bims-instec 2023-10-08 papers

bims-instec

Biomed News

on Intestinal stem cells and chemoresistance in colon cancer and intestinal regeneration

Issue of 2023‒10‒08
seventeen papers selected by
Maria-Virginia Giolito, Université Catholique de Louvain

IFNγ-Stat1 axis drives aging-associated loss of intestinal tissue homeostasis and regeneration.
Predictive Impact of RNF43 Mutations in Patients With Proficient Mismatch Repair/Microsatellite Stable BRAFV600E-Mutated Metastatic Colorectal Cancer Treated With Target Therapy or Chemotherapy.
Intestinal-specific Hdac3 deletion increases susceptibility to colitis and small intestinal tumour development in mice fed a high fat diet.
Mechanisms of resistance to EGFR-targeted therapies in colorectal cancer: more than just genetics.
Transcriptional Regulation of Metabolism in the Intestinal Epithelium.
Cancer cell plasticity, stem cell factors, and therapy resistance: how are they linked?
Inhibiting BRAF/EGFR/MEK suppresses cancer stemness and drug resistance of primary colorectal cancer cells.
An early-life microbiota metabolite protects against obesity by regulating intestinal lipid metabolism.
Epithelial zonation along the mouse and human small intestine defines five discrete metabolic domains.
DYRK2 promotes chemosensitivity via p53-mediated apoptosis after DNA damage in colorectal cancer.
Dietary regulation of intestinal stem cells in health and disease.
TCF-1 limits intraepithelial lymphocyte antitumor immunity in colorectal carcinoma.
A spatially mapped gene expression signature for intestinal stem-like cells identifies high-risk precursors of gastric cancer.
Characterization and optimization of variability in a human colonic epithelium culture model.
p53 and MYC-regulated squalene epoxidase as Achilles heel in colorectal cancer.
Hypoxia induced deregulation of sphingolipids in colon cancer is a prognostic marker for patient outcome.
Intracellular FGF1 protects cells from apoptosis through direct interaction with p53.

Nat Commun. 2023 09 30. 14(1): 6109

IFNγ-Stat1 axis drives aging-associated loss of intestinal tissue homeostasis and regeneration.

Omid Omrani, Anna Krepelova, Seyed Mohammad Mahdi Rasa, Dovydas Syrvinskas, Jing Lu, Francesco Annunziata, George Garside, Seerat Bajwa, Susanne Reinhardt, Lisa Adam, Sandra Käppel, Nadia Ducano, Daniela Donna, Alessandro Ori, Salvatore Oliviero, Karl Lenhard Rudolph, Francesco Neri.

The influence of aging on intestinal stem cells and their niche can explain underlying causes for perturbation in their function observed during aging. Molecular mechanisms for such a decrease in the functionality of intestinal stem cells during aging remain largely undetermined. Using transcriptome-wide approaches, our study demonstrates that aging intestinal stem cells strongly upregulate antigen presenting pathway genes and over-express secretory lineage marker genes resulting in lineage skewed differentiation into the secretory lineage and strong upregulation of MHC class II antigens in the aged intestinal epithelium. Mechanistically, we identified an increase in proinflammatory cells in the lamina propria as the main source of elevated interferon gamma (IFNγ) in the aged intestine, that leads to the induction of Stat1 activity in intestinal stem cells thus priming the aberrant differentiation and elevated antigen presentation in epithelial cells. Of note, systemic inhibition of IFNγ-signaling completely reverses these aging phenotypes and reinstalls regenerative capacity of the aged intestinal epithelium.

DOI: https://doi.org/10.1038/s41467-023-41683-y
JCO Precis Oncol. 2023 Sep;7 e2300255

Predictive Impact of RNF43 Mutations in Patients With Proficient Mismatch Repair/Microsatellite Stable BRAFV600E-Mutated Metastatic Colorectal Cancer Treated With Target Therapy or Chemotherapy.

