preproenkephalin a ( ppa ) mrna expression was studied by northern blot and in situ hybridization in cell lines ( rat glioma c6 , rat hepatoma htc , human neuroblastoma imr32 , mouse neuroblastoma ns20y , rat fibroblast fr3t3 , human bladder carcinoma ej , human vulva carcinoma a431 , myelocytic leukemia hl60 , rat adrenal carcinoma y1 ) and in brain tumours ( implanted c6 cells ) .
C0016030
fibroblast
C0007634
cells