Peritoneal colonization by human pancreatic cancer cells is inhibited by antisense FUT3 sequence

The new era of pancreatic cancer treatment: Application of nanotechnology breaking through bottlenecks

Since the advent of nanomedicine, physicians have harnessed these approaches for the prophylaxis, detection, and therapy of life-threatening diseases, particularly cancer. Nanoparticles have demonstrated notable efficacy in cancer therapy, showcasing the primary application of nanotechnology in targeted drug delivery. Pancreatic cancer stands out as the most lethal solid tumour in humans. The low survival rate is attributed to its highly aggressive nature, intrinsic resistance to chemotherapeutics, and the lack of successful therapies, compounded by delayed diagnosis due to nonspecific symptoms and the absence of rapid diagnostic strategies. Despite these challenges, nanotechnology-based carrier methods have been successfully employed in imaging and therapy approaches. Overcoming drug resistance in pancreatic cancer necessitates a comprehensive understanding of the microenvironment associated with the disease, paving the way for innovative nanocarriers. Hindered chemotherapy infiltration, attributed to inadequate vascularization and a dense tumour stroma, is a major hurdle that nanotechnology addresses. Intelligent delivery techniques, based on the Enhanced Permeability and Retention effect, form the basis of recently developed anticancer nanocarriers. These advancements aim to enhance drug accumulation in tumour locations, offering a potential solution to the treatment-resistant nature of cancer. Addressing the challenges in pancreatic cancer treatment demands innovative therapies, and the emergence of active nanocarriers presents a promising avenue for enhancing outcomes. This review specifically delves into the latest advancements in nanotechnology for the treatment of pancreatic cancer.

(Sialyl)Lewis Antigen Expression on Glycosphingolipids, N-, and O-Glycans in Colorectal Cancer Cell Lines is Linked to a Colon-Like Differentiation Program

Alterations in the glycomic profile are a hallmark of cancer, including colorectal cancer (CRC). While, the glycosylation of glycoproteins and glycolipids has been widely studied for CRC cell lines and tissues, a comprehensive overview of CRC glycomics is still lacking due to the usage of different samples and analytical methods. In this study, we compared glycosylation features of N-, O-glycans, and glycosphingolipid glycans for a set of 22 CRC cell lines, all measured by porous graphitized carbon nano-liquid chromatography-tandem mass spectrometry. An overall, high abundance of (sialyl)Lewis antigens for colon-like cell lines was found, while undifferentiated cell lines showed high expression of H blood group antigens and α2-3/6 sialylation. Moreover, significant associations of glycosylation features were found between the three classes of glycans, such as (sialyl)Lewis and H blood group antigens. Integration of the datasets with transcriptomics data revealed positive correlations between (sialyl)Lewis antigens, the corresponding glycosyltransferase FUT3 and transcription factors CDX1, ETS, HNF1/4A, MECOM, and MYB. This indicates a possible role of these transcription factors in the upregulation of (sialyl)Lewis antigens, particularly on glycosphingolipid glycans, via FUT3/4 expression in colon-like cell lines. In conclusion, our study provides insights into the possible regulation of glycans in CRC and can serve as a guide for the development of diagnostic and therapeutic biomarkers.

In-Depth Analysis of the N-Glycome of Colorectal Cancer Cell Lines

Colorectal cancer (CRC) is the third most commonly diagnosed cancer and the second leading cause of cancer deaths worldwide. A well-known hallmark of cancer is altered glycosylation. Analyzing the N-glycosylation of CRC cell lines may provide potential therapeutic or diagnostic targets. In this study, an in-depth N-glycomic analysis of 25 CRC cell lines was conducted using porous graphitized carbon nano-liquid chromatography coupled to electrospray ionization mass spectrometry. This method allows for the separation of isomers and performs structural characterization, revealing profound N-glycomic diversity among the studied CRC cell lines with the elucidation of a number of 139 N-glycans. A high degree of similarity between the two N-glycan datasets measured on the two different platforms (porous graphitized carbon nano-liquid chromatography electrospray ionization tandem mass spectrometry (PGC-nano-LC-ESI-MS) and matrix-assisted laser desorption/ionization time of flight-mass spectrometry (MALDI-TOF-MS)) was discovered. Furthermore, we studied the associations between glycosylation features, glycosyltransferases (GTs), and transcription factors (TFs). While no significant correlations between the glycosylation features and GTs were found, the association between TF CDX1 and (s)Le antigen expression and relevant GTs FUT3/6 suggests that CDX1 contributes to the expression of the (s)Le antigen through the regulation of FUT3/6. Our study provides a comprehensive characterization of the N-glycome of CRC cell lines, which may contribute to the future discovery of novel glyco-biomarkers of CRC.

