Objective   To construct an expressing vector encoding short hairpin RNA (shRNA) targeting chemokine receptor 7 (CXCR7) and explore its effect on the proliferation

apoptosis

and cycle of the human breast cancer cell line MDA-MB-435s.    Methods   Expressing vector of CXCR7 shRNA was constructed and transfected into MDA-MB-435s cells. Expression levels of CXCR7 mRNA and CXCR7 protein were assayed by RT-PCR and Western blot analysis respectively. Cell proliferation was measured by MTT method

cell apoptosis by TUNEL assay

and cell cycle by flow cytometry.    Results   Recombinant expressing vector CXCR7 shRNAs was successfully constructed. Enzyme digesting and sequencing showed that the insertion sequence was correct. After transfection of 2 CXCR7 shRNA vectors (CXCR7-shRNA1 and CXCR7-shRNA2)

the expression levels of CXCR7 protein and CXCR7mRNA in the MDA-MB-435s cells were significantly decreased compared with those of control shRNA and untreated cells (P0.05). The proliferation of cancer cells was decreased significantly (P0.05) while the apoptosis was increased significantly after CXCR7-shRNA1 and CXCR7-shRNA2 transfection (P0.05). However

the cell cycle had no significant difference compared with those of control shRNA and untreated cells.    Conclusion   Recombinant expressing vector CXCR7 shRNAs effectively inhibits the expression of CXCR7

and suppresses the proliferation of MDA-MB-435s cells to promote cell apoptosis

but has no obvious influence on the cell cycle after the inhibition of the CXCR7.