Lectin BS-I inhibits cell migration and invasion via AKT/GSK-3β/β-catenin pathway in hepatocellular carcinoma

Anticancer Activity of Mannose-Specific Lectin, BPL2, from Marine Green Alga Bryopsis plumosa

Lectin is a carbohydrate-binding protein that recognizes specific cells by binding to cell-surface polysaccharides. Tumor cells generally show various glycosylation patterns, making them distinguishable from non-cancerous cells. Consequently, lectin has been suggested as a good anticancer agent. Herein, the anticancer activity of Bryopsis plumosa lectins (BPL1, BPL2, and BPL3) was screened and tested against lung cancer cell lines (A549, H460, and H1299). BPL2 showed high anticancer activity compared to BPL1 and BPL3. Cell viability was dependent on BPL2 concentration and incubation time. The IC₅₀ value for lung cancer cells was 50 μg/mL after 24 h of incubation in BPL2 containing medium; however, BPL2 (50 μg/mL) showed weak toxicity in non-cancerous cells (MRC5). BPL2 affected cancer cell growth while non-cancerous cells were less affected. Further, BPL2 (20 μg/mL) inhibited cancer cell invasion and migration (rates were ˂20%). BPL2 induced the downregulation of epithelial-to-mesenchymal transition-related genes (Zeb1, vimentin, and Twist). Co-treatment with BPL2 and gefitinib (10 μg/mL and 10 μM, respectively) showed a synergistic effect compared with monotherapy. BPL2 or gefitinib monotherapy resulted in approximately 90% and 70% cell viability, respectively, with concomitant treatment showing 40% cell viability. Overall, BPL2 can be considered a good candidate for development into an anticancer agent.

Lens culinaris agglutinin inhibits human hepatoma cell migration via mannose and fucose-mediated ERK1/2 and JNK1/2/3 signalling pathway

BACKGROUND

Hepatocellular carcinoma (HCC) is the main types of primary liver cancer, which shows some abnormal glycosylation, such as the increase of fucose. Lens culinaris agglutinin (LCA), a natural plant lectin that can bind to mannose and fucose, has been reported to be antiproliferative to may tumors. However, the effect of LCA on the vitality and migration ability of human hepatoma cells is not demonstrated. Therefore, the aim of this study is to investigate the effects of LCA on vitality and migration in human hepatoma cells and its potential mechanisms.

METHODS AND RESULTS

LCA had no significant effect on viability of human hepatoma cells (HCCLM3, MHCC97L and HepG2) and hepatocytes (L02) by CCK-8 kit, but it could inhibit human hepatoma cells migration significantly without affecting hepatocytes by Transwell method. Sugar inhibition assay was used to verify the possible binding site between LCA and human hepatoma cells. The result showed that Mannose- and fucose- related sites were associated with LCA inhibiting human hepatoma cells migration. Moreover, LCA could affect HCCLM3 migration by activating ERK1/2 and JNK1/2/3 signalling pathways. LCA did not affect MMP-2 and MMP-9 of HCCLM3 through gelatinase zymography. However, the results of immunofluorescence standing showed that LCA could reduce the F-actin formation in HCCLM3 via ERK1/2 and JNK1/2/3 signalling pathways.

CONCLUSIONS

LCA might inhibit human hepatoma cell migration by reducing the F-actin formation via the mannose and fucose-mediated ERK1/2 and JNK1/2/3 signalling pathway. This result will deepen people's understanding on plant lectin as a drug in tumor glycobiology.