Role of tumor cell sialylation in pancreatic cancer progression

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest malignancies and is currently the third leading cause of cancer death. The aggressiveness of PDAC stems from late diagnosis, early metastasis, and poor efficacy of current chemotherapies. Thus, there is an urgent need for effective biomarkers for early detection of PDAC and development of new therapeutic strategies. It has long been known that cellular glycosylation is dysregulated in pancreatic cancer cells, however, tumor-associated glycans and their cognate glycosylating enzymes have received insufficient attention as potential clinical targets. Aberrant glycosylation affects a broad range of pathways that underpin tumor initiation, metastatic progression, and resistance to cancer treatment. One of the prevalent alterations in the cancer glycome is an enrichment in a select group of sialylated glycans including sialylated, branched N-glycans, sialyl Lewis antigens, and sialylated forms of truncated O-glycans such as the sialyl Tn antigen. These modifications affect the activity of numerous cell surface receptors, which collectively impart malignant characteristics typified by enhanced cell proliferation, migration, invasion and apoptosis-resistance. Additionally, sialic acids on tumor cells engage inhibitory Siglec receptors on immune cells to dampen anti-tumor immunity, further promoting cancer progression. The goal of this review is to summarize the predominant changes in sialylation occurring in pancreatic cancer, the biological functions of sialylated glycoproteins in cancer pathogenesis, and the emerging strategies for targeting sialoglycans and Siglec receptors in cancer therapeutics.

A glycosyltransferase gene signature to detect pancreatic ductal adenocarcinoma patients with poor prognosis

Background

Pancreatic ductal adenocarcinoma (PDAC) is characterized by an important heterogeneity, reflected by different clinical outcomes and chemoresistance. During carcinogenesis, tumor cells display aberrant glycosylated structures, synthetized by deregulated glycosyltransferases, supporting the tumor progression. In this study, we aimed to determine whether PDAC could be stratified through their glycosyltransferase expression profiles better than the current binary classification (basal-like and classical) in order to improve detection of patients with poor prognosis.

Methods

Bioinformatic analysis of 169 glycosyltransferase RNA sequencing data were performed for 74 patient-derived xenografts (PDX) of resected and unresectable tumors. The Australian cohort of International Cancer Genome Consortium and the microarray dataset from Puleo patient's cohort were used as independent validation datasets.

Findings

New PDAC stratification based on glycosyltransferase expression profile allowed to distinguish different groups of patients with distinct clinical outcome (p-value = 0.007). A combination of 19 glycosyltransferases differentially expressed in PDX defined a glyco-signature, whose prognostic value was validated on datasets including resected whole tumor tissues. The glyco-signature was able to discriminate three clusters of PDAC patients on the validation cohorts, two clusters displaying a short overall survival compared to one cluster having a better prognosis. Both poor prognostic clusters having different glyco-profiles in Puleo patient's cohort were correlated with stroma activated or desmoplastic subtypes corresponding to distinct microenvironment features (p-value < 0.0001). Besides, differential expression and enrichment analyses revealed deregulated functional pathways specific to different clusters.

Interpretation

This study identifies a glyco-signature relevant for a prognostic use, potentially applicable to resected and unresectable PDAC. Furthermore, it provides new potential therapeutic targets.

Funding

This work was supported by INCa (Grants number 2018-078 and 2018-079), Fondation ARC (Grant number ARCPJA32020070002326), Cancéropôle PACA, DGOS (labelization SIRIC, Grant number 6038), Amidex Foundation and Ligue Nationale Contre le Cancer and by institutional fundings from INSERM and the Aix-Marseille Université.

Knockdown of α2,3-Sialyltransferases Impairs Pancreatic Cancer Cell Migration, Invasion and E-selectin-Dependent Adhesion

Aberrant sialylation is frequently found in pancreatic ductal adenocarcinoma (PDA). α2,3-Sialyltransferases (α2,3-STs) ST3GAL3 and ST3GAL4 are overexpressed in PDA tissues and are responsible for increased biosynthesis of sialyl-Lewis (sLe) antigens, which play an important role in metastasis. This study addresses the effect of α2,3-STs knockdown on the migratory and invasive phenotype of PDA cells, and on E-selectin-dependent adhesion. Characterization of the cell sialome, the α2,3-STs and fucosyltransferases involved in the biosynthesis of sLe antigens, using a panel of human PDA cells showed differences in the levels of sialylated determinants and α2,3-STs expression, reflecting their phenotypic heterogeneity. Knockdown of ST3GAL3 and ST3GAL4 in BxPC-3 and Capan-1 cells, which expressed moderate to high levels of sLe antigens and α2,3-STs, led to a significant reduction in sLe^x and in most cases in sLe^a, with slight increases in the α2,6-sialic acid content. Moreover, ST3GAL3 and ST3GAL4 downregulation resulted in a significant decrease in cell migration and invasion. Binding and rolling to E-selectin, which represent key steps in metastasis, were also markedly impaired in the α2,3-STs knockdown cells. Our results indicate that inhibition of ST3GAL3 and ST3GAL4 may be a novel strategy to block PDA metastasis, which is one of the reasons for its dismal prognosis.

