Knockdown of C1GalT1 inhibits radioresistance of human esophageal cancer cells through modifying β1-integrin glycosylation

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).

Nitric Oxide-Scavenging, Anti-Migration Effects, and Glycosylation Changes after Hemin Treatment of Human Triple-Negative Breast Cancer Cells: A Mechanistic Study

The enhanced expression of nitric oxide (•NO) synthase predicts triple-negative breast cancer outcome and its resistance to different therapeutics. Our earlier work demonstrated the efficiency of hemin to scavenge the intra- and extracellular •NO, proposing its potency as a therapeutic agent for inhibiting cancer cell migration. In continuation, the present work evaluates the effects of •NO on the migration of MDA-MB-231 cells and how hemin modulates the accompanied cellular behavior, focusing on the corresponding expression of cellular glycoproteins, migration-associated markers, and mitochondrial functions. We demonstrated for the first time that while •NO induced cell migration, hemin contradicted that by •NO-scavenging. This was in combination with modulation of the •NO-enhanced glycosylation patterns of cellular proteins with inhibition of the expression of specific proteins involved in the epithelial-mesenchymal transition. These effects were in conjunction with changes in the mitochondrial functions related to both •NO, hemin, and its nitrosylated product. Together, these results suggest that hemin can be employed as a potential anti-migrating agent targeting •NO-scavenging and regulating the expression of migration-associated proteins.

Dual effects of radiotherapy on tumor microenvironment and its contribution towards the development of resistance to immunotherapy in gastrointestinal and thoracic cancers

Successful clinical methods for tumor elimination include a combination of surgical resection, radiotherapy, and chemotherapy. Radiotherapy is one of the crucial components of the cancer treatment regimens which allow to extend patient life expectancy. Current cutting-edge radiotherapy research is focused on the identification of methods that should increase cancer cell sensitivity to radiation and activate anti-cancer immunity mechanisms. Radiation treatment activates various cells of the tumor microenvironment (TME) and impacts tumor growth, angiogenesis, and anti-cancer immunity. Radiotherapy was shown to regulate signaling and anti-cancer functions of various TME immune and vasculature cell components, including tumor-associated macrophages, dendritic cells, endothelial cells, cancer-associated fibroblasts (CAFs), natural killers, and other T cell subsets. Dual effects of radiation, including metastasis-promoting effects and activation of oxidative stress, have been detected, suggesting that radiotherapy triggers heterogeneous targets. In this review, we critically discuss the activation of TME and angiogenesis during radiotherapy which is used to strengthen the effects of novel immunotherapy. Intracellular, genetic, and epigenetic mechanisms of signaling and clinical manipulations of immune responses and oxidative stress by radiotherapy are accented. Current findings indicate that radiotherapy should be considered as a supporting instrument for immunotherapy to limit the cancer-promoting effects of TME. To increase cancer-free survival rates, it is recommended to combine personalized radiation therapy methods with TME-targeting drugs, including immune checkpoint inhibitors.

TMTC1 promotes invasiveness of ovarian cancer cells through integrins β1 and β4

Ovarian cancer is the most lethal gynecological malignancy and is characterized by peritoneal disseminated metastasis. Although O-mannosyltransferase TMTC1 is highly expressed by ovarian cancer, its pathophysiological role in ovarian cancer remains unclear. Here, immunohistochemistry showed that TMTC1 was overexpressed in ovarian cancer tissues compared with adjacent normal ovarian tissues, and high TMTC1 expression was associated with poor prognosis in patients with ovarian cancer. Silencing TMTC1 reduced ovarian cancer cell viability, migration, and invasion in vitro, as well as suppressed peritoneal tumor growth and metastasis in vivo. Moreover, TMTC1 knockdown reduced cell-laminin adhesion, which was associated with the decreased phosphorylation of FAK at pY397. Conversely, TMTC1 overexpression promoted these malignant properties in ovarian cancer cells. Glycoproteomic analysis and Concanavalin A (ConA) pull-down assays showed that integrins β1 and β4 were novel O-mannosylated protein substrates of TMTC1. Furthermore, TMTC1-mediated cell migration and invasion were significantly reversed by siRNA-mediated knockdown of integrin β1 or β4. Collectively, these results suggest that TMTC1-mediated invasive behaviors are primarily through integrins β1 and β4 and that TMTC1 is a potential therapeutic target for ovarian cancer.

