Biology subjects

Tran, W.

Publications and source records attributed to Tran, W..

5 recordsLinked to original sources

bioRxiv2025

tRNA modifications are required for stress granule formation and melanoma metastasis

Metastasis is the leading cause of cancer related deaths, however therapies specifically targeting metastasis are lacking and remain a dire therapeutic need in the clinic. Metastasis is a highly inefficient process that is inhibited by extracellular stress. Therefore, metastasizing cells that ultimately survive and successfully colonize distant organs must undergo molecular rewiring to mitigate stress. Wobble uridine modifications, especially 5-methoxycarbonylmethyl-2-thiouridine (mcm5s2U34), have been implicated in stress response and poor prognosis of cancer patients. We use a patient derived xenograft (PDX) model of melanoma metastasis to study the role of the mcm5s2U34 modification in the stress response of metastasizing cells. We find that upon depletion of elongator acetyltransferase complex subunit 1 (ELP1)-- a component of the mcm5s2U34 pathway on [Formula], and [Formula] --codon-biased translation, migration, invasion, and metastatic burden in vivo is reduced. Further, we observe that stress granule components are enriched in a subset of codon-biased genes that are exclusively upregulated at the protein level in metastatic nodules compared to the primary tumor in our PDX model. Additionally, upon knockdown of ELP1, stress granule components have decreased protein expression with no significant change to their mRNA levels. Efficient translation, mediated by the carboxy-methylation arm of the mcm5s2U34 modification, is required for metastasizing cancer cells to withstand stress via stress granule formation and increase survival throughout the metastatic cascade. This makes the mcm5s2U34 machinery a potentially actionable therapeutic target, specific to metastatic disease.

cancer biology↗

bioRxiv2025

Missense3D-PTMdb an interactive web resource to explore and visualize genetic variants and post-translational modifications sites (PTMs) using AlphaFold 3D models

Only a fraction of the >11 million missense variants identified in the human population has a known damaging or tolerated clinical impact. Post-translational modifications (PTMs), such as phosphorylation, glycosylation and ubiquitination, are key regulators of protein function and structure, and are critical for protein localisation, stability and interactions with other molecules. The ability of a protein to undergo PTMs, is subject to a correctly folded protein structure, and the recognition and binding of enzymes to specific amino acid motifs in close proximity to residues that undergo PTMs [PTM residue]. AlphaFold models provide an unprecedented opportunity to perform sequence-structure mapping of variants, which are in close linear or spatial proximity to a PTM site and should have their impact on protein function experimentally investigated. We present Missense3D-PTMdb, a "one-stop-shop" interactive web tool that provides a user-friendly sequence-structure mapping of 20,235 human proteins to 11,544,303 naturally occurring human missense variants, 203,775 PTM sites and their neighbours in sequence and 3D structure space using AlphaFold generated 3D models of the human proteome. Additionally, the sequence-structure mapping tool allows visualization and exploration of any human variant not currently stored in the database. Missense3D-PTMDb is freely available at https://missense3d.bc.ic.ac.uk/ptmdb.

genetics↗

bioRxiv2024

PGC-1α drives small cell neuroendocrine cancer progression towards an ASCL1-expressing subtype with increased mitochondrial capacity

Adenocarcinomas from multiple tissues can evolve into lethal, treatment-resistant small cell neuroendocrine (SCN) cancers comprising multiple subtypes with poorly defined metabolic characteristics. The role of metabolism in directly driving subtype determination remains unclear. Through bioinformatics analyses of thousands of patient tumors, we identified enhanced PGC-1--a potent regulator of oxidative phosphorylation (OXPHOS)--in various SCN cancers (SCNCs), closely linked with neuroendocrine differentiation. In a patient-derived prostate tissue SCNC transformation system, the ASCL1-expressing neuroendocrine subtype showed elevated PGC-1 expression and increased OXPHOS activity. Inhibition of PGC-1 and OXPHOS reduced the proliferation of SCN lung and prostate cancer cell lines and blocked SCN prostate tumor formation. Conversely, enhancing PGC- 1 and OXPHOS, validated by small-animal Positron Emission Tomography mitochondrial imaging, tripled the SCN prostate tumor formation rate and promoted commitment to the ASCL1 lineage. These results establish PGC-1 as a driver of SCNC progression and subtype determination, highlighting novel metabolic vulnerabilities in SCNCs across different tissues. STATEMENT OF SIGNIFICANCEOur study provides functional evidence that metabolic reprogramming can directly impact cancer phenotypes and establishes PGC-1-induced mitochondrial metabolism as a driver of SCNC progression and lineage determination. These mechanistic insights reveal common metabolic vulnerabilities across SCNCs originating from multiple tissues, opening new avenues for pan-SCN cancer therapeutic strategies.

cancer biology↗

bioRxiv2023

Defining T cell receptor repertoires using nanovial-based affinity and functional screening

The ability to selectively bind to antigenic peptides and secrete cytokines can define populations of cells with therapeutic potential in emerging T cell receptor (TCR) immunotherapies. We leverage cavity-containing hydrogel microparticles, called nanovials, each coated with millions of peptide-major histocompatibility complex (pMHC) monomers to isolate antigen-reactive T cells. T cells are captured and activated by pMHCs and secrete cytokines on nanovials, allowing sorting based on both affinity and function. The TCRs of sorted cells on nanovials are sequenced, recovering paired {beta}-chains using microfluidic emulsion-based single-cell sequencing. By labeling nanovials having different pMHCs with unique oligonucleotide-barcodes we could link TCR sequence to targets with 100% accuracy. We identified with high specificity an expanded repertoire of functional TCRs targeting viral antigens compared to standard techniques. One-sentence SummaryAffinity and secretion-based screening of antigen-specific T cells using nanovials defines a functional TCR repertoire

bioengineering↗

bioRxiv2019

Loading effects on the performance of needle free jet injections in different skin models

Intradermal delivery of vaccines with jet injection is one of the leading alternatives to conventional delivery with hypodermic needles via the Mantoux technique. However, for a given fluid, the effects of various parameters related to injector design, as well as skin properties are still not well understood. Whilst the key design parameters are orifice diameter, jet speed, ampoule volume, and standoff distances, we must also consider applied load of the device on the skin, and axial skin tension. These parameters are all studied herein using different ex-vivo models (guinea pig, pig and human skin) and different fluid viscosities. We find that the applied load can have a significant effect on the amount of drug delivered through the skin, as well as the fluid dispersion pattern in the intradermal tissues. Regardless of skin type or fluid viscosity, we show that minimal standoff and applied loads of approximately 1 kg should be used to maximize injection efficiency when targeting intradermal tissue.

bioengineering↗