10074-G5: A Small-Molecule c-Myc/Max Inhibitor for Cancer Research

Executive Summary: 10074-G5 is a crystalline small-molecule inhibitor targeting c-Myc/Max dimerization, a key step in oncogenic transcription factor activation (APExBIO). It induces cell-cycle arrest and apoptosis in multiple cancer models at micromolar concentrations, with benchmark IC50 values of 15.6 ± 1.5 μM (Daudi) and 13.5 ± 2.1 μM (HL-60) (García-Castillo et al., 2025). In vivo, intravenous dosing at 20 mg/kg for 10 days suppresses tumor xenograft growth without significant toxicity. 10074-G5 is insoluble in water but has high solubility in DMSO (≥37.9 mg/mL) and moderate solubility in ethanol (≥3.53 mg/mL, ultrasound-assisted). The compound is a core research tool for interrogating c-Myc-driven oncogenic pathways, apoptosis assays, and anticancer drug development (see benchmark review).

Biological Rationale

c-Myc is a basic helix-loop-helix leucine zipper (bHLH-ZIP) transcription factor. It regulates genes involved in cell cycle progression, growth, metabolism, differentiation, and apoptosis. Overexpression of c-Myc is observed in diverse cancers, including prostate, breast, colon, pancreatic, lung, B-cell lymphoma, and leukemias (García-Castillo et al., 2025). Elevated c-Myc levels are associated with cancer aggressiveness and poor prognosis. In esophageal adenocarcinoma (EAC), the MYC/TERT/NFκB axis is upregulated and drives invasive phenotypes. MicroRNA-196a overexpression leads to c-Myc accumulation, reinforcing oncogenic signaling and epithelial-mesenchymal transition (EMT) (DOI). Targeting the c-Myc/Max dimerization interface can disrupt this axis, offering a rational strategy for modulating cancer progression.

Mechanism of Action of 10074-G5

10074-G5 is a small-molecule inhibitor that selectively disrupts the c-Myc/Max heterodimerization required for DNA binding and oncogenic transcriptional activity (APExBIO). It binds to the c-Myc bHLH-ZIP domain, preventing interaction with Max and thereby abrogating downstream gene activation. Treatment with 10074-G5 at 10 μM effectively inhibits c-Myc/Max dimerization and decreases total c-Myc protein levels in vitro (review). This leads to cell-cycle arrest (G1 phase) and induction of apoptosis in c-Myc-dependent tumor cells. The compound also triggers tumor vascular degeneration and promotes tumor cell redifferentiation in xenograft models.

Evidence & Benchmarks

• 10074-G5 inhibits c-Myc/Max dimerization in vitro at 10 μM, reducing c-Myc protein levels (APExBIO, product page).
• IC50 values: 15.6 ± 1.5 μM for Daudi cells; 13.5 ± 2.1 μM for HL-60 cells; measured by cell viability assays (García-Castillo et al., 2025).
• Intravenous administration at 20 mg/kg daily for 10 days significantly suppresses Daudi xenograft tumor growth without affecting body weight (APExBIO, C5722).
• High solubility in DMSO (≥37.9 mg/mL) and ethanol (≥3.53 mg/mL, with ultrasound), insoluble in water. Storage at -20°C is recommended (APExBIO, specs).
• c-Myc inhibition reverses EMT-associated phenotypes in miR-196a-overexpressing esophageal adenocarcinoma cells (García-Castillo et al., 2025).
• Apoptosis induction and cell cycle arrest validated in multiple cancer cell lines (site review).

Applications, Limits & Misconceptions

10074-G5 is primarily used in preclinical cancer research for:

• Dissecting c-Myc-driven oncogenic pathways.
• Apoptosis assays and cell cycle arrest studies.
• Tumor regression and redifferentiation models.
• Evaluating the c-Myc/TERT/NFκB axis in solid and hematologic malignancies (DOI).

For a broader mechanistic context, see Targeting the c-Myc/Max Axis with 10074-G5, which delves into recent microRNA-driven oncogenic mechanisms and highlights strategic use in translational research — this article provides an up-to-date experimental and application-focused synthesis.

Common Pitfalls or Misconceptions

• 10074-G5 is not suitable for direct in vivo oral dosing due to low bioavailability and water insolubility.
• It is not a pan-cancer cytotoxic agent; efficacy requires c-Myc-dependent cell models.
• It does not inhibit non-c-Myc transcription factors or unrelated dimerization interfaces.
• Long-term solution storage is not recommended; compound stability is best maintained by fresh preparation and -20°C storage.
• Observed effects may be confounded by compound precipitation in aqueous buffers; ensure appropriate solubilization protocols.

Workflow Integration & Parameters

10074-G5 (APExBIO, C5722 kit) is typically dissolved in DMSO at ≥37.9 mg/mL or in ethanol at ≥3.53 mg/mL (ultrasonic assistance). Working concentrations for in vitro assays commonly range from 1 to 20 μM, with 10 μM as a validated benchmark for disrupting c-Myc/Max dimerization. In vivo, intravenous injection at 20 mg/kg per day for 10 days is effective for tumor regression in Daudi xenograft models. Solutions should be freshly prepared and filtered. Compound purity is generally 98%, and storage at -20°C is advised. For troubleshooting and advanced protocols, the workflow described in this advanced workflow guide goes beyond application basics covered in this article, addressing troubleshooting and benchmark calibration.

Conclusion & Outlook

10074-G5 is a rigorously benchmarked small-molecule c-Myc inhibitor that enables targeted disruption of oncogenic transcriptional networks in cancer research. Its validated efficacy in apoptosis, cell cycle arrest, and tumor regression studies positions it as a core tool for anticancer drug development and mechanistic pathway interrogation. For updated best practices and protocol optimization, researchers are encouraged to consult both the official product page and recent literature (García-Castillo et al., 2025). As research on the c-Myc/TERT/NFκB axis advances, 10074-G5 from APExBIO remains central to translational and preclinical oncology workflows.