The role of glycosyltransferase enzyme GCNT3 in colon and ovarian cancer prognosis and chemoresistance

Bulk and single-cell RNA sequencing analyses coupled with multiple machine learning to develop a glycosyltransferase associated signature in colorectal cancer

BACKGROUND

This study aims to identify key glycosyltransferases (GTs) in colorectal cancer (CRC) and establish a robust prognostic signature derived from GTs.

METHODS

Utilizing the AUCell, UCell, singscore, ssgsea, and AddModuleScore algorithms, along with correlation analysis, we redefined genes related to GTs in CRC at the single-cell RNA level. To improve risk model accuracy, univariate Cox and lasso regression were employed to discover a more clinically subset of GTs in CRC. Subsequently, the efficacy of seven machine learning algorithms for CRC prognosis was assessed, focusing on survival outcomes through nested cross-validation. The model was then validated across four independent external cohorts, exploring variations in the tumor microenvironment (TME), response to immunotherapy, mutational profiles, and pathways of each risk group. Importantly, we identified potential therapeutic agents targeting patients categorized into the high-GARS group.

RESULTS

In our research, we classified CRC patients into distinct subgroups, each exhibiting variations in prognosis, clinical characteristics, pathway enrichments, immune infiltration, and immune checkpoint genes expression. Additionally, we established a Glycosyltransferase-Associated Risk Signature (GARS) based on machine learning. GARS surpasses traditional clinicopathological features in both prognostic power and survival prediction accuracy, and it correlates with higher malignancy levels, providing valuable insights into CRC patients. Furthermore, we explored the association between the risk score and the efficacy of immunotherapy.

CONCLUSION

A prognostic model based on GTs was developed to forecast the response to immunotherapy, offering a novel approach to CRC management.

GCNT3 regulated MUC13 to promote the development of hepatocellular carcinoma through the GSK3β/β-catenin pathway

BACKGROUND

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths worldwide. Extensive research is currently directed at identifying novel targets for its diagnosis and treatment.

AIMS

We investigated the biological functions and clinical significance of mucin-type N-acetylglucosaminyltransferase 3 (GCNT3) in HCC.

METHODS

Variations in the mRNA expression of GCNT3 were examined in normal and HCC tissues. Cell function assays and animal models characterized the effects of GCNT3 on the proliferation, invasion, and migration abilities of HCC cells. Western blot and immunofluorescence analyses were performed to explore further the specific mechanisms whereby GCNT3 affects HCC progression.

RESULTS

There is a strong correlation between GCNT3 overexpression and tumor formation and metastasis in vivo and in vitro. GCNT3 acted as a regulator of the synthesis of mucin-type O-glycans by interacting with mucin 13 (MUC13) to regulate its expression levels, activating the GSK3β/β-catenin signaling pathway. The activation of GSK3β/β-catenin signaling by GCNT3 was mitigated by MUC13 knockdown. In clinical HCC specimens, GCNT3 expression was upregulated in HCC tissues compared to non-tumor tissues. Further, there was a significant correlation between high GCNT3 expression and poor patient survival.

CONCLUSIONS

GCNT3 regulated tumor progression in HCC through the MUC13/GSK3-β/β-catenin signaling pathway.

Phytocompounds and Nanoformulations for Anticancer Therapy: A Review

Cancer is a complex disease that affects millions of people and remains a major public health problem worldwide. Conventional cancer treatments, including surgery, chemotherapy, immunotherapy, and radiotherapy, have limited achievements and multiple drawbacks, among which are healthy tissue damage and multidrug-resistant phenotype onset. Increasing evidence shows that many plants' natural products, as well as their bioactive compounds, have promising anticancer activity and exhibit minimal toxicity compared to conventional anticancer drugs. However, their widespread use in cancer therapy is severely restricted by limitations in terms of their water solubility, absorption, lack of stability, bioavailability, and selective targeting. The use of nanoformulations for plants' natural product transportation and delivery could be helpful in overcoming these limitations, thus enhancing their therapeutic efficacy and providing the basis for improved anticancer treatment strategies. The present review is aimed at providing an update on some phytocompounds (curcumin, resveratrol, quercetin, and cannabinoids, among others) and their main nanoformulations showing antitumor activities, both in vitro and in vivo, against such different human cancer types as breast and colorectal cancer, lymphomas, malignant melanoma, glioblastoma multiforme, and osteosarcoma. The intracellular pathways underlying phytocompound anticancer activity and the main advantages of nanoformulation employment are also examined. Finally, this review critically analyzes the research gaps and limitations causing the limited success of phytocompounds' and nanoformulations' clinical translation.

Results from a real-world study: a novel glycosyltransferase risk score for prognosis, tumor microenvironment phenotypes and immunotherapy in bladder cancer

BACKGROUND

Although immunotherapy shows tremendous potential in the treatment of bladder cancer (BLCA), the overall prognosis and response rates to immunotherapy in BLCA remain suboptimal.

METHODS

We performed an extensive evaluation of glycosyltransferase expression patterns in BLCA patients by analyzing 210 glycosyltransferase-related genes. Subsequently, we established correlations between these glycosyltransferase patterns, prognosis, and tumor microenvironment (TME) phenotypes. To offer personalized patient assessments, we developed a glycosyltransferase risk score that accurately predicts prognosis, TME phenotypes, and molecular subtypes. Importantly, we developed a RNA-seq cohort, named Xiangya cohort, to validate our results.

