Reduced expression of α-L-Fucosidase-1 (FUCA-1) predicts recurrence and shorter cancer specific survival in luminal B LN+ breast cancer patients

Mapping the topography of spatial gene expression with interpretable deep learning

Spatially resolved transcriptomics technologies provide high-throughput measurements of gene expression in a tissue slice, but the sparsity of this data complicates the analysis of spatial gene expression patterns such as gene expression gradients. We address these issues by deriving a topographic map of a tissue slice-analogous to a map of elevation in a landscape-using a novel quantity called the isodepth. Contours of constant isodepth enclose spatial domains with distinct cell type composition, while gradients of the isodepth indicate spatial directions of maximum change in gene expression. We develop GASTON, an unsupervised and interpretable deep learning algorithm that simultaneously learns the isodepth, spatial gene expression gradients, and piecewise linear functions of the isodepth that model both continuous gradients and discontinuous spatial variation in the expression of individual genes. We validate GASTON by showing that it accurately identifies spatial domains and marker genes across several biological systems. In SRT data from the brain, GASTON reveals gradients of neuronal differentiation and firing, and in SRT data from a tumor sample, GASTON infers gradients of metabolic activity and epithelial-mesenchymal transition (EMT)-related gene expression in the tumor microenvironment.

Human Platelet-Rich Plasma Regulates Canine Mesenchymal Stem Cell Migration through Aquaporins

Platelet products are commonly used in regenerative medicine due to their effects on the acceleration and promotion of wound healing, reduction of bleeding, synthesis of new connective tissue, and revascularization. Furthermore, a novel approach for the treatment of damaged tissues, following trauma or other pathological damages, is represented by the use of mesenchymal stem cells (MSCs). In dogs, both platelet-rich plasma (PRP) and MSCs have been suggested to be promising options for subacute skin wounds. However, the collection of canine PRP is not always feasible. In this study, we investigated the effect of human PRP (hPRP) on canine MSCs (cMSCs). We isolated cMSCs and observed that hPRP did not modify the expression levels of the primary class of major histocompatibility complex genes. However, hPRP was able to increase cMSC viability and migration by at least 1.5-fold. hPRP treatment enhanced both Aquaporin (AQP) 1 and AQP5 protein levels, and their inhibition by tetraethylammonium chloride led to a reduction of PRP-induced migration of cMSCs. In conclusion, we have provided evidence that hPRP supports cMSC survival and may promote cell migration, at least through AQP activation. Thus, hPRP may be useful in canine tissue regeneration and repair, placing as a promising tool for veterinary therapeutic approaches.

N-Linked glycosylation profiles of therapeutic induced senescent (TIS) triple negative breast cancer cells (TNBC) and their extracellular vesicle (EV) progeny

Triple negative breast cancer (TNBC) has poor clinical outcomes and limited treatment options. Chemotherapy, while killing some cancer cells, can result in therapeutic-induced-senescent (TIS) cells. Senescent cells release significantly more extracellular vesicles (EVs) than non-senescent cells. Recently, N- and O-linked glycosylation alterations have been associated with senescence. We aimed to profile the N-linked glycans of whole cells, membrane, cytoplasm and EVs harvested from TIS TNBC cells and to compare these to results from non-senescent cells. TIS was induced in the Cal51 TNBC cells using the chemotherapeutic agent paclitaxel (PTX). Ultra-performance liquid chromatography (UPLC) analysis of exoglycosidase digested N-linked glycans was carried out on TIS compared to non-treated control cells. LC-Mass spectrometry (MS) analysis of the N-linked glycans and lectin blotting of samples was carried out to confirm the UPLC results. Significant differences were found in the N-glycan profile of the Cal51 membrane, cytoplasm and EV progeny of TIS compared to non-senescent cells. Protein mass spectrometry showed that the TIS cells contain different glycan modifying enzymes. The lectin, calnexin demonstrated a lower kDa size (∼58 kDa) in TIS compared to control cells (∼90 kDa) while Galectin 3 demonstrated potential proteolytic cleavage with 32 kDa and ∼22 kDa bands evident in TIS compared to non-senescent control cells with a major 32 kDa band only. TIS CAL51 cells also demonstrated a reduced adhesion to collagen I compared to control non-senescent cells. This study has shown that therapeutic-induced-senescent TNBC cells and their EV progeny, display differential N-glycan moieties compared to non-senescent Cal51 cells and their resultant EV progeny. For the future, N-glycan moieties on cancer senescent cells and their EV progeny hold potential for (i) the monitoring of treatment response as a liquid biopsy, and (ii) cancer senescent cell targeting with lectin therapies.

