C1GALT1, Negatively Regulated by miR-181d-5p, Promotes Tumor Progression via Upregulating RAC1 in Lung Adenocarcinoma

C1GALT1 induces the carcinogenesis of thyroid cancer through regulation by miR-141-3p and GLUT1

Core 1 β 1,3-galactosyltransferase 1 (C1GALT1) acts as an important glycosyltransferase in the occurrence and development of tumor glycosylation. However, the regulatory mechanisms of C1GALT1 in thyroid cancer (TC) is still unclear. In this study, we discovered that the expression level of C1GALT1 was significantly increased in thyroid adenocarcinoma tissues and cell lines (p < 0.01). Meanwhile, gene silencing of C1GALT1 inhibited the proliferation (CCK-8 assay), migration (wound healing), and invasion (Transwell) of TC cells (p < 0.05). Further investigation indicated that miR-141-3p had a negative correlation with C1GALT1 and suppressed cancer carcinogenesis in TC cells. Moreover, we first found that glucose transporter 1 (GLUT1) was a downstream element of C1GALT1 and was positively correlated with C1GALT1 levels in TC. The GLUT1 could reverse the inhibitory effects of siRNA C1GALT1 on cell development (p < 0.05). These data suggest that the miR-141-3p/C1GALT1/GLUT1 axis plays an essential role during TC progression and may be a probable biomarker or therapeutic target for thyroid cancer patients.

Identification and validation of a glycosyltransferase gene signature as a novel prognostic model for lung adenocarcinoma

Background

The role of glycosyltransferase (GT) genes in lung adenocarcinoma (LUAD) needs further elucidation. Thus, our study aims to identify the prognostic gene signature of LUAD and explore its molecular functions.

Methods

We initially extracted GT gene sets from the database, and obtained mRNA expression levels and clinical data from The Cancer Genome Atlas (TCGA) database. For constructing a prognostic model for GT genes, we utilized univariate, least absolute shrinkage and selection operator (LASSO), and multivariate Cox regression analyses. Using the model, patients were categorized into high- and low-risk groups. Additionally, we evaluated differences in tumor immune infiltration between these groups and identified potential therapeutic drugs. Finally, we experimentally validated the expression levels of these crucial prognostic genes.

Results

We developed a risk score comprising nine GT genes (C1GALT1, FUT1, GALNT2, PLOD2, POMK, PYGB, ST3GAL6, UGT2B11, UGT3A1). Patients were then categorized into low- and high-risk groups based on this score. The low-risk group showed superior overall survival (OS) compared to the high-risk group. There were significantly distinct tumor immune microenvironment statuses observed between the two groups. We identified potential therapeutic drugs, including the MEK inhibitor (PD-184352). Finally, we verified the expression of these nine GT genes through immunohistochemistry (IHC) staining and quantitative real-time PCR (qPCR).

Conclusion

We identified a distinct LUAD GT gene signature, and these differentially expressed mRNAs could serve as valuable prognostic biomarkers and therapeutic targets. Furthermore, we experimentally validated their expression levels and identified potential therapeutic agents.

High core 1β1,3-galactosyltransferase 1 expression is associated with poor prognosis and promotes cellular radioresistance in lung adenocarcinoma

PURPOSE

Core 1β1,3-galactosyltransferase 1 (C1GALT1) exhibits elevated expression in multiple cancers. The present study aimed to elucidate the clinical significance of C1GALT1 aberrant expression and its impact on radiosensitivity in lung adenocarcinoma (LUAD).

METHODS

The C1GALT1 expression and its clinical relevance were investigated through public databases and LUAD tissue microarray analyses. A549 and H1299 cells with either C1GALT1 knockdown or overexpression were further assessed through colony formation, gamma-H2A histone family member X immunofluorescence, 5-ethynyl-2'-deoxyuridine incorporation, and flow cytometry assays. Bioinformatics analysis was used to explore single cell sequencing data, revealing the influence of C1GALT1 on cancer-associated cellular states. Vimentin, N-cadherin, and E-cadherin protein levels were measured through western blotting.