Roberto Moretto, Marco Maria Germani, Javier Ros, Francesca Daniel, Filippo Ghelardi, Guglielmo Vetere, Mirella Giordano, Rodrigo De Almeida Toledo, Francesca Bergamo, Giovanni Randon, Elena Elez, Sara Lonardi, Filippo Pietrantonio, Paola Vignali, Daniele Rossini, Judit Matito, Clara Ugolini, Gabriella Fontanini, Gianluca Masi, Chiara Cremolini.

PURPOSE: Target therapy (TT) with encorafenib plus cetuximab is a standard option in patients with BRAFV600E-mutated (mut) pretreated metastatic colorectal cancer (mCRC). Recently, mutations in RNF43, encoding a negative regulator of the WNT pathway, were associated with longer progression-free survival (PFS) and overall survival (OS) in patients with proficient mismatch repair/microsatellite stable (pMMR/MSS) BRAFV600E-mut mCRC treated with TT. Here, we explored the effect of RNF43 mutations on the efficacy of second-line TT versus standard chemotherapy (CT).METHODS: A retrospective cohort of patients with pMMR/MSS BRAFV600E-mut tumors, available RNF43 mutational status, and treated with second-line TT or oxaliplatin- and/or irinotecan-based CT was analyzed.
RESULTS: One hundred thirty-two patients with pMMR/MSS BRAFV600E-mut mCRC were included. RNF43 was found mut in 34 (26%) cases. Among RNF43 mutants, TT was associated with longer PFS (7.7 v 3.0 months; P = .002) and higher overall response rate (ORR; 45% v 0%; P = .009) compared with CT. Conversely, among RNF43 wild-type (wt) patients, only a trend for longer PFS (4.5 v 3.7 months; P = .064) favoring TT, with no differences in ORR (P = .14), was observed. After excluding 36 patients receiving TT in third line or beyond, a longer OS (19.4 v 10.1 months; P = .022) and a numerically OS advantage (10.6 v 6.6 months; P = .068) were reported for TT both in the RNF43-mut and in the RNF43 wt groups. However, no interaction effect was reported between RNF43 mutational status and treatment in ORR (Pinteraction = .96), PFS (Pinteraction = .13), and OS (Pinteraction = .44).
CONCLUSION: Patients with pMMR/MSS BRAFV600E-mut mCRC achieve benefit from TT versus CT independently of RNF43 mutational status, although a higher magnitude of benefit from TT is observed in RNF43-mut tumors. These findings deserve confirmation in concluded and ongoing randomized trials.

DOI: https://doi.org/10.1200/PO.23.00255
Am J Physiol Gastrointest Liver Physiol. 2023 Oct 03.

Intestinal-specific Hdac3 deletion increases susceptibility to colitis and small intestinal tumour development in mice fed a high fat diet.

Irvin Ng, Ian Y Luk, Rebecca Nightingale, Camilla M Reehorst, Mercedes Davalos-Salas, Laura J Jenkins, Chun Fong, David S Williams, Matthew J Watt, Amardeep S Dhillon, John M Mariadason.

  High fat diets, and inflammation are risk factors for colon cancer, however the underlying mechanisms remain to be fully elucidated. The transcriptional co-repressor HDAC3 has recently emerged as a key regulator of intestinal epithelial responses to diet and inflammation with intestinal-specific Hdac3 deletion (Hdac3IKO) in mice increasing lipid oxidation genes and the rate of lipid oxidation in enterocytes. Hdac3IKO mice are also predisposed to experimentally induced colitis, however whether this is driven by the intestinal metabolic reprogramming, and whether this predisposes these mice to intestinal tumourigenesis is unknown. Herein, we examined the effects of intestinal-specific Hdac3 deletion on colitis-associated intestinal tumourigenesis in mice fed a standard (STD) or HF diet (HFD). Hdac3IKO mice were highly prone to experimentally induced colitis, which was further enhanced by a HFD. Hdac3deletion also accelerated intestinal tumour development, specifically when fed a HFD and most notably in the small intestine where lipid absorption is maximal. Expression of proteins involved in fatty acid metabolism and oxidation (SCD1, EHHADH) were elevated in the small intestine of Hdac3IKO mice fed a HFD, and these mice displayed increased levels of lipid peroxidation, DNA damage, and apoptosis in their villi, as well as extensive expansion of the stem cell and progenitor cell compartment. These findings reveal a novel role for Hdac3 in suppressing colitis and intestinal tumorigenesis, particularly in the context of consumption of a HFD, and reveal a potential mechanism by which HFDs may increase intestinal tumorigenesis by increasing lipid oxidation, DNA damage and intestinal epithelial cell turnover.

