gms | German Medical Science

Objective: Glioblastoma multiforme (GBM) is characterized by a strong and diffuse infiltration of the surrounding brain tissue. By that, some GBM cells might escape anti-tumor treatment and cause secondary tumors even in distant brain areas. Adjuvants targeting tumor cell migration might support multimodal therapy. The diazeniumdiolate JS-K releases nitric oxide (NO) in gluthatione-S-transferase overexpressing GBM cells. JS-K is known to exert anti-invasive effects in breast cancer cells. The aim of this study was to investigate the effect of low dose JS-K on the migration activity of GBM cells and to explore the possible molecular pathways in vitro.

Method: GBM cell lines U87 and T98G as well as primary human GBM cells (IC) were used as cell culture model. Cells were treated with 0-3 µM JS-K over 4 h. Afterwards, the migration capacity was examined by cell motility assays, cytotoxic and anti-proliferative effects of JS-K on GBM cells were analyzed by MTT and BrdU incorporation assays (0-96 h), respectively. Changes in the expression of matrix metalloproteinases (MMP) 2, 7, and 9 and of tissue inhibitor metalloproteinases (TIMP) 1 - 4 induced by JS-K were assessed by Polymerase Chain Reaction (PCR) and Western blot analysis. JS-K dependent effects on MMP 2/7/9 activity were analyzed by zymography and S-nitrosylation status determination by Western blot. Statistical analysis was performed by student’s t-test.

Results: Neither cell viability nor proliferation activity of GBM cells was influenced by JS-K in low concentrations. In contrast, a significant reduction in migration activity by concentrations ≥2 µM JS-K was detectable, most prominently after 96 h. However, expression of MMP 2, 7, and 9 and TIMP 1 - 4 was not affected by JS-K as shown by PCR and Western blot. Zymography demonstrated only a reduced MMP-2 activity by NO after 48 h. This inhibition was independent of protein-S-nitrosylation by JS-K.

Conclusions: JS-K reduces GBM cell migration significantly at low doses predominantly via the inhibition of MMP 2. This makes JS-K a promising candidate as adjuvant in the multimodal GBM therapy reducing invasion of tumor surrounding tissue and, by that, might reduce the risk of tumor recurrence.