Biology subjects

Buchert, M.

Publications and source records attributed to Buchert, M..

8 recordsLinked to original sources

bioRxiv2026

Circulating inflammatory ILC2s as a biomarker of gastric cancer progression

Gastric cancer is frequently diagnosed at an advanced stage, contributing to poor patient outcomes and highlighting the need for blood-based biomarkers that can detect disease earlier and track progression. We previously showed that a tuft cell-IL25-type 2 innate lymphoid cell (ILC2) circuit promotes gastric metaplasia and gastric tumour development, but whether this pathway gives rise to a circulating ILC2 population remained unknown. Here, we show that IL25-responsive inflammatory ILC2s (iILC2s) emerge in the blood across gastric disease progression and are selectively associated with gastric tumour contexts. Using multiple mouse models spanning SPEM, early gastric adenoma, and advanced gastric cancer, we found that circulating ILC2s increased progressively with disease severity, with the dominant increase occurring in the IL17RB+ iILC2 subset. This response was not observed in pancreatic or ovarian tumour models, indicating that circulating iILC2 mobilisation is not a general consequence of tumour burden. Instead, mobilisation was linked to gastric disease and accompanied by increased ILC2 accumulation in distal mucosal tissues. Genetic tuft cell ablation or therapeutic blockade of IL25 or IL13 significantly reduced circulating iILC2s, demonstrating that this response depends on the tuft cell-IL25 circuit. In vivo, mobilised iILC2s were associated with enhanced growth of distal tumour implants, supporting a functional contribution beyond the primary gastric site. Translationally, circulating ILC2s were elevated in patients with gastric inflammatory disease and gastric cancer, with the IL25-responsive subset predominating. Circulating ILC2s also showed strong discriminatory power between gastric cancer patients and healthy controls in ROC analysis, supporting their potential utility as a blood-based biomarker. Together, these findings identify circulating iILC2s as a systemic hallmark of gastric tuft cell-ILC2 signalling and establish their mechanistic and translational relevance in gastric cancer.

cancer biology↗

bioRxiv2025

Bacteriophage FNU1 negates Fusobacterium nucleatum induced cell growth and chemotherapy resistance in gastrointestinal cancer cells.

Fusobacterium nucleatum is an oncobacterium capable of promoting the growth and chemotherapy resistance of colonised tumours. Although F. nucleatum is usually susceptible to a range of antibiotics, these have been associated with worse outcomes when administered with anti-neoplastic chemotherapy. Bacteriophages are viewed as natural alternatives to antibiotics that provide bacterial-specific targeting. In this study, we demonstrated that gastric tumour tissues and cells expressed Gal-GalNac molecules that facilitate binding of the fap2 receptor on F. nucleatum, leading to increased cancer cell proliferation and migratory potential. We then employed an F. nucleatum specific bacteriophage, FNU1, to limit the effects of this oncobacteria in colon cancer and gastric cancer cell models. We demonstrated that FNU1 was able to negate the F. nucleatum-dependent growth stimulatory effects, migratory ability, induction of reactive oxygen species, and autophagy in these cell lines. F. nucleatum also inhibited apoptosis in co-cultures with colon and gastric cancer cells, and FNU1 acted synergistically with the chemotherapy agents 5-fluorouracil and oxaliplatin to induce apoptosis in these models. Treatments with bacteriophage FNU1, therefore, have the potential to augment existing cancer therapy, and further testing in animal models is warranted.

microbiology↗

bioRxiv2024

Mutant TP53 switches therapeutic vulnerability during gastric cancer progression within Interleukin-6 family cytokines

