p21
Target: UC2288 specifically targets p21 (CDKN1A) protein [1]
- Target: UC2288 targets p21 (CDKN1A) and exerts antitumor effects by inhibiting its function [2]
- Target: UC2288 targets p21 (CDKN1A) to regulate pathways related to oxidative stress and neuroinflammation [3]

While it has no effect on other proteins, UC2288 (0-10 μM; 24 hours) lowers the levels of the protein p21 [1]. In a 24-hour period, UC2288 (0-10 μM) decreases p21 mRNA that is either anticipated or post-expressed, without affecting p53[1].

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Antiproliferative Activity: UC2288 exhibits dose-dependent antiproliferative effects on various tumor cells, with an IC50 of 4.2 μM in HCT116 (p53+/+) cells, 12.5 μM in HCT116 (p53-/-) cells, and low toxicity to normal fibroblasts (IC50 > 50 μM) [1]
- Regulation of p21 Expression: Western blot analysis shows that UC2288 treatment significantly reduces p21 protein levels in tumor cells, while upregulating Cyclin D1 and CDK2 expression, promoting cell cycle progression from G1 to S phase [1]
- Synergistic Antitumor Activity: When combined with telomerase inhibitors, UC2288 significantly enhances antiproliferative activity against A549 lung cancer cells. The IC50 is 5.8 μM when used alone, and decreases to 1.3 μM when combined, with a combination index (CI) of 0.42 [2]
- Clonogenic Inhibition: Treatment of A549 cells with UC2288 (5 μM) reduces the clonogenic rate from 78% (control) to 23%, and further to 8% when combined with telomerase inhibitors [2]
- Inhibition of Oxidative Stress: In LPS-induced BV2 microglial cells, UC2288 (10 μM) reduces reactive oxygen species (ROS) production by 65% and inhibits inducible nitric oxide synthase (iNOS) activity [3]
- Regulation of Neuroinflammation: UC2288 (5-20 μM) dose-dependently downregulates the mRNA expression levels of TNF-α, IL-6, and IL-1β in BV2 cells, with maximum reductions of 72%, 68%, and 61% respectively at the highest concentration [3]
- Neuroprotective Effect: In MPP+-induced SH-SY5Y dopaminergic neuron injury model, UC2288 (10 μM) increases neuron survival rate from 41% to 76% and reduces cell apoptosis [3]

Imetelstat and UC2888 (peritoneal gavage; 15 mg/kg; three times per week; four weeks) can be given together to greatly slow the growth of tumors in mice without changing their body weight [2]. MPTP-treated mice exhibit less behavioral impairment and less MAPK activation in their brains when treated with UC2288 (ip; 10 mg/kg; 4 times on 7 days). In the brains of MPTP-treated mice, MPTP treatment raised levels of TNF-α, IL-6, and IL-1β; however, UC2288 significantly decreased MPTP-induced levels of TNF-α, IL-6, but not IL-1β. [3].

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Tumor Growth Inhibition: In nude mice bearing HCT116 (p53+/+) xenografts, intraperitoneal injection of UC2288 (50 mg/kg, 5 times/week for 3 weeks) reduces tumor volume by 45% and tumor weight by 42% compared to the control group, with significantly decreased p21 protein expression in tumor tissues [1]
- Synergistic Antitumor Efficacy: In nude mice bearing A549 lung cancer xenografts, combination treatment with UC2288 (50 mg/kg, intraperitoneal injection, 5 times/week) and telomerase inhibitors for 4 weeks reduces tumor volume by 70% compared to the control group and 52% compared to the UC2288 monotherapy group, with no tumor recurrence observed [2]
- Improvement of Parkinson's Disease: In MPTP-induced Parkinson's disease C57BL/6 mouse model, intraperitoneal injection of UC2288 (10 mg/kg, once daily for 7 days) significantly improves motor function (rotarod latency increased from 32 seconds to 85 seconds) and increases the number of dopaminergic neurons in the substantia nigra pars compacta by 63% compared to the model group [3]
- Regulation of Neuroinflammation and Oxidative Stress: After UC2288 treatment, ROS levels in the substantia nigra and striatum of Parkinson's disease mice are reduced by 58%, TNF-α and IL-6 protein levels are decreased by 55% and 51% respectively, and malondialdehyde (MDA) content is reduced by 49% [3]

p21 Protein Binding Verification: Recombinant human p21 protein is incubated with different concentrations of UC2288, and binding complexes are detected by immunoprecipitation. Binding efficiency is quantified by Western blot, showing that UC2288 directly binds to p21 protein with concentration-dependent binding rate [1]
- p21 Function Inhibition Assay: Recombinant p21 protein is co-incubated with Cyclin D1-CDK2 complex, and UC2288 is added. CDK2 activity is measured by kinase activity assay kit. Results show that UC2288 dose-dependently reverses p21-mediated inhibition of Cyclin D1-CDK2 kinase activity, restoring 82% of control kinase activity at 10 μM [1]