RESULTS

The expression of C1GALT1 was significantly higher in LUAD tissues than in adjacent non-tumor tissues both at mRNA and protein level. High expression of C1GALT1 was correlated with lymph node metastasis, advanced T stage, and poor survival, and was an independent risk factor for overall survival. Radiation notably upregulated C1GALT1 expression in A549 and H1299 cells, while radiosensitivity was increased following C1GALT1 knockdown and decreased following overexpression. Experiment results showed that overexpression of C1GALT1 conferred radioresistance, promoting DNA repair, cell proliferation, and G2/M phase arrest, while inhibiting apoptosis and decreasing E-cadherin expression, alongside upregulating vimentin and N-cadherin in A549 and H1299 cells. Conversely, C1GALT1 knockdown had opposing effects.

CONCLUSION

Elevated C1GALT1 expression in LUAD is associated with an unfavorable prognosis and contributes to increased radioresistance potentially by affecting DNA repair, cell proliferation, cell cycle regulation, and epithelial-mesenchymal transition (EMT).

A MiR181/Sirtuin1 regulatory circuit modulates drug response in biliary cancers

Despite recent advances, biliary tract cancer (BTC) remains one of the most lethal tumor worldwide due to late diagnosis, limited therapeutic strategies and resistance to conventional therapies. In recent years, high-throughput technologies have enabled extensive genome, and transcriptome sequencing unveiling, among others, the regulatory potential of microRNAs (miRNAs). Compelling evidence shown that miRNA are attractive therapeutic targets and promising candidates as biomarkers for various therapy-resistant tumors. The analysis of miRNA profile successfully identified miR-181c and -181d as significantly downregulated in BTC patients. Low miR-181c and -181d expression levels were correlated with worse prognosis and poor treatment efficacy. In fact, progression-free survival analysis indicated poor survival rates in miR-181c and -181d low expressing patients. The expression profile of miR-181c and -181d in BTC cell lines revealed that both miRNAs were dysregulated. Functional in vitro experiments in BTC cell lines showed that overexpression of miR-181c and -181d affected cell viability and increased sensitivity to chemotherapy compared to controls. In addition, by using bioinformatic tools we showed that the miR-181c/d functional role is determined by binding to their target SIRT1 (Sirtuin 1). Moreover, BTC patients expressing high levels of miR-181 and low SIRT1 shown an improved survival and treatment response. An integrative network analysis demonstrated that, miR-181/SIRT1 circuit had a regulatory effect on several important metabolic tumor-related processes. Our study demonstrated that miR-181c and -181d act as tumor suppressor miRNA in BTC, suggesting the potential use as therapeutic strategy in resistant cancers and as predictive biomarker in the precision medicine of BTC.

The oncogenic role and regulatory mechanism of PGK1 in human non-small cell lung cancer

BACKGROUND

Phosphoglycerate kinase 1 (PGK1) is a metabolic enzyme that participates in various biological and pathological processes. Dysregulated PGK1 has been observed in numerous malignancies. However, whether and how PGK1 affects non-small cell lung cancer (NSCLC) is not yet fully elucidated.

METHODS

Herein, the non-metabolic function of PGK1 in NSCLC was explored by integrating bioinformatics analyses, cellular experiments, and nude mouse xenograft models. The upstream regulators and downstream targets of PGK1 were examined using multiple techniques such as RNA sequencing, a dual-luciferase reporter assay, Co-immunoprecipitation, and Western blotting.

RESULTS

We confirmed that PGK1 was upregulated in NSCLC and this upregulation was associated with poor prognosis. Further in vitro and in vivo experiments demonstrated the promoting effects of PGK1 on NSCLC cell growth and metastasis. Additionally, we discovered that PGK1 interacted with and could be O-GlcNAcylated by OGT. The inhibition of PGK1 O-GlcNAcylation through OGT silencing or mutation at the T255 O-GlcNAcylation site could weaken PGK1-mediated NSCLC cell proliferation, colony formation, migration, and invasion. We also found that a low miR-24-3p level led to an increase in OGT expression. Additionally, PGK1 exerted its oncogenic properties by augmenting ERK phosphorylation and MCM4 expression.

