Figure 6. A novel unidirectional cross talk from IGF-IR to Ob-R in breast cancer.
Our results indicate that the IGF-I and leptin receptors interact in human breast cancer cells. Further, cross talk occurs from IGF-IR to Ob-R such that IGF-I stimulation induces phosphorylation and activation of Ob-R. IGF-IR kinase inhibition blocks IGF-I-mediated Ob-R activation. Cross talk is unidirectional, as leptin does not activate IGF-IR.