Matrix Metalloproteinase-9/Neutrophil Gelatinase-Associated Lipocalin Complex Activity in Human Glioma Samples Predicts Tumor Presence and Clinical Prognosis

Abstract

Matrix metalloproteinase-9/neutrophil gelatinase-associated lipocalin (MMP-9/NGAL) complex activity is elevated in brain tumors and may serve as a molecular marker for brain tumors. However, the relationship between MMP-9/NGAL activity in brain tumors and patient prognosis and treatment response remains unclear. Here, we compared the clinical characteristics of glioma patients with the MMP-9/NGAL activity measured in their respective tumor and urine samples. Using gelatin zymography assays, we found that MMP-9/NGAL activity was significantly increased in tumor tissues (TT) and preoperative urine samples (Preop-1d urine). Activity was reduced by seven days after surgery (Postop-1w urine) and elevated again in cases of tumor recurrence. The MMP-9/NGAL status correlated well with MRI-based tumor assessments. These findings suggest that MMP-9/NGAL activity could be a novel marker to detect gliomas and predict the clinical outcome of patients.

Figure 1

Enzymic activity of MMPs in tumor and urine samples of glioma patients. (a) Gelatin zymography analysis of specimens from a representative control subject and a patient with glioma. Arrows indicate the four active MMPs detected in TT samples (MMP-2, MMP-9, MMP-9/NGAL, and MMP-9D), whereas only weaker MMP-2 and MMP-9 are present in AT from the same patient. Urine from the control had no detectable MMP activity band but had visible MMP activity in Preop-1d urine. MMP-9, MMP-9/NGAL, and MMP-9D activities in Postop-1d urine were significantly increased and quickly decreased in Postop-1w urine, compared with that in Preop-1d urine. (b) Quantification of control and glioma patients with MMP-2, MMP-9, MMP-9/NGAL, and MMP-9D activities detected in Preop-1d urine. Among the 35 tumor patients, MMP-9/NGAL activity was detected in most gliomas (positive for 85.7%); it was not detected in control subjects (AT: adjacent nontumor tissue, TT: tumor tissue, and Preop-1d, Postop-1d, and Postop-1w urine: fresh urine samples were collected in the morning one day prior to surgery, the day after surgery, and one week after surgery).

Figure 2

MMP-9, MMP-9/NGAL, and MMP-9D activity is reduced after tumor removal and recovered after tumor relapse. (a) Gelatin zymography analysis of urine samples from a representative subject who has experienced tumor relapse six months after surgery. (b–d) MRI analysis of the tumor (arrow) from the corresponding patient prior to surgery (b), after surgery (c), and at diagnosis of relapse (d) (AT: adjacent nontumor tissue, TT: tumor tissue, and Preop-1d, Postop-1w, and Post-r urine: fresh urine samples were collected in the morning one day prior to surgery, one week after surgery, and on the day of tumor recurrence diagnosis).