Keywords:  AOM/DSS; HDAC3; colon; high fat diet; intestine

DOI:  https://doi.org/10.1152/ajpgi.00160.2023
Front Cell Dev Biol. 2023 ;11 1176657

Mechanisms of resistance to EGFR-targeted therapies in colorectal cancer: more than just genetics.

Christine Parseghian, Madhulika Eluri, Scott Kopetz, Kanwal Raghav.

  The development of acquired resistance to anti-EGFR therapies remains poorly understood, with most research to date exploring, and trying to overcome, various genomic mechanisms of resistance. However, recent work supports a model of resistance whereby transcriptomic mechanisms of resistance predominate in the presence of active cytotoxic chemotherapy combined with anti-EGFR therapy in the first-line setting, with a greater predominance of acquired MAPK mutations after single-agent anti-EGFR therapy in the later-line setting. The proposed model has implications for prospective studies evaluating anti-EGFR rechallenge strategies guided by acquired MAPK mutations and highlights the need to address transcriptional mechanisms of resistance.

Keywords:  anti-EGFR; anti-EGFR rechallenge; anti-EGFR resistance; genomic mechanisms of resistance to anti-EGFR; non-genomic mechanisms of resistance to anti-EGFR

DOI:  https://doi.org/10.3389/fcell.2023.1176657
Am J Physiol Gastrointest Liver Physiol. 2023 Oct 03.

Transcriptional Regulation of Metabolism in the Intestinal Epithelium.

Joseph Burclaff.

  Epithelial metabolism in the intestine is increasingly known to be important for stem cell maintenance and activity while also affecting weight gain and diseases. This review compiles studies from recent years which describe major transcriptional factors controlling metabolic activity across the intestinal epithelium as well as transcriptional and epigenetic networks controlling the factors themselves. Recent studies show that transcriptional regulators serve as the link between signals from the microbiota and diet and epithelial metabolism. Studies have advanced this paradigm to identify druggable targets to block weight gain or disease progression in mice. As such, there is great potential that a better understanding of these regulatory networks will improve our knowledge of intestinal physiology and promote discoveries to benefit human health.

Keywords:  intestinal epithelium; intestinal metabolism; transcription factors

DOI:  https://doi.org/10.1152/ajpgi.00147.2023
Cancer Metastasis Rev. 2023 Oct 05.

Cancer cell plasticity, stem cell factors, and therapy resistance: how are they linked?

Homa Fatma, Hifzur R Siddique.

  Cellular plasticity can occur naturally in an organism and is considered an adapting mechanism during the developmental stage. However, abnormal cellular plasticity is observed in different diseased conditions, including cancer. Cancer cell plasticity triggers the stimuli of epithelial-mesenchymal transition (EMT), abnormal epigenetic changes, expression of stem cell factors and implicated signaling pathways, etc., and helps in the maintenance of CSC phenotype. Conversely, CSC maintains the cancer cell plasticity, EMT, and epigenetic plasticity. EMT contributes to increased cell migration and greater diversity within tumors, while epigenetic changes, stem cell factors (OCT4, NANOG, and SOX2), and various signaling pathways allow cancer cells to maintain various phenotypes, giving rise to intra- and inter-tumoral heterogeneity. The intricate relationships between cancer cell plasticity and stem cell factors help the tumor cells adopt drug-tolerant states, evade senescence, and successfully acquire drug resistance with treatment dismissal. Inhibiting molecules/signaling pathways involved in promoting CSCs, cellular plasticity, EMT, and epigenetic plasticity might be helpful for successful cancer therapy management. This review discussed the role of cellular plasticity, EMT, and stem cell factors in tumor initiation, progression, reprogramming, and therapy resistance. Finally, we discussed how the intervention in this axis will help better manage cancers and improve patient survivability.

