IGFBP-3 is regulated by Gli signaling in cartilage tumors.

Mice that develop benign cartilage lesions due to overexpression of Gli2 in chondrocytes developed lesions similar to chondrosarcomas when also deficient in p53. Gli2 overexpression and p53 deficiency had opposing effects on chondrocyte differentiation, but had additive effects negatively regulating apoptosis. Regulation of Igfbp3 expression and IGF signaling by Gli and p53 integrated their effect on apoptosis. Treatment of human chondrosarcomas or fetal mouse limbs explants with IGFBP3 or by blocking IGF increased the apoptosis rate, and mice expressing Gli2 developed substantially fewer tumors when also deficient for Igf2. IGF signaling meditated apoptosis regulates the progression to malignant chondrosarcoma.

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Ho L, Stojanovski A, Whetstone H, Wei QX, Mau E, Wunder JS, Alman B