Mucin Research Articles

Grape seed oil attenuates sodium arsenite-induced gastric, hepatic and colonic damage in Wistar rats

ABSTRACT Arsenic exposure is associated with numerous morbidities due to dysfunction of various organ systems including the gastrointestinal tract. We investigated the protective effect of grape seed oil (GSO) against sodium arsenite (NaAsO2)-induced gastric, hepatic and colonic injuries in rats. Twenty-four male Wistar rats were divided into four groups of six as follows: Group A (control) received saline; group B received NaAsO2 (2.5 mg/kg) orally for 7 days; group C were treated concurrently with NaAsO2 and GSO (2 ml/kg), while group D received only GSO. Administration of NaAsO2 induced significant (p < 0.05) increases in alanine aminotransferase (ALT) and aspartate aminotransferase (AST); increased periodic acid Schiff (PAS) staining for mucus and increased goblet cell numbers in the stomach and colon; inflammatory cell infiltration and vascular congestion and alterations in the fecal bacterial flora. GSO supplementation generally promoted a reversal of changes induced by NaAsO2 towards control levels. Additionally, there was increased immunohistochemically detected expression of colonic B-cell lymphoma-1 (Bcl-2) and cytokeratins AE1/AE3, but reduced expression of mucin 1 (MUC1) and carcinoembryonic antigen (CEA) in NaAsO2 + GSO and GSO treated rats when compared with the NaAsO2 group. These results suggest that GSO promoted anti-inflammatory processes in the liver, stomach and colon, as well as opposing apoptosis in the colon, resulting in significant attenuation of damage to these tissues.

Non‐Natural MUC1 Glycopeptide Homogeneous Cancer Vaccine with Enhanced Immunogenicity and Therapeutic Activity

AbstractGlycopeptides derived from the glycoprotein mucin‐1 (MUC1) have shown potential as tumor‐associated antigens for cancer vaccine development. However, their low immunogenicity and non‐selective conjugation to carriers present significant challenges for the clinical efficacy of MUC1‐based vaccines. Here, we introduce a novel vaccine candidate based on a structure‐guided design of an artificial antigen derived from MUC1 glycopeptide. This engineered antigen contains two non‐natural amino acids and has an α‐S‐glycosidic bond, where sulfur replaces the conventional oxygen atom linking the peptide backbone to the sugar N‐acetylgalactosamine. The glycopeptide is then specifically conjugated to the immunogenic protein carrier CRM197 (Cross‐Reactive Material 197), a protein approved for human use. Conjugation involves selective reduction and re‐bridging of a disulfide in CRM197, allowing the attachment of a single copy of MUC1. This strategy results in a chemically defined vaccine while maintaining both the structural integrity and immunogenicity of the protein carrier. The vaccine elicits a robust Th1‐like immune response in mice and generates antibodies capable of recognizing human cancer cells expressing tumor‐associated MUC1. When tested in mouse models of colon adenocarcinoma and pancreatic cancer, the vaccine is effective both as a prophylactic and therapeutic use, significantly delaying tumor growth. In therapeutic applications, improved outcomes were observed when the vaccine was combined with an anti‐programmed cell death protein 1 (anti‐PD‐1) checkpoint inhibitor. Our strategy reduces batch‐to‐batch variability and enhances both immunogenicity and therapeutic potential. This site‐specific approach disputes a prevailing dogma where glycoconjugate vaccines require multivalent display of antigens.

Study repair function of mucin-2 on the tight junction protein of uterine epithelial cells under bacterial endotoxins

To analysis repair function of mucin-2(MUC2) and glycoprotein particles on the tight junction protein of uterus under bacterial endotoxins. In this experiment, we showed that the thicker mucus layer of the uterus is used to prevent the translocation of endotoxin at 21d postdelivery. When endotoxin acts on the uterus to thin its mucous layer, the cells in the lamina propria of the uterus secrete a large number of glycoprotein particles at 27d postdelivery. Due to a significantly decrease in the expression of glycosyltransferase, the glycoprotein particles are incompletely glycosylation MUC2, which can interact with the cell membrane and are released in large quantities in the form of exocytosis. These glycoprotein particles can significantly repair tight junction proteins in the inter-cellular space and significantly increase the expression of Claudin-1, JAM (Junction adhesion molecule-A), E-cadherin, ZO-1(Zonula occludens-1) and desmosome proteins after endotoxin treatment. The results of the present study show that endotoxins can thin the uterine mucus layer and accelerate the release of incompletely glycosylated MUC2 from lamina propria cells. In inter-cellular spaces, MUC2 can increase its expression levels and distribution area to repair the tight junction structure of cells with larger gaps. Further strengthening of the barrier prevents endotoxin translocation by repairing the tight junction structure of uterine epithelial cells.

