Intra- and Extra-Cellular Events Related to Altered Glycosylation of MUC1 Promote Chronic Inflammation, Tumor Progression, Invasion, and Metastasis

MUC1-EGFR crosstalk with IL-6 by activating NF-κB and MAPK pathways to regulate the stemness and paclitaxel-resistance of lung adenocarcinoma

BACKGROUND

The chemotherapy resistance often leads to chemotherapy failure. This study aims to explore the molecular mechanism by which MUC1 regulates paclitaxel resistance in lung adenocarcinoma (LUAD), providing scientific basis for future target selection.

METHODS

The bioinformatics method was used to analyse the mRNA and protein expression characteristics of MUC1 in LUAD. RT-qPCR and ELISA were used to detect the mRNA and protein expression, flow cytometry was used to detect CD133+ cells, and cell viability was detected by CCK-8 assay. The mRNA-seq was performed to analyse the changes in expression profile, GO and KEGG analysis were used to explore the potential biological functions.

RESULTS

MUC1 is highly expressed in LUAD patients and is associated with a higher tumour infiltration. In paclitaxel resistance LUAD cells (A549/TAX cells), the expression of MUC1, EGFR/p-EGFR and IL-6 were higher than that of A549 cells, the proportion of CD133+ cells was significantly increased, and the expression of cancer stem cell (CSCs) transcription factors (NANOG, OCT4 and SOX2) were significantly up-regulated. After knocking down MUC1 in A549/Tax cells, the activity of A549/Tax cells was significantly decreased. Correspondingly, the expression of EGFR, IL-6, OCT4, NANOG, and SOX2 were significantly down-regulated. The mRNA-seq showed that knocking down MUC1 affected the gene expression, DEGs mainly enriched in NF-κB and MAPK signalling pathway.

CONCLUSION

MUC1 was highly expressed in A549/TAX cells, and MUC1-EGFR crosstalk with IL-6 may be due to the activation of NF-κB and MAPK pathways, which promote the enrichment of CSCs and lead to paclitaxel resistance.

Integrative metagenomic, transcriptomic, and proteomic analysis reveal the microbiota-host interplay in early-stage lung adenocarcinoma among non-smokers

BACKGROUND

The incidence of early-stage lung adenocarcinoma (ES-LUAD) is steadily increasing among non-smokers. Previous research has identified dysbiosis in the gut microbiota of patients with lung cancer. However, the local microbial profile of non-smokers with ES-LUAD remains largely unknown. In this study, we systematically characterized the local microbial community and its associated features to enable early intervention.

METHODS

A prospective collection of ES-LUAD samples (46 cases) and their corresponding normal tissues adjacent to the tumor (41 cases), along with normal lung tissue samples adjacent to pulmonary bullae in patients with spontaneous pneumothorax (42 cases), were subjected to ultra-deep metagenomic sequencing, host transcriptomic sequencing, and proteomic sequencing. The obtained omics data were subjected to both individual and integrated analysis using Spearman correlation coefficients.

RESULTS

We concurrently detected the presence of bacteria, fungi, and viruses in the lung tissues. The microbial profile of ES-LUAD exhibited similarities to NAT but demonstrated significant differences from the healthy controls (HCs), characterized by an overall reduction in species diversity. Patients with ES-LUAD exhibited local microbial dysbiosis, suggesting the potential pathogenicity of certain microbial species. Through multi-omics correlations, intricate local crosstalk between the host and local microbial communities was observed. Additionally, we identified a significant positive correlation (rho > 0.6) between Methyloversatilis discipulorum and GOLM1 at both the transcriptional and protein levels using multi-omics data. This correlated axis may be associated with prognosis. Finally, a diagnostic model composed of six bacterial markers successfully achieved precise differentiation between patients with ES-LUAD and HCs.

CONCLUSIONS

Our study depicts the microbial spectrum in patients with ES-LUAD and provides evidence of alterations in lung microbiota and their interplay with the host, enhancing comprehension of the pathogenic mechanisms that underlie ES-LUAD. The specific model incorporating lung microbiota can serve as a potential diagnostic tool for distinguishing between ES-LUAD and HCs.

Protocol to prepare MUC1 glycopeptide vaccines and evaluate immunization effects in mice

The tumor-associated mucin MUC1 is overexpressed in almost all types of epithelial tumor tissues, making it an attractive target antigen for cancer immunotherapy. Here we present a protocol to prepare MUC1 glycopeptide vaccines and to evaluate immunization effects in mice. We describe steps for synthesizing glycopeptide antigen and conjugating it with carrier protein to make vaccine candidates. We then detail procedures for mice immunization, antibody response evaluation, and cellular immune response. For complete details on the use and execution of this protocol, please refer to Cai et al.1,2.

Tumor-associated carbohydrate antigens of MUC1 - Implication in cancer development

Glycosylation of cancerous epithelial MUC1 protein is specifically altered in comparison to that which is presented by healthy cells. One of such changes is appearing tumor-associated carbohydrate antigens (TACAs) which are rare in normal tissues and are highly correlated with poor clinical outcomes and cancer progression. This review summarizes and describes the role of Tn, T antigens, their sialylated forms as well as fucosylated Lewis epitopes in different aspects of tumor development, progression, and metastasis. Finally, applications of MUC1 glycan epitopes as potential targets for therapeutic strategy of cancers are notified. One of the novelties of this review is presentation of TACAs as inherently connected with MUC1 mucin.

Integrating TCGA and Single-Cell Sequencing Data for Hepatocellular Carcinoma: A Novel Glycosylation (GLY)/Tumor Microenvironment (TME) Classifier to Predict Prognosis and Immunotherapy Response

The major liver cancer subtype is hepatocellular carcinoma (HCC). Studies have indicated that a better prognosis is related to the presence of tumor-infiltrating lymphocytes (TILs) in HCC. However, the molecular pathways that drive immune cell variation in the tumor microenvironment (TME) remain poorly understood. Glycosylation (GLY)-related genes have a vital function in the pathogenesis of numerous tumors, including HCC. This study aimed to develop a GLY/TME classifier based on glycosylation-related gene scores and tumor microenvironment scores to provide a novel prognostic model to improve the prediction of clinical outcomes. The reliability of the signatures was assessed using receiver operating characteristic (ROC) and survival analyses and was verified with external datasets. Furthermore, the correlation between glycosylation-related genes and other cells in the immune environment, the immune signature of the GLY/TME classifier, and the efficacy of immunotherapy were also investigated. The GLY score low/TME score high subgroup showed a favorable prognosis and therapeutic response based on significant differences in immune-related molecules and cancer cell signaling mechanisms. We evaluated the prognostic role of the GLY/TME classifier that demonstrated overall prognostic significance for prognosis and therapeutic response before treatment, which may provide new options for creating the best possible therapeutic approaches for patients.