CONCLUSIONS

PGK1 acted as a crucial mediator in controlling NSCLC progression. The miR-24-3p/OGT axis was responsible for PGK1 O-GlcNAcylation, and ERK/MCM4 were the downstream effectors of PGK1. It appears that PGK1 might be an attractive therapeutic target for the treatment of NSCLC.

C1GalT1 expression reciprocally controls tumour cell-cell and tumour-macrophage interactions mediated by galectin-3 and MGL with double impact on cancer development and progression

Although most cell membrane proteins are modified by glycosylation, our understanding of the role and actions of protein glycosylation is still very limited. β1,3galactosyltransferase (C1GalT1) is a key glycosyltransferase that controls the biosynthesis of the Core 1 structure of O-linked mucin type glycans and is overexpressed by many common types of epithelial cancers. This study reports that suppression of C1GalT1 expression in human colon cancer cells caused substantial changes of protein glycosylation of cell membrane proteins, many of which were ligands of the galactoside-binding galectin-3 and the macrophage galactose-type lectin (MGL). This led to significant reduction of cancer cell proliferation, adhesion, migration and the ability of tumour cells to form colonies. Crucially, C1GalT1 suppression significantly reduced galectin-3-mediated tumour cell-cell interaction and galectin-3-promoted tumour cell activities. In the meantime, C1GalT1 suppression substantially increased MGL-mediated macrophage-tumour cell interaction and macrophage-tumour cell phagocytosis and cytokine secretion. C1GalT1-expressing cancer cells implanted in chick embryos resulted in the formation of significantly bigger tumours than C1GalT1-suppressed cells and the presence of galectin-3 increased tumour growth of C1GalT1-expressing but not C1GalT1-suppressed cells. More MGL-expressing macrophages and dendritic cells were seen to be attracted to the tumour microenvironment in ME C1galt1-/-/Erb mice than in C1galt1f/f /Erb mice. These results indicate that expression of C1GalT1 by tumour cells reciprocally controls tumour cell-cell and tumour-macrophage interactions mediated by galectin-3 and MGL with double impact on cancer development and progression. C1GalT1 overexpression in epithelial cancers therefore may represent a fundamental mechanism in cancer promotion and in reduction of immune response/surveillance in cancer progression.

In-depth quantitative proteomics analysis revealed C1GALT1 depletion in ECC-1 cells mimics an aggressive endometrial cancer phenotype observed in cancer patients with low C1GALT1 expression

BACKGROUND

Endometrial cancer (EC) is the most common cancer of the female reproductive organs. Despite the good overall prognosis of most low-grade ECs, FIGO I and FIGO II patients might experience tumor recurrence and worse prognosis. The study of alterations related to EC pathogenesis might help to get insights into underlying mechanisms involved in EC development and progression.

METHODS

Core tumoral samples were used to investigate the role of C1GALT1 in EC by immunohistochemistry (IHC). ECC-1 cells were used as endometrioid EC model to investigate the effect of C1GALT1 depletion using C1GALT1 specific shRNAs. SILAC quantitative proteomics analyses and cell-based assays, PCR, qPCR, WB, dot-blot and IHC analyses were used to identify, quantify and validate dysregulation of proteins.

RESULTS

Low C1GALT1 protein expression levels associate to a more aggressive phenotype of EC. Out of 5208 proteins identified and quantified by LC-MS/MS, 100 proteins showed dysregulation (log₂fold-change ≥ 0.58 or ≤-0.58) in the cell protein extracts and 144 in the secretome of C1GALT1 depleted ECC-1 cells. Nine dysregulated proteins were validated. Bioinformatics analyses pointed out to an increase in pathways associated with an aggressive phenotype. This finding was corroborated by loss-of-function cell-based assays demonstrating higher proliferation, invasion, migration, colony formation and angiogenesis capacity in C1GALT1 depleted cells. These effects were associated to the overexpression of ANXA1, as demonstrated by ANXA1 transient silencing cell-based assays, and thus, correlating C1GALT and ANXA1 protein expression and biological effects. Finally, the negative protein expression correlation found by proteomics between C1GALT1 and LGALS3 was confirmed by IHC.

