Synthesis and Evaluation of the Tumor Cell Growth Inhibitory Potential of New Putative HSP90 Inhibitors

Abstract

Background: Heat shock protein 90 (HSP90) is a well-known target for cancer therapy. In a previous work, some of us have reported a series of 3-aryl-naphtho[2,3-d]isoxazole-4,9-diones as inhibitors of HSP90. Methods: In the present work, various compounds with new chromenopyridinone and thiochromenopyridinone scaffolds were synthesized as potential HSP90 inhibitors. Their binding affinity to HSP90 was studied in vitro. Selected compounds (5 and 8) were further studied in various tumor cell lines regarding their potential to cause cell growth inhibition, alter the cell cycle profile, inhibit proliferation, and induce apoptosis. Their effect on HSP90 client protein levels was also confirmed in two cell lines. Finally, the antitumor activity of compound 8 was studied in A431 squamous cell carcinoma xenografts in nude mice. Results: Our results indicated that treatment with compounds 5 and 8 decreased the proliferation of tumor cell lines and compound 8 induced apoptosis. In addition, these two compounds were able to downregulate selected proteins known as “clients” of HSP90. Finally, treatment of xenografted mice with compound 5 resulted in a considerable dose-dependent inhibition of tumor growth. Conclusions: Our results show that two new compounds with a chromenopyridinone and thiochromenopyridinone scaffold are promising putative HSP90 inhibitors causing tumor cell growth inhibition.

BIRC3 and BIRC5: multi‐faceted inhibitors in cancer

“…NSCLC targeted therapy had also been demonstrate to benefit of Hsp90 inhibition in tumors harboring EGFR mutations [23,24]. Notably, BIRC5 (survivin) is a client protein of Hsp90 chaperone and results downregulated upon Hsp90 pharmacological inhibition in cancer cells [25,26].…”

Pirfenidone Sensitizes NCI-H460 Non-Small Cell Lung Cancer Cells to Paclitaxel and to a Combination of Paclitaxel with Carboplatin

“…Cell proliferation was assessed using the 5-bromo-2′-deoxyuridine (BrdU) incorporation assay, according to the described protocol [ 37 , 44 , 45 ]. For that, NCI-H460 cells were plated in 6-well plates at a previously determined optimal cell concentration (5 × 10 4 cells/mL) and incubated for 24 h. Then, cells were subjected to the desired treatments for 48 h. Nearly 4 h before cell collection, cells of each condition were incubated with BrdU (Merck Life Science, Darmstadt, Germany; B5002) at a final concentration of 10 μM.…”

“…Cell cycle profile was assessed by flow cytometry following propidium iodide (PI) staining, according to the described protocol [ 37 , 38 , 44 , 45 ]. For that, NCI-H460 cells were plated in 6-well plates at a previously determined optimal cell concentration (5 × 10 4 cells/mL) and incubated for 24 h. Then, cells were treated with the desired conditions for 48 h. After the incubation period, cells of each condition were collected, centrifuged (1200 rpm for 5 min at 4 °C) and fixed with ice-cold 70% ethanol (Fischer Scientific, Hampton, NH, USA; E/0650DF/C17) at 4 °C for a period of at least 12 h. Then, cells were centrifuged at the previously described conditions and each cell pellet was resuspended in a PBS solution containing 0.1 mg/mL RNase A (Invitrogen, Waltham, MA, USA; 12091021) and 5 µg/mL PI (Merck Life Science, Darmstadt, Germany; 537060) and kept in the dark for at least 30 min.…”

“…Cell death was assessed using the Annexin V-FITC Apoptosis Detection Kit (eBioscience™, Thermo Fisher Scientific, Waltham, MA, USA; BMS500FI), according to manufacturer’s instructions and to the previously described protocol [ 37 , 38 , 45 ]. For that, NCI-H460 cells were plated in 6-well plates, and incubated for 24 h. Then, cells were exposed to the desired drug treatments for 48 h. Nearly 1 h before cell collection, pure ethanol was added to the well corresponding to the positive control for necrosis.…”

DBU-Promoted Cascade Selective Nucleophilic Addition/C–C Bond Cleavage/Hetero-Diels–Alder Reactions of 2-Amino-4H-chromen-4-ones with β-Nitrostyrenes and/or Aryl Aldehydes: Access to 5H-Chromeno[2,3-b]pyridin-5-ones

“…Recently, the design and construction of the chroman-fused polycyclic structures have been a hot research topic in the investigations of many natural products and bioactive substances . Many chroman-fused pyridines showed significant biological activity including anti-inflammatory and antiplatelet, analgesic, antipyretic, and bronchodilator activities and utilized as muscle relaxant, diuretic agents, antitumor agents, − inhibitors of β-site amyloid precursor protein cleaving enzyme for the treatment of Alzheimer’s disease, , selective glucocorticoid receptor modulators, inhibitor of TBK1 and IKKε, and antiobesity drugs . Their derivatives also were used as a herbicide or plant growth regulator .…”