Description
BAY 87-2243 (1227158-85-1) potently inhibits HIF-1 reporter gene activity (IC50= 0.7 nM) and CA9 protein expression (IC50= 2.0 nM).1It inhibited HIF-1α and HIF-2α protein accumulation in hypoxic H460 cells and reduced tumor weight in nude mice inoculated with H460 cells. BAY 87-2243 potently inhibits mitochondrial complex I activity (IC50= 10 nM in mitochondria isolated from PC3 cells) leading to its HIF-1 effects. It has no effect on mitochondrial complex III. BAY 87-2243 reduced melanoma tumor growthviaits targeting of mitochondrial complex I.2,3
Synthesis
The general procedure for the synthesis of 5-(1-((2-(4-cyclopropylpiperazin-1-yl)pyridin-4-yl)methyl)-5-methyl-1H-pyrazol-3-yl)-3-(4-(trifluoromethoxy)phenyl)-1 ,2,4-oxadiazole from 1-ethoxy-1-trimethylsilanyloxycyclopropane and the compound (CAS:1227158-84-0) was as follows: in Example 65 Example 65, 66 mL (1.15 mmol) of glacial acetic acid, 13.9 g of dry powdered molecular sieves (3 ) and 139 mL (0.692 mol) of 1-ethoxy-1-(trimethylmethylsilyl)hydroxycyclopropane were sequentially added to a solution of 56.0 g (0.115 mol) of the compound of Example 64 in 1.13 L of methanol. After stirring for 10 minutes at room temperature, 21.7 g (0.346 mol) of solid sodium cyanoborohydride was added. The mixture was heated under reflux conditions for 1 hour. After cooling to room temperature, the undissolved material was removed by filtration and the filtrate was concentrated on a rotary evaporator. The residue was dissolved in 1 L of ethyl acetate and washed twice with 750 mL of saturated sodium bicarbonate solution for about 1 hour each time, followed by 750 mL of saturated sodium chloride solution. After drying with anhydrous sodium sulfate, the mixture was filtered and the solvent was removed on a rotary evaporator. The residue (53 g) was recrystallized from a boiling mixture of 293 mL of ethanol and 59 mL of water. After crystallization was complete (about 20 hours at room temperature), the mixture was filtered. The solid was washed with 36 mL of ethanol/water (5:1) and then dried under high vacuum. 26.4 g of the target compound was obtained as the first product. The crystallized mother liquor was concentrated and another 20.3 g of product was obtained as formate by preparative HPLC (Method N). To release the base, a suspension of formate in 1 L of ethyl acetate was washed sequentially with 200 mL of saturated sodium bicarbonate solution, water and saturated sodium chloride solution. After drying with anhydrous sodium sulfate, it was filtered and concentrated. The residue (13 g) was recrystallized from a boiling mixture of 80 mL ethanol and 16 mL water. After crystallization was complete (about 4 hours at room temperature), the solid was filtered and dried to give an additional 11.2 g of the target compound (total yield 37.6 g, 62% of theoretical yield). Melting point: 140 °C. 1H-NMR (400 MHz, CDCl3, δ/ppm): 8.26 (d, 2H), 8.13 (d, 1H), 7.33 (d, 2H), 6.83 (s, 1H), 6.33 (d, 1H), 6.32 (s, 1H), 5.35 (s, 2H), 3.47 (dd, 4H), 2.69 ( dd, 4H), 2.30 (s, 3H), 1.65-1.60 (m, 1H), 0.48-0.42 (m, 4H).LC/MS (Method D, ESIpos): rt = 1.91 min, m/z = 526 [M + H]+.
Enzyme inhibitor
This Hif1a inhibitor (FW = 525.53 g/mol; CAS 1227158-85-1; Solubility: <1 mg/mL DMSO or H2O) targets the transcription factor hypoxia-inducible factor-1 (HIF-1), which plays an essential role in tumor development, tumor progression, and resistance to chemo- and radiotherapy. BAY 87-2243 inhibits HIF-1α and HIF-2α accumulation under hypoxic conditions in the H460 Non-Small Cell Lung Cancer (NSCLC) cell line but is without effect on HIF-1α protein levels that are induced by such hypoxia mimetics asdesferrioxamine or cobalt chloride. BAY 87-2243 has no effect on HIF target gene expression levels in RCC4 cells lacking Von Hippel-Lindau (VHL) activity; nor does it affect the activity of HIF prolyl hydroxylase-2. Antitumor activity of BAY 87-2243, suppression of HIF-1α protein levels, and reduction of HIF-1 target gene expression in vivo have been demonstrated in a H460 xenograft model. BAY 87-2243 does not inhibit cell proliferation under standard conditions. Upon glucose depletion, a condition favoring mitochondrial ATP generation as energy source, BAY 87-2243 inhibits cell proliferation in the low-nM range. In a mouse model for BRAF mutant melanoma, BAY 87-2243-mediated complex I inhibition induces melanoma cell death in vitro and reduces melanoma tumor growth in various mouse models in vivo. This effect is mediated through BAY 87-2243- induced stimulation of mitochondrial ROS production, leading to oxidative damage and subsequent cell death. BAY 87-2243 displays increased anti tumor efficacy compared to single agent treatment, when combined with the BRAF inhibitor vemurafenib in nude mice with BRAF mutant melanoma xenografts.
in vivo
Nude mice are inoculated with H460 cells subcutaneously and after tumors have been established, animals are treated with BAY 87-2243 (0.5, 1, 2, and 4 mg/kg) for 3 weeks by daily oral gavage. BAY 87-2243 reduced tumor weight dose dependently in line with a dose-dependent reduction of the mRNA expression levels of the HIF-1 target genes CA9, ANGPTL4, and EGLN3, whereas the mRNA expression levels of hypoxia-insensitive EGLN2 gene and of HIF-1α itself are not affected by compound treatment in vivo[1].
References
[1] PETER ELLINGHAUS. BAY 87-2243, a highly potent and selective inhibitor of hypoxia-induced gene activation has antitumor activities by inhibition of mitochondrial complex I[J]. Cancer Medicine, 2013, 2 5: 611-624. DOI:
10.1002/cam4.112[2] LAURA SCHÖCKEL. Targeting mitochondrial complex I using BAY 87-2243 reduces melanoma tumor growth.[J]. Cancer & Metabolism, 2015, 3: 11. DOI:
10.1186/s40170-015-0138-0[3] FARHAN BASIT. Mitochondrial complex I inhibition triggers a mitophagy-dependent ROS increase leading to necroptosis and ferroptosis in melanoma cells[J]. Cell Death & Disease, 2017, 8 3: e2716-e2716. DOI:
10.1038/cddis.2017.133
