CRISPR-Cas9 Based Whole Genome Screen Reveals Genetic Modulators of Chemoresistance in Leukemia
Presenter Status
Graduate Student
Abstract Type
Basic Research
Primary Mentor or Principal Investigator
Dr. John Perry
Presentation Type
Poster
Start Date
20-5-2026 12:00 PM
End Date
20-5-2026 1:00 PM
Abstract Text
Background: Treatment for pediatric leukemia involves use of high dose chemotherapeutic agents which result in severe side effects including cardiotoxicity and development of secondary cancers. Nearly 20% of childhood cancer patients do not survive long-term, emphasizing the need for new therapies that target chemoresistance without major side effects. Doxorubicin (DXR), a commonly used chemotherapy drug often administered clinically at high dose, selectively targets chemo-resistant leukemia stem cells (LSC) at low doses without being toxic to healthy cells.
Objectives/Goal: The goal of the study was to identify genetic modulators that cooperate with low dose DXR to enhance immunogenicity of leukemia cells along with targets involved in chemoresistance. The identification of genetic targets can then be used to develop targeted therapies in combination with low dose DXR
Methods/Design: We employed a CRISPR-Cas9 based screen to identify gene targets that confer drug resistance or sensitivity. We performed a genome wide repression (CRISPRi) screen in a chronic myelogenous leukemia cell line (K562) treated with both low and high dose DXR. The human Dolcetto CRISPR inhibition sgRNA library targets 18,901 genes with 3 sgRNA per gene. Genomic DNA was isolated post-treatment, sgRNA library was amplified and sequenced. Using MAGeCK-MLE based analysis top hits were identified.
Results: Key findings included ZMYND8, a chromatin reader and NLRP2, in the cytotoxic dose. Validation studies show that overexpressing ZMYND8 in leukemia cells reduces the expression of immune checkpoint PD-L1 making them susceptible to immunogenic cell death (ICD). However, the CRISPR screen also identified several gene targets at the lower doses including HDAC11, COLEC11, MSX1, PRKDC, and IKZF5. In addition, HDAC11i in K562 increased the expression of Calreticulin (CRT), an ICD marker, when treated with low dose DXR, highlighting HDAC11 as a promising target to enhance low-dose DXR efficacy and reduce overall toxicity.
Conclusions: These results confirm the potential of the CRISPR-Cas9 based screen is a powerful tool in identifying novel genetic modulators of chemoresistance in leukemia providing promising targets for less toxic therapeutic strategies.
CRISPR-Cas9 Based Whole Genome Screen Reveals Genetic Modulators of Chemoresistance in Leukemia
Background: Treatment for pediatric leukemia involves use of high dose chemotherapeutic agents which result in severe side effects including cardiotoxicity and development of secondary cancers. Nearly 20% of childhood cancer patients do not survive long-term, emphasizing the need for new therapies that target chemoresistance without major side effects. Doxorubicin (DXR), a commonly used chemotherapy drug often administered clinically at high dose, selectively targets chemo-resistant leukemia stem cells (LSC) at low doses without being toxic to healthy cells.
Objectives/Goal: The goal of the study was to identify genetic modulators that cooperate with low dose DXR to enhance immunogenicity of leukemia cells along with targets involved in chemoresistance. The identification of genetic targets can then be used to develop targeted therapies in combination with low dose DXR
Methods/Design: We employed a CRISPR-Cas9 based screen to identify gene targets that confer drug resistance or sensitivity. We performed a genome wide repression (CRISPRi) screen in a chronic myelogenous leukemia cell line (K562) treated with both low and high dose DXR. The human Dolcetto CRISPR inhibition sgRNA library targets 18,901 genes with 3 sgRNA per gene. Genomic DNA was isolated post-treatment, sgRNA library was amplified and sequenced. Using MAGeCK-MLE based analysis top hits were identified.
Results: Key findings included ZMYND8, a chromatin reader and NLRP2, in the cytotoxic dose. Validation studies show that overexpressing ZMYND8 in leukemia cells reduces the expression of immune checkpoint PD-L1 making them susceptible to immunogenic cell death (ICD). However, the CRISPR screen also identified several gene targets at the lower doses including HDAC11, COLEC11, MSX1, PRKDC, and IKZF5. In addition, HDAC11i in K562 increased the expression of Calreticulin (CRT), an ICD marker, when treated with low dose DXR, highlighting HDAC11 as a promising target to enhance low-dose DXR efficacy and reduce overall toxicity.
Conclusions: These results confirm the potential of the CRISPR-Cas9 based screen is a powerful tool in identifying novel genetic modulators of chemoresistance in leukemia providing promising targets for less toxic therapeutic strategies.
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Poster Board Number: 34