Cat. No.: HY-50855

Silmitasertib

(Synonyms: CX-4945)

59 Cited Publications

Customer Review

Based on 59 publication(s) in Google Scholar

Silmitasertib (CX-4945) is an orally bioavailable, highly selective and potent CK2 inhibitor, with IC₅₀ values of 1 nM against CK2α and CK2α'.

For research use only. We do not sell to patients.

Purity: 99.81%
CAS No.: 1009820-21-6
Formula: C₁₉H₁₂ClN₃O₂
Molecular Weight:349.77

Storage:

Powder -20°C, 3 years , 4°C, 2 years ; In solvent -80°C, 2 years , -20°C, 1 year

Silmitasertib Chemical Structure

CAS No.: 1009820-21-6

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Fluorescent Dye

Strong Fluorescence Signal / Multi-Disciplinary Applications / High Fluorescence Specificity

Biological Activity
- Description
- IC₅₀ & Target
- Cellular Effect
- In Vitro
- In Vivo
- Clinical Trial
Chemical Information
Publications (59)
Solvent & Solubility
- In Vitro
- In Vivo
Protocol
Purity & Documentation
References
Help & FAQs
Classifications
Bioz

Biological Activity

Description

Silmitasertib (CX-4945) is an orally bioavailable, highly selective and potent CK2 inhibitor, with IC₅₀ values of 1 nM against CK2α and CK2α'.

IC₅₀ & Target^[1]

CK2α

1 nM (IC₅₀)

CK2α'

1 nM (IC₅₀)

All Casein Kinase Isoforms :

