Weldon C B, Burow M E, Rolfe K W, Clayton J L, Jaffe B M, Beckman B S
Department of Surgery, Tulane/Xavier Center for Bioenvironmental Research, Tulane University Health Sciences Center, New Orleans, LA 70112, USA.
Surgery. 2001 Aug;130(2):143-50. doi: 10.1067/msy.2001.115512.
Nuclear factor-kappa B (NF-kappa B) is a known survival pathway, and it may explain differential sensitivity to tumor necrosis factor-alpha (TNF-alpha) and chemotherapeutic-induced apoptosis in apoptotically sensitive (APO+) and apoptotically resistant (APO-) Michigan Cancer Foundation-7 breast cancer cells.
Crystal violet viability and luciferase reporter gene assays were used to determine the inhibitory concentration of viability at 50% (IC(50)) and the inhibitory concentration of activity at 50% (EC(50)) values in APO- and APO+ cells with the selective NF-kappa B inhibitor, BAY 11-7082 (BAY). The apoptotic reporter assay was used to determine the effects of the transfection of the inhibitory kappa B-dominant negative (I kappa B-DN) construct in conjunction with TNF, paclitaxel, or doxorubicin treatments in these cells.
The concentrations at which 50% of cell viability is inhibited (IC(50)) and at which 50% of NF-kappa B activity is inhibited (EC(50)) for BAY in APO- and APO+ cells were 95.24 micromol/L and 1.53 micromol/L, respectively, and 7.62 micromol/L and 2.64 micromol/L, respectively. The IC(50) and the EC(50) values were equivalent for the APO+ cells (P =.665), but not for the APO- cells (P =.025). I kappa B-DN--transfection alone, or with TNF, doxorubicin, or paclitaxel treatments resulted in cell death of both APO- and APO+ cells as compared with vector-control; however, greater cytotoxicity was seen in the APO+ cells. Direct comparison of the APO+ cells versus the APO- cells revealed that these differences were significant (P =.05).
Pharmacologic or molecular inhibition of the NF-kappa B pathway blocked cell survival in MCF-7 APO+ cells, while only molecular inhibition induced cytotoxicity in the APO- cells. Selective manipulation of the NF-kappa B pathway in combination with standard chemotherapeutic agents may lead to an increased potency and efficacy of these agents.
核因子-κB（NF-κB）是一种已知的生存途径，它可能解释了密歇根癌症基金会-7乳腺癌细胞中凋亡敏感（APO+）和凋亡抵抗（APO-）细胞对肿瘤坏死因子-α（TNF-α）和化疗诱导凋亡的不同敏感性。
使用结晶紫活力和荧光素酶报告基因测定法，用选择性NF-κB抑制剂BAY 11-7082（BAY）测定APO-和APO+细胞中50%活力抑制浓度（IC(50)）和50%活性抑制浓度（EC(50)）值。凋亡报告基因测定法用于确定在这些细胞中，与TNF、紫杉醇或阿霉素处理联合转染抑制性κB显性阴性（IκB-DN）构建体的效果。
BAY在APO-和APO+细胞中50%细胞活力被抑制时的浓度（IC(50)）和50% NF-κB活性被抑制时的浓度（EC(50)）分别为95.24 μmol/L和1.53 μmol/L，以及7.62 μmol/L和2.64 μmol/L。APO+细胞的IC(50)和EC(50)值相等（P = 0.665），但APO-细胞不相等（P = 0.025）。与载体对照相比，单独转染IκB-DN或与TNF、阿霉素或紫杉醇处理联合转染均导致APO-和APO+细胞死亡；然而，APO+细胞中观察到更大的细胞毒性。APO+细胞与APO-细胞的直接比较显示这些差异具有显著性（P = 0.05）。
NF-κB途径的药理学或分子抑制可阻断MCF-7 APO+细胞的存活，而仅分子抑制可诱导APO-细胞的细胞毒性。NF-κB途径的选择性调控与标准化疗药物联合使用可能会提高这些药物的效力和疗效。
