Lexibulin (CYT997)

Catalog No.S2195 Batch:S219501

Print

Technical Data

Formula

C24H30N6O2
Molecular Weight 434.53 CAS No. 917111-44-5
Solubility (25°C)* In vitro DMSO 86 mg/mL (197.91 mM)
Ethanol 20 mg/mL (46.02 mM)
Water Insoluble
* <1 mg/ml means slightly soluble or insoluble.
* Please note that Selleck tests the solubility of all compounds in-house, and the actual solubility may differ slightly from published values. This is normal and is due to slight batch-to-batch variations.
* Room temperature shipping (Stability testing shows this product can be shipped without any cooling measures.)

Preparing Stock Solutions

Biological Activity

Description Lexibulin (CYT997, SRI-32007) is a potent microtubule polymerization inhibitor with IC50 of 10-100 nM in cancer cell lines. Phase 2.
Targets
Microtubules (cancer cell lines) [1]
10 nM-100 nM
In vitro CYT997 (1 μM) treatment for 24 hours in A549 cells induces rapid reorganization of microtubules including the destruction of the existing microtubule network and accumulation of tubulin in plaques within the cytoplasm of some cells, leading to significant cell morphology alterations including the loss of adhesion and cell rounding. CYT997 displays potent cytotoxic activity against a range of 16 cancer cells with IC50 ranging from 9 nM for HepG2 to 101 nM for KHOS/NP. Especially, CYT997 exhibits potent activity against HCT15 cells, known to possess the multidrug resistance mechanism Pgp (MDR+), with IC50 of 52 nM. Through inhibition of microtubule polymerization, CYT997 blocks the cell cycle at the G2-M boundary, and induces an increase in phosphorylated Bcl-2 and increased expression of cyclin B1, as well as caspase-3 activation and the generation of poly (ADP-ribose) polymerase. CYT997 treatment causes a rapid and reversible increase in the permeability of HUVEC monolayers with IC50 of ~80 nM at 1 hour of exposure. [1] Consistent with the disruption of cellular tubulin, CYT997 potently inhibits proliferation, induces cell cycle arrest and most importantly apoptosis of both human myeloma cell lines (HMCLs) and primary MM cells. [2]
In vivo The half-life of CYT997 for oral administration (2.5 hours) to rats is slightly longer than that for intravenous administration (1.5 hours), with the absolute oral bioavailability being 50% to 70%. Oral administration of CYT997 induces dose-dependent inhibition of tumor growth of PC3 xenografts in mice, more potently compared with paclitaxel. CYT997 is also effective in an orthotopic syngeneic model using the mouse breast cancer 4T1 cells, which are some refractory to Paclitaxel treatment. A single dose of CYT997 (7.5 mg/kg, i.p.) reduces tumor blood flow significantly at 6 hours in liver metastases, to a similar extent as the positive control CA4P dosed at 100 mg/kg. [1] CYT997 treatment (15 mg/kg/day) significantly prolongs the survival in a murine model of aggressive systemic myelomatosis. [2]

Protocol (from reference)

Kinase Assay:[1]
  • Turbidimetric assay for tubulin polymerization

    The effect of CYT997 on microtubule polymerization is determined using conventional turbidimetric assay using bovine neuronal tubulin in which the assembly of microtubules is monitored by an increase in absorbance at 340 nm. Increasing concentrations of CYT997 is added to 100 μL of tubulin/GTP/glycerol. Turbidimetric assays of microtubule assembly is done by incubating bovine microtubule protein in cuvettes at 37 °C in a thermostatically controlled spectrophotometer measuring the change in absorbance at 340 nm over time in PEM buffer [80 nM PIPES (pH 6.9), 2 mM MgCl2, 0.5 mM EGTA, and 5% glycerol].
Cell Assay:[1]
  • Cell lines

    DU145, A549, Ramos, KHOS/NP, A375, HCT-15, HT1376, BT-20, A431, PA-1, U937, HepG2, TF-1, Baf3/TelJAK2, PC3, and K562

