易普利姆玛通过抑制TGF-β1/ERK信号通路影响肺癌小鼠移植瘤组织中T淋巴细胞及Bcl-2 mRNA表达

Ipilimumab affects T lymphocytes and Bcl-2 mRNA expression in xenograft tissues of lung cancer-bearing mice by inhibiting TGF-β1/ERK signaling pathway

目的:研究易普利姆玛(ipilimumab)通过抑制TGF-β1/ERK信号通路对肺癌小鼠T淋巴细胞、Bcl-2 mRNA表达的影响。方法:将45只接种肺癌细胞Lewis的C57BL/6小鼠随机分为对照组、低剂量组、高剂量组,每组15只,其中低剂量组给予3mg/kg易普利姆玛,高剂量组给予5 mg/kg易普利姆玛,对照组给予同体积的0.9%氯化钠溶液。通过WB、q PCR检测易普利姆玛处理对TGF-β1/ERK信号通路、Bcl-2 m RNA表达的影响,以及对免疫功能改善和移植瘤的抑制情况。结果:给予易普利姆玛后,低剂量组、高剂量组小鼠的瘤质量、体积显著低于空白对照组,且随着剂量的增加抑瘤率也增加(P<0.05);小鼠的胸腺系数和脾脏系数显著高于空白对照组,且随着剂量的增加,该系数也增加(P<0.05)。高、低剂量组小鼠给药后CD3^+、CD4^+、CD4^+/CD8^+细胞水平显著增加,且显著高于对照组,其中高剂量组给药后各水平显著高于低剂量组(P<0.05)。高、低剂量组小鼠给药后血清炎症因子水平显著增加,均显著低于对照组,且高剂量组血清TNF-α、IL-6、IL-3水平显著低于低剂量组(均P<0.05)。高、低剂量组小鼠给药后肿瘤组织中的TGF-β1、ERK1/2、p-ERK1/2、MEK表达量显著降低,高剂量组各蛋白水平显著低于低剂量组(P<0.05),且高剂量组TGF-β1表达阳性率最低(P<0.05)。高、低剂量组小鼠给药后肿瘤组织中的Bcl-2 mRNA表达量显著降低,高剂量组表达水平显著低于低剂量组(P<0.05)。结论:易普利姆玛可有效抑制TGF-β1/ERK信号通路、改善机体免疫功能以及下调Bcl-2的表达,从而抑制小鼠体内肺癌细胞Lewis生长,发挥抗肿瘤作用。

Objective: To study the effect of ipilimumab on T lymphocytes and Bcl-2 mRNA expression in lung cancer-bearing mice by inhibiting TGF-β1/ERK signaling pathway. Methods: Forty-five C57 mices inoculated with Lewis lung cancer cells were randomly divided into control group, low dose ipilimumab group and high dose ipilimumab group with 15 mice in each. The low and high dose groups were given 3 mg/kg and 5 mg/kg ipilimumab respectively, while the control group was given 0.9% sodium chloride solution with the same volume. The effects of ipilimumab on TGF-β1/ERK signaling pathway, Bcl-2 mRNA expression, immune function improvement and tumor inhibition in three groups were detected by WB and qPCR. Results: After administration of ipilimumab, the tumor weight and volume of mice in low-dose and high-dose groups were significantly lower than that of the control group, and the tumor inhibition rate increased in a dose-dependent manner(P<0.05). The thymus index and spleen index of mice were significantly higher than that of control group, which also increased in a dose-dependent manner(P<0.05). The levels of CD3^+, CD4^+, CD4^+/CD8^+cells in the high and low dose groups were significantly higher than those in the control group, with significantly higher levels in high dose group compared with the low dose group(P<0.05). The levels of serum inflammatory factors were significantly lower than those in control group, and the levels of serum TNF-α, IL-6 and IL-3 in the high dose group were significantly lower than those in the low dose group(P<0.05). The expressions of TGF-β1, ERK1/2, p-ERK1/2 and MEK in tumor tissues of both high and low dose groups significantly decreased, with more lower levels in high dose group than in low dose groups(all P<0.05), and the positive rate of TGF-β1 expression in high dose group was the lowest. The m RNA expression of Bcl-2 in tumor tissues of high and low dose groups decreased significantly after drug administration, with a significantly lower level in high does group than that in low dose group(P<0.05). Conclusion: Ipilimumab can effectively inhibit TGF-β1/ERK signaling pathway, improve immune function and down-regulate the expression of Bcl-2, thus inhibit the growth of Lewis lung cancer cells and play an antitumor role in mice.