蟾蜍令灵对裸鼠食管鳞癌原位移植瘤中 P70S6K 表达的影响

摘要

Background Esophageal cancer is one of the most common gastrointestinal malignant tumors in the world. According to related studies in recent years,P70S6K is closely related to the occurrence of esophageal cancer. Some previous studies indicate that Bufalin has significant anti - tumor effect. Objectjve To investigate the effects of Bufalin on P70S6K in orthotopic transplanted tumor of esophageal squamous cell carcinoma in nude mice. Methods 36 Nu/ Nu healthy nude mice(18 were male,and 18 were female)were euqally divided into four groups by random number table method:control group (treated with 0. 9% sodium chloride solution),Bufalin low dose group(BL group,treated with 0. 5 mg/ kg Bufalin),Bufalin middle dose group( BM group,treated with 1. 0 mg/ kg Bufalin)and Bufalin high dose group( BH group,treated with 1. 5 mg/ kg Bufalin). The growth of xenografted tumors after Bufalin treatment was observed;the expression of P70S6K mRNA in transplanted tumor in nude mice was examined by RT - PCR method;the expression level of P70S6K and activation level of P70S6K in transplanted tumors of nude mice were detected by western blot and immunohistochemical methods. Results There was no significant difference in body weight of nude mice among four groups before treatment and one day after treatment(P >0. 05). There was no significant difference in tumor volume among four groups before treatment( P > 0. 05 );there was significant difference in tumor volume among four groups 15 days after treatment(P < 0. 05). Tumor volume of mice in BM group and BH group was significantly lower than that of mice in BL group and control group 15 days after treatment,respectively(P <0. 05). There was significant difference in tumor inhibition ratio among three groups( P < 0. 05). There was no significant difference in relative expression levels of P70S6K mRNA and P70S6K among four groups(F = 0. 634,P > 0. 05). There was no significant difference in relative expression level of p - P70S6K among four groups( F = 233. 005,P < 0. 05). Conclusjon Bufalin has an anti - tumor effect on the orthotopic transplanted tumor of esophageal squamous cell carcinoma in nude mice;Bufalin can decrease the level of P70S6K phosphorylation,while P70S6K is not affected,which suggests that Bufalin may inhibit tumor growth through inhibiting the activation of P70S6K.%背景食管癌是世界上最常见的消化道恶性肿瘤之一，近年研究发现，核糖体蛋白 S6激酶（P70S6K）与其发生密切相关。笔者前期的研究表明，蟾蜍令灵（Bufalin）有明显的抗肿瘤作用。目的探讨 Bufalin 对裸鼠食管鳞癌原位移植瘤中 P70S6K 表达的影响。方法 Nu/ Nu 健康裸鼠36只，雌雄各半，采用随机数字表法分为4组，每组9只，即对照组（0.9%氯化钠溶液）、Bufalin 低剂量（0.5 mg/ kg，BL）组、Bufalin 中剂量（1.0 mg/ kg，BM）组、Bufalin 高剂量（1.5 mg/ kg，BH）组。观察经 Bufalin 治疗后裸鼠肿瘤生长情况；反转录 PCR（RT - PCR）法检测裸鼠原位移植瘤中 P70S6K mRNA 的表达，Western blotting 及免疫组化法检测裸鼠原位移植瘤中 P70S6K 和p - P70S6K相对表达量。结果4组治疗前及治疗后第1天裸鼠体质量比较，差异无统计学意义（P >0.05）。4组治疗前肿瘤体积比较，差异无统计学意义（P >0.05）；治疗后第15天肿瘤体积比较，差异有统计学意义（P <0.05）。治疗后第15天，BM组、BH 组肿瘤体积均低于 BL 组和对照组（P <0.05）。3组肿瘤抑制率比较，差异有统计学意义（ P <0.05）。4组P70S6K mRNA 及 P70S6K 相对表达量比较，差异无统计学意义（F =0.634、0.119，P >0.05）。4组p - P70S6K相对表达量比较，差异有统计学意义（F =233.005，P <0.05）。结论 Bufalin 对裸鼠食管鳞癌原位移植瘤具有抑制作用；Bufalin 可以下调 P70S6K 的磷酸化水平，而 P70S6K 则不受影响，提示 Bufalin 可能通过抑制 P70S6K 活化而发挥作用。