Jornal de Toxicologia Clínica
Acesso livre

Abstrato

Effect of 2-Methoxyestradiol on Dephosphorylation of Neuronal Nitric Oxide Synthase in Osteosarcoma 143B Cells. An in vitro study

Gorska M, Kuban-Jankowska A, Antoniewicz J and Wozniak M

Objective: 2-methoxyestradiol, an endogenous metabolite of anticancer agent, has been evaluated in ongoing advanced phases of clinical trials as an anticancer agent. The aim of the study was to determine the impact of 2- methoxyestradiol on phosphorylation status of neuronal nitric oxide synthase at position of serine 847. We determined also influence of the compound on the gene and protein expressions, phosphorylation status of PP2A phosphatase.

Methods: In the current study we used western blotting, real time PCR, and ELISA assays.

Results: We demonstrated that 2-methoxyestradiol decreases the level of neuronal nitric oxide synthase phosphorylated at position of serine 847 referred to as inactive pool of enzyme. The expression of PP2CA gene was down-regulated by 2-methoxyestradiol at concentration of 1 μM. 10 μM did not statistically significant impact on phosphatase gene expression. Moreover, 1 μM 2-methoxyestradiol up-regulated protein level of PP2A while 10 μM did not exert any effect.

Conclusions: 2-methoxyestradiol decreased an inactive pool of neuronal nitric oxide synthase. Additionally, in a concentration-dependent manner it impacts on the gene and protein expressions, as well as phosphorylation status of PP2A-α phosphatase. Increasing activity of neuronal nitric oxide synthase by reversible phosphorylation may constitute an important tool resulting in osteosarcoma cell death.