Design, Synthesis, and Evaluation of Pyrazolopyridine Derivatives as Novel Calreticulin (CALR) Ligands That Inhibit
Jiaguo Lu1, Anqi Yin1, Shenpeng Tan1
1School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Basic Science Research Center Base (Pharmaceutical Science), Yantai University, Yantai 264005, China.
Abstract:
Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer, posing significant therapeutic challenges due to the lack of effective targets. Elevating intracellular calcium levels is a promising strategy in cancer therapy, and highly expressed calreticulin (CALR) in tumors has emerged as a potential target for inducing calcium overload. However, few studies on CALR ligands have been reported. Herein, we designed, synthesized, and evaluated pyrazolopyridine derivatives as potential CALR ligands. Among them, the leading compound 2a was identified as a high binding affinity ligand (Kd = 2.6 μM) with potent antitumor activity (IC50 = 0.1 μM). Mechanistic studies demonstrated that 2a could interact with CALR, inducing calcium overload and leading to apoptosis in TNBC cells. Further in vivo pharmacodynamic evaluations confirmed the safety and antitumor activity of 2a. In conclusion, our findings developed a novel CALR ligand and provided a new anti-TNBC strategy via inducing calcium dysregulation.
Insights
Researchers developed a novel pyrazolopyridine compound that targets calreticulin (CALR) to induce calcium overload, offering a new therapeutic strategy against aggressive triple-negative breast cancer (TNBC). This compound shows potent antitumor activity and safety in preclinical evaluations.
Area of Science:
- Oncology
- Molecular Biology
- Medicinal Chemistry
Background:
- Triple-negative breast cancer (TNBC) is an aggressive subtype with limited targeted therapies.
- Elevating intracellular calcium is a potential anti-cancer strategy.
- Calreticulin (CALR) is a potential target for inducing calcium overload, but CALR ligands are scarce.
Purpose of the Study:
- To design, synthesize, and evaluate pyrazolopyridine derivatives as novel CALR ligands.
- To identify a potent CALR ligand with anti-TNBC activity.
- To elucidate the mechanism of action for anti-TNBC therapy.
Main Methods:
- Chemical synthesis of pyrazolopyridine derivatives.
- Binding affinity assays to evaluate CALR ligand interactions (Kd).
- In vitro cytotoxicity assays (IC50) and apoptosis studies in TNBC cells.
- In vivo pharmacodynamic evaluations in preclinical models.
Main Results:
- Compound 2a demonstrated high binding affinity to CALR (Kd = 2.6 μM).
- Compound 2a exhibited potent antitumor activity against TNBC cells (IC50 = 0.1 μM).
- Mechanistic studies confirmed CALR interaction, calcium overload, and apoptosis induction in TNBC cells.
- In vivo studies validated the safety and efficacy of compound 2a.
Conclusions:
- A novel pyrazolopyridine derivative (2a) was identified as a high-affinity CALR ligand.
- Compound 2a effectively induces calcium dysregulation and apoptosis in TNBC cells.
- This study presents a promising new therapeutic strategy for TNBC by targeting CALR-mediated calcium overload.
