Effects of RNA interference on expression of neutrophil gelatinase-associated lipocalin gene in human glioma cells

Objective To investigate the effect and mechanism of RNA interference on the expression of neutrophil gelatinase associated lipocalin (NGAL) gene in human glioma cells. Methods The proteins in human glioma tissues and glioma SHG-44, U87 and U251 cells were extracted, the expression of NGAL protein was detected; siRNA-NC, NGAL-siRNA1, NGAL-siRNA2, NGAL-siRNA3 transfected U251 cells, and not transfected with any siRNA as the control group, each group of cells transfected for 48 h, expression of NGAL protein were detected by Western blotting; cell apoptosis was detected cells transfected for 48 h by flow cytometry, the expression of Cleaved Caspase-3, Notch1, hairy and enhancer of split 1 (Hes1) protein was detected by Western blotting. Results The expression of NGAL mRNA and protein in gliomas was significantly higher than that in the tumor adjacent tissues (tmRNA=7.113, PmRNA=0.003; tprotein expression=8.532, Pprotein expression=0.002), NGAL protein expression in U251 cell was the highest, and was selected as a follow-up study, the apoptosis rate (15.62±1.94)% and expression of Cleaved Caspase-3 (0.094±0.021) protein in NGAL-siRNA was significantly higher than the control group (2.18±0.67), (0.032±0.015), the expression of Notch1 (0.204±0.028) and Hes1 (0.103±0.019) protein was significantly lower than the control group (0.453±0.041, 0.215±0.029), (tapoptosis rate=9.995, Papoptosis rate=0.001; tCleaved Caspase-3=5.898, PCleaved Caspase-3=0.006; tNotch1=8.112, PNotch1=0.003; tHes1=8.824, PHes1=0.003). Conclusion NGAL gene was highly expressed in human glioma tissues and cells, to inhibit the expression of NGAL by RNA interference could inhibit the proliferation and promote apoptosis of human glioma cells, its mechanism was related to notch the signal pathway. Key words: RNA interference; Neutrophil gelatinase associated lipocalin; Glioma; Apoptosis