RESULTS

Two distinct patterns of glycosyltransferase expression were identified, corresponding to inflamed and noninflamed TME phenotypes, and demonstrated the potential to predict prognosis. We developed and validated a comprehensive risk score that accurately predicted individual patient prognosis in the TCGA-BLCA cohort. Additionally, we constructed a nomogram that integrated the risk score with several key clinical factors. Importantly, this risk score was successfully validated in external cohorts, including the Xiangya cohort and GSE48075. Furthermore, we discovered a positive correlation between this risk score and tumor-infiltrating lymphocytes in both the TCGA-BLCA and Xiangya cohorts, suggesting that patients with a higher risk score exhibited an inflamed TME phenotype and were more responsive to immunotherapy. Finally, we observed that the high and low risk score groups were consistent with the luminal and basal subtypes of BLCA, respectively, providing further validation of the risk score's role in the TME in terms of molecular subtypes.

CONCLUSIONS

Glycosyltransferase patterns exhibit distinct TME phenotypes in BLCA. Our comprehensive risk score provides a promising approach for prognostic prediction and assessment of immunotherapy efficacy, offering valuable guidance for precision medicine.

Study on the regulatory mechanism of latent membrane protein 2A on GCNT3 expression in nasopharyngeal carcinoma

O-Glycan synthesis enzyme glucosaminyl (N-acetyl) transferase 3 (GCNT3) is closely related to the occurrence and development of various cancers. However, the regulatory mechanism and function of GCNT3 in nasopharyngeal carcinoma (NPC) are still poorly understood. This study aims to explore the regulatory mechanism of EBV-encoded latent membrane protein 2A (LMP2A) on GCNT3 and the biological role of GCNT3 in NPC. The results show that LMP2A can activate GCNT3 through the mTORC1 pathway, and there is a positive feedback between the mTORC1 and GCNT3. GCNT3 regulates EMT progression by forming a complex with ZEB1 to promote cell migration. GCNT3 can also promote cell proliferation. These findings indicate that targeting the LMP2A-mTORC1-GCNT3 axis may represent a novel therapeutic target in NPC.

GCNT3 Promotes Hepatocellular Carcinoma Progression and EMT by Activating the PI3K/AKT Pathway

Primary liver cancer, specifically hepatocellular carcinoma (HCC), is a major global health concern. GCNT3 has been identified as an oncogene in various human malignancies. This investigation aimed to discover the GCNT3 function in HCC. The present study employed integrated bioinformatics analyses to assess the expression pattern, prognostic implications, and putative function of GCNT3 in HCC. Transwell flow cytometry, CCK-8, and wound healing assays were performed to examine HCC cell growth, cell cycle, apoptosis, invasion, and migration. In addition, the epithelial-mesenchymal transition (EMT) markers and PI3K/AKT mechanism markers were examined via western blot analysis to elucidate the underlying mechanisms. In HCC, GCNT3 was significantly overexpressed, which was connected with enhanced tumor aggressiveness and an unfavorable prognosis of individuals. In vitro experiments demonstrated that elevated levels of GCNT3 promoted cell growth, migration, cell cycle development, and invasion, in addition to EMT, while suppressing apoptosis. Conversely, knockdown of GCNT3 exerted the opposite effects. GCNT3 overexpression increased PI3K/AKT phosphorylation in HCC cells, and LY294002 counteracted the impacts of upregulated GCNT3 on cell cycle, migration, invasion, proliferation, and EMT in HCC. The investigation showed that GCNT3 may enhance HCC progression and EMT by stimulating PI3K/AKT mechanism.

Identification of glycosyltransferase-related genes signature and integrative analyses in patients with ovarian cancer

BACKGROUND

Glycosyltransferases (GT) play a crucial role in glycosylation reactions, and aberrant expression of glycosyltransferase-related genes (GTs) leads to abnormal glycosylation, which is associated with tumor progression. However, the prognostic value of aberrant expression of GTs in ovarian cancer (OC) and the correlation between GTs and tumor microenvironment (TME) remain unknown.

METHODS

TCGA and GSE53963 databases were used to obtain data on OC patient samples. The association of GTs with OC was analyzed. Molecular subtypes were identified by consensus unsupervised clustering, followed by immune infiltration and functional enrichment analyses. Survival analysis was performed using Kaplan-Meier curves and log-rank tests. Least Absolute Shrinkage and Selection Operator (LASSO) and multifactorial cox regression were used to screen for signature genes associated with OC and used to establish prognostic models.

RESULT

OC patients were categorized into 5 GTs clusters using consensus unsupervised cluster analysis. Clusters D and E showed significant differences between survival, signaling pathways and immune infiltration. Then, a risk model was developed based on the 12 signature genes, which provides a more accurate evaluation of the prognosis of OC patients. We categorized patients into high-risk and low-risk groups based on the risk score and found that the survival of patients in the high-risk group was significantly lower than that in the low-risk group. Moreover, the risk score was significantly correlated with tumor microenvironment, immune infiltration, and chemotherapy sensitivity.

CONCLUSION

Overall, we performed a comprehensive analysis of GTs in OC patients and developed a risk model for OC. Our findings will provide a new insight to OC prognosis and treatment.