High FUT3 expression is a marker of lower overall survival of breast cancer patients

The complex enzyme network responsible for glycan synthesis suffers significant changes during the first steps of tumor development, leading to the early formation of tumor-associated glycan signatures. Among the glycosylation pathways, changes in fucosylation emerged as one of most important features in cancer. Αlpha-1,3/4-fucosyltransferase (FUT3) has been linked to pro-tumor and anti-tumor pathways depending on the cancer type. The present study aimed to understand the gene and protein expression profiles of FUT3 in three different and independent cohorts composed by invasive breast cancer patients: Local Brazilian population, METABRIC and TCGA. FUT3 transcripts and protein were measured in the Brazilian population by real-time PCR and Western blotting, respectively. Clinical records and FUT3 levels from public METABRIC and TCGA cohorts were accessed through CBioPortal database. FUT3 expression was analyzed in each cohort using the appropriated statistic tools. Survival meta-analysis in triple negative patients was performed using five independent cohorts including GSE41119, GSE47994 and GSE86945, data obtained from GEO repository available at NCBI database, and METABRIC and TCGA. Our analysis showed that high FUT3 levels were consistently associated to reduced invasive breast cancer patients overall survival. This finding is particularly significant in triple negative patients. These results together with the previously knowledge regarding the involvement of FUT3 in pro-tumor and anti-tumor mechanisms led us to purpose a model for FUT3 expression regulation throughout breast cancer establishment and progression.

PI3K/AKT Signaling in Breast Cancer Molecular Subtyping and Lymph Node Involvement

Lymph node metastatic involvement persists to be among the most important predictors of recurrence and survival in breast carcinoma (BC). This study is aimed at investigating possible gene expression differences in primary BC between patients with or without lymph node involvement at the time of diagnosis. In a retrospective study, we investigated the potential prognostic role of 9 candidate biomarkers at the mRNA level in a cohort of 305 breast cancer patients, 151 lymph node-negative (LN-) and 154 lymph node-positive (LN+) individuals. The analyzed genes belonged to the RAS pathway (RAF1, ERBB2, PIK3CB, AKT1, AKT2, and AKT3), RB pathway (RB1 and CDK2), and cellular differentiation (KRT8). Their expression profiles were investigated by RT-qPCR and were correlated to immunohistochemically based molecular subtypes and BC clinical and pathological features. The differential expression of several genes in the primary tumor tissue was related to the LN involvement. Some of those genes, including PIK3CB, RB1, and AKT3, were more expressed in LN- BC patients, while some others, notably ERBB2 and AKT1, in LN+ ones. Among the candidate biomarkers, the expression levels of AKT isoforms influenced also patients' survival rates. In detail, higher expression levels of AKT1 and AKT2 negatively influenced overall patients' survival, and in particular, AKT2 expression levels defined a group of luminal B BC patients with shorter cancer-specific survival. On the contrary, longer cancer-specific survival was recorded in luminal A BC patients with higher expression levels of AKT3. That finding was also confirmed by Cox multivariate analysis. The same AKT3 resulted to be a possible candidate predictive biomarker for Tamoxifen response. In conclusion, our study highlighted the complex regulation of the PI3K/AKT pathway in BC and its differences in BC patients with and without lymph node involvement.

Plasma α-L-fucosidase-1 in patients with Sjögren's syndrome and other rheumatic disorders

BACKGROUND

Human α-fucosidase (EC 3.2.1.51) is a hydrolase the importance of which has been increasing in the latest years. However, data about its plasma level in children with autoimmune disorders, particularly Sjögren's syndrome (SS), are lacking. In this study, the plasma activity of L-α-fucosidase-1 (α-L-FUCA-1) was assayed in hospitalized children and adults and its association with SS and other rheumatic disorders further evaluated.

METHODS

In total 73 Hungarian hospitalized patients, 32 children (2.5-10 years) and 41 adults (32-68 years), were enrolled in the study and underwent plasma assay of α-L-FUCA1 activity. Linear regression, Durbin-Watson (DW), and Pearson tests were evaluated to investigate the relationship between α-L-FUCA-1 plasma levels and autoimmune manifestations.

RESULTS

α-L-FUCA-1 correlated with SS both in children (2-sided t test, P = 0.0023) and in adults (2-sided t test, P = 0.00035). Linear regressions showed that in other rheumatic disorders, α-L-FUCA1 did not show any differential distribution related to the particular pathology (r = 0.2042, P = 0.1531, DW test = 2.2139 positive), while this trend was radically opposite for patients with SS (r = 0.1462, P = 0.0032, DW test = 1.3664, negative).

CONCLUSIONS

Alterations in plasma level of α-L-FUCA-1 were significantly associated with SS. This preliminary result should encourage further research on α-L-FUCA-1 as a possible differential serological marker of SS.

Fucosylation in cancer biology and its clinical applications

Fucosylation is the process of transferring fucose from GDP-fucose to their substrates, which includes certain proteins, N- and O-linked glycans in glycoprotein or glycolipids, by fucosyltransferases in all mammalian cells. Fucosylated glycans play vital role in selectin-mediated leukocyte extravasation, lymphocyte homing, and pathogen-host interactions, whereas fucosylated proteins are essential for signaling transduction in numerous ontogenic events. Aberrant fucosylation due to the availability of high energy donor GDP-fucose, abnormal expression of FUTs and/or α-fucosidase, and the availability of their substrates leads to different fucosylated glycan or protein structures. Accumulating evidence demonstrates that aberrant fucosylation plays important role in all aspects of cancer biology. In this review, we will summarize the current knowledge about fucosylation in different physiological and pathological processes with a focus on their roles not only in cancer cell proliferation, invasion, and metastasis but also in tumor immune surveillance. Furthermore, the clinical potential and applications of fucosylation in cancer diagnosis and treatment will also be discussed.