β-catenin-responsive transcription (CRT; IC50 = 40.3 nM)

Apart from its impact on the TCF-β-cat response, iCRT 14 has the ability to obstruct TCF's DNA binding [1]. Although it was still less than iCRT 3, iCRT 14 (10, 25, 50 μM) efficiently and time- and dose-dependently reduced the growth of BT-549 cells [2].

In HCT116 xenografts, iCRT 14 (50 mg/kg, i.p.) dramatically decreases CycD1, tumor swelling [1].

Thermal Stability Analysis.[1]
Purified β-cat-His and TCF4-N-GST were mixed in a 1:2 molar ratio in 1× PBS at room temperature in the presence of various concentrations of iCRTs (such as iCRT-14) and 0.5× SYPRO Orange. Samples were heated in 96-well plates using a LightCycler 480 System from 20 °C to 95 °C at a ramp rate of 0.06 °C per s. Fluorescence readings were acquired at 0.1-s intervals during the heating phase. Melting temperatures were calculated by plotting negative derivates of fluorescence intensity reading against temperature. Inflection point on the negative derivative curve is considered the melting temperature (Tm).

For cell proliferation assay in each cell line, cells were treated with DMSO as the vehicle or different concentrations of each Wnt inhibitor: iCRT-3 (25, 50, 75 μM), iCRT-5 (50, 100, 200 μM), iCRT-14 (10, 25, 50 μM), IWP-4 (1, 2.5, 5 μM), and XAV-939 (5, 10 μM). For cell proliferation, migration and invasion assays in BT549 cells with SOX4 knockdown, cells were treated with DMSO or 25 μM iCRT-3. The upper chamber of CIM-plate 16 was coated with Matrigel (1:40 dilution) for cell invasion assay. In addition, cell proliferation was measured in BT-549 cells with SOX4 knockdown that were treated with 50 μM genistein for six days, and 25 μM iCRT-3 at the time of the experiment. Each sample was assayed in triplicate, and three independent experiments were performed. Cell proliferation assays were run for 48 hours, and cell migration and invasion experiments for 24 hours. Cell index value, which is used to measure the relative change in electrical impedance to represent cell morphology, adhesion or viability, was calculated for each sample by the RTCA Software Package 1.2.[2]

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Cells were seeded at 20,000 cells/well into 96-well plates. After overnight incubation, cells were treated with DMSO or each Wnt inhibitor (iCRT-3, 75 μM; iCRT-5, 200 μM; iCRT-14, 50 μM; IWP-4, 5 μM and XAV-939, 10 μM) for 48 hours. Cell viability was determined using the Cell Titer-Glo luminescent cell viability assay kit according to the manufacturer’s instructions. Luminescence was measured using FLUOstar microplate reader. All treatments were performed in triplicate, and each experiment was repeated three times[2].

[1]. An RNAi-based chemical genetic screen identifies three small-molecule inhibitors of the Wnt/wingless signaling pathway. Proc Natl Acad Sci USA. 2011 Apr 12;108(15):5954-63.

[2]. Wnt signaling blockage inhibits cell proliferation and migration, and induces apoptosis in triple-negative breast cancer cells. J Transl Med. 2013 Nov 4;11:280.

Misregulated β-catenin responsive transcription (CRT) has been implicated in the genesis of various malignancies, including colorectal carcinomas, and it is a key therapeutic target in combating various cancers. Despite significant effort, successful clinical implementation of CRT inhibitory therapeutics remains a challenging goal. This is, in part, because of the challenge of identifying inhibitory compounds that specifically modulate the nuclear transcriptional activity of β-catenin while not affecting its cytoskeletal function in stabilizing adherens junctions at the cell membrane. Here, we report an RNAi-based modifier screening strategy for the identification of CRT inhibitors. Our data provide support for the specificity of these inhibitory compounds in antagonizing the transcriptional function of nuclear β-catenin. We show that these inhibitors efficiently block Wnt/β-catenin-induced target genes and phenotypes in various mammalian and cancer cell lines. Importantly, these Wnt inhibitors are specifically cytotoxic to human colon tumor biopsy cultures as well as colon cancer cell lines that exhibit deregulated Wnt signaling. [1]

