Fig. 1. Down-regulation of endogenous NPY reduces neuroblastoma growth in vitro.
A. Expression of NPY was detected by real-time RT-PCR in eight tested neuroblastoma cell lines and its release confirmed by ELISA.
B. In SK-N-BE(2) cells, NPY siRNA inhibited expression of the peptide (real-time RT-PCR) and its release into the cell culture media (ELISA), which resulted in a decreased number of viable cells (MTS assay). The growth-inhibitory effect of NPY siRNA was rescued by exogenous NPY (10−7M).
(NC – negative control siRNA; NPY-1 and NPY-2 – two different siRNAs for NPY)
C. In three selected cell lines, NPY siRNA exerted growth-inhibitory effects comparable to this observed in SK-N-BE(2) cells.