Correction: Gresseau et al. A Signaling Crosstalk Links SNAIL to the 37/67 kDa Laminin-1 Receptor Ribosomal Protein SA and Regulates the Acquisition of a Cancer Stem Cell Molecular Signature in U87 Glioblastoma Neurospheres. Cancers 2022, 14, 5944.

In the original publication [...].

A molecular signature for the G6PC3/SLC37A2/SLC37A4 interactors in glioblastoma disease progression and in the acquisition of a brain cancer stem cell phenotype.

Background: Glycogen plays an important role in glucose homeostasis and contributes to key functions related to brain cancer cell survival in glioblastoma multiforme (GBM) disease progression. Such adaptive molecular mechanism is dependent on the glycogenolytic pathway and intracellular glucose-6-phosphate (G6P) sensing by brain cancer cells residing within those highly hypoxic tumors. The involvement of components of the glucose-6-phosphatase (G6Pase) system remains however elusive. Objective: We questioned the gene expression levels of components of the G6Pase system in GBM tissues and their functional impact in the control of the invasive and brain cancer stem cells (CSC) phenotypes. Methods: In silico analysis of transcript levels in GBM tumor tissues was done by GEPIA. Total RNA was extracted and gene expression of G6PC1-3 as well as of SLC37A1-4 members analyzed by qPCR in four human brain cancer cell lines and from clinically annotated brain tumor cDNA arrays. Transient siRNA-mediated gene silencing was used to assess the impact of TGF-ß-induced epithelial-to-mesenchymal transition (EMT) and cell chemotaxis. Three-dimensional (3D) neurosphere cultures were generated to recapitulate the brain CSC phenotype. Results: Higher expression in G6PC3, SLC37A2, and SLC37A4 was found in GBM tumor tissues in comparison to low-grade glioma and healthy tissue. The expression of these genes was also found elevated in established human U87, U251, U118, and U138 GBM cell models compared to human HepG2 hepatoma cells. SLC37A4/G6PC3, but not SLC37A2, levels were induced in 3D CD133/SOX2-positive U87 neurospheres when compared to 2D monolayers. Silencing of SLC37A4/G6PC3 altered TGF-ß-induced EMT biomarker SNAIL and cell chemotaxis. Conclusion: Two members of the G6Pase system, G6PC3 and SLC37A4, associate with GBM disease progression and regulate the metabolic reprogramming of an invasive and CSC phenotype. Such molecular signature may support their role in cancer cell survival and chemoresistance and become future therapeutic targets.

EGCG inhibits the inflammation and senescence inducing properties of MDA-MB-231 triple-negative breast cancer (TNBC) cells-derived extracellular vesicles in human adipose-derived mesenchymal stem cells.

BACKGROUND: Triple-negative breast cancer (TNBC) cells' secretome can induce a pro-inflammatory phenotype in human adipose-derived mesenchymal stem cells (hADMSC). This can be prevented by the green tea polyphenol epigallocatechin-3-gallate (EGCG). The impact of EGCG on the paracrine regulation that the extracellular vesicles (EVs) specifically exert within the TNBC secretome remains unknown. METHODS: EVs were obtained from a TNBC-derived serum-starved MDA-MB-231 cell model treated or not with EGCG under normoxic or hypoxic (< 1% O2) culture conditions. RNA-Seq analysis was used to assess the EVs' genetic content. The modulation of inflammatory and senescence markers in hADMSC was evaluated by RT-qPCR using cDNA arrays and validated by immunoblotting. A protein profiler phospho-kinase array was used to explore signaling pathways. RESULTS: While hypoxic culture conditions did not significantly alter the genetic content of MDA-MB-231-secreted EVs, the addition of EGCG significantly modified EVs genetic material at low oxygen tension. Gene expression of cancer-associated adipocyte pro-inflammatory markers CXCL8, CCL2 and IL-1ß was increased in hADMSC treated with EVs. Concomitantly, EVs isolated from MDA-MB-231 treated with EGCG (EGCG-EVs) downregulated CCL2 and IL-1ß, while inducing higher expression of CXCL8 and IL-6 levels. EVs activated CHK-2, c-Jun, AKT and GSK-3ß signaling pathways in hADMSC, whereas EGCG-EVs specifically reduced the latter two as well as the serum starvation-induced senescence markers p21 and ß-galactosidase. Finally, the mitochondrial content within the TNBC cells-derived EVs was found reduced upon EGCG treatment. CONCLUSION: This proof of concept study demonstrates that the chemopreventive properties of diet-derived polyphenols may efficiently target the paracrine regulation that TNBC cells could exert upon their surrounding adipose tissue microenvironment.

The Montreal split ring applicator: Towards highly adaptive gynecological brachytherapy using 3D-printed biocompatible patient-specific interstitial caps.

