人参皂甙Rg3和核糖核酸酶抑制因子转基因对小鼠黑色素瘤的抑制作用研究

Inhibitory effect of ginsenoside-Rg3 on lung metastasis of mouse melanoma transfected with ribonuclease inhibitor

目的观察人参皂甙Rg3和核糖核酸酶抑制因子(RI)转基因对小鼠B16黑色素瘤肺转移的抑制作用和影响,探讨人参皂甙Rg3和RI抗肿瘤生长和转移作用的分子机制。方法制备转RI基因的B16黑色素瘤肺转移小鼠模型,对野生型对照组(W组)、空质粒转染组(B组)和RI转基因组(RI组)以及给予Rg3的野生型对照组(Rg3/W组)、空质粒转染组(Rg3/B组)和RI转基因组(Rg3/RI组)中,荷瘤小鼠肺重量、肿瘤转移灶数目、生存期和肿瘤组织微血管密度进行检测和分析。结果Rg3和RI转基因使荷瘤小鼠肺重量降低,肿瘤转移灶数目减少,其肺重量降低和肿瘤转移灶数目减少的程度以Rg3/RI组最明显,Rg3/B组、Rg3/W组和RI组次之,与W组和B组差异有显著性(P<0.01),Rg3和RI有一定的协同性。Rg3和RI可延长荷瘤小鼠的生存期,Rg3/RI组小鼠在观察期(1.5个月)内均存活,W组和B组小鼠全部死亡(至26d),且出现死亡的时间较早。经HE染色和第Ⅷ因子相关抗原的免疫组化分析显示,Rg3和RI使肺内瘤组织的微血管密度降低,降低的程度为Rg3/RI组>Rg3/B组>Rg3/W组>RI组>B组>W组。结论人参皂甙Rg3可增强RI转基因对小鼠黑色素瘤肺转移的抑制作用,人参皂甙Rg3和RI基因在抗肿瘤生长、转移及血管生成方面有协同作用。

Objective To investigate the effect of ginsenoside-Rg3 on lung metastasis of ribonuclease inhibitor (RI) gene-transfected mouse B16 melanoma. Methods C57BL/6 mice were iv injected with parental or RI-transfected B16 melanoma cells. Lung metastasis was assessed by the number of surface tumor nodules. Mice were divided into 6 groups. Group Ⅰ, Ⅱ and Ⅲ of mice were given parental, mock-transfected and RI-transfected B16 melanoma cells, respectively while in group IV, V and VI, Rg3 (1.5 mg/kg, iv q.o.d. x 10) was given to mice bearing parental, mock-transfected and RI-transfected B16 melanoma, respectively. Micovessel density (MVD) of the lung metastatic tumor was assessed by immunohistochemical staining of factor Ⅷ-R expression. Results The number of tumor nodules was significantly decreased in mice injected with RI-transfected B16 melanoma (Gp Ⅲ, compared to Gp Ⅰ and Ⅱ). Rg3 treament per se could also decrease the number of lung tumor nodules but to a lesser extent (Gp IV and V compared to Gp Ⅲ). However, Rg3 synergized with RI transfection resulting in most significant inhibition of lung metastasis (Gp VI). Mice in Gp Ⅰ and Ⅱ died within 26 days of the experiment, whereas all the mice in Gp VI were alive during the observation period of one and one half month. MVD was significantly decreased in the lung tumor nodules in mice injected with RI-transfected B16 melanoma. It was further decreased when additional Rg3 was given (Gp VI). Conclusion Transfection of ribonuclease inhibitor gene significantly reduces the metastatic potential of B16 melanoma. Ginsenoside-Rg3 has a synergistic effect.