Experimental Study Of The Inhibition Of Cell Proliferation And Metastases By Doxycycline In Human Colon Carcinoma

Objective: To investigate the mechanism of inhibition of cell proliferation, expre -ssion of MMP-2,9 in vitro in human colon cancerMethods: The inhibition of cell proliferation by doxycycline(DC) was determined by MTT. The cell apoptosis was detected by flow cytometry dyed by AnnexinV-PI and the cell mitochondrial membrane potential was also detected by flow cytometry. The expression of MMP-2 and MMP-9 was detected by immunohistochemical method.Results: (1)Significant differences were found by MTT after compared the control group with the cells treated with DC, which showed that the percentage of growth inhibiting cells treated with 5μg/ml,10μg/ml,20μg/mlDC for 24h were 16.4%,37.0%,44.6%(P<0.01;P<0.01;P<0.01) and for 48h were 18.6%,36.7%,49.2%(P<0.01;P<0.01;P<0.01).(2)Significant differentces were found by flow cytometry after compared the control group with the cells treated with DC, which showed that the percentage of apoptosiss cells treated with 5μg/ml,10μg/ml,20μg/mlDC for 24h were 7.79±0.07%,16.05±0.25%,17.42±0.08% ( P<0.01;P<0.01;P<0.01), while the control group was 1.04±0.05%. (3) Significant differentces were also found by flow cytometry after compared the control group with the cells treated with DC, which showed that the percentage of the descent of the cell mitochondrial membrane potential treated with 5μg/ml,10μg/ml,20μg/mlDC for 24h were 6.53±0.06%,23.28±0.47%,26.08±0.39% (P<0.01;P<0.01;P<0.01), while the control group was 1.51±0.03%. (4)The immunohistochemical method show that the expressions of MMP-2 and MMP-9 were decreased on dose dependent after cells treated with DC.