APTO253 free base

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MedKoo CAT#: 205517

CAS#: 916151-99-0 (Free base)

Description: APTO-253 is a small molecule inhibitor of human metal-regulatory transcription factor 1 (MTF-1) with potential antitumor activity. MTF-1 inhibitor LOR-253 inhibits MTF-1 activity and thereby induces the expression of MTF-1 dependent tumor suppressor factor Kruppel like factor 4 (KLF4). This subsequently leads to the downregulation of cyclin D1, blocking cell cycle progression and proliferation. This agent also causes decreased expression of genes involved in tumor hypoxia and angiogenesis.

Chemical Structure

APTO253 free base
CAS# 916151-99-0 (Free base)

Theoretical Analysis

MedKoo Cat#: 205517
Name: APTO253 free base
CAS#: 916151-99-0 (Free base)
Chemical Formula: C22H14FN5
Exact Mass: 367.12332
Molecular Weight: 367.38
Elemental Analysis: C, 71.92; H, 3.84; F, 5.17; N, 19.06

Price and Availability

Size Price Availability Quantity
5.0mg USD 280.0 2 Weeks
10.0mg USD 435.0 2 Weeks
50.0mg USD 910.0 2 Weeks
100.0mg USD 1350.0 2 Weeks
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Related CAS #: 1691221-67-6 (HCl)   916151-99-0 (Free base)   1422731-37-0 (APTO-253 isomer HCl)   1422826-80-9 (APTO-253 isomer free base)    

Synonym: APTO253; APTO 253; APTO-253; LOR253; LOR-253; LOR 253; LT253.

IUPAC/Chemical Name: 2-(5-fluoro-2-methyl-1H-indol-3-yl)-1H-imidazo[4,5-f][1,10]phenanthroline


InChi Code: InChI=1S/C22H14FN5/c1-11-17(15-10-12(23)6-7-16(15)26-11)22-27-20-13-4-2-8-24-18(13)19-14(21(20)28-22)5-3-9-25-19/h2-10,26H,1H3,(H,27,28)

SMILES Code: CC(N1)=C(C2=NC3=C4C=CC=NC4=C5N=CC=CC5=C3N2)C6=C1C=CC(F)=C6

Appearance: Solid powder

Purity: >98% (or refer to the Certificate of Analysis)

Shipping Condition: Shipped under ambient temperature as non-hazardous chemical. This product is stable enough for a few weeks during ordinary shipping and time spent in Customs.

Storage Condition: Dry, dark and at 0 - 4 C for short term (days to weeks) or -20 C for long term (months to years).

Solubility: Soluble in DMSO, not in water

Shelf Life: >2 years if stored properly

Drug Formulation: This drug may be formulated in DMSO

Stock Solution Storage: 0 - 4 C for short term (days to weeks), or -20 C for long term (months).

HS Tariff Code: 2934.99.9001

Preparing Stock Solutions

The following data is based on the product molecular weight 367.38 Batch specific molecular weights may vary from batch to batch due to the degree of hydration, which will affect the solvent volumes required to prepare stock solutions.

Recalculate based on batch purity %
Concentration / Solvent Volume / Mass 1 mg 5 mg 10 mg
1 mM 1.15 mL 5.76 mL 11.51 mL
5 mM 0.23 mL 1.15 mL 2.3 mL
10 mM 0.12 mL 0.58 mL 1.15 mL
50 mM 0.02 mL 0.12 mL 0.23 mL

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1: Local A, Zhang H, Benbatoul KD, Folger P, Sheng X, Tsai CY, Howell SB, Rice WG. APTO-253 Stabilizes G-quadruplex DNA, Inhibits MYC Expression, and Induces DNA Damage in Acute Myeloid Leukemia Cells. Mol Cancer Ther. 2018 Jun;17(6):1177-1186. doi: 10.1158/1535-7163.MCT-17-1209. Epub 2018 Apr 6. PubMed PMID: 29626127.

2: Tsai CY, Sun S, Zhang H, Local A, Su Y, Gross LA, Rice WG, Howell SB. APTO-253 Is a New Addition to the Repertoire of Drugs that Can Exploit DNA BRCA1/2 Deficiency. Mol Cancer Ther. 2018 Jun;17(6):1167-1176. doi: 10.1158/1535-7163.MCT-17-0834. Epub 2018 Apr 6. PubMed PMID: 29626126.

3: Wang B, Shen A, Ouyang X, Zhao G, Du Z, Huo W, Zhang T, Wang Y, Yang C, Dong P, Watari H, Pfeffer LM, Yue J. KLF4 expression enhances the efficacy of chemotherapy drugs in ovarian cancer cells. Biochem Biophys Res Commun. 2017 Mar 11;484(3):486-492. doi: 10.1016/j.bbrc.2017.01.062. Epub 2017 Jan 18. PubMed PMID: 28108288.

4: Cercek A, Wheler J, Murray PE, Zhou S, Saltz L. Phase 1 study of APTO-253 HCl, an inducer of KLF4, in patients with advanced or metastatic solid tumors. Invest New Drugs. 2015 Oct;33(5):1086-92. doi: 10.1007/s10637-015-0273-z. Epub 2015 Aug 14. PubMed PMID: 26268924.

Additional Information

LOR-253 (formerly LT-253) is currently being developed by Lorus Therapeutics.  LOR-253 is a first-in-class inhibitor of the Metal Transcription Factor-1 (MTF-1) with a novel mode of action. This consists of the induction of the tumor suppresor factor Krüppel like factor 4 (KLF4) leading to the downregulation of cyclin D1, an important regulator of cell cycle progression and cell proliferation, and decreased expression of genes involved in tumor hypoxia (low oxygen content) and angiogenesis. Increased angiogenesis and alterations in the cyclin D1 regulatory pathway have been linked to the development of cancer.  LOR-253 has selective and potent antitumor activity in a variety of human cancers, including colon and non-small cell lung cancer, and has demonstrated an excellent therapeutic index in experimental models. We have successfully completed GLP, IND-enabling toxicology studies for LOR-253, which included maximum tolerated dose (MTD) studies and repeat-dose toxicity studies in rodents and nonrodents. A Phase I dose escalation clinical trial to establish MTD and expansion at the MTD to evaluate intratumoral correlates of activity is expected to start by Q2 2010. (source: http://www.lorusthera.com/products-technology/small-molecule-platform.php).