Keywords:  Cancer stem cells; Cellular plasticity; Drug resistance; Epigenetic plasticity; Epithelial-mesenchymal transition

DOI:  https://doi.org/10.1007/s10555-023-10144-9
Oncotarget. 2023 10 04. 14 879-889

Inhibiting BRAF/EGFR/MEK suppresses cancer stemness and drug resistance of primary colorectal cancer cells.

Astha Lamichhane, Gary D Luker, Seema Agarwal, Hossein Tavana.

  Drug resistance is a major barrier against successful treatments of cancer patients. Gain of stemness under drug pressure is a major mechanism that renders treatments ineffective. Identifying approaches to target cancer stem cells (CSCs) is expected to improve treatment outcomes for patients. To elucidate the role of cancer stemness in resistance of colorectal cancer cells to targeted therapies, we developed spheroid cultures of patient-derived BRAFmut and KRASmut tumor cells and studied resistance mechanisms to inhibition of MAPK pathway through phenotypic and gene and protein expression analysis. We found that treatments enriched the expression of CSC markers CD166, ALDH1A3, CD133, and LGR5 and activated PI3K/Akt pathway in cancer cells. We examined various combination treatments to block these activities and found that a triple combination against BRAF, EGFR, and MEK significantly reduced stemness and activities of oncogenic signaling pathways. This study demonstrates the feasibility of blocking stemness-mediated drug resistance and tumorigenic activities in colorectal cancer.

Keywords:  cancer stem cells; colorectal cancer; combination treatment; drug resistance; patient-derived tumor model

DOI:  https://doi.org/10.18632/oncotarget.28517
Cell Host Microbe. 2023 Sep 28. pii: S1931-3128(23)00369-4. [Epub ahead of print]

An early-life microbiota metabolite protects against obesity by regulating intestinal lipid metabolism.

Catherine D Shelton, Elizabeth Sing, Jessica Mo, Nicolas G Shealy, Woongjae Yoo, Julia Thomas, Gillian N Fitz, Pollyana R Castro, Tara T Hickman, Teresa P Torres, Nora J Foegeding, Jacob K Zieba, M Wade Calcutt, Simona G Codreanu, Stacy D Sherrod, John A McLean, Sun H Peck, Fan Yang, Nicholas O Markham, Min Liu, Mariana X Byndloss.

  The mechanisms by which the early-life microbiota protects against environmental factors that promote childhood obesity remain largely unknown. Using a mouse model in which young mice are simultaneously exposed to antibiotics and a high-fat (HF) diet, we show that Lactobacillus species, predominant members of the small intestine (SI) microbiota, regulate intestinal epithelial cells (IECs) to limit diet-induced obesity during early life. A Lactobacillus-derived metabolite, phenyllactic acid (PLA), protects against metabolic dysfunction caused by early-life exposure to antibiotics and a HF diet by increasing the abundance of peroxisome proliferator-activated receptor γ (PPAR-γ) in SI IECs. Therefore, PLA is a microbiota-derived metabolite that activates protective pathways in the small intestinal epithelium to regulate intestinal lipid metabolism and prevent antibiotic-associated obesity during early life.

Keywords:  Lactobacillus; antibiotics; arachnoid barrier; brain fibroblasts; early-life; intestinal epithelium; leptomeninges; metabolism; microbiota; obesity; single-cell RNA sequencing; tricellular junction

DOI:  https://doi.org/10.1016/j.chom.2023.09.002
bioRxiv. 2023 Sep 22. pii: 2023.09.20.558726. [Epub ahead of print]

Epithelial zonation along the mouse and human small intestine defines five discrete metabolic domains.

