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Yockell-Lelievre, J.

Publications and source records attributed to Yockell-Lelievre, J..

2 recordsLinked to original sources

TSC2-deficiency potentiates a catabolic signaling switch that differentiates neural and neural crest lineage development and progressive disease manifestations

Lymphangioleiomyomatosis (LAM) is a rare lung disease marked by cystic destruction caused by invasive LAM cells harboring loss-of-function mutations in TSC2 that exhibit dysregulated mTORC1 signaling. Rapamycin, the only approved treatment, is not curative. Therapeutic discovery has been limited by inadequate cell and animal models due to the unknown LAM cell of origin. We report a novel TSC2--/-- human pluripotent stem cell (hPSC)-derived neural crest cell (NCC) model, which replicates key LAM features. Leveraging this model, temporal RNA sequencing and genome-wide CRISPR knockout screens identified synthetic lethal genes including TWIST1 and SUN4. Antisense oligonucleotides (ASOs) targeting TWIST1 and SUN4 demonstrated selective TSC2 mutant NCC cytotoxicity and inhibited invasion. Using a "test-withdraw-monitor" clinical trial paradigm, TWIST1 and SUN4 ASOs profoundly suppressed tumor viability in a Tsc2--/-- mouse allograft model and eradicated 40% of tumors, outperforming standard of care rapamycin and highlighting their promise as novel cytoablative LAM therapeutics.

cancer biology

Transcriptomically-guided mesendoderm induction of human pluripotent stem cells using a systematically defined culture scheme

Human pluripotent stem cells (hPSCs) are an essential cell source in tissue engineering, studies of development, and disease modeling. Efficient, broadly amenable protocols for rapid lineage induction of hPSCs are of great interest in the stem cell biology field. We describe a simple, robust method for differentiation of hPSCs into mesendoderm in defined conditions utilizing single-cell seeding (SCS) and BMP4 and Activin A (BA) treatment. Gene sets and gene ontology terms related to mesoderm and endoderm differentiation were enriched after 48 hours of BA treatment. BA treatment was readily incorporated into existing protocols for chondrogenic and endothelial progenitor cell differentiation. After prolonged differentiation in vitro or in vivo, BA pre-treatment resulted in higher mesoderm and endoderm levels at the expense of ectoderm formation. These data demonstrate that SCS with BA treatment is a powerful method for induction of mesendoderm that can be integrated into protocols for mesoderm and endoderm differentiation.

bioengineering