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.

The Diverse Contributions of Fucose Linkages in Cancer

Fucosylation is a post-translational modification of glycans, proteins, and lipids that is responsible for many biological processes. Fucose conjugation via α(1,2), α(1,3), α(1,4), α(1,6), and O'- linkages to glycans, and variations in fucosylation linkages, has important implications for cancer biology. This review focuses on the roles that fucosylation plays in cancer, specifically through modulation of cell surface proteins and signaling pathways. How L-fucose and serum fucosylation patterns might be used for future clinical diagnostic, prognostic, and therapeutic approaches will be discussed.

New observations on the utility of CA19-9 as a biomarker in Lewis negative patients with pancreatic cancer

BACKGROUND

Carbohydrate antigen 19-9 (CA19-9) is the best-validated biomarker for pancreatic cancer. The National Comprehensive Cancer Network (NCCN) guideline asserts that "CA19-9 will be undetectable in Lewis antigen-negative individuals". However, reports of CA19-9 secretion and its significance in Lewis (-) patients with pancreatic cancer have been inconsistent. This study was to examine serum CA19-9 levels in patients with pancreatic cancer according to Lewis status.

METHODS

Patients with pancreatic cancer (1482 cases) were retrieved from a prospectively maintained database. Patients with benign pancreatic disease (210 cases) and normal subjects (315 cases) were used as controls. Lewis genotypes were examined by fucosyltransferase 3 (FUT3) sequencing.

RESULTS

In patients with pancreatic cancer, 8.4% of subjects were Lewis (-), but only 41.9% of Lewis (-) subjects had CA19-9 values ≤ 2 U/mL. CA19-9 was even elevated (>37 U/mL) in 27.4% of Lewis (-) patients. The area under the receiver operating characteristic (ROC) curve for CA19-9 as a diagnostic biomarker was 0.842 in Lewis (-) patients with pancreatic cancer, which is closing to that of CA19-9 applied in all of patients with pancreatic cancer (0.898). Lewis (-) status was an independent prognostic factor for shorter survival in a multivariable analysis (hazard ratio (HR), 1.30, 95% confidence interval (CI), 1.03-1.64; P = 0.028).

CONCLUSIONS

Not all Lewis (-) patients with pancreatic cancer are non-secretors of CA19-9. Contrary to general understanding, CA19-9 can retain its utility as a biomarker in these patients in spite of Lewis (-) genotype.

Knockdown of FUT3 disrupts the proliferation, migration, tumorigenesis and TGF-β induced EMT in pancreatic cancer cells

Fucosyltransferases (FUTs) are critical for glycoproteins and glycolipid chains and serve an important role in the adhesive interaction between selectins and their ligands, which contribute to tumor cell spread and metastasis. While multiple cancer cell lines heavily express FUT3, the present study investigated the expression level of FUT3 in different human pancreatic cancer cell lines. Forced expression and knockdown of FUT3 in different pancreatic cancer cell line demonstrated that FUT3 is important in cell proliferation. Using wound healing and transwell assays, it was observed that the migratory ability was decreased in FUT3 downregulated Capan-1 cell line, compared with the normal Capan-1 cell line. Furthermore, it was demonstrated that the knockdown of FUT3 impaired the adhesion of Capan-1 with E-selectin and inhibited transforming growth factor (TGF)-β-induced epithelial-mesenchymal transition. These data suggest that the knockdown of FUT3 inhibits the tumorigenesis in vivo and FUT3 may be a promising target aiming at reducing the metastatic virulence of pancreatic cancer cells.

Targeting Notch-1 positive acute leukemia cells by novel fucose-bound liposomes carrying daunorubicin

Complete remission by induction therapy in acute myelogenous leukemia (AML) can be achieved due to improvements in supportive and optimized therapy. However, more than 20% of patients will still need to undergo salvage therapy, and most will have a poor prognosis. Determining the specificity of drugs to leukemia cells is important since this will maximize the dose of chemotherapeutic agents that can be administered to AML patients. In turn, this would be expected to lead to reduced drug toxicity and its increased efficacy. We targeted Notch-1 positive AML cells utilizing fucose-bound liposomes, since activation of Notch-1 is required for O-fucosylation. Herein, we report that intravenously injected, L-fucose-bound liposomes containing daunorubicin can be successfully delivered to AML cells that express fucosylated antigens. This resulted in efficient tumor growth inhibition in tumor-bearing mice and decreased proliferation of AML patient-derived leukemia cells. Thus, biological targeting by fucose-bound liposomes that takes advantage of the intrinsic characteristics of AML cells could be a promising new strategy for Notch-1 positive-AML treatment.