A Multiple Targeting Genome Editing System for Remodulation of Circulating Malignant Cells to Eliminate Cancer Immunosuppression and Restore Immune Responses.

Cancer immunotherapy, which aims to eliminate cancer immunosuppression and reactivate anticancer immunity, holds great promise in oncology treatments. However, it is challenging to accurately study the efficacy of immunotherapy based on human-derived cells through animal experiments due to xenogeneic immune rejection. Herein, a personalized and precise strategy to evaluate the effectiveness of immunotherapy using the blood samples of cancer patients is presented. Through the utilization of multiple cancer-targeting delivery system decorated with the epidermal growth factor receptor (EGFR)-specific aptamer CL4 and the AXL-specific aptamer GL21.T to achieve superior efficiency in delivering the genome editing plasmid for MUC1 knockout, effective modulation on the behavior of circulating malignant cells (CMCs) is realized. After genome editing, both mucin 1 (MUC1) and programmed death-ligand 1 (PD-L1) are significantly downregulated in CMCs. The elimination of immunosuppression results in markedly enhanced secretion of pro-inflammatory anticancer cytokines encompassing interleukins 2, 12, and 15 and interferon-γ by immune cells. The study not only provides a strategy to overcome immunosuppression but also yields critical insights for personalized immunotherapy approaches.

Targeting Human Pancreatic Cancer with a Fluorophore-Conjugated Mucin 4 (MUC4) Antibody: Initial Characterization in Orthotopic Cell Line Mouse Models.

Background/Objectives: Pancreatic cancer is the third leading cause of death related to cancer. The only possible cure presently is complete surgical resection; however, this is limited by difficulty in clearly defining tumor margins. Enhancement of the visualization of pancreatic ductal adenocarcinoma (PDAC) tumor margins using near-infrared dye-conjugated tumor-specific antibodies was pioneered by using anti-CEA, anti-CA19.9, and anti-MUC5AC in orthotopic mouse models of pancreatic cancer. Recently, an antibody to Mucin 4 (MUC4) conjugated to a fluorescent probe has shown promise in targeting colon tumors in orthotopic mouse models. Methods: In the present study, we targeted pancreatic cancer using an anti-MUC4 antibody conjugated to IRDye800 (anti-MUC4-IR800) in orthotopic mouse models. Two pancreatic cancer human cell lines were used, SW1990 and CD18/HPAF. Results: Anti-MUC4-IR800 targeted the two pancreatic cancer cell line tumors in orthotopic mouse models with high tumor-to-pancreas ratios and high tumor-to-liver ratios, with greater targeting seen in SW1990. Conclusions: The present results suggest anti-MUC4-IR800's potential to be used in fluorescence-guided surgical resection of pancreatic cancer.

MUC17 is a potential new prognostic biomarker and promotes pancreatic cancer progression in obstructive jaundice.

Our working group has previously shown that bile acids (BAs) accelerate carcinogenic processes in pancreatic cancer (PC) in which mucin 4 (MUC4) expression has a central role. However, the role of other mucins in PC are less clear, especially in bile-induced cancer progression. The study aim was to investigate expression of MUC17 in BAs- or human serum-treated pancreatic ductal adenocarcinoma (PDAC) cell lines and use different assays with RNA silencing/overexpression to study the role of MUC17 in cancer progression. Protein expression of MUC17 was evaluated in 55 human pancreatic samples by immunohistochemistry, and Kaplan-Meier survival analysis was used to compare survival curves. Expression of MUC17 increased in PDAC patients, especially in obstructive jaundice (OJ) and the elevated MUC17 expression associated with poorer overall survival (10.66±1.99 vs. 15.05±2.03 months; Log rank: 0.0497). Treatment of Capan-1 and AsPC-1 cells with BAs or with human serum obtained from PDAC + OJ patients enhanced the expression of MUC17, as well as the proliferative potential of the cells, whereas knockdown of MUC17 alone or in combination with MUC4 decreased BAs-induced carcinogenic processes. Our results demonstrated that MUC17 has a central role in bile-induced PC progression, and in addition to MUC4, this isoform also can be used as a novel prognostic biomarker.

