• What is KIT?
  • KIT in Acute Myeloid Leukemia
  • Clinical Trials

KIT

KIT (also called CD117) is a receptor tyrosine kinase (RTK) expressed on a wide variety of cell types. The ligand for KIT is stem cell factor (SCF). The binding of SCF to the extracellular domain of KIT induces receptor dimerization and activation of downstream signaling pathways, including the PI3K-AKT-mTOR pathway, the RAS-RAF-MEK-ERK pathway, and the signal transducer and activator of transcription 3 (acute-phase response factor), or STAT3, pathway, all of which are involved in mediating pro-growth and pro-survival signals within the cell (Figure 1).

Mutant KIT has been implicated in the pathogenesis of several cancers including melanoma, acute leukemia, and gastrointestinal stromal tumor (GIST; Heinrich et al. 2003; Hirota et al. 1998).

The discovery of KIT mutations revolutionized the treatment of GISTs. The use of imatinib mesylate (Gleevec), an oral KIT inhibitor leads to rapid, substantial, and durable tumor responses (Demetri et al. 2002). Not all KIT mutations are associated with equal sensitivity to imatinib (Heinrich et al. 2008); some are more sensitive to second-generation KIT inhibitors.

kit-signaling.png

Figure 1.
Schematic of KIT signaling pathways. The binding of SCF, to the KIT receptor tyrosine kinase results in activation of the MAPK signaling pathway (RAS-RAF-MEK-ERK), the PI3K pathway (PI3K-AKT-mTOR), and the STAT3 pathway. The letter "K" within the schema denotes the tyrosine kinase domain.

Related Pathways

Contributors: Christine M. Lovly, M.D., Ph.D., Jeff Sosman, M.D., William Pao, M.D., Ph.D. (through April 2014)

Suggested Citation: Lovly, C., J. Sosman, W. Pao. 2015. KIT. My Cancer Genome https://www.padiracinnovation.org/content/disease/acute-myeloid-leukemia/kit/?tab=0 (Updated December 7).

Last Updated: December 7, 2015

KIT in Acute Myeloid Leukemia

KIT is mutated in 8.0% of acute myeloid leukemia (COSMIC). Oncogenic KIT mutations occur primarily in core binding factor (CBF) AML (Ashman and Griffith 2013). KIT mutations occur primarily in exon 17 and affect the activation loop of the kinase domain (Ashman and Griffith 2013; Malaise et al. 2009). These changes result in improved survival and growth of tumor cells (Ashman and Griffith 2013). KIT mutations fall into class I of the “two-hit” theory of leukemogenesis (Naoe and Kiyoi 2013). ​

Contributors: Scott Wheeler, Ph.D. (through June 2014), Adam Seegmiller, M.D., Ph.D., Cindy L. Vnencak-Jones, Ph.D.

Suggested Citation: Wheeler, S., A. Seegmiller, C. Vnencak-Jones. 2013. KIT in Acute Myeloid Leukemia. My Cancer Genome https://www.padiracinnovation.org/content/disease/acute-myeloid-leukemia/kit/ (Updated September 9).

Last Updated: September 9, 2013

My Cancer Genome has released its new and improved cancer clinical trials search tool on our beta website. Please visit beta.padiracinnovation.org to check it out!

Disclaimer: The information presented at padiracinnovation.org is compiled from sources believed to be reliable. Extensive efforts have been made to make this information as accurate and as up-to-date as possible. However, the accuracy and completeness of this information cannot be guaranteed. Despite our best efforts, this information may contain typographical errors and omissions. The contents are to be used only as a guide, and health care providers should employ sound clinical judgment in interpreting this information for individual patient care.