Cellular Effect

Cell Line	Type	Value	Description	References
786-0	EC₅₀	1 μM Compound: CX-4945	Inhibition of CK2 in human 786-0 cells assessed as decrease in alpha-catenin phosphorylation at Ser641 after 24 hrs by Western blot analysis Inhibition of CK2 in human 786-0 cells assessed as decrease in alpha-catenin phosphorylation at Ser641 after 24 hrs by Western blot analysis	[PMID: 30689946]
786-0	EC₅₀	5.3 μM Compound: CX-4945	Inhibition of CK2 in human 786-0 cells assessed as reduction in STAT3 phosphorylation at Y705 after 24 hrs by Western blot analysis Inhibition of CK2 in human 786-0 cells assessed as reduction in STAT3 phosphorylation at Y705 after 24 hrs by Western blot analysis	[PMID: 30689946]
786-0	IC₅₀	1 μM Compound: CX-4945	Inhibition of CK2 in human 786-0 cells assessed as decrease in Akt1 phosphorylation at Ser129 after 24 hrs by Western blot analysis Inhibition of CK2 in human 786-0 cells assessed as decrease in Akt1 phosphorylation at Ser129 after 24 hrs by Western blot analysis	[PMID: 30689946]
A-375	IC₅₀	3.9 μM Compound: 25n	Antiproliferative activity against human A375 cells after 4 days by alamar blue assay Antiproliferative activity against human A375 cells after 4 days by alamar blue assay	[PMID: 21174434]
A549	CC₅₀	9.9 μM Compound: CX-4945	Cytotoxicity against human A549 cells after 72 hrs by MTS assay Cytotoxicity against human A549 cells after 72 hrs by MTS assay	[PMID: 26850376]
A549	IC₅₀	11.6 μM Compound: CX-4945	Antiproliferative activity against human A549 cells incubated for 96 hrs by resazurin assay Antiproliferative activity against human A549 cells incubated for 96 hrs by resazurin assay	[PMID: 32435375]
A549	IC₅₀	3 μM Compound: 25n	Antiproliferative activity against human A549 cells after 4 days by alamar blue assay Antiproliferative activity against human A549 cells after 4 days by alamar blue assay	[PMID: 21174434]
A549	IC₅₀	8.2 μM Compound: 31, CX-4945	Antiproliferative activity against human A549 cells after 72 hrs by MTS assay Antiproliferative activity against human A549 cells after 72 hrs by MTS assay	[PMID: 22339433]
BXPC-3	IC₅₀	4.4 μM Compound: 25n	Antiproliferative activity against human BxPC3 cells after 4 days by alamar blue assay Antiproliferative activity against human BxPC3 cells after 4 days by alamar blue assay	[PMID: 21174434]
HCT-116	GI₅₀	4.8 μM Compound: CX4945	Growth inhibition of human HCT116 cells measured after 72 hrs by sulforhodamine B assay Growth inhibition of human HCT116 cells measured after 72 hrs by sulforhodamine B assay	[PMID: 36426237]
HCT-116	IC₅₀	13.21 μM Compound: CX-4945	Cytotoxicity against human HCT-116 cells assessed as reduction in cell viability incubated for 72 hrs by MTT assay Cytotoxicity against human HCT-116 cells assessed as reduction in cell viability incubated for 72 hrs by MTT assay	[PMID: 33834781]
HCT-116	IC₅₀	2.2 μM Compound: 25n	Antiproliferative activity against human HCT116 cells after 4 days by alamar blue assay Antiproliferative activity against human HCT116 cells after 4 days by alamar blue assay	[PMID: 21174434]
HCT-116	IC₅₀	5.2 μM Compound: 31, CX-4945	Antiproliferative activity against human HCT116 cells after 72 hrs by MTS assay Antiproliferative activity against human HCT116 cells after 72 hrs by MTS assay	[PMID: 22339433]
HeLa	EC₅₀	2.1 μM Compound: CX-4945	Cytotoxicity against human HeLa cells assessed as reduction in cell viability incubated for 24 hrs by resazurin-based cytotoxicity assay Cytotoxicity against human HeLa cells assessed as reduction in cell viability incubated for 24 hrs by resazurin-based cytotoxicity assay	[PMID: 34323071]
Hs-578T	IC₅₀	13.1 μM Compound: 25n	Antiproliferative activity against human Hs 578T cells after 4 days by alamar blue assay Antiproliferative activity against human Hs 578T cells after 4 days by alamar blue assay	[PMID: 21174434]
HT-22	IC₅₀	21.3 μM Compound: 9; CX-4945	Cytotoxicity against mouse HT-22 cells assessed as reduction in cell viability incubated for 48 hrs by MTS assay Cytotoxicity against mouse HT-22 cells assessed as reduction in cell viability incubated for 48 hrs by MTS assay	[PMID: 36876904]
HT-29	IC₅₀	16 μM Compound: CX-4945	Cytotoxicity against human HT-29 cells assessed as reduction in cell viability incubated for 72 hrs by MTT assay Cytotoxicity against human HT-29 cells assessed as reduction in cell viability incubated for 72 hrs by MTT assay	[PMID: 33834781]
Jurkat	CC₅₀	4.5 μM Compound: CX-4945	Antiproliferative activity against human Jurkat cells after 1 to 3 days by MTS assay Antiproliferative activity against human Jurkat cells after 1 to 3 days by MTS assay	[PMID: 23711832]
Jurkat	IC₅₀	0.1 μM Compound: 25n	Inhibition of CK2 in human Jurkat cells assessed as inhibition of [gamma33P]ATP incorporation into substrate by luminescence assay Inhibition of CK2 in human Jurkat cells assessed as inhibition of [gamma33P]ATP incorporation into substrate by luminescence assay	[PMID: 21174434]
Jurkat	IC₅₀	2.5 μM Compound: 25n	Antiproliferative activity against human Jurkat cells after 4 days by alamar blue assay Antiproliferative activity against human Jurkat cells after 4 days by alamar blue assay	[PMID: 21174434]
K562	CC₅₀	7 μM Compound: CX-4945	Antiproliferative activity against human K562 cells after 1 to 3 days by MTS assay Antiproliferative activity against human K562 cells after 1 to 3 days by MTS assay	[PMID: 23711832]
K562	IC₅₀	5.3 μM Compound: 25n	Antiproliferative activity against human K562 cells after 4 days by alamar blue assay Antiproliferative activity against human K562 cells after 4 days by alamar blue assay	[PMID: 21174434]