MUC16 Retention after Neoadjuvant Chemotherapy in Pancreatic Ductal Adenocarcinoma.

Background/Objectives: Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis. Currently, surgical resection is the only potentially curative treatment. Unfortunately, less than 20% of PDAC patients are eligible for surgical resection at diagnosis. In the past few decades, neoadjuvant chemotherapy treatment (NCT) has been investigated as a way to downstage PDAC tumors for surgical resection. Fluorescence-guided surgery (FGS) is a technique that can aid in increasing complete resection rates by enhancing the tumor through passive or active targeting of a contrast agent. In active targeting, a probe (e.g., antibody) binds a protein differentially upregulated in the tumor compared to normal tissue. Mucin 16 (MUC16), a transmembrane glycoprotein, has recently been explored as an FGS target in preclinical tumor models. However, the impact of chemotherapy on MUC16 expression is unknown. Methods: To investigate this issue, immunohistochemistry was performed on PDAC patient samples. Results: We found that MUC16 expression was retained after NCT in patient samples (mean expression = 5.7) with minimal change in expression between the matched diagnostic (mean expression = 3.66) and PDAC NCT patient samples (mean expression = 4.5). Conclusions: This study suggests that MUC16 is a promising target for FGS and other targeted therapies in PDAC patients treated with NCT.

Preventative Cancer Vaccine-Elicited Human Anti-MUC1 Antibodies Have Multiple Effector Functions.

Mucin-1 (MUC1) is a transmembrane glycoprotein that is overexpressed and hypoglycosylated in premalignant and malignant epithelial cells compared to normal cells, creating a target antigen for humoral and cellular immunity. Healthy individuals with a history of advanced colonic adenomas and at high risk for colon cancer were enrolled in a clinical trial to evaluate the feasibility of using a MUC1 peptide vaccine to prevent colon cancer. Anti-MUC1 antibodies elicited by this vaccine were cloned using peripheral blood B cells and sera collected two weeks after a one-year booster. Twelve of these fully human monoclonal antibodies (mAb) were tested for binding to MUC1+ target cells, and three with the highest binding were further evaluated for various effector functions important for tumor rejection. Immune cells were incubated together with target cells expressing variations in the number, distance, and membrane anchoring properties of the MUC1 epitope in the presence of each mAb. All three mAbs mediated antibody-dependent cytokine release (ADCR), antibody-dependent cellular cytotoxicity (ADCC), and antibody-dependent cellular phagocytosis (ADCP). Two also mediated antibody-dependent trogocytosis/trogoptosis (ADCT). None were capable of complement-dependent cytotoxicity (CDC). ADCP and ADCT functions were more efficient when antibodies bound epitopes proximal to and anchored to the membrane, providing insight for future therapeutic antibody validation strategies.

Hypomethylation-associated ELF3 helps nasopharyngeal carcinoma to escape immune surveillance via MUC16-mediated glycolytic metabolic reprogramming.

Immune escape and metabolic reprogramming are two essential hallmarks of cancer. Mucin-16 (MUC16) has been linked to glycolysis and immune response in different cancers. However, its involvement in nasopharyngeal carcinoma (NPC) has not been well described. We seek to dissect the functions and detailed mechanisms of MUC16 in NPC. Bioinformatics prediction was performed to identify NPC-related molecules. MUC16 was significantly enhanced in NPC tissues, which was correlated with the advanced tumor stage of patients. Lentiviral plasmids-mediated MUC16 deletion inhibited the malignant behavior of NPC cells, and glycolysis inhibition by MUC16 deletion blocked immune escape in NPC cells. E74-like factor 3 (ELF3) bound to the MUC16 promoter promotes the transcription of MUC16. MUC16 overexpression reversed the repressive effect of ELF3 silencing on glycolysis and immune escape in NPC and accelerated tumor growth in vivo. Overexpression of ELF3 in NPC was associated with reduced DNA methylation in its promoter. Our findings revealed the role of the ELF3/MUC16 axis in the immune escape and metabolic reprogramming of NPC, providing potential therapeutic targets for NPC.NEW & NOTEWORTHY We identified the functions of E74-like factor 3 (ELF3) in glycolysis and immune escape of nasopharyngeal carcinoma cells for the first time. As a transcription factor, ELF3 promoted mucin-16 (MUC16) expression by binding to its promoter, leading to the glycolysis-mediated immune escape of nasopharyngeal carcinoma (NPC) cells. Targeting the ELF3/MUC16 axis generates a superior antitumor immune response, which will help establish a novel approach to restore protective antitumor immunity for NPC immunotherapy.

