Biology subjects

Rawson, F.

Publications and source records attributed to Rawson, F..

4 recordsLinked to original sources

bioRxiv2024

Tackling Anticancer Drug Resistance and Endosomal Escape in Aggressive Brain Tumors Using Bioelectronics

Chemotherapy resistance and endosomal entrapment, controlled by intracellular trafficking processes, are major factor in treatment failure. Here, we test the hypothesis that external electrical stimulus can be used to modulate intracellular trafficking of chemotherapeutic drugs in most common malignant brain tumors in childhood (medulloblastoma) and gold nanoparticles (GNPs) in adulthood (glioblastoma). We demonstrate that application of alternating current (AC) with frequencies ranging from KHz-MHz and low strength (1 V/cm) lead to killing of cisplatin and vincristine resistant (mediated by extracellular vesicles) medulloblastoma cell lines. On the other hand, in primary glioblastoma cells high frequency AC (MHz) regulated the endosomal escape of GNPs. No significant effect on the viability of the control medulloblastoma cells (resistant cells cultured in drug free media and non-resistant cells) and glioblastoma cells after AC treatment confirmed targeting of intracellular trafficking process. This work supports future application of AC in drug delivery and brain cancer therapy.

pharmacology and toxicology↗

bioRxiv2023

Wireless Electrical-Molecular Quantum Signalling for Cancer Cell Induced Death

Quantum biological tunnelling for electron transfer (QBET) is involved in controlling cellular behaviour. Control of electrical-molecular communication could revolutionise the development of disruptive technologies for understanding and modulating electrically induced molecular signalling. Current communication technology is not appropriate for interfacing with cells at a spatial/temporal level equivalent to the native biological signalling. This limits our ability to tune cell function by controlling single molecular events. Here, we merge wireless nano-electrochemical tools with cancer cells. Gold-bipolar nanoelectrodes functionalised with redox active species were developed as electric field stimulated bio-actuators, that we term bio-nanoantennae. We show that a remote electrical input regulates electron transport between the redox molecules on the bio-nanoantennae in a selective manner. The wireless modulation of electron transport results in QBET triggering apoptosis in patient-derived cancer cells, representing electrical-induced induced controlled molecular signalling. Transcriptomics data highlight the electric field-induced nanoantenna targets the cancer cells in a unique manner. The insight concerning action and functional nanomaterials opens a plethora of applications in healthcare. This approach may lead to new quantum-based medical diagnostics and treatments, as well as a fundamental understanding of biological physics.

biophysics↗

bioRxiv2022

Engineering Nanowires in Bacteria to Elucidate Electron Transport Structural Functional Relationships

Bacterial pilin nanowires are protein complexes, suggested to possess electroactive capabilities forming part of the cells bioenergetic programming. Their role is thought to be linked to facilitating electron transfer with the external environment to permit metabolism and cell-to-cell communication. There is a significant debate, with varying hypotheses as to the nature of the proteins currently lying between type-IV pilin-based nanowires and polymerised cytochrome-based filaments. Importantly, to date, there is a very limited structure-function analysis of these structures within whole bacteria. In this work, we engineered Cupriavidus necator H16, a model autotrophic organism to express differing aromatic modifications of type-IV pilus proteins to establish structure-function relationships on conductivity and the effects this has on pili structure. This was achieved via a combination of high-resolution PeakForce tunnelling atomic force microscopy (PeakForce TUNA) technology, alongside conventional electrochemical approaches enabling the elucidation of conductive nanowires emanating from whole bacterial cells for the first time. This work is the first example of functional type-IV pili protein nanowires produced under aerobic conditions using a CN chassis. This work has far-reaching consequences in understanding the basis of bio-electrical communication between cells and with their external environment. O_FIG O_LINKSMALLFIG WIDTH=182 HEIGHT=200 SRC="FIGDIR/small/510814v2_ufig1.gif" ALT="Figure 1"> View larger version (90K): org.highwire.dtl.DTLVardef@134d026org.highwire.dtl.DTLVardef@4d84f3org.highwire.dtl.DTLVardef@15379fcorg.highwire.dtl.DTLVardef@16d942c_HPS_FORMAT_FIGEXP M_FIG C_FIG Graphical abstract displaying theoretical PilA monomer models (left), PeakForce TUNA atomic force microscopy contact current images (right) of wild-type (top) and modified with increased tyrosine content (bottom) PilA filaments expressed by Cupriavidus necator H16 cells.

bioengineering↗

bioRxiv2019

Multiplex in situ hybridization within a single transcript: RNAscope reveals dystrophin mRNA dynamics

Dystrophin plays a vital role in maintaining muscle health, yet low mRNA expression, lengthy transcription time and the limitations of traditional in-situ hybridization (ISH) methodologies mean that the dynamics of dystrophin transcription remain poorly understood. RNAscope is highly sensitive ISH method that can be multiplexed, allowing detection of individual transcripts at sub-cellular resolution, with different target mRNAs assigned to distinct fluorophores. We present a novel approach, instead using RNAscope probes targeted to 5 and 3 regions of the same transcript: labelling muscle dystrophin mRNA in this manner allows transcriptional dynamics to be deciphered in health and disease, resolving both nascent myonuclear transcripts and exported mature mRNAs (the latter absent in dystrophic muscle, yet restored following therapeutic intervention). We show that even in healthy muscle, immature dystrophin mRNA predominates (60-80% of total), with the surprising implication that the half-life of a mature transcript is markedly shorter than the time invested in transcription: at the transcript level, supply may exceed demand. Our findings provide unique spatiotemporal insight into the behaviour of this long transcript (with implications for therapeutic approaches), and further suggests this modified multiplex ISH approach is well-suited to long genes, offering a highly tractable means to reveal complex transcriptional dynamics.

cell biology↗