Role of myosin heavy chain 9 in gastrointestinal tumorigenesis: A comprehensive review

Figure 3 Phosphatidylinositol 3-kinase/protein kinase B pathway is involved in cell growth, differentiation, and tumorigenesis. When the ligand binds to the membrane receptor, the receptor and myosin heavy chain 9 activate phosphatidylinositol 3-kinase, which then catalyzes the formation of phosphatidylinositol-3-phosphate from phosphatidylinositol 4,5-biphosphate on the inner surface of the membrane. As the second messenger, phosphatidylinositol-3-phosphate further activates protein kinase B. Protein kinase B can activate the downstream mammalian target of rapamycin pathway, which can phosphorylate and activate S6 kinase 1 and 4E-binding protein, and finally participate in gene expression. PI3K: Phosphatidylinositol 3-kinase; AKT: Protein kinase B; mTOR: Mammalian target of rapamycin. MYH9: Myosin heavy chain 9; PI3K: Phosphatidylinositol 3-kinase; AKT: Protein kinase B; mTOR: Mammalian target of rapamycin; PIP2: Phosphatidylinositol 4,5-biphosphate; PIP3: Phosphatidylinositol-3-phosphate; S6K1: S6 kinase 1; 4EBP: 4E-binding protein; PTEN: Phosphatase and tensin homolog.