Biology subjects

Mamet, N.

Publications and source records attributed to Mamet, N..

3 recordsLinked to original sources

bioRxiv2019

Discovery of tumoricidal DNA aptamers by effect-directed in-vitro evolution

Our current model of drug discovery is challenged by the relative ineffectiveness of drugs against highly variable and rapidly evolving diseases and their relatively high incidence of adverse effects due to poor selectivity. Here we describe a robust and reproducible platform which could potentially address these limitations. The platform enables rapid, de-novo discovery of DNA oligonucleotides evolved in-vitro to exert specific biological effects on target cells. Unlike aptamers, which are selected by their ligand binding capacity, this platform is driven directly by therapeutic effect and selectivity towards target vs negative target cells. The process could, therefore, operate without any a-priori knowledge (e.g. mutations, biomarker expression, or known drug resistance) of the target. We report the discovery of DNA oligonucleotides with direct and selective cytotoxicity towards several tumor cell lines as well as primary, patient-derived solid and hematological tumors, some with chemotherapy resistance. Oligonucleotides discovered by this platform exhibited favorable biodistribution in animals, persistence in target tumors up to 48 hours after injection, and safety in human blood. These oligonucleotides showed remarkable efficacy in-vivo as well as ex-vivo in freshly obtained, 3D cultured human tumors resistant to multiple chemotherapies. With further improvement, these findings could lead to a drug discovery model which is target-tailored, mechanism-flexible, and nearly on-demand.

synthetic biology↗

bioRxiv2019

De-novo discovery of tumoricidal aptamers in a DNA sequencing chip

We describe a technique for the rapid ab-initio discovery of target-tailored tumoricidal DNA oligonucleotides inside an Illumina sequencing chip. By sequencing oligonucleotide pools we generate a physical microfluidic map of hundreds of millions of potential oligo clusters, in which every cluster is mapped to a specific set of spatial coordinates. Tumor cells, pre-loaded with a fluorogenic reporter of apoptosis, are then injected into the chip and monitored over time. Apoptotic tumor cells are identified and analyzed across the entire map, automatically revealing the coordinates of oligos that induced this effect. We demonstrate this method by identifying, within just a few hours, new oligos capable of directly and selectively inducing apoptosis in primary human tumor cells. Such a major capability could lead to a new paradigm of personalized cancer therapy.

synthetic biology↗

bioRxiv2018

Simulating the Monty Hall problem in a DNA sequencing machine

The Monty Hall problem is a decision problem with an answer that is surprisingly counter-intuitive yet provably correct. Here we simulate and prove this decision in a high-throughput DNA sequencing machine, using a simple encoding. All possible scenarios are represented by DNA oligonucleotides, and gameplay decisions are implemented by sequencing these oligonucleotides from specific positions, with a single run simulating more than 12,000,000 independent games. This work highlights high-throughput DNA sequencing as a new tool that could extend existing capabilities and enable new encoding schemes for problems in DNA computing.

synthetic biology↗