L02	IC₅₀	22.98 μM Compound: CX-4945	Cytotoxicity against human L02 cells assessed as reduction in cell viability incubated for 72 hrs by MTT assay Cytotoxicity against human L02 cells assessed as reduction in cell viability incubated for 72 hrs by MTT assay	[PMID: 33834781]
LNCaP	IC₅₀	4.59 μM Compound: CX4945	Cytotoxicity against human LNCAP cells assessed as cell viability after 4 days by CCK8 method Cytotoxicity against human LNCAP cells assessed as cell viability after 4 days by CCK8 method	[PMID: 22832316]
LNCaP	IC₅₀	4.7 μM Compound: 25n	Antiproliferative activity against human LNCAP cells after 4 days by alamar blue assay Antiproliferative activity against human LNCAP cells after 4 days by alamar blue assay	[PMID: 21174434]
LNCaP	IC₅₀	6.52 μM Compound: CX-4945	Antiproliferative activity against human LNCAP cells incubated for 96 hrs by resazurin assay Antiproliferative activity against human LNCAP cells incubated for 96 hrs by resazurin assay	[PMID: 32435375]
MCF7	IC₅₀	15.31 μM Compound: CX-4945	Cytotoxicity against human MCF7 cells assessed as reduction in cell viability incubated for 72 hrs by MTT assay Cytotoxicity against human MCF7 cells assessed as reduction in cell viability incubated for 72 hrs by MTT assay	[PMID: 33834781]
MCF7	IC₅₀	6.5 μM Compound: 31, CX-4945	Antiproliferative activity against human MCF7 cells after 72 hrs by MTS assay Antiproliferative activity against human MCF7 cells after 72 hrs by MTS assay	[PMID: 22339433]
MCF7	IC₅₀	8.9 μM Compound: 25n	Antiproliferative activity against human MCF7 cells after 4 days by alamar blue assay Antiproliferative activity against human MCF7 cells after 4 days by alamar blue assay	[PMID: 21174434]
MCF7	IC₅₀	9.41 μM Compound: CX-4945	Antiproliferative activity against human MCF7 cells incubated for 96 hrs by resazurin assay Antiproliferative activity against human MCF7 cells incubated for 96 hrs by resazurin assay	[PMID: 32435375]
MDA-MB-231	IC₅₀	14.25 μM Compound: 18; CX-4945	Antiproliferative activity against human MDA-MB-231 cells incubated for 24 hrs by MTT assay Antiproliferative activity against human MDA-MB-231 cells incubated for 24 hrs by MTT assay	[PMID: 34908415]
MDA-MB-231	IC₅₀	6.4 μM Compound: 25n	Antiproliferative activity against human MDA-MB-231 cells after 4 days by alamar blue assay Antiproliferative activity against human MDA-MB-231 cells after 4 days by alamar blue assay	[PMID: 21174434]
MDA-MB-231	IC₅₀	6.4 μM Compound: CX-4945	Anticancer activity against human MDA-MB-231 cells assessed as inhibition of cell viability incubated for 4 days by Alamar blue assay Anticancer activity against human MDA-MB-231 cells assessed as inhibition of cell viability incubated for 4 days by Alamar blue assay	[PMID: 37077385]
MDA-MB-468	IC₅₀	20.92 μM Compound: 18; CX-4945	Antiproliferative activity against human MDA-MB-468 cells incubated for 24 hrs by MTT assay Antiproliferative activity against human MDA-MB-468 cells incubated for 24 hrs by MTT assay	[PMID: 34908415]
MIA PaCa-2	IC₅₀	1.1 μM Compound: 25n	Antiproliferative activity against human MIAPaCa2 cells after 4 days by alamar blue assay Antiproliferative activity against human MIAPaCa2 cells after 4 days by alamar blue assay	[PMID: 21174434]
MV4-11	CC₅₀	3 μM Compound: CX-4945	Antiproliferative activity against human MV4-11 cells after 1 to 3 days by MTS assay Antiproliferative activity against human MV4-11 cells after 1 to 3 days by MTS assay	[PMID: 23711832]
NCI-H1299	IC₅₀	2.4 μM Compound: 25n	Antiproliferative activity against human H1299 cells after 4 days by alamar blue assay Antiproliferative activity against human H1299 cells after 4 days by alamar blue assay	[PMID: 21174434]
PBMC	CC₅₀	50 μM Compound: CX-4945	Cytotoxicity against human PHA-activated PBMC after 1 to 3 days by MTS assay Cytotoxicity against human PHA-activated PBMC after 1 to 3 days by MTS assay	[PMID: 23711832]
PC-3	IC₅₀	10.87 μM Compound: CX-4945	Antiproliferative activity against human PC3 cells incubated for 96 hrs by resazurin assay Antiproliferative activity against human PC3 cells incubated for 96 hrs by resazurin assay	[PMID: 32435375]
PC-3	IC₅₀	12.75 μM Compound: CX-4945	Cytotoxicity against human PC3 cells assessed as reduction in cell viability incubated for 72 hrs by MTT assay Cytotoxicity against human PC3 cells assessed as reduction in cell viability incubated for 72 hrs by MTT assay	[PMID: 33834781]
PC-3	IC₅₀	2.1 μM Compound: 25n	Antiproliferative activity against human PC3 cells after 4 days by alamar blue assay Antiproliferative activity against human PC3 cells after 4 days by alamar blue assay	[PMID: 21174434]
Sf9	IC₅₀	1.8 μM Compound: Silmitasertib	Inhibition of CDK2/cyclin E (unknown origin) expressed in Sf9 cells using histone H1 as substrate in presence of [gamma33P]ATP Inhibition of CDK2/cyclin E (unknown origin) expressed in Sf9 cells using histone H1 as substrate in presence of [gamma33P]ATP	[PMID: 24681986]
T-24	IC₅₀	12.92 μM Compound: CX-4945	Cytotoxicity against human T24 cells assessed as reduction in cell viability incubated for 72 hrs by MTT assay Cytotoxicity against human T24 cells assessed as reduction in cell viability incubated for 72 hrs by MTT assay	[PMID: 33834781]
U-937	CC₅₀	4.2 μM Compound: CX-4945	Antiproliferative activity against human U937 cells after 1 to 3 days by MTS assay Antiproliferative activity against human U937 cells after 1 to 3 days by MTS assay	[PMID: 23711832]