Huaiyu pill alleviates inflammatory bowel disease in mice blocking toll like receptor 4/ myeloid differentiation primary response gene 88/ nuclear factor kappa B subunit 1 pathway.

To investigate the therapeutic effects of Huaiyu pill (, HYP) on inflammatory bowel disease (IBD) and the underlying mechanisms have not been elucidated. To establish the IBD model, mice were administered with dextran sulfate sodium (DSS). Mice were intragastrically pre-treated with sulfasalazine (SASP) and HYP. Disease activity index (DAI) and colon length were monitored, and the colonic tissues were subjected to hematoxylin-eosin staining. Pro-inflammatory factors and vascular inflammation-related proteins were determined using enzyme-linked immunosorbent assay (ELISA). The potential mechanisms of HYP were examined using network pharmacology analysis.The expressions of zona occludens 1 (ZO-1), occludin, toll like receptor 4 (TLR4), myeloid differentiation primary response gene 88 (MYD88), and nuclear factor kappa B p65 subunit (NF-κB p65) in colon tissues were examined using Western blotting or immunohistochemical analyses. Pre-treatment with HYP enhanced the colon length, decreased DAI scores, and mitigated histopathological alterations in DSS-treated mice. HYP alleviated intestinal inflammation by downregulating the levels of interleukin 1 beta (IL-1β), interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α) and interleukin 17 (IL-17). Additionally, HYP suppressed the disruption of the gut barrier by upregulating the ZO-1, occludin, and mucin 2 (MUC2) levels and downregulating the endothelin 1 (ET-1) and erythropoietin (EPO) levels. Network pharmacological analysis and experimental results revealed that HYP downregulated the colonic tissue levels of TLR4, MYD88, and NF-κB p65 in DSS-treated mice. This study investigated the in vivotherapeutic effects of HYP on IBD and the underlying molecular mechanisms. These findings provide an experimental foundation for the clinical application of HYP.

A novel arabinogalactan extracted from Epiphyllum oxypetalum (DC.) Haw improves the immunity and gut microbiota in cyclophosphamide‐induced immunosuppressed mice

AbstractA novel type I arabinogalactan (AG‐I) polysaccharide (EPS) from Epiphyllum oxypetalum (DC.) Haw's flowers is hypothesized to possess immunomodulatory activity. This study investigated EPS's effects on immune functions and its potential mechanism for enhancing intestinal health in immunosuppressed mice. The results showed that supplementing EPS significantly alleviated immune organ damage, increased the thymus index (p &lt; 0.01), and regulated the key immune factors, including the tumor necrosis factor‐alpha (TNF‐α), immunoglobulin A (IgA), and complement 3 (C3) in the liver (p &lt; 0.05). EPS promoted the expression of intestinal immune barrier and chemical barrier proteins such as interferon‐γ (IFN‐γ) and mucin 2 (MUC2) (p &lt; 0.05), effectively repairing intestinal damage. EPS improved the diversity and structure of intestinal microbiota in immunosuppressed mice (p &lt; 0.05) and significantly altered the abundance of intestinal immune‐related microbial taxa, including Lactobacillaceae and Lactobacillus (p &lt; 0.01). Furthermore, EPS supplementation altered intestinal lactic acid metabolism, significantly increasing lactic acid levels by up to 3.4‐fold (p &lt; 0.01), and enhanced the expression of Gpr81, Wnt3a, and β‐catenin proteins at the bottom of the colonic crypts, which may repair the intestinal physical barrier. Overall, EPS represents a novel AG‐I immunomodulatory dietary polysaccharide that enhances immunity and improves gut health.

