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Limberger, T.

Publications and source records attributed to Limberger, T..

4 recordsLinked to original sources

Biobank of genetically defined murine prostate cancer tumoroids uncovers oncogenic pathways and drug vulnerabilities driven by PTEN-loss

Prostate cancer (PCa) is the second most common cancer in men and shows high inter- and intra-patient heterogeneity. Consequently, treatment options are limited and there is a lack of representative preclinical models. Here we establish a comprehensive biobank of murine organoids and tumoroids that reflect common patient mutations. We demonstrate that the deletion of Pten alone, or in combination with Stat3, or Tp53, drives the activation of cancer-related pathways in both prostate organoids and tumour-derived tumoroids. A medium-throughput drug screen identified two potent compounds, the PDPK1/AKT/FLT dual pathway inhibitor and the sirtuin inhibitor tenovin-6, which effectively suppressed tumoroid proliferation. Notably, these compounds also inhibited the growth of several human PCa cell lines and displayed synergistic effects when combined with the standard-of-care antiandrogen enzalutamide. Together, our findings provide evidence that murine tumoroids are versatile preclinical models for studying PCa tumorigenesis and drug sensitivities to develop novel therapeutic options for PCa patients.

cancer biology↗

Detection of Unlabeled Micro- and Nanoplastics in Unstained Tissue with Optical Photothermal Infrared Spectroscopy

In this study, we investigate the efficacy of Optical Photothermal Infrared (O-PTIR) spectroscopy, also known as mid-infrared photothermal (MIP) microscopy, for the detection of micro- and nano plastics (MNPs) down to diameters of 250 nm in mammalian tissues. Experiments with both in vitro 3D cell cultures derived from HTC116 colorectal cancer cell line and in vivo mouse tissue models were conducted to evaluate the spatial resolution limits and quality of spectra that formed the basis for label-free and non- destructive identification of MNPs. Our findings demonstrate the superior resolution of O-PTIR in imaging individual particles of 250 nm in mouse kidney tissues, surpassing the capabilities of traditional FTIR spectroscopy, which was applied as a reference technique. Furthermore, we introduce a semi-automated image analysis that incorporates machine learning algorithms to accelerate the detection process, thus improving throughput and minimizing the potential for human error. The results confirm that O-PTIR produces high-quality, artefact-free spectral images in a contact-less manner and significantly outperforms FTIR in terms of spatial resolution and signal-to-noise ratio in complex biological matrices.

biophysics↗

Cell-autonomous GP130 activation suppresses prostate cancer development via STAT3/ARF/p53-driven senescence and confers an immune-active tumor microenvironment

Prostate cancer ranks as the second most frequently diagnosed cancer in men worldwide. Recent research highlights the crucial roles GP130-mediated signaling pathways play in the development and progression of various cancers, particularly through hyperactivated STAT3 signaling. Here, we find that genetic cell-autonomous activation of the GP130 receptor in prostate epithelial cells triggers active STAT3 signaling and significantly reduces tumor growth in vivo. Mechanistically, genetic activation of GP130 signaling mediates senescence via the STAT3/ARF/p53 axis and anti-tumor immunity via recruitment of cytotoxic T-cells, ultimately impeding tumor progression. In prostate cancer patients, high GP130 mRNA expression levels correlate with better recurrence-free survival, increased senescence signals and a transition from an immune-cold to an immune-hot tumor. Our findings reveal a context-dependent role of GP130/STAT3 in carcinogenesis and a tumor-suppressive function in prostate cancer development. We challenge the prevailing concept of blocking GP130/STAT3 signaling as functional prostate cancer treatment and instead propose cell-autonomous GP130 activation as a novel therapeutic strategy.

cancer biology↗

JUN mediates senescence and immune cell recruitment to prevent prostate cancer progression

BackgroundProstate cancer develops through malignant transformation of the prostate epithelium in a stepwise, mutation-driven process. Although activator protein-1 transcription factors such as JUN have been implicated as potential oncogenic drivers, the molecular programs contributing to prostate cancer progression are not fully understood. MethodsWe analyzed JUN expression in clinical prostate cancer samples across different stages and investigated its functional role in a Pten-deficient mouse model. We performed histopathological examinations, transcriptomic analyses and explored the senescence-associated secretory phenotype in the tumor microenvironment. ResultsElevated JUN levels characterized early-stage prostate cancer and predicted improved survival in human and murine samples. Immune-phenotyping of Pten-deficient prostates revealed high accumulation of tumor-infiltrating leukocytes, particularly innate immune cells, neutrophils and macrophages as well as high levels of STAT3 activation and IL-1{beta} production. Jun depletion in a Pten-deficient background prevented immune cell attraction which was accompanied by significant reduction of active STAT3 and IL-1{beta} and accelerated prostate tumor growth. Comparative transcriptome profiling of prostate epithelial cells revealed a senescence-associated gene signature, upregulation of pro-inflammatory processes involved in immune cell attraction and of chemokines such as IL-1{beta}, CCL3 and CCL8 in Pten-deficient prostates. Strikingly, JUN depletion reversed both, senescence and senescence-associated immune cell infiltration and consequently accelerated tumor growth. ConclusionsOur results suggest that JUN acts as tumor-suppressor and decelerates the progression of prostate cancer by transcriptional regulation of senescence- and inflammation-associated genes. This study opens avenues for novel treatment strategies that could impede disease progression and improve patient outcomes.

cancer biology↗