Dysregulation and prometastatic function of glycosyltransferase C1GALT1 modulated by cHP1BP3/ miR-1-3p axis in bladder cancer

Background

Abnormal glycosylation in a variety of cancer types is involved in tumor progression and chemoresistance. Glycosyltransferase C1GALT1, the key enzyme in conversion of Tn antigen to T antigen, is involved in both physiological and pathological conditions. However, the mechanisms of C1GALT1 in enhancing oncogenic phenotypes and its regulatory effects via non-coding RNA are unclear.

Methods

Abnormal expression of C1GALT1 and its products T antigen in human bladder cancer (BLCA) were evaluated with BLCA tissue, plasma samples and cell lines. Effects of C1GALT1 on migratory ability and proliferation were assessed in YTS-1 cells by transwell, CCK8 and colony formation assay in vitro and by mouse subcutaneous xenograft and trans-splenic metastasis models in vivo. Dysregulated circular RNAs (circRNAs) and microRNAs (miRNAs) were profiled in 3 pairs of bladder cancer tissues by RNA-seq. Effects of miR-1-3p and cHP1BP3 (circRNA derived from HP1BP3) on modulating C1GALT1 expression were investigated by target prediction program, correlation analysis and luciferase reporter assay. Functional roles of miR-1-3p and cHP1BP3 on migratory ability and proliferation in BLCA were also investigated by in vitro and in vivo experiments. Additionally, glycoproteomic analysis was employed to identify the target glycoproteins of C1GALT1.

Results

In this study, we demonstrated upregulation of C1GALT1 and its product T antigen in BLCA. C1GALT1 silencing suppressed migratory ability and proliferation of BLCA YTS-1 cells in vitro and in vivo. Subsets of circRNAs and miRNAs were dysregulated in BLCA tissues. miR-1-3p, which is reduced in BLCA tissues, inhibited transcription of C1GALT1 by binding directly to its 3′-untranslated region (3′-UTR). miR-1-3p overexpression resulted in decreased migratory ability and proliferation of YTS-1 cells. cHP1BP3 was upregulated in BLCA tissues, and served as an miR-1-3p “sponge”. cHP1BP3 was shown to modulate migratory ability, proliferation, and colony formation of YTS-1 cells, and displayed tumor-suppressing activity in BLCA. Target glycoproteins of C1GALT1, including integrins and MUC16, were identified.

Conclusions

This study reveals the pro-metastatic and proliferative function of upregulated glycosyltransferase C1GLAT1, and provides preliminary data on mechanisms underlying dysregulation of C1GALT1 via miR-1-3p / cHP1BP3 axis in BLCA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-022-02438-7.

Galectins in Esophageal Cancer: Current Knowledge and Future Perspectives

Esophageal cancer is a disease with poor overall survival. Despite advancements in therapeutic options, the treatment outcome of esophageal cancer patients remains dismal with an overall 5-year survival rate of approximately 20 percent. To improve treatment efficacy and patient survival, efforts are being made to identify the factors that underlie disease progression and that contribute to poor therapeutic responses. It has become clear that some of these factors reside in the tumor micro-environment. In particular, the tumor vasculature and the tumor immune micro-environment have been implicated in esophageal cancer progression and treatment response. Interestingly, galectins represent a family of glycan-binding proteins that has been linked to both tumor angiogenesis and tumor immunosuppression. Indeed, in several cancer types, galectins have been identified as diagnostic and/or prognostic markers. However, the role of galectins in esophageal cancer is still poorly understood. Here, we summarize the current literature with regard to the expression and potential functions of galectins in esophageal cancer. In addition, we highlight the gaps in the current knowledge and we propose directions for future research in order to reveal whether galectins contribute to esophageal cancer progression and provide opportunities to improve the treatment and survival of esophageal cancer patients.

A Sweet Warning: Mucin-Type O-Glycans in Cancer

Glycosylation is a common post-translational modification process of proteins. Mucin-type O-glycosylation is an O-glycosylation that starts from protein serine/threonine residues. Normally, it is involved in the normal development and differentiation of cells and tissues, abnormal glycosylation can lead to a variety of diseases, especially cancer. This paper reviews the normal biosynthesis of mucin-type O-glycans and their role in the maintenance of body health, followed by the mechanisms of abnormal mucin-type O-glycosylation in the development of diseases, especially tumors, including the effects of Tn, STn, T antigen, and different glycosyltransferases, with special emphasis on their role in the development of gastric cancer. Finally, tumor immunotherapy targeting mucin-type O-glycans was discussed.