Although aberrant activation of the KRAS and PI3K pathway alongside TP53 mutations account for frequent aberrations in human gastric cancers, neither the sequence nor the individual contributions of these mutations have been clarified. Here, we establish an allelic series of mice to afford conditional expression in glandular epithelium of KrasG12D; Pik3caH1047R or Trp53R172H and/or ablation of Pten or Trp53. We find that KrasG12D;Pik3caH1047Ris sufficient to induce adenomas, and that lesions progress to carcinoma when also harboring Pten-deletions. Additional challenge with either Trp53 loss- or gain-of-function alleles further accelerated tumor progression and triggered metastatic disease. While tumor-intrinsic STAT3 signaling in response to gp130 family cytokines remained as a gatekeeper for all stages of tumor development, metastatic progression required a mutant Trp53-induced interleukin (IL)-11 to IL-6 dependency switch. Consistent with poorer survival of patients with high IL6 expression, we identify IL6/STAT3 signaling as a therapeutic vulnerability for TP53-mutant gastric cancer.

cancer biology↗

bioRxiv2023

Beclin1 is essential for intestinal homeostasis.

BECLIN1 is a component of Class III phosphatidylinositol 3-kinase complexes that orchestrates autophagy initiation and endocytic trafficking. Here we show intestinal epithelium-specific BECLIN1 deletion in adult mice led to rapid fatal enteritis with compromised gut barrier integrity, highlighting its intrinsic critical role in gut maintenance. BECLIN1-deficient intestinal epithelial cells exhibited extensive apoptosis, impaired autophagy, and stressed endoplasmic reticulum and mitochondria. Remaining absorptive enterocytes and secretory cells displayed morphological abnormalities. Deletion of the autophagy regulator, ATG7, failed to elicit similar effects, suggesting novel autophagy-independent functions of BECLIN1 distinct from ATG7. Indeed, organoids derived from BECLIN1 KO mice showed E-cadherin mislocalisation providing a mechanism linking endocytic trafficking mediated by Beclin1 and loss of intestinal barrier integrity. Our findings establish an indispensable role of BECLIN1 in maintaining mammalian intestinal homeostasis and uncover its involvement in endocytic trafficking in this process. Hence, this study has significant implications for our understanding of intestinal pathophysiology.

cell biology↗

bioRxiv2022

The kinase activity of the cancer stem cell marker DCLK1 drives gastric cancer progression by reprogramming the stromal tumor landscape

Gastric cancer (GC) is the 3rd leading cause of cancer mortality worldwide, therefore providing novel diagnostic and treatment options is crucial for at risk groups. The serine/threonine kinase doublecortin-like kinase 1 (DCLK1) is a proposed driver of GC with frequent amplification and somatic missense mutations yet the molecular mechanism how DCLK1 mediates tumorigenesis is poorly understood. We report how DCLK1 expression orchestrates complementary cancer cell intrinsic and extrinsic processes leading to a comprehensive pro-invasive and pro-metastatic reprogramming of cancer cells and tumor stroma in a DCLK1 kinase-dependent manner. Mechanistically, we identify the chemokine CXCL12 as a key promoter of the pro-tumorigenic properties downstream of DCLK1. Importantly, inhibition of the DCLK1 kinase domain reverses the pro-tumorigenic and pro-metastatic phenotype. Together, this study establishes DCLK1 as a promising, targetable master regulator of GC. TeaserDCLK1 is a druggable cancer driver of GC

cancer biology↗

bioRxiv2022

Inhibition of the tuft cell/ILC2 axis reduces gastric tumor development in mice

Although gastric cancer is a leading cause of cancer-related deaths, systemic treatment strategies remain scarce. Here we explore a metabolite-triggered circuit between epithelial tuft cells and innate lymphoid type 2 cells (ILC2) that is evolutionarily optimized for intestinal remodeling in response to helminth infection. We demonstrate that tuft cell-derived interleukin 25 (IL25) acts as an alarmin on ILC2s to induce the release of IL13 as a growth factor for tuft cells, and propose that this model drives early metaplastic remodeling and gastric tumor formation. Genetic ablation of tuft cells, ILC2s or antibody-mediated neutralization of IL13 or IL25 reduces the growth of established tumors. Thus, the tuft cell/ILC2 axis provides an opportunity to therapeutically inhibit preneoplastic lesions and early-stage gastric cancer through repurposing of antibody-mediated therapies. One-Sentence SummaryTuft cells and type 2 innate lymphoid cells offer a new therapeutic target in gastric disease.

