What molecular targets does imatinib mainly act on in the human body?

Imatinib/Gleevec is a classic targeted therapy drug. Its greatest feature is that it selectively inhibits specific tyrosine kinase molecules and blocks signal transduction pathways, thereby inhibiting the growth and spread of tumor cells. Its main target is BCR-ABL fusion protein, which is a key molecule in the pathogenesis of chronic myelogenous leukemia (CML). In normal hematopoietic cells, ABL tyrosine kinase has the function of regulating cell proliferation. However, when the BCR and ABL genes undergo chromosomal translocation to form a fusion protein, the enzyme continues to be activated, leading to abnormal proliferation of leukemia cells. Imatinib blocks the growth of cancer cells by binding to the ABL kinase domain and inhibiting its phosphorylation activity.

In addition toBCR-ABL, imatinib can also inhibit two types of tyrosine kinases, KIT (CD117) and PDGFR (platelet-derived growth factor receptor). This mechanism also makes it effective in gastrointestinal stromal tumors (GIST), because this type of tumor is often related to KIT gene mutations. In addition, imatinib's inhibitory effect on PDGFRα and PDGFRβ has also expanded its use in some rare soft tissue tumors and myeloproliferative diseases.

From the perspective of target mechanism, the precision of imatinib lies in its high-affinity binding to specific mutant proteins, which avoids extensive toxic damage to normal cells. Because of this, imatinib has become the founder of molecular targeted therapy and pioneered the transformation of tumor treatment from the "chemotherapy era" to "precision medicine". Its clear target and specific action make it well tolerated and capable of long-term control of disease progression in clinical applications. At present, many countries continue to promote research on the resistance mechanisms of imatinib, providing a basis for the subsequent development of second- and third-generation TKI drugs.

Reference materials:https://www.gleevec.com/