Protein post-translational modifications: A key factor in colorectal cancer resistance mechanisms

Colorectal cancer (CRC) is one of the leading causes of cancer-related death. Despite advances in treatment, drug resistance remains a critical impediment. Post-translational modifications (PTMs) regulate protein stability, localization, and activity, impacting vital cellular processes. Recent research has highlighted the essential role of PTMs in the development of CRC resistance. This review summarizes recent advancements in understanding PTMs' roles in CRC resistance, focusing on the latest discoveries. We discuss the functional impact of PTMs on signaling pathways and molecules involved in CRC resistance, progress in drug development, and potential therapeutic targets. We also summarize the primary enrichment methods for PTMs. Finally, we discuss current challenges and future directions, including the need for more comprehensive PTM analysis methods and PTM-targeted therapies. This review identifies potential therapeutic interventions for addressing medication resistance in CRC, proposes prospective therapeutic options, and gives an overview of the function of PTMs in CRC resistance.

Talniflumate abrogates mucin immune suppressive barrier improving efficacy of gemcitabine and nab-paclitaxel treatment in pancreatic cancer

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease. This is due to its aggressive course, late diagnosis and its intrinsic drugs resistance. The complexity of the tumor, in terms of cell components and heterogeneity, has led to the approval of few therapies with limited efficacy. The study of the early stages of carcinogenesis provides the opportunity for the identification of actionable pathways that underpin therapeutic resistance.

METHODS

We analyzed 43 Intraductal papillary mucinous neoplasms (IPMN) (12 Low-grade and 31 High-grade) by Spatial Transcriptomics. Mouse and human pancreatic cancer organoids and T cells interaction platforms were established to test the role of mucins expression on T cells activity. Syngeneic mouse model of PDAC was used to explore the impact of mucins downregulation on standard therapy efficacy.

RESULTS

Spatial transcriptomics showed that mucin O-glycosylation pathway is increased in the progression from low-grade to high-grade IPMN. We identified GCNT3, a master regulator of mucins expression, as an actionable target of this pathway by talniflumate. We showed that talniflumate impaired mucins expression increasing T cell activation and recognition using both mouse and human organoid interaction platforms. In vivo experiments showed that talniflumate was able to increase the efficacy of the chemotherapy by boosting immune infiltration.

CONCLUSIONS

Finally, we demonstrated that combination of talniflumate, an anti-inflammatory drug, with chemotherapy effectively improves anti-tumor effect in PDAC.

Exploration of glycosyltransferases mutation status in cervical cancer reveals PARP14 as a potential prognostic marker

This study investigates the potential role of Glycosyltransferases (GTs) in the glycosylation process and their association with malignant tumors. Specifically, the study focuses on PARP14, a member of GTs, and its potential as a target for tumors in the diagnosis and treatment of cervical cancer. To gather data, the study used somatic mutation data, gene expression data and clinical information from TCGA-CESE dataset as well as tissue samples from cervical cancer patients. Further verification was conducted through RT-qPCR and immunohistochemistry staining on cervical cancer tissues to confirm the expression of PARP14. The study utilized Kaplan-Meier for survival analysis of cervical cancer patient and found significant mutational abnormalities in GTs. The high frequency mutated gene was identified as PARP14. RT-qPCR revealed significantly higher mRNA expression of PARP14 compared to precancerous tissue. Using IHC combined with Kaplan-Meier,patients in the PARP14 high expression group had a better prognosis than the low expression group. The study identified PARP14 as a frequently mutated gene in cervical cancer and proposed its potential role in diagnosis and treatment.

Natural Products Treat Colorectal Cancer by Regulating miRNA

Diseases are evolving as living standards continue to improve. Cancer is the main cause of death and a major public health problem that seriously threatens human life. Colorectal cancer is one of the top ten most common malignant tumors in China, ranking second after gastric cancer among gastrointestinal malignant tumors, and its incidence rate is increasing dramatically each year due to changes in the dietary habits and lifestyle of the world's population. Although conventional therapies, such as surgery, chemotherapy, and radiotherapy, have profoundly impacted the treatment of colorectal cancer (CRC), drug resistance and toxicity remain substantial challenges. Natural products, such as dietary therapeutic agents, are considered the safest alternative for treating CRC. In addition, there is substantial evidence that natural products can induce apoptosis, inhibit cell cycle arrest, and reduce the invasion and migration of colon cancer cells by targeting and regulating the expression and function of miRNAs. Here, we summarize the recent research findings on the miRNA-regulation-based antitumor mechanisms of various active ingredients in natural products, highlighting how natural products target miRNA regulation in colon cancer prevention and treatment. The application of natural drug delivery systems and predictive disease biomarkers in cancer prevention and treatment is also discussed. Such approaches will contribute to the discovery of new regulatory mechanisms associated with disease pathways and provide a new theoretical basis for developing novel colon cancer drugs and compounds and identifying new therapeutic targets.

NIAPU: network-informed adaptive positive-unlabeled learning for disease gene identification

MOTIVATION

Gene-disease associations are fundamental for understanding disease etiology and developing effective interventions and treatments. Identifying genes not yet associated with a disease due to a lack of studies is a challenging task in which prioritization based on prior knowledge is an important element. The computational search for new candidate disease genes may be eased by positive-unlabeled learning, the machine learning (ML) setting in which only a subset of instances are labeled as positive while the rest of the dataset is unlabeled. In this work, we propose a set of effective network-based features to be used in a novel Markov diffusion-based multi-class labeling strategy for putative disease gene discovery.

RESULTS

The performances of the new labeling algorithm and the effectiveness of the proposed features have been tested on 10 different disease datasets using three ML algorithms. The new features have been compared against classical topological and functional/ontological features and a set of network- and biological-derived features already used in gene discovery tasks. The predictive power of the integrated methodology in searching for new disease genes has been found to be competitive against state-of-the-art algorithms.

