Stratified Medicine Paediatrics: Cell free DNA and serial tumour sequencing identifies subtype specific cancer evolution and epigenetic states.

We profiled a large heterogenous cohort of matched diagnostic-relapse tumour tissue and paired plasma-derived cell free DNA (cfDNA) from patients with relapsed and progressive solid tumours of childhood. Tissue and cfDNA sequencing results were concordant, with a wider spectrum of mutant alleles and higher degree of intra-tumour heterogeneity captured by the latter, if sufficient circulating tumour-derived DNA (ctDNA) was present. Serial tumour sequencing identified putative drivers of relapse, with alterations in epigenetic drivers being a common feature.

Circulating tumour DNA sequencing to determine therapeutic response and identify tumour heterogeneity in patients with paediatric solid tumours.

Objective: Clinical diagnostic sequencing of circulating tumour DNA (ctDNA) is well advanced for adult patients, but application to paediatric cancer patients lags behind.

Methods: To address this, we have developed a clinically relevant (67 gene) NGS capture panel and accompanying workflow that enables sensitive and reliable detection of low-frequency genetic variants in cell-free DNA (cfDNA) from children with solid tumours. We combined gene panel sequencing with low pass whole-genome sequencing of the same library to inform on genome-wide copy number changes in the blood.

Engineering and medical applications of diatoms.

Biologists, and diatomists in particular, have long studied the properties of single-cell algae, and engineers are just discovering how to exploit features unique to these organisms. Their uniform nanopore structure, microchannels, chemical inertness, and silica microcrystal structure suggest many nanoscale applications. This paper proposes three potential research initiatives taking advantage of diatom morphology and mechanical and chemical properties: (1) embedding diatom frustules in a metal-film membrane; (2) magnetizing frustules for pinpoint drug delivery; and (3) producing silica nanopowders from frustules.