核因子-κB在癌性恶病质形成中的作用

目的研究核因子(NF)-κB和促炎细胞因子在癌性恶病质形成中的作用以及吲哚美辛(IND)对其调控作用.方法 30只雄性BALB/c小鼠随机分为5组A组为对照组,B组为荷瘤加生理盐水组,C组为荷瘤加IND(0.25 mg/kg)组,D组为荷瘤加IND (0.5 mg/kg)组;E组为荷瘤加 IND (2.0 mg/kg)组.利用鼠结肠腺癌26细胞株皮下接种诱导癌性恶病质.恶病质出现后,皮下分别给予生理盐水以及不同剂量IND.1周后检测动物血清肿瘤坏死因子-α(TNF-α)和白细胞介素(IL-6)浓度和脾脏中NF-κB活性.整个实验过程中跟踪监测动物体重以及腓肠肌重量改变.结果所有接种动物均出现恶病质,食物摄入量组间无明显差异.第16天B组体重为A组的82.0% (P<0.01),腓肠肌重量下降了28.7% (P<0.01),血清TNF-α和IL-6浓度显著升高(P<0.01).0.5 mg/kg的IND腓肠肌重量显著增加(P<0.01),血清TNF-α(P<0.05)和IL-6水平降低(P<0.01).凝胶电泳迁移率分析显示B组小鼠脾脏NF-κB活性较A组显著增加(P<0.01), IND降低NF-κB活性,在0.5 mg/kg剂量组最为显著(P<0.01).且脾脏NF-κB活性与细胞因子浓度呈正线性相关(rTNF-α=0.918, PTNF-α=0.028;rIL-6=0.884, PIL-6=0.046).结论癌性恶病质的产生与受NF-κB调控的细胞因子TNF-α和IL-6水平相关.IND可以降低NF-κB活性和细胞因子水平,缓解恶病质症状.

Role of NF-kappa B in cancer cachexia

OBJECTIVE: To assess the putative involvement of NF-kappaB and pro-inflammatory cytokines in the pathogenesis of cancer cachexia and the therapeutic efficacy of indomethacin (IND) on cachexia. METHODS: Thirty young male BALB/c mice were divided randomly into five groups: A, control; B, tumor-bearing plus saline; C, tumor-bearing plus IND (0.25 mg/kg); D, tumor-bearing plus IND (0.5 mg/kg); and E, tumor-bearing plus IND (2.0 mg/kg). Colon 26 adenocarcinoma cells of murine were inoculated subcutaneously to induce cachexia. Saline and IND were given intraperitoneally daily for 7 days from the onset of cachexia to sacrifice. Food intake and body composition were documented, serum TNF-alpha and IL-6 levels and activity of NF-kappaB in spleen were investigated in all animals. RESULTS: Cachexia was observed in all tumor-bearing mice. No difference was found between groups in food intake (P > 0.05). By day 16, body weights of non-tumor mice were about 82.0% of healthy controls (P < 0.01), and the weight of gastrocnemius was decreased by 28.7% (P < 0.01). Gastrocnemius weight was increased markedly (P < 0.01) after treatment of IND (0.5 mg/kg). Tumor-bearing caused a significant increase in serum TNF-alpha and IL-6 levels (P < 0.01). The concentration of TNF-alpha (P < 0.05) and IL-6 (P < 0.01) in tumor-bearing mice was reduced after administration of 0.5 mg/kg IND for 7 days. NF-kappaB activation in the spleen was increased in tumor-bearing mice in comparison with controls. NF-kappaB activity was reduced in mice treated with IND. The maximal inhibition was observed at an dosage of 0.5 mg/kg (P < 0.01). Liner positive correlation was found between NF-kappaB activity and cytokine levels (r(TNF-alpha) = 0.918, P(TNF-alpha) = 0.028; r(IL-6) = 0.884, P(IL-6) = 0.046). CONCLUSIONS: Cachexia induced by colon 26 adenocarcinoma cells may be partially attributed to the enhanced TNF-alpha and IL-6 levels which is controlled by NF-kappaB. IND may inhibit the activation of NF-kappaB, decrease serum TNF-alpha and IL-6 levels and thus alleviate the cachexia.