| Abstract: |
Insulin-like growth factor (IGF) I has important growth regulatory functions in normal growth and development. IGF-I is also a mitogen for a number of cancer cell lines; however, its autocrine effect has not been well established. In this study, the expression of IGF-I, its receptor, and its major serum-binding protein were examined in 5 normal human mesothelial (NHM) cell samples and 11 pleural mesothelioma cell lines. All NHM cells and mesothelioma cell lines expressed IGF-I, IGF-binding protein 3 (IGFBP-3), and IGF-I receptor mRNA by either Northern blot or reverse transcription polymerase chain reaction analysis. IGF-I (0.136 0.024 ng/ml, mean SEM) and IGFBP-3 (18.5 3.2 ng/ml) proteins were readily detected in the conditioned medium of mesothelioma cell lines but were not greater than corresponding measurements in that of NHM cells (IGF-I, 0.120 0.080 ng/ml; IGFBP-3, 15.9 1.3 ng/ml). Exogenous recombinant IGF-I stimulated cell proliferation of NHM cells, demonstrating the presence of a functional IGF-I receptor. Our results suggest that IGF-I may function as an autocrine growth stimulus in normal proliferating mesothelial cells, which may contribute to their malignant transformation. © 1993, American Association for Cancer Research. All rights reserved. |
| Keywords: |
controlled study; human cell; polymerase chain reaction; cell proliferation; cell division; gene expression; culture medium; mitogenesis; cancer cell culture; tumor cells, cultured; somatomedin c receptor; receptor, igf type 1; messenger rna; rna, messenger; cell transformation; carrier proteins; growth regulation; mesothelioma; epithelial cells; somatomedin c; epithelium; insulin-like growth factor i; pleural neoplasms; somatomedin binding protein; mesothelium cell; northern blotting; human; priority journal; article; support, u.s. gov't, p.h.s.; insulin-like growth-factor-binding proteins; recombinant somatomedin c
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