Overcoming multidrug resistance by knockout of ABCB1 gene using CRISPR/Cas9 system in SW620/Ad300 colorectal cancer...

Area of Science:

• Oncology
• Molecular Biology
• Gene Editing

Background:

• Multidrug resistance (MDR) is a significant challenge in colorectal cancer chemotherapy.
• Upregulated ATP-binding cassette (ABC) transporters, particularly ABCB1/P-glycoprotein, reduce intracellular drug levels, contributing to MDR.
• Targeting ABCB1 is crucial for overcoming chemotherapy failure in colorectal cancer.

Purpose of the Study:

• To investigate the efficacy of the CRISPR/Cas9 system in targeting and knocking out the ABCB1 gene in multidrug-resistant colorectal cancer cells (SW620/Ad300).
• To evaluate the impact of ABCB1 gene knockout on drug accumulation, efflux, and chemosensitivity in MDR colorectal cancer models.

Main Methods:

• Utilized the CRISPR/Cas9 gene editing system to achieve stable knockout of the ABCB1 gene in SW620/Ad300 cells.
• Assessed intracellular accumulation of [3H]-paclitaxel and drug efflux activity.
• Employed a 3D multicellular tumor spheroid model to evaluate tumor growth and chemosensitivity.

Main Results:

• Achieved stable knockout of the ABCB1 gene in MDR colorectal cancer cells using CRISPR/Cas9.
• Observed reversal of MDR, increased intracellular paclitaxel accumulation, and decreased drug efflux post-ABCB1 knockout.
• Demonstrated that ABCB1 deficiency restrained tumor spheroid growth and restored paclitaxel sensitivity in MDR spheroids.

Conclusions:

• The CRISPR/Cas9 system effectively targets and knocks out the ABCB1 gene in MDR colorectal cancer cells.
• ABCB1 gene knockout can overcome ABCB1-mediated multidrug resistance in colorectal cancer.
• This approach holds potential for improving chemotherapy outcomes in colorectal cancer patients with MDR.