Epigenome-Wide CRISPR-Cas9-Based Knockout Screens on Chemoresistant Cells

Area of Science:

• Cancer Biology
• Epigenetics
• Genomics

Background:

• Chemotherapy resistance is a significant obstacle in cancer treatment, often involving epigenetic alterations.
• Triple-negative breast cancer (TNBC) exhibits resistance to paclitaxel, a common chemotherapeutic agent.
• Epigenetic regulators play a crucial role in the adaptive mechanisms cancer cells use to evade chemotherapy.

Purpose of the Study:

• To develop and validate a robust methodological framework for identifying epigenetic regulators of paclitaxel resistance in TNBC.
• To enable the application of epigenome-focused CRISPR screens in chemoresistant cancer models.
• To discover novel epigenetic targets that contribute to acquired chemotherapy resistance.

Main Methods:

• Generation of chemoresistant TNBC cell lines using a stepwise dose-escalation protocol.
• Development of high-efficiency lentiviral transduction and selection methods for multidrug-resistant (MDR) cells.
• Application of an epigenome-focused knockout library (EPIKOL) with CRISPR-Cas9 for loss-of-function screening.

Main Results:

• Successful implementation of a protocol for high-efficiency lentiviral transduction and selection in chemoresistant TNBC cells.
• Identification of novel epigenetic regulators contributing to acquired paclitaxel resistance through an epigenome-wide CRISPR screen.
• Demonstration of the protocol's robustness for investigating epigenetic mechanisms of drug resistance.

Conclusions:

• The developed protocol facilitates the systematic identification of epigenetic regulators involved in chemotherapy resistance.
• This approach provides a powerful tool for discovering new therapeutic targets to overcome paclitaxel resistance in TNBC.
• The findings highlight the critical role of epigenetics in cancer drug adaptation and resistance.