2-甲氧基雌二醇对恶性黑素瘤种植性肿瘤的体内抑制作用

Inhibition effects of 2-methoxyestradiol on melanoma xenograft tumor in vivo

目的探讨2-甲氧基雌二醇(2-methoxyestradiol,2-ME)对恶性黑素瘤(malignant melanoma,MM)细胞在小鼠体内生长的抑制作用。方法应用噻唑蓝[3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide,MTT]方法检测2-ME对黑素瘤B16细胞的抑制作用。构建BALB/c小鼠的恶性黑素瘤细胞种植性肿瘤模型,分为3组,每组6只。治疗组(2-ME组)每只小鼠尾静脉注射50 mg/kg 2-ME,阳性药物组[环磷酰胺(cyclophosphamide,CTX)组]每只小鼠尾静脉注射20mg/kg CTX,阴性对照组(Nacl组)注射相同体积的生理盐水,2d/次,共14d,每3d测量肿瘤体积,实验结束后称量肿瘤质量;免疫组织化学(immunohistochemistry,IHC)方法对肿瘤组织Gadd45b和C-myc蛋白的表达变化进行分析,HE染色对治疗组和阴性对照组小鼠的肿瘤组织、肺组织、肝组织和脾组织进行形态分析。结果 2-ME对黑素瘤B16细胞具有明显的抑制作用,且对B16细胞的抑制作用呈时间和剂量依赖性。CTX组和2-ME组肿瘤体积和肿瘤质量均小于Nacl组(P<0.01),但CTX组与2-ME组之间肿瘤体积和肿瘤质量差异无统计学意义(P>0.05)。IHC实验结果表明,与对照组相比,2-ME组小鼠肿瘤组织中C-myc蛋白表达水平明显升高,Gadd45b蛋白表达水平明显降低。HE染色结果显示,2-ME组小鼠和对照组小鼠的肝及脾均无明显的组织形态改变,而3/6的对照组小鼠发生肺组织转移,2-ME组肺脏无明显改变。结论2-ME对黑素瘤B16荷瘤小鼠的肿瘤生长具有抑制作用,其机制可能与调节C-myc和Gadd45b基因表达有关。

Objective To study the inhibition effects of 2-methoxyestradiol（2-ME）on malignant melanoma（MM）cells in BALB/c mice xenograft tumor.Methods The inhibition effects of 2-ME on MM cells were measured by 3-（4,5-Dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide（MTT）.Building BALB/c mice xenograft tumor model,BALB/c mice were divided into three groups with six mice in each group.Treatment group and negative control group were treated with 2-ME（50mg/kg）and equally volume normal saline respectively every two days,for a 14-days duration and calculated the average volume every three days.Positive drug group were treated with CTX（20 mg/kg）.After experiment ended,the tumor weight were calculated.The expression levels of C-myc and Gadd45 bin tumor were detected by immunohistochemical.Morphological changes of tumor tissue,lung,liver and spleen tissues were observed by HE staining.Results 2-ME had obvious inhibitory effect on melanoma cells and the inhibitory effect in a dose-time dependent manner.Compared with the Nacl group,the volume and weight of tumor tissues in CTX group and 2-ME group were reduced remarkably（P〈0.01）,but there w as no statistical signifieance between the CTX group and the 2-ME group（P〉0.05）.Comparing to control group,the expression levels of C-myc were decreased,while Gadd45 bwere increased.No obvious morphological changes were found in liver and spleen tissues in treatment group and in control group,but there were lung metastasis in 3 of 6 mice.Conclusion 2-ME had inhibitory effect on BALB/c mice xenograft tumor,and the mechanism may be related to modulating gadd45 band C-myc genes expression.