Effects of hypoxia on mRNA expression of <i>IGF1R</i> and <i>IGF1</i>, and production of IGF1 in cancer cells.

<p>(A) <i>IGF1R</i> mRNA expression was significantly higher in RWP-1, MiaPaCa-2, and OCUP-AT cells than in Panc-1 cells. The mRNA expression level of IGF1R was increased under hypoxia in all four cancer cell lines. (B) Cell surface expression of IGF1R by FACScan analysis. IGF1R expression level of Panc-1, RWP-1, OCUP-AT, and MiaPaCa-2 cells was higher in hypoxia than that in normoxia. (C) Western blot analysis. Three independent experiments were performed. IGF1R bands was calculated by β-actin as internal standard to normalize expression levels IGF1R level under hypoxia was high in 3 of four pancreas cancer cell lines, Panc-1, OCUP-AT, and RWP-1, in comparison with that under normoxia, while Panc-1 did not significantly increase under hypoxia. (D) IGF1 mRNA expression was significantly increased under hypoxia in both pCaF-1 and pCaF-2 cells. (E) The concentration of IGF1 in conditioned medium from pCaF-1 and pCaF-2 cells was 380 and 253 pg/ml under hypoxia. IGF1 production in PDAC cells was not detected.