title: Platelet-derived growth factor receptor-alpha: a novel therapeutic target in human hepatocellular cancer.
abstract: Hepatocellular cancer (HCC) is a disease of poor prognosis. Identifying novel molecular aberrations might present opportunities to identify new therapeutic targets. Due to the similarities between the processes of development and cancer, we used early developing livers to identify genes that might play a primary role in HCC. Platelet-derived growth factor receptor-alpha (PDGFRalpha) was identified from microarray using early developing mouse livers. Expression of PDGFRalpha and its upstream effectors, PDGF-AA and PDGF-CC, were examined in HCC tissues (n = 43) by Western blot, real-time PCR, and immunohistochemistry. Finally, effect of anti-PDGFRalpha antibody (mAb 3G3, ImClone Systems, Inc.) was examined on human hepatoma cells. A high expression of PDGFRalpha was observed during early liver development. HCCs (17 of 21) revealed cytoplasmic PDGFRalpha and activated PDGFRalpha (phospho-Tyr(754)) by immunohistochemistry. Additional HCCs (14 of 22) showed elevated PDGFRalpha levels when compared with the adjacent normal livers by Western blots. Of these 14 patients, 3 showed increased PDGFRalpha gene expression, 3 showed elevated PDGF-AA, and 4 had higher PDGF-CC levels in the tumors compared with adjacent livers. Multiple hepatoma cell lines, when treated with mAb 3G3, showed significant decreases in cell proliferation and survival (P < 0.05). In conclusion, approximately 70% of HCC tissues had elevated PDGFRalpha levels due to diverse mechanisms. PDGFRalpha inhibition in hepatoma cells led to diminution of tumor cell survival and proliferation and thus might be of therapeutic significance.
authors.affiliation: Department of Pathology, University of Pittsburgh School of Medicine, 200 Lothrop Street, S421-BST Pittsburgh, PA 15213, USA.
authors.forename: Peggy
authors.initials: P
authors.lastname: Stock
authors.forename: Dulabh
authors.initials: D
authors.lastname: Monga
authors.forename: Xinping
authors.initials: X
authors.lastname: Tan
authors.forename: Amanda
authors.initials: A
authors.lastname: Micsenyi
authors.forename: Nick
authors.initials: N
authors.lastname: Loizos
authors.forename: Satdarshan P S
authors.initials: SP
authors.lastname: Monga
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D006528:Carcinoma, Hepatocellular / Q000235:genetics / Q000378:metabolism* / Q000473:pathology / Q000628:therapy*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D008024:Ligands; D008099:Liver / Q000187:drug effects / Q000254:growth & development; D008113:Liver Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology / Q000628:therapy*; D051379:Mice; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D000911:Antibodies, Monoclonal; D008024:Ligands; D020796:Receptor, Platelet-Derived Growth Factor alpha