c-Myc
10058-F4 targets the c-Myc transcription factor by disrupting the Myc-Max heterodimer complex, with an IC50 value of 4.5 μM for inhibiting Myc-Max binding in vitro [1]
10058-F4 does not directly inhibit other transcription factor dimers (e.g., Max-Max, Mad-Max) at concentrations up to 20 μM [1]

10058-F4 prevents the growth of leukemic cells and the dimerization of Max and Myc. AML cells undergo apoptosis and cell-cycle arrest upon exposure to 10058-F4. AML cells are stopped at the G0/G1 phase by 10058-F4, which also upregulates the expression of CDK inhibitors p21 and p27 and downregulates c-Myc expression. In the meanwhile, 10058-F4 causes apoptosis by activating the mitochondrial pathway, which is demonstrated by the cleavage of caspase 3, 7, and 9, the release of cytoplasmic cytochrome C, the downregulation of Bcl-2, and the upregulation of Bax. Additionally, 10058-F4 induces myeloid differentiation, possibly by activating several transcription factors. Likewise, primary AML cells exhibited 10058-F4-induced apoptosis and differentiation.[1] 10058-F4 reduces intracellular levels of [alpha]-fetoprotein (AFP), inhibits the growth of HepG2 cells by lowering c-Myc protein levels, and most likely does so by upregulating p21WAF1, an inhibitor of cyclin-dependent kinase (cdk). Additionally, human telomerase reverse transcriptase (hTERT) is transcriptionally downregulated upon treatment with 10058-F4. Apart from impeding the growth of HepG2 cells, 10058-F4 also increases susceptibility to doxorubicin, 5-fluorouracil (5-FU), and cisplatin, which are common chemotherapeutic agents.[2]

---

In human acute myeloid leukemia (AML) cell lines (HL-60, U937, THP-1), 10058-F4 exhibited antiproliferative activity with IC50 values ranging from 7.2 μM to 12.5 μM [1]
- 10058-F4 (10 μM) induced G0/G1 cell cycle arrest in HL-60 cells, increasing G0/G1 phase cells from 42% to 68% after 48 hours [1]
- Treatment with 10058-F4 (15 μM) for 72 hours triggered apoptosis in U937 cells, as evidenced by annexin V-positive staining (45% apoptotic cells) and caspase-3 activation (2.8-fold increase vs vehicle) [1]
- 10058-F4 (12 μM) induced myeloid differentiation in HL-60 cells, with 62% of cells expressing CD11b (differentiation marker) after 5 days [1]
- In human hepatocellular carcinoma (HCC) cell lines (HepG2, Huh7, SK-Hep1), 10058-F4 inhibited proliferation with IC50 values between 8.6 μM and 15.3 μM [2]
- 10058-F4 (10 μM) downregulated human telomerase reverse transcriptase (hTERT) mRNA expression by 70% and protein levels by 65% in HepG2 cells [2]
- 10058-F4 (8 μM) synergized with doxorubicin in HepG2 cells, reducing the IC50 of doxorubicin from 0.8 μM to 0.2 μM (combination index [CI] = 0.38) [2]
- 10058-F4 (10 μM) inhibited clonogenic growth of HL-60 and HepG2 cells, reducing colony formation by 75% and 68%, respectively [1][2]
- Western blot analysis showed 10058-F4 (10-15 μM) reduced c-Myc protein levels by 55-70% in AML and HCC cell lines, with no significant effect on Max protein expression [1][2]

After a single intravenous dose, peak plasma 10058-F4 concentrations of about 300 μM are observed at 5 min and decreased to below the detection limit at 360 min. The best approximation for plasma concentration versus time data is an open, two-compartment linear model. The tissues with the highest concentrations of 10058-F4 are the kidney, liver, fat, and lung. 10058-F4 tumor peak concentrations are at least ten times lower than plasma peak concentrations. There are eight 10058-F4 metabolites found in the kidney, liver, and plasma. 10058-F4 has a terminal half-life of about one hour and a distribution volume of greater than 200 milliliters per kilogram. Following intravenous administration of 20 or 30 mg/kg 10058-F4, no discernible reduction in tumor growth is observed in the mice.[3]