Changes in serum tumor markers in type 2 diabetes mellitus with microalbuminuria

Objectives

The objective of this study was to investigate changes in serum tumor markers in type 2 diabetes mellitus (T2DM) with microalbuminuria and analyze the relationship between tumor markers and microalbuminuria.

Methods

A total of 956 T2DM patients aged 40-70 years hospitalized in the Department of Endocrinology, Xinhua Hospital, China, affiliated with Shanghai Jiaotong University School of Medicine, were enrolled from January 2018 to December 2020. The sample comprised 313 T2DM patients with microalbuminuria and 643 T2DM patients with normal urinary microalbumin levels. After assessing the changes in serum tumor markers in T2DM with microalbuminuria, we analyzed the risk of microalbuminuria by the serum tumor marker category using multiple logistic regression analysis.

Results

Serum CEA, CA199, CA125, CA153, CA211, SCC, CA242, and CA50 levels were significantly higher in T2DM patients with microalbuminuria than in those without microalbuminuria, while serum AFP levels were lower in the microalbuminuria group (P < 0.05). Following adjustment of confounders, serum CEA, CA211, and SCC were independently associated with microalbuminuria in T2DM. An ROC curve was used to estimate the cutoff point of tumor markers for microalbuminuria. Taking the values under the cutoff points as a reference, values for CEA, CA211, and SCC above the cutoff points indicated a significantly high risk of microalbuminuria. The OR of increased CEA for microalbuminuria was 2.006 (95%CI 1.456-2.765), the OR of increased CA211 for microalbuminuria was 1.505 (95%CI 1.092-2.074), and the OR of increased SCC for microalbuminuria was 1.958 (95%CI 1.407-2.724).

Conclusion

Several serum tumor markers were related to microalbuminuria in T2DM. Serum tumor markers such as CEA, SCC, and CA211 may indicate early diabetic nephropathy, particularly when elevated in combination.

Tiliroside Combined with Anti-MUC1 Monoclonal Antibody as Promising Anti-Cancer Strategy in AGS Cancer Cells

Specific changes in mucin-type O-glycosylation are common for many cancers, including gastric ones. The most typical alterations include incomplete synthesis of glycan structures, enhanced expression of truncated O-glycans (Tn, T antigens and their sialylated forms), and overexpression of fucosylation. Such altered glycans influence many cellular activities promoting cancer development. Tiliroside is a glycosidic dietary flavonoid with pharmacological properties, including anti-cancer. In this study, we aim to assess the effect of the combined action of anti-MUC1 and tiliroside on some cancer-related factors in AGS gastric cancer cells. Cancer cells were treated with 40, 80, and 160 µM tiliroside, 5 µg/mL anti-MUC1, and flavonoid together with mAb. Real-Time PCR, ELISA, and Western blotting were applied to examine MUC1 expression, specific, tumor-associated antigens, enzymes taking part in their formation, Gal-3, Akt, and NF-κB. MUC1 expression was significantly reduced by mAb action. The combined action of anti-MUC1 and tiliroside was more effective in comparison with monotherapy in the case of C1GalT1, ST3GalT1, FUT4, Gal-3, NF-κB, Akt mRNAs, and Tn antigen, as well as sialyl T antigen expression. The results of our study indicate that applied combined therapy may be a promising anti-gastric cancer strategy.

Protein posttranslational modifications in health and diseases: Functions, regulatory mechanisms, and therapeutic implications

Protein posttranslational modifications (PTMs) refer to the breaking or generation of covalent bonds on the backbones or amino acid side chains of proteins and expand the diversity of proteins, which provides the basis for the emergence of organismal complexity. To date, more than 650 types of protein modifications, such as the most well-known phosphorylation, ubiquitination, glycosylation, methylation, SUMOylation, short-chain and long-chain acylation modifications, redox modifications, and irreversible modifications, have been described, and the inventory is still increasing. By changing the protein conformation, localization, activity, stability, charges, and interactions with other biomolecules, PTMs ultimately alter the phenotypes and biological processes of cells. The homeostasis of protein modifications is important to human health. Abnormal PTMs may cause changes in protein properties and loss of protein functions, which are closely related to the occurrence and development of various diseases. In this review, we systematically introduce the characteristics, regulatory mechanisms, and functions of various PTMs in health and diseases. In addition, the therapeutic prospects in various diseases by targeting PTMs and associated regulatory enzymes are also summarized. This work will deepen the understanding of protein modifications in health and diseases and promote the discovery of diagnostic and prognostic markers and drug targets for diseases.

Glycosylation in breast cancer progression and mammary development: Molecular connections and malignant transformations

INTRODUCTION

The cellular behavior in normal mammary gland development and the progression of breast cancer is like the relationship between an object and its mirror image: they may appear similar, but their essence is completely different. Breast cancer can be considered as temporal and spatial aberrations of normal development in mammary gland. Glycans have been shown to regulate key pathophysiological steps during mammary development and breast cancer progression, and the glycoproteins that play a key role in both processes can affect the normal differentiation and development of mammary cells, and even cause malignant transformation or accelerate tumorigenesis due to differences in their type and level of glycosylation.

KEY FINDINGS

In this review, we summarize the roles of glycan alterations in essential cellular behaviors during breast cancer progression and mammary development, and also highlight the importance of key glycan-binding proteins such as epidermal growth factor receptor, transforming growth factor β receptors and other proteins, which are pivotal in the modulation of cellular signaling in mammary gland. Our review takes an overall view of the molecular interplay, signal transduction and cellular behaviors in mammary gland development and breast cancer progression from a glycobiological perspective.

SIGNIFICANCE

This review will give a better understanding of the similarities and differences in glycosylation between mammary gland development and breast cancer progression, laying the foundation for elucidating the key molecular mechanisms of glycobiology underlying the malignant transformation of mammary cells.

Galectin-3 and Epithelial MUC1 Mucin-Interactions Supporting Cancer Development

Aberrant glycosylation of cell surface proteins is a very common feature of many cancers. One of the glycoproteins, which undergoes specific alterations in the glycosylation of tumor cells is epithelial MUC1 mucin, which is highly overexpressed in the malignant state. Such changes lead to the appearance of tumor associated carbohydrate antigens (TACAs) on MUC1, which are rarely seen in healthy cells. One of these structures is the Thomsen-Friedenreich disaccharide Galβ1-3GalNAc (T or TF antigen), which is typical for about 90% of cancers. It was revealed that increased expression of the T antigen has a big impact on promoting cancer progression and metastasis, among others, due to the interaction of this antigen with the β-galactose binding protein galectin-3 (Gal-3). In this review, we summarize current information about the interactions between the T antigen on MUC1 mucin and Gal-3, and their impact on cancer progression and metastasis.

