G007-LK Tankyrase 1/2 Inhibitor: Precision Tool for Wnt/β-Catenin Signaling Research

Executive Summary: G007-LK is a small molecule that selectively inhibits tankyrase 1 (TNKS1) and tankyrase 2 (TNKS2) with IC₅₀ values of 46 nM and 25 nM, respectively, thereby blocking poly(ADP-ribosyl)ation and attenuating Wnt/β-catenin signaling [APExBIO]. The compound induces β-catenin degradation via stabilization of AXIN1/2 in APC-mutant colorectal cancer and hepatocellular carcinoma models (Jia et al., 2017). G007-LK demonstrates in vivo antitumor efficacy, reducing tumor growth and β-catenin levels in xenograft mouse models. The inhibitor is widely used to study Wnt and Hippo pathway crosstalk, providing high signal specificity and reproducibility in pathway inhibition assays. G007-LK is insoluble in water/ethanol, but dissolves at ≥26.5 mg/mL in DMSO and is stable as a solid at −20°C [APExBIO].

Biological Rationale

Tankyrases (TNKS1 and TNKS2) are poly(ADP-ribose) polymerases that regulate Wnt/β-catenin signaling, telomere maintenance, and cellular proliferation (Jia et al., 2017). Abnormal activation of Wnt/β-catenin signaling is implicated in colorectal cancer, hepatocellular carcinoma, and other malignancies. Tankyrase activity promotes β-catenin stability by targeting AXIN1/2 for degradation. Inhibition of tankyrases thus stabilizes AXIN1/2, facilitating β-catenin destruction. G007-LK is engineered to exploit this vulnerability, enabling precise mechanistic dissection of Wnt pathway regulation in APC-mutant and wild-type cell contexts [Related: Mouse IFN-A]. In contrast to some tankyrase inhibitors, G007-LK offers nanomolar potency and high selectivity, minimizing off-target poly(ADP-ribosyl)ation effects.

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

• G007-LK binds to the catalytic PARP domain of TNKS1 and TNKS2, inhibiting their auto-poly(ADP-ribosyl)ation activity with IC₅₀ values of 46 nM and 25 nM, respectively (APExBIO).
• This inhibition stabilizes AXIN1/2, a scaffold protein critical for the β-catenin destruction complex.
• Stabilized AXIN1/2 promotes polyubiquitylation and proteasomal degradation of β-catenin, lowering cytosolic and nuclear β-catenin levels.
• In APC-mutant colorectal cancer cells (e.g., SW480), G007-LK induces the assembly of degradasomes containing phosphorylated β-catenin, β-TrCP, and ubiquitin, accelerating β-catenin turnover.
• In Wnt3a-induced HEK293 cells, G007-LK inhibits Wnt signaling reporter ST-Luc with an IC₅₀ of 0.05 μM, indicating potent pathway suppression.
• In hepatocellular carcinoma, G007-LK downregulates the oncogenic YAP/TAZ transcriptional coactivators by stabilizing AMOTL1/2, further suppressing proliferation (Jia et al., 2017).

Evidence & Benchmarks

• G007-LK inhibits TNKS1 and TNKS2 enzymatic activity with IC₅₀ values of 46 nM and 25 nM, respectively, as measured in biochemical assays (APExBIO).
• In Wnt3a-induced HEK293 cells, G007-LK suppresses the ST-Luc reporter with an IC₅₀ of 0.05 μM (APExBIO).
• In APC-mutant SW480 colorectal cancer cells, G007-LK induces formation of degradasomes containing phosphorylated β-catenin, β-TrCP, and ubiquitin, leading to reduced cytosolic/nuclear β-catenin levels (APExBIO).
• In vivo, G007-LK reduces tumor growth and β-catenin protein levels, while stabilizing AXIN1/2 in COLO-320DM xenograft mouse models (APExBIO).
• In hepatocellular carcinoma models, G007-LK suppresses cell proliferation and decreases YAP protein levels via AMOTL1/2 stabilization (Jia et al., 2017).
• Tankyrase inhibition by G007-LK synergizes with MEK and AKT inhibitors to further suppress proliferation in HCC cell lines (Jia et al., 2017).

This article extends the overview found in G007-LK: Specific Tankyrase Inhibitor for Wnt Signaling Research by detailing benchmarked IC₅₀ values, in vivo efficacy, and cross-pathway impacts. For advanced mechanistic insights, see Unraveling Tankyrase Inhibition for Precision Wnt Pathway Targeting, which this article updates with the latest in vivo and cell-based findings. For a discussion of workflow optimization and comparative troubleshooting, A Next-Generation Tankyrase Inhibitor Redefining Signal Transduction provides complementary perspectives.

Applications, Limits & Misconceptions

G007-LK is primarily used to study:

• Wnt/β-catenin signaling pathway inhibition in cancer biology.
• APC mutation colorectal cancer research and β-catenin degradation induction.
• AXIN1/2 stabilization and Hippo pathway modulation in hepatocellular carcinoma.
• Preclinical antitumor efficacy in xenograft models.

Common Pitfalls or Misconceptions

• G007-LK is not effective in models lacking tankyrase-dependent Wnt signaling (e.g., β-catenin mutations downstream of AXIN destruction).
• It does not directly inhibit other PARP family members or general poly(ADP-ribosyl)ation unrelated to tankyrase.
• Solubility is limited to DMSO; use in aqueous or ethanol-only systems is not recommended.
• Prolonged solution storage reduces activity; always prepare fresh DMSO stocks and avoid repeated freeze-thaw cycles.
• G007-LK may not be suitable for clinical use; it is strictly for research purposes and not validated for human therapy.

Workflow Integration & Parameters

• G007-LK is supplied as a solid (SKU: B5830) by APExBIO. Store at −20°C, protected from light and moisture (APExBIO).
• Dissolve at ≥26.5 mg/mL in DMSO. For optimal solubility, warm to 37°C or use an ultrasonic bath.
• Avoid long-term storage of DMSO solutions; prepare fresh aliquots for each experiment.
• Typical working concentrations: 10–100 nM for cell-based studies, up to 1 μM in select reporter assays.
• Validated in both 2D and 3D cell culture, as well as in vivo xenograft studies.
• Combine with pathway-specific reporter systems (e.g., ST-Luc for Wnt, TEAD-Luc for Hippo) to monitor target engagement and pathway suppression.

Conclusion & Outlook

G007-LK tankyrase 1/2 inhibitor provides researchers with a highly selective, nanomolar-potency tool for dissecting Wnt/β-catenin and Hippo pathway regulation in cancer models. Its robust performance in APC-mutant colorectal and hepatocellular carcinoma cells, as well as validated in vivo antitumor effects, make it a gold standard for pathway inhibition studies. As new research expands the role of tankyrase in disease, G007-LK is positioned to facilitate discovery and preclinical validation of novel therapeutic strategies. For more information or to purchase, refer to the official APExBIO G007-LK tankyrase 1/2 inhibitor product page.