Rachel K Zwick, Petr Kasparek, Brisa Palikuqi, Sara Viragova, Laura Weichselbaum, Christopher S McGinnis, Kara L McKinley, Asoka Rathnayake, Dedeepya Vaka, Vinh Nguyen, Coralie Trentesaux, Efren Reyes, Alexander R Gupta, Zev J Gartner, Richard M Locksley, James M Gardner, Shalev Itzkovitz, Dario Boffelli, Ophir D Klein.

A key aspect of nutrient absorption is the exquisite division of labor across the length of the small intestine, with individual classes of micronutrients taken up at different positions. For millennia, the small intestine was thought to comprise three segments with indefinite borders: the duodenum, jejunum, and ileum. By examining fine-scale longitudinal segmentation of the mouse and human small intestines, we identified transcriptional signatures and upstream regulatory factors that define five domains of nutrient absorption, distinct from the three traditional sections. Spatially restricted expression programs were most prominent in nutrient-absorbing enterocytes but initially arose in intestinal stem cells residing in three regional populations. While a core signature was maintained across mice and humans with different diets and environments, domain properties were influenced by dietary changes. We established the functions of Ppar-ẟ and Cdx1 in patterning lipid metabolism in distal domains and generated a predictive model of additional transcription factors that direct domain identity. Molecular domain identity can be detected with machine learning, representing the first systematic method to computationally identify specific intestinal regions in mice. These findings provide a foundational framework for the identity and control of longitudinal zonation of absorption along the proximal:distal small intestinal axis.

DOI: https://doi.org/10.1101/2023.09.20.558726
Cancer Sci. 2023 Sep 30.

DYRK2 promotes chemosensitivity via p53-mediated apoptosis after DNA damage in colorectal cancer.

Yasuhiro Takano, Satomi Yogosawa, Yuta Imaizumi, Hiroshi Kamioka, Yumi Kanegae, Ken Eto, Kiyotsugu Yoshida.

  Dual-specificity tyrosine-regulated kinase 2 (DYRK2) is a protein kinase that phosphorylates p53-Ser46 and induces apoptosis in response to DNA damage. However, the relationship between DYRK2 expression and chemosensitivity after DNA damage in colorectal cancer has not been well investigated. The aim of the present study was to examine whether DYRK2 could be a novel marker for predicting chemosensitivity after 5-fluorouracil- and oxaliplatin-induced DNA damage in colorectal cancer. Here we showed that DYRK2 knockout decreased the chemosensitivity to 5-fluorouracil and oxaliplatin in p53 wild-type colorectal cancer cells, whereas the chemosensitivity remained unchanged in p53-deficient/mutated colorectal cancer cells. In addition, no significant differences in chemosensitivity to 5-fluorouracil and oxaliplatin between scramble and siDYRK2 p53(-/-) colorectal cancer cells were observed. Conversely, the combination of adenovirus-mediated overexpression of DYRK2 with 5-fluorouracil or oxaliplatin enhanced apoptosis and chemosensitivity through p53-Ser46 phosphorylation in p53 wild-type colorectal cancer cells. Furthermore, DYRK2 knockout decreased chemosensitivity to 5-fluorouracil and oxaliplatin in p53 wild-type xenograft mouse models. Taken together, these findings demonstrated that DYRK2 expression was associated with chemosensitivity to 5-fluorouracil and oxaliplatin in p53 wild-type colorectal cancer, suggesting the importance of evaluating the p53 status and DYRK2 expression as a novel marker in therapeutic strategies for colorectal cancer.

Keywords:  DNA damage; chemosensitivity; colorectal cancer; dual-specificity tyrosine-regulated kinase 2; p53

DOI:  https://doi.org/10.1111/cas.15973
Int J Food Sci Nutr. 2023 Sep 27. 1-16

Dietary regulation of intestinal stem cells in health and disease.

Hancheng Fan, Jiaqiang Wu, Kangping Yang, Chaoyi Xiong, Siyi Xiong, Xingwu Wu, Zheng Fang, Jing Zhu, Jialyu Huang.