Glycosylated proteins with abnormal glycosylation changes are potential biomarkers for early diagnosis of breast cancer

Conventional cancer management relies on tumor type and stage for diagnosis and treatment, which leads to recurrence and metastasis and death in young women. Early detection of proteins in the serum aids diagnosis, progression, and clinical outcomes, possibly improving survival rate of breast cancer patients. In this review, we provided an insight into the influence of aberrant glycosylation on breast cancer development and progression. Examined literatures revealed that mechanisms underlying glycosylation moieties alteration could enhance early detection, monitoring, and therapeutic efficacy in breast cancer patients. This would serve as a guide for the development of new serum biomarkers with higher sensitivity and specificity, providing possible serological biomarkers for breast cancer diagnosis, progression, and treatment.

p-Coumaric acid, Kaempferol, Astragalin and Tiliroside Influence the Expression of Glycoforms in AGS Gastric Cancer Cells

Abnormal glycosylation of cancer cells is considered a key factor of carcinogenesis related to growth, proliferation, migration and invasion of tumor cells. Many plant-based polyphenolic compounds reveal potential anti-cancer properties effecting cellular signaling systems. Herein, we assessed the effects of phenolic acid, p-coumaric acid and flavonoids such as kaempferol, astragalin or tiliroside on expression of selected cancer-related glycoforms and enzymes involved in their formation in AGS gastric cancer cells. The cells were treated with 80 and 160 µM of the compounds. RT-PCR, Western blotting and ELISA tests were performed to determine the influence of polyphenolics on analyzed factors. All the examined compounds inhibited the expression of MUC1, ST6GalNAcT2 and FUT4 mRNAs. C1GalT1, St3Gal-IV and FUT4 proteins as well as MUC1 domain, Tn and sialyl T antigen detected in cell lysates were also lowered. Both concentrations of kaempferol, astragalin and tiliroside also suppressed ppGalNAcT2 and C1GalT1 mRNAs. MUC1 cytoplasmic domain, sialyl Tn, T antigens in cell lysates and sialyl T in culture medium were inhibited only by kaempferol and tiliroside. Nuclear factor NF-κB mRNA expression decreased after treatment with both concentrations of kaempferol, astragalin and tiliroside. NF-κB protein expression was inhibited by kaempferol and tiliroside. The results indicate the rationality of application of examined polyphenolics as potential preventive agents against gastric cancer development.

Sushi-Repeat-Containing Protein X-Linked 2: A Potential Therapeutic Target for Inflammation and Cancer Therapy

Accumulating evidence has showed that sushi-repeat-containing protein X-linked 2 (SRPX2) is an abnormal expression in a variety of cancers and involved in cancer carcinogenesis, chemosensitivity, and prognosis, which mainly promote cancer cell metastasis, invasion, and migration by regulating the uPAR/integrins/FAK signaling pathway, epithelial-mesenchymal transition (EMT), angiogenesis, and glycosylation. Inflammation has been regarded as a key role in regulating cancer initiation, progression, EMT, and therapeutics. Furthermore, SRPX2 exhibited excellent antifibrosis effect via the TGFβR1/SMAD3/SRPX2/AP1/SMAD7 signaling pathway. Therefore, this review provides compelling evidence that SRPX2 might be a therapeutic target for inflammation and cancer-related inflammation for future cancer therapeutics.

Altered glycosylation in pancreatic cancer and beyond

Pancreatic ductal adenocarcinoma (PDA) is one of the deadliest cancers and is projected to soon be the second leading cause of cancer death. Median survival of PDA patients is 6-10 mo, with the majority of diagnoses occurring at later, metastatic stages that are refractory to treatment and accompanied by worsening prognoses. Glycosylation is one of the most common types of post-translational modifications. The complex landscape of glycosylation produces an extensive repertoire of glycan moieties, glycoproteins, and glycolipids, thus adding a dynamic and tunable level of intra- and intercellular signaling regulation. Aberrant glycosylation is a feature of cancer progression and influences a broad range of signaling pathways to promote disease onset and progression. However, despite being so common, the functional consequences of altered glycosylation and their potential as therapeutic targets remain poorly understood and vastly understudied in the context of PDA. In this review, the functionality of glycans as they contribute to hallmarks of PDA are highlighted as active regulators of disease onset, tumor progression, metastatic capability, therapeutic resistance, and remodeling of the tumor immune microenvironment. A deeper understanding of the functional consequences of altered glycosylation will facilitate future hypothesis-driven studies and identify novel therapeutic strategies in PDA.

Biology, Significance and Immune Signaling of Mucin 1 in Hepatocellular Carcinoma

Mucin 1 (MUC 1) is a highly glycosylated tumor-associated antigen (TAA) overexpressed in hepatocellular carcinoma (HCC). This protein plays a critical role in various immune-mediated signaling pathways at its transcriptional and post-transcriptional levels, leading to immune evasion and metastasis in HCC. HCC cells maintain an immune-suppressive environment with the help of immunesuppressive tumor-associated antigens, resulting in a metastatic spread of the disease. The development of intense immunotherapeutic strategies to target tumor-associated antigen is critical to overcoming the progression of HCC. MUC 1 remains the most recognized tumor-associated antigen since its discovery over 30 years ago. A few promising immunotherapies targeting MUC 1 are currently under clinical trials, including CAR-T and CAR-pNK-mediated therapies. This review highlights the biosynthesis, significance, and clinical implication of MUC 1 as an immune target in HCC.

Nanoparticle conjugated with aptamer anti-MUC1/Y for inflammatory arthritis

Aptamers may form well-defined three-dimensional structures binding with high affinity and stability to a specific receptor. The aptamer anti-MUC1 isoform Y is one the most used due the affinity to MUC1, which is overexpressed in several types of cancer and inflammation process. In this study we have developed, characterized, in vitro as in vivo evaluated a nanoaptamer (anti-MUC1/Y) as a nanoagent for rheumatoid arthritis treatment. The results showed that a nanoaptamer with a size range of 241 nm was produced. The entrapment efficacy was 90% with a biodistribution showing a high hepatic uptake (>98%). The results in vivo showed a potent effect in arthritis experimental model, especially in low doses. The results corroborate the applicability of this nanosystem for RA treatment.

