A CRISPRi/a screening platform to study cellular nutrient transport in diverse microenvironments

Area of Science:

• Cancer Biology
• Molecular Biology
• Metabolic Pathways

Background:

• Targeting nutrient import is a promising cancer therapy strategy.
• Identifying specific nutrient transporters crucial for cancer cell survival and proliferation is challenging.
• The tumor microenvironment significantly influences cancer cell metabolism and transporter function.

Purpose of the Study:

• To develop and apply a CRISPR screening platform for systematically identifying essential nutrient transporters in cancer.
• To characterize the role of amino acid transporters in leukemia cells and their dependence on microenvironment.
• To uncover novel nutrient transporter functions, including those involved in ferroptosis and tumor growth.

Main Methods:

• CRISPR interference/activation screening platform to interrogate nutrient transporter function.
• Application of the platform to leukemia cells and subcutaneous tumor models.
• Analysis of nutrient flux, cell proliferation, and ferroptosis under varying environmental conditions.

Main Results:

• Identified critical amino acid transporters in leukemia, demonstrating high bidirectional flux influenced by microenvironment.
• Discovered a role for serotonin uptake in preventing ferroptosis in cystine-starved cells.
• Found that glucose and amino acid availability can limit proliferation in subcutaneous tumors, identifying essential transporters for tumor growth.

Conclusions:

• Established a robust framework for systematic identification and functional characterization of cellular nutrient transporters.
• Highlighted the dynamic and microenvironment-dependent nature of nutrient transport in cancer.
• Provided insights into novel therapeutic targets and strategies for modulating cancer metabolism.