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Quassinoid analogs with enhanced efficacy for treatment of hematologic malignancies target the PI3Kγ isoform
Yonggang Pei1, Nicky Hwang2, Fengchao Lang1
1Departments of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, and the Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
Abstract:
Development of novel PI3K inhibitors is an important strategy to overcome their resistance and poor tolerability in clinical trials. The quassinoid family member Brusatol shows specific inhibitory activity against hematologic malignancies. However, the mechanism of its anti-cancer activity is unknown. We investigated the anti-cancer activity of Brusatol on multiple hematologic malignancies derived cell lines. The results demonstrated that the PI3Kγ isoform was identified as a direct target of Brusatol, and inhibition was dramatically reduced on cells with lower PI3Kγ levels. Novel synthetic analogs were also developed and tested in vitro and in vivo. They shared comparable or superior potency in their ability to inhibit malignant hematologic cell lines, and in a xenograft transplant mouse model. One unique analog had minimal toxicity to normal human cells and in a mouse model. These new analogs have enhanced potential for development as a new class of PI3K inhibitors for treatment of hematologic malignancies.
Insights
Brusatol, a quassinoid, targets PI3Kγ in hematologic cancers. Novel analogs show potent anti-cancer activity with reduced toxicity, offering a new PI3K inhibitor class for treatment.
Area of Science:
- Oncology
- Pharmacology
- Molecular Biology
Background:
- Novel phosphoinositide 3-kinase (PI3K) inhibitors are crucial for overcoming resistance and poor tolerability in clinical settings.
- Brusatol, a quassinoid, exhibits specific inhibitory activity against hematologic malignancies, but its anti-cancer mechanism remains unclear.
Purpose of the Study:
- To investigate the anti-cancer activity and mechanism of Brusatol in hematologic malignancies.
- To develop and evaluate novel synthetic analogs of Brusatol as potential PI3K inhibitors.
Main Methods:
- Screening Brusatol activity across various hematologic malignancy cell lines.
- Identifying direct molecular targets of Brusatol using cellular assays.
- Synthesizing and testing novel Brusatol analogs in vitro and in vivo.
- Evaluating toxicity in normal human cells and mouse models.
Main Results:
- The PI3Kγ isoform was identified as a direct target of Brusatol.
- Brusatol's inhibitory effect was significantly reduced in cells with lower PI3Kγ expression.
- Novel synthetic analogs demonstrated comparable or superior potency against malignant hematologic cell lines.
- One analog exhibited minimal toxicity to normal cells and in vivo models.
Conclusions:
- Brusatol's anti-cancer activity in hematologic malignancies is mediated through direct inhibition of the PI3Kγ isoform.
- Developed Brusatol analogs represent a promising new class of PI3K inhibitors.
- These analogs possess enhanced potential for therapeutic development in hematologic malignancies with improved safety profiles.
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