Department of Biosciences & Medical Biology - PLUS

We proudly announce the Awardee of the Publication of the Month July: Angelika LAHNSTEINER

Metabolic disease variants rewire gene regulation through disruption of DNA G-quadruplex structures

Angelika Lahnsteiner, Victoria Ellmer, Esther Schönauer, Julia Huber, Matej Lexa, Markus Wiederstein and Angela Risch

Abstract:
Background
The global prevalence of metabolic diseases (MetDs) continues to rise and is associated with an increased cancer risk. Genome-wide association studies have identified numerous single nucleotide variants (SNVs) linked to MetDs, some within genes also implicated in tumorigenesis. G-quadruplexes (G4s) are non-canonical DNA secondary structures that regulate gene expression in diverse and context dependent ways. Variants affecting G4 structure may alter transcriptional efficiency. Notably, disease-associated variants are frequently located within or near regulatory elements and may overlap with cancer-associated alternative promoters.
Results
We systematically assess the overlap between MetD-associated SNVs and G4 motifs, and evaluate their effects on G4 stability, topology, and their potential to modulate the regulatory activity of G4s in alternative promoters. Approximately 0.9% to 1.6% of MetD-associated SNVs are located within G4 motifs (G4-SNVs), depending on the prediction tool. Effect alleles, those associated with risk or protection against MetDs, generally reduce G4 stability, regardless of their direction of association. Several G4-SNVs are mapped to cancer-associated alternative promoters, including the destabilizing MICB rs2855804 C/T variant and the stabilizing PLA2G6 rs2277844 G/A variants. In vivo G4 formation is confirmed by permanganate/S1 nuclease footprinting coupled with sequencing, while circular dichroism spectroscopy reveals allele-specific changes in G4 topology and stability. Integration of Hi-C data, histone modifications, transcription factor binding, and luciferase reporter assays further support their regulatory impact.
Conclusions
Although G4-SNVs are unlikely to be the sole disease drivers, they significantly influence transcriptional regulation, potentially contributing to allele-specific gene expression in MetD patients and their link to increased cancer risk.

The open access article can be found here: https://link.springer.com/article/10.1186/s13059-026-04147-2

Reviewed by Martina Dicker

CONGRATULATIONS!

We proudly announce the Awardee of the Publication of the Month June: Giorgia NASI

Giorgia Nasi, Leonie C. Schöftner, Lara Ronacher, Amalia Sophianidis, Julia Feiser, Teodora Aleksandrova, Oliver Nussbaumer, Andrew Hutton, Roland Zauner, Johanna Moser-Waxenecker, Suraj R. Varkhande, Anshu Sharma, Monika Ettinger, Teresa Burner, Martin Laimer, Christina Guttmann-Gruber, Iris K. Gratz

Abstract:
Gamma delta (γδ) T cells are critical for tissue immune surveillance and their presence in tumors correlates with a favorable prognosis, highlighting their therapeutic potential. Although γδ T cells are abundant in the skin, their therapeutic value in skin cancer has remained largely unexplored due to challenges in isolating sufficient numbers of γδ T cells from human tissues and a lack of suitable preclinical models for skin cancer. Here, we are using innovative methods to expand human cutaneous γδ T cells ex vivo, enabling us to investigate their therapeutic potential in a human cutaneous squamous cell carcinoma (cSCC) mouse model. In this model, γδ T cells were specifically recruited to and maintained in the cSCC xenograft. These tumor-infiltrating cells exhibited an activated, cytotoxic phenotype and demonstrated effective antitumor activity in vivo. Collectively, our findings provide preclinical evidence supporting human skin–resident γδ T cells as a promising immunotherapeutic approach for treating skin cancers such as cSCC.

The open access article can be found here:
https://www.science.org/doi/10.1126/sciadv.aec7215

Reviewed by Diana Amend

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We proudly announce the Awardee of the Publication of the Month April: Rupert KLAUSHOFER

Positional scanning and computational modeling reveal determinants of legumain transpeptidase activity

Rupert Klaushofer, Sven O. Dahms, Hans Brandstetter, Elfriede Dall

Abstract:
Legumain is a lysosomal cysteine protease that plays a central role in antigen processing for MHC class II presentation. Beyond its canonical proteolytic activity, legumain can also function as a peptide ligase or transpeptidase. This non-canonical activity becomes particularly relevant under pathophysiological conditions such as cancer and neurodegeneration, where legumain translocates to near-neutral pH environments, including the cytosol, nucleus, and extracellular space, that favor ligation over hydrolysis. Here, we combine in vitro positional scanning with in silico substrate profiling to elucidate the molecular determinants governing human legumain-mediated peptide cyclization. We identify glycine residues at the P1' and P1" positions and basic residues at P2'/P2″ as key drivers of efficient cyclization. Guided by these insights, we designed an optimized substrate exhibiting substantially enhanced cyclization efficiency. Computational analysis not only recapitulated the experimental observations but also predicted a covalent inhibition mechanism involving a P1' cysteine, revealed a kcat-tuning switch embedded within the substrate, and highlighted its potential for developing high-performance fluorogenic substrates. Together, these findings establish the structural basis for the rational design of activity-selective legumain probes and inhibitors, with potential applications in therapeutic development and diagnosis.

The open access article can be found here:
https://onlinelibrary.wiley.com/doi/10.1002/pro.70563

Reviewed by Florian Wolff

Congratulations!

Das Team des PDI-PLUS hat folgende Masterarbeit zu vergeben: Photodynamische Insektizide zur Bekämpfung invasiver Fruchtfliegen.

Beginn ist ab sofort (Mai, Juni 2026) möglich. Alle Details anbei.

We proudly announce the Awardees of the Publication of the Month March: Veronika SCHÄPERTÖNS, Larissa HOFER & Thomas BERGER

Effects of feeding strategies on culture performance and product quality in NISTCHO

Veronika Schäpertöns, Larissa Hofer, Thomas Berger, Jerneja Štor, Nicolas Marx, Wolfgang Esser-Skala, Thomas Rauter, Dominik Hofreither, Laura Liesinger, Peter Filzmoser, Ruth Birner-Gruenberger, Christian G. Huber, Nicole Borth & Nikolaus Fortelny

Abstract:
Monoclonal antibody N-glycosylation is a critical quality attribute influencing therapeutic safety and efficacy, and is strongly influenced by bioprocess design. NISTCHO, a publicly available Chinese hamster o***y producer cell line, is increasingly encouraged for use as a reference system. However, the impact of feeding strategies on cellular performance and N-glycosylation has not been assessed. Here, we applied multivariate analysis of compositional N-glycan data to assess how feeding strategies influence N-glycan composition of cNISTmAb. We varied feeding strategies in frequency, glucose supply, and galactose/manganese supplementation. Feeding frequency had minimal impact on quality attributes but strongly affected culture performance, with every-other-day feeding improving titers and cell-specific productivity. High glucose availability supported growth and productivity. Low glucose strategies reduced titers and shifted N-glycosylation towards non-galactosylated and fucosylated species, despite lactate accumulation remaining within favorable ranges. Galactose and manganese consistently increased antibody galactosylation, with galactose additionally serving as an auxiliary carbon source, extending cell viability. Importantly, mAb glycation remained stable across all feeding strategies at harvest. Overall, these results demonstrate that feed composition and timing can be used to tune both cellular performance and mAb glycosylation, establishing NISTCHO as a robust benchmark for standardized process-quality studies.

The open access article can be found here:
https://www.nature.com/articles/s41540-026-00686-3

Reviewed by Theresa Neuper

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