MMP9 and prostate cancer: It also has been shown that tetrandrine inhibits the migration and invasion of SiHa human cervical cancer cells via matrix metalloproteinase-2 (MMP-2) and MMP-9 down-regulation [24], and this natural substance suppresses the metastatic phenotype of prostate cancer cells by negatively regulating Akt/mTOR/MMP-9 signaling pathway [25].