MYCN and neuroblastoma: In the present study, three human NB cell lines, without MYCN amplification (ACN, GI-MEN, SH-SY-5Y) and a MYCN-amplified cell line (SK-N-BE-2C) were transiently transfected with an expression vector encoding PKCδ and incubated with 1 mM BSO for 24 h.