Pifithrin-α hydrobromide

Names

[ Name ]:
Pifithrin-α hydrobromide

[Synonym ]:
Pifithrin-α hydrobromide
Pifithrin-a
1-(4-methylphenyl)-2-(4,5,6,7-tetrahydro-2-imino-3(2H)- benzothiazolyl)ethanone hydrobromide
2-imino-3-phenacyl-4,5,6,7-tetrahydrobenzothiazole hydrobromide
PFT-α
Pifithrin-α
PFTalpha
Pifithrin-|A
Ethanone, 1-(4-methylphenyl)-2-(4,5,6,7-tetrahydro-2-imino-3(2H)-benzothiazolyl)-, hydrobromide (1:1)
2-(2-Imino-4,5,6,7-tetrahydro-1,3-benzothiazol-3(2H)-yl)-1-(4-methylphenyl)ethanone hydrobromide (1:1)
Pifithrin-Alpha
MFCD00417851
Pifithrin-Alpha (hydrobromide)
Pifithrin-α (hydrobromide)
Pifithrin

Biological Activity

[Description]:

Pifithrin-α hydrobromide is a p53 inhibitor which blocks its transcriptional activity and prevents cells from apoptosis.

[Related Catalog]:

Signaling Pathways >> Immunology/Inflammation >> Aryl Hydrocarbon Receptor

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

Research Areas >> Cancer

[Target]

p53[1] AhR[2]

[In Vitro]

Pifithrin-α (PFT-α) hydrobromideis a water-soluble compound that could suppress p53 protein transcription. Pifithrin-α can suppress glucose oxidase (GOX)-induced p53 protein increase in whole cell lysates, but cyclosporine A (CsA) fails to show such an inhibition effect. Notably, Pifithrin-α is able to block the GOX-induced Bcl-2 protein reduction. Similarly, it is Pifithrin-α rather than CsA that able to prevent the Bax increasing in whole cell lysates[1]. Pifithrin-α inhibits p53-dependent apoptosis through an undetermined mechanism. Pifithrin-α also acts as an aryl hydrocarbon receptor (AhR) agonist and. Pifithrin-α is a potent AhR agonist as determined by its ability to bind the AhR, induce formation of its DNA binding complex, activate reporter activity, and up-regulate the classic AhR target gene CYP1A1[2].

[In Vivo]

When the experiment is performed with Pifthirin-α (PFT-α) hydrobromide, a pharmacological p53 inhibitor, the percentage of annexin V-positive Foxe3-/- SMCs decreases to WT levels. Pifithrin-α (2.2 mg/kg, i.p.) significantly reduces the incidence of aortic rupture and intramural hematomas in Foxe3-/- mice that underwent transverse aortic constriction (TAC) (50% to 17%, P<0.05). After Pifthirin-α treatment, the mean diameter of the ascending aorta and the percentage of TUNEL-positive cells in the aortic media are also normalized to WT levels in surviving Foxe3-/- animals (P<0.05)[3].

[Kinase Assay]

The ligand binding competition assays are performed. Cytosolic cell extracts from Hepa-1 cells are generated by the resuspension of the cell pellets in HEDG buffer [25 mM Hepes, 1 mM EDTA, 1 mM dithiothreitol, and 10% (v/v) glycerol, pH 7.5] containing 0.4 mM leupeptin, 4 mg/mL aprotinin, and 0.3 mM phenylmethylsulfonyl fluoride, homogenization, and centrifugation at 100,000 g for 45 min. Aliquots of the supernatant (120 μg) are incubated at room temperature for 2 h with the indicated concentrations of Pifithrin-α in the presence of 3 nM [3H]TCDD in HEDG buffer. After incubation on ice with hydroxyapatite for 30 min, HEDG buffer with 0.5% Tween 80 is added. The samples are centrifuged, washed twice, resuspended in 0.2 mL of scintillation fluid, and subjected to scintillation counting. Nonspecific binding is determined using a 150-fold molar excess of TCDF and subtracted from the total binding to obtain the specific binding. The specific binding is reported relative to [3H]TCDD alone[2].

