YC-1: Soluble Guanylyl Cyclase Activator & HIF-1α Inhibitor for Cancer Research

Executive Summary: YC-1 (5-(1-benzyl-1H-indazol-3-yl)furan-2-yl)methanol is a crystalline, small-molecule activator of soluble guanylyl cyclase (sGC) and a post-transcriptional inhibitor of hypoxia-inducible factor-1α (HIF-1α) [APExBIO]. It demonstrates in vitro inhibition of HIF-1 transcriptional activity with an IC₅₀ of 1.2 µM under hypoxic conditions. YC-1 also inhibits platelet aggregation and vascular contraction by sGC activation, supporting its role in circulatory disorder models [Related]. In vivo, YC-1 reduces tumor size and vascularization by downregulating HIF-1α and its target genes. The compound is soluble at ≥30.4 mg/mL in DMSO and ≥16.2 mg/mL in ethanol, but insoluble in water.

Biological Rationale

Hypoxia-inducible factor-1α (HIF-1α) orchestrates cellular adaptation to oxygen deprivation by upregulating genes involved in angiogenesis, metabolism, and survival. Many solid tumors overexpress HIF-1α, promoting growth, metastasis, and resistance to therapy. Targeting HIF-1α is a validated approach for limiting tumor progression and angiogenesis [See contrast: This article details post-transcriptional inhibition and workflow integration, extending beyond basic mechanism]. In parallel, soluble guanylyl cyclase (sGC) is a key effector of nitric oxide (NO) signaling, regulating vasodilation and cGMP-dependent pathways. Pharmacologic activation of sGC offers therapeutic avenues in vascular disorders and enhances anti-angiogenic strategies in oncology. YC-1 uniquely combines these mechanisms, making it valuable for dissecting hypoxia and cGMP signaling in cancer and vascular biology.

Mechanism of Action of YC-1 (5-(1-benzyl-1H-indazol-3-yl)furan-2-yl)methanol

YC-1 acts as a dual modulator:

• HIF-1α Inhibition: YC-1 inhibits HIF-1α protein accumulation at the post-transcriptional level under hypoxic conditions, thereby blocking HIF-1-dependent transcriptional activity and downstream gene expression [Clarifies how YC-1's specificity enables reference-grade pathway studies]. This effect is independent of sGC activation and is associated with the oxygen-sensing pathway.
• sGC Activation: YC-1 stimulates sGC activity, leading to enhanced conversion of GTP to cGMP. Elevated cGMP mediates vasorelaxation, inhibits platelet aggregation, and modulates smooth muscle tone. This mechanism underlies its utility in circulatory disorder models.

These actions are concentration-dependent and have been validated in vitro and in vivo.

Evidence & Benchmarks

• YC-1 inhibits hypoxia-induced HIF-1 transcriptional activity with an IC₅₀ of 1.2 µM in cell-based luciferase reporter assays (https://www.apexbt.com/yc-1.html).
• Post-transcriptional inhibition of HIF-1α by YC-1 results in reduced VEGF and GLUT1 expression in tumor models (https://tofacitinib.biz/index.php?g=Wap&m=Article&a=detail&id=113).
• In vivo, YC-1 treatment yields smaller, less vascularized tumors in murine xenograft models, with lower HIF-1α and angiogenesis marker expression (https://3x-flag-peptide.com/index.php?g=Wap&m=Article&a=detail&id=119).
• YC-1 activates sGC in isolated vascular tissue, leading to cGMP-dependent vasorelaxation at concentrations ≥1 µM (https://laminin-925-933.com/index.php?g=Wap&m=Article&a=detail&id=132).
• YC-1 inhibits platelet aggregation via sGC activation, as demonstrated in in vitro human platelet assays (https://tofacitinib.biz/index.php?g=Wap&m=Article&a=detail&id=122).
• YC-1 solutions are stable for short-term use in DMSO (≥30.4 mg/mL) or ethanol (≥16.2 mg/mL), but are unstable in aqueous buffers (https://www.apexbt.com/yc-1.html).

Applications, Limits & Misconceptions

Applications:

• Cancer Biology: Inhibits HIF-1α-driven gene expression, tumor angiogenesis, and growth in solid tumor models.
• Vascular Biology: Enhances sGC activity, enabling studies of cGMP signaling, vasodilation, and platelet aggregation.
• Hypoxia Pathway Analysis: Dissects oxygen-sensing responses in cellular and animal models.
• Pharmacological Screening: Serves as a benchmark compound for evaluating HIF-1α or cGMP pathway modulators.

Common Pitfalls or Misconceptions

• YC-1 is not a direct nitric oxide donor; its sGC activation is NO-independent.
• It is not suitable for aqueous formulations due to poor water solubility.
• Effects on HIF-1α are post-transcriptional; it does not block mRNA synthesis.
• YC-1 is intended for research use only; not for clinical or diagnostic applications.
• Long-term storage of solutions is not recommended; use freshly prepared aliquots.

Workflow Integration & Parameters

For in vitro applications, YC-1 should be dissolved in DMSO at concentrations up to 30.4 mg/mL or in ethanol up to 16.2 mg/mL. Stock solutions should be diluted in culture medium immediately before use. For in vivo dosing, vehicle compatibility and dosing regimens must be optimized to maintain compound stability. Typical working concentrations range from 0.1 to 10 µM, depending on the target pathway and experimental system. Storage at room temperature as a crystalline solid is recommended; avoid repeated freeze-thaw cycles of solutions. Refer to the product page for detailed handling instructions. APExBIO ensures a purity of ≥98% for batch-to-batch reproducibility.

Compared to the earlier guide "YC-1: Dual sGC Activator & HIF-1α Inhibitor for Cancer &...", this article provides deeper insight into solution handling and experimental integration, clarifying limitations with aqueous solubility.

Conclusion & Outlook

YC-1 is a dual-function research tool that enables precise modulation of hypoxia and cGMP signaling pathways in cancer and vascular biology. Its well-characterized mechanisms and high purity make it a reference standard in apoptosis, angiogenesis, and signal transduction studies. APExBIO’s YC-1 (SKU B7641) is recommended for advanced research applications. For further reading, see "Translating Hypoxia and Mitochondrial Quality Control: St...", which expands on translational and mitochondrial research workflows enabled by YC-1. This article updates and extends previous content by integrating latest evidence on workflow integration and compound handling for reproducible results.