Identification of Cell Surface Molecules That Determine the Macrophage Activation Threshold Associated With an Early Stage of Malignant Transformation

The ability of immune cells to sense changes associated with malignant transformation as early as possible is likely to be important for the successful outcome of cancer immunosurveillance. In this process, the immune system faces a trade-off between elimination of cells harboring premalignant or malignant changes, and autoimmune pathologies. We hypothesized that the immune system has therefore evolved a threshold for the stage of transformation from normal to fully malignant cells that first provides a threat (danger) signal requiring a response. We co-cultured human macrophages with a unique set of genetically related human cell lines that recapitulate successive stages in breast cancer development: MCF10A (immortalized, normal); MCFNeoT (benign hyperplasia); MCFT1 (atypical hyperplasia); MCFCA1 (invasive cancer). Using cytokines-based assays, we found that macrophages were inert towards MCF10A and MCFNeoT but were strongly activated by MCFT1 and MCFCA1 to produce inflammatory cytokines, placing the threshold for recognition between two premalignant stages, the earlier stage MCFNeoT and the more advanced MCFT1. The cytokine activation threshold paralleled the threshold for enhanced phagocytosis. Using proteomic and transcriptomic approaches, we identified surface molecules, some of which are well-known tumor-associated antigens, that were absent or expressed at low levels in MCF10A and MCFNeoT but turned on or over-expressed in MCFT1 and MCFCA1. Adding antibodies specific for two of these molecules, Annexin-A1 and CEACAM1, inhibited macrophage activation, supporting their role as cancer "danger signals" recognized by macrophages.

Procaspase-1 patrolled to the nucleus of proatherogenic lipid LPC-activated human aortic endothelial cells induces ROS promoter CYP1B1 and strong inflammation

To determine the roles of nuclear localization of pro-caspase-1 in human aortic endothelial cells (HAECs) activated by proatherogenic lipid lysophosphatidylcholine (LPC), we examined cytosolic and nuclear localization of pro-caspase-1, identified nuclear export signal (NES) in pro-caspase-1 and sequenced RNAs. We made the following findings: 1) LPC increases nuclear localization of procaspase-1 in HAECs. 2) Nuclear pro-caspase-1 exports back to the cytosol, which is facilitated by a leptomycin B-inhibited mechanism. 3) Increased nuclear localization of pro-caspase-1 by a new NES peptide inhibitor upregulates inflammatory genes in oxidative stress and Th17 pathways; and SUMO activator N106 enhances nuclear localization of pro-caspase-1 and caspase-1 activation (p20) in the nucleus. 4) LPC plus caspase-1 enzymatic inhibitor upregulates inflammatory genes with hypercytokinemia/hyperchemokinemia and interferon pathways, suggesting a novel capsase-1 enzyme-independent inflammatory mechanism. 5) LPC in combination with NES inhibitor and caspase-1 inhibitor upregulate inflammatory gene expression that regulate Th17 activation, endotheli-1 signaling, p38-, and ERK- MAPK pathways. To examine two hallmarks of endothelial activation such as secretomes and membrane protein signaling, LPC plus NES inhibitor upregulate 57 canonical secretomic genes and 76 exosome secretomic genes, respectively, promoting four pathways including Th17, IL-17 promoted cytokines, interferon signaling and cholesterol biosynthesis. LPC with NES inhibitor also promote inflammation via upregulating ROS promoter CYP1B1 and 11 clusters of differentiation (CD) membrane protein pathways. Mechanistically, all the LPC plus NES inhibitor-induced genes are significantly downregulated in CYP1B1-deficient microarray, suggesting that nuclear caspase-1-induced CYP1B1 promotes strong inflammation. These transcriptomic results provide novel insights on the roles of nuclear caspase-1 in sensing DAMPs, inducing ROS promoter CYP1B1 and in regulating a large number of genes that mediate HAEC activation and inflammation. These findings will lead to future development of novel therapeutics for cardiovascular diseases (CVD), inflammations, infections, transplantation, autoimmune disease and cancers. (total words: 284).

Anti-Cancer Potential of Afzelin towards AGS Gastric Cancer Cells

Afzelin demonstrates anti-inflammatory and anti-cancer properties. Our purpose was to assess its influence on apoptosis, Bax, caspases, MUC1, cancer-related carbohydrate antigens, enzymes participating in their formation, and galectin-3 in AGS gastric cancer cells. A total of 60 and 120 μM afzelin was used in all experiments. Flow cytometry was applied to determine apoptotic response. Western blotting and RT PCR were used to detect the expression of mentioned factors. Flavonoid at higher concentration revealed slight apoptotic respond. Bax, caspase-3, -8, -9 increased upon afzelin action. Stimulatory effect of the flavonoid on MUC1 cytoplasmic tail and extracellular domain in cell lysates and on MUC1 gene was revealed. MUC1 release into the culture medium was inhibited by the flavonoid. The 60 μM afzelin dose stimulated GalNAcTL5 protein expression and inhibited C1GalT1. ST6GalNAcT mRNA was inhibited by both flavonoid doses. ST3GalT was inhibited by 120 μM afzelin on protein and mRNA level. Lewisa/b protein was reduced by both afzelin concentrations. FUT3 and FUT4 mRNA was inhibited by 120 μM dose of afzelin. Galectin-3 protein increased in cell lysates and decreased in culture supernatant by 60 and 120 μM flavonoid. Galectin-3 gene expression was stimulated by two used concentrations of afzelin in comparison to control. We conclude that afzelin can be considered as the potential anti-cancer agent, supporting conventional cancer treatment.

MUC1 is an oncoprotein with a significant role in apoptosis (Review)

Mucin 1 (MUC1) is a membrane-bound, highly glycosylated protein that is overexpressed in all stages of malignant transformation. Overexpression of MUC1 together with loss of polarization and hypoglycosylation are associated with resistance to apoptosis, which is the process that results in efficient removal of damaged cells. Inhibition of the apoptotic process is responsible for tumor development, tumor progression and drug resistance. MUC1 is considered as an oncogenic molecule that is involved in various signaling pathways responsible for the regulation of apoptosis. Based on this, the aim of the present study was to discuss the involvement of MUC1 in the divergent mechanisms regulating programmed cell death.

Anti-cancer effect of combined action of anti-MUC1 and rosmarinic acid in AGS gastric cancer cells

MUC1 seems to be promising target in cancer cells due to its abundant and specifically altered expression as well as differential distribution pattern relative to normal tissues. Rosmarinic acid (RA) is a natural, polyphenolic compound with pharmacological activities, including anti-cancer. Herein, we aim to explore the effect of combined action of anti-MUC1 and RA on selected cancer-related factors in AGS gastric cancer cells. Cancer cells were treated with 100, 200 μM rosmarinic acid, 5 μg/ml anti-MUC1 and acid together with antibody. Western blotting, ELISA and RT-PCR were used to assess the expression of MUC1, selected sugar antigens, enzymes participating in protein glycosylation, Gal-3, p53, pro- and anti-apoptotic factors, and caspases-3,-8,-9 in cancer cells. MUC1 mRNA was significantly suppressed by combined action of anti-MUC1 and RA. Such treatment markedly inhibited expression of cancer-related Tn, T, sialyl Tn, sialyl T, and fucosylated sugar antigens as well as mRNA expression of enzymes participating in their formation: ppGalNAcT2, C1GalT1, ST6GalNAcT2, ST3GalT1 and FUT4. C1GalT1 was suppressed also on protein level. Gal-3, factor likely participating in metastasis, was significantly suppressed on mRNA level by RA administrated with anti-MUC1. Pro-apoptotic Bax protein and Bad mRNA were significantly induced, and anti-apoptotic Bcl-2 mRNA expression was inhibited by such treatment. Combined action of mAb and RA markedly increased caspase-9 mRNA expression. Results of the study indicate that combined action of anti-MUC1 and RA is more effective than monotherapy in relation to examined cancer related factors. Such treatment can be considered as new, promising strategy in gastric cancer therapy.

