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Updated: Aug 19, 2026
Molecular and Immunologic Techniques in a Genetically Engineered Mouse Model of Gastrointestinal Stromal Tumor
Published on: May 2, 2022
A clinical and biological overview of gastrointestinal stromal tumors
Myrna Candelaria1, Jaime de la Garza, Alfonso Duenas-Gonzalez
1Division of Clinical Research, National Cancer Institute, Mexico City. mcandelariah@incan.edu.mx
Abstract:
In the last few years a body of knowledge has been generated on the molecular basis of gastrointestinal stromal tumors (GIST). These mesenchymal tumors are characterized by the expression of KIT protein and because they have an activating mutation in a class III receptor tyrosine kinase gene (KIT or PDGFRA). Several KIT-activating mutations, which are largely responsible for the development of this tumor, promote cell survival, proliferation, and migration through different pathways such as MAPK p42/44, AKT, S6K, STAT1, and STAT3. Likewise, gene-activating mutations in the gene PDGFRalpha which codes for the receptor tyrosine kinase, Platelet-derived growth factor receptor alpha have been identified in GIST lacking KIT mutations. This means that KIT and PDGFRalpha mutations appear to be alternative and mutually exclusive oncogenic pathways for GIST development. These tumors may occur anywhere along the gastrointestinal tract (GI). The most frequently involved sites are stomach and small intestine. They are typically chemo- and radioresistant. The discovery of a specific inhibitor of this tyrosine kinase, imatinib mesylate, has radically changed the prognosis of patients with unresectable disease. Only 4 yr after the first patient was successfully treated with imatinib, multiple phase II and III trials have been published and, currently, imatinib mesylate is the only effective systemic treatment available of these tumors. Response rates are approximately 70-90% with acceptable toxicity. GIST are the first model of a solid tumor efficiently treated with a molecular-targeted agent. This review summarizes the clinical and biological aspects of this unique neoplasm.
Insights
Gastrointestinal stromal tumors (GIST) are driven by KIT or PDGFRA mutations. Targeted therapy with imatinib mesylate offers effective treatment for these typically chemo- and radioresistant neoplasms.
Area of Science:
- Oncology
- Molecular Biology
- Gastroenterology
Background:
- Gastrointestinal stromal tumors (GIST) are mesenchymal neoplasms.
- GIST are characterized by KIT protein expression and activating mutations in KIT or PDGFRA genes.
- These mutations activate oncogenic pathways, promoting tumor cell survival and proliferation.
Purpose of the Study:
- To review the clinical and biological aspects of GIST.
- To highlight the molecular basis of GIST development.
- To discuss the impact of targeted therapy on GIST prognosis.
Main Methods:
- Literature review of clinical and biological studies on GIST.
- Analysis of molecular mechanisms underlying GIST pathogenesis.
- Evaluation of treatment outcomes with imatinib mesylate.
Main Results:
- KIT and PDGFRA mutations are mutually exclusive oncogenic drivers in GIST.
- GIST commonly occur in the stomach and small intestine and are resistant to conventional therapies.
- Imatinib mesylate demonstrates high response rates (70-90%) and acceptable toxicity in GIST patients.
Conclusions:
- GIST represent a paradigm for molecularly targeted cancer therapy.
- Imatinib mesylate has revolutionized GIST treatment, offering a highly effective systemic option.
- Understanding the molecular basis of GIST is crucial for developing novel therapeutic strategies.
