Heat shock protein-90 (Hsp90) is an essential molecular chaperone in eukaryotes involved in maintaining the stability and activity of numerous signalling proteins, also known as clients. Hsp90 ATPase activity is essential for its chaperone function and it is regulated by co-chaperones. Here we show that the tumour suppressor FLCN is an Hsp90 client protein and its binding partners FNIP1/FNIP2 function as co-chaperones. FNIPs decelerate the chaperone cycle, facilitating FLCN interaction with Hsp90, consequently ensuring FLCN stability. FNIPs compete with the activating co-chaperone Aha1 for binding to Hsp90, thereby providing a reciprocal regulatory mechanism for chaperoning of client proteins. Lastly, downregulation of FNIPs desensitizes cancer cells to Hsp90 inhibitors, whereas FNIPs overexpression in renal tumours compared with adjacent normal tissues correlates with enhanced binding of Hsp90 to its inhibitors. Our findings suggest that FNIPs expression can potentially serve as a predictive indicator of tumour response to Hsp90 inhibitors.
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http://dx.doi.org/10.1038/ncomms12037 | DOI Listing |
Curr Cancer Drug Targets
January 2025
Human Genetics Laboratory, Institute of Natural Sciences, Federal University of Alfenas (UNIFAL-MG), Alfenas, 37130-001, MG, Brazil.
Histone Deacetylase 6 (HDAC6) is an intriguing therapeutic target in cancer re-search, distinguished as the only HDAC family member predominantly located in the cyto-plasm. HDAC6 features two catalytic domains and a unique ubiquitin-binding domain, which sets it apart from other HDACs. Beyond its role in histone deacetylation, HDAC6 targets vari-ous nonhistone substrates, such as α-tubulin, cortactin, Heat Shock Protein 90 (HSP90), and Heat Shock Factor 1 (HSF1).
View Article and Find Full Text PDFBreast Cancer Res Treat
January 2025
Rafet Kayış Faculty of Engineering, Department of Genetics and Bioengineering, Alanya Alaaddin Keykubat University, Antalya, Turkey.
Purpose: The incidence of breast cancer has been increasing in recent years, and monotherapy approaches are not sufficient alone in the treatment of breast cancer. In the combined therapy approach, combining two or three different agents in lower doses can mitigate the side effects on living cells and tissues caused by high doses of chemical agents used alone. ABT-263 (navitoclax), a clinically tested Bcl-2 family protein inhibitor, has shown limited success in clinical trials due to the development of resistance to monotherapy in breast cancer cells.
View Article and Find Full Text PDFMolecules
December 2024
Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche "STEBICEF", University of Palermo, Viale delle Scienze, Ed. 17, 90128 Palermo, Italy.
Breast cancer remains one of the most prevalent and lethal malignancies in women, particularly the estrogen receptor-positive (ER+) subtype, which accounts for approximately 70% of cases. Traditional endocrine therapies, including aromatase inhibitors, selective estrogen receptor degraders/antagonists (SERDs), and selective estrogen receptor modulators (SERMs), have improved outcomes for metastatic ER+ breast cancer. However, resistance to these agents presents a significant challenge.
View Article and Find Full Text PDFNeuromolecular Med
January 2025
Department of Neurology, Second Affiliated Hospital of Army Medical University (Xinqiao Hospital), Chongqing, China.
J Med Chem
January 2025
The Center for Basic Research and Innovation of Medicine and Pharmacy (MOE), School of Pharmacy, Second Military Medical University (Naval Medical University), 325 Guohe Road, Shanghai 200433, China.
Invasive candidiasis has attracted global attention with a high incidence and mortality. Current antifungal drugs are limited by unfavorable therapeutic efficacy, significant hepatorenal toxicity, and the development of drug resistance. Herein, we designed the first generation of lanosterol 14α-demethylase (CYP51)/heat shock protein 90 (Hsp90) dual inhibitors on the basis of antifungal synergism.
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