Impedimetric Biosensor of Silver Molybdate Anchored on rGO Sheet for Detection of Breast Cancer Mucin‐1 Biomarker

AbstractThis work aims to detect the Mucin‐1 (MUC1) breast cancer biomarker using a label‐free impedimetric biosensor of silver molybdate anchored on reduced graphene oxide (Ag2MoO4‐rGO). A hydrothermal method has been employed to synthesize the Ag2MoO4‐rGO nanocomposite. Subsequently, they have been studied through analytical characterization techniques to study the electrocatalytic activity, electroactive surface area, surface functionalities, and morphologies to determine the suitability of the material for biosensor fabrication. Results reveal that the Ag2MoO4‐rGO nanocomposite possesses excellent electroconductivity and surface properties that have significant characteristics for the biosensor's performance. A biosensor has been fabricated by the immobilization of Ag2MoO4‐rGO nanocomposite and anti‐MUC1 antibody on a glassy carbon electrode. The electroanalytical studies revealed that the biosensor has excellent sensitivity and detection performance having a wide linearity of 100 fg mL−1–5 ng mL−1 and a low limit of detection of 2.70 fg mL−1. Moreover, the remarkable selectivity, reproducibility, stability, and detection in serum samples determine the high performance of the biosensor. Therefore, the presented biosensor could be a promising diagnostic tool that shows the remarkable potential to efficiently detect the breast cancer MUC1 biomarker in patient's serum samples.

Proinflammatory Microenvironment in Adenocarcinoma Tissue of Colorectal Carcinoma.

Cancer-promoting proinflammatory microenvironment influences colorectal cancer (CRC) development. We examined the biomarkers of inflammation, intestinal differentiation, and DNA activity correlated with the clinical parameters to observe progression and prognosis in the adenocarcinoma subtype of CRC. Their immunohistology, immunoblotting, and RT-PCR analyses were performed in the adenocarcinoma and neighboring healthy tissues of 64 patients with CRC after routine colorectal surgery. Proinflammatory nuclear factor kappa B (NFκB) signaling as well as interleukin 6 (IL-6) and S100 protein levels were upregulated in adenocarcinoma compared with nearby healthy colon tissue. In contrast to nitrotyrosine expression, the oxidative stress marker 8-Hydroxy-2'-deoxyguanosine (8-OHdG) was increased in adenocarcinoma tissue. Biomarkers of intestinal differentiation β-catenin and mucin 2 (MUC2) were inversely regulated, with the former upregulated in adenocarcinoma tissue and positively correlated with tumor marker CA19-9. Downregulation of MUC2 expression correlated with the increased 2-year survival rate of patients with CRC. Proliferation-related mammalian target of rapamycin (mTOR) signaling was activated, and Ki67 frequency was three-fold augmented in positive correlation with metastasis and cancer stage, respectively. Conclusion: We demonstrated a parallel induction of oxidative stress and inflammation biomarkers in adenocarcinoma tissue that was not reflected in the neighboring healthy colon tissue of CRC. The expansiveness of colorectal adenocarcinoma was confirmed by irregular intestinal differentiation and elevated proliferation biomarkers, predominantly Ki67. The origin of the linked inflammatory factors was in adenocarcinoma tissue, with an accompanying systemic immune response.

Abstract B051: Influence of MUC16 on the immune tumor microenvironment of PDAC

Abstract Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease. In most cases, PDAC initiation results from oncogenic KRAS mutations, that act in part by directly increasing levels of a glycoprotein called Mucin-16 (MUC16). MUC16 is virtually absent in the normal pancreas, expressed on tumor cells in &amp;gt;65% of PDAC and is a marker of poor prognosis. The cell autonomous roles of MUC16 involve signaling through the ErbB-1/2/3 axes, and eliciting downstream AKT and GSK-3β activation to promote cell proliferation and survival. PDAC has a very interesting “immune cold” tumor microenvironment (TME) that is devoid of anti-tumor T cells and is instead flush with pro-tumor myeloid cells like macrophages. However, the role of MUC16 in influencing immune cells, particularly macrophages has not been investigated. Methods: We use immunohistochemistry to check for macrophage populations in spontaneous and orthotopic models of PDAC, KPC (LSL-Kras G12D/+ ; LSL-Trp53 R172H/+ ; Pdx-1- Cre) and a derived KPC-MUC16 knockout (KPC-M16KO). Orthotopic implantation with KPC and KPC-M16- cells was done to assess survival. In vitro cytokine screening from M16+/- cells was done to understand cytokine players in MUC16-mediated immunosuppression. Clodronate liposomes (CL) and neutral control liposomes (NL) were used to deplete macrophages in orthotopically implanted KPC and KPC-M16- tumor-bearing mice, and flow cytometry was conducted to profile macrophages and T cells in the pancreas and spleens at the experimental endpoint. Results: We show that KPC-M16KO tumors have decreased M2-like macrophages, and a modest increase in M1-like macrophages, leading to a high M1/M2 ratio suggesting reduced immune suppressed cells in the KPC-M16KO models. KPC-M16KO tumor-bearing mice showed longer survival compared to the KPC group. In addition, we detect low levels of CCL2 and Serpin-E1 in cell lines and tumor tissues from KPC-M16KO models suggesting that they could serve as potential regulators of macrophage infiltration and M2-like polarization downstream of MUC16. Siglec-E (murine homolog of human Siglec-7/9) was also downregulated in KPC-M16KO tumors, suggesting MUC16-Siglec mediated immunosuppression as another mechanism. CL administration (versus NL) resulted in significant macrophage depletion in the spleens of mice with KPC and KPC-M16KO tumors, however, such depletion was not robust in the pancreas. Immune profiling studies showed a high M1/M2 ratio in the spleen and pancreas of mice treated with CL, suggesting a tumor cell-macrophage crosstalk, that could mediate M2-like macrophage states in a macrophage-rich TME. Mice treated with CL have smaller tumors, and KPC-M16KO+CL group had the smallest tumors, indicative that dual disruption of MUC16 and macrophages lowers tumor burden. Conclusions: These results suggest that MUC16 plays a crucial role in modulating the tumor immune microenvironment by increasing the accumulation of immunosuppressive macrophages in PDAC. Citation Format: Christabelle Rajesh, Satish Sagar, Prakash Radhakrishnan. Influence of MUC16 on the immune tumor microenvironment of PDAC [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr B051.

