The ADMR receptor mediates the effects of adrenomedullin on pancreatic cancer cells and on cells of the tumor microenvironment.

Imagen de Pablo Vivas-Mejia
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TítuloThe ADMR receptor mediates the effects of adrenomedullin on pancreatic cancer cells and on cells of the tumor microenvironment.
Publication TypeJournal Article
Year of Publication2009
AutoresRamachandran, V, Arumugam, T, Langley, R, Hwang, RF, Vivas-Mejia, P, Sood, AK, Lopez-Berestein, G, Logsdon, CD
JournalPLoS One
Volume4
Issue10
Paginatione7502
Date Published2009
ISSN1932-6203
Palabras claveAdrenomedullin, Animals, Cell Line, Tumor, Endothelial Cells, Endothelium, Vascular, Gene Expression Regulation, Neoplastic, Humans, Ligands, Lung, Mice, Neoplasm Metastasis, Neovascularization, Pathologic, Pancreatic Neoplasms, Receptors, Adrenomedullin, Receptors, Peptide, Stromal Cells
Abstract

BACKGROUND: Adrenomedullin (AM) is highly expressed in pancreatic cancer and stimulates pancreatic cancer cells leading to increased tumor growth and metastasis. The current study examines the role of specific AM receptors on tumor and cells resembling the tumor microenvironment (human pancreatic stellate--HPSC, human umbilical vein-- HUVEC and mouse lung endothelial cells--MLEC).

METHODS AND FINDINGS: AM receptors ADMR and CRLR were present in HPSC, HUVEC and MLECs while PDAC cells possessed only ADMR receptors as assessed by RT-PCR and western blotting. All cell lines expressed and secreted AM as indicated by ELISA. The growth of each of the cell lines was stimulated by exogenous AM and inhibited by the antagonist AMA. AM also stimulated in vitro angiogenesis assessed by polygon formation of endothelial cell lines. SiRNA-mediated silencing of ADMR, but not CRLR, reduced basal growth of all cells examined and reduced polygon formation of endothelial cells in vitro. Orthotopic tumors developed with shADMR bearing cancer cells had dramatically reduced primary tumor volume (>90%) and lung and liver metastasis compared to shControl bearing cells. To validate ADMR as a potential therapeutic target, in vivo studies were conducted using neutral nanoliposomes to systemically deliver human siRNA to ADMR to silence human cancer cells and mouse siRNA to ADMR to silence mouse tumor stromal cells. Systemic silencing of both human and mouse ADMR had no obvious adverse effects but strongly reduced tumor development.

CONCLUSION: ADMR mediates the stimulatory effects of AM on cancer cells and on endothelial and stellate cells within the tumor microenvironment. These data support the further development of ADMR as a useful target treatment of pancreatic cancer.

DOI10.1371/journal.pone.0007502
Alternate JournalPLoS ONE
PubMed ID19847298
PubMed Central IDPMC2760778
Grant ListCA16672 / CA / NCI NIH HHS / United States
DK052067 / DK / NIDDK NIH HHS / United States
P20 CA101936 / CA / NCI NIH HHS / United States