Profilin 1 Protein and Its Implications for Cancers

Profilin 1 (PFN1) is a ubiquitous small-molecule protein that exists in all eukaryotes. PFN1 was first identified as a G-actin sequestering molecule, and subsequently, its true functions in actin polymerization and F-actin dynamics were revealed. In the following decades, the structure of PFN1 was recognized to have 3 domains: an actin-binding domain, a poly-L-proline (PLP)-binding domain, and a phosphoinositide-binding domain. PFN1 plays a vital role in many cell functions, including membrane trafficking, endocytosis, cell cycle, motility, proliferation, cell survival, transcription, stemness, and autophagy (Figure 1). Abnormal expression or deletion of PFN1 can affect the normal physiological activity of cells and lead to disease development. PFN1 has been deeply studied in a variety of diseases, some genetic (eg, amyotrophic lateral sclerosis) and some chronic (eg, hypertension). In the past 10 years, PFN1's role in cancer has received increasing attention. In this review, we summarize the studies of PFN1 in cancer that have been completed in recent years, discuss the roles of PFN1 in cancer, and discuss the implications for tumor diagnosis and therapy in the future.