/toxicidad , Apoptosis/efectos de los fármacos , Citomegalovirus/fisiología , Proteínas de Unión al ADN/metabolismo , Doxorrubicina/toxicidad , Fibroblastos/efectos de los fármacos , Proteínas Nucleares/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Autofagia/efectos de los fármacos , Biomarcadores/análisis , Línea Celular , Fragmentación del ADN/efectos de los fármacos , Proteínas de Unión al ADN/genética , Fibroblastos/metabolismo , Fibroblastos/virología , Humanos , Etiquetado Corte-Fin in Situ , Proteínas Nucleares/genética , Isoformas de Proteínas , ARN Mensajero/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Proteína Tumoral p73 , Proteínas Supresoras de Tumor/genéticaRESUMEN
The authors have obtained a panel of 7 monoclonal antibodies (MAbs) against pandemic influenza virus A/IIV-Moscow/01/2009 (HIN1)swl isolated in Russia. One MAb is directed to a NP protein linear epitope and interacts with all the influenza A viruses under study. Six other MAbs are directed to H1 hemagglutinin conformation-dependent determinants and detect homologous virus in the hemagglutination-inhibition test, enzyme immunoassay, immunofluorescence and virus neutralization tests. MAbs differentiate pandemic influenza viruses A(H1N1)swl from seasonal influenza A(H1N1), A(H3N2), and B viruses. The high neutralizing activity of MAbs permits their use to study the fine antigen structure of influenza virus hemagglutinin and to differentiate the A(H1N1) pandemic influenza viruses and offers promise for obtaining humanized antibodies in order to make specific prevention and treatment of influenza.