  • Concentrations

    Dissolved in DMSO, final concentrations ~1 μM

  • Incubation Time

    ~72 hours

  • Method

    Cells are exposed to various concentrations of CYT997 for ~72 hours. Cell proliferation is assessed with either the Alamar blue or MTT assays. For MTT assays, 5 mg/mL of MTT is added to all wells, plates are incubated for 6 hours at 37 °C, and then lysis buffer is added (10% SDS in 0.01 N HCl) and absorbance is measured at 620 nm in a BMG Technologies Lumistar or Polarstar plate reader. For Alamar blue assays, Alamar blue (10 μL/well) is added to each well and the plates are incubated at 37 °C for 4 hours. The fluorescence is then measured using a fluorescence plate reader with an excitation filter at 544 nm and an emission filter at 590 nm. For cell cycle analysis, cells are fixed and permeabilized with 70% ethanol in PBS and incubated at 4 °C overnight. RNase-treated samples (10 μg RNase/mL for 20 minutes at 37 °C) are stained with propidium iodide (5 μg/mL) at 4 °C for a minimum of 10 minutes. Cell cycle variables are determined by fluorescence-activated cell sorting (FACS) analysis using a Beckman-Coulter Quanta SC MPL system and analyzed using CXP Software. For apoptosis analysis, cells are detached and collected. Annexin staining is done using the Vybrant Apoptosis Assay Kit. Cells are stored on ice and analyzed on a Beckman Coulter Quanta MPL within 1 hour of preparation. Annexin V–positive cells are determined using two-channel analysis.
Animal Study:[1]
  • Animal Models

    Male nude mice inoculated s.c. with PC3 cells, and female BALB/c mice inoculated with 4T1 cells

  • Dosages

    ~30 mg/kg/day

  • Administration

    Oral gavage thrice a day

Customer Product Validation

Data from [Exp Ther Med, 2013, 6(2), 299-304]

Data from [Exp Ther Med, 2013, 6(2), 299-304]

Data from [Exp Ther Med, 2013, 6(2), 299-304]

Data from [Exp Ther Med, 2013, 6(2), 299-304]

Selleck's Lexibulin (CYT997) has been cited by 8 publications

A modular master regulator landscape controls cancer transcriptional identity [ Cell, 2021, 184(2):334-351.e20] PubMed: 33434495
HBV Core Promoter Inhibition by Tubulin Polymerization Inhibitor (SRI-32007) [ Adv Virol, 2020, 2020:8844061] PubMed: 33110426
CYT997(Lexibulin) induces apoptosis and autophagy through the activation of mutually reinforced ER stress and ROS in osteosarcoma [ J Exp Clin Cancer Res, 2019, 38(1):44] PubMed: 30704503
Intracellular reduction in ATP levels contributes to CYT997-induced suppression of metastasis of head and neck squamous carcinoma. [ J Cell Mol Med, 2019, 23(2):1174-1182] PubMed: 30450674
Survival of midbrain dopamine neurons depends on the Bcl2 factor Mcl1 [ Cell Death Discov, 2018, 4:107] PubMed: 30479840
Augmentation of the anticancer activity of CYT997 in human prostate cancer by inhibiting Src activity. [ J Hematol Oncol, 2017, 10(1):118] PubMed: 28606127
Structures of a diverse set of colchicine binding site inhibitors in complex with tubulin provide a rationale for drug discovery. [ FEBS J, 2016, 283(1):102-11] PubMed: 26462166
The microtubule depolymerizing agent CYT997 effectively kills acute myeloid leukemia cells via activation of caspases and inhibition of PI3K/Akt/mTOR pathway proteins. [XIAOHUI CHEN, et al. Exp Ther Med, 2013, 6(2):299-304] PubMed: 24137178

RETURN POLICY
Selleck Chemical’s Unconditional Return Policy ensures a smooth online shopping experience for our customers. If you are in any way unsatisfied with your purchase, you may return any item(s) within 7 days of receiving it. In the event of product quality issues, either protocol related or product related problems, you may return any item(s) within 365 days from the original purchase date. Please follow the instructions below when returning products.

SHIPPING AND STORAGE
Selleck products are transported at room temperature. If you receive the product at room temperature, please rest assured, the Selleck Quality Inspection Department has conducted experiments to verify that the normal temperature placement of one month will not affect the biological activity of powder products. After collecting, please store the product according to the requirements described in the datasheet. Most Selleck products are stable under the recommended conditions.

NOT FOR HUMAN, VETERINARY DIAGNOSTIC OR THERAPEUTIC USE.