In Vitro

Silmitasertib (CX-4945) causes cell-cycle arrest and selectively induces apoptosis in cancer cells relative to normal cells, attenuates PI3K/Akt signalingand, and the antiproliferative activity of Silmitasertib (CX-4945) is correlated with expression levels of the CK2α catalytic subunit, Attenuation of PI3K/Akt signaling^[1]. Silmitasertib (CX-4945) with PS-341 treatment prevents leukemic cells from engaging a functional UPR in order to buffer the PS-341-mediated proteotoxic stress in ER lumen, and decreases pro-survival ER chaperon BIP/Grp78 expression^[2]. Silmitasertib (CX-4945) induces cytotoxicity and apoptosis, and exerts anti-proliferative effects in hematological tumors by downregulating CK2 expression and suppressing activation of CK2-mediated PI3K/Akt/mTOR signaling pathways^[3].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

In Vivo

Silmitasertib (CX-4945) (25 or 75 mg/kg, p.o.) is well tolerated and demonstrated robust antitumor activity with concomitant reductions of the mechanism-based biomarker phospho-p21 (T145) in murine xenograft models^[1].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

Clinical Trial

NCT Number	Sponsor	Condition	Start Date	Phase A549
NCT01329991	Plexxikon\|		2011-05	PHASE1

Chemical Information

CAS No. 1009820-21-6
Appearance Solid
Molecular Weight 349.77
Formula C₁₉H₁₂ClN₃O₂
Color Yellow to orange
SMILES

O=C(C1=CC=C2C3=C(C(NC4=CC=CC(Cl)=C4)=NC2=C1)C=CN=C3)O
Synonyms

CX-4945
Shipping

Room temperature in continental US; may vary elsewhere.

Storage

Powder	-20°C	3 years
	4°C	2 years
In solvent	-80°C	2 years
	-20°C	1 year

Publications (59)

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Journal Impact Factor

Signal Transduct Target Ther

A ribosomal gene panel predicting a novel synthetic lethality in non-BRCAness tumors. [Abstract]

2023 May 10;8(1):183. PMID: 37160887
Science

The target landscape of clinical kinase drugs. [Abstract]

2017 Dec 1;358(6367):eaan4368. PMID: 29191878
Cell

p53 safeguards chemical reprogramming of human somatic cells toward pluripotency. [Abstract]

2026 Jun 11;189(12):3541-3552.e18. PMID: 41999746
Cell Stem Cell

Highly efficient and rapid generation of human pluripotent stem cells by chemical reprogramming. [Abstract]

2023 Apr 6;30(4):450-459.e9. PMID: 36944335
Nat Cell Biol

TGF-β-induced DACT1 biomolecular condensates repress Wnt signalling to promote bone metastasis. [Abstract]

2021 Mar;23(3):257-267. PMID: 33723425

Silmitasertib purchased from MedChemExpress. Usage Cited in: Nat Cell Biol. 2021 Mar;23(3):257-267. [Abstract]

BM2-TGC cells expressing either vector or DACT1 were treated with Wnt3a +/− Silmitasertib at 5 μM for 24h.
Autophagy

TRIM21-mediated ubiquitination of SQSTM1/p62 abolishes its Ser403 phosphorylation and enhances palmitic acid cytotoxicity. [Abstract]

2025 Jan;21(1):178-190. PMID: 39172027
Nat Commun

Phosphorylation-driven epichaperome assembly is a regulator of cellular adaptability and proliferation. [Abstract]

2024 Oct 16;15(1):8912. PMID: 39414766
Nat Commun

Angiotensin-converting enzyme inhibitor promotes angiogenesis through Sp1/Sp3-mediated inhibition of notch signaling in male mice. [Abstract]

2023 Feb 9;14(1):731. PMID: 36759621
Metabolism

Body weight control via protein kinase CK2: diet-induced obesity counteracted by pharmacological targeting. [Abstract]

2024 Nov 7:162:156060. PMID: 39521118
Sci Transl Med

PP2A inhibition is a druggable MEK inhibitor resistance mechanism in KRAS-mutant lung cancer cells. [Abstract]

2018 Jul 18;10(450):eaaq1093. PMID: 30021885
Nat Plants

CK2 kinase-PRC2 signalling regulates genome-wide H3K27 trimethylation and transduces prolonged cold exposure into epigenetic cold memory in plants. [Abstract]

2025 Aug;11(8):1572-1590. PMID: 40750695
Cell Death Dis

Casein kinase 2 phosphorylates and induces the SALL2 tumor suppressor degradation in colon cancer cells. [Abstract]

2024 Mar 16;15(3):223. PMID: 38493149
Cell Mol Biol Lett

Inhibition of SQSTM1 S403 phosphorylation facilitates the aggresome formation of ubiquitinated proteins during proteasome dysfunction. [Abstract]

2023 Oct 24;28(1):85. PMID: 37872526
Cell Death Discov

CK2α-mediated phosphorylation of GRP94 facilitates the metastatic cascade in triple-negative breast cancer. [Abstract]

2024 Apr 22;10(1):185. PMID: 38649679

Silmitasertib purchased from MedChemExpress. Usage Cited in: Cell Death Discov. 2024 Apr 22;10(1):185. [Abstract]

CK2α kinase activity was measured after treatment with silmitasertib (20 μM, 24 h). Cell lysates were used for in vitro kinase assay to detect the intensity of phosphorylated substrate.
Oncogene

Histone N-terminal acetyltransferase NAA40 links one-carbon metabolism to chemoresistance. [Abstract]

2022 Jan;41(4):571-585. PMID: 34785778
Oncogene

MRE11 stability is regulated by CK2-dependent interaction with R2TP complex. [Abstract]

2017 Aug 24;36(34):4943-4950. PMID: 28436950
Int J Biol Macromol

Critical role of protein kinase CK2 in chronic myeloid leukemia cells harboring the T315I BCR::ABL1 mutation. [Abstract]

