G007-LK Tankyrase 1/2 Inhibitor: Precise Tool for Wnt/β-catenin Signaling and APC-Mutant Cancer Research

Executive Summary: G007-LK is a potent and selective small-molecule inhibitor of tankyrase 1 and 2 (TNKS1/2) with nanomolar IC₅₀ values (25–46 nM), directly inhibiting auto-poly(ADP ribosyl)ation and downregulating Wnt/β-catenin signaling [Jia et al., 2017]. In APC-mutant colorectal cancer cells, G007-LK induces β-catenin degradation and stabilizes AXIN1/2, suppressing tumor cell proliferation [APExBIO Product Page]. The compound exhibits in vivo anti-tumor efficacy in xenograft models at 20–40 mg/kg, reducing TNKS1/2 and β-catenin protein levels [Jia et al., 2017]. G007-LK is insoluble in water/ethanol but soluble at ≥26.5 mg/mL in DMSO and should be stored at -20°C [APExBIO]. It is widely used for dissecting Wnt/β-catenin and Hippo pathway crosstalk, and for benchmarking tankyrase inhibition in cancer biology research [Related Article].

Biological Rationale

Tankyrases (TNKS1/2) are poly(ADP-ribosyl) polymerases involved in regulating Wnt/β-catenin signaling, telomere maintenance, and cell cycle progression [Jia et al., 2017]. Dysregulation of these enzymes promotes aberrant stabilization of β-catenin, a key oncogenic driver in APC-mutant colorectal cancer and hepatocellular carcinoma [Related Article]. In normal physiology, tankyrases mediate post-translational modification (PARsylation) of AXIN1/2, marking them for proteasomal degradation. This reduces the β-catenin destruction complex, raising cytosolic and nuclear β-catenin levels. Inhibition of TNKS1/2 restores AXIN1/2 stability and increases β-catenin degradation, providing a tractable route to target Wnt-driven tumor growth [Compare: This article details precise workflow integration and molecular benchmarks, while previous reviews summarize broader context].

Mechanism of Action of G007-LK tankyrase 1/2 inhibitor

G007-LK (C₂₅H₁₆ClN₇O₃S, MW 529.96) is a selective inhibitor of tankyrase 1/2, binding the catalytic PARP domain and blocking auto-poly(ADP ribosyl)ation with IC₅₀ values of 46 nM (TNKS1) and 25 nM (TNKS2) [APExBIO]. In Wnt3a-induced HEK 293 cells, it inhibits the Wnt reporter ST-Luc with an IC₅₀ of 0.05 μM. In APC-mutant colorectal cancer lines (e.g., SW480), G007-LK induces formation of degradasomes containing phosphorylated β-catenin, β-TrCP, and ubiquitin, lowering both cytosolic and nuclear β-catenin [Jia et al., 2017]. AXIN1/2 is stabilized, supporting destruction complex assembly and fostering β-catenin degradation. In parallel, G007-LK modulates Hippo pathway effectors, reducing YAP protein levels and upregulating AMOTL1/2, which are negative regulators of YAP activity [This article extends mechanistic detail on Hippo pathway crosstalk beyond prior reviews].

Evidence & Benchmarks

• G007-LK inhibits auto-PARsylation of TNKS1 (IC₅₀: 46 nM) and TNKS2 (IC₅₀: 25 nM) in biochemical assays (APExBIO product page).
• In Wnt3a-induced HEK 293 cells, G007-LK inhibits Wnt/β-catenin signaling as measured by ST-Luciferase reporter (IC₅₀: 0.05 μM) (APExBIO).
• In APC-mutant colorectal cancer lines (e.g., SW480), G007-LK induces β-catenin degradasomes, leading to reduced cytosolic/nuclear β-catenin (Jia et al., 2017).
• G007-LK stabilizes AXIN1/2 protein levels and reduces TNKS1/2 and β-catenin in tumor tissues in COLO-320DM xenograft mouse models (20–40 mg/kg) (Jia et al., 2017).
• In hepatocellular carcinoma, G007-LK suppresses cell proliferation and downregulates YAP/TEAD pathway, upregulating AMOTL1/2 (Jia et al., 2017).
• Synergistic suppression of tumor cell proliferation observed with G007-LK plus MEK or AKT inhibitors (Jia et al., 2017).

Applications, Limits & Misconceptions

G007-LK is applied in research on Wnt/β-catenin signaling, colorectal and hepatocellular carcinoma, tankyrase biology, cell cycle progression, and β-catenin degradation. It is particularly valuable in models featuring APC mutations, such as SW480 and COLO-320DM cell lines. Researchers leverage G007-LK to benchmark tankyrase inhibition, validate AXIN stabilization, and probe Hippo pathway crosstalk.

Common Pitfalls or Misconceptions

• G007-LK is not suitable for direct clinical use; it is strictly for preclinical and basic research applications (APExBIO).
• It does not inhibit all PARP family members; specificity is for TNKS1/2, not classic PARP1/2 (Jia et al., 2017).
• Solubility is limited to DMSO (≥26.5 mg/mL); it is insoluble in water or ethanol, which may restrict formulation options (APExBIO).
• Loss of activity may occur if solutions are stored long-term or at temperatures above -20°C (APExBIO).
• In vivo efficacy is so far limited to xenograft models; human pharmacokinetics and toxicity profiles remain uncharacterized (Jia et al., 2017).

Workflow Integration & Parameters

G007-LK is provided as a solid (SKU: B5830) by APExBIO. Dissolve in DMSO to ≥26.5 mg/mL for in vitro assays. Use fresh solutions when possible. For in vivo xenograft studies, dosing at 20–40 mg/kg has demonstrated efficacy in mouse models. Recommended storage is at -20°C; avoid freeze-thaw cycles. For Wnt signaling assays, G007-LK is typically applied at 0.01–1 μM. For mechanistic studies on β-catenin or Hippo pathway, employ validated cell lines (e.g., SW480, HEK 293) and measure target protein levels by Western blot or reporter assays. For further workflow details and troubleshooting, see this advanced workflow article (which focuses on troubleshooting and protocol optimization, whereas the current article emphasizes quantitative benchmarks and application boundaries).

Conclusion & Outlook

G007-LK is a gold-standard, specific tankyrase 1/2 inhibitor for Wnt/β-catenin signaling research, supporting advanced APC mutation colorectal cancer studies. Its validated molecular benchmarks, strong selectivity, and reproducible performance make it an essential tool for dissecting tankyrase-mediated signaling and β-catenin turnover. Ongoing research explores further applications, including Hippo pathway modulation and combination therapy paradigms. For detailed product specifications and ordering information, visit the G007-LK tankyrase 1/2 inhibitor product page from APExBIO.