Correlative analyses of IGF-1, p53, and Ki-67 (MIB-1) immunohistochemistry and IGF-1 receptor (IGF-1R) mRNA expression were performed to examine the cellular pattern of IGF-1 signaling in 39 cases of astrocytoma (World Health Organization grades II-IV).
Other less clearly defined abnormalities in astrocytomas include mutations of the retinoblastoma (RB) gene and overexpression of platelet-derived growth factor; transforming growth factor-alpha and -beta; the c-erb B-1, c-myc, ras, c-fos, and ros oncogenes; and insulin-like growth factor I and II.
The strong inappropriate expression of IGF-11 mRNA and its protein product in the tumor cells of astrocytomas and meningiomas, but not in normal brain specimens, may serve as molecular markers for the early detection of these tumors.