Evidence for further heterogeneity of the receptors for neuropeptide-Y and peptide-YY in tumor cell lines derived from neural crest.
The expression and structure of the receptors for neuropeptide-Y (NPY) and peptide-YY (PYY) were studied in 16 human and rodent tumor cell lines derived from the neural crest by ligand binding and cross-linking techniques using [125I]Bolton-Hunter-NPY, [125I]PYY, and various forms of monoiodinated NPY and PYY. Although NPY-binding sites were observed in most of the tumor cells, PYY-binding sites were found only on the human neuroblastoma cell lines SMS-MSN, SMS-KAN, SK-N-MC, and MC-IXC and the human Ewing's sarcoma cell line SK-ES. The differential labeling of the NPY/PYY receptors on these cell lines suggests that the NPY/PYY receptors are more heterogeneous than previously described as the Y1, Y2, and Y3 receptor subtypes. Cross-linking studies demonstrate that the Y1 and Y2 receptors for NPY/PYY are structurally different (mol wt, 70 and 50 kilodaltons, respectively) and that the 70- and 50-kilodalton receptor proteins are coexpressed in certain tumor cell lines. This could explain at least in part why cell lines show a relative specificity for Y1/Y2 classification, observed as the inhibition by both C-terminal fragments and Y1-specific analogs on the NPY/PYY binding to membrane receptors. Collectively, the present study suggests further heterogeneity of the NPY/PYY receptors and the existence of multiple receptor proteins in the tumor cell lines derived from the neural crest.
Inui
A
A
Second Department of Internal Medicine, Kobe University School of Medicine, Japan.
Sano
K
K
Miura
M
M
Hirosue
Y
Y
Nakajima
M
M
Okita
M
M
Baba
S
S
Kasuga
M
M
D000818:Animals; D005910:Glioma / Q000737:chemistry / Q000473:pathology / Q000648:ultrastructure; D006801:Humans; D007457:Iodine Radioisotopes; D008024:Ligands; D009432:Neural Crest / Q000737:chemistry* / Q000473:pathology / Q000648:ultrastructure; D009447:Neuroblastoma / Q000737:chemistry / Q000473:pathology / Q000648:ultrastructure; D016716:PC12 Cells; D019894:Peptide YY; D010455:Peptides / Q000378:metabolism*; D051381:Rats; D017476:Receptors, Neuropeptide Y / Q000032:analysis*; D017981:Receptors, Neurotransmitter / Q000032:analysis*; D014407:Tumor Cells, Cultured
D007457:Iodine Radioisotopes; D008024:Ligands; D010455:Peptides; D017476:Receptors, Neuropeptide Y; D017981:Receptors, Neurotransmitter; D019894:Peptide YY