Combined Action of Anti-MUC1 Monoclonal Antibody and Pyrazole-Platinum(II) Complexes Reveals Higher Effectiveness towards Apoptotic Response in Comparison with Monotherapy in AGS Gastric Cancer Cells

MUC1 mucin is a transmembrane glycoprotein aberrantly overexpressed and underglycosylated in most epithelium origin cancers. Combining chemotherapeutics with monoclonal antibodies toward cancer-related antigens is one of the new strategies in cancer therapies. In this study, we assessed the effectiveness of 10 μM cisplatin (cisPt), two pyrazole-platinum(II) complexes (PtPz4 and PtPz6), and 5 μg/mL anti-MUC1 used as monotherapy, as well as cisplatin and its derivatives combined with mAb on apoptotic response and specific cancer-related sugar antigens in AGS gastric cancer cells. Flow cytometry, RT-PCR, Western blotting, and ELISA tests were applied to determine the influence of examined compounds on analyzed factors. PtPz6 combined with anti-MUC1 revealed the strongest apoptotic response compared to control and monotherapy. The combined action of both cisPt derivatives and anti-MUC1 was more effective than monotherapy in relation to Bad, Bcl-xL, Bcl-2, caspase-9, caspase-3, as well as pro- and cleaved caspase-3 protein, and T, sialyl Tn sugar antigens in cell lysates, and Tn, T, sialyl Tn, sialyl T antigens in culture medium. Additionally, PtPz4 administrated with mAb was revealed to be more potent than used alone with regard to Bax protein and Bid expression, and PtPz6 used in complex with anti-MUC1 revealed more efficient action towards Akt and sialyl T antigen expression. These data indicate the rationality of the potential application of combined treatment of anti-MUC1 and cisPt derivatives in gastric cancer therapy.

MUC1: Structure, Function, and Clinic Application in Epithelial Cancers

The transmembrane glycoprotein mucin 1 (MUC1) is a mucin family member that has different functions in normal and cancer cells. Owing to its structural and biochemical properties, MUC1 can act as a lubricant, moisturizer, and physical barrier in normal cells. However, in cancer cells, MUC1 often undergoes aberrant glycosylation and overexpression. It is involved in cancer invasion, metastasis, angiogenesis, and apoptosis by virtue of its participation in intracellular signaling processes and the regulation of related biomolecules. This review introduces the biological structure and different roles of MUC1 in normal and cancer cells and the regulatory mechanisms governing these roles. It also evaluates current research progress and the clinical applications of MUC1 in cancer therapy based on its characteristics.

Nonspecific nuclear uptake of anti-MUC1 aptamers by dead cells: the role of cell viability monitoring in aptamer targeting of membrane-bound protein cancer biomarkers

Most aptamers targeting cell-expressed antigens are intended for in vivo application, however, these sequences are commonly generated in vitro against synthetic oligopeptide epitopes or recombinant proteins. As these in vitro analogues frequently do not mimic the in vivo target within an endogenous environment, the evolved aptamers are often prone to nonspecific binding. The presence of dead cells and cellular debris further complicate aptamer targeting, due to their high nonspecific affinities to single-stranded DNA. Despite these known limitations, assessment of cell viability and/or the removal of dead cells is rarely applied as part of the methodology during in vivo testing of aptamer binding. Furthermore, the extent and route(s) by which dead cells uptake existing aptamers remains to be determined in the literature. For this purpose, the previously reported aptamer sequences 5TR1, 5TR4, 5TRG2 and S22 - enriched against the MUC1 tumour marker of the mucin glycoprotein family - were used as model sequences to evaluate the influence of cell viability and the presence of nontarget cell-expressed protein on aptamer binding to the MUC1 expressing human cancer cell lines MCF-7, Hs578T, SW480, and SW620. From fluorescence microscopy analysis, all tested aptamers demonstrated extensive nonspecific uptake within the nuclei of dead cells with compromised membrane integrities. Using fluorescent-activated cell sorting (FACS), the inclusion of excess double-stranded DNA as a blocking agent showed no effect on nonspecific aptamer uptake by dead cells. Further nonspecific binding to cell-membrane bound and intracellular protein was evident for each aptamer sequence, as assessed by southwestern blotting and FACS. These factors likely contributed to the ∼120-fold greater binding response of the 5TR1 aptamer to dead MCF-7 cells over equivalent live cell populations. The identification of dead cells and cellular debris using viability stains and the subsequent exclusion of these cells from FACS analysis was identified as an essential requirement for the evaluation of aptamer binding specificity to live cell populations of the cancer cell lines MCF-7, Hs578T and SW480. The research findings stress the importance of dead cell uptake and more comprehensive cell viability screening to validate novel aptamer sequences for diagnostic and therapeutic application.

Dendritic Cell-Based Immunotherapy in Lung Cancer

Lung cancer remains the leading cause of cancer-related death worldwide. The advent of immune checkpoint inhibitors has led to a paradigm shift in the treatment of metastatic non-small cell and small cell lung cancer. However, despite prolonged overall survival, only a minority of the patients derive clinical benefit from these treatments suggesting that the full anti-tumoral potential of the immune system is not being harnessed yet. One way to overcome this problem is to combine immune checkpoint blockade with different strategies aimed at inducing or restoring cellular immunity in a tumor-specific, robust, and durable way. Owing to their unique capacity to initiate and regulate T cell responses, dendritic cells have been extensively explored as tools for immunotherapy in many tumors, including lung cancer. In this review, we provide an update on the nearly twenty years of experience with dendritic cell-based immunotherapy in lung cancer. We summarize the main results from the early phase trials and give an overview of the future perspectives within this field.

Altered Expression of the Epithelial Mucin MUC1 Accompanies Endoscopic Recurrence of Postoperative Crohn's Disease

BACKGROUND

MUC1-glycoprotein is expressed at low levels and in fully glycosylated form on epithelial cells. Inflammation causes MUC1 overexpression and hypoglycosylation. We hypothesized that overexpression of hypoglycosylated MUC1 would be found in postoperative Crohn's disease (CD) recurrence and could be considered an additional biomarker of recurrence severity.