cancer biology↗

bioRxiv2021

The minor spliceosome offers a therapeutically viable target for the treatment of a broad spectrum of cancers

Minor splicing is a second splicing system required for the correct expression of [~]700 human minor intron-containing genes (MIGs). Many MIGs are expressed in vigorously proliferating cells and are frequently dysregulated in cancer including BRAF, ERK, JNK and p38. Minor splicing is carried out by the minor spliceosome which comprises several unique components, including a 65kDa protein encoded by RNPC3. We show that Rnpc3 heterozygosity reduces tumour burden in a broad spectrum of in vivo cancer settings, without harming normal tissues. Using the collective power of zebrafish, mouse and human cancer models, we reveal a sequence of events connecting Rnpc3 deficiency and impaired splicing of MIGs to DNA damage and activation of a Tp53-dependent transcriptional program that restricts tumour burden by inducing cell cycle arrest and apoptosis. Interrogation of human liver and lung cancer transcriptomes curated in TCGA revealed that the expression of many of the genes encoding protein components of the minor spliceosome is upregulated in these cancers. This is accompanied by upregulation of the expression of MIGs that are enriched in cell cycle and DNA damage pathways. These findings suggest that cancer cells can invoke mechanisms to increase the efficiency of minor splicing to support their high proliferation rates. Finally, Kaplan Meier survival analysis shows that highly expressed MIGs are frequently associated with poor patient survival. Taken together, these results indicate that the minor spliceosome offers a therapeutically viable target for the treatment of a broad spectrum of cancers.

cancer biology↗

bioRxiv2021

EHF is essential for epidermal and colonic epithelial homeostasis and suppresses Apc-initiated colonic tumorigenesis

BackgroundEts homologous factor (EHF) is a member of the epithelial-specific Ets (ESE) transcription factors. EHF is specifically expressed in epithelial tissues, however its role in development and epithelial homeostasis is largely uncharacterized. MethodsWe generated a novel mouse strain in which the Ets DNA binding domain (exon 8) of Ehf was flanked by loxP sites (EhfLox/Lox). To inactivate Ehf in the whole body, EhfLox/Lox mice were crossed to CMVCre mice, which were then bred out to generate germline Ehf null (Ehf-/-) mice. To inactivate Ehf specifically in the intestinal epithelium, EhfLox/Lox mice were bred to tamoxifen-inducible VillinCre-ERT2 mice. EhfLox/Lox mice were also crossed to tamoxifen-inducible Cdx2CreERT2; ApcLox/+ mice to determine the impact of Ehf deletion on Apc-initiated colon cancer development. ResultsTranscripts encoding the Ets binding domain of EHF were effectively deleted in all tissues in Ehf-/- mice. Ehf-/- mice were born at the expected Mendelian ratio, but showed reduced body weight gain and developed a series of pathologies during their lifespan that led the majority of Ehf-/- mice to reach an ethical endpoint within one year of age. Most prominent of these were the development of papillomas in the chin, and abscesses in the preputial glands (males) or vulvae (females) which showed evidence of Staphylococcus and Proteus infection. Consistent with the development of papillomas, the epidermis of Ehf-/- mice showed evidence of mild hyperplasia. A subset of Ehf-/- mice also developed cataracts and corneal ulcers. EHF is highly expressed in the colonic epithelium and Ehf-/- mice displayed increased susceptibility to dextran sodium sulphate-induced colitis. This phenotype was confirmed in intestinal-specific Ehf knockout mice, and histopathological analyses revealed reduced numbers of goblet cells and extensive transcriptional reprogramming in the colonic epithelium. Finally, colon-specific deletion of Ehf enhanced Apc-initiated adenoma development, unveiling a novel, tumour suppressive role for EHF in colorectal cancer. ConclusionThe Ets DNA-binding domain of EHF is essential for post-natal homeostasis of the epidermis and colonic epithelium, and functions as a tumour suppressor in the colon.

cell biology↗