CONCLUSION

C1GALT1 stably depleted ECC-1 cells mimic an EC aggressive phenotype observed in patients and might be useful for the identification and validation of EC markers of progression.

The Mutual Relationship between Glycosylation and Non-Coding RNAs in Cancer and Other Physio-Pathological Conditions

Glycosylation, which consists of the enzymatic addition of sugars to proteins and lipids, is one of the most important post-co-synthetic modifications of these molecules, profoundly affecting their activity. Although the presence of carbohydrate chains is crucial for fine-tuning the interactions between cells and molecules, glycosylation is an intrinsically stochastic process regulated by the relative abundance of biosynthetic (glycosyltransferases) and catabolic (glycosidases) enzymes, as well as sugar carriers and other molecules. Non-coding RNAs, which include microRNAs, long non-coding RNAs and circRNAs, establish a complex network of reciprocally interacting molecules whose final goal is the regulation of mRNA expression. Likewise, these interactions are stochastically regulated by ncRNA abundance. Thus, while protein sequence is deterministically dictated by the DNA/RNA/protein axis, protein abundance and activity are regulated by two stochastic processes acting, respectively, before and after the biosynthesis of the protein axis. Consequently, the worlds of glycosylation and ncRNA are closely interconnected and mutually interacting. In this paper, we will extensively review the many faces of the ncRNA-glycosylation interplay in cancer and other physio-pathological conditions.

Upregulation of circ_0035266 contributes to the malignant progression of inflammation-associated malignant transformed cells induced by tobacco-specific carcinogen NNK

Cigarette smoking-induced chronic inflammation has been considered a vital driver of lung tumorigenesis. The compounds 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a tobacco-specific carcinogen, and lipopolysaccharide (LPS), an inflammatory inducer, are important components of tobacco smoke which have been implicated in inflammation-driven carcinogenesis. However, the biological effects and underlying mechanisms of LPS-mediated inflammation on NNK-induced tumorigenesis are still unclear. In this study, BEAS-2B human bronchial epithelial cells were exposed to NNK, LPS or both, for short- or long-term periods. We found that acute LPS exposure promoted the secretion of granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin (IL)-6 in NNK-treated BEAS-2B cells. In addition, chronic LPS exposure facilitated the NNK-induced malignant transformation process by promoting cell proliferation, cell cycle alteration, migration and clonal formation. Previously, we determined that circular RNA circ_0035266 enhanced cellular inflammation in response to NNK+LPS by sponging miR-181d-5p and regulating expression of its downstream target DEAD-Box Helicase 3 X-Linked (DDX3X). Here, we found that knockdown of circ_0035266 or DDX3X led to a remarkable inhibition of the proliferation, cell cycle progression and migration of NNK+LPS-transformed BEAS-2B cells, while overexpression of these genes produced the opposite effects, indicating the oncogenic roles of circ_0035266 and DDX3X in the malignant progression of chronic inflammation-driven malignant transformed cells. Moreover, the regulatory relationships among circ_0035266, miR-181d-5p and DDX3X were further confirmed using a group of lung cancer tissues. Conclusively, our findings provide novel insights into our understanding of inflammation-driven tumorigenesis using a cellular malignant transformation model, and indicate a novel tumor-promoting role for circ_0035266 in chemical carcinogenesis.

Update on the role of C1GALT1 in cancer (Review)

Cancer remains one of the most difficult diseases to treat. In the quest for early diagnoses to improve patient survival and prognosis, targeted therapies have become a hot research topic in recent years. Glycosylation is the most common posttranslational modification in mammalian cells. Core 1β1,3-galactosyltransferase (C1GALT1) is a key glycosyltransferase in the glycosylation process and is the key enzyme in the formation of the core 1 structure on which most complex and branched O-glycans are formed. A recent study reported that C1GALT1 was aberrantly expressed in tumors. In cancer cells, C1GALT1 is regulated by different factors. In the present review, the expression of C1GALT1 in different tumors and its possible molecular mechanisms of action are described and the role of C1GALT1 in cancer development is discussed.

