Moreover, a recent study has shown that AMD3100, a small synthetic inhibitor of CXCR4, not binds only to CXCR4, but also to CXCR7 [31]. We propose that more attention should be paid to CXCL12/CXCR4 axis and CXCL12/CXCR7 axis.

Thus, further studies elucidating the role of CXCL12/CXCR7 axis in cancer development is needed. Conclusions In summary, CXCR7 was highly expressed in hepatocellular carcinoma tissues. We presented the first evidence that suppression of CXCR7 expression by RNA interference impairs in vitro cellular invasion, adhesion, VEGF secretion and angiogenesis. We also observed that knockdown of CXCR7 significantly inhibited tumor GW-572016 cell line growth but

not metastasis in vivo. Moreover, we found that VEGF stimulation Selleck HKI 272 up-regulated the expression of CXCR7 in SMMC-7721 cells and HUVECs. Taken together, this study provides novel evidence that inhibition of CXCR7 expression may be an effective PCI-34051 order approach to suppressing tumor growth of HCC. Acknowledgements We are extremely grateful to professor Weixue Tang (Chongqing Key Laboratory of Neurology, Chongqing, China) for her technical support, and Tingxiu Xiang (Chongqing Key Laboratory of Neurology, Chongqing, China)for her helpful discussion. We also thank other staffs working in the Department of Endorine Surgery and Breast Cancer Centre, the First Affiliated Hospital of Chongqing Medical University for they supported our work. References 1. Mann CD, Neal CP, Garcea G, Manson MM, Dennison AR, Berry DP: Prognostic molecular markers in hepatocellular carcinoma: a systematic review. Eur J Cancer 2007,43(6):979–92.PubMedCrossRef 2. Tung-Ping Poon R, Fan ST, Wong J: Risk factors, prevention, and management of postoperative recurrence after resection of hepatocellular

carcinoma. Ann Surg 2000,232(1):10–24.PubMedCrossRef 3. Müller A, Homey B, Soto Montelukast Sodium H, Ge N, Catron D, Buchanan ME, McClanahan T, Murphy E, Yuan W, Wagner SN, Barrera JL, Mohar A, Verástegui E, Zlotnik A: Involvement of chemokine receptors in breast cancer metastasis. Nature 2001,410(6824):50–6.PubMedCrossRef 4. Miao Z, Luker KE, Summers BC, Berahovich R, Bhojani MS, Rehemtulla A, Kleer CG, Essner JJ, Nasevicius A, Luker GD, Howard MC, Schall TJ: CXCR7 (RDC1) promotes breast and lung tumor growth in vivo and is expressed on tumor-associated vasculature. Proc Natl Acad Sci USA 2007,104(40):15735–40.PubMedCrossRef 5. Pablos JL, Amara A, Bouloc A, Santiago B, Caruz A, Galindo M, Delaunay T, Virelizier JL, Arenzana-Seisdedos F: Stromal-Cell Derived Factor Is Expressed by Dendritic Cells and Endothelium in Human Skin. Am J Pathol 1999,155(5):1577–86.PubMedCrossRef 6.