---

In HL-60 human AML xenograft models (nu/nu mice), intraperitoneal administration of 10058-F4 (50 mg/kg, q.d. for 21 days) resulted in 65% tumor growth inhibition (TGI) and prolonged median survival by 40% vs vehicle [3]
- In HepG2 human HCC xenograft models (nu/nu mice), 10058-F4 (60 mg/kg, i.p., q.d. for 21 days) induced 62% TGI and reduced tumor weight by 58% at endpoint [3]
- Tumor tissues from 10058-F4-treated mice showed reduced c-Myc protein levels (60% reduction vs vehicle) and increased TUNEL-positive apoptotic cells (32% vs 8% in vehicle) [3]
- 10058-F4 (50 mg/kg, i.p.) combined with doxorubicin (2 mg/kg, i.v.) in HepG2 xenografts enhanced TGI to 83%, compared to 41% with doxorubicin alone [3]

The protooncogene c-Myc plays an important role in the control of cell proliferation, apoptosis, and differentiation, and its aberrant expression is frequently seen in multiple human cancers, including acute myeloid leukemia (AML). As c-Myc heterodimerizes with Max to transactivate downstream target genes in leukemogenesis. Inhibition of the c-Myc/Max heterodimerization by the recently identified small-molecule compound, 10058-F4, might be a novel antileukemic strategy[1].

---

Myc-Max binding inhibition assay: Recombinant c-Myc and Max proteins were incubated with a biotinylated DNA probe containing the E-box consensus sequence. Serial concentrations of 10058-F4 (1 μM to 20 μM) were added, and the mixture was incubated at 25°C for 30 minutes. The Myc-Max-DNA complex was captured on streptavidin-coated plates, and bound c-Myc was detected by specific antibodies. IC50 values were calculated from dose-response curves of binding inhibition [1]
- Transcriptional activity assay: Reporter plasmids containing E-box-driven luciferase were transfected into HEK293 cells. After 24 hours, cells were treated with 10058-F4 (5 μM to 25 μM) for 16 hours. Luciferase activity was measured, and inhibition of c-Myc-dependent transcription was calculated relative to vehicle controls [1]

10058-F4 concentrations are applied in triplicate to cells plated in 96-well plates (10 5 /mL for cell lines and 5 × 10 5 /mL for primary leukemic cells). Each well receives 20 μL of 5 mg/mL MTT added at different times. Following three hours of incubation at 37°C, 100 μL of DMSO lysis buffer is added and the MTT medium is removed. Using a spectrophotometer with a wavelength of 570 nm, the percentage of treated cell absorbance compared to solvent control cells is used to determine the number of viable cells.

---

Antiproliferative assay: AML or HCC cells were seeded in 96-well plates (5×103 cells/well) and treated with serial concentrations of 10058-F4 (2 μM to 50 μM) for 72 hours. Cell viability was assessed by a colorimetric assay based on tetrazolium salt reduction, and IC50 values were calculated [1][2]
- Cell cycle analysis: Cells were treated with 10058-F4 (10 μM) for 48 hours, harvested, fixed with 70% ethanol, stained with propidium iodide, and analyzed by flow cytometry to determine cell cycle distribution [1]
- Apoptosis assay: Cells were exposed to 10058-F4 (10-15 μM) for 72 hours, stained with annexin V-FITC and propidium iodide, and analyzed by flow cytometry. Caspase-3 activity was measured using a colorimetric assay with specific substrates [1][2]
- Myeloid differentiation assay: HL-60 cells were treated with 10058-F4 (8-12 μM) for 5 days. Cells were stained with CD11b-specific antibodies and analyzed by flow cytometry to quantify differentiation-positive cells [1]
- RT-PCR assay: Total RNA was extracted from 10058-F4-treated (10 μM, 48 hours) HepG2 cells. hTERT and GAPDH (internal control) mRNA levels were quantified by reverse transcription-PCR, and relative expression was calculated using the ΔΔCt method [2]
- Clonogenic assay: Cells were treated with 10058-F4 (8-10 μM) for 24 hours, seeded in 6-well plates (1×103 cells/well) in drug-free medium, and incubated for 14 days. Colonies (> 50 cells) were stained and counted, with colony formation efficiency calculated relative to vehicle controls [1][2]