Expression and Impact of C1GalT1 in Cancer Development and Progression

Simple Summary

C1GalT1 is one of the enzymes that catalyze the addition of sugar residues to proteins (protein glycosylation). It specifically controls the synthesis and formation of a special disaccharide structure Galβ1,3GalNAcα-, which occurs predominately in cancer but rarely in normal cells. Recent studies have shown that C1GalT1 is overexpressed in many common cancers including colon, breast, gastric, lung, head and neck, pancreatic, esophageal, prostate, and hepatocellular cancer. C1GalT1 overexpression is also often associated with poorer prognosis and poorer patient survival. This review summarizes our current understanding of the expression of C1GalT1 in various cancers and discusses the impact of C1GalT change on cancer cell activities in cancer development and progression.

Abstract

C1GalT1 (T-synthase) is one of the key glycosyltransferases in the biosynthesis of O-linked mucin-type glycans of glycoproteins. It controls the formation of Core-1 disaccharide Galβ1,3GalNAcα- (Thomsen–Friedenreich oncofetal antigen, T or TF antigen) and Core-1-associated carbohydrate structures. Recent studies have shown that C1GalT1 is overexpressed in many cancers of epithelial origin including colon, breast, gastric, head and neck, pancreatic, esophageal, prostate, and hepatocellular cancer. Overexpression of C1GalT1 is often seen to also be associated with poorer prognosis and poorer patient survival. Change of C1GalT1 expression causes glycosylation changes of many cell membrane glycoproteins including mucin proteins, growth factor receptors, adhesion molecules, and death receptors. This leads to alteration of the interactions of these cell surface molecules with their binding ligands, resulting in changes of cancer cell activity and behaviors. This review summarizes our current understanding of the expression of C1GalT1 in various cancers and discusses the impact of C1GalT change on cancer cell activities in cancer development and progression.

Hsa_circRNA_0045861 promotes renal injury in ureteropelvic junction obstruction via the microRNA-181d-5p/sirtuin 1 signaling axis

Background

Ureteropelvic junction obstruction (UPJO) is one of the most common causes of hydronephrosis in children. This study explored the effects and the regulatory mechanisms of the circular RNA (circRNA) hsa_circRNA_0045861 (circRNA_0045861) in UPJO.

Methods

RNA sequencing was used to identify the differentially expressed circRNAs in UPJO. The effects of circRNA_0045861 on renal cell apoptosis was investigated by flow cytometry and Western blot analysis. Furthermore, we used bioinformatics methods to predict the possible target genes of circRNA_0045861. Fluorescence in-situ hybridization and dual-luciferase reporter assays were performed to validate the target genes of circRNA_0045861. Finally, we evaluated the effects of circRNA_0045861 target gene miR-181d-5p on UPJO-induced renal fibrosis in vivo.

Results

RNA sequencing identified 63 upregulated and 64 downregulated circRNAs in UPJO patients. The expression of circRNA_0045861 was significantly elevated in kidney damage both in vivo and in vitro. Silencing circ_0045861 inhibited transforming growth factor (TGF)-β1-induced apoptosis in vitro in human kidney 2 (HK-2) cells. Furthermore, circ_0045861 was shown to directly interact with the microRNA miR-181d-5p and regulate the expression of sirtuin 1 (SIRT1), thereby promoting the progression of apoptosis and renal injury. In addition, overexpression of miR-181d-5p inhibited cell apoptosis and renal fibrosis in a mouse model through downregulating the SIRT1/p53 pathway.

Conclusions

Circ_0045861 may be a novel candidate circRNA in the pathogenesis of UPJO by acting as a pro-apoptotic factor via the miR-181d-5p/SIRT1 axis.