AVAILABILITY AND IMPLEMENTATION

The source code of NIAPU can be accessed at https://github.com/AndMastro/NIAPU. The source data used in this study are available online on the respective websites.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Radiotherapy prognosis-associated gene GCNT3 promotes the proliferation, migration and invasion of lung adenocarcinoma cells

Lung cancer is a life-threatening malignant tumour that is prevalent worldwide. Here, the GCNT3 gene in lung adenocarcinoma was studied via public databases, and cytology and molecular biology experiments were performed to further explore the role of this gene in lung adenocarcinoma. In this study, abnormally high GCNT3 expression levels were observed in tumour tissues compared with normal tissues at both the mRNA and protein levels. In the pancancer analysis, abnormal GCNT3 expression was observed in many tumour types. Moreover, the survival analysis revealed that among patients receiving radiotherapy, those with high GCNT3 expression levels had a worse prognosis. Cell and molecular biology experiments showed that the proliferation, migration and invasion capabilities of the A549 cell line were decreased after knockdown of GCNT3, and epithelial-mesenchymal transformation was significantly inhibited. In subsequent studies, we found that the sensitivity of cells to radiotherapy was enhanced after GCNT3 knockdown. Overall, our findings reveal that GCNT3 is an important factor affecting the radiotherapy sensitivity of lung adenocarcinoma, and GCNT3 inhibition deserves further study as a radiotherapy sensitising strategy.

Phenolic diterpenes from Rosemary supercritical extract inhibit non-small cell lung cancer lipid metabolism and synergise with therapeutic drugs in the clinic

Lung cancer is one of the most deadly and common cancers in the world. The molecular features of patient's tumours dictate the different therapeutic decisions, which combines targeted therapy, chemotherapy, and immunotherapy. Altered cellular metabolism is one of the hallmarks of cancer. Tumour cells reprogram their metabolism to adapt to their novel requirements of growth, proliferation, and survival. Together with the Warburg effect, the role of lipid metabolism alterations in cancer development and prognosis has been highlighted. Several lipid related genes have been shown to promote transformation and progression of cancer cells and have been proposed as biomarkers for prognosis. Nevertheless, the exact mechanisms of the regulation of lipid metabolism and the biological consequences in non-small cell lung cancer (NSCLC) have not been elucidated yet. There is an urgent necessity to develop multidisciplinary and complementary strategies to improve NSCLC patients´ well-being and treatment response. Nutrients can directly affect fundamental cellular processes and some diet-derived ingredients, bioactive natural compounds and natural extracts have been shown to inhibit the tumour growth in preclinical and clinical trials. Previously, we described a supercritical extract of rosemary (SFRE) (12 - 16% composition of phenolic diterpenes carnosic acid and carnosol) as a potential antitumoral agent in colon and breast cancer due to its effects on the inhibition of lipid metabolism and DNA synthesis, and in the reduction of resistance to 5-FluoroUracil (5-FU). Herein, we demonstrate SFRE inhibits NSCLC cell bioenergetics identifying several lipid metabolism implicated targets. Moreover, SFRE synergises with standard therapeutic drugs used in the clinic, such as cisplatin, pemetrexed and pembrolizumab to inhibit of cell viability of NSCLC cells. Importantly, the clinical relevance of SFRE as a complement in the treatment of NSCLC patients is suggested based on the results of a pilot clinical trial where SFRE formulated with bioactive lipids (PCT/ES2017/070263) diminishes metabolic and inflammatory targets in peripheral-blood mononuclear cells (PBMC), such as MAPK (p=0.04), NLRP3 (p=0.044), and SREBF1 (p=0.047), which may augment the immune antitumour function. Based on these results, SFRE merits further investigation as a co-adjuvant in the treatment of NSCLC.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT05080920.

Truncated lubricin glycans in osteoarthritis stimulate the synoviocyte secretion of VEGFA, IL-8, and MIP-1α: Interplay between O-linked glycosylation and inflammatory cytokines

The primary aim of the study was to identify inflammatory markers relevant for osteoarthritis (OA)-related systemic (plasma) and local (synovial fluid, SF) inflammation. From this, we looked for inflammatory markers that coincided with the increased amount of O-linked Tn antigen (GalNAcα1-Ser/Thr) glycan on SF lubricin. Inflammatory markers in plasma and SF in OA patients and controls were measured using a 44-multiplex immunoassay. We found consistently 29 markers detected in both plasma and SF. The difference in their concentration and the low correlation when comparing SF and plasma suggests an independent inflammatory environment in the two biofluids. Only plasma MCP-4 and TARC increased in our patient cohort compared to control plasma. To address the second task, we concluded that plasma markers were irrelevant for a direct connection with SF glycosylation. Hence, we correlated the SF-inflammatory marker concentrations with the level of altered glycosylation of SF-lubricin. We found that the level of SF-IL-8 and SF-MIP-1α and SF-VEGFA in OA patients displayed a positive correlation with the altered lubricin glycosylation. Furthermore, when exposing fibroblast-like synoviocytes from both controls and OA patients to glycovariants of recombinant lubricin, the secretion of IL-8 and MIP-1α and VEGFA were elevated using lubricin with Tn antigens, while lubricin with sialylated and nonsialylated T antigens had less or no measurable effect. These data suggest that truncated glycans of lubricin, as found in OA, promote synovial proinflammatory cytokine production and exacerbate local synovial inflammation.