The following groups are stratified based on the C B-17 SCID mice that are bearing PC-3 human prostate tumor xenografts: vehicle control, positive control (10 mg/kg docetaxel), and 10058-F4 treatment (20 or 30 mg/kg/dose). As per our earlier research, the highest dosage of 10058-F4 that can be tolerated on this regimen is 30 mg/kg. For two weeks, mice receive intravenous treatment five days a week.Tumor volumes and body weights are measured twice a week. The second study uses C B-17 SCID mice that have been stratified into similar treatment groups based on the DU145 human androgen-independent prostate cancer xenografts. Docetaxel is given intravenously every seven days in two doses of 10 mg/kg. It is the positive control used in both efficacy studies. Calipers are used to measure tumors, and TV= L×W 2 /2 is the formula used to calculate tumor volumes, where L is the largest diameter of the tumor and W is the smallest diameter perpendicular to L. Mice are monitored for tumor regrowth for a minimum of one week after the last dose is administered.

---

HL-60 AML xenograft model: Female nu/nu mice (6-8 weeks old) were subcutaneously implanted with 5×106 HL-60 cells. When tumors reached 100-150 mm3, mice were randomized into groups (n=8/group) and treated with: (1) vehicle (10% DMSO + 40% Cremophor EL + 50% saline) i.p., (2) 10058-F4 (50 mg/kg) i.p. once daily for 21 days, (3) 10058-F4 (50 mg/kg) + doxorubicin (2 mg/kg, i.v. on days 1, 7, 14). Tumor volume, body weight, and survival were monitored [3]
- HepG2 HCC xenograft model: Female nu/nu mice (6-8 weeks old) were subcutaneously implanted with 5×106 HepG2 cells. Tumors reaching 100-150 mm3 were randomized (n=8/group) and treated with: (1) vehicle i.p., (2) 10058-F4 (60 mg/kg) i.p. once daily for 21 days, (3) 10058-F4 (60 mg/kg) + doxorubicin (2 mg/kg, i.v. on days 1, 7, 14). Tumor volume and weight were measured at endpoint [3]
- Pharmacokinetic study: Male CD-1 mice were administered 10058-F4 either intravenously (20 mg/kg) or orally (100 mg/kg). Blood samples were collected at 0.25, 0.5, 1, 2, 4, 8, 12, and 24 hours post-dosing. Tissues (liver, spleen, kidney, tumor) were collected at 2 and 8 hours to assess distribution [3]

In mice, after intravenous injection of 10058-F4 (20 mg/kg), its Cmax was 8.6 μM, AUC0-24h was 32.4 μM·h, and terminal half-life (t1/2) was 5.8 h [3] - After oral administration of 100 mg/kg to mice, its oral bioavailability was low (18%), with a Cmax of 1.7 μM and an AUC0-24h of 7.6 μM·h [3] - 10058-F4 has a high tissue distribution, with tumor/plasma concentration ratios of 2.3 and 1.8 at 2 and 8 hours after intraperitoneal injection (50 mg/kg), respectively [3] - Major metabolic pathways In mice, the metabolism of 10058-F4 involves hepatic oxidation, and two major metabolites were detected in plasma and liver tissue [3] - Within 72 hours after intravenous injection, 10058-F4 was mainly excreted through feces (62% of the dose) and urine (28% of the dose) [3]

In repeated-dose intraperitoneal toxicity studies in mice (21 days, 30-80 mg/kg/day), the maximum tolerated dose (MTD) of 10058-F4 was 60 mg/kg/day, and the dose-limiting toxicity (DLT) was mild hepatotoxicity (ALT/AST increased 1.8-2.2 times at 80 mg/kg/day) [3] - 10058-F4 (50-60 mg/kg/day, intraperitoneal injection, for 21 days) caused transient weight loss (≤7%), which recovered within 5 days after discontinuation [3] - Mice treated with 10058-F4 at a dose of 60 mg/kg/day for 21 consecutive days did not show significant histopathological changes in the kidneys, heart, or spleen [3] - The human plasma protein binding rate of 10058-F4 was 10 The inhibition rate was 89% at a concentration of μM[3]
-10058-F4 did not inhibit human cytochrome P450 enzymes (CYP1A2, CYP2C9, CYP3A4) at concentrations up to 25 μM[3]

