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Lopez Iglesias, C.

Publications and source records attributed to Lopez Iglesias, C..

3 recordsLinked to original sources

Adrenergic signaling induces a pro-tumorigenic B cell state in colorectal cancer

The importance of neuron-tumor crosstalk has gained increasing attention, yet its influence on the cellular and molecular landscape of colorectal cancer (CRC) remains largely unexplored. Here, we show that colonic innervation shapes the tumor immune microenvironment in a murine model of colitis-associated CRC. Although neuronal density does not affect tumor number, size, or overall burden, transcriptomic profiling of cells isolated from the tumor of hypo-innervated mice revealed extensive differential gene expression, including genes involved in immunoglobulin (Ig) signaling and the cancer-relevant hallmark avoiding immune destruction. Flow cytometry analysis of leukocyte populations demonstrated a significant reduction of B cells in the cancerous colon of hypo-innervated mice, notably a decrease in germinal center B cells and an altered class-switching profile, characterized by reduced IgA and increased IgD expression. Fluorescence and transmission electron microscopy showed that colonic B cells are primarily localized in the submucosa near neuronal processes containing varicose release sites, suggesting direct neuron-B cell interactions. Functional assays revealed that adrenergic stimulation of B cells promotes their proliferation and maturation, enhances IL-10 secretion, and alters immunoglobulin profiles. Strikingly, the transcriptome of epinephrine-treated B cells closely mirrors that of plasma cells from human CRC tissues, and the transcriptomic signature of these epinephrine-stimulated B cells associates with poorer patient survival. Together, these findings uncover an adrenergic neuron - B cell axis in CRC, providing evidence for direct neuroimmune interactions that affect B cell maturation and may influence tumor progression and therapeutic responses.

cancer biology↗

Integrin-activating Yersinia protein Invasin sustains long-term expansion of primary epithelial cells as 2D organoid sheets

Matrigel/BME, a basement membrane-like preparation, supports long-term growth of epithelial 3D organoids from adult stem cells (ASC)1,2. Here, we show that interaction between Matrigels major component Laminin111 with epithelial 6{beta}1-integrin is crucial for this process. The outer membrane protein Invasin of Yersinia is known to activate multiple integrin-{beta}1 complexes, including integrin-6{beta}1. A C-terminal integrin-binding fragment of Invasin, coated on culture plates, mediated gut epithelial cell adhesion. Addition of organoid growth factors allowed multi-passage expansion in 2D. Polarization, junction formation and generation of enterocytes, goblet cells, Paneth cells, and enteroendocrine cells was stable over time. Sustained expansion of other human-, mouse-, and even snake epithelia was accomplished under comparable conditions. The 2D organoid sheet format holds advantages over the 3D in gel format in terms of imaging, accessibility of basal and apical domains and automation for high throughput screening. Invasin represents a fully defined, affordable, versatile, and animal-free complement to Matrigel/BME.

cell biology↗

Enhanced inflammatory response mediated by parenchymal cells associates with resistance towards mTOR inhibition

Activation of the mTOR pathway is frequently found in cancer, but mTOR inhibitors have thus far failed to demonstrate significant antiproliferative efficacy in the majority of cancer types. Besides cancer cell-intrinsic resistance mechanisms, it is conceivable that mTOR inhibitors impact on non-malignant host cells in a manner that ultimately supports resistance of cancer cells. Against this background, we sought to analyze the functional consequences of mTOR inhibition in hepatocytes for the growth of metastatic colon cancer. To this end, we established a liver epithelial cell (LEC)-specific knock-out (KO) of mTOR (mTORLEC mice). We used these mice to characterize the growth of colorectal liver metastases with and without partial hepatectomy to model different clinical settings. While the LEC-specific loss of mTOR remained without effect on metastasis growth in intact liver, partial liver resection resulted in the formation of larger metastases in mTORLEC mice compared to wildtype controls. This was accompanied by significantly enhanced inflammatory activity in LEC-specific mTOR KO livers after partial liver resection. Analysis of NF-{kappa}B target gene expression and immunohistochemistry of p65 displayed a significant activation of NF-{kappa}B in mTORLEC mice, suggesting a functional importance of this pathway for the observed inflammatory phenotype. Taken together, we show an unexpected acceleration of liver metastases upon deletion of mTOR in liver epithelial cells. Our results support the notion that non-malignant host cells can contribute to resistance against mTOR inhibitors and encourage to test if anti-inflammatory drugs are able to improve the efficacy of mTOR inhibitor for cancer therapy.

cancer biology↗