Matrix metalloproteinase 2,9 expression and DNA damage during treatment with verapamil and /or doxorubicin in murine tumor cells

ABSTRACT

This study aims to examine the effects of verapamil and/or Doxorubicin [DOX] treatment on the Matrix metalloproteinase [MMPs] expression and DNA damage in murine tumor cells. Tummbearing mice treated with DOX [2mg/kg I. P. every other day X3] and/or verapamil [20 mg/kg I. P. daily for 5 days]. After last injection Ehrlich ascites carcinoma cells [EAC-cells] were withdrawn tot preparation of protein lysate and DNA. Gelatin zymographic analysis [GZA] and DNA agarose gel electrophoresis, used for this determination of MMPs expression and DNA damage, respectively. DOX treatment showed 34.1 days median survival time with 20% long-term survivors. However, administration of verapamil before DOX increased the long-term survivors to 60% with medium survival time of 44.4 days. Verapamil pretreatment increased the cellular level of DOX at all time points tested with maximum level appeared at 6 hours after treatment, 5.5 micro g/10[8] cells compared to 3.4 micro g/10[8] cells for DOX alone]. Using verapamil or DOX induced metalloproteinase activity and DNA damage, whereas their combination induced metalloproteinase isomer with low molecular weight at 24 hours which disappeared at 48 and 72 hours. Also combination of verapamil and DOX increased the amount of DNA degradation