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Background: Triple-negative breast cancer (TNBC) is an aggressive clinical subtype of breast cancer that is characterized by the lack of estrogen receptor (ER) and progesterone receptor (PR) expression as well as human epidermal growth factor receptor 2 (HER2) overexpression. The TNBC subtype constitutes approximately 10%-20% of all breast cancers, but has no effective molecular targeted therapies. Previous meta-analysis of gene expression profiles of 587 TNBC cases from 21 studies demonstrated high expression of Wnt signaling pathway-associated genes in basal-like 2 and mesenchymal subtypes of TNBC. In this study, we investigated the potential of Wnt pathway inhibitors in effective treatment of TNBC. Methods: Activation of Wnt pathway was assessed in four TNBC cell lines (BT-549, MDA-MB-231, HCC-1143 and HCC-1937), and the ER+ cell line MCF-7 using confocal microscopy and Western blot analysis of pathway components. Effectiveness of five different Wnt pathway inhibitors (iCRT-3, iCRT-5, iCRT-14, IWP-4 and XAV-939) on cell proliferation and apoptosis were tested in vitro. The inhibitory effects of iCRT-3 on canonical Wnt signaling in TNBC was evaluated by quantitative real-time RT-PCR analysis of Axin2 and dual-luciferase reporter assays. The effects of shRNA knockdown of SOX4 in combination with iCRT-3 and/or genistein treatments on cell proliferation, migration and invasion on BT-549 cells were also evaluated. Results: Immunofluorescence staining of β-catenin in TNBC cell lines showed both nuclear and cytoplasmic localization, indicating activation of Wnt pathway in TNBC cells. iCRT-3 was the most effective compound for inhibiting proliferation and antagonizing Wnt signaling in TNBC cells. In addition, treatment with iCRT-3 resulted in increased apoptosis in vitro. Knockdown of the Wnt pathway transcription factor, SOX4 in triple negative BT-549 cells resulted in decreased cell proliferation and migration, and combination treatment of iCRT-3 with SOX4 knockdown had a synergistic effect on inhibition of cell proliferation and induction of apoptosis. Conclusions: These data suggest that targeting SOX4 and/or the Wnt pathway could have therapeutic benefit for TNBC patients.[2]

C21H17N3O2S

375.44358

375.104

C, 67.18; H, 4.56; N, 11.19; O, 8.52; S, 8.54

677331-12-3

901751-47-1(iCRT3); 18623-44-4 (iCRT5)

5967294

Light yellow to yellow solid powder

4.795

0

4

3

27

617

0

CC1=CC(=C(N1C2=CN=CC=C2)C)/C=C\3/C(=O)N(C(=O)S3)C4=CC=CC=C4

NCSHZXNGQYSKLR-XDHOZWIPSA-N

InChI=1S/C21H17N3O2S/c1-14-11-16(15(2)23(14)18-9-6-10-22-13-18)12-19-20(25)24(21(26)27-19)17-7-4-3-5-8-17/h3-13H,1-2H3/b19-12+

5-[[2,5-dimethyl-1-(3-pyridinyl)-1H-pyrrol-3-yl]methylene]-3-phenyl-2,4-thiazolidinedione

iCRT14; iCRT-14; 677331-12-3; iCRT-14; iCRT14; (5Z)-5-[(2,5-dimethyl-1-pyridin-3-ylpyrrol-3-yl)methylidene]-3-phenyl-1,3-thiazolidine-2,4-dione; CHEMBL3589010; (5Z)-5-{[2,5-Dimethyl-1-(3-pyridinyl)-1H-pyrrol-3-yl]methylene}-3-phenyl-1,3-thiazolidine-2,4-dione; (5Z)-5-{[2,5-dimethyl-1-(pyridin-3-yl)-1H-pyrrol-3-yl]methylidene}-3-phenyl-1,3-thiazolidine-2,4-dione; iCRT 14

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : ≥ 29 mg/mL (~77.24 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (6.66 mM) (saturation unknown) in 10% DMSO + 40% PEG300 +5% Tween-80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 + to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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 (Please use freshly prepared in vivo formulations for optimal results.)