Proteasome Inhibition Suppresses KIT-Independent Gastrointestinal Stromal Tumors Via Targeting Hippo/YAP/Cyclin D1 Signaling
| Autor: | Nan Ni, Li Yuan, Ting Chen, Nacef Bahri, Wen-Bin Ou, Liangliang Xu, Boshu Sun, Yuehong Wu |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Pharmacology
Hippo signaling pathway Stromal cell Bortezomib hippo pathway Cell bortezomib cyclin D1 RM1-950 Cell cycle Biology Cyclin D1 medicine.anatomical_structure Hippo signaling KIT-independent GIST Proteasome inhibitor medicine Cancer research YAP/TAZ Pharmacology (medical) Therapeutics. Pharmacology neoplasms medicine.drug Original Research |
| Zdroj: | Frontiers in Pharmacology Frontiers in Pharmacology, Vol 12 (2021) |
| ISSN: | 1663-9812 |
| Popis: | Purpose: Gastrointestinal stromal tumors (GISTs) are the most common malignant tumor of mesenchymal origin of the digestive tract. A yet more challenging resistance mechanism involves transition from oncogenic KIT to a new imatinib-insensitive oncogenic driver, heralded by loss of KIT expression. Our recent studies have shown that inhibition of cyclin D1 and Hippo signaling, which are overexpressed in KIT-independent GIST, is accompanied by anti-proliferative and apoptosis-promoting effects. PRKCQ, JUN, and the Hippo/YAP pathway coordinately regulate GIST cyclin D1 expression. Thus, targeting of these pathways could be effective therapeutically for these now untreatable tumors.Methods: Targeting cyclin D1 expression of small molecular drugs was screened by a cell monolayer growth and western blotting. The biologic mechanisms of bortezomib to KIT-independent GISTs were assessed by immunoblotting, qRT-PCR, cell viability, colony growth, cell cycle analysis, apoptosis, migration and invasiveness.Results: In the initial small molecular inhibitor screening in KIT-independent GIST62, we found that bortezomib-mediated inhibition of the ubiquitin-proteasome machinery showed anti-proliferative effects of KIT-independent GIST cells via downregulation of cyclin D1 and induction of p53 and p21. Treatment with proteasome inhibitor, bortezomib, led to downregulation of cyclin D1 and YAP/TAZ and an increase in the cleaved PARP expression in three KIT-independent GIST cell lines (GIST48B, GIST54, and GIST226). Additionally, it induced p53 and p21 expression in GIST48B and GIST54, increased apoptosis, and led to cell cycle G1/G2-phase arrest, decreased cell viability, colony formation, as well as migration and invasiveness in all GIST cell lines.Conclusion: Although our findings are early proof-of-principle, there are signs of a potential effective treatment for KIT-independent GISTs, the data highlight that targeting of cyclin D1 and Hippo/YAP by bortezomib warrants evaluation as a novel therapeutic strategy in KIT-independent GISTs. |
| Databáze: | OpenAIRE |
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