CD47-SIRPα Axis as a Biomarker and Therapeutic Target in Cancer: Current Perspectives and Future Challenges in Nonsmall Cell Lung Cancer

Figure 1

The CD47-SIRPα interaction plays a key role in phagocytosis inhibition. The CD47-SIRPα interaction leads to the phosphorylation of two tyrosine residues in the ITIM motif included in SIRPα’s cytosolic domain. Phosphorylation recruits and activates SHP1 & SHP2, signaling a cascade of events that leads to the dephosphorylation of myosin IIA and, therefore, inhibition of the cytoskeleton rearrangement, which is a necessary step for macrophages to engulf target cells. In tumor cells, the enhanced activity of the CD47-SIRPα axis is achieved by increasing CD47 expression.