Glycosyltransferase-related long non-coding RNA signature predicts the prognosis of colon adenocarcinoma

Purpose

Colon adenocarcinoma (COAD) is the most common type of colorectal cancer (CRC) and is associated with poor prognosis. Emerging evidence has demonstrated that glycosylation by long noncoding RNAs (lncRNAs) was associated with COAD progression. To date, however, the prognostic values of glycosyltransferase (GT)-related lncRNAs in COAD are still largely unknown.

Methods

We obtained the expression matrix of mRNAs and lncRNAs in COAD from The Cancer Genome Atlas (TCGA) database. Then, the univariate Cox regression analysis was conducted to identify 33 prognostic GT-related lncRNAs. Subsequently, LASSO and multivariate Cox regression analysis were performed, and 7 of 33 GT-related lncRNAs were selected to conduct a risk model. Gene set enrichment analysis (GSEA) was used to analyze gene signaling pathway enrichment of the risk model. ImmuCellAI, an online tool for estimating the abundance of immune cells, and correlation analysis were used to explore the tumor-infiltrating immune cells in COAD. Finally, the expression levels of seven lncRNAs were detected in colorectal cancer cell lines by reverse transcription-quantitative polymerase chain reaction (RT-qPCR).

Results

A total of 1,140 GT-related lncRNAs were identified, and 7 COAD-specific GT-related lncRNAs (LINC02381, MIR210HG, AC009237.14, AC105219.1, ZEB1-AS1, AC002310.1, and AC020558.2) were selected to conduct a risk model. Patients were divided into high- and low-risk groups based on the median of risk score. The prognosis of the high-risk group was worse than that of the low-risk group, indicating the good reliability and specificity of our risk model. Additionally, a nomogram based on the risk score and clinical traits was built to help clinical decisions. GSEA showed that the risk model was significantly enriched in metabolism-related pathways. Immune infiltration analysis revealed that five types of immune cells were significantly different between groups, and two types of immune cells were negatively correlated with the risk score. Besides, we found that the expression levels of these seven lncRNAs in tumor cells were significantly higher than those in normal cells, which verified the feasibility of the risk model.

Conclusion

The efficient risk model based on seven GT-related lncRNAs has prognostic potential for COAD, which may be novel biomarkers and therapeutic targets for COAD patients.

Functional analysis of GCNT3 for cell migration and EMT of castration-resistant prostate cancer cells

Castration-resistant prostate cancer (CRPC) is a malignant tumor that is resistant to androgen deprivation therapy. Treatments for CRPC are limited, and no diagnostic markers are currently available. O-glycans are known to play an important role in cell proliferation, migration, invasion, and metastasis of cancer cells. However, the differences in the O-glycan expression profiles for normal prostate cancer (PCa) cells compared to CRPC cells have not yet been investigated. In this study, the saccharide primer method was employed to analyze the O-glycans expressed in CRPC cells. Expression levels of core 4-type O-glycans were significantly increased in CRPC cells. Furthermore, the expression level of N-Acetylglucosaminyltransferase 3 (GCNT3), a core 4-type O-glycan synthase gene, was increased in CRPC cells. The expression of core 4-type O-glycans and GCNT3 was presumed to be regulated by androgen deprivation. GCNT3 knockdown induced cell migration and epithelial-mesenchymal transition (EMT). These observations elucidate the mechanism of acquisition of castration resistance in PCa and offer new possibilities for the development of diagnostic markers and therapeutic targets in the treatment of PCa.

LINC00511 enhances LUAD malignancy by upregulating GCNT3 via miR-195-5p

BACKGROUND

Accumulating evidence suggests that LINC00511 acts as an oncogenic long non-coding RNA (lncRNA) in various cancers, including lung adenocarcinoma (LUAD). Hence, we attempted to elucidate the potential role of LINC00511 in LUAD.

METHODS

LINC00511, miR-195-5p, and GCNT3 expression in LUAD was detected by qRT-PCR. Changes in the proliferation, migration, and invasion of LUAD cells after abnormal regulation of LINC00511, miR-195-5p, or GCNT3 were detected by CCK-8, BrdU, wound healing, and transwell assays. Bax and Bcl-2 protein expression was measured by western blotting. Additionally, we identified the targeting effects of LINC00511, miR-195-5p, and GCNT3 using luciferase and RNA immunoprecipitation (RIP) assays.

RESULTS

LINC00511 and GCNT3 were found to be upregulated in LUAD, while miR-195-5p was downregulated. Silencing LINC00511 or GCNT3 decreased the proliferation, migration, invasion, and Bcl-2 protein content in LUAD cells and increased the expression of Bax. Interference with miR-195-5p promoted malignant proliferation of cancer cells. miR-195-5p expression was affected by LINC00511and targeted GCNT3.

CONCLUSION

Silencing LINC00511 promotes GCNT3 expression by inhibiting miR-195-5p and ultimately stimulates the malignant progression of LUAD.

Metabolic Modifications, Inflammation, and Cancer Immunotherapy

Cancer immunotherapy has accomplished significant progresses on treatment of various cancers in the past decade; however, recent studies revealed more and more heterogeneity in tumor microenvironment which cause unneglectable therapy resistance. A central phenomenon in tumor malignancy is metabolic dysfunctionality; it reprograms metabolic homeostasis in tumor and stromal cells thus affecting metabolic modifications on specific proteins. These posttranslational modifications include glycosylation and palmitoylation, which usually alter the protein localization, stability, and function. Many of these proteins participate in acute or chronic inflammation and play critical roles in tumorigenesis and progression. Therefore, targeting these metabolic modifications in immune checkpoints and inflammation provides an attractive therapeutic strategy for certain cancers. In this review, we summarize the recent progresses on metabolic modifications in this field, focus on the mechanisms on how glycosylation and palmitoylation regulate innate immune and inflammation, and we further discuss designing new immunotherapy targeting metabolic modifications. We aim to improve immunotherapy or targeted-therapy response and achieve more accurate individual therapy.