miR-498/DNMT3b Axis Mediates Resistance to Radiotherapy in Esophageal Cancer Cells

Objective: To explore the role of miR-498 in the radiotherapy resistance of esophageal cancer (EC) and its underlying mechanism. Methods: In vivo models of EC tissues with radioresistance or radiosensitivity were isolated from 72 EC patients who received radiotherapy. In vitro models were established after irradiation of KYSE30 cells. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot were employed to measure the expression levels of miR-498 and DNMT3b in EC cells sensitive or resistant to irradiation. Then, protein expression of DNMT3b was verified by immunohistochemistry. The cell viability, colony formation rate, and cell apoptotic rate of EC were correspondingly assessed by CCK-8, colony formation assay, and Annexin V/PI (propidium iodide) double staining. Western blot was utilized to perform the expression levels of PI3K, p-PI3K, AKT, and p-AKT in EC cell lines after irradiation. Results: Highly expressed DNMT3b and lowly expressed miR-498 were found in EC tissues. EC tissues with radiosensitivity had higher miR-498 level and lower DNMT3b expression than EC tissues with radioresistance. Overexpression of miR-498 or knockdown of DNMT3b enhanced the radiosensitivity of EC cells. DNMT3b was a target gene of miR-498. DNMT3b diminished the radiosensitization of miR-498 in EC cells. Conclusions: MiR-498 enhances the sensitivity of EC cells to radiation by DNMT3b inhibition, and exerts biological functions by inactivating the PI3K/AKT signaling pathway.

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.

Down-Regulation of C1GALT1 Enhances the Progression of Cholangiocarcinoma through Activation of AKT/ERK Signaling Pathways

Alteration of mucin-type O-glycosylation is implicated in tumor progression and metastasis of cholangiocarcinoma (CCA). Core 1 β1-3 Galactosyltransferase (C1GALT1) is a primary enzyme that regulates the elongation of core 1-derived mucin-type O-glycans. Dysregulation of C1GALT1 has been documented in multiple cancers and is associated with aberrant core 1 O-glycosylation and cancer aggressiveness; however, the expression of C1GALT1 and its role in CCA progression remains unknown. Our study demonstrated that C1GALT1 was downregulated in CCA tissues at both the mRNA and protein levels. The biological function of C1GALT1 using siRNA demonstrated that suppression of C1GALT1 in the CCA cell lines (KKU-055 and KKU-100) increased CCA progression, evidenced by: (i) Induction of CCA cell proliferation and 5-fluorouracil resistance in a dose-dependent manner; (ii) up-regulation of growth-related genes, ABC transporter genes, and anti-apoptotic proteins; and (iii) an increase in the activation/phosphorylation of AKT and ERK in silencing C1GALT1 cells. We demonstrated that silencing C1GALT1 in CCA cell lines was associated with immature core 1 O-glycosylation, demonstrated by high expression of VVL-binding glycans and down-regulation of other main O-linked glycosyltransferases β1,3-N-acetylglucosaminyltransferase 6 (B3GNT6) and ST6 N-Acetylgalactosaminide Alpha-2,6-Sialyltransferase 1 (ST6GALNAC1) in C1GALT1 knockdown. Our findings demonstrate that down-regulation of C1GALT1 in CCA increases the expression of immature core 1 O-glycan, enhancing CCA progression, including growth and 5-fluorouracil resistance via the activation of the AKT/ERK signaling pathway.

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.

C1GALT1 in health and disease

O-linked glycosylation (O-glycosylation) and N-linked glycosylation (N-glycosylation) are the two most important forms of protein glycosylation, which is an important post-translational modification. The regulation of protein function involves numerous mechanisms, among which protein glycosylation is one of the most important. Core 1 synthase glycoprotein-N-acetylgalactosamine 3-β-galactosyltransferase 1 (C1GALT1) serves an important role in the regulation of O-glycosylation and is an essential enzyme for synthesizing the core 1 structure of mucin-type O-glycans. Furthermore, C1GALT1 serves a vital role in a number of biological functions, such as angiogenesis, platelet production and kidney development. Impaired C1GALT1 expression activity has been associated with different types of human diseases, including inflammatory or immune-mediated diseases, and cancer. O-glycosylation exists in normal tissues, as well as in tumor tissues. Previous studies have revealed that changes in the level of glycosyltransferase in different types of cancer may be used as potential therapeutic targets. Currently, numerous studies have reported the dual role of C1GALT1 in tumors (carcinogenesis and cancer suppression). The present review reports the role of C1GALT1 in normal development and human diseases. Since the mechanism and regulation of C1GALT1 and O-glycosylation remain elusive, further studies are required to elucidate their effects on development and disease.

