Abstract:

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.

Key words: Breast neoplasms, Bone metastasis, Osteoprotegerin, MDA-MB-231 cell line