Patients with normal-range CA19-9 levels represent a distinct subgroup of pancreatic cancer patients

Pancreatic cancer remains a lethal disease that responds poorly to multiple types of treatment. Therefore, the identification of distinct subgroups that exhibit unique therapeutic responses is an urgent requirement. In the present multicenter study (1,912 cases), the differences between the therapeutic responses and clinical characteristics of two subgroups of pancreatic cancer, carbohydrate antigen 19-9 (CA19-9)-normal (baseline serum level, ≤37 U/ml) and CA19-9-elevated (baseline serum level, >37 U/ml), were analyzed. CA19-9-normal expression was identified to be an independent prognostic factor for patients with stage I-II [hazard ratio (HR)=0.77; P=0.037] and stage III-IV (HR=0.68; P<0.001) pancreatic cancer. The 5-year survival rate of the stage III-IV CA19-9-normal subgroup was increased compared with the stage I-II CA19-9-elevated subgroup (15.4 vs. 13.8%). In the stage I-II CA19-9-normal and CA19-9-elevated subgroups, gemcitabine-based chemotherapy was a significant positive prognostic factor for survival (CA19-9-normal, HR=0.54, P=0.013; CA19-9-elevated, HR=0.55, P<0.001). However, among stage III-IV patients, the CA19-9-normal subgroup exhibited a poor response to gemcitabine-based chemotherapy (HR=0.77; P=0.165), while the CA19-9-elevated subgroup exhibited a favorable response, resulting in a lower rate of mortality (HR=0.70; P<0.001) compared with no chemotherapy. It was concluded that CA19-9-normal pancreatic cancer is a less aggressive subgroup; however, advanced CA19-9-normal pancreatic cancer exhibits a poorer response to gemcitabine-based chemotherapy.

Relationship Between Increased Fucosylation and Metastatic Potential in Colorectal Cancer

BACKGROUND

Fucose is utilized for the modification of different molecules involved in blood group determination, immunological reactions, and signal transduction pathways. We have recently reported that enhanced activity of the fucosyltransferase 3 and/or 6 promoted TGF-ß-mediated epithelial mesenchymal transition and was associated with increased metastatic potential of colorectal cancer (CRC), suggesting that fucose is required by CRC cells. With this in mind, we examined requirement of L-fucose in CRC cells and developed fucose-bound nanoparticles as vehicles for delivery of anticancer drugs specific to CRC.

METHODS

In this study, we first examined the expression of fucosylated proteins in 50 cases of CRC by immunochistochemical staining with biotinylated Aleuria aurantia lectin (AAL). Then we carried out an L-fucose uptake assay using three CRC cell lines. Finally, we developed fucose-bound nanoparticles as vehicles for the delivery of an anticancer drug, SN38, and examined tumor growth inhibition in mouse xenograft model (n = 6 mice per group). All statistical tests were two-sided.

RESULTS

We found a statistically significant relationship between vascular invasion, clinical stage, and intensity score of AAL staining (P≤ .02). L-fucose uptake assay revealed that L-fucose incorporation, as well as fucosylated protein release, was high in cells rich in fucosylated proteins. L-fucose-bound liposomes effectively delivered Cy5.5 into CRC cells. The excess of L-fucose decreased the efficiency of Cy5.5 uptake through L-fucose-bound liposomes, suggesting an L-fucose receptor dependency. Intravenously injected, L-fucose-bound liposomes carrying SN38 were successfully delivered to CRC cells, mediating efficient tumor growth inhibition (relative tumor growth ratio: no treatment group [NT], 8.29 ± 3.09; SN38-treated group [SN38], 3.53 ± 1.47; liposome-carrying, SN38-treated group [F0], 3.1 ± 1.39; L-fucose-bound, liposome-carrying, SN38-treated group [F50], 0.94 ± 0.89; F50 vs NT,P= .003; F50 vs SN38,P= .02, F50 vs F0,P= .04), as well as prolonging survival of mouse xenograft models (log-rank test,P< .001).

CONCLUSIONS

Thus, fucose-bound liposomes carrying anticancer drugs provide a new strategy for the treatment of CRC patients.