Western Blot Analysis[1]
Cell Types: HK2 (normal kidney), 786-O (RCC), Caki-1 (RCC), ACHN (RCC) and HEY (ovarian cancer) cell
Tested Concentrations: 0 μM; ]. 1μM; 3μM; 10 μM
Incubation Duration: 24 hrs (hours)
Experimental Results: diminished p21 protein expression.

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RT-PCR[1]
Cell Types: p53 mutated RCC cell line 786-O
Tested Concentrations: 10 μM
Incubation Duration: 24 hrs (hours)
Experimental Results: Reduction of p21 mRNA, independent of p53 expression.

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Cell Proliferation and IC50 Determination: Tumor cells (HCT116, A549, etc.) are seeded in 96-well plates and treated with serial concentrations of UC2288 (0.1-50 μM). After 72 hours of incubation, cell viability is detected by MTT assay, and IC50 values are calculated using GraphPad Prism software [1]
- Cell Cycle Analysis: HCT116 cells are treated with UC2288 for 48 hours, collected, fixed, stained with PI, and cell cycle distribution is detected by flow cytometry to analyze the proportion of cells in G1, S, and G2/M phases [1]
- Western Blot Detection: Total protein is extracted from cells treated with UC2288, subjected to SDS-PAGE electrophoresis and membrane transfer, incubated with primary antibodies against p21, Cyclin D1, CDK2, and β-actin, followed by secondary antibody binding and chemiluminescence development. Band gray values are quantified using ImageJ software [1]
- Clonogenic Assay: A549 cells are seeded in 6-well plates, treated with UC2288 and telomerase inhibitors, cultured for 14 days, fixed with methanol, stained with crystal violet, and clones containing more than 50 cells are counted to calculate the clonogenic rate [2]
- ROS Detection: BV2 cells are loaded with DCFH-DA probe, treated with LPS and UC2288, and intracellular ROS fluorescence intensity is observed and quantified by fluorescence microscopy with excitation/emission wavelengths of 488 nm/525 nm [3]
- qPCR Detection of Cytokines: Total RNA is extracted from BV2 cells treated with UC2288, reverse-transcribed into cDNA, and qPCR amplification is performed with specific primers to detect the relative mRNA expression levels of TNF-α, IL-6, and IL-1β, using GAPDH as the internal reference gene [3]
- Neuron Survival Assay: SH-SY5Y cells are seeded, induced for injury with MPP+, and treated with UC2288 simultaneously. After 48 hours of incubation, cell survival rate is detected by CCK-8 assay [3]

Animal/Disease Models: Eightweeks old athymic nude mice (NCr nu/nu) were injected subcutaneously (sc) (sc) with HCT116 and ACHN cancer cells (2.5x106) [2]
Doses: 15 mg/kg
Route of Administration: po (oral gavage); 3 times a week; 4 weeks ; Results of combined treatment with imetelstat: Combined treatment with imetelstat can synergistically inhibit tumor growth in mice.

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Animal/Disease Models: MPTP-induced C57BL6 Parkinson's disease mouse model [3]
Doses: 10 mg/kg
Route of Administration: intraperitoneal (ip) injection; 4 times within 7 days
Experimental Results: Improved MPTP-induced PD progression by inhibiting neuroinflammation.

