While p53-dependent apoptosis is triggered by combination of methyltransferase inhibitor decitabine (DAC) and histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA) in leukemic cell line CML-T1, reactive oxygen species (ROS) generation as well as survivin and Bcl-2 deregulation participated in DAC + SAHA-induced apoptosis in p53-deficient HL-60 cell line. Moreover, decrease of survivin expression level is accompanied by its delocalization from centromere-related position in mitotic cells suggesting that both antiapoptotic and cell cycle regulation roles of survivin are affected by DAC + SAHA action. Addition of subtoxic concentration of all-trans-retinoic acid (ATRA) increases the efficiency of DAC + SAHA combination on viability, apoptosis induction, and ROS generation in HL-60 cells but has no effect in CML-T1 cell line. Peripheral blood lymphocytes from healthy donors showed no damage induced by DAC + SAHA + ATRA combination. Therefore, combination of ATRA with DAC and SAHA represents promising tool for therapy of leukemic disease with nonfunctional p53 signalization.

• MeSH
• Apoptosis drug effects   MeSH
• Azacitidine analogs & derivatives   toxicity   MeSH
• Decitabine MeSH
• Down-Regulation drug effects   MeSH
• HL-60 Cells MeSH
• Inhibitor of Apoptosis Proteins metabolism   MeSH
• G2 Phase Cell Cycle Checkpoints drug effects   MeSH
• M Phase Cell Cycle Checkpoints drug effects   MeSH
• Hydroxamic Acids toxicity   MeSH
• Humans MeSH
• Lymphocytes cytology   drug effects   immunology   MeSH
• Cell Line, Tumor MeSH
• Tumor Suppressor Protein p53 deficiency   genetics   MeSH
• Antimetabolites, Antineoplastic pharmacology   MeSH
• Reactive Oxygen Species metabolism   MeSH
• Survivin MeSH
• Drug Synergism MeSH
• Tretinoin pharmacology   MeSH
• Vorinostat MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Azacitidine MeSH
• BIRC5 protein, human MeSH Browser
• Decitabine MeSH
• Inhibitor of Apoptosis Proteins MeSH
• Hydroxamic Acids MeSH
• Tumor Suppressor Protein p53 MeSH
• Antimetabolites, Antineoplastic MeSH
• Reactive Oxygen Species MeSH
• Survivin MeSH
• Tretinoin MeSH
• Vorinostat MeSH

Epigenetic therapy reverting aberrant acetylation or methylation offers the possibility to target preferentially tumor cells and to preserve normal cells. Combination epigenetic therapy may further improve the effect of individual drugs. We investigated combined action of demethylating agent decitabine and histone deacetylase inhibitor SAHA (Vorinostat) on different leukemic cell lines in comparison with peripheral blood lymphocytes. Large decrease of viability, as well as huge p21WAF1 induction, reactive oxygen species formation, and apoptotic features due to combined decitabine and SAHA action were detected in leukemic cell lines irrespective of their p53 status, while essentially no effect was observed in response to the combined drug action in normal peripheral blood lymphocytes of healthy donors. p53-dependent apoptotic pathway was demonstrated to participate in the wtp53 CML-T1 leukemic cell line response, while significant influence of reactive oxygen species on viability decrease has been detected in p53-null HL-60 cell line.

• MeSH
• Apoptosis drug effects   MeSH
• Azacitidine administration & dosage   analogs & derivatives   MeSH
• Decitabine MeSH
• Cells, Cultured MeSH
• Hydroxamic Acids administration & dosage   MeSH
• Leukemia drug therapy   pathology   physiopathology   MeSH
• Humans MeSH
• Lymphocytes cytology   drug effects   physiology   MeSH
• Antimetabolites, Antineoplastic administration & dosage   MeSH
• Antineoplastic Combined Chemotherapy Protocols administration & dosage   MeSH
• Vorinostat MeSH
• Dose-Response Relationship, Drug MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Azacitidine MeSH
• Decitabine MeSH
• Hydroxamic Acids MeSH
• Antimetabolites, Antineoplastic MeSH
• Vorinostat MeSH

Reactive oxygen species play an important role in the process of apoptosis in many cell types. In this paper, we analyzed the role of ROS in DNA-damaging agents (actinomycin D or decitabine), which induced apoptosis of leukemia cell line CML-T1 and normal peripheral blood lymphocytes (PBL). The possibility of synergism with histone deacetylase inhibitors butyrate or SAHA is also reported. We found that in cancer cell line, ROS production significantly contributed to apoptosis triggering, while in normal lymphocytes treated by cytostatic or cytotoxic drugs, necrosis as well as apoptosis occurred and large heterogeneity of ROS production was measured. Combined treatment with histone deacetylase inhibitor did not potentiate actinomycin D action, whereas combination of decitabine and SAHA brought synergistic ROS generation and apoptotic features in CML cell line. Appropriate decrease of cell viability indicated promising therapeutic potential of this combination in CML, but side effects on normal PBL should be taken into attention.

