Functional expression of neuropeptide Y receptors in human neuroblastoma cells

Expression of neuropeptide Y (NPY) receptors in human SK-N-MC neuroblastoma cells was investigated. Reverse transcriptase-polymerase chain reaction (RT-PCR) revealed that Y1, Y4, and Y5 receptors were expressed in these cells. Expression was confirmed by Western blot and immunocytochemistry demonstrated abundant presence of all three receptors on cell membranes. NPY peptide was also expressed in these cells, but other members of the larger peptide family (peptide YY and pancreatic polypeptide) were not expressed. Incubation with U0126, a specific mitogen-activated protein kinase (MAPK) inhibitor, decreased cell number in serum-free medium culture. Since NPY activates MAPK via different subtypes of NPY receptors, results suggest that endogenously expressed NPY may control proliferation of these cells through a paracrine/autocrine mechanism.