Curcumin potentiates the effect of chemotherapy against acute lymphoblastic leukemia cells via downregulation of NF-κB.

Acute lymphoblastic leukemia (ALL) accounts for 30% of all pediatric cancers. Currently available treatments exhibit toxicity and certain patients may develop resistance. Thus, less toxic and chemoresistance-reversal agents are required. In the present study, the potential effect of curcumin, a component of Curcuma longa, as a pharmacological co-adjuvant of several chemotherapeutic agents against ALL, including prednisone, 6-mercaptopurine, dexamethasone, cyclophosphamide, l-asparaginase, vincristine, daunorubicin, doxorubicin, methotrexate and cytarabine, was investigated in the REH ALL cell line cultures treated in combination with chemotherapeutic agents and curcumin. The results of cell viability, gene expression and activation of NF-κB and caspase 3 indicated that curcumin potentiates the anticancer effects of the aforementioned chemotherapeutic agents in the REH ALL cell line. Following treatment with the above chemotherapeutic agents, curcumin enhanced caspase-3 activation and downregulated nuclear factor-kappa B (NF-κB) activation. Curcumin also downregulated the oxidative stress induced by certain chemotherapies. Notably, curcumin did not affect the gene expression of cell survival proteins such as B-cell lymphoma (Bcl)-2, Bcl-extra large, survivin, c-Myc and cyclin D1, which are regulated by the NF-κB transcription factor. In conclusion, curcumin has the potential to improve the effect of chemotherapeutic agents against ALL.