2024 Dec 2:138305. PMID: 39631575
EMBO Mol Med

Combined targeting of G protein-coupled receptor and EGF receptor signaling overcomes resistance to PI3K pathway inhibitors in PTEN-null triple negative breast cancer. [Abstract]

2020 Aug 7;12(8):e11987. PMID: 32672423
Cell Rep

SENP3 and USP7 regulate Polycomb-rixosome interactions and silencing functions. [Abstract]

2023 Apr 3;42(4):112339. PMID: 37014752
Transl Psychiatry

Non-gene-edited neural stem cells reverse neuroinflammation and microbiota dysbiosis in a sprague-dawley rat model of autism spectrum disorder. [Abstract]

2026 Apr 1;16(1):275. PMID: 41922322
J Med Chem

Silmitasertib (CX-4945), a Clinically Used CK2-Kinase Inhibitor with Additional Effects on GSK3β and DYRK1A Kinases: A Structural Perspective. [Abstract]

2023 Mar 23;66(6):4009-4024. PMID: 36883902
J Med Chem

Comparative Efficacy and Selectivity of Pharmacological Inhibitors of DYRK and CLK Protein Kinases. [Abstract]

2023 Mar 23;66(6):4106-4130. PMID: 36876904
Cancer Cell Int

Protein kinase CK2 sustains de novo fatty acid synthesis by regulating the expression of SCD-1 in human renal cancer cells. [Abstract]

2024 Dec 26;24(1):432. PMID: 39726006
Biochem Pharmacol

The dual targeting effects of KD025 on casein kinase 2 and ROCK2 in a mouse model of diet-induced obesity. [Abstract]

2025 Apr 8:116933. PMID: 40210126
Cells

Contribution of the CK2 Catalytic Isoforms α and α' to the Glycolytic Phenotype of Tumor Cells. [Abstract]

2021 Jan 18;10(1):181. PMID: 33477590

Silmitasertib purchased from MedChemExpress. Usage Cited in: Cells. 2021 Jan 18;10(1):181. [Abstract]

w.t. SK-N-BE cells were treated with CX-4945 (5-10 μM, 24-48 h) at the indicated time and concentration conditions. 30 μg proteins from lysates were analyzed by WB for the HIF-1α levels. Actin was used as loading control.

Silmitasertib purchased from MedChemExpress. Usage Cited in: Cells. 2021 Jan 18;10(1):181. [Abstract]

SK-N-BE and U2OS cells were analyzed for the extracellular lactate secreted in the culture medium in 6 h, in the absence or in the presence of the indicated concentrations of CX-4945 (5-15 μM).

Silmitasertib purchased from MedChemExpress. Usage Cited in: Cells. 2021 Jan 18;10(1):181. [Abstract]

SK-N-BE cells glycolytic stress test profile, upon treatment with vehicle (control) or the indicated concentration of CX-4945 (2-5 ，μM) for 5 h before running the Seahorse experiment.
Cell Rep Methods

RECOVER identifies synergistic drug combinations in vitro through sequential model optimization. [Abstract]

2023 Oct 23;3(10):100599. PMID: 37797618
Cancer Biol Ther

Targeting the IKZF1/BCL-2 axis as a novel therapeutic strategy for treating acute T-cell lymphoblastic leukemia. [Abstract]

2025 Dec;26(1):2457777. PMID: 39862423
Int J Mol Sci

Transcriptional Regulation of PIK3CD and PIKFYVE in T-Cell Acute Lymphoblastic Leukemia by IKAROS and Protein Kinase CK2. [Abstract]

2021 Jan 15;22(2):819. PMID: 33467550
Int J Mol Sci

Regulation of Small GTPase Rab20 by Ikaros in B-Cell Acute Lymphoblastic Leukemia. [Abstract]

2020 Mar 3;21(5):1718. PMID: 32138279
Invest Ophthalmol Vis Sci

Preclinical Evaluation of Trabectedin in Combination With Targeted Inhibitors for Treatment of Metastatic Uveal Melanoma. [Abstract]

2022 Dec 1;63(13):14. PMID: 36515935
PLoS Pathog

CK2 derived from brain microvascular endothelial cells induces astrocyte inflammatory response in Escherichia coli-induced meningitis. [Abstract]

2025 Sep 10;21(9):e1013464. PMID: 40929057
Sci Rep

Hinokiflavone is a novel CK2 inhibitor promoting apoptosis and synergizing with chemotherapeutic agents in cisplatin resistant bladder cancer cells. [Abstract]

2025 Jul 1;15(1):20922. PMID: 40594996
Cancers (Basel)

Mechanistic Basis for In Vivo Therapeutic Efficacy of CK2 Inhibitor CX-4945 in Acute Myeloid Leukemia. [Abstract]

2021 Mar 5;13(5):1127. PMID: 33807974
Oncol Rep

Inhibition of casein kinase 2 prevents growth of human osteosarcoma. [Abstract]

2017 Feb;37(2):1141-1147. PMID: 27959425

Silmitasertib purchased from MedChemExpress. Usage Cited in: Oncol Rep. 2017 Feb;37(2):1141-1147. [Abstract]

