Abstract: Objective To investigate whether Notch1 gene leads to change of proliferation in human neuroblastoma SH-SY5Y cell line. Methods Notch1 gene activation of SH-SY5Y cells was blocked using γ-secretase inhibiter DAPT or knockdown with recombination lentivirus which express Notch1-shRNA. RT-PCR and Western Blot were applied to monitor the validity of down-regulation of notch1 and Hes1 expression. MTT assay was performed for examining cell proliferation in vitro. The influence of Notch1 RNAi on the implanted tumor growth was observed. Results DAPT and the lentiviral vectors expressing Notch1-shRNA were confirmed to be efficient in down-regulating notch1(NICD) and Hes1 expression. The down-regulation Notch1 gene inhibited cell proliferation significantly (P<0.01). The implanted tumor weight in Notch1-knockdown group was markedly lower than that in control group (0.20±0.13g vs. 0.89±0.58g, P<0.01). Conclusion Notch1 gene activation, which can lead to the change of proliferation in human neuroblastoma SH-SY5Y cell line, is likely to be potential molecular target for neuroblastoma in gene therapy.

Key words: Key Words:　 neuroblastoma, Notch1 gene, RNA interference, DAPT, cell proliferation