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. Author manuscript; available in PMC: 2022 May 1.
Published in final edited form as: Mol Cell Endocrinol. 2021 Feb 17;527:111213. doi: 10.1016/j.mce.2021.111213

Figure 4: The IRS proteins determine IR/IGF-1R signaling outcomes.

Figure 4:

The IRS proteins are essential signaling intermediates of the IR and IGF-1R and they influence the functional response to pathway stimulation. Both IRS-1 and IRS-2 promote tumor cell survival by activating anti-apoptotic pathways in response to IR/IGF-1R stimulation. However, IRS-1 and IRS-2 also regulate distinct functions and their relative expression determines these outcomes. Breast carcinoma cells that express predominantly IRS-1 proliferate in response to IR/IGF-1R stimulation. IRS-1 localizes to the nucleus where it promotes the transcription of cell cycle regulatory genes. Breast carcinoma cells that express predominantly IRS-2 migrate and invade in response to IR/IGF-1R stimulation. IRS-2 signaling also regulates glucose uptake through GLUT-1, which enhances invasion.