CX-4945 increases the expression of apoptosis markers. Western blot analysis reveals that CX-4945 treatment increases the expression of cleaved PARP or cleaved caspase-3. CX-4945 treatment decreases the expression of Bcl-2 or Bcl-xL. The experiment is performed in triplicate, producing similar results.
iScience

Single-cell and spatial transcriptomics reveal pre-metastatic subsets and therapeutic targets in penile carcinoma. [Abstract]

2025 Jan 7;28(2):111765. PMID: 39925432
J Biol Chem

Nerve injury augments Cacna2d1 transcription via CK2-mediated phosphorylation of the histone deacetylase HDAC2 in dorsal root ganglia. [Abstract]

2024 Nov;300(11):107848. PMID: 39357831
J Immunol

Dephosphorylation of T517 on Hemocyanin Is Required for Antibacterial Activity in Penaeus vannamei. [Abstract]

2023 May 1;210(9):1396-1407. PMID: 36971684
Immunol Cell Biol

RNAi library screening reveals Gβ1, Casein Kinase 2 and ICAP-1 as novel regulators of LFA-1-mediated T cell polarity and migration. [Abstract]

2025 Jan;103(1):73-92. PMID: 39607284
Vet Microbiol

Pseudorabies virus EP0 recruits TECPR2 and CK2 to promote COPII accumulation and viral egress. [Abstract]

2026 Jun 17:320:111115. PMID: 42322707
Biochem Biophys Res Commun

A N-terminally deleted form of the CK2α' catalytic subunit is sufficient to support cell viability. [Abstract]

2020 Oct 20;531(3):409-415. PMID: 32800562
Drug Res (Stuttg)

Preclinical Targeting of the PGRMC1-CK2 Axis with Silmitasertib: A Potential Strategy for Lung Adenocarcinoma Therapy. [Abstract]

2024 Apr;74(4):187-190. PMID: 38508228
bioRxiv

CK2 inhibitor, CX-4945, enhances BH3 priming and promotes apoptosis of venetoclax-resistant AML by targeting antiapoptotic proteins. [Abstract]

2025 Dec 26:2025.12.24.696284. PMID: 41509496
bioRxiv

CK2 inhibitor CX-4945 targets EWS-FLI1 protein abundance and shows anti-tumor activity in metastatic mouse models of Ewing Sarcoma. [Abstract]

2025 Sep 26:2025.09.24.677357. PMID: 41040216
University of Washington

2025.
Patent

US20250228978A1.
bioRxiv

2025 April 09.
bioRxiv

2025 February 07.
bioRxiv

PAIRWISE: Deep Learning-based Prediction of Effective Personalized Drug Combinations in Cancer. [Abstract]

2024 Nov 6:2024.11.04.621884. PMID: 39574568
Heliyon

Comprehensive landscape of gastric cancer-targeted therapy and identification of CSNK2A1 as a potential target. [Abstract]

2024 Aug 18;10(16):e36205. PMID: 39253198
bioRxiv

Spindle morphology changes between meiosis and mitosis driven by CK2 regulation of the Ran pathway. [Abstract]

2024 Jul 25:2024.07.25.605073. PMID: 39211121
Biomed Pharmacother

Pharmacological inhibition of CK2 by silmitasertib mitigates sepsis-induced circulatory collapse, thus improving septic outcomes in mice. [Abstract]

2024 Jul 29:178:117191. PMID: 39079263
bioRxiv

Dissecting signaling regulators driving AXL-mediated bypass resistance and associated phenotypes by phosphosite perturbations. [Abstract]

2023 Oct 23:2023.10.20.563266. PMID: 37961516
Research Square Preprint

2023 Oct 27.
Electronic Theses and Dissertations

2023 Jul.
University of Concepcion

2023.
Research Square Preprint

2023 May 26.
University of California

2023 Feb.
Patent

US20180263995A1.
Oncotarget

CK2 blockade causes MPNST cell apoptosis and promotes degradation of β-catenin. [Abstract]

2016 Aug 16;7(33):53191-53203. PMID: 27448963

Silmitasertib purchased from MedChemExpress. Usage Cited in: Oncotarget. 2016 Aug 16;7(33):53191-53203. [Abstract]

MPNST cell lines show a decrease in CK2 activity in response to escalating CX-4945 concentrations (24 h) as measured by a western blot analysis using anti-CK2 substrate, and to undergo apoptosis as indicated by increased cleaved PARP.

Solvent & Solubility

In Vitro:

DMSO : ≥ 35 mg/mL (100.07 mM; Hygroscopic DMSO has a significant impact on the solubility of product, please use newly opened DMSO)

0.1 M NaOH : 33.33 mg/mL (95.29 mM; ultrasonic and adjust pH to 9 with NaOH)

* "≥" means soluble, but saturation unknown.

View the Complete Stock Solution Preparation Table

Preparing Stock Solutions

View the Complete Stock Solution Preparation Table

Concentration Solvent Mass

1 mg

5 mg

10 mg

Concentration

Solvent

Mass

1 mM

2.8590 mL

14.2951 mL

28.5902 mL

5 mM

0.5718 mL

2.8590 mL

5.7180 mL

10 mM

0.2859 mL

1.4295 mL

2.8590 mL

Please refer to the solubility information to select the appropriate solvent. Once prepared, please aliquot and store the solution to prevent product inactivation from repeated freeze-thaw cycles.