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.

C1GALT1 high expression is associated with poor survival of patients with pancreatic ductal adenocarcinoma and promotes cell invasiveness through integrin αv

Pancreatic adenocarcinoma (PDAC) is a leading cause of cancer-related death. Altered glycosylation contributes to tumor progression and chemoresistance in many cancers. C1GALT1 is the key enzyme controlling the elongation of GalNAc-type O-glycosylation. Here we showed that C1GALT1 was overexpressed in 85% (107/126) of PDAC tumors compared with adjacent non-tumor tissues. High expression of C1GALT1 was associated with poor disease-free and overall survival (n = 99). C1GALT1 knockdown using siRNA suppressed cell viability, migration, and invasion as well as increased gemcitabine sensitivity in PDAC cells. In contrast, C1GALT1 overexpression enhanced cell migration and invasion. In subcutaneous and pancreatic orthotopic injection models, C1GALT1 knockdown decreased tumor growth and metastasis of PDAC cells in NOD/SCID mice. Mechanistically, C1GALT1 knockdown dramatically suppressed cell-extracellular matrix (ECM) adhesion, which was associated with decreased phosphorylation of FAK at Y397/Y925 and changes in O-glycans on integrins including the β₁, α_v, and α₅ subunits. Using functional blocking antibodies, we identified integrin α_v as a critical factor in C1GALT1-mediated invasiveness of PDAC cells. In conclusion, this study not only reveals that C1GALT1 could be a potential therapeutic target for PDAC but also provides novel insights into the role of O-glycosylation in the α subunits of integrins.

Focal adhesion kinase: Insight into its roles and therapeutic potential in oesophageal cancer

Oesophageal cancer is associated with high morbidity and mortality rates because it is highly invasive and prone to recurrence and metastasis, with a five-year survival rate of <20%. Therefore, there is an urgent need for new methods aimed at improving therapeutic intervention. Several studies have shown that targeted therapy may be effective for the treatment of oesophageal cancer. Focal adhesion kinase (FAK), a non-receptor tyrosine kinase with kinase activity and scaffolding function, could be overexpressed in a variety of solid tumours, including oesophageal cancer. FAK participates in survival, proliferation, progression, adhesion, invasion, migration, epithelial-to-mesenchymal transition, angiogenesis, DNA damage repair, and other biological processes through multiple signalling pathways in cancer cells. It plays an important role in the occurrence and development of tumours and has been linked to the prognosis of oesophageal cancer. FAK has been suggested as a potential therapeutic target in oesophageal cancer; thus, the combination of FAK inhibitors with chemotherapy, radiotherapy, and immunotherapy is expected to prolong the survival of patients. This paper presents a brief overview of the structure of FAK and its potential role in oesophageal cancer, providing a rationale for the future application of FAK inhibitors in the treatment of the disease.

Curcumin potentiates laryngeal squamous carcinoma radiosensitivity via NF-ΚB inhibition by suppressing IKKγ expression

Context: Curcumin has shown efficacy in promoting radiosensitivity combined with radiotherapy. However, the role and mechanism of curcumin on radiosensitivity in laryngeal squamous cell cancer (LSCC) is largely unknown.Objective: The aim of our study is to explore the role of IKKγ-NF-κB signaling in curcumin enhancing LSCC cell radiosensitivity in vitro.Materials and methods: Curcumin and X-ray were used to induce cell DNA damage and apoptosis, or inhibit cell clone formation. IKKγ siRNA and plasmid were used to change IKKγ expression. The CCK8 assay was used to detect cell viability. Clone formation ability was analyzed using a clonogenic assay, cell apoptosis was examined using flow cytometry, an immunofluorescence assay was used to detect DNA damage, while mRNA and protein levels were assayed using real time PCR and western blotting, respectively.Results: Curcumin significantly enhanced irradiation-induced DNA damage and apoptosis, while weakening clone-forming abilities of LSCC cell line Hep2 and Hep2-max. Compared to Hep2 cells, Hep2-max cells are more sensitive to curcumin post-irradiation. Curcumin suppressed irradiation-induced NF-κB activation by suppressing IKKγ expression, but not IKKα and IKKβ. Overexpression of IKKγ decreased irradiation-induced DNA damage and apoptosis, while promoting clone-forming abilities of Hep2 and Hep2-max cells. IKKγ overexpression further increased expression of NF-κB downstream genes, Bcl-XL, Bcl-2, and cyclin D1. Conversely, IKKγ silencing enhanced irradiation-induced DNA damage and apoptosis, but promoted clone formation in Hep2 and Hep2-max cells. Additionally, IKKγ silencing inhibited expression of Bcl-XL, Bcl-2, and cyclin D1.Conclusions: Curcumin enhances LSCC radiosensitivity via NF-ΚB inhibition by suppressing IKKγ expression.