  Diet is a critical regulator for physiological metabolism and tissue homeostasis, with a close relation to health and disease. As an important organ for digestion and absorption, the intestine comes into direct contact with many dietary components. The rapid renewal of its mucosal epithelium depends on the continuous proliferation and differentiation of intestinal stem cells (ISCs). The function and metabolism of ISCs can be controlled by a variety of dietary patterns including calorie restriction, fasting, high-fat, ketogenic, and high-sugar diets, as well as different nutrients including vitamins, amino acids, dietary fibre, and probiotics. Therefore, dietary interventions targeting ISCs may make it possible to prevent and treat intestinal disorders such as colon cancer, inflammatory bowel disease, and radiation enteritis. This review summarised recent research on the role and mechanism of diet in regulating ISCs, and discussed the potential of dietary modulation for intestinal diseases.

Keywords:  Intestinal stem cell; diet; nutrient; regulation; signalling pathway

DOI:  https://doi.org/10.1080/09637486.2023.2262780
Sci Immunol. 2023 Oct 13. 8(88): eadf2163

TCF-1 limits intraepithelial lymphocyte antitumor immunity in colorectal carcinoma.

Marina H Yakou, Sonia Ghilas, Kelly Tran, Yang Liao, Shoukat Afshar-Sterle, Anita Kumari, Kevin Schmid, Christine Dijkstra, Chantelle Inguanti, Simone Ostrouska, Jordan Wilcox, Maxine Smith, Pavitha Parathan, Amr Allam, Hai-Hui Xue, Gabrielle T Belz, John M Mariadason, Andreas Behren, Grant R Drummond, Roland Ruscher, David S Williams, Bhupinder Pal, Wei Shi, Matthias Ernst, Dinesh Raghu, Lisa A Mielke.

Intraepithelial lymphocytes (IELs), including αβ and γδ T cells (T-IELs), constantly survey and play a critical role in maintaining the gastrointestinal epithelium. We show that cytotoxic molecules important for defense against cancer were highly expressed by T-IELs in the small intestine. In contrast, abundance of colonic T-IELs was dependent on the microbiome and displayed higher expression of TCF-1/TCF7 and a reduced effector and cytotoxic profile, including low expression of granzymes. Targeted deletion of TCF-1 in γδ T-IELs induced a distinct effector profile and reduced colon tumor formation in mice. In addition, TCF-1 expression was significantly reduced in γδ T-IELs present in human colorectal cancers (CRCs) compared with normal healthy colon, which strongly correlated with an enhanced γδ T-IEL effector phenotype and improved patient survival. Our work identifies TCF-1 as a colon-specific T-IEL transcriptional regulator that could inform new immunotherapy strategies to treat CRC.

DOI: https://doi.org/10.1126/sciimmunol.adf2163
bioRxiv. 2023 Sep 22. pii: 2023.09.20.558462. [Epub ahead of print]

A spatially mapped gene expression signature for intestinal stem-like cells identifies high-risk precursors of gastric cancer.

Robert J Huang, Ignacio A Wichmann, Andrew Su, Anuja Sathe, Miranda V Shum, Susan M Grimes, Rithika Meka, Alison Almeda, Xiangqi Bai, Jeanne Shen, Quan Nguyen, Manuel R Amieva, Joo Ha Hwang, Hanlee P Ji.

