The Development of Novel Small Molecules as Receptor Tyrosine Kinase Inhibitors for the Treatment of Cancer

Receptor Tyrosine Kinase (RTK) is a type of cell surface receptor that is involved in signalling, growth and proliferation of cells. In cancer cells, overexpression or gain-of-function mutations causes RTKs to become constitutively active, causing uncontrolled growth and proliferation of cells. Studies of the common RTKs mutations can lead to the potential treatment of cancer through developing novel small molecules which selectively target the mutated of RTKs. This review summarizes the diseases associated with four different mutated RTKs, Bcr-Abl, Anaplastic Lymphoma Kinase (ALK), Fms-Like Tyrosine Kinase 3 (FLTK3) and Fibroblast Growth Factor Receptor 3 (FGFR3). It will also discuss the small molecules developed to specifically inhibit each of these mutated RTKs. Being on different stages of the drug development process, they have so far been shown to be effective at RTK inhibition, demonstrating their potential as therapeutic anti-cancer agents. Though a large numbers of tests and clinical trials are still needed before these molecules can be proven safe and efficacious in human, the continuous studies on small molecule inhibitors of RTKs will lead to new understandings of cellular pathways and hopefully more breakthrough therapies for the treatment of cancer.