Adhesion molecules in peritoneal dissemination: function, prognostic relevance and therapeutic options

Peritoneal dissemination is diagnosed in 10–25 % of colorectal cancer patients. Selected patients are treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. For these patients, earlier diagnosis, optimised selection criteria and a personalised approach are warranted. Biomarkers could play a crucial role here. However, little is known about possible candidates. Considering tumour cell adhesion as a key step in peritoneal dissemination, we aim to provide an overview of the functional importance of adhesion molecules in peritoneal dissemination and discuss the prognostic, diagnostic and therapeutic options of these candidate biomarkers. A systematic literature search was conducted according to the PRISMA guidelines. In 132 in vitro, ex vivo and in vivo studies published between 1995 and 2013, we identified twelve possibly relevant adhesion molecules in various cancers that disseminate peritoneally. The most studied molecules in tumour cell adhesion are integrin α2β1, CD44 s and MUC16. Furthermore, L1CAM, EpCAM, MUC1, sLe^x and Le^x, chemokine receptors, Betaig-H3 and uPAR might be of clinical importance. ICAM1 was found to be less relevant in tumour cell adhesion in the context of peritoneal metastases. Based on currently available data, sLe^a and MUC16 are the most promising prognostic biomarkers for colorectal peritoneal metastases that may help improve patient selection. Different adhesion molecules appear expressed in haematogenous and transcoelomic spread, indicating two different attachment processes. However, our extensive assessment of available literature reveals that knowledge on metastasis-specific genes and their possible candidates is far from complete.

Fut3 role in breast invasive ductal carcinoma: Investigating its gene promoter and protein expression

Fucosylated glycans synthesized by α1,3/4-fucosyltransferase (FUT3) enzyme play an important role in breast cancer prognosis and metastasis, being involved in the binding of circulating tumor cells to the endothelium and being related to tumor stage, metastatic potential and chemoresistance. Despite the pro-tumor action of this enzyme, studies have demonstrated its role in natural killer-induced cytotoxicity through the recognition of sialyl Lewis X by C-type lectin receptors and through extrinsic apoptosis pathway triggered by Apo2L-TRAIL. This study aimed to investigate the expression pattern of FUT3 in invasive breast carcinoma (IDC) from patients of Pernambuco state, Northeast of Brazil, and genotype FUT3 promoter region to identify possible SNPs that could be associated with variations in FUT3 expression. Immunohistochemistry assay was used to access the FUT3 expression in normal (n=11) and tumor tissues (n=85). DNA sequencing was performed to genotype the FUT3 promoter region in patients with IDC (n=109) and healthy controls (n=110). Our results demonstrated that the absence of FUT3 enzyme is related to breast's IDC. The non-expression of FUT3 was more frequent in larger lesions and also in HER2 negative IDC tumors. Genomic analysis showed that two variations localized in FUT3 promoter region are possibly associated with IDC. Our results suggest that minor allele T of SNP rs73920070 (-6933 C>T) confers protection whereas minor allele T of SNP rs2306969 (-6951 C>T) triggers to susceptibility to IDC in the population of Pernambuco state, Northeast of Brazil.

CA-S27: a novel Lewis a associated carbohydrate epitope is diagnostic and prognostic for cholangiocarcinoma

Early and specific diagnosis is critical for treatment of cholangiocarcinoma (CCA). In this study, a carbohydrate antigen-S27 (CA-S27) monoclonal antibody (mAb) was established using pooled CCA tissue-extract as immunogen. The epitope recognized by CA-S27-mAb was a new Lewis-a (Le(a)) associated modification of MUC5AC mucin. A Soybean agglutinin/CA-S27-mAb sandwich ELISA to determine CA-S27 in serum was successfully developed. High level of CA-S27 was detected in serum of CCA patients and could differentiate CCA patients from those of gastro-intestinal cancers, hepatomas, benign hepatobiliary diseases and healthy subjects with high sensitivity (87.5%) and high negative predictive value (90.4%). The level of serum CA-S27 was dramatically reduced after tumor removal, indicating tumor origin of CA-S27. Patients with high serum CA-S27 had significantly shorter survivals than those with low serum CA-S27 regardless of serum MUC5AC levels. Fucosyltransferase-III (FUT3) was shown to be a regulator of CA-S27 expression. Suppression of CA-S27 expression with siRNA-FUT3 or neutralization with CA-S27 mAb significantly reduced growth, adhesion, invasion and migration potentials of CCA cells in vitro. In summary, we demonstrate that serum CA-S27, a novel carbohydrate antigen, has potential as diagnostic and prognostic markers for CCA patients. CA-S27 involves in promoting cell growth, adhesion, migration and invasion of CCA cells.