Storage method and period of stock solution: -80°C, 2 years; -20°C, 1 year. When stored at -80°C, please use it within 2 years. When stored at -20°C, please use it within 1 year.

Molarity Calculator

Mass (g) = Concentration (mol/L) × Volume (L) × Molecular Weight (g/mol)

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Dilution Calculator

Concentration _(start) × Volume _(start) = Concentration _(final) × Volume _(final)

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In Vivo:

Select the appropriate dissolution method based on your experimental animal and administration route.

Stock Solution Working Solution

For the following dissolution methods, please ensure to first prepare a clear stock solution using an In Vitro approach and then sequentially add co-solvents:
To ensure reliable experimental results, the clarified stock solution can be appropriately stored based on storage conditions. As for the working solution for In Vivo experiments, it is recommended to prepare freshly and use it on the same day.
The percentages shown for the solvents indicate their volumetric ratio in the final prepared solution. If precipitation or phase separation occurs during preparation, heat and/or sonication can be used to aid dissolution.

Protocol 1

Add each solvent one by one: 10% DMSO 40% PEG300 5% Tween-80 45% Saline

Solubility: 2.08 mg/mL (5.95 mM); Suspended solution; Need ultrasonic

This protocol yields a suspended solution of 2.08 mg/mL. Suspended solution can be used for oral and intraperitoneal injection.

Taking 1 mL working solution as an example, add 100 μL DMSO stock solution (20.8 mg/mL) to 400 μL PEG300, and mix evenly; then add 50 μL Tween-80 and mix evenly; then add 450 μL Saline to adjust the volume to 1 mL.

Protocol 2

Add each solvent one by one: 10% DMSO 90% (20% SBE-β-CD in Saline)

Solubility: 2.08 mg/mL (5.95 mM); Suspended solution; Need ultrasonic

This protocol yields a suspended solution of 2.08 mg/mL. Suspended solution can be used for oral and intraperitoneal injection.

Taking 1 mL working solution as an example, add 100 μL DMSO stock solution (20.8 mg/mL) to 900 μL 20% SBE-β-CD in Saline, and mix evenly.

Working Solution

For the following dissolution methods, please prepare the working solution directly:

It is recommended to prepare fresh solutions and use them promptly within a short period of time.

The percentages shown for the solvents indicate their volumetric ratio in the final prepared solution. If precipitation or phase separation occurs during preparation, heat and/or sonication can be used to aid dissolution.

Protocol 1

Add each solvent one by one: 0.5% CMC-Na/0.5% Tween-80 in Saline water

Solubility: 9.95 mg/mL (28.45 mM); Suspended solution; Need ultrasonic

In Vivo Dissolution Calculator

Please enter the basic information of animal experiments:

Dosage Dosage
mg/kg
Animal Weight (Per Animal) Animal Weight (Per Animal)
g
Dosing Volume (Per Animal) Dosing Volume (Per Animal)
μL
Number of Animals Number of Animals

Recommended: Prepare an additional quantity of animals to account for potential losses during experiments.

Recommended: Prepare an additional quantity of animals to account for potential losses during experiments.

Please enter your animal formula composition:

%
DMSO +

Recommended: Keep the proportion of DMSO in working solution below 2% if your animal is weak.
%
+
+
%
Tween-80 + +
%
Saline +

The co-solvents required include: DMSO, . All of co-solvents are available by MedChemExpress (MCE). , Tween 80. All of co-solvents are available by MedChemExpress (MCE).

Working solution concentration: 0.22 mg/mL

Protocol

Cell Assay^[1]

Various cell lines are seeded at a density of 3,000 cells per well 24 hours prior to treatment, in appropriate media, and then treated with indicated concentrations of Silmitasertib (CX-4945). Suspensions cells are seeded and treated on the same day. Following 4 days of incubation, Alamar Blue (20 μL, 10% of volume per well) is added and the cells are further incubated at 37°C for 4-5 hours. Fluorescence with excitation wavelength at 530-560 nm and emission wavelength at 590 nm is measured.

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

Animal Administration^[1]

Xenografts are initiated by subcutaneous injection of BxPC-3 cells into the right hind flank region of each mouse or BT-474 cells are injected into the mammary fat pad of mice implanted with estrogen pellets. When tumors reach a designated volume of 150-200 mm³, animals are randomized and divided into groups of 9 to 10 mice per group. Silmitasertib (CX-4945) is administered by oral gavage twice daily at 25 or 75 mg/kg for 31 and 35 consecutive days for the BT-474 and BxPC-3 models, respectively. Tumor volumes and body weights are measured twice weekly. The length and width of the tumor are measured with calipers and the volume calculated using the following formula: tumor volume=(length × width²)/2.

