KSHV-induced ligand mediated activation of PDGF receptor-alpha drives Kaposi's sarcomagenesis
Fig 7
Maintenance of tumorigenesis in KSHV-negative mECK36 tumors through PDGFRA activating mutations.
(A) Phosphorylated PDGFRA, total PDGFRA, PDGFA and PDGFB levels from KSHV+ve mECK36 and KSHV-ve mECK36 tumors determined by immunoblotting. (B) mRNA levels of PDGFs and PDGFRs in KSHV+ve mECK36 and KSHV-ve mECK36 tumors determined by RT-qPCR. Data are from three tumors carried out in triplicate and are presented as means ± SD. *P < 0.05. (C) ELISA of Platelet-Derived Growth Factor AA (PDGF-AA) and Platelet-derived growth factor subunit BB (PDGF-BB) in KSHV+ve mECK36 and KSHV-ve mECK36 tumor tissues. Data are from three tumors and are presented as means ± SD. *P < 0.05. (D) Immunohistochemistry staining of KSHV+ve mECK36 and KSHV-ve mECK36 tumor tissues using antibodies against PDGFA, PDGFB, LANA, and phospho-PDGFRA. (E) Mouse Growth Factor Antibody Array used to detect 30 Mouse Growth Factors in KSHV+ve and KSHV-ve tumors. Data is presented as fold change expression between KSHV+ve mECK36 and KSHV-ve mECK36 tumor tissue. (F) Sequence alignment of the hot spot region for oncogenic mutations in the activation domain of TKs. The D842V mutation in PDGFRA was only found in the cDNA of tumorigenic KSHV-negative mECK36 cells. (G) Tumor growth curve from mice with established subcutaneous KSHV-negative mECK36 tumors treated with Imatinib (150 mg/Kg twice daily) or Sunitinib (80 mg/Kg/day) by oral administration. Data indicate mean tumor size ± SD (n = 10).