10058-F4: Specific c-Myc-Max Dimerization Inhibitor for Apoptosis and Cancer Research

Executive Summary: 10058-F4 is a selective, cell-permeable small-molecule inhibitor that blocks c-Myc-Max heterodimer formation, thereby suppressing c-Myc-driven transcriptional activity in cancer cells (APExBIO). This molecule induces apoptosis via the mitochondrial pathway, with pronounced effects in acute myeloid leukemia (AML) cell lines and prostate cancer xenograft models (Stern et al., 2024). 10058-F4 acts by decreasing c-Myc mRNA and protein levels, leading to cell cycle arrest and cytochrome C release. Its bioavailability and solubility profile support diverse in vitro and in vivo workflows, though efficacy may vary by tumor model and context. The compound's precise mode of action and research-grade formulation make it a reproducible choice for dissecting c-Myc/Max biology and apoptosis mechanisms.

Biological Rationale

c-Myc is a transcription factor essential for cellular proliferation and apoptosis regulation. Its activity in cancer is driven by dimerization with Max, forming a complex that binds DNA and promotes oncogenic transcriptional programs (Stern et al., 2024). Dysregulation of c-Myc is implicated in the pathogenesis of numerous malignancies, including AML and prostate cancer. Inhibiting the c-Myc-Max interaction disrupts downstream transcription, offering a targeted approach to suppress cancer cell survival and proliferation. 10058-F4 directly targets this dimerization event, providing a molecular tool to dissect c-Myc-dependent pathways. Recent studies highlight the interplay between c-Myc, telomerase (TERT), and DNA repair, indicating that c-Myc inhibition may also modulate stem cell maintenance mechanisms and telomere dynamics (Stern et al., 2024).

Mechanism of Action of 10058-F4

10058-F4, chemically designated as (5E)-5-[(4-ethylphenyl)methylidene]-2-sulfanylidene-1,3-thiazolidin-4-one, binds selectively to the c-Myc monomer. This binding blocks the interaction interface required for c-Myc-Max heterodimer formation (APExBIO). As a result, c-Myc cannot occupy E-box sequences on DNA, leading to a reduction in c-Myc-driven transcription. This inhibition downregulates c-Myc mRNA and protein expression and triggers cell cycle arrest in G1 phase. Apoptosis is induced via the mitochondrial pathway, characterized by changes in Bcl-2 family protein expression, mitochondrial membrane depolarization, and cytochrome C release into the cytoplasm. These events activate caspase-dependent cell death. 10058-F4 is cell-permeable, allowing efficient intracellular delivery in both in vitro and in vivo contexts. Its solubility is ≥24.9 mg/mL in DMSO and ≥2.64 mg/mL in ethanol, but it is insoluble in water (APExBIO).

Evidence & Benchmarks

• 10058-F4 inhibits c-Myc-Max dimerization in vitro, confirmed by co-immunoprecipitation and DNA-binding assays (APExBIO).
• Exposure of AML cell lines (HL-60, U937, NB-4) to 100 μM 10058-F4 for 72 hours induces dose-dependent apoptosis, evidenced by Annexin V staining and caspase activation (Stern et al., 2024).
• In vivo, intravenous 10058-F4 inhibits tumor growth in SCID mice with human prostate cancer xenografts (DU145, PC-3), though with variable efficacy depending on tumor type and dose (APExBIO).
• Mechanistic studies confirm cytochrome C release and modulation of Bcl-2 family proteins as key apoptosis signatures following 10058-F4 treatment (cytochrome-c-fragment.com).
• RNA-seq profiling after c-Myc inhibition demonstrates transcriptome-wide downregulation of c-Myc target genes, including those involved in cell cycle progression and metabolism (Stern et al., 2024).

Applications, Limits & Misconceptions

10058-F4 is widely used in apoptosis assays, acute myeloid leukemia research, and studies of prostate cancer models. Its specificity makes it a preferred tool for studying c-Myc/Max heterodimer disruption and downstream apoptotic pathways. The compound is valuable for modulating telomerase (TERT) expression, providing insights into stem cell maintenance and aging (Stern et al., 2024). Integration with qPCR, flow cytometry, and western blot analyses enables multi-level validation of c-Myc pathway inhibition.

• 10058-F4: Small-Molecule c-Myc Inhibitor for Advanced Apoptosis Research: This article focuses on optimized protocols and troubleshooting, while the current review provides a mechanistic synthesis and evidence-based summary.
• Disrupting c-Myc/Max: Strategic Insights and Translational Promise: The present article extends the translational perspective by adding quantitative benchmarks and clarifying solubility/application limits.
• 10058-F4 (SKU A1169): Data-Driven Strategies for Reliable Apoptosis Assays: That resource is scenario-driven; here, we emphasize primary literature integration and mechanistic clarity.

Common Pitfalls or Misconceptions

• 10058-F4 is not water-soluble; attempts to prepare aqueous solutions result in precipitation and loss of efficacy.
• It does not inhibit c-Myc transcription directly, but blocks dimerization with Max, affecting DNA binding and downstream activity.
• The compound is not suitable for long-term solution storage; stock solutions should be freshly prepared due to instability in solution.
• Efficacy varies by cell line and tumor model; some resistant lines may not respond at standard concentrations.
• 10058-F4 is for research use only and is not approved for clinical application or therapeutic intervention.

Workflow Integration & Parameters

10058-F4 is typically reconstituted in DMSO at ≥24.9 mg/mL for in vitro experiments. Working concentrations range from 10–100 μM, with exposure times of 24–72 hours depending on cell type and assay endpoint. For in vivo studies, intravenous administration is effective in mouse xenograft models, with dosing regimens tailored to tumor type and progression. The product is supplied as a solid and should be stored at -20°C. APExBIO recommends avoiding repeated freeze-thaw cycles and using reconstituted solutions promptly. Integration with apoptosis assays (Annexin V/PI), cell cycle analysis, and transcriptomic profiling enhances research value. See the 10058-F4 product page for detailed preparation and storage guidelines.

Conclusion & Outlook

10058-F4 is a rigorously validated, cell-permeable c-Myc-Max dimerization inhibitor that enables detailed interrogation of oncogenic transcription and apoptosis mechanisms. Its quantitative efficacy in AML and prostate cancer models, combined with precise mode of action and comprehensive documentation, position it as an indispensable tool for cancer biology and apoptosis research. Ongoing discoveries in telomerase and DNA repair regulation further expand its utility (Stern et al., 2024). For advanced protocols, troubleshooting, and translational perspectives, APExBIO and referenced resources provide actionable guidance for the research community.