Sialofucosylated podocalyxin is a functional E- and L-selectin ligand expressed by metastatic pancreatic cancer cells

Selectin-mediated interactions in the vasculature promote metastatic spread by facilitating circulating tumor cell binding to selectin-expressing host cells. Therefore, identifying the selectin ligand(s) on tumor cells is critical to the prevention of blood-borne metastasis. A current challenge is to distinguish between structures expressed by circulating tumor cells that can bind selectins in vitro from the functional ligands whose depletion suppresses selectin-dependent binding under flow in vivo. Interestingly, podocalyxin (PODXL), which can bind E- and L-selectin, is upregulated in a number of cancers, including those of the breast, colon, and pancreas. In this work, we show that metastatic pancreatic cancer cells overexpress PODXL compared with nonmalignant pancreatic epithelial cells. We further demonstrate via tissue microarray that 69% of pancreatic ductal adenocarcinomas stain positive for PODXL. In cases of focal expression, positive staining is restricted to the invasive front of primary tumors. By combining immunoblot, immunodepletion, short-hairpin RNA-mediated gene silencing, and flow-based adhesion assays, we evaluated the functional role of sialofucosylated PODXL in selectin-mediated adhesion under flow. Our data indicate that sialofucosylated PODXL is a functional E- and L-selectin ligand expressed by metastatic pancreatic cancer cells, as specific depletion of this molecule from the cell surface significantly interferes with selectin-dependent interactions. Cumulatively, these data support a correlation between sialofucosylated PODXL expression and enhanced binding to selectins by metastatic pancreatic cancer cells and offer additional perspective on the upregulation of PODXL in aggressive cancers.

Targeting anticancer drug delivery to pancreatic cancer cells using a fucose-bound nanoparticle approach

Owing to its aggressiveness and the lack of effective therapies, pancreatic ductal adenocarcinoma has a dismal prognosis. New strategies to improve treatment and survival are therefore urgently required. Numerous fucosylated antigens in sera serve as tumor markers for cancer detection and evaluation of treatment efficacy. Increased expression of fucosyltransferases has also been reported for pancreatic cancer. These enzymes accelerate malignant transformation through fucosylation of sialylated precursors, suggesting a crucial requirement for fucose by pancreatic cancer cells. With this in mind, we developed fucose-bound nanoparticles as vehicles for delivery of anticancer drugs specifically to cancer cells. L-fucose-bound liposomes containing Cy5.5 or Cisplatin were effectively delivered into CA19-9 expressing pancreatic cancer cells. Excess L-fucose decreased the efficiency of Cy5.5 introduction by L-fucose-bound liposomes, suggesting L-fucose-receptor-mediated delivery. Intravenously injected L-fucose-bound liposomes carrying Cisplatin were successfully delivered to pancreatic cancer cells, mediating efficient tumor growth inhibition as well as prolonging survival in mouse xenograft models. This modality represents a new strategy for pancreatic cancer cell-targeting therapy.

Down-regulation of FUT3 and FUT5 by shRNA alters Lewis antigens expression and reduces the adhesion capacities of gastric cancer cells

BACKGROUND

Lewis antigens are fucosylated glycoconjugates involved in the development of several pathologies. The adhesion of sialyl-Lewis antigens to E-selectin is a key step in the development of metastasis and the glycosidic component of CD44 plays a key role in the binding to hyaluronic acid, a component of the extracellular matrix associated to tumor development and invasion. Fucosyltransferases are enzymes that add fucose to precursor glycan structures: FUT3 and FUT5 catalyze the addition of fucose to the α1-3,4 position and are detected in epithelial cells. In this study, we have analyzed the effects of silencing FUT3, FUT5 or FUT3/FUT5, in two gastric cancer cell lines, in the expression of Lewis antigens and in the adhesive and migratory capacities of the cells.

METHODS

FUT3, FUT5 and FUT3/FUT5 were down-regulated using lentiviral delivery of shRNAs in MKN45 and GP220 gastric cancer cells.

RESULTS

In the infected cells, decreased levels of FUT3 and FUT5 mRNA detected by quantitative RT-PCR; and lower levels of sialyl-Lewis antigens, evaluated by flow cytometry, were observed. The adhesion to endothelial cells trough the binding to E-selectin, and the binding to hyaluronic acid were reduced in the shFUT3, shFUT5 and shFUT3/FUT5, whereas the levels of CD44, analyzed by western blot, did not change.

GENERAL SIGNIFICANCE

The down-regulation of FUT3, FUT5 and FUT3/FUT5 reduces the expression of sialyl-Lewis antigens and the adhesion and binding capacities of gastric cancer cells; and allows to identify the specific α1-3,4 fucosyltransferases implicated in the Lewis antigens synthesis in this cellular model.

