| Colorectal cancer is common and frequently-occurring tumor in our country, theincidence of the tumor is located at third position of malignant tumors, and its incidenceshows uptrend. Invasion and metastasis are more common at post-operation of colorectalcancer that affect seriously prognosis of the patients. About20%of patients with colorectalcancer progresses into the metastatic cancer, their survival rates for5years are less than10%.The changes of adhesive ability in tumor cells are the initiating step of tumor cellsoccurred invasion and metastasis. Matrix metalloproteinases (MMPs) hydrolyze the variousconstituents of ECM, and destroy the histological barrier that restricted the invasion of tumorcells. Gelatinases including MMP-2and MMP-9are the major proteolytic enzymeshydrolyzing type Ⅳ collagen in basement membrane. MMP-2and MMP-9are highlyexpressed in many kinds of tumor cells, and play an important role in the invasion andmetastasis of certain tumors. Juglone is an important substance isolated from juglandaccacplants. The experimental evidence has showed that juglone inhibits the proliferation ofhematological and solid tumor cells and induces apoptosis. However, only few data areavailable in the effects of juglone on invasion and metastasis of tumors.In the present study, MTT assay was used to select the optimal concentrations ofjuglone for adhesion assay. The adhesive ability of HCT-8cells was assessed injuglone-treated human colon cancer HCT-8cells. The activities of MMP-2and MMP-9inHCT-8cells were detected by gelatin zymography analysis, and the expression of MMP-2and MMP-9proteins was examined by Western blotting.The main results in the present study are as follows:（1）The certain concentrations of juglone inhibit the growth of human colon cancerHCT-8cells in a time-and concentration-dependent manner.（2）Compared with control group, the adhesion rates in HCT-8cells-treated withjuglone at concentrations of1.25,2.5,5,10and20μg/ml were significantly decreased in a concentration-dependent manner.（3）After HCT-8cells were treated with juglone at2.5,5,10and20μg/ml, theactivities of MMP-2was attenuated, and after the HCT-8cells were treated with juglone atthe tested concentrations, the activities of MMP-9were decreased.（4）The expression of MMP-2and MMP-9proteins was reduced in juglone-treatedHCT-8cells compared with control group.The main conclusions in this study are as follows:（1）Juglone significantly inhibited the adhesive ability of human colon cancer HCT-8cells in a concentration-dependent manner.（2）Juglone obviously reduced the activities of MMP-2and MMP-9, as well asdown-regulated the expression of MMP-2and MMP-9proteinsThe results suggest that juglone decreases the degradative ability of extracellular matrixin HCT-8cells in vitro, which may inhibit the invasion and metastasis of colorectal cancercells. The reduction in the activities of MMP-2and MMP-9and the down-regulation ofMMP-2and MMP-9proteins expression may be a mechanism by which juglone inhibits theadhesion of human colon cancer HCT-8cells. |
