title: Curcumin enhances the cytogenotoxic effect of etoposide in leukemia cells through induction of reactive oxygen species.
abstract: Curcumin may exert a more selective cytotoxic effect in tumor cells with elevated levels of free radicals. Here, we investigated whether curcumin can modulate etoposide action in myeloid leukemia cells and in normal cells of hematopoietic origin. HL-60 cell line, normal myeloid progenitor cluster of differentiation (CD)-34(+) cells, and granulocytes were incubated for 4 or 24 hours at different concentrations of curcumin and/or etoposide. Brown Norway rats with acute myeloid leukemia (BNML) were used to prove the influence of curcumin on etoposide action in vivo. Rats were treated with curcumin for 23 days and etoposide was administered for the final 3 days of the experiment. Curcumin synergistically potentiated the cytotoxic effect of etoposide, and it intensified apoptosis and phosphorylation of the histone H2AX induced by this cytostatic drug in leukemic HL-60 cells. In contrast, curcumin did not significantly modify etoposide-induced cytotoxicity and H2AX phosphorylation in normal CD34(+) cells and granulocytes. Curcumin modified the cytotoxic action of etoposide in HL-60 cells through intensification of free radical production because preincubation with N-acetyl-l-cysteine (NAC) significantly reduced the cytotoxic effect of curcumin itself and a combination of two compounds. In contrast, NAC did not decrease the cytotoxic effect of etoposide. Thus, oxidative stress plays a greater role in the cytotoxic effect of curcumin than that of etoposide in HL-60 cells. In vitro results were confirmed in a BNML model. Pretreatment with curcumin enhanced the antileukemic activity of etoposide in BNML rats (1.57-fold tumor reduction versus etoposide alone; P<0.05) and induced apoptosis of BNML cells more efficiently than etoposide alone (1.54-fold change versus etoposide alone; P<0.05), but this treatment protected nonleukemic B-cells from apoptosis. Thus, curcumin can increase the antileukemic effect of etoposide through reactive oxygen species in sensitive myeloid leukemia cells, and it is harmless to normal human cells.
authors.affiliation: Department of Cytobiology, Jagiellonian University Medical College, Krakow, Poland.
authors.forename: Monika A
authors.initials: MA
authors.lastname: Papież
authors.affiliation: Department of Medical Diagnostic, Faculty of Pharmacy, Jagiellonian University Medical College, Krakow, Poland.
authors.forename: Wirginia
authors.initials: W
authors.lastname: Krzyściak
authors.affiliation: Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Szade
authors.affiliation: Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland; Department of Clinical Immunology, Institute of Pediatrics, Krakow, Poland.
authors.forename: Karolina
authors.initials: K
authors.lastname: Bukowska-Straková
authors.affiliation: Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Kozakowska
authors.affiliation: Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland.
authors.forename: Karolina
authors.initials: K
authors.lastname: Hajduk
authors.affiliation: Department of Toxicology, Faculty of Pharmacy, Jagiellonian University Medical College, Krakow, Poland.
authors.forename: Beata
authors.initials: B
authors.lastname: Bystrowska
authors.affiliation: Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland; Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland.
authors.forename: Jozef
authors.initials: J
authors.lastname: Dulak
authors.affiliation: Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland.
authors.forename: Alicja
authors.initials: A
authors.lastname: Jozkowicz
mesh_terms: D000328:Adult; D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D003474:Curcumin / Q000494:pharmacology*; D005047:Etoposide / Q000494:pharmacology*; D005260:Female; D018922:HL-60 Cells; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins / Q000032:analysis; D015470:Leukemia, Myeloid, Acute / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D016328:NF-kappa B / Q000032:analysis; D018384:Oxidative Stress / Q000187:drug effects; D051381:Rats; D011914:Rats, Inbred BN; D017382:Reactive Oxygen Species / Q000378:metabolism*; D000077022:Survivin
chemical_list: D000972:Antineoplastic Agents, Phytogenic; C107489:BIRC5 protein, human; D051034:Inhibitor of Apoptosis Proteins; D016328:NF-kappa B; D017382:Reactive Oxygen Species; D000077022:Survivin; D005047:Etoposide; D003474:Curcumin
keywords: ROS; acute myeloid leukemia; apoptosis; curcumin; etoposide; γ-H2AX