Voboril Rene, Hochwald Steven N, Li Jing, Brank Adam, Weberova Jana, Wessels Frank, Moldawer Lyle L, Camp E Ramsay, MacKay Sally L D
Department of Surgery, Division of Surgical Oncology, University of Florida College of Medicine, 1600 SW Archer Road, Room 6184, Gainesville, FL 32610, USA.
J Surg Res. 2004 Aug;120(2):178-88. doi: 10.1016/j.jss.2003.11.023.
5-fluorouracil (5-FU), the most common antimetabolite used for the treatment of colorectal cancer, exerts its cytotoxic effects through the induction of apoptosis. Folinic acid potentiates the effect of 5-FU. Drug activity is currently limited as a result of inducible chemoresistance. Limited research suggests that the transcription factor nuclear factor kappa-B (NF-kappaB), which has antiapoptotic properties, may play a major role in inducible chemoresistance.
SW48 colon cancer cells were used for all experiments. Cell growth was determined by cell proliferation assay. Apoptosis was assessed by measuring caspase 3 activity. Activation of NF-kappaB was ascertained by electrophoretic mobility shift assay, luciferase reporter assay, and Western blot analysis.
Treatment with 5-FU (0.001-10 mm), not only inhibited growth and induced apoptosis but significantly activated NF-kappaB in SW48 cells. Folinic acid alone (0.01-100 mg/L) did not inhibit growth but improved the cytotoxic effect of 5-FU in a dose-dependent manner. Likewise, folinic acid alone did not activate NF-kappaB or induce apoptosis but enhanced 5-FU-mediated NF-kappaB activation and cell apoptosis. Transfection with adenovirus IkappaBalpha super-repressor strongly inhibited constitutive activation of NF-kappaB and significantly enhanced 5-FU and 5-FU/Folinic acid-mediated growth inhibition (P < 0.05).
Treatment with 5-FU activates NF-kappaB. Folinic acid enhances 5-FU-mediated activation of NF-kappaB. Inhibition of NF-kappaB enhances the cytotoxic effect of 5-FU with or without Folinic acid in colon cancer cells.
5-氟尿嘧啶(5-FU)是治疗结直肠癌最常用的抗代谢药物,通过诱导细胞凋亡发挥其细胞毒性作用。亚叶酸可增强5-FU的作用。由于可诱导的化疗耐药性,目前药物活性受到限制。有限的研究表明,具有抗凋亡特性的转录因子核因子κB(NF-κB)可能在诱导化疗耐药中起主要作用。
所有实验均使用SW48结肠癌细胞。通过细胞增殖试验测定细胞生长情况。通过测量半胱天冬酶3活性评估细胞凋亡。通过电泳迁移率变动分析、荧光素酶报告基因分析和蛋白质免疫印迹分析确定NF-κB的激活情况。
用5-FU(0.001-10 mM)处理,不仅抑制了SW48细胞的生长并诱导其凋亡,还显著激活了NF-κB。单独使用亚叶酸(0.01-100 mg/L)不会抑制生长,但以剂量依赖的方式增强了5-FU的细胞毒性作用。同样,单独使用亚叶酸不会激活NF-κB或诱导凋亡,但增强了5-FU介导的NF-κB激活和细胞凋亡。用腺病毒IκBα超级抑制剂转染可强烈抑制NF-κB 的组成性激活,并显著增强5-FU和5-FU/亚叶酸介导的生长抑制作用(P < 0.05)。
5-FU处理可激活NF-κB。亚叶酸增强5-FU介导的NF-κB激活。抑制NF-κB可增强5-FU在有或没有亚叶酸存在时对结肠癌细胞的细胞毒性作用。