I-kappa-kinase-2 (IKK-2) Inhibition Potentiates Vincristine Cytotoxicity in Non-Hodgkin's Lymphoma
Overview
Oncology
Authors
Affiliations
Background: IKK-2 is an important regulator of the nuclear factor-κB (NF-κB) which has been implicated in survival, proliferation and apoptosis resistance of lymphoma cells. In this study, we investigated whether inhibition of IKK-2 impacts cell growth or cytotoxicity of selected conventional chemotherapeutic agents in non-Hodgkin's lymphoma.Two established model systems were used; Follicular (WSU-FSCCL) and Diffuse Large Cell (WSU-DLCL2) Lymphoma, both of which constitutively express p-IκB. A novel, selective small molecule inhibitor of IKK-2, ML120B (N-[6-chloro-7-methoxy-9H-β-carbolin-8-yl]-2-methylnicotinamide) was used to perturb NF-κB in lymphoma cells. The growth inhibitory effect of ML120B (M) alone and in combination with cyclophosphamide monohydrate (C), doxorubicin (H) or vincristine (V) was evaluated in vitro using short-term culture assay. We also determined efficacy of the combination in vivo using the SCID mouse xenografts.
Results: ML120B down-regulated p-IκBα protein expression in a concentration dependent manner, caused growth inhibition, increased G0/G1 cells, but did not induce apoptosis. There was no significant enhancement of cell kill in the M/C or M/H combination. However, there was strong synergy in the M/V combination where the vincristine concentration can be lowered by a hundred fold in the combination for comparable G2/M arrest and apoptosis. ML120B prevented vincristine-induced nuclear translocation of p65 subunit of NF-κB. In vivo, ML120B was effective by itself and enhanced CHOP anti-tumor activity significantly (P = 0.001) in the WSU-DLCL2-SCID model but did not prevent CNS lymphoma in the WSU-FSCCL-SCID model.
Conclusions: For the first time, this study demonstrates that perturbation of IKK-2 by ML120B leads to synergistic enhancement of vincristine cytotoxicity in lymphoma. These results suggest that disruption of the NF-κB pathway is a useful adjunct to cytotoxic chemotherapy in lymphoma.
Arumov A, Liyanage P, Trabolsi A, Roberts E, Li L, Ferreira B Cancer Res. 2020; 81(3):763-775.
PMID: 33177062 PMC: 9177130. DOI: 10.1158/0008-5472.CAN-20-2674.
Tong H, Huang Z, Chen H, Zhou B, Liao Y, Wang Z Onco Targets Ther. 2020; 13:9839-9848.
PMID: 33061461 PMC: 7537840. DOI: 10.2147/OTT.S253691.
Prescott J, Cook S Cells. 2018; 7(9).
PMID: 30142927 PMC: 6162708. DOI: 10.3390/cells7090115.
Pimentel-Gutierrez H, Bobadilla-Morales L, Barba-Barba C, Ortega-de-la-Torre C, Sanchez-Zubieta F, Corona-Rivera J Oncol Lett. 2016; 12(5):4117-4124.
PMID: 27895780 PMC: 5104245. DOI: 10.3892/ol.2016.5217.
Interleukin-9 promotes cell survival and drug resistance in diffuse large B-cell lymphoma.
Lv X, Feng L, Ge X, Lu K, Wang X J Exp Clin Cancer Res. 2016; 35(1):106.
PMID: 27364124 PMC: 4929715. DOI: 10.1186/s13046-016-0374-3.