Modulation of u-PA, MMPs and their inhibitors by a novel nutrient mixture in human female cancer cell lines

Cancers of the breast, cervix, uterus and ovary are the most prevalent cancers in women worldwide. Proteases play a key role in tumor cell invasion and metastasis by digesting the basement membrane and ECM components. Strong clinical and experimental evidence demonstrates association of elevated levels of urokinase plasminogen activators (u-PA) and matrix metalloproteinases (MMPs) with cancer progression, metastasis and shortened patient survival. MMP activities are regulated by specific tissue inhibitors of metalloproteinases (TIMPs). Our main objective was to study the effect of a nutrient mixture (NM) on the activity of u-PA, MMPs and TIMPs in human breast, cervix, uterine and ovarian cancer cell lines. Human breast (MDA-MB-231 and MCF-7), cervical (HeLa), uterine (SK-UT-1) and ovarian (SKOV3) cancer cell lines were cultured in their respective media and treated at confluence with NM at 0, 50, 100, 250, 500 and 1000 mu g/ml. Analysis of u-PA activity was carried out by fibrin zymography, MMPs by gelatinase zymography and TIMPs by reverse zymography. Both breast and uterine cancer cell lines expressed u-PA, which was inhibited by NM in a dose-dependent manner. However, no bands corresponding to u-PA were detected for HeLa and SK-OV-3 cell lines. On gelatinase zymography, MDA-MB-231 and MCF-7 showed one band corresponding to MMP-9, HeLa showed two bands, an intense band corresponding to MMP-2 and a faint band corresponding to MMP-9, SK-UT-I showed PMA-induced MMP-9, and SK-OV-3 showed a band corresponding to MMP-2. NM inhibited their expression in all cell lines. The activity of TIMPs was upregulated in all cancer cell lines in a dose-dependent manner. Analysis revealed a positive correlation between u-PA and MMPs and a negative correlation between u-PA/MMPs and TIMPs. These findings suggest the therapeutic potential of NM in the treatment of female cancers.