Involvement of NOS2 activity on human glioma cell growth, clonogenic potential, and neurosphere generation

Aberrant nitric oxide synthase 2 (NOS2) expression has been suggested as an interesting therapeutic target that is being implicated as a component of the molecular profile of several human malignant tumors, including glioblastoma, which is the most aggressive brain tumor with limited therapeutic options and poor prognosis. The aim of the present work was to evaluate the effect of 1400W, a specific NOS2 inhibitor, on human glioma cells in terms of clonogenic potential, proliferation, migration rate, and neurosphere generation ability. NOS2 expression was determined by Western blotting. Nitric oxide (NO) production was measured through nitrite level determination. The trypan blue exclusion test and the plate colony formation assay were performed to evaluate cell proliferation and clonogenic potential. Cell proliferation and migration ability was assessed by the in vitro wound-healing assay. Neurosphere generation in a specific stemcell medium was investigated. NOS2 was confirmed to be expressed in both the glioma cell line and a human glioma primary culture, and overexpressed in relative derived neurospheres. Experiments that aimed to evaluate the influence of 1400W on U-87 MG, T98G (glioblastoma cell lines) and primary glioma cells sustained the crucial role played by NOS2 in proliferation, colony formation, migration, and neurosphere generation, thus supporting the emerging relevance of a NOS2/NO system as a prognostic factor for glioma malignancy and recurrence.