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Biology subjects

Hodder, A.

Publications and source records attributed to Hodder, A..

2 recordsLinked to original sources

Extensive and differential platinum chemotherapy mutagenesis in children

Childhood cancer survivors often develop long-term adverse effects, which may be caused by direct mutagenesis of cytotoxic agents. Some of these agents generate distinctive DNA imprints (mutational signatures), as exemplified by platinum chemotherapeutics. Here, we examined chemotherapy mutagenesis in paediatric tissues by deploying a duplex sequencing method (NanoSeq), which enables mutation calling from single DNA molecules. We surveyed whole genomes of paediatric liver, blood and other tissues, obtained from surgical resections and at post-mortem. Platinum signatures pervaded all tissues extensively, elevating mutation burdens of paediatric tissues to levels seen in adults. Remarkably, we found a tissue-specific mutational signature in the liver. We examined the functional potential of mutations by gene focused NanoSeq, which revealed that platinum agents cause a vast repertoire of cancer causing variants across normal tissues, such as leukaemogenic mutations in blood. This finding may conceivably link cancer treatment in childhood to mutation-driven long term sequelae.

cancer biology↗

Single cell transcriptional evolution of myeloid leukaemia of Down syndrome

Children with Down syndrome have a 150-fold increased risk of developing myeloid leukaemia (ML-DS). Unusually for a childhood leukaemia, ML-DS arises from a preleukaemic state, termed transient abnormal myelopoiesis (TAM), via a conserved sequence of mutations. Here, we examined the relationship between the genetic and transcriptional evolution of ML-DS from natural variation; a rich collection of primary patient samples and fetal tissues with a range of constitutional karyotypes. We distilled transcriptional consequences of each genetic step in ML-DS evolution, utilising single cell mRNA sequencing, complemented by phylogenetic analyses in progressive disease. We found that transcriptional changes induced by the TAM-defining GATA1 mutations are retained in, and account for most of the ML-DS transcriptome. The GATA1 transcriptome pervaded all stages of ML-DS, including progressive disease that had undergone genetic evolution. Our approach delineates the transcriptional evolution of ML-DS and provides an analytical blueprint for distilling consequences of mutations within their pathophysiological context.

cancer biology↗