METHODS

We examined archived neo-terminal ileum biopsies from patients with prior ileocecal resection who had postoperative endoscopic assessment of CD recurrence and given a Rutgeerts ileal recurrence score. Consecutive tissue sections were stained using 2 different anti-MUC1 antibodies, HMPV that recognizes all forms of MUC1 and 4H5 that recognizes only inflammation-associated hypoglycosylated MUC1.

RESULTS

A total of 71 postoperative CD patients were evaluated. There was significant increase in MUC1 expression of both glycosylated/normal (P<0.0001) and hypoglycosylated/abnormal (P<0.0001) forms in patients with severe endoscopic CD recurrence (i3+i4), ileal score i2, compared with patients in endoscopic remission (i0+i1). Results were similar regardless of anti-TNF-α use. Although MUC1 expression and Rutgeerts scores were in agreement when characterizing the majority of cases, there were a few exceptions where MUC1 expression was characteristic of more severe recurrence than implied by Rutgeerts score.

CONCLUSIONS

MUC1 is overexpressed and hypoglycosylated in neo-terminal ileum tissue of patients with postoperative CD recurrence. Increased levels are associated with more severe endoscopic recurrence scores, and this is not influenced by anti-TNF-α use. Discrepancies found between Rutgeerts scores and MUC1 expression suggest that addition of MUC1 as a biomarker of severity of postoperative CD recurrence may improve categorization of recurrence status and consequently treatment decisions.

MUC Glycoproteins: Potential Biomarkers and Molecular Targets for Cancer Therapy

MUC proteins have great significance as prognostic and diagnostic markers as well as a potential target for therapeutic interventions in most cancers of glandular epithelial origin. These are high molecular weight glycosylated proteins located in the epithelial lining of several tissues and ducts. Mucins belong to a heterogeneous group of large O-glycoproteins that can be either secreted or membrane-bound. Glycosylation, a post-translational modification affects the biophysical, functional and biochemical properties and provides structural complexity for these proteins. Aberrant expression and glycosylation of mucins contribute to tumour survival and proliferation in many cancers, which in turn activates numerous signalling pathways such as NF-kB, ERα, HIF, MAPK, p53, c-Src, Wnt and JAK-STAT, etc. This subsequently induces cancer cell growth, proliferation and metastasis. The present review mainly demonstrates the functional aspects of MUC glycoproteins along with its unique signalling mechanism and role of aberrant glycosylation in cancer progression and therapeutics. The importance of MUC proteins and its subtypes in a wide spectrum of cancers including but not limited to breast cancer, colorectal cancer, endometrial and cervical cancer, lung cancer, primary liver cancer, pancreatic cancer, prostate cancer and ovarian cancer has been exemplified with significance in targeting the same. Several patents associated with the MUC proteins in the field of cancer therapy are also emphasized in the current review.

Luteolin alters MUC1 extracellular domain, sT antigen, ADAM-17, IL-8, IL-10 and NF-κB expression in Helicobacter pylori-infected gastric cancer CRL-1739 cells: A preliminary study

Luteolin is a natural flavonoid possessing certain beneficial pharmacological properties, including anti-oxidant, anti-inflammatory, anti-microbial and anti-cancer properties. The majority of types of gastric cancer with chronic gastritis are caused by infection with Helicobacter pylori (H. pylori). The present study evaluated the effect of luteolin on a number of selected factors that are potentially involved in gastric cancer development. The study was performed using gastric cancer CRL-1739 cells treated with 30 µM luteolin and H. pylori alone or combined. ELISA and reverse transcription PCR were used to assess the expression levels of MUC1, GalNAcα-R (Tn antigen) and NeuAcα2-3Galβ1-3GalNAc-R (sT antigen), ADAM-17, IL-8, IL-10 and NF-κB. H. pylori and luteolin independently and in combination significantly reduced the expression levels of the extracellular domain of MUC1 in gastric cancer cells compared with the untreated control cells. ADAM-17 expression was reduced by treatment with the pathogen and luteolin. Additionally, both factors reduced sT antigen expression. Treatment with 30 ≤M luteolin significantly induced IL-8 expression at the mRNA and protein level, and the mRNA expression levels of IL-10 and NF-κB compared with the control. Both H. pylori and luteolin induced IL-8 protein expression. The present preliminary results suggest that luteolin may be used to treat patients with gastric cancer.

Inflammation-Induced Abnormal Expression of Self-molecules on Epithelial Cells: Targets for Tumor Immunoprevention

Tumor-associated antigens (TAA) are self-molecules abnormally expressed on tumor cells, which elicit humoral and cellular immunity and are targets of immunosurveillance. Immunity to TAAs is found in some healthy individuals with no history of cancer and correlates positively with a history of acute inflammatory and infectious events and cancer risk reduction. This suggests a potential role in cancer immunosurveillance for the immune memory elicited against disease-associated antigens (DAA) expressed on infected and inflamed tissues that are later recognized on tumors as TAAs. To understand probable sources for DAA generation, we investigated in vitro the role of inflammation that accompanies both infection and carcinogenesis. After exposure of normal primary breast epithelial cells to proinflammatory cytokines IL1β, IL6, and TNFα, or macrophages producing these cytokines, we saw transient overexpression of well-known TAAs, carcinoembryonic antigen and Her-2/neu, and overexpression and hypoglycosylation of MUC1. We documented inflammation-induced changes in the global cellular proteome by 2D difference gel electrophoresis combined with mass spectrometry and identified seven new DAAs. Through gene profiling, we showed that the cytokine treatment activated NF-κB and transcription of the identified DAAs. We tested three in vitro-identified DAAs, Serpin B1, S100A9, and SOD2, and found them overexpressed in premalignant and malignant breast tissues as well as in inflammatory conditions of the colon, stomach, and liver. This new category of TAAs, which are also DAAs, represent a potentially large number of predictable, shared, immunogenic, and safe antigens to use in preventative cancer vaccines and as targets for cancer therapies.

Evolution of Sequence-Diverse Disordered Regions in a Protein Family: Order within the Chaos

Approaches for studying the evolution of globular proteins are now well established yet are unsuitable for disordered sequences. Our understanding of the evolution of proteins containing disordered regions therefore lags that of globular proteins, limiting our capacity to estimate their evolutionary history, classify paralogs, and identify potential sequence–function relationships. Here, we overcome these limitations by using new analytical approaches that project representations of sequence space to dissect the evolution of proteins with both ordered and disordered regions, and the correlated changes between these. We use the fasciclin-like arabinogalactan proteins (FLAs) as a model family, since they contain a variable number of globular fasciclin domains as well as several distinct types of disordered regions: proline (Pro)-rich arabinogalactan (AG) regions and longer Pro-depleted regions.