Objective: Gastric intestinal metaplasia ( GIM ) is a precancerous lesion that increases gastric cancer ( GC ) risk. The Operative Link on GIM ( OLGIM ) is a combined clinical-histopathologic system to risk-stratify patients with GIM. The identification of molecular biomarkers that are indicators for advanced OLGIM lesions may improve cancer prevention efforts.Methods: This study was based on clinical and genomic data from four cohorts: 1) GAPS, a GIM cohort with detailed OLGIM severity scoring (N=303 samples); 2) the Cancer Genome Atlas (N=198); 3) a collation of in-house and publicly available scRNA-seq data (N=40), and 4) a spatial validation cohort (N=5) consisting of annotated histology slides of patients with either GC or advanced GIM. We used a multi-omics pipeline to identify, validate and sequentially parse a highly-refined signature of 26 genes which characterize high-risk GIM.
Results: Using standard RNA-seq, we analyzed two separate, non-overlapping discovery (N=88) and validation (N=215) sets of GIM. In the discovery phase, we identified 105 upregulated genes specific for high-risk GIM (defined as OLGIM III-IV), of which 100 genes were independently confirmed in the validation set. Spatial transcriptomic profiling revealed 36 of these 100 genes to be expressed in metaplastic foci in GIM. Comparison with bulk GC sequencing data revealed 26 of these genes to be expressed in intestinal-type GC. Single-cell profiling resolved the 26-gene signature to both mature intestinal lineages (goblet cells, enterocytes) and immature intestinal lineages (stem-like cells). A subset of these genes was further validated using single-molecule multiplex fluorescence in situ hybridization. We found certain genes ( TFF3 and ANPEP ) to mark differentiated intestinal lineages, whereas others ( OLFM4 and CPS1 ) localized to immature cells in the isthmic/crypt region of metaplastic glands, consistent with the findings from scRNAseq analysis.
Conclusions: using an integrated multi-omics approach, we identified a novel 26-gene expression signature for high-OLGIM precursors at increased risk for GC. We found this signature localizes to aberrant intestinal stem-like cells within the metaplastic microenvironment. These findings hold important translational significance for future prevention and early detection efforts.

DOI: https://doi.org/10.1101/2023.09.20.558462
bioRxiv. 2023 Sep 22. pii: 2023.09.22.559007. [Epub ahead of print]

Characterization and optimization of variability in a human colonic epithelium culture model.

Colleen M Pike, Bailey Zwarycz, Bryan E McQueen, Mariana Castillo, Catherine Barron, Jeremy M Morowitz, James A Levi, Dhiral Phadke, Michele Balik-Meisner, Deepak Mav, Ruchir Shah, Danielle L Cunningham Glasspoole, Ron Laetham, William Thelin, Maureen K Bunger, Elizabeth M Boazak.

Animal models have historically been poor preclinical predictors of gastrointestinal (GI) directed therapeutic efficacy and drug-induced GI toxicity. Human stem and primary cell-derived culture systems are a major focus of efforts to create biologically relevant models that enhance preclinical predictive value of intestinal efficacy and toxicity. The inherent variability in stem-cell-based complex cultures makes development of useful models a challenge; the stochastic nature of stem-cell differentiation interferes with the ability to build and validate robust, reproducible assays that query drug responses and pharmacokinetics. In this study, we aimed to characterize and reduce potential sources of variability in a complex stem cell-derived intestinal epithelium model, termed RepliGut ® Planar, across cells from multiple human donors, cell lots, and passage numbers. Assessment criteria included barrier formation and integrity, gene expression, and cytokine responses. Gene expression and culture metric analyses revealed that controlling for stem/progenitor-cell passage number reduces variability and maximizes physiological relevance of the model. After optimizing passage number, donor-specific differences in cytokine responses were observed in a case study, suggesting biologic variability is observable in cell cultures derived from multiple human sources. Our findings highlight key considerations for designing assays that can be applied to additional primary-cell derived systems, as well as establish utility of the RepliGut ® Planar platform for robust development of human-predictive drug-response assays.

DOI: https://doi.org/10.1101/2023.09.22.559007
Int J Biol Sci. 2023 ;19(15): 4831-4832

p53 and MYC-regulated squalene epoxidase as Achilles heel in colorectal cancer.

Martin Fischer.

  The transcription factors p53 and MYC are often considered non-druggable targets, but their dysregulation can generate new dependencies and treatment opportunities in cancer cells. The p53 and MYC-regulated squalene epoxidase (SQLE) has been identified as a potential Achilles heel in colorectal cancer. This is of great interest because the FDA-approved anti-fungal SQLE inhibitor Terbinafine could be repurposed to treat colorectal cancer patients.

