KiSS-1/G protein-coupled receptor 54 metastasis suppressor pathway increases myocyte-enriched calcineurin interacting protein 1 expression and chronically inhibits calcineurin activity.
OBJECTIVE
Tumor metastasis is a critical determinant of death from cancer. Metastin, a product of the KiSS-1 gene, is an endogenously expressed metastasis suppressor that is the ligand for G protein-coupled receptor 54 (GPR54), a Gq/11-coupled receptor. In the present study, our goal was to define the basis of GPR54 action using thyroid cancer cells as a model.


RESULTS
We used GPR54-null thyroid cancer cells to create a stable GPR54 overexpression model. Cell growth and cell migration of the GPR54-expressing lines were inhibited by recombinant metastin, and metastin stimulated the protein kinase C, ERK, and phosphatidylinositol-3-kinase pathways. To identify metastin-regulated genes, we performed microarray analyses using RNA isolated from GPR54 stable transfectants before and after 1 and 24 h of metastin stimulation. Consistent increases in expression of the gene encoding myocyte-enriched calcineurin interacting protein 1 (MCIP-1), an inhibitor of calcineurin, were identified and confirmed using real-time RT-PCR and Western blot. Functionally, metastin treatment of GPR54-expressing cells initially increased calcineurin activity, followed by a prolonged reduction in calcineurin activity for 24 and 48 h, consistent with the pattern of MCIP-1 expression. In addition, treatment with cyclosporin A, a calcineurin inhibitor, blocked cell migration. Lymph node metastasis in papillary thyroid cancers demonstrated loss of MCIP-1 expression in comparison with primary tumors.


CONCLUSIONS
These data suggest a role for MCIP-1 and calcineurin inhibition in GPR54-mediated metastasis suppression in human cancers.
The Ohio State University, 445D McCampbell Hall, 1581 Dodd Drive, Columbus, Ohio 43210, USA.
Nikolaos
N
Stathatos
Isabelle
I
Bourdeau
Allan V
AV
Espinosa
Motoyasu
M
Saji
Vasily V
VV
Vasko
Kenneth D
KD
Burman
Constantine A
CA
Stratakis
Matthew D
MD
Ringel
D065095:Calcineurin Inhibitors; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D004268:DNA-Binding Proteins; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D059648:Kisspeptins; D009124:Muscle Proteins / Q000378:metabolism*; D009362:Neoplasm Metastasis / Q000517:prevention & control; D020411:Oligonucleotide Array Sequence Analysis; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D043562:Receptors, G-Protein-Coupled; D000074502:Receptors, Kisspeptin-1; D018013:Receptors, Neuropeptide / Q000378:metabolism*; D013964:Thyroid Neoplasms / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology / Q000556:secondary; D013997:Time Factors; D025521:Tumor Suppressor Proteins; D015854:Up-Regulation
D065095:Calcineurin Inhibitors; D004268:DNA-Binding Proteins; D047908:Intracellular Signaling Peptides and Proteins; C106628:KISS1 protein, human; C118688:KISS1R protein, human; D059648:Kisspeptins; D009124:Muscle Proteins; D011506:Proteins; D011518:Proto-Oncogene Proteins; C108612:RCAN1 protein, human; D043562:Receptors, G-Protein-Coupled; D000074502:Receptors, Kisspeptin-1; D018013:Receptors, Neuropeptide; D025521:Tumor Suppressor Proteins; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D011493:Protein Kinase C; D048049:Extracellular Signal-Regulated MAP Kinases