Purpose: The addition of interstitial (IS) needles to intra-cavitary (IC) brachytherapy applicators is associated with improved outcomes in locally advanced cervical cancers involving parametrial tumor extensions. The purpose of this work was to validate a clinical workflow involving 3D-printed caps for a commercial IC split ring applicator that enable using IS needle trajectories tailored to each treatment. Material and methods: A dedicated software module was developed in this work allowing users to design patient-specific IS caps without knowledge of computer-aided design (CAD) software. This software module was integrated to 3D Brachy, a commercial software developed by Adaptiiv Medical Technologies Inc. For validation of the workflow, CAD models of ground truth caps with five IS needle trajectories were designed with Fusion 360™, 3D-printed, assembled with a split ring applicator, and CT-scanned with radio-opaque markers. 3D Brachy was then applied to generate a replica based on trajectories reconstructed from the radio-opaque markers. A comparison between ground truth and replicated IS needle trajectories was done using intersection points with planes at the level of the cervix (z = 0 cm) and a representative needle depth (z = 3 cm). Results: Prototypes of interstitial caps 3D-printed in both BioMed Amber and BioMed Clear SLA resins were tested to be functional both pre- and post-sterilization for IS needles with obliquity angles ≤ 45°. Distance-to-agreement at z = 0 cm and 3 cm as well as deviations in pitch and yaw angles of the five IS needle trajectories were found to have mean values of 3.3 ±2.1 mm, 7.3 ±2.0 mm, 2.9° ±2.3°, and 7.0° ±7.0°, respectively. Conclusions: The clinical workflow for image-guided adaptive cervical cancer brachytherapy using the Montreal split ring applicator was validated.

A Signaling Crosstalk Links SNAIL to the 37/67 kDa Laminin-1 Receptor Ribosomal Protein SA and Regulates the Acquisition of a Cancer Stem Cell Molecular Signature in U87 Glioblastoma Neurospheres.

Background: Three-dimensional in vitro neurospheres cultures recapitulate stemness features associated with poor clinical outcome in glioblastoma patients. They are commonly used to address brain cancer stem cell (CSC) signal transducing biology that regulates spheroids formation and stemness phenotype, and to assess the in vitro pharmacological impact of chemotherapeutic drugs. Objective: Here, we addressed the role of a new signaling axis involved in the regulation of in vitro spheroids formation and assessed the chemopreventive ability of diet-derived epigallocatechin gallate (EGCG) to impact the processes that govern the acquisition of spheroids CSC stemness traits. Methods: Neurospheres were generated from adherent human U87 glioblastoma cancer cell cultures under conditions that recapitulate stemness features. Total RNA and protein lysates were isolated for gene expression by RT-qPCR and protein expression by immunoblot. Transcriptomic analysis was performed through RNA-Seq. Results: Compared to their parental adherent cells, tumorspheres expressed increased levels of the CSC markers NANOG, SOX2, PROM1 (CD133), as well as of the epithelial-to-mesenchymal transition (EMT) markers Fibronectin, SNAI1, and 37/67 kDa laminin-1 receptor ribosomal protein SA (RPSA). Increased PROM1, SOX2, Fibronectin, and RPSA transcripts level were also observed in clinical grade IV glioblastoma tissues compared to normal tissue. EGCG treatment reduced dose-dependently tumorspheres size and inhibited the transcriptional regulation of those genes. An apoptotic signature was also found in spheroids with increased signal transducing events involving GSK3α/ß, RSK, and CREB. These were repressed upon RPSA gene silencing and partially by SNAI1 silencing. Conclusion: This work highlights a signaling axis linking RPSA upstream of SNAIL in neurospheres genesis and supports the chemopreventive impact that diet-derived EGCG may exert on the acquisition of CSC traits.

Toward enteral nutrition for the treatment of pediatric Crohn disease in Canada: a workshop to identify barriers and enablers.

The treatment armamentarium in pediatric Crohn disease (CD) is very similar to adult-onset CD with the notable exception of the use of exclusive enteral nutrition (EEN [the administration of a liquid formula diet while excluding normal diet]), which is used more frequently by pediatric gastroenterologists to induce remission. In pediatric CD, EEN is now recommended by the pediatric committee of the European Crohn's and Colitis Organisation and the European Society for Paediatric Gastroenterology Hepatology and Nutrition as a first-choice agent to induce remission, with remission rates in pediatric studies consistently >75%. To chart and address enablers and barriers of use of EEN in Canada, a workshop was held in September 2014 in Toronto (Ontario), inviting pediatric gastroenterologists, nurses and dietitians from most Canadian pediatric IBD centres as well as international faculty from the United States and Europe with particular research and clinical expertise in the dietary management of pediatric CD. Workshop participants ranked the exclusivity of enteral nutrition; the health care resources; and cost implications as the top three barriers to its use. Conversely, key enablers mentioned included: standardization and sharing of protocols for use of enteral nutrition; ensuring sufficient dietetic resources; and reducing the cost of EEN to the family (including advocacy for reimbursement by provincial ministries of health and private insurance companies). Herein, the authors report on the discussions during this workshop and list strategies to enhance the use of EEN as a treatment option in the treatment of pediatric CD in Canada.