Caveolin-1 knockout mice have altered serum N-glycan profile and sialyltransferase tissue expression

Caveolin-1 (Cav-1) is a constitutive protein within caveolar membranes. Previous studies from our group and others indicated that Cav-1 could mediate N-glycosylation, α2,6-sialylation, and fucosylation in mouse hepatocarcinoma cells in vitro. However, little is known about the effect of Cav-1 expression on glycosylation modifications in vivo. In this study, the N-glycan profiles in serum from Cav-1^-/- mice were investigated by lectin microarray and mass spectrometric analysis approaches. The results showed that levels of multi-antennary branched, α2,6-sialylated, and galactosylated N-glycans increased, while high-mannose typed and fucosylated N-glycans decreased in the serum of Cav-1^-/- mice, compared with that of wild-type mice. Furthermore, the real-time quantitative PCR analysis indicated that α2,6-sialyltransferase gene expression decreased significantly in Cav-1^-/- mouse organ tissues, but α2,3- and α2,8-sialyltransferase did not. Of them, both mRNA and protein expression levels of the β-galactoside α2,6-sialyltransferase 1 (ST6Gal-I) had dramatically reduced in Cav-1^-/- mice organ tissues, which was consistent with the α2,6-sialyl Gal/GalNAc level reduced significantly in tissues instead of serum from Cav-1^-/- mice. These results provide for the first time the N-glycans profile of Cav-1^-/- mice serum, which will facilitate understanding the function of Cav-1 from the perspective of glycosylation.

Wnt/β-Catenin Signaling as a Driver of Hepatocellular Carcinoma Progression: An Emphasis on Molecular Pathways

Liver cancers cause a high rate of death worldwide and hepatocellular carcinoma (HCC) is considered as the most common primary liver cancer. HCC remains a challenging disease to treat. Wnt/β-catenin signaling pathway is considered a tumor-promoting factor in various cancers; hence, the present review focused on the role of Wnt signaling in HCC, and its association with progression and therapy response based on pre-clinical and clinical evidence. The nuclear translocation of β-catenin enhances expression level of genes such as c-Myc and MMPs in increasing cancer progression. The mutation of CTNNB1 gene encoding β-catenin and its overexpression can lead to HCC progression. β-catenin signaling enhances cancer stem cell features of HCC and promotes their growth rate. Furthermore, β-catenin prevents apoptosis in HCC cells and increases their migration via triggering EMT and upregulating MMP levels. It is suggested that β-catenin signaling participates in mediating drug resistance and immuno-resistance in HCC. Upstream mediators including ncRNAs can regulate β-catenin signaling in HCC. Anti-cancer agents inhibit β-catenin signaling and mediate its proteasomal degradation in HCC therapy. Furthermore, clinical studies have revealed the role of β-catenin and its gene mutation (CTNBB1) in HCC progression. Based on these subjects, future experiments can focus on developing novel therapeutics targeting Wnt/β-catenin signaling in HCC therapy.

Identification of LCA-binding Glycans as a Novel Biomarker for Esophageal Cancer Metastasis using a Lectin Array-based Strategy

Esophageal cancer (EC) is a unique and heterogeneous disease diagnosed mostly at advanced stages. Altered glycans presented on cell surfaces are involved in the occurrence and development of malignancy. However, the effects of glycans on EC progression are largely unexplored. Here, a lectin array was utilized to detect the glycan profiling of the normal esophageal mucosal epithelial cell line and two EC cell lines. The binding of Lens culinaris lectin (LCA) to EC cells was found to be stronger than that of the normal cells. Lectin immunohistochemical staining revealed that LCA-binding glycans were markedly elevated in EC tissues compared to adjacent non-cancerous tissues. LCA staining was significantly associated with lymph node metastasis, depth of invasion, TNM stage and poor overall survival of EC patients. Added LCA to block LCA recognized glycans could inhibit the migration and invasion of EC cells. Further analysis revealed that blocking the biosynthesis of LCA-binding glycans by tunicamycin attenuated cellular migratory and invasive abilities. Additionally, a membrane glycoprotein CD147 was recognized as a binder of LCA. There was a positive correlation between LCA-binding glycans and CD147 expression in clinical samples. Interestingly, CD147 inhibition also reduced cell migration and invasion. These findings indicated that LCA-binding glycans may function as a novel indicator to predict metastasis for patients with EC.

