10058-F4: Precision c-Myc-Max Dimerization Inhibition for Apoptosis and Cancer Research

Executive Summary: 10058-F4 is a well-characterized, small-molecule inhibitor that selectively disrupts the c-Myc-Max dimer, a critical driver of oncogenic transcription (https://doi.org/10.1101/2024.09.16.613267). This compound is cell-permeable, acting directly on intracellular targets to suppress c-Myc-driven transcriptional programs. Quantitative studies confirm its efficacy in acute myeloid leukemia and prostate cancer models, with apoptosis induction observed at 100 μM after 72 hours (https://www.apexbt.com/10058-f4.html). 10058-F4 also modulates mitochondrial apoptosis pathways, affecting Bcl-2 family proteins and cytochrome C release. Its strict solubility and storage requirements are essential for reproducible results, making it indispensable for apoptosis assay workflows and c-Myc pathway interrogation.

Biological Rationale

c-Myc is a nuclear transcription factor controlling cell proliferation, metabolism, and apoptosis. Its oncogenic activity depends on heterodimerization with Max, enabling DNA binding and gene regulation. Dysregulation of c-Myc-Max activity is implicated in tumorigenesis, notably in acute myeloid leukemia (AML) and prostate cancer. In human pluripotent stem cells, c-Myc-Max complexes maintain telomerase (TERT) expression, contributing to stem cell immortality and cancer cell survival (https://doi.org/10.1101/2024.09.16.613267). Targeting the c-Myc-Max interaction provides a direct approach to modulate these pathways without affecting upstream signaling. 10058-F4 was developed to selectively disrupt this protein–protein interface, providing a research tool for dissecting c-Myc-dependent oncogenic processes.

Mechanism of Action of 10058-F4

10058-F4, chemically (5E)-5-[(4-ethylphenyl)methylidene]-2-sulfanylidene-1,3-thiazolidin-4-one, specifically binds to c-Myc, preventing its dimerization with Max. This inhibition blocks the formation of the c-Myc-Max complex, thereby preventing their binding to E-box DNA sequences. As a result, c-Myc-driven transcriptional activity is suppressed. Downstream, this leads to decreased c-Myc mRNA and protein levels. The disruption of c-Myc-Max also induces cell cycle arrest and triggers mitochondrial apoptosis, characterized by changes in Bcl-2 family protein expression and cytochrome C release (https://www.apexbt.com/10058-f4.html). In pluripotent stem cells, inhibition of c-Myc-Max dimerization results in rapid accumulation of the repressive H3K27me3 histone mark at the TERT promoter, reducing telomerase transcription (https://doi.org/10.1101/2024.09.16.613267).

Evidence & Benchmarks

• 10058-F4 induces dose-dependent apoptosis in AML cell lines (HL-60, U937, NB-4), with significant cell death observed at 100 μM after 72 hours (https://www.apexbt.com/10058-f4.html).
• In human prostate cancer xenograft models (DU145, PC-3) in SCID mice, intravenous 10058-F4 administration inhibits tumor growth, though with variable efficacy depending on the tumor line (https://www.apexbt.com/10058-f4.html).
• Inhibition of c-Myc-Max dimerization in human pluripotent stem cells leads to rapid gain of H3K27me3 at the TERT promoter and suppression of telomerase transcription (https://doi.org/10.1101/2024.09.16.613267).
• 10058-F4 acts directly on the c-Myc-Max interface, leaving upstream MAPK signaling and unrelated transcription factors largely unaffected under tested conditions (https://doi.org/10.1101/2024.09.16.613267).
• Solubility benchmarks: ≥24.9 mg/mL in DMSO, ≥2.64 mg/mL in ethanol, but insoluble in water; correct solvent handling is critical for activity (https://www.apexbt.com/10058-f4.html).

This article extends the mechanistic detail provided in Disrupting c-Myc/Max: Strategic Pathways by providing explicit quantitative results and workflow constraints for 10058-F4.

For a more competitive landscape overview and integration with DNA repair findings, see Disrupting the c-Myc/Max Axis: Mechanistic Advances; this article clarifies solvent and storage conditions not previously detailed.

Applications, Limits & Misconceptions

10058-F4 is primarily used in research on:

• Acute myeloid leukemia (AML) apoptosis assays.
• Prostate cancer xenograft models.
• Dissection of c-Myc/Max-dependent transcription in stem cells and cancer.
• Elucidation of mitochondrial apoptosis mechanisms via Bcl-2 modulation.
• Analysis of telomerase (TERT) transcriptional regulation in pluripotent cells.

It should not be used as a general cytotoxic agent nor as a substitute for upstream pathway inhibitors.

Common Pitfalls or Misconceptions

• 10058-F4 is not effective in models where c-Myc activity is not required for cell survival.
• It does not inhibit Max homodimerization or unrelated bHLH-Zip transcription factors.
• Incorrect solvent selection (e.g., water) results in insolubility and loss of activity.
• Long-term storage of prepared solutions is not recommended; use freshly prepared aliquots to ensure potency.
• Variable efficacy in vivo may occur due to pharmacokinetics or tumor heterogeneity.

Workflow Integration & Parameters

For optimal results, dissolve 10058-F4 in DMSO (≥24.9 mg/mL) or ethanol (≥2.64 mg/mL). Avoid water as a solvent. Store the solid at -20°C; do not store prepared solutions long-term. Typical usage in AML and prostate cancer models involves 100 μM concentrations for 48–72 hours. In vivo, intravenous dosing in SCID mice is used for xenograft studies. For apoptosis assays, include controls for solvent and time, and monitor effects on mitochondrial proteins and cytochrome C. When assaying telomerase regulation, combine with ChIP or qPCR for H3K27me3 and TERT expression. Detailed protocols for apoptosis assays and troubleshooting guidance can be found in 10058-F4: Optimizing Apoptosis Assays; this article emphasizes the critical importance of solvent, storage, and experimental timing.

Conclusion & Outlook

10058-F4 serves as a precise, mechanistically validated tool for dissecting c-Myc-Max-dependent pathways in cancer and stem cell research. Its direct mode of action and benchmarked efficacy in apoptosis and telomerase regulation make it indispensable for translational and preclinical workflows. As mechanistic understanding of c-Myc-driven oncogenesis expands, 10058-F4 will remain a reference standard for targeted inhibition in experimental systems. For detailed product specifications and ordering information, refer to the 10058-F4 product page.