Keywords:  SQLE; Terbinafine; cholesterol synthesis; colorectal cancer; transcription factor MYC; tumor suppressor p53

DOI:  https://doi.org/10.7150/ijbs.89237
Biochim Biophys Acta Mol Basis Dis. 2023 Oct 04. pii: S0925-4439(23)00272-7. [Epub ahead of print] 166906

Hypoxia induced deregulation of sphingolipids in colon cancer is a prognostic marker for patient outcome.

Khadija El Hindi, Sebastian Brachtendorf, Jennifer C Hartel, Christoph Renné, Kerstin Birod, Karin Schilling, Sandra Labocha, Dominique Thomas, Nerea Ferreirós, Lisa Hahnefeld, Erika Dorochow, Domenico Del Turco, Thomas Deller, Klaus Scholich, Dominik C Fuhrmann, Andreas Weigert, Bernhard Brüne, Gerd Geisslinger, Ilka Wittig, Karl-Heinrich Link, Sabine Grösch.

  Sphingolipids are important for the physicochemical properties of cellular membranes and deregulated in tumors. In human colon cancer tissue ceramide synthase (CerS) 4 and CerS5 are reduced which correlates with a reduced survival probability of late-stage colon cancer patients. Both enzymes are reduced after hypoxia in advanced colorectal cancer (CRC) cells (HCT-116, SW620) but not in non-metastatic CRC cells (SW480, Caco-2). Downregulation of CerS4 or CerS5 in advanced CRC cells enhanced tumor formation in nude mice and organoid growth in vitro. This was accompanied by an enhanced proliferation rate and metabolic changes leading to a shift towards the Warburg effect. In contrast, CerS4 or CerS5 depletion in Caco-2 cells reduced tumor growth in vivo. Lipidomic and proteomic analysis of membrane fractions revealed significant changes in tumor-promoting cellular pathways and cellular transporters. This study identifies CerS4 and CerS5 as prognostic markers for advanced colon cancer patients and provides a comprehensive overview about the associated cellular metabolic changes. We propose that the expression level of CerS4 and CerS5 in colon tumors could serve as a basis for decision-making for personalized treatment of advanced colon cancer patients. Trial registration: The study was accredited by the study board of the Deutsche Krebsgesellschaft (Registration No: St-D203, 2017/06/30, retrospectively registered).

Keywords:  Biomarker; Lipidomic; Metabolism; Oxidative consumption rate, hypoxia; Proteomic

DOI:  https://doi.org/10.1016/j.bbadis.2023.166906
Cell Mol Life Sci. 2023 Oct 02. 80(10): 311

Intracellular FGF1 protects cells from apoptosis through direct interaction with p53.

Agata Lampart, Daniel Krowarsch, Martyna Biadun, Vigdis Sorensen, Jakub Szymczyk, Katarzyna Sluzalska, Antoni Wiedlocha, Jacek Otlewski, Malgorzata Zakrzewska.

  Fibroblast growth factor 1 (FGF1) acts by activating specific tyrosine kinase receptors on the cell surface. In addition to this classical mode of action, FGF1 also exhibits intracellular activity. Recently, we found that FGF1 translocated into the cell interior exhibits anti-apoptotic activity independent of receptor activation and downstream signaling. Here, we show that expression of FGF1 increases the survival of cells treated with various apoptosis inducers, but only when wild-type p53 is present. The p53-negative cells were not protected by either ectopically expressed or translocated FGF1. We also confirmed the requirement of p53 for the anti-apoptotic intracellular activity of FGF1 by silencing p53, resulting in loss of the protective effect of FGF1. In contrast, in p53-negative cells, intracellular FGF1 regained its anti-apoptotic properties after transfection with wild-type p53. We also found that FGF1 directly interacts with p53 in cells and that the binding region is located in the DBD domain of p53. We therefore postulate that intracellular FGF1 protects cells from apoptosis by directly interacting with p53.

Keywords:  Anti-apoptotic activity; Apoptosis; Fibroblast growth factor 1 (FGF1); Intracellular function; Protein–protein interaction; p53

DOI:  https://doi.org/10.1007/s00018-023-04964-9