目的

观察抑制肿瘤细胞骨保护素(osteoprotegerin,OPG)表达对乳腺癌MDA-MB-231细胞株致骨转移的影响。

方法

32只4～6周龄雌性裸鼠被随机分为A、B、C、D 4组,每组8只,A、C 组的每只裸鼠按分组分别以5×10⁵ 个MDA-MB-231细胞注射入左心室(A 组)或左胫骨骨髓腔(C组)。B、D 组的每只裸鼠按分组分别以5×10⁵ 个MDA-MB-231i细胞(OPG 表达抑制)注射入左心室(B组)或左胫骨骨髓腔(D 组),42 d后行病理检查,比较A、B组骨转移发生率和骨转移灶数量,以及C、D组的骨肿瘤体积。定量资料的比较采用t检验或秩和检验,定性资料比较采用Fisher确切概率检验。

结果

A组有6只发生骨转移,全组共检出不连续性骨转移灶23处;B组有3只发生骨转移,全组共检出不连续性骨转移灶8处。A 组的骨转移发生率和转移灶数量虽高于B 组,但两者差异并无统计学意义(P＞0.05)。C 组肿瘤平均体积为(66.29±41.01)mm³,D 组肿瘤平均体积为(23.70±16.14)mm³,C组骨肿瘤体积大于D 组,两组间差异有统计学意义(P=0.02)。

结论

乳腺癌细胞致骨转移能力与其OPG 表达水平密切相关,抑制OPG 表达可以降低乳腺癌细胞致骨转移的能力。

Objective

To investigate the impact of inhibiting osteoprotegerin(OPG)expression in tumor cells on breast cancer cell line MDA-MB-231 induced bone metastasis.

Methods

Thirty-two female nude mice aged 4-6 weeks were divided randomly into four groups(n=8 in each group).MDA-MB-231 cells(5×10⁵)were injected into the body via the left heart ventricles(group A)and via the left tibia marrow cavities (group C),respectively.MDA-MB-231i cells (5×10⁵)(OPG expression inhibition)were injected into the body via the left heart ventricles(group B)and via the left tibia marrow cavities(group D),respectively.Forty-two days after the injection,all the nude mice were subjected to pathological examination to determine bone metastasis.Student's t-test was used for the comparison of quantitative data,and Fisher's exact test was used for the comparison of qualitative data.

Results

There were 23 bone metastasis lesions detected and six mice with bone metastasis in group A,and 8 bone metastasis lesions detected and three mice with bone metastasis in group B,but with no statistically significant difference between the two groups(P＞0.05).The bone tumor volume of group C and group D was(66.29±41.01)mm³ and(23.70±16.14)mm³,respectively.The bone tumor volume of group C was larger than that of group D.There was a statistically significant difference in the bone tumor volume between group C and group D (P=0.02).

Conclusions

Breast cancer metastasis to bone is closely correlated with the osteoprotegerin expression level in tumor cells.To inhibit the osteoprotegerin expression can decrease the capability of breast cancer-induced bone metastasis.