Biology subjects

Andersson, T.

Publications and source records attributed to Andersson, T..

6 recordsLinked to original sources

bioRxiv2026

Tumor-specific Kinase Motif Enrichment Analysis Identifies Personalized Therapeutic Cancer Targets

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are an uncommon and poorly understood malignancy with low mutational burden, lacking well-defined oncogenic drivers. GEP-NET mortality frequently results from extensive hepatic metastases. Accordingly, we interrogated phosphoproteomic data from GEP-NET liver metastases and patient-matched uninvolved liver to identify tumor-specific signaling and targetable tumor vulnerabilities using Kinase Motif Enrichment Analysis (KMEA), a new tool leveraging the recent Kinase Library compendium of the substrate motif specificity for nearly the entire human kinome. KMEA identified patient tumor-specific upregulation of mTOR or casein kinase 2 (CK2) activity that would be undiscoverable by standard personalized genomic and transcriptomic approaches. Striking concordance was observed between KMEA predictions for specific tumors, and their sensitivity to inhibitors of mTOR or CK2 using patient tumor-derived organoids. These findings reveal potential clinically-actionable protein kinases hyperactivated in GEP-NETs, and more broadly indicate a general method for personalized cancer treatment using phosphoproteomics and KMEA-derived kinase activity signatures.

cancer biology↗

bioRxiv2026

Hepatobiliary Progenitor-like Reprogramming in Liver Metastases

Metastatic progression requires cancer cells to adapt to the unique constraints of distant organ microenvironments, yet the mechanisms that drive organ-specific adaptations remain poorly understood. Here, we show that the liver actively rewrites metastatic cancer cell identity, driving tumor cells toward a hepatobiliary progenitor-like state. Through integrated transcriptomic, proteomic, metabolomic, and epigenomic analyses of patient-derived rapid-autopsy samples and experimental models, we identify this state as selectively enriched in liver metastases. It is characterized by co-activation of hepatic and biliary/progenitor regulators HNF4A and SOX9 and is observed across multiple epithelial cancers, indicating a conserved response to the hepatic niche. Mechanistically, hepatocyte-derived TGF-{beta} and hypoxia converge to activate a HIF-1-ACLY axis, increasing nuclear acetyl-coenzyme A availability and histone acetylation at hepatic lineage regulatory elements to drive hepatobiliary reprogramming. This coordinated niche-response program can be captured transcriptionally and is associated with inferior overall survival. Disruption of this pathway suppresses hepatic reprogramming and impairs liver metastatic fitness. These findings identify the liver as an active determinant of metastatic cell fate, linking microenvironmental signaling to metabolic and chromatin remodeling programs that enable lineage plasticity. More broadly, they reveal organ-specific reprogramming as a fundamental principle of metastasis and a therapeutic vulnerability in liver metastases.

cancer biology↗

bioRxiv2026

Molecular mechanism of redox regulation of the alpha-carboxysomal carbonic anhydrase CsoSCA

Carboxysomes are protein-based organelles that form the core of the bacterial CO2-concentrating mechanism (CCM) by elevating CO2 levels around Rubisco. They encapsulate Rubisco and carbonic anhydrase (CA) within a protein shell that, after closure, excludes cytosolic reductants. Because cytosolic CA activity would short-circuit the CCM, CA activity must be confined to the carboxysome, yet how -carboxysomes achieve this has remained unknown. Here we show that CsoSCA, the -carboxysomal CA, is redox-regulated: inactive under reducing conditions, active under oxidizing. This regulation is mediated by a conserved vicinal cysteine pair distal from the active site. CryoEM structures of Halothiobacillus neapolitanus CsoSCA under active and inactive conditions, and of an inactive cysteine variant, reveal that redox conditions modulate global conformational dynamics that reorganize the active site for catalysis. These findings advance the understanding of -carboxysome regulation and couple CsoSCA activation to lumenal oxidation during carboxysome maturation.

biochemistry↗

bioRxiv2025

RNA-coupled CRISPR Screens Reveal ZNF207 as a Regulator of LMNA Aberrant Splicing in Progeria