• MeSH
• Apoptosis drug effects   MeSH
• Azacitidine analogs & derivatives   pharmacology   MeSH
• Butyrates pharmacology   MeSH
• Cytostatic Agents pharmacology   MeSH
• Dactinomycin pharmacology   MeSH
• Decitabine MeSH
• Histone Deacetylase Inhibitors pharmacology   MeSH
• Caspase 3 metabolism   MeSH
• Hydroxamic Acids pharmacology   MeSH
• Humans MeSH
• Cell Line, Tumor MeSH
• Poly(ADP-ribose) Polymerases metabolism   MeSH
• DNA Damage drug effects   MeSH
• Antineoplastic Agents pharmacology   MeSH
• Reactive Oxygen Species metabolism   MeSH
• Drug Synergism MeSH
• Vorinostat MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Azacitidine MeSH
• Butyrates MeSH
• Cytostatic Agents MeSH
• Dactinomycin MeSH
• Decitabine MeSH
• Histone Deacetylase Inhibitors MeSH
• Caspase 3 MeSH
• Hydroxamic Acids MeSH
• Poly(ADP-ribose) Polymerases MeSH
• Antineoplastic Agents MeSH
• Reactive Oxygen Species MeSH
• Vorinostat MeSH

Restoration of cellular apoptotic pathways plays a crucial role in cancer therapy strategies. In a broad spectrum of anticancer drugs, epigenetic effectors are in the center of interest mostly because of potential reversibility of their action. Methylation status of the cells is influenced by methyltransferase inhibitor 2-deoxy-5'-azacytidine (decitabine, DAC), but higher concentrations of this agent cause a DNA-damage. In our study, tumor supressor p53-apoptotic pathway was activated in decitabine-induced cell death. Expression of p53-inducible BH3-only apoptotic proteins Puma and Noxa was elevated and large activation of executive caspases was observed. The extent of acetylation in the cell is affected by histonedeacetylase inhibitor suberoylanilide hydroxamic acid (SAHA). Combination of SAHA with decitabine brought synergistic effect on apoptosis triggering in CML-T1 cell line, but apoptosis as well as necrosis occurred also in normal peripheral blood lymphocytes. Therefore, promising potential of such combined therapy calls for more detailed investigation of unwanted effects in normal cells.

• MeSH
• Apoptosis drug effects   genetics   MeSH
• Azacitidine analogs & derivatives   pharmacology   MeSH
• Leukemia, Myelogenous, Chronic, BCR-ABL Positive genetics   metabolism   pathology   MeSH
• Decitabine MeSH
• Cells, Cultured MeSH
• Hydroxamic Acids pharmacology   MeSH
• Humans MeSH
• Lymphocytes drug effects   metabolism   MeSH
• Drug Evaluation, Preclinical MeSH
• Apoptosis Regulatory Proteins genetics   metabolism   MeSH
• Antimetabolites, Antineoplastic pharmacology   MeSH
• Antineoplastic Combined Chemotherapy Protocols pharmacology   MeSH
• Proto-Oncogene Proteins c-bcl-2 genetics   metabolism   MeSH
• Proto-Oncogene Proteins genetics   metabolism   MeSH
• Gene Expression Regulation, Leukemic drug effects   MeSH
• Drug Synergism MeSH
• Up-Regulation drug effects   genetics   MeSH
• Vorinostat MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Azacitidine MeSH
• BBC3 protein, human MeSH Browser
• Decitabine MeSH
• Hydroxamic Acids MeSH
• PMAIP1 protein, human MeSH Browser
• Apoptosis Regulatory Proteins MeSH
• Antimetabolites, Antineoplastic MeSH
• Proto-Oncogene Proteins c-bcl-2 MeSH
• Proto-Oncogene Proteins MeSH
• Vorinostat MeSH