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Biology subjects

Wilson, L. L.

Publications and source records attributed to Wilson, L. L..

3 recordsLinked to original sources

Functional modules predict cancer-relevant genetic interactions in mammalian cells

Genetic interactions can reveal gene function and identify disease-relevant synthetic lethals, but resource-intensive screening in human cells constrains experimental scope and limits our understanding of how generalizable sparse hits are. Here, we leverage principles from yeast genetic networks to identify human gene modules involved in receptor tyrosine kinase signaling and DNA damage response that are predicted to be enriched for genetic interactions, then use our enCas12a-based In4mer combinatorial knockout platform to efficiently screen these modules across diverse cancer cell lines. We identify hundreds of unreported synthetic lethals, including a dense network within the protein N-linked glycosylation machinery that shows both evolutionary conservation and network rewiring, and we confirm that interactions discovered in 2D cell culture are maintained in more physiologically relevant models. Critically, a meta-analysis within and between screens highlights sources of variation in published results, reveals the potential for false positives in screens with many essential genes, and demonstrates the need to move beyond DDR for actionable synthetic lethalities.

systems biology↗

Combined genome-scale fitness and paralog synthetic lethality screens with just 44k clones: the IN4MER CRISPR/Cas12a multiplex knockout platform

Genetic interactions mediate the emergence of phenotype from genotype, but initial technologies for combinatorial genetic perturbation in mammalian cells suffer from inefficiency and are challenging to scale. Recent focus on paralog synthetic lethality in cancer cells offers an opportunity to evaluate different approaches and improve on the state of the art. Here we report a meta-analysis of CRISPR genetic interactions screens, identifying a candidate set of background-independent paralog synthetic lethals, and find that the Cas12a platform provides superior sensitivity and assay replicability. We demonstrate that Cas12a can independently target up to four genes from a single guide array, and we build on this knowledge by constructing a genome-scale library that expresses arrays of four guides per clone, a platform we call in4mer. Our genome-scale human library, with only 49k clones, is substantially smaller than a typical CRISPR/Cas9 monogenic library while also targeting more than four thousand paralog pairs, triples, and quads. Proof of concept screens in four cell lines demonstrate discrimination of core and context-dependent essential genes similar to that of state-of-the-art CRISPR/Cas9 libraries, as well as detection of synthetic lethal and masking/buffering genetic interactions between paralogs of various family sizes, a capability not offered by any extant library. Importantly, the in4mer platform offers a fivefold reduction in the number of clones required to assay genetic interactions, dramatically improving the cost and effort required for these studies.

systems biology↗

A novel mitragynine analog with low efficacy mu-opioid receptor agonism displays antinociception with attenuated adverse effects

Dried kratom leaves are anecdotally used for the treatment of pain, opioid dependence, and alcohol use disorder. We have previously shown that kratoms natural products (mitragynine) and semi-synthetic analogs (7-hydroxy mitragynine (7OH) and mitragynine pseudoindoxyl) are mu opioid receptor (MOR) agonists that show minimal {beta}-arrestin2 recruitment. To further investigate the structure activity relationships of G-protein potency, efficacy, and {beta}-arrestin2 recruitment, we diversified the mitragynine/7OH templates at the C9, -10 and -12 positions of the aromatic ring of the indole moiety. Three lead C9 analogs, synthesized by swapping the 9-methoxy group with varied substituents, namely phenyl (SC11), methyl (SC12), 3-furanyl (SC13), were further characterized using a panel of in vitro and ex vivo electrophysiology assays. All three compounds were partial agonists with lower efficacy than both DAMGO and morphine in heterologous G-protein assays and synaptic physiology. SC11-13 also showed lower recruitment of both {beta}-arrestin subtypes compared to DAMGO, and in assays with limited MOR receptor reserve, the G-protein efficacy of SC11, SC12 and SC13 was comparable to buprenorphine. In mouse models, at equianalgesic doses SC13 showed MOR-dependent analgesia with potency similar to morphine without respiratory depression, hyperlocomotion, constipation, or place conditioning. Taken together, these results suggest that MOR agonists with a G-protein efficacy profile similar to buprenorphine can be developed into opioids that are effective analgesics with greatly reduced liabilities.

pharmacology and toxicology↗