Lectin microarrays for glycoproteomics: an overview of their use and potential

Introduction: Glycoproteomics is an important subdiscipline of proteomics, focusing on the role of protein glycosylation in various biological processes. Protein glycosylation is the enzymatic addition of sugars or oligosaccharides to proteins. Altered glycosylation often occurs in the early stages of disease development, for example, certain tumor-associated glycans have been shown to be expressed in precursor lesions of different types of cancer, making them powerful early diagnostic markers. Lectin microarrays have become a powerful tool for both the study of glycosylation and the diagnosis of various diseases including cancer.Areas covered: This review will discuss the most useful features of lectin microarrays, such as their technological advances, their capability for parallel/high-throughput analysis for the important glycopatterns of glycoprotein, and an overview of their use for glycosylation analysis of various complex protein samples, as well as their diagnostic potential in various diseases.Expert opinion: Lectin microarrays have proved to be useful in studying multiple lectin-glycan interactions in a single experiment and, with the advances made in the field, hold a promise of enabling glycopatterns of diseases in a fast and efficient manner. Lectin microarrays will become increasingly powerful early diagnostic tool for a variety of conditions.

High expression of PDE4D correlates with poor prognosis and clinical progression in pancreaticductal adenocarcinoma

BACKGROUND

Phosphodiesterase 4D (PDE4D) has recently been reported as an oncogene in various types of human cancers. However, the expression and significance of PDE4D in pancreatic ductal adenocarcinoma (PDAC) have not been elucidated. Methods: Immunohistochemistry (IHC) was used to examine the expression of PDE4D in 104 clinicopathologically characterized PDAC cases. PDE4D expression in paired tumor tissues and adjacent noncancerous tissues were detected by western blotting and real time qRT-PCR. The correlation of PDE4D expression levels with clinicopathological features and prognosis in patients were analyzed by univariate and multivariate methods. Effect of PDE4D on pancreatic cancer cells was detected by cell migration and invasion assays. Results: We found that PDE4D was significantly up-regulated in PDAC tumor tissues compared to those paired adjacent noncancerous tissues at both protein and mRNA levels. High level of PDE4D was significantly associated with clinical stage (P = 0.004), T classification (P = 0.003), lymph node metastasis (P = 0.022) and liver metastasis (P = 0.038). Patients with higher levels of PDE4D had shorter overall survival time contrast with those with lower PDE4D expression (P = 0.002). Multivariate analysis indicated that PDE4D may be an independent prognostic factor for PDAC. PDE4D depletion significantly suppressed β-catenin and Snail expression as well as the migration and invasion abilities of pancreatic cancer cells. Conclusions: Our study reveals that PDE4D up-regulated in PDAC was closely associated with poor prognosis of PDAC patients and multiple aggressive clinicopathological characteristics. PDE4D could be a useful prognostic biomarker and therapeutic target for PDAC.

Proteolysis is the most fundamental property of malignancy and its inhibition may be used therapeutically (Review)

The mortality rates of cancer patients decreased by ~1.5% per year between 2001 and 2015, although the decrease depends on patient sex, ethnic group and type of malignancy. Cancer remains a significant global health problem, requiring a search for novel treatments. The most common property of malignant tumors is their capacity to invade adjacent tissue and to metastasize, and this cancer aggressiveness is contingent on overexpression of proteolytic enzymes. The components of the plasminogen activation system (PAS) and the metal-loproteinase family [mainly matrix metalloproteinases (MMPs)] are overexpressed in malignant tumors, driving the local invasion, metastasis and angiogenesis. This is the case for numerous types of cancer, such as breast, colon, prostate and oral carcinoma, among others. Present chemotherapeutics agents typically attack all dividing cells; however, for future therapeutic agents to be clinically successful, they need to be highly selective for a specific protein(s) and act on the cancerous tissues without adverse systemic effects. Inhibition of proteolysis in cancerous tissue has the ability to attenuate tumor invasion, angiogenesis and migration. For that purpose, inhibiting both PAS and MMPs may be another approach, since the two groups of enzymes are overexpressed in cancer. In the present review, the roles and new findings on PAS and MMP families in cancer formation, growth and possible treatments are discussed.