Sequence space projections of fasciclin domains from 2019 FLAs from 78 species identified distinct clusters corresponding to different types of fasciclin domains. Clusters can be similarly identified in the seemingly random Pro-rich AG and Pro-depleted disordered regions. Sequence features of the globular and disordered regions clearly correlate with one another, implying coevolution of these distinct regions, as well as with the N-linked and O-linked glycosylation motifs. We reconstruct the overall evolutionary history of the FLAs, annotated with the changing domain architectures, glycosylation motifs, number and length of AG regions, and disordered region sequence features. Mapping these features onto the functionally characterized FLAs therefore enables their sequence–function relationships to be interrogated. These findings will inform research on the abundant disordered regions in protein families from all kingdoms of life.

Tumor-associated O-glycans of MUC1: Carriers of the glyco-code and targets for cancer vaccine design

The transformation from normal to malignant phenotype in human cancers is associated with aberrant cell-surface glycosylation. It has frequently been reported that MUC1, the heavily glycosylated cell-surface mucin, is altered in both, expression and glycosylation pattern, in human carcinomas of the epithelium. The presence of incomplete or truncated glycan structures, often capped by sialic acid, commonly known as tumor-associated carbohydrate antigens (TACAs), play a key role in tumor initiation, progression, and metastasis. Accumulating evidence suggests that expression of TACAs is associated with tumor escape from immune defenses. In this report, we will give an overview of the oncogenic functions of MUC1 that are exerted through TACA interactions with endogenous carbohydrate-binding proteins (lectins). These interactions often lead to creation of a pro-tumor microenvironment, favoring tumor progression and metastasis, and tumor evasion. In addition, we will describe current efforts in the design of cancer vaccines with special emphasis on synthetic MUC1 glycopeptide vaccines. Analysis of the key factors that govern structure-based design of immunogenic MUC1 glycopeptide epitopes are described. The role of TACA type, position, and density on observed humoral and cellular immune responses is evaluated.

Cross-talk between Colon Cells and Macrophages Increases ST6GALNAC1 and MUC1-sTn Expression in Ulcerative Colitis and Colitis-Associated Colon Cancer

Patients with ulcerative colitis have an increased risk of developing colitis-associated colon cancer (CACC). Changes in glycosylation of the oncoprotein MUC1 commonly occur in chronic inflammation, including ulcerative colitis, and this abnormally glycosylated MUC1 promotes cancer development and progression. It is not known what causes changes in glycosylation of MUC1. Gene expression profiling of myeloid cells in inflamed and malignant colon tissues showed increased expression levels of inflammatory macrophage-associated cytokines compared with normal tissues. We analyzed the involvement of macrophage-associated cytokines in the induction of aberrant MUC1 glycoforms. A coculture system was used to examine the effects of M1 and M2 macrophages on glycosylation-related enzymes in colon cancer cells. M2-like macrophages induced the expression of the glycosyltransferase ST6GALNAC1, an enzyme that adds sialic acid to O-linked GalNAc residues, promoting the formation of tumor-associated sialyl-Tn (sTn) O-glycans. Immunostaining of ulcerative colitis and CACC tissue samples confirmed the elevated number of M2-like macrophages as well as high expression of ST6GALNAC1 and the altered MUC1-sTn glycoform on colon cells. Cytokine arrays and blocking antibody experiments indicated that the macrophage-dependent ST6GALNAC1 activation was mediated by IL13 and CCL17. We demonstrated that IL13 promoted phosphorylation of STAT6 to activate transcription of ST6GALNAC1. A computational model of signaling pathways was assembled and used to test IL13 inhibition as a possible therapy. Our findings revealed a novel cellular cross-talk between colon cells and macrophages within the inflamed and malignant colon that contributes to the pathogenesis of ulcerative colitis and CACC.See related Spotlight on p. 160.

miR-217 inhibits the migration and invasion of HeLa cells through modulating MAPK1

MicroRNA (miR)-217 serves a pivotal role in the progression of colorectal cancer, renal cell carcinoma and glioma, however, the role of miR-217 in cervical cancer (CC) remains unclear. In the present study, the mechanism of miR-217 in cervical cancer was explored. The mRNA expression of miR-217 and mitogen-activated protein kinase 1 (MAPK1) were assessed using reverse transcription-quantitative polymerase chain reaction analysis. Cell Counting-Kit 8, wound-healing and Transwell assays were performed to detect cell viability, migration and invasion, respectively. Apoptosis and cell cycle were determined by flow cytometry. TargetScan 7.2 and dual-luciferase reporter assays were respectively used to determine miR-217 target genes and their binding capacities. The protein expression levels of MAPK1, phosphorylated (p)-extracellular signal-regulated kinase 1/2 (ERK1/2)/ERK1/2, Bcl-2, Bax and cleaved caspase-3 were quantified by western blotting. It was found that miR-217 was downregulated in patients with CC and in CC cells. The viability, migration and invasion of cells were suppressed by a miR-217 mimic. It was also found that apoptosis was increased and cell cycle was inhibited by the miR-217mimic, which was supported by changes in Bcl-2, Bax and cleaved caspase-3. MAPK1 was upregulated in patients with CC and was a target gene of miR-217. MAPK1 reversed the inhibition of miR-217 on cell viability, migration, invasion and apoptosis. The protein levels of MAPK1 and p-ERK1/2, which were higher in the mimic MAPK1 group than those in the control or mimic groups, were ameliorated by PD98059. The results of the present study demonstrated that miR-217 had an anti-CC effect and may be effectively used in the treatment of CC.

Glycosylation in health and disease

The glycome describes the complete repertoire of glycoconjugates composed of carbohydrate chains, or glycans, that are covalently linked to lipid or protein molecules. Glycoconjugates are formed through a process called glycosylation and can differ in their glycan sequences, the connections between them and their length. Glycoconjugate synthesis is a dynamic process that depends on the local milieu of enzymes, sugar precursors and organelle structures as well as the cell types involved and cellular signals. Studies of rare genetic disorders that affect glycosylation first highlighted the biological importance of the glycome, and technological advances have improved our understanding of its heterogeneity and complexity. Researchers can now routinely assess how the secreted and cell-surface glycomes reflect overall cellular status in health and disease. In fact, changes in glycosylation can modulate inflammatory responses, enable viral immune escape, promote cancer cell metastasis or regulate apoptosis; the composition of the glycome also affects kidney function in health and disease. New insights into the structure and function of the glycome can now be applied to therapy development and could improve our ability to fine-tune immunological responses and inflammation, optimize the performance of therapeutic antibodies and boost immune responses to cancer. These examples illustrate the potential of the emerging field of 'glycomedicine'.

