Gene expression inhibition of N-Myc downregulated gene 1 (NDRG1) monitoring and facilitation via transfectional transfer of NDRG1-siRNA constructs into- in vitro-cultured human glioblastoma cells

siRNA is a potent tool for artificially modulating gene expression through the introduction of short interfering RNAs. NDRG1 is a member of the N-myc downregulated gene (NDRG) family and is induced via different physiological and pathological conditions (hypoxia, cellulardifferentiation, heavy metal, Nmyc, neoplasia) modulatin NDRG1 transcription, mRNA stability and translation. Hypoxia, among other diverse factors, induces NDRG1 expression and plays an important role in its regulation of expression. siRNA- and iodoacetate (IAA)-mediated downregulation of NDRG1 mRNA and protein expression in vitro in human glioblastoma cell lines showed a nearly complete inhibition of NDRG1 expression when compared to the results obtained due to the inhibitory role of glycolysis inhibitor IAA. Hypoxia responsive elements (HREs) bound by nuclear HIF-1· in human glioblastoma cells in vitro under different oxygenation conditions and the clearly enhanced binding of nuclear extracts from glioblastoma cell samples exposed to extreme hypoxic conditions confirmed the HIF-1 Western blotting results. Due to its clear regulatory behavior under hypoxic condition in human tumor cells, NDRG1 represents an additional diagnostic marker for brain tumor detection, due to the role of hypoxia in regulating this gene, and it can represent a potential target for tumor treatment in human glioblastoma. siRNA method can represent an elegant alternative to modulate the expression of the hypoxia induced NDRG1 gene and can help to monitor the development of the cancer disease treatment outcome through monitoring the experession of this gene in the patients undergoing the different therapeutic treatment alternatives available nowadays.