Azurocidin is loaded into small extracellular vesicles via its N-linked glycosylation and promotes intravasation of renal cell carcinoma cells

Azurocidin (AZU1) is an antimicrobial protein secreted by neutrophils that acts as a chemoattractant for monocytes and macrophages and a permeabilizer of vascular endothelial cells. We previously identified AZU1 to be specifically present in extracellular vesicles (EVs) obtained from renal cell carcinoma (RCC) tissues. Here, we examined the relationship between N-linked glycosylation and AZU1 loading into small EVs (SEVs). Inhibition of N-linked glycosylation by introducing mutations in three glycosylation sites inhibited AZU1 loading into SEVs. Furthermore, SEVs released from AZU1-wild-type cells increased the Ca2+ concentration in endothelial cells and the endothelial permeability, whereas SEVs released from AZU1-mutant cells had no significant effect. Anti-AZU1 antibodies diminished the effect of SEVs on endothelial cell sheets. Collectively, we found that N-linked glycosylation of AZU1 directs its loading into SEVs, thereby enabling AZU1-positive SEVs to function as potent permeabilizers of endothelial cells and leading to enhanced transendothelial migration of RCC cells.

The Role of Glycosyltransferases in Colorectal Cancer

Colorectal cancer (CRC) is one of the main causes of cancer death in the world. Post-translational modifications (PTMs) have been extensively studied in malignancies due to its relevance in tumor pathogenesis and therapy. This review is focused on the dysregulation of glycosyltransferase expression in CRC and its impact in cell function and in several biological pathways associated with CRC pathogenesis, prognosis and therapeutic approaches. Glycan structures act as interface molecules between cells and their environment and in several cases facilitate molecule function. CRC tissue shows alterations in glycan structures decorating molecules, such as annexin-1, mucins, heat shock protein 90 (Hsp90), β1 integrin, carcinoembryonic antigen (CEA), epidermal growth factor receptor (EGFR), insulin-like growth factor-binding protein 3 (IGFBP3), transforming growth factor beta (TGF-β) receptors, Fas (CD95), PD-L1, decorin, sorbin and SH3 domain-containing protein 1 (SORBS1), CD147 and glycosphingolipids. All of these are described as key molecules in oncogenesis and metastasis. Therefore, glycosylation in CRC can affect cell migration, cell–cell adhesion, actin polymerization, mitosis, cell membrane repair, apoptosis, cell differentiation, stemness regulation, intestinal mucosal barrier integrity, immune system regulation, T cell polarization and gut microbiota composition; all such functions are associated with the prognosis and evolution of the disease. According to these findings, multiple strategies have been evaluated to alter oligosaccharide processing and to modify glycoconjugate structures in order to control CRC progression and prevent metastasis. Additionally, immunotherapy approaches have contemplated the use of neo-antigens, generated by altered glycosylation, as targets for tumor-specific T cells or engineered CAR (Chimeric antigen receptors) T cells.

Epstein-Barr Virus-Encoded Latent Membrane Protein 2A Downregulates GCNT3 via the TGF-β1/Smad-mTORC1 Signaling Axis

Increasing evidence shows that Epstein-Barr virus (EBV) infection is closely related to various lymphoid and epithelioid malignancies. However, the underlying mechanisms are unclear. GCNT3 (core 2β-1,6-acetylglucosaminyltransferase) is a new type of core mucin synthase, and its expression in EBV-associated gastric cancer (EBVaGC) is lower than that in EBV-negative gastric cancer (EBVnGC). EBV-encoded latent membrane protein 2A (LMP2A) is a transmembrane protein with tumorigenic transformation properties. Here, we demonstrated that LMP2A inhibited the transcription of GCNT3 by inhibiting Smad2/3 and Smad4. LMP2A restrained the activation of the mTORC1 pathway by inactivating the TGF-β1/Smad pathway and then downregulated GCNT3 expression. The mTORC1-GCNT3 pathway promoted cell proliferation and migration and inhibited G0/G1 cell arrest. Related proteins involved in epithelial-mesenchymal transition (EMT) were downstream molecules of the TGF-β1/Smad-mTORC1-GCNT3 pathway. GCNT3 inhibited autophagy by inducing mTORC1 phosphorylation. These findings indicate that targeting the TGF-β1/Smad-mTORC1-GCNT3 axis may represent a novel therapeutic target in GC.ImportanceEpstein-Barr virus (EBV) is an opportunistic pathogen, and the latent membrane protein 2A (LMP2A) encoded by EBV plays a key role in ensuring the incubation period of EBV. Glycosylation modification is an important marker of cancer cells, and recent studies have reported that it is related to EBV. Our conclusions provide deeper theoretical support for the role of LMP2A and TGF/Smad-mTORC1-GCNT3 in EBVaGC and help to understand glycosylation abnormalities in cancer. Our results may provide novel therapeutic targets for the treatment of gastric cancer against the TGF/Smad-mTORC1-GCNT3 signaling cascade.