Knockdown of fucosyltransferase III disrupts the adhesion of circulating cancer cells to E-selectin without affecting hematopoietic cell adhesion

Adhesive interactions between selectins and their ligands play an essential role during cancer extravasation. Fucosylation of these proteins by fucosyltransferases, or FUTs, is critical for their functions. Using quantitative RT-PCR, we demonstrated that FUT4 and FUT7 are the predominant FUTs expressed in hematopoietic cell line, while FUT3 is heavily expressed by multiple cancer cell lines including the prostate cancer cell line MDA PCa2b. Knockdown of FUT3 expression in MDA PCa2b cells by small interference RNA (siRNA) significantly reduced FUT3 expression. Cell-surface sialyl Lewis antigens were largely abolished. Cell adhesion and cell rolling on the blood vessel wall were simulated by perfusing cancer cells through microtubes coated with recombinant human E-selectin. At physiological levels of wall shear stress, the number of flowing cancer cells recruited to the microtube surface was dramatically reduced by FUT3 knockdown. Higher rolling velocity was also observed, which is consistent with reduced E-selectin binding activity. Interestingly, FUT3 siRNA treatment also significantly reduced the cell growth rate. Combined with the novel siRNA delivery platform recently developed in our laboratory, FUT3 siRNA could be a promising conjunctive therapy aiming at reducing the metastatic virulence of circulating epithelial cancer cells.

Alpha 1,3 fucosyltransferases are master regulators of prostate cancer cell trafficking

How cancer cells bind to vascular surfaces and extravasate into target organs is an underappreciated, yet essential step in metastasis. We postulate that the metastatic process involves discrete adhesive interactions between circulating cancer cells and microvascular endothelial cells. Sialyl Lewis X (sLe(X)) on prostate cancer (PCa) cells is thought to promote metastasis by mediating PCa cell binding to microvascular endothelial (E)-selectin. Yet, regulation of sLe(X) and related E-selectin ligand expression in PCa cells is a poorly understood factor in PCa metastasis. Here, we describe a glycobiological mechanism regulating E-selectin-mediated adhesion and metastatic potential of PCa cells. We demonstrate that alpha1,3 fucosyltransferases (FT) 3, 6, and 7 are markedly elevated in bone- and liver-metastatic PCa and dictate synthesis of sLe(X) and E-selectin ligands on metastatic PCa cells. Upregulated FT3, FT6, or FT7 expression induced robust PCa PC-3 cell adhesion to bone marrow (BM) endothelium and to inflamed postcapillary venules in an E-selectin-dependent manner. Membrane proteins, CD44, carcinoembryonic antigen (CEA), podocalyxin-like protein (PCLP), and melanoma cell adhesion molecule (MCAM) were major scaffolds presenting E-selectin-binding determinants on FT-upregulated PC-3 cells. Furthermore, elevated FT7 expression promoted PC-3 cell trafficking to and retention in BM through an E-selectin dependent event. These results indicate that alpha1,3 FTs could enhance metastatic efficiency of PCa by triggering an E-selectin-dependent trafficking mechanism.

Evaluation of the serum N-linked glycome for the diagnosis of cancer and chronic inflammation

The identification of serum biomarkers has lead to improvements in the detection and diagnosis of cancer, and combinations of these biomarkers have increased further their sensitivity and specificity. Glycosylation is the most common PTM of secreted proteins and the identification of novel serum glyco-biomarkers has become a topic of increasing interest because the glycan processing pathways are frequently disturbed in cancer cells. A future goal is to combine current biomarkers with glyco-biomarkers to yield further improvements. Well characterised N-glycosylation changes in the serum glycome of cancer patients include changes in the levels of tri- and tetra-antennary glycan structures, sialyl Lewis X epitopes and agalactosylated bi-antennary glycans. Several of these glycosylated markers have been linked to chronic inflammatory diseases, promoting questions about the links between inflammation and cancer. In this review, the glycoproteins which display these glycan epitopes, the glycosyl transferases which can generate them, their potential functions and their use as biomarkers are evaluated.

