A genome-wide CRISPR screen reveals cancer-specific regulators of hyaluronan binding and cellular invasion

Metastatic spread of cancer cells is driven by binding between the cell-surface receptor CD44 and hyaluronan (HA) in the extracellular matrix. The specific oncogenes that drive increased CD44-HA binding in cancer remain poorly defined. Using a fluorescently labeled hyaluronan probe, we performed a genome-wide CRISPR screen to identify genes whose knockdown disrupts HA binding in breast cancer cells. We subsequently developed a bioinformatic analysis pipeline that enabled stratification and prioritization of cancer-specific regulators. This work provides a first-in-class resource for the identification of druggable targets to inhibit HA binding. We further validate RAB4A, a top hit from our screen, as a novel regulator of this process. Mechanistically, RAB4A KO dramatically reduces CD44 expression and inhibits the invasion of breast cancer cells through HA-rich matrices. This study validates a novel strategy for identifying regulators of cancer cell invasion and identifies immediate actionable targets for anti-metastatic therapy.