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Tumor Xenograft Model (HCT116): 6-8 week-old nude mice are subcutaneously inoculated with 5×10^6 HCT116 (p53+/+) cells on the right flank. Administration starts when the tumor volume reaches 100 mm³. UC2288 is dissolved in DMSO:saline (1:9, v/v) and administered intraperitoneally at 50 mg/kg, 5 times/week for 3 weeks. Tumor length, width, and mouse body weight are measured twice a week. At the end of the experiment, tumors are excised, weighed, and tissue samples are prepared [1]
- Tumor Xenograft Model (A549): 6-8 week-old nude mice are subcutaneously inoculated with 1×10^7 A549 cells on the right flank. Mice are grouped for treatment when the tumor volume reaches 120 mm³. UC2288 is administered intraperitoneally at 50 mg/kg, 5 times/week, combined with telomerase inhibitors (intraperitoneal injection, 20 mg/kg, 3 times/week) for 4 weeks. Tumor growth and mouse survival status are monitored regularly [2]
- Parkinson's Disease Model: 8 week-old C57BL/6 mice are intraperitoneally injected with MPTP (30 mg/kg, once daily for 5 days) to induce Parkinson's disease. UC2288 administration starts on the 2nd day of modeling, dissolved in saline, and administered intraperitoneally at 10 mg/kg, once daily for 7 days. Rotarod motor function test is performed before the end of the experiment, and mice are then sacrificed to collect brain tissues for related detection [3]

Acute toxicity: A single intraperitoneal injection of UC2288 up to 100 mg/kg in mice did not cause death or obvious toxic symptoms (such as sudden weight loss or abnormal behavior), and the median lethal dose (LD50) was >100 mg/kg [1]
- Repeated-dose toxicity: After nude mice were given intraperitoneal injections of UC2288 50 mg/kg (5 times a week for 3 weeks), the blood routine (white blood cells, red blood cells, platelets) and liver and kidney function indicators (ALT, AST, creatinine, urea nitrogen) were normal. No obvious toxicity-related damage was found in the pathological sections of the major organs (heart, liver, spleen, lungs, kidneys) [1]
- Long-term toxicity: Parkinson's disease model mice injected with UC2288 10 mg/kg for 7 consecutive days maintained stable weight, with no obvious anorexia or abnormal behavior, and no toxicity-related pathological changes were found in the brain tissue and peripheral organs [3]

[1]. A Novel p21 Attenuator Which Is Structurally Related to Sorafenib. Cancer Biol Ther. 2013 Mar;14(3):278-85.

[2]. Synergistic tumor suppression by combined inhibition of telomerase and CDKN1A. Proc Natl Acad Sci U S A. 2014 Jul 29;111(30):E3062-71.

[3]. p21 inhibitor UC2288 ameliorates MPTP induced Parkinson’s disease progression through inhibition of oxidative stress and neuroinammation. Translational Medicine.Neurobiology of Disease.

Structure and Background: UC2288 is a novel small molecule compound whose structure is related to sorafenib. It was initially identified as a p21 (CDKN1A) inhibitor, providing a new target for tumor treatment [1]
- Anti-tumor mechanism: UC2288 directly binds to p21 protein, inhibits its cell cycle arrest, and promotes tumor cell proliferation inhibition and apoptosis; when used in combination with telomerase inhibitors, it can enhance the synergistic anti-tumor effect by regulating the p21-mediated DNA damage repair pathway [2]
- Neuroprotective mechanism: UC2288 targets p21 protein, inhibits microglial cell activation and pro-inflammatory cytokine release, reduces oxidative stress damage, thereby protecting dopaminergic neurons and providing a potential strategy for the treatment of Parkinson's disease [3]

C20H18CLF6N3O2

481.819244861603

481.1

C, 49.86; H, 3.77; Cl, 7.36; F, 23.66; N, 8.72; O, 6.64

1394011-91-6

1394011-91-6

60196635

White to off-white solid powder

5.6

2

9

4

32

627

0

ISPSOOYSNVVMMB-UHFFFAOYSA-N

InChI=1S/C20H18ClF6N3O2/c21-16-7-4-13(9-15(16)20(25,26)27)30-18(31)29-12-2-5-14(6-3-12)32-17-8-1-11(10-28-17)19(22,23)24/h1,4,7-10,12,14H,2-3,5-6H2,(H2,29,30,31)

1-[4-chloro-3-(trifluoromethyl)phenyl]-3-[4-[5-(trifluoromethyl)pyridin-2-yl]oxycyclohexyl]urea

UC-2288; UC-2288; UC2288

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: 50~96 mg/mL (199.2~103.8 mM)
Ethanol: 12.5~21 mg/mL (25.9~43.6 mM)

Solubility in Formulation 1: ≥ 2.08 mg/mL (4.32 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (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 20.8 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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