For better understanding cancer pathogenesis and searching a potential target for antineoplastic therapy, the authors have studied mRNA expression profile in tissues from 39 children with histological confirmed malignant sarcomas and from 23 patients with bone and soft tissue nonmalignant lesions. mRNA levels of Angiogenesis-related genes VEGFA (including isoforms of 121, 165, 189), VEGFC, VEGFR-1, VEGFR-2, VEGFR-3, HIF-1α, TF, TFPI-1, TFPI-2, uPA, PAI-1 in pediatric specimens were examined using quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). uPA, HIF-1α, VEGFR-1, VEGFR-2, VEGFR-3, and VEGFC mRNA levels from nonmalignant tissue were significantly higher than those from cancer tissue.
Furthermore, ectopic PLOD2 expression restores migration and metastatic potential in HIF-1α-deficient tumors, and analysis of human sarcomas reveals elevated HIF1A and PLOD2 expression in metastatic primary lesions.
HT1080 sarcoma xenografts had increased hypoxia and/or HIF-1α activity with increasing tumor size and with anti-VEGF receptor antibody (DC101) treatment.
Moreover, cell lines derived from primary sarcomas lacking HIF-1α, or in which HIF-1α was knocked down, had decreased clonogenic survival in vitro, demonstrating that HIF-1α can promote radiation resistance in a cell autonomous manner.
These observations suggest that regulation and expression of both PHD2 and HIF-1a are important to the biology of sarcomas, and that loss of PHD2 function has an additional adverse effect in the prognosis of sarcomas in tumors expressing HIF-1a.
This leads to HIF1α-mediated sarcoma cell invasion and enhanced metastatic capacity in vivo, highlighting a translationally regulated YB-1-HIF1α axis in sarcoma metastasis.