Expression of CXCL12 and its receptor CXCR7 in breast carcinoma with bone metastasis and their significance

Purpose To examine the expression of chemokine CXCL12 and its receptor CXCR7 in breast carcinoma,and to evaluate the relationship between their expression and the clinicopatholog factors,as well as bone metastasis.Methods CXCL12 and CXCR7 were detected by RT-PCR and immunohistochemistry and tissue microarrays in normal breast tissue and breast carcinoma tissue.Their relationship with clinicopathological parameters was also analyzed.Results CXCL12 and CXCR7 were detected in both breast carcinomas tissues and normal tissues,but the expression level of CXCL12 and CXCR7 were found up-regulated in breast carcinomas tissues(73.02%,65.87%) as compared with normal tissues(20.63%,22.22%,P 0.05).The CXCL12 and CXCR7 expression rate was significantly higher in the positive lymph node metastasis group(80.59%,76.12%) as compared to that in the negative lymph node metastasis group(64.40%,54.23%)(P 0.05).RT-PCR also confirmed the presence of positive CXCL12 and CXCR7 expression in the lymph node metastasis group.The positive expression of CXCR7 was correlated with bone metastasis.The expression level of CXCL12 and CXCR7 correlated well with lymph node metastasis(P 0.05).However,no relationship can be established between the CXCL12 and CXCR7 expression level and patients' age,tumor size,tumor differentiation(P 0.05).Conclusion The expression level of CXCL12 and CXCR7 is closely associated with lymph node metastasis of breast carcinomas.The expression level of CXCR7 is associated with bone metastasis.The selectively inhibiting CXCR7 overexpression may be an effective approach to control bone metastasis of breast carcinomas.