RESUMEN
BACKGROUND/AIM: Oxazolinodoxorubicin (O-DOX) and oxazolinodaunorubicin (O-DAU) are derivatives of anthracyclines (DOX and DAU) with a modified daunosamine moiety. We aimed to clarify their mechanisms of action by investigating intracellular accumulation and effects on the cell cycle, phosphatidylserine externalization, and proteasome 20S activity. MATERIALS AND METHODS: Experimental model consisted of SKOV-3, A549 and HepG2 cells. Compounds were used at the concentration of 80nM. Intracellular accumulation, drug uptake, and proteasome 20S activity were evaluated by fluorimetric methods. The effects on the cell cycle and phosphatidylserine externalization were measured by flow cytometry. RESULTS: O-DOX was equivalent to DOX in terms of inducing G2/M arrest, but O-DAU was less potent in SKOV-3, HepG2, and A549 cells. O-DOX had the greatest effect on initiating apoptosis in all tested cells. Externalization of phosphatidylserine was significantly higher following O-DOX treatment compared with control cells and cells incubated with DOX. The intracellular accumulation and uptake of the derivatives were similar to those of the reference drugs. Tested compounds are able to activate proteasome 20S activity. CONCLUSION: Our results extended the understanding of the toxicity, mechanism of action, and biochemical properties of oxazoline derivatives of doxorubicin and daunorubicin, including their effects on cell cycle, apoptosis and DNA degradation.
Asunto(s)
Antibióticos Antineoplásicos/farmacología , Daunorrubicina/análogos & derivados , Antibióticos Antineoplásicos/química , Apoptosis/efectos de los fármacos , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Daunorrubicina/química , Daunorrubicina/farmacología , Regulación Neoplásica de la Expresión Génica , Humanos , Estructura Molecular , Fosfatidilserinas/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismoRESUMEN
Oxazolinodoxorubicin (O-DOX) and oxazolinodaunorubicin (O-DAU) are novel anthracycline derivatives with a modified daunosamine moiety. In the present study, we evaluated the cytotoxicities, genotoxicities and abilities of O-DOX and O-DAU to induce apoptosis in cancer cell lines (SKOV-3; A549; HepG2), and compared the results with their parent drugs. We assessed antiproliferative activity by MTT assay. We evaluated apoptosis-inducing ability by double-staining with fluorescent probes (Hoechst 33258/propidium iodide), and by determining expression levels of genes involved in programmed cell death by reverse transcription-polymerase chain reaction. Genotoxicities of the compounds were tested by comet assays. Oxazolinoanthracyclines demonstrated high anti-tumor activity. O-DOX had significantly higher cytotoxicity, apoptosis-inducing ability, and genotoxicity compared with parental doxorubicin (DOX) in all tested conditions, while O-DAU activity differed among cell lines. The mechanism of oxazoline analog action appeared to involve the mitochondrial pathway of programmed cell death. These results provide further information about oxazoline derivatives of commonly used anthracycline chemotherapy agents. O-DOX and O-DAU have the ability to induce apoptosis in tumor cells.