Figure 7.

SP1/miR‐326 modulated the proliferation and metastasis of 143B cells in nude mice. A, Transfection with SP1‐siRNA vector decreased SP1 but increased miR‐326 expression in 143B‐cell‐xenografted tumour, as indicated by the results form PCR assay. Treatment with miR‐326 inhibitor (antagonist) abolished the increased of miR‐326 expression caused by SP1 knockdown. B, SP1 knockdown inhibited 143B tumour growth in nude mice. However, the inhibition of tumour growth was abolished by the reduction of miR‐326. C, As indicated by immunohistochemistry, SMO and Ki67 protein abundances were decreased with SP1 knockdown. D, In lung tissues, SP1 knockdown was associated to smaller size of 143B tumour, but knockdown of both SP1 and miR‐326 dramatically boosted the growth of 143B tumour. E, The molecular mechanism by which SP1/miR‐326 regulated the proliferation and metastasis of OS. Sp1 epigenetically down‐regulated miR‐326 by recruiting HDAC1. Down‐regulated miR‐326 caused the overactivation of Hedgehog signalling pathway, resulting in the rapid proliferation, suppressed apoptosis and enhanced metastasis of OS. **P < .01, ***P < .001 vs control group