Research progress on O-GlcNAcylation in the occurrence, development, and treatment of colorectal cancer

For a long time, colorectal cancer (CRC) has been ranked among the top cancer-related mortality rates, threatening human health. As a significant post-translational modification, O-GlcNAcylation plays an essential role in complex life activities. Related studies have found that the occurrence, development, and metastasis of CRC are all related to abnormal O-GlcNAcylation and participate in many critical biological processes, such as gene transcription, signal transduction, cell growth, and differentiation. Recently, nucleotide sugar analogs, tumor-specific carbohydrate vaccine, SIRT1 longevity gene, dendritic cells as targets, and NOTCH gene have become effective methods to induce antitumor therapy. Not long ago, checkpoint kinase 1 and checkpoint kinase 2 were used as therapeutic targets for CRC, but there are still many problems to be solved. With an in-depth study of protein chip, mass spectrometry, chromatography, and other technologies, O-GlcNAcylation research will accelerate rapidly, which may provide new ideas for the research and development of antitumor drugs and the discovery of new CRC diagnostic markers.

Colorectal cancer cell lines show striking diversity of their O-glycome reflecting the cellular differentiation phenotype

Alterations in protein glycosylation in colorectal cancer (CRC) have been extensively studied using cell lines as models. However, little is known about their O-glycome and the differences in glycan biosynthesis in different cell types. To provide a better understanding of the variation in O-glycosylation phenotypes and their association with other molecular features, an in-depth O-glycosylation analysis of 26 different CRC cell lines was performed. The released O-glycans were analysed on porous graphitized carbon nano-liquid chromatography system coupled to a mass spectrometer via electrospray ionization (PGC-nano-LC-ESI-MS/MS) allowing isomeric separation as well as in-depth structural characterization. Associations between the observed glycan phenotypes with previously reported cell line transcriptome signatures were examined by canonical correlation analysis. Striking differences are observed between the O-glycomes of 26 CRC cell lines. Unsupervized principal component analysis reveals a separation between well-differentiated colon-like and undifferentiated cell lines. Colon-like cell lines are characterized by a prevalence of I-branched and sialyl Lewis x/a epitope carrying glycans, while most undifferentiated cell lines show absence of Lewis epitope expression resulting in dominance of truncated α2,6-core sialylated glycans. Moreover, the expression of glycan signatures associates with the expression of glycosyltransferases that are involved in their biosynthesis, providing a deeper insight into the regulation of glycan biosynthesis in different cell types. This untargeted in-depth screening of cell line O-glycomes paves the way for future studies exploring the role of glycosylation in CRC development and drug response leading to discovery of novel targets for the development of anti-cancer antibodies.

Saponin-Rich Extracts and Their Acid Hydrolysates Differentially Target Colorectal Cancer Metabolism in the Frame of Precision Nutrition

Saponins or their aglycone form, sapogenin, have recently gained interest as bioactive agents due to their biological activities, their antitumoral effects being among them. Metabolic reprogramming has been recognized as a hallmark of cancer and, together with the increased aerobic glycolysis and glutaminolysis, the altered lipid metabolism is considered crucial to support cancer initiation and progression. The purpose of this study was to assess and compare the inhibitory effects on colorectal cancer cell lines of saponin-rich extracts from fenugreek and quinoa (FE and QE, respectively) and their hydrolyzed extracts as sapogenin-rich extracts (HFE and HQE, respectively). By mean of the latest technology in the analysis of cell bioenergetics, we demonstrate that FE and HFE diminished mitochondrial oxidative phosphorylation and aerobic glycolysis; meanwhile, quinoa extracts did not show relevant activities. Distinct molecular mechanisms were identified for fenugreek: FE inhibited the expression of TYMS1 and TK1, synergizing with the chemotherapeutic drug 5-fluorouracil (5-FU); meanwhile, HFE inhibited lipid metabolism targets, leading to diminished intracellular lipid content. The relevance of considering the coexisting compounds of the extracts or their hydrolysis transformation as innovative strategies to augment the therapeutic potential of the extracts, and the specific subgroup of patients where each extract would be more beneficial, are discussed in the frame of precision nutrition.

Metabolic enzyme ACSL3 is a prognostic biomarker and correlates with anticancer effectiveness of statins in non-small cell lung cancer

Lung cancer is one of the most common cancers, still characterized by high mortality rates. As lipid metabolism contributes to cancer metabolic reprogramming, several lipid metabolism genes are considered prognostic biomarkers of cancer. Statins are a class of lipid-lowering compounds used in treatment of cardiovascular disease that are currently studied for their antitumor effects. However, their exact mechanism of action and specific conditions in which they should be administered remains unclear. Here, we found that simvastatin treatment effectively promoted antiproliferative effects and modulated lipid metabolism-related pathways in non-small cell lung cancer (NSCLC) cells and that the antiproliferative effects of statins were potentiated by overexpression of acyl-CoA synthetase long-chain family member 3 (ACSL3). Moreover, ACSL3 overexpression was associated with worse clinical outcome in patients with high-grade NSCLC. Finally, we found that patients with high expression levels of ACSL3 displayed a clinical benefit of statins treatment. Therefore, our study highlights ACSL3 as a prognostic biomarker for NSCLC, useful to select patients who would obtain a clinical benefit from statin administration.

