Bone morphogenetic protein (BMP) signaling determines neuroblastoma cell fate and sensitivity to retinoic acid [RNA-seq]
Retinoic acid (RA) is a standard-of-care neuroblastoma drug thought to act primarily via differentiation. However, this has never been conclusively demonstrated in vivo. Curiously, RA has little effect shrinking primary human tumors when applied in upfront treatment but can eliminate neuroblastoma cells from the bone marrow during consolidation therapy—a discrepancy that has never been explained. To investigate this, we treated a large cohort of neuroblastoma cell lines with RA and observed that the most RA-sensitive cells tended to undergo apoptosis or senescence, rather than differentiation. We conducted genome-wide CRISPR knockout screens under RA treatment, which identified BMP signaling as controlling the apoptosis/senescence vs differentiation cell fate decision and RA's overall potency. We then conducted integrative analysis of high throughput ChIP-seq and RNA-seq data, which indicates that downstream BMP and RA transcription factors cooperate to determine cell fate, following exposure to RA. Overall design: RNA-seq was performed on CHP-134 cell lines treated with DMSO (control) and ATRA for durations of 1 day, 3 days, and 6 days. We first implanted our hypersensitive CHP-134 cells in mice, then treated them with a pharmacologically relevant dosage of 13-cis RA. Then we performed RNA-seq on our untreated-control and RA-treated xenograft tumors.