[Cell Assay]

The human hepatoma cell lines HepG2 (p53++) are cultured in RMPI 1640 medium with 10% fetal bovine serum (FBS), and 1% penicillin/streptomycin at 37°C in an atmosphere containing 5% CO2. Cells are exposed to GOX (0-5 0U) for 0-8 hours with or without Pifithrin-α (20 μM/L), Pifithrin-μ (5 μM/L), CsA (10 μM/L), Sanglifehrin A (20 μM/L) and NAC (5 mM/L) for 1 hour, respectively. After treatment, cells are collected and processed for further experiments[1].

[Animal admin]

Mice[3] The Foxe3-null (Foxe3-/-) mice are used. To investigate the role of p53 in Foxe3-related apoptosis, Pifithrin-α is administered by i.p. injection at a dosage of 2.2 mg/kg, then dissolved in PBS 1 hour before TAC and then every 48 hours. Animals are euthanized 2 weeks after the surgery, and the ascending aortic tissues are harvested for either RNA, total protein, histomorphometric analysis, or TUNEL assay.

[References]

[1]. Yu W, et al. Cyclosporine A Suppressed Glucose Oxidase Induced P53 Mitochondrial Translocation and Hepatic Cell Apoptosis through Blocking Mitochondrial Permeability Transition. Int J Biol Sci. 2016 Jan 1;12(2):198-209.

[2]. Hoagland MS, et al. The p53 Inhibitor Pifithrin-α Is a Potent Agonist of the Aryl Hydrocarbon Receptor. J Pharmacol Exp Ther. 2005 Aug;314(2):603-10.

[3]. Kuang SQ, et al. FOXE3 mutations predispose to thoracic aortic aneurysms and dissections. J Clin Invest. 2016 Mar 1;126(3):948-61.

[Related Small Molecules]

Chemical & Physical Properties

[ Density]:
1.28g/cm3

[ Boiling Point ]:
456.8ºC at 760 mmHg

[ Melting Point ]:
192.1-192.5ºC(lit.)

[ Molecular Formula ]:
C₁₆H₁₉BrN₂OS

[ Molecular Weight ]:
367.304

[ Flash Point ]:
230.1ºC

[ Exact Mass ]:
366.040131

[ PSA ]:
74.09000

[ LogP ]:
4.15700

[ Appearance of Characters ]:
powder

[ Index of Refraction ]:
1.666

[ Storage condition ]:
−20°C

[ Water Solubility ]:
DMSO: 20 mg/mL

Safety Information

[ Personal Protective Equipment ]:
Eyeshields;Gloves;type N95 (US);type P1 (EN143) respirator filter

[ RIDADR ]:
NONH for all modes of transport

[ WGK Germany ]:
3

Synthetic Route

Click to get detail synthetic route

Precursor & DownStream

Precursor

DownStream

Articles

A chemical inhibitor of p53 that protects mice from the side effects of cancer therapy.

Science 285 , 1733-1737, (1999)

Chemotherapy and radiation therapy for cancer often have severe side effects that limit their efficacy. Because these effects are in part determined by p53-mediated apoptosis, temporary suppression of...

Suppression of p53: a new approach to overcome side effects of antitumor therapy.

Biochemistry 65 , 41-48, (2000)

The p53 protein is traditionally believed to be a tumor suppressor. Activation of p53-dependent apoptosis in response to damage to cell DNA provides for the elimination of possible tumor cell precurso...

p53 protein-mediated up-regulation of MAP kinase phosphatase 3 (MKP-3) contributes to the establishment of the cellular senescent phenotype through dephosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2).

J. Biol. Chem. 290(2) , 1129-40, (2015)

Growth arrest is one of the essential features of cellular senescence. At present, the precise mechanisms responsible for the establishment of the senescence-associated arrested phenotype are still in...