title: Thrombopoietin receptor levels in tumor cell lines and primary tumors.
abstract: Thrombopoietin (TPO) receptor agonists represent a new approach for the treatment of thrombocytopenia, which may develop as a consequence of immune thrombocytopenia, chemotherapy treatment, chronic hepatitis C infection, or myelodysplastic syndromes. There are concerns that use of certain growth factors can hasten disease progression in some types of hematologic malignancies and solid tumors. In this study, expression of MPL (TPO-R) mRNA was examined in tumor cell lines, patient tumor samples (renal cell carcinoma, prostatic carcinoma, soft tissue and bony/cartilage sarcoma, colon cancer, and lymphoma), and normal tissues using microarray analysis and qRT-PCR. MPL mRNA is expressed at very low or undetectable levels compared with erythropoietin receptor (EPOR), human epidermal growth factor (ERBB2; HER2), and insulin-like growth factor-1 receptor (IGF1R) in these patient samples. These data suggest TPO-R agonists will likely preferentially stimulate proliferation and differentiation of cells of megakaryocytic lineage, potentially demonstrating their utility for correcting thrombocytopenia in clinical settings.
authors.affiliation: Oncology Biology, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, PA 19426-2990, USA.
authors.forename: Connie L
authors.initials: CL
authors.lastname: Erickson-Miller
authors.forename: Antony
authors.initials: A
authors.lastname: Chadderton
authors.forename: Anna
authors.initials: A
authors.lastname: Gibbard
authors.forename: Jennifer
authors.initials: J
authors.lastname: Kirchner
authors.forename: Kodandaram
authors.initials: K
authors.lastname: Pillarisetti
authors.forename: Katherine
authors.initials: K
authors.lastname: Baker
authors.forename: Lini
authors.initials: L
authors.lastname: Pandite
authors.forename: Iman
authors.initials: I
authors.lastname: El-Hariry
authors.forename: Yasser
authors.initials: Y
authors.lastname: Mostafa Kamel
authors.forename: Yuan
authors.initials: Y
authors.lastname: Liu
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Martin
authors.forename: Conrad
authors.initials: C
authors.lastname: Messam