Despite progress in understanding pre-mRNA splicing, the regulatory mechanisms controlling most alternative splicing events remain unclear. We developed CRASP-Seq, a method that integrates pooled CRISPR-based genetic perturbations with deep sequencing of splicing reporters, to quantitively assess the impact of all human genes on alternative splicing from a single RNA sample. CRASP-Seq identifies both known and novel regulators, enriched for proteins involved in RNA splicing and metabolism. As proof-of-concept, CRASP-Seq analysis of an LMNA cryptic splicing event linked to progeria uncovered ZNF207, primarily known for mitotic spindle assembly, as a regulator of progerin splicing. ZNF207 depletion enhances canonical LMNA splicing and decreases progerin levels in patient-derived cells. High-throughput mutagenesis further showed that ZNF207s zinc finger domain broadly impacts alternative splicing through interactions with U1 snRNP factors. These findings position ZNF207 as a U1 snRNP auxiliary factor and demonstrate the power of CRASP-Seq to uncover key regulators and domains of alternative splicing. Main PointsO_LICRASP-Seq: RNA-coupled CRISPR screen quantifying gene and domain impact on splicing C_LIO_LIProfiling of five events identified 370 genes influencing alternative splicing C_LIO_LIZNF207 regulates splicing by interacting with U1 snRNP via its zinc-finger domains C_LIO_LIZNF207 depletion corrects LMNA aberrant splicing causing progeria C_LI

genetics↗

bioRxiv2024

Tuft cell IL-17RB restrains IL-25 bioavailability and reveals context-dependent ILC2 hypoproliferation

The tuft cell-ILC2 circuit orchestrates rapid type 2 responses upon detecting microbe-derived succinate and luminal helminths. Our findings delineate key mechanistic steps, involving IP3R2 engagement and Ca2+ flux, governing IL-25 production by tuft cells triggered by succinate detection. While IL-17RB plays a pivotal intrinsic role in ILC2 activation, it exerts a regulatory function in tuft cells. Tuft cells exhibit constitutive Il25 expression, placing them in an anticipatory state that facilitates rapid production of IL-25 protein for ILC2 activation. Tuft cell IL-17RB is crucial for restraining IL-25 bioavailability, preventing excessive tonic ILC2 stimulation due to basal Il25 expression. Suboptimal ILC2 stimulation by IL-25 resulting from tuft cell Il17rb-deficiency or prolonged succinate exposure induces a state of hypoproliferation in ILC2s, also observed in chronic helminth infection. Our study offers critical insights into the regulatory dynamics of IL-25 in this circuit, highlighting the delicate tuning required for responses to diverse luminal states.

immunology↗

bioRxiv2023

Structure-function analysis of a calcium-independent metacaspase reveals a novel proteolytic pathway for lateral root emergence

Metacaspases are part of an evolutionarily broad family of multifunctional cysteine proteases, involved in disease and normal development. Despite the extensive study of metacaspases in the two decades since their discovery, the structure-function relationship of metacaspases remains poorly understood. Furthermore, previous studies on their function have been thwarted by the redundancy in gene copy number and potential phenotypic suppression of genetic mutations, especially in plants. Here, we have solved the X-ray crystal structure of an Arabidopsis thaliana type II metacaspase (AtMCA-IIf) that belongs to a particular sub-group that does not require calcium ions for activation. Compared to crystal structures of other metacaspases and caspases, the AtMCA-IIf active site is structurally similar and poses a conundrum for the catalytic mechanism of the cysteine-histidine dyad. To study metacaspase activity in plants, we developed an in vitro chemical screen to identify small molecule metacaspase inhibitors. Several hits with a minimal thioxodihydropyrimidine-dione (TDP) structure were identified, some being specific inhibitors of AtMCA-IIf. We provide a mechanistic basis for inhibition by the TDP-containing compounds through molecular docking onto the AtMCA-IIf crystal structure. Finally, a TDP-containing compound (TDP6) was effective at inhibiting lateral root emergence in vivo, likely through the inhibition of metacaspases that are specifically expressed in the endodermal cells overlaying developing lateral root primordia. In the future, the small compound inhibitors and crystal structure of AtMCA-IIf can be used to study metacaspases in various other species, such as important human pathogens including those causing neglected diseases.

plant biology↗