bims-instec 2023-03-26 papers

Issue of 2023‒03‒26
five papers selected by
Maria-Virginia Giolito
Free University of Brussels

Cancer Sci. 2023 Mar 21.

RHAMM marks proliferative subpopulation of human colorectal cancer stem cells.

Michitaka Nakano, Ryosuke Taguchi, Yoshikane Kikushige, Taichi Isobe, Kohta Miyawaki, Shinichi Mizuno, Nobuhiro Tsuruta, Fumiyasu Hanamura, Kyoko Yamaguchi, Takuji Yamauchi, Hiroshi Ariyama, Hitoshi Kusaba, Masafumi Nakamura, Takahiro Maeda, Calvin J Kuo, Eishi Baba, Koichi Akashi.

The cancer stem cell (CSC) theory features typically rare self-renewing subpopulation that reconstitute the heterogeneous tumor. Identification of molecules which characterize the feature of CSCs is a key imperative for further understanding of tumor heterogeneity and for the development of novel therapeutic strategies. However, the use of conventional markers of CSCs is still insufficient for the isolation of bona fide CSCs. We investigated organoids which are miniature forms of tumor tissues with reconstructing cellular diversity to identify specific marker to characterize CSCs in heterogeneous tumors. Here, we report that receptor for hyaluronan-mediated motility (RHAMM) expresses in a subpopulation of CD44+ conventional human colorectal CSC fraction. Single-cell transcriptomics of organoids highlighted RHAMM positive proliferative cells that revealed distinct characteristics among the various cell types. Prospectively isolated RHAMM+ CD44+ cells from the human colorectal cancer tissues showed highly proliferative character with self-renewal ability in comparison with the other cancer cells. Furthermore, inhibition of RHAMM strongly suppressed organoids formation in vitro and inhibited the tumor growth in vivo. Our findings suggest that RHAMM is a potential therapeutic target because it is a specific marker of the proliferative subpopulation within the conventional CSC fraction.

DOI: https://doi.org/10.1111/cas.15795

Am J Physiol Gastrointest Liver Physiol. 2023 Mar 21.

Absence of gut microbiota impairs depletion of Paneth cells but not goblet cells in germ-free Atoh1lox/lox VilCreERT2 mice.

Mohsin Hassan, Oriol Juanola, Stefania Huber, Philipp Kellmann, Jakob Zimmermann, Edoardo Lazzarini, Stephanie C Ganal-Vonarburg, Mercedes Gomez de Agüero, Sheida Moghadamrad.

Mouse atonal homolog 1 (Math1/Atoh1) is a basic helix-loop-helix transcription factor important for the differentiation of secretory cells within the intestinal epithelium. The analysis of Paneth depletion efficiency upon Math1lox/loxVilCreERT2 (Math1∆IEC) mice treatment with Tamoxifen in the presence or absence of intestinal microbiota, showed a failure on Paneth cell depletion in germ-free mice as compared to SPF mice. However, goblet cells were efficiently depleted in Math1∆IEC germ-free mice. The gene expression of Math1 was significantly reduced in the ileum of germ-free Math1∆IEC mice 5 days post tamoxifen injection as compared to germ-free control, but its protein expression was still detectable in the nuclei of epithelial cells in the crypts. Germ-free mice showed low proliferative ileal crypts as well as apoptotic cells that were mainly detected in the tip of the villus, consistent with a slow turnover rate of epithelial cells. Although Paneth cells were not depleted in germ-free Math1∆IEC mice for the first 7 weeks after the last tamoxifen injection - far already from the 5 days timelaps observed in SPF conditions- but an incomplete depletion of Paneth cells was observed 14 weeks after last tamoxifen injection. Colonization of germ-free mice restored the phenotype observed in SPF mice, highlighting the regulatory role of gut microbes in our model. We conclude that absence of intestinal microbiota in Math1∆IEC mice is associated with reduced epithelial cell renewal and delays the depletion of preexisting Paneth cells.

Keywords: Atoh1; Cre recombinase; Math1lox/loxVilCreERT2; Paneth cells; germ-free

DOI: https://doi.org/10.1152/ajpgi.00123.2022

BMC Cancer. 2023 Mar 23. 23(1): 267

Exposure to nonanoic acid alters small intestinal neuroendocrine tumor phenotype.

Bilal Almobarak, Vishal Amlani, Linda Inge, Tobias Hofving, Andreas Muth, Ola Nilsson, Martin Johansson, Yvonne Arvidsson, Erik Elias.