Analysis of glycosyltransferase expression in metastatic prostate cancer cells capable of rolling activity on microvascular endothelial (E)-selectin

Prostate cancer (PCa) cell tethering and rolling on microvascular endothelium has been proposed to promote the extravasation of PCa cells. We have shown that these adhesive events are mediated through binding interactions between endothelial (E)-selectin and Lewis carbohydrates on PCa cells. Prior data indicate that E-selectin-mediated rolling of bone-metastatic PCa MDA PCa 2b (MDA) cells is dependent on sialyl Lewis X (sLe(X))-bearing glycoproteins. To explore the molecular basis of sLe(X) synthesis and E-selectin ligand (ESL) activity on PCa cells, we compared and contrasted the expression level of glycosyltransferases, characteristically involved in sLe(X) and ESL synthesis, in ESL(+) MDA cells among other ESL(-) metastatic PCa cell lines. We also created and examined ESL(hi) and ESL(lo) variants of MDA cells to provide a direct comparison of the glycosyltransferase expression level. We found that normal prostate tissue and all metastatic PCa cell lines expressed glycosyltransferases required for sialo-lactosamine synthesis, including N-acetylglucosaminyl-, galactosyl-, and sialyltransferases. However, compared with expression in normal prostate tissue, ESL(+) MDA cells expressed a 31- and 10-fold higher level of alpha1,3 fucosyltransferases (FT) 3 and 6, respectively. Moreover, FT3 and FT6 were expressed at 2- to 354-fold lower levels in ESL(-) PCa cell lines. Consistent with these findings, ESL(hi) MDA cells expressed a 131- and 51-fold higher level of FT3 and FT6, respectively, compared with expression in ESL(lo) MDA cells. We also noted that alpha1,3 FT7 was expressed at a 5-fold greater level in ESL(hi) MDA cells. Furthermore, ESL(lo) MDA cells did not display sLe(X) on glycoproteins capable of bearing sLe(X), notably P-selectin glycoprotein ligand-1. These results implicate the importance of alpha1,3 FT3, FT6, and/or FT7 in sLe(X) and ESL synthesis on metastatic PCa cells.

Role of sialyltransferases involved in the biosynthesis of Lewis antigens in human pancreatic tumour cells

The sialylated carbohydrate antigens, sialyl-Lewisx and sialyl-Lewisa, are expressed in pancreatic tumour cells and are related to their metastatic potential. While the action of the fucosyltransferases involved in the synthesis of these antigens has already been investigated, no studies have been carried out on the activity and expression of the alpha 2,3-sialyltransferases in pancreatic tumour cells. We describe the sialyltransferase (ST) activity, mRNA expression, and analysis of the cell carbohydrate structures in four human pancreatic adenocarcinoma cell lines of a wide range of neoplastic differentiation stages and in normal human pancreatic tissues. Total ST activity measured on asialofetuin, employing a CMP fluorescent sialic acid, varied among the pancreatic cell lines and could be correlated to the expression of their cell surface antigens. However, in some of the pancreatic cell lines, no relationship could be established with their ST3Gal III and IV mRNA expression. Human pancreatic tissues also showed ST expression and activity. However, it presented a much higher expression of neutral fucosylated structures than sialylated structures. In conclusion, ST activity levels in pancreatic cells could be correlated to their expression of sialylated epitopes, which indicates their involvement in the formation of the sialyl-Lewis antigens, in addition to fucosyltransferase activities.

Decrease of human pancreatic cancer cell tumorigenicity by alpha1,3galactosyltransferase gene transfer

The enzyme alpha1,3galactosyltransferase synthesizes the alphaGal epitope, a carbohydrate structure (Galalpha1,3Galbeta1,4GlcNAc-R), on glycoconjugates in lower mammals. The enzyme is absent in humans but large amounts of natural antibodies that recognize alphaGal epitopes are present in human serum. It is likely that these antibodies contribute to the host defense and participate in the hyperacute rejection of xenograft. Previous studies indicated that the glycosyltransferase gene transfer into tumoral cells can modify the structure of glycoconjugates at the cell surface and, as a consequence, modulates the metastatic and tumorigenic behaviors of these cells. The aim of our study was to determine whether the expression of alphaGal epitope can modify the tumorigenicity of human pancreatic cancer cells. The expression of alphaGal epitopes in the human pancreatic cancer cell lines BxPC-3 and Panc-1 was obtained by selecting stable cell clones transfected with murine alpha1,3galactosyltransferase gene. The expression of the enzyme activity in BxPC-3 and Panc-1 cells resulted in the formation at the cell surface of alphaGal epitopes that are recognized by human anti-alphaGal antibodies. alphaGal epitope expression at the surface of pancreatic cancer cells was associated with the fixation of complement 1q to human anti-alphaGal antibodies. The alphaGal epitope expression also resulted in a delay in the tumoral development of BxPC-3 and Panc-1 cells in vivo after xenograft transplantation of nude mice. In addition to the impairment of the metastatic potential of murine tumor cell lines and the activation of immune response, our study provides evidence that the cell surface expression of alphaGal epitopes also modulates the tumorigenic behavior of human pancreatic cancer cells.