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

Purity & Documentation

Select Batch:

Purity: 99.98%

Assay: 99.98%

ee.: 99.98%

Data Sheet (279 KB)
SDS (396 KB)
- English - EN (396 KB)
- Français - FR (396 KB)
- Deutsch - DE (396 KB)
- Norwegian - NO (396 KB)
- Español - ES (396 KB)
- Swedish - SV (396 KB)
- Italian - IT (396 KB)
- Korean - KR (396 KB)
- Portuguese - PT (396 KB)
COA (2659 KB)
Elemental Analysis Report (2659 KB)
HNMR (2659 KB)
CNMR (2659 KB)
RP-HPLC (2659 KB)
NP-HPLC (2659 KB)
MS (2659 KB)
LCMS (2659 KB)
IR (2659 KB)
GC (2659 KB)
OR (2659 KB)
SDS-PAGE (2659 KB)
SEC-HPLC (2659 KB)
Other Report (2659 KB)
Handling Instructions (2659 KB)

References

[1]. Siddiqui-Jain A, et al. CX-4945, an orally bioavailable selective inhibitor of protein kinase CK2, inhibits prosurvival and angiogenic signaling and exhibits antitumor efficacy. Cancer Res. 2010 Dec 15;70(24):10288-98. [Content Brief]

[2]. Buontempo F, et al. Synergistic cytotoxic effects of PS-341 and CK2 inhibitor CX-4945 in acute lymphoblastic leukemia: turning off the prosurvival ER chaperone BIP/Grp78 and turning on the pro-apoptotic NF-κB. Oncotarget. 2016 Jan 12;7(2):1323-40. [Content Brief]

[3]. Chon HJ, et al. The casein kinase 2 inhibitor, CX-4945, as an anti-cancer drug in treatment of human hematological malignancies. Front Pharmacol. 2015 Mar 31;6:70. [Content Brief]

Help & FAQs

How should lyophilized recombinant proteins be reconstituted and stored?

1. Before opening the cap, centrifuge the vial at 13000 rpm for 20-30 seconds. This step will ensure that any lyophilized powder that may have adhered to the cap or walls is collected at the bottom of the vial, minimizing the risk of product loss.

Complete Stock Solution Preparation Table

Storage method and period of stock solution: -80°C, 2 years; -20°C, 1 year. When stored at -80°C, please use it within 2 years. When stored at -20°C, please use it within 1 year.

Optional Solvent	Concentration Solvent Mass	1 mg	5 mg	10 mg	25 mg
0.1 M NaOH / DMSO	1 mM	2.8590 mL	14.2951 mL	28.5902 mL	71.4755 mL
	5 mM	0.5718 mL	2.8590 mL	5.7180 mL	14.2951 mL
	10 mM	0.2859 mL	1.4295 mL	2.8590 mL	7.1476 mL
	15 mM	0.1906 mL	0.9530 mL	1.9060 mL	4.7650 mL
	20 mM	0.1430 mL	0.7148 mL	1.4295 mL	3.5738 mL
	25 mM	0.1144 mL	0.5718 mL	1.1436 mL	2.8590 mL
	30 mM	0.0953 mL	0.4765 mL	0.9530 mL	2.3825 mL
	40 mM	0.0715 mL	0.3574 mL	0.7148 mL	1.7869 mL
	50 mM	0.0572 mL	0.2859 mL	0.5718 mL	1.4295 mL
	60 mM	0.0477 mL	0.2383 mL	0.4765 mL	1.1913 mL
	80 mM	0.0357 mL	0.1787 mL	0.3574 mL	0.8934 mL
DMSO	100 mM	0.0286 mL	0.1430 mL	0.2859 mL	0.7148 mL

Keywords

Silmitasertib

59 Cited Publications

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Silmitasertib

Cell Cycle/DNA Damage Compound Library

Kinase Inhibitor Library

Stem Cell Signaling Compound Library

Wnt/Hedgehog/Notch Compound Library

Anti-Cancer Compound Library

Clinical Compound Library

Autophagy Compound Library

Anti-Aging Compound Library

Drug Repurposing Compound Library

Anti-COVID-19 Compound Library

Endoplasmic Reticulum Stress Compound Library

Orally Active Compound Library

Targeted Diversity Library

Rare Diseases Drug Library

Human Metabolite Library

Non-steroidal Anti-Inflammatory Compound Library

Cancer Stem Cells Compound Library

Heterocyclic Compound Library

Highly Selective Inhibitors Library

Highly Selective Activators Library

Cell Death Library

Serine/Threonine Kinase Inhibitor Library

Multi-Target Compound Library

Bioactive Compound Library Max

Anti-Aging Compound Library Mini

Kinase Inhibitor Library Mini

MCE Bioactive Compound Library

Drug Repurposing Compound Library Plus

Clinical Compound Library Plus

Bioactive Compound Library

Protein Kinase Compound Library

High-Throughput Bioactive Compound Library

Mass Spectrometry Human Metabolite Library

Posttranslational Modification Library

RNA Binding Bioactive Compound Library

Publications Citing Use of MedChemExpress (MCE) Silmitasertib

All Casein Kinase Isoforms

Biological Activity

Chemical Information

Publications (59)

Solvent & Solubility

Protocol

Purity & Documentation

References

Help & FAQs

Complete Stock Solution Preparation Table

Silmitasertib Related Classifications

HY-50855 Related Classifications