BACKGROUND: Small intestinal neuroendocrine tumors (SI-NET) are highly differentiated and genetically stable malignant tumors, yet they often present with advanced metastatic spread at the time of diagnosis. In contrast to many other types of malignant tumors, primary SI-NET are often asymptomatic and typically smaller in size compared to adjacent lymph node metastases. This study explores the hypothesis that stimulating the chemosensing olfactory receptor 51E1 (OR51E1) decreases SI-NET proliferation suggesting a mechanism that explains a difference in proliferative rate based on tumor location.METHODS: Clinical data was used to address difference in tumor size depending on location. A SI-NET tissue microarray was used to evaluate expression of OR51E1 and olfactory marker protein (OMP). Primary cultured tumor cells from 5 patients were utilized to determine the effect of OR51E1 agonist nonanoic acid on metabolic activity. The SI-NET cell line GOT1 was used to determine effects of nonanoic acid on the transcriptome as well as long-term effects of nonanoic acid exposure with regards to cell proliferation, serotonin secretion, alterations of the cell-cycle and morphology.
RESULTS: Tumor size differed significantly based on location. OR51E1 and OMP were generally expressed in SI-NET. Primary SI-NET cells responded to nonanoic acid with a dose dependent altered metabolic activity and this was replicated in the GOT1 cell line but not in the MCF10A control cell line. Nonanoic acid treatment in GOT1 cells upregulated transcripts related to neuroendocrine differentiation and hormone secretion. Long-term nonanoic acid treatment of GOT1 cells decreased proliferation, induced senescence, and altered cell morphology.
CONCLUSION: Our results raise the possibility that exposure of intraluminal metabolites could represent a mechanism determining aspects of the SI-NET tumor phenotype. However, we could not causally link the observed effects of nonanoic acid exposure to the OR51E1 receptor.

Keywords: Neuroendocrine; OR51E1; Olfactory receptor; SBNET; SI-NET; SINET; Small intestine

DOI: https://doi.org/10.1186/s12885-023-10722-8

Semin Cell Dev Biol. 2023 Mar 20. pii: S1084-9521(23)00071-X. [Epub ahead of print]

The emerging roles of the cytoskeleton in intestinal epithelium homeostasis.

Louisiane Perrin, Danijela Matic Vignjevic.

The intestinal epithelium must absorb many nutrients and water while forming a barrier that is impermeable to pathogens present in the external environment. Concurrently to fulfill this dual role, the intestinal epithelium is challenged by a rapid renewal of cells and forces resulting from digestion. Hence, intestinal homeostasis requires precise control of tissue integrity, tissue renewal, cell polarity, and force generation/transmission. In this review, we highlight the contribution of the cell cytoskeleton- actin, microtubules, and intermediate filaments- to intestinal epithelium homeostasis. With a focus on enterocytes, we first discuss the role of these networks in the formation and maintenance of cell-cell and cell-matrix junctions. Then, we cover their role in intracellular trafficking related to the apicobasal polarity of enterocytes. Finally, we report on the cytoskeletal changes that occur during tissue renewal. In conclusion, the importance of the cytoskeleton in maintaining intestinal homeostasis is emerging, and we think this field will keep evolving.

DOI: https://doi.org/10.1016/j.semcdb.2023.03.008

J Cell Mol Med. 2023 Mar 23.

NR3C2 inhibits the proliferation of colorectal cancer via regulating glucose metabolism and phosphorylating AMPK.

Hui Liu, Wenqi Lei, Zhigui Li, Xiaodong Wang, Liming Zhou.

We aim to investigate the roles and mechanisms of NR3C2 in colorectal cancer (CRC). The expression of NR3C2 in CRC tumours and paired paracancerous tissues of 71 CRC patients and five CRC cell lines was detected by western blotting, immunohistochemistry and real-time reverse-transcription PCR. Moreover, NR3C2 was overexpressed or knocked down in CRC cells by lentiviral vector transfection. The proliferation of cells was measured by MTT, colony formation assay and flow cytometry. Glucose metabolism was assessed by detecting lactate production, glucose consumption and ATP production. Western blotting and real-time reverse-transcription PCR were used to detect the expression of AMPK, LDHA and HK2. The expression of NR3C2 was significantly decreased in CRC tumours compared to paracancerous tissues, which was correlated with distant metastasis, poor prognosis and advanced stages of CRC patients. Overexpressing NR3C2 suppressed the proliferation and promoted the G2/M cell cycle arrest of CRC cells. Furthermore, NR3C2 inhibited glucose metabolism by decreasing the expression of HK2 and LDHA. The phosphorylation of AMPK was also downregulated in CRC cells overexpressing NR3C2. This study demonstrated that NR3C2 inhibited the proliferation of CRC by inhibiting glucose metabolism and phosphorylation of AMPK which may serve as a therapeutic target for CRC.

Keywords: AMPK; NR3C2; colorectal cancer; glucose metabolism

DOI: https://doi.org/10.1111/jcmm.17706