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.

A lectin-based glycomic approach identifies FUT8 as a driver of radioresistance in oesophageal squamous cell carcinoma

PURPOSE

Radio-resistance is recognized as a main factor in the failure of radiotherapy in oesophageal squamous cell carcinoma (ESCC). Aberrant cell surface glycosylation has been reported to correlate with radio-resistance in different kinds of tumours. However, glycomic alterations and the corresponding enzymes associated with ESCC radio-resistance have not yet been defined.

METHODS

Two radioresistant cell lines, EC109R and TE-1R, were established from parental ESCC cell lines EC109 and TE-1 by fractionated irradiation. A lectin microarray was used to screen for altered glycan patterns. RNA-sequencing (RNA-seq) was employed to identify differentially expressed glycosyltransferases. Cell Counting Kit-8, colony formation and flow cytometry assays were used to measure cell viability and radiosensitivity. Expression of glycosyltransferase in ESCC tissues was assessed by immunohistochemistry. In vivo radiosensitivity was analysed using a nude mouse xenograft model. Downstream effectors of the enzyme were verified using a lectin-based pull-down assay combined with mass spectrometry.

RESULTS

We found that EC109R and TE-1R cells were more resistant to irradiation than the parental EC109 and TE-1 cells. Using lectin microarrays combined with RNA sequencing, we found that α1, 6-fucosyltransferase (FUT8) was overexpressed in the radioresistant ESCC cell lines. Both gain- and loss-of-function studies confirmed that FUT8 regulates the sensitivity of ESCC cells to irradiation. Importantly, we found that high FUT8 expression was positively linked to radio-resistance and a poor prognosis in ESCC patients who received radiation therapy. Moreover, FUT8 inhibition suppressed the growth and formation of xenograft tumours in nude mice after irradiation. Using a lectin-based pull-down assay and mass spectrometry, we found that CD147 could be glycosylated by FUT8. As expected, inhibition of CD147 partly reversed FUT8-induced radio-resistance in ESCC cells.

CONCLUSIONS

Our results indicate that FUT8 functions as a driver of radio-resistance in ESCC by targeting CD147. Therefore, FUT8 may serve as a marker for predicting the response to radiation therapy in patients with ESCC.

Anti-C1GALT1 Autoantibody Is a Novel Prognostic Biomarker for Patients With Head and Neck Cancer

OBJECTIVES

The objective of this study is to determine the value of the anti- glycoprotein-N-acetylgalactosamine 3-beta-galactosyltransferase 1 (C1GALT1) autoantibody as a biomarker for distant metastasis and good response to immune checkpoint inhibitors in patients with head and neck squamous cell carcinoma (HNSCC).

METHODS

In this retrospective study with a median follow-up of 55.7 months, 186 HNSCC patients were enrolled between July 2013 and August 2014. Data were analyzed between April 2018 and November 2019. Titers of autoantibody against the C1GALT1 peptide were measured by ELISA. Student t test, Kaplan-Meier analysis, and univariate and multivariate Cox proportional hazard models were used to evaluate the association of anti-C1GALT1 autoantibody titer with clinicopathologic factors, survival, and response to immunotherapy.

RESULTS

Our results showed that high levels of the anti-C1GALT1 autoantibody is an independent marker for distant metastasis and poor disease-specific survivals in HNSCC patients. In 19 recurrent or metastatic (R/M) HNSCC patients who have received nivolumab or pembrolizumab, higher autoantibody titers are associated with a better treatment response.

CONCLUSION

We propose that the anti-C1GALT1 autoantibody can serve as a novel biomarker for distant metastasis in HNSCC patients. It is also useful in individualized medicine for R/M HNSCC patients who are considering immunotherapy.

LEVEL OF EVIDENCE

IV Laryngoscope, 131:E196-E202, 2021.