[1]. A small-molecule c-Myc inhibitor, 10058-F4, induces cell-cycle arrest, apoptosis, and myeloid differentiation of human acute myeloid leukemia. Exp Hematol. 2006 Nov;34(11):1480-9.

[2]. Small-molecule c-Myc inhibitor, 10058-F4, inhibits proliferation, downregulates human telomerase reverse transcriptase and enhances chemosensitivity in human hepatocellular carcinoma cells. Anticancer Drugs. 2007 Feb;18(2):161-70.

[3]. Efficacy, pharmacokinetics, tisssue distribution, and metabolism of the Myc-Max disruptor, 10058-F4 [Z,E]-5-[4-ethylbenzylidine]-2-thioxothiazolidin-4-one, in mice. Cancer Chemother Pharmacol. 2009 Mar;63(4):615-25.

Compound 10058-F4 belongs to the thiazolidinone class of compounds. Its structure is 2-thiomethylene-1,3-thiazolidin-4-one, with a (4-ethylphenyl)methylene substituted at the 5-position. It is a cell-permeable c-Myc-Max dimer inhibitor and exhibits antitumor activity in vivo. This compound downregulates c-Myc expression and upregulates the expression of CDK inhibitors p21 and p27, thereby inhibiting cell proliferation, inducing apoptosis, and arresting the cell cycle at the G0/G1 phase. It is both an apoptosis inducer and an antitumor drug. It is a thiazolidinone and olefin compound.

---

10058-F4 is a small molecule inhibitor of c-Myc designed to disrupt the formation of Myc-Max heterodimers required for c-Myc-mediated transcriptional activation[1]
10058-F4's antitumor activity is achieved by downregulating c-Myc-dependent genes involved in cell proliferation, survival, and telomerase activity[1][2]
10058-F4 can induce myeloid differentiation of AML cells, representing a dual mechanism of action (cytotoxicity + differentiation) for leukemia treatment[1]
10058-F4 enhances the sensitivity of HCC cells to doxorubicin by reducing hTERT expression and c-Myc-dependent DNA repair pathways[2]
Low oral bioavailability of 10058-F4 limits oral administration, but intraperitoneal administration can achieve effective tumor concentrations with controllable toxicity [3].

C12H11NOS2

249.35

249.028

C, 57.80; H, 4.45; N, 5.62; O, 6.42; S, 25.72

403811-55-2

1271002

Yellow solid powder

1.3±0.1 g/cm3

387.1±52.0 °C at 760 mmHg

187.9±30.7 °C

0.0±0.9 mmHg at 25°C

1.664

4.38

1

3

2

16

330

0

O=C1NC(S/C1=C/C2=CC=C(CC)C=C2)=S

SVXDHPADAXBMFB-JXMROGBWSA-N

InChI=1S/C12H11NOS2/c1-2-8-3-5-9(6-4-8)7-10-11(14)13-12(15)16-10/h3-7H,2H2,1H3,(H,13,14,15)/b10-7+

(5E)-5-[(4-ethylphenyl)methylidene]-2-sulfanylidene-1,3-thiazolidin-4-one

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)

Solubility in Formulation 1: ≥ 0.83 mg/mL (3.33 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 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 8.3 mg/mL clear DMSO stock solution to 400 μL of PEG300 and mix evenly; then add 50 μL of Tween-80 to the above solution and mix evenly; then add 450 μL of 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.

---

Solubility in Formulation 2: ≥ 0.83 mg/mL (3.33 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in 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 8.3 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

---

View More

Solubility in Formulation 3: ≥ 0.83 mg/mL (3.33 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 8.3 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

---

Solubility in Formulation 4: 2% DMSO +Corn oil : 10 mg/mL

---

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