Molecular pathway of anticancer effect of next-generation HSP90 inhibitors XL-888 and Debio0932 in neuroblastoma cell line.

Neuroblastoma is a common nervous system tumor in childhood, and current treatments are not adequate. HSP90 is a molecular chaperone protein that plays a critical role in the regulation of cancer-related proteins. HSP90 inhibition may exert anticancer effects by targeting cancer-related processes such as tumor growth, cell proliferation, metastasis, and apoptosis. Therefore, HSP90 inhibition is a promising strategy in the treatment of various types of cancer, and the development of next-generation inhibitors could potentially lead to more effective and safer treatments. XL-888 and Debio0932 is a next-generation HSP90 inhibitor and can inhibit the correct folding and stabilization of client proteins that cancer-associated HSP90 helps to fold correctly. In this study, we aimed to investigate the comprehensive molecular pathways of the anticancer activity of XL-888 and Debio0932 in human neuroblastoma cells SH-SY5Y. The cytotoxic effects of XL-888 and Debio0932 on the neuroblastoma cell line SH-SY5Y cells were evaluated by MTT assay. Then, the effect of these HSP90 inhibitors on the expression of important genes in cancer was revealed by Quantitative Real Time Polymerase Chain Reaction (qRT-PCR) method. The qRT-PCR data were evaluated using Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) biological process tools. Finally, the effect of HSP90 inhibitors on HSP27, HSP70 and HSP90 protein expression was investigated by Western blotting analysis. The results revealed that XL-888 and Debio0932 had a role in regulating many cancer-related pathways such as migration, invasion, metastasis, angiogenesis, and apoptosis in SH-SY5Y cells. In conclusion, it shows that HSP90 inhibitors can be considered as a promising candidate in the treatment of neuroblastoma and resistance to chemotherapy.

Enhancing therapeutic efficacy in breast cancer: a study on the combined cytotoxic effects of doxorubicin and MPC-3100.

PURPOSE: Combination therapy is a strategy aimed at the combined use of agents targeting different mechanisms in cancer treatment. This study aimed to examine the cytotoxic and apoptotic effects of the traditional chemotherapeutic agent doxorubicin (DOX) and the next-generation HSP90 inhibitor MPC-3100 on breast cancer cell lines. METHODS: Firstly, molecular docking analyses were performed, and then the MTT test was conducted to evaluate the individual and combined cytotoxic effects of DOX and MPC-3100 on MCF-7 and MDA-MB-231 breast cancer cell lines. The effect of two drugs combination was assessed by the Chou and Talalay approach. To further investigate the underlying molecular mechanism responsible for this synergistic effect, the gene expression levels of apoptotic and heat shock proteins (HSP), as well as the protein expression levels, were examined using quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) and Western Blotting, respectively. RESULTS: Based on the molecular docking results, it was observed that MPC-3100 specifically binds to the ATP binding pocket of Hsp90, exhibiting an estimated free binding energy of -7.9 kcal/mol. MTT results indicated that both DOX and MPC-3100, as well as their combination, exhibited dose-dependent cytotoxicity. The drug combination showed a synergistic effect on both MCF-7 and MDA-MB-231 cell lines. Finally, the investigated molecular mechanism demonstrated that the combination of DOX and MPC-3100 induced apoptosis in breast cancer cells more efficiently than either drug alone. CONCLUSIONS: This study showed a possible coordinated mechanism of action between DOX and MPC-3100, pointing to the possibility of a more effective therapeutic strategy for breast cancer therapy.

Debio-0932, a second generation oral Hsp90 inhibitor, induces apoptosis in MCF-7 and MDA-MB-231 cell lines.

Heat shock protein 90 (Hsp90) is a key chaperone that is abnormally expressed in cancer cells, and therefore, designing novel compounds to inhibit chaperone activities of the Hsp90 is a promising therapeutic approach for cancer drug discovery. Debio-0932 is a second-generation Hsp90 inhibitor that exhibited promising anticancer activity against a wide variety of cancer types with a strong binding affinity for Hsp90 and high oral bioavailability. Anticancer activities of the Debio-0932 were tested in MCF-7 and MDA-MB-231 cell lines. Molecular docking results indicated that Debio-0932 was selectively bound to the ATP binding pocket of the Hsp90 with an estimated free energy of binding - 7.24 kcal/mol. Antiproliferative activity of Debio-0932 was determined by XTT assay and Debio-0932 exhibited a cytotoxic effect on MCF-7 and MDA-MB-231 cells in a time and dose-depended manner. Apoptosis inducer role of Debio-0932 was evaluated in MCF-7 and MDA-MB-231 cells with fluorometric apoptosis/necrosis detection kit. Treatment with Debio-0932 stimulated apoptosis in both breast cancer cell lines. mRNA and protein expression levels of Bax, Bcl-2 and Casp-9 were determined in MCF-7 and MDA-MB-231 cells by RT-PCR and Western blotting respectively. Debio-0932 stimulated the down-regulation of anti-apoptotic protein Bcl-2 and the up-regulation of apoptotic protein Bax and cleavage of Casp-9 in cancer cells. Moreover, the anti-invasive potential of Debio-0932 was evaluated in endothelial cells (HUVEC) by wound-healing assay. Debio-0932 decreased the migration of HUVEC cells as compared to the control group. These results indicate that Debio-0932 is a promising compound to treat triple-negative breast cancer and hormone receptor-positive breast cancer, and their metastases.