Inauhzin

Inauhzin is a dual SirT1/IMPDH2 inhibitor, and acts as an activator p53, used in the research of cancer.

Signaling Pathways >> Apoptosis >> MDM-2/p53

Signaling Pathways >> Cell Cycle/DNA Damage >> Sirtuin

Signaling Pathways >> Epigenetics >> Sirtuin

Research Areas >> Cancer

SIRT1

MDM-2/p53

IMPDH2

Inauhzin (10 µM) induces p53 levels as effectively as actinomycin D (10 nM), and mediates p53-dependent cytotoxicity through its specific functional groups in human lung carcinoma H460 cells. Inauhzin (2 µM) induces p53 level and activity as well as p53-dependent apoptosis. Inauhzin also stabilizes p53 and inhibits its ubiquitylation. Inauhzin induces acetylation of p53 in H460 cells, but not tubulin, which is affected by knockdown of SIRT1[1]. Inauhzin (0-2 µM) significantly enhances the expression level and activity of p53 in HCT116p53+/+ cells and enhances the expression level and activity of p53 in H460 cells in a dose-dependent manner. Inauhzin and Nutlin-3 demonstrate synergistic cytotoxicity in the Nutlin-3 low-sensitive cells. Inauhzin and Nutlin-3 synergistically induce p53-dependent apoptosis[2]. Inauhzin targets both SirT1 and IMP dehydrogenase 2 (IMPDH2), and acts as a potent p53 activator[3].

Inauhzin (30 mg/kg, i.p.) effectively induces apoptosis and suppresses tumour growth of H460 xenograft harbouring p53[1]. Inauhzin (30 mg/kg, i.p.) reduces the HCT116 tumor volume by appr 70%. Inauhzin (15 mg/kg) in combination with 150 mg/kg of Nutlin-3 demonstrates a significant synergy on p53 induction, apoptosis and tumor suppression of HCT116p53+/+ xenografts[2].

The cell counting kit is used to assess cell growth. Cell suspensions are seeded at 5000 cells per well in 96-well culture plates and incubated overnight at 37°C. Compounds are added into the plates and incubated at 37°C for 72 h. Cell growth inhibition is determined by adding WST-8 at a final concentration of 10% to each well, and the absorbance of the samples is measured at 450 nm using a Microplate Reader[1].

Five-weeks-old female SCID mice are housed in a BSL2 environment. Mice are subcutaneously inoculated with 5×106 H460 or 3×106 HCT116 cells. Tumour growth is monitored every other day with electronic digital calipers in two dimensions. Tumour volume is calculated with the formula: tumour volume (mm3) = (length × width2)/2. When the mean tumour volume reaches approximately 100 mm3 after 7-9 days, animals are dosed by i.p. injection with vehicle (5% DMSO) or Inauhzin. Inhibition of tumour growth is calculated on the last day of treatment. To detect p53 activation in vivo, tumours are harvested and disrupted in RIPA buffer containing a protease inhibitor mixture. Tumour lysates are analysed by IB. Cell proliferation in tumours is assessed by BrdU labeling followed by Immunostaining. 200 mg/kg body weight of BrdU is administrated to mice via i.p. injection 2 h before mice are sacrificed. Apoptosis is examined by TUNEL staining, using the Fluorescein In situ cell death detection kit[1].

[1]. Zhang Q, et al. A small molecule Inauhzin inhibits SIRT1 activity and suppresses tumour growth through activation of p53. EMBO Mol Med. 2012 Apr;4(4):298-312.

[2]. Zhang Y, et al. Inauhzin and Nutlin3 synergistically activate p53 and suppress tumor growth. Cancer Biol Ther. 2012 Aug;13(10):915-24.

[3]. Nguyen D, et al. Reviving the guardian of the genome: Small molecule activators of p53. Pharmacol Ther. 2017 Oct;178:92-108.

Selisistat (EX 527) | Pifithrin-α hydrobromide | RG7388 | Nicotinamide | Nutlin-3a | SRT1720 HCl | AMG232 | Sirtinol | 3-TYP | Pifithrin-β (hydrobromide) | Stylomycin aminonucleoside | RG7112 | SRT 2104 | Fisetin | APR-246