RNA interference technology was employed to detect effect of CCR7 deficiency on the expression of MMP-9 in SW480 human colon cancer cells. We also evaluated the ability of CCR7 short hairpin RNA to inhibit MMP-9 production and tumour invasion in a xenografted mouse model by using whole-body fluorescence imaging and gelatin zymography.
We found that CCR7 short hairpin RNA significantly inhibited C–C ligand 21/CCR7-induced up-regulation of MMP-9 in SW480 cells. Furthermore, knockdown of CCR7 significantly limited the production of MMP-9 and colon cancer metastasis in a xenografted mouse model. Mice that received SW480/control cells had progressively enlarging tumours and more lymphatic metastases, and these animals did not survive as long as mice that received SW480/CCR7− cells.
MMP-9 and CCR7 may be useful targets for the treatment of lymphatic metastasis in colon cancer.