Gelatinase A (MMP-2) and
gelatinase B (MMP-9) are
proteolytic enzymes involved in process of
tumor invasion, and they are considered as possible
tumor markers in
breast cancer patients. In this study, we measured activity of latent and active form of MMP-2 and MMP-9 in
tumor and adjacent tissue of 60
breast cancer patients by SDS-PAGE zymography. The activity of both form of
gelatinases significantly increased with each advancing clinical stage of disease.
ProMMP-9 and aMMP-9 activity in
tumor tissue shows a positive association with
tumor size. Patients with lymph node involvement have higher
proMMP-2, aMMP-2 and aMMP-9 activity than node negative patients.
Steroid receptor-negative
tumors had enhanced aMMP-2 and aMMP-9 activity. Patients with basal-like
cancers had higher
proMMP-2 tumor activity and aMMP-2 adjacent tissue activity compared to patients with
luminal A
tumors. Patients with negative
hormone receptors are associated with increased activity of both form of
gelatinases in adjacent tissue. Reported increased activity of MMP-2 in
tumor and adjacent tissue of basal-like
tumors implicates that MMP-2 might have a role in aggressive biology of basal-like
cancers. Additional investigations regarding molecular pathways in adjacent tissue could give better insight into aggressive nature of basal-like
carcinomas.