Rosmarinic acid influences collagen, MMPs, TIMPs, glycosylation and MUC1 in CRL-1739 gastric cancer cell line

Rosmarinic acid (RA) is a natural phenylpropanoid with numerous pharmacological activities. Because of limited studies of the effects of RA action in gastric cancer cells we examined how 100 and 200 μM acid influences MMPs, TIMPs, collagen, MUC1 and specific sugar antigens in gastric adenocarcinoma CRL-1739 cells. We revealed inhibitory effect of RA on MMP-9 activity what was correlated with increased collagen type I expression, main ECM substrate degraded by MMPs. Tissue inhibitor of MMPs, TIMP-1 but not TIMP-2 was significantly decreased on the protein level and increased on mRNA level by RA action what can suggest TIMP-1 independent inhibitory action of an acid on MMP-9 activity. Glycosylation of gastric cancer proteins was also effected by RA. ELISA tests revealed inhibitory effect of an acid on Tn antigen in cell lysates and culture supernatant and on T antigen in cell lysates. RA inhibited also sialylated Tn antigen in protein of culture supernatant and sialyl T in cell lysates. Extracellular domain of MUC1 mucin, main carrier of Tn and T antigens was significantly inhibited by higher dose of RA. The data suggest potential usefulness of RA as a complementary agent supporting chemotherapy in cancer treatment.

Sortase A: A Model for Transpeptidation and Its Biological Applications

Molecular biologists and chemists alike have long sought to modify proteins with substituents that cannot be installed by standard or even advanced genetic approaches. We here describe the use of transpeptidases to achieve these goals. Living systems encode a variety of transpeptidases and peptide ligases that allow for the enzyme-catalyzed formation of peptide bonds, and protein engineers have used directed evolution to enhance these enzymes for biological applications. We focus primarily on the transpeptidase sortase A, which has become popular over the past few years for its ability to perform a remarkably wide variety of protein modifications, both in vitro and in living cells.

Serum carbohydrate antigen 153 and renal function in patients with type 2 diabetes mellitus

OBJECTIVE

The aim of our study was to investigate the correlation between serum carbohydrate antigen 153 (CA153) and renal function in patients with type 2 diabetes mellitus (T2DM).

METHODS

A total of 184 patients with T2DM were included, and renal function was assessed by the modification of diet in renal disease (MDRD) formula adjusted coefficient of the Chinese people.

RESULTS

Serum CA153 concentrations were positively correlated with blood glucose (BG) and glycated hemoglobin (HbA1c) (r = .204, P = .005; r = .165, P = .025) in patients with T2DM. There was a negative correlation between serum CA153 and estimated glomerular filtration rate (GFR) (r = -.229, P = .002) in whole patients with T2DM; similarly, the correlations were observed in both women and men (r = -.228, P = .028 for women, r = -.231, P = .028 for men). Multiple linear regression analysis suggested that serum CA153 was still significantly correlated with estimated GFR (beta = -0.286, P < .001).

CONCLUSIONS

Serum CA153 is negatively correlated with estimated GFR in patients with T2DM, and serum CA153 may be a potentially useful clinical biomarker to assess renal function in the study population.

Synthesis and Immunological Evaluation of a Multicomponent Cancer Vaccine Candidate Containing a Long MUC1 Glycopeptide

A fully synthetic MUC1-based cancer vaccine was designed and chemically synthesized containing an endogenous helper T-epitope (MHC class II epitope). The vaccine elicited robust IgG titers that could neutralize cancer cells by antibody-dependent cell-mediated cytotoxicity (ADCC). It also activated cytotoxic T-lymphocytes. Collectively, the immunological data demonstrate engagement of helper T-cells in immune activation. A synthetic methodology was developed for a penta-glycosylated MUC1 glycopeptide, and antisera of mice immunized by the new vaccine recognized such a structure. Previously reported fully synthetic MUC1-based cancer vaccines that elicited potent immune responses employed exogenous helper T-epitopes derived from microbes. It is the expectation that the use of the newly identified endogenous helper T-epitope will be more attractive, because it will activate cognate CD4+ T-cells that will provide critical tumor-specific help intratumorally during the effector stage of tumor rejection and will aid in the generation of sustained immunological memory.

Generation and characterization of a monoclonal antibody to the cytoplasmic tail of MUC16

MUC16 is a large transmembrane mucin expressed on the apical surfaces of the epithelium covering the ocular surface, respiratory system and female reproductive tract. The transmembrane mucin is overexpressed by ovarian carcinomas, it is one of the most frequently used diagnostic markers for the disease and it is considered a promising target for immunotherapeutic intervention. Immunodetection of the mucin has to date been through antibodies that recognize its exceptionally large ectodomain. Similar to other membrane anchored mucins, MUC16 has a short cytoplasmic tail (CT), but studies of the biological relevance of the C-terminal domain of MUC16 has been limited by lack of availability of monoclonal antibodies that recognize the native CT. Here, we report the development of a novel monoclonal antibody to the CT region of the molecule that recognizes native MUC16 and its enzymatically released CT region. The antibody is useful for immunoprecipitation of the released CT domain as demonstrated with the OVCAR3 ovarian cancer cell line and can be used for detailed cytolocalization in cells as well as in frozen sections of ocular surface and uterine epithelium.

Mechanisms of miR-145 regulating invasion and metastasis of ovarian carcinoma

MicroRNA-145 (miR-145) can regulate tumor cell invasion, metastasis, apoptosis, proliferation and stem cell differentiation. However, the molecular mechanisms of miR-145 used to regulate ovarian invasion and metastasis remain to be determined. In this study, Transwell cell migration and wound healing assays were used to detect the effects of miR-145 upregulation on ovarian carcinoma cell invasion and metastasis, respectively. The MUC1 expression vector, together with quantitative real-time PCR and Western blotting, was used to investigate the effects of miR-145 on E-cadherin (E-cad)-induced cell invasion and the related molecular mechanisms. The results showed that miR-145 mimics could inhibit SKOV3 cell invasion and metastasis. MiR-145 inhibited mucin 1 (MUC1) post-transcriptional expression by binding to its 3'-untranslated region. The epithelial mesenchymal transition marker E-cad, which is a downstream molecule of MUC1, was promoted by miR-145 overexpression. Furthermore, the E-cad protein level was inversely correlated with MUC1 expression in SKOV3 cells. These observations indicated that promotion of E-cad signaling induced by miR-145 was restrained by MUC1 inhibition. Thus, miR-145 may serve as a tumor suppressor which can downregulate E-cad expression by targeting MUC1, leading to the inhibition of tumor invasion and metastasis. Using miR-145 mimics may be a rational approach for therapeutic applications in ovarian carcinoma in the future.