A Systematic Review on the Implications of O-linked Glycan Branching and Truncating Enzymes on Cancer Progression and Metastasis

Glycosylation is the most commonly occurring post-translational modifications, and is believed to modify over 50% of all proteins. The process of glycan modification is directed by different glycosyltransferases, depending on the cell in which it is expressed. These small carbohydrate molecules consist of multiple glycan families that facilitate cell-cell interactions, protein interactions, and downstream signaling. An alteration of several types of O-glycan core structures have been implicated in multiple cancers, largely due to differential glycosyltransferase expression or activity. Consequently, aberrant O-linked glycosylation has been extensively demonstrated to affect biological function and protein integrity that directly result in cancer growth and progression of several diseases. Herein, we provide a comprehensive review of several initiating enzymes involved in the synthesis of O-linked glycosylation that significantly contribute to a number of different cancers.

Curcumin Inhibits the Migration and Invasion of Non-Small-Cell Lung Cancer Cells Through Radiation-Induced Suppression of Epithelial-Mesenchymal Transition and Soluble E-Cadherin Expression

Radiotherapy has been reported to cause cancer metastasis. Thus, a new strategy for radiotherapy must be developed to avoid this side effect. A549 cells were exposed to radiation to induce an epithelial-mesenchymal transition (EMT) cell model. Real-time PCR and western blotting were used to detect mRNA and protein expression levels, and Transwell invasion and wound healing assays were used to detect cell migration and invasion. ELISA was used to detect soluble E-cadherin (sE-cad) secretion. siRNA was used to silence MMP9 expression. The results show that A549R cells exhibited an EMT phenotype with increased E-cadherin, N-cadherin, Snail, Slug, vimentin and Twist expression and decreased pan-keratin expression. sE-cad levels were increased in A549R cells and in the serum of NSCLC patients with distant metastasis. Exogenous sE-cad treatment and sE-cad overexpression promoted A549R and A549 cell migration and invasion. In contrast, blocking sE-cad attenuated A549 cell migration and invasion. Curcumin inhibited sE-cad expression and reversed EMT induced by radiation. Furthermore, curcumin suppressed sE-cad-enhanced A549 and A549R cell migration and invasion. Curcumin inhibited MMP9 expression, and silencing MMP9 suppressed sE-cad expression. Taken together, we found a nonclassic EMT phenomenon induced by radiation. Curcumin inhibits NSCLC migration and invasion by suppressing radiation-induced EMT and sE-cad expression by decreasing MMP9 expression.

Association between breast cancer cell migration and radiosensitivity in vitro

The aim of the present study was to examine the association between the migration of breast cancer cells in vitro and radiosensitivity by establishing a breast cancer cell model with different migratory capacities. Transwell chambers in a 24-well plate were used to separate MDA-MB-231 and ZR-7530 cells and to establish cell models with different migratory capacities. Subsequently, the radiosensitivity of the cell models was measured using a radiation clone formation assay. Furthermore, differential gene expression was determined using gene microarray analysis. The protein expression levels of the differentially expressed genes (DEGs) were assessed using western blot analysis. From each parental cell line, a pair of daughter cell lines were established in with differing migratory abilities. These daughter cell lines were named MDA-MB-231 UP-10 (231 UP-10), MDA-MB-231 Down-10 (231 Down-10), ZR-75-30 UP-10 (7530 UP-10) and ZR-75-30 Down-10 (7530 Down-10). Radiation clone formation assays revealed that the cell lines with increased migratory abilities (231 Down-10 and 7530 Down-10) demonstrated higher radio-resistance compared with the cell lines with decreased migratory abilities (231 UP-10 and 7530 UP-10). Gene microarrays identified numerous DEGs between the pairs of UP and Down cell lines. A focus was placed on genes associated with cell adhesion and it was identified that phosphorylated Fak and phosphorylated EGFR expression levels were increased in 231 Down-10 and 7530 Down-10 cells, compared with the 231 UP-10 and 7530 UP-10 cells. Other genes including ZO-1, FN1 and SOX9 expression were also increased in the 231 Down-10 and 7530 Down-10 cells compared with 231 UP-10 and 7530 UP-10 cells. Cell lines with increased migratory capacities may be more radio-resistant compared with cell lines with a decreased migratory capabilities. The mechanism may be associated with changes in the expression of cell adhesion molecules and epithelial-mesenchymal transition (EMT). Therapeutic strategies targeting cell adhesion or EMT may increase the radiation sensitivity of breast cancer cells, in addition to improving the effect of radiation therapy.