N-Glycome changes reflecting resistance to platinum-based chemotherapy in ovarian cancer

A number of studies have reported aberrant glycosylation in connection with malignancy. Our investigation further expands on this topic through the examination of N-glycans, which could be associated with the resistance of advanced stage, high-grade non-mucinous ovarian cancer to platinum/taxane based chemotherapy. We used tissue samples of 83 ovarian cancer patients, randomly divided into two independent cohorts (basic and validation). Both groups involved either cases with/without postoperative tumor residue or the cases determined either resistant or sensitive to this chemotherapy. In the validation cohort, preoperative serum samples were also available. N-glycans released from tumors and sera were permethylated and analyzed by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). The MS analysis yielded a consecutive detection of 68 (tissue) and 63 (serum) N-glycan spectral signals. Eight of these were found to be differentially abundant in tissues of both independent cohorts including the cases with a postoperative cancer residue. One of these glycans was detected as differentially abundant in sera of the validation cohort. No statistically significant differences in intensities due to the same N-glycans were found in the cases without postoperative macroscopic residues in either the basic or validation cohort. From the biochemical point of view, the statistically significant N-glycans correspond to the structures carrying bisecting (terminal) GlcNAc residue and tetra-antennary structures with sialic acid and/or fucose residues. Among them, six tissue N-glycans could be considered potential markers connected with a resistance to chemotherapy in ovarian cancer patients. The prediction of primary resistance to standard chemotherapy may identify the group of patients suitable for alternative treatment strategies. SIGNIFICANCE: Drug resistance has become a major impediment to a successful treatment of patients with advanced ovarian cancer. The glycomic measurements related to cancer are becoming increasingly popular in identification of the key molecules as potential diagnostic and prognostic indicators. Our report deals with identification of differences in N-glycosylation of proteins in tissue and serum samples from the individuals showing sensitivity or resistance to platinum/taxane-based chemotherapy. The detection sensitivity to chemotherapy is vitally important for these patients.

Overexpression of GLT1D1 induces immunosuppression through glycosylation of PD-L1 and predicts poor prognosis in B-cell lymphoma

B‐cell non‐Hodgkin's lymphoma (NHL) is a class of heterogeneous diseases with variable clinical outcomes. Immunosuppression is particularly common in the subtypes of lymphoma with poor prognosis, but the underlying mechanism remains unclear. Using a RT‐PCR array analysis, we have identified that glycosyltransferase 1 domain‐containing 1 (GLT1D1), an enzyme that transfers glycosyl groups to proteins, is highly upregulated in the incurable subtype of B‐cell NHL and in early relapse diffuse large B‐cell lymphoma. Analysis of clinical specimens revealed that GLT1D1 expression was positively correlated with the level of glycosylated programmed cell death‐ligand 1 (PD‐L1) in B‐cell NHL and that high GLT1D1 expression was associated with poor prognosis. Mechanistically, we showed that GLT1D1 transferred N‐linked glycans to PD‐L1, thus promoting the immunosuppressive function of glycosylated PD‐L1. Downregulation of GLT1D1 resulted in a decrease of glycosylated PD‐L1 and enhanced cytotoxic T‐cell function against lymphoma cells. In vivo, overexpression of GLT1D1 promoted tumor growth by facilitating tumor immune escape through increased levels of PD‐L1. Our work has identified GLT1D1 as a predictive biomarker for B‐cell NHL. It has also shown that this enzyme enhances PD‐L1 stabilization via N‐glycosylation, thus promoting immunosuppression and tumor growth. As such, GLT1D1 might be a novel therapeutic target for the treatment of B‐NHL.

OGT Controls the Expression and the Glycosylation of E-cadherin, and Affects Glycosphingolipid Structures in Human Colon Cell Lines

Colorectal cancer (CRC) affects both women and men living in societies with a high sedentary lifestyle. Amongst the phenotypic changes exhibited by tumor cells, a wide range of glycosylation has been reported for colon cancer-derived cell lines and CRC tissues. These aberrant modifications affect different aspects of glycosylation, including an increase in core fucosylation and GlcNAc branching on N-glycans, alteration of O-glycans, upregulated sialylation, and O-GlcNAcylation. Although O-GlcNAcylation and complex glycosylations differ in many aspects, sparse evidences report on the interference of O-GlcNAcylation with complex glycosylation. Nevertheless, this relationship is still a matter of debate. Combining different approaches on three human colon cell lines (HT29, HCT116 and CCD841CoN), it is herein reported that silencing O-GlcNAc transferase (OGT, the sole enzyme driving O-GlcNAcylation), only slightly affects overall N- and O-glycosylation patterns. Interestingly, silencing of OGT in HT29 cells upregulates E-cadherin (a major actor of epithelial-to-mesenchymal transition) and changes its glycosylation. On the other hand, OGT silencing perturbs biosynthesis of glycosphingolipids resulting in a decrease in gangliosides and an increase in globosides. Together, these results provide novel insights regarding the selective regulation of complex glycosylations by O-GlcNAcylation in colon cancer cells.

Phytochemical Modulation of MiRNAs in Colorectal Cancer

Colorectal cancer (CRC) is one of the leading causes of death in the United States. Chemotherapy and radiotherapy are some of the most commonly used treatments, but are often associated with severe side effects, and are not entirely curative. It is therefore important to consider other preventative treatment options. Phytochemicals are naturally occurring bioactive compounds which have been shown to play a role in cancer prevention and treatment, especially in regards to a person’s lifestyle and diet. Recent evidence has shown that phytochemicals may exert their chemopreventative effects by targeting micro RNAs (miRNAs), which regulate the downstream expression of tumor suppressors and oncogenes. MiRNAs are small, endogenous, noncoding RNAs that regulate several biological processes through post-translational regulation. The dysregulation of miRNA expression has been shown to be associated with colorectal cancer. In this review, we will summarize and discuss several phytochemicals, which have been shown to exert chemopreventative effects in colorectal cancer by the modulation of miRNA expression.