Non-Natural MUC1 Glycopeptide Homogeneous Cancer Vaccine with Enhanced Immunogenicity and Therapeutic Activity.

Glycopeptides derived from the glycoprotein mucin-1 (MUC1) have shown potential as tumor-associated antigens for cancer vaccine development. However, their low immunogenicity and non-selective conjugation to carriers present significant challenges for the clinical efficacy of MUC1-based vaccines. Here, we introduce a novel vaccine candidate based on a structure-guided design of an artificial antigen derived from MUC1 glycopeptide. This engineered antigen contains two non-natural amino acids and has an α-S-glycosidic bond, where sulfur replaces the conventional oxygen atom linking the peptide backbone to the sugar N-acetylgalactosamine. The glycopeptide is then specifically conjugated to the immunogenic protein carrier CRM197 (Cross-Reactive Material 197), a protein approved for human use. Conjugation involves selective reduction and re-bridging of a disulfide in CRM197, allowing the attachment of a single copy of MUC1. This strategy results in a chemically defined vaccine while maintaining both the structural integrity and immunogenicity of the protein carrier. The vaccine elicits a robust Th1-like immune response in mice and generates antibodies capable of recognizing human cancer cells expressing tumor-associated MUC1. When tested in mouse models of colon adenocarcinoma and pancreatic cancer, the vaccine is effective both as a prophylactic and therapeutic use, significantly delaying tumor growth. In therapeutic applications, improved outcomes were observed when the vaccine was combined with an anti-programmed cell death protein 1 (anti-PD-1) checkpoint inhibitor. Our strategy reduces batch-to-batch variability and enhances both immunogenicity and therapeutic potential. This site-specific approach disputes a prevailing dogma where glycoconjugate vaccines require multivalent display of antigens.

A higher dietary alpha-linolenic acid intake is associated with lower colorectal cancer risk based on MUC4 rs2246901 variant among Korean adults

Alpha-linolenic acid (C18:3n-3 [ALA]) intake may have a beneficial effect in reducing cancer risk; however, its association with colorectal cancer (CRC) risk remains conflicted. Additionally, ALA was emphasized as being associated with mucins, an important glycoproteins family within the intestine. Thus, we hypothesized that a higher dietary ALA intake may reduce the risk of CRC and this preventive effect has an interaction with mucin 4 (MUC4) rs2246901. We conducted a case-control study at the National Cancer Center in Korea, involving 1039 cases and 1982 controls, aiming to determine the interaction of the MUC4 rs2246901 polymorphism and ALA intake in CRC risk. Dietary ALA intake was collected via semiquantitative food frequency questionnaire (SQFFQ), categorizing by 4 quartiles. We evaluated the odds ratios (ORs) and 95% confidence intervals (CIs) through unconditional logistic regression models. Higher dietary ALA intake was found to be inversely associated with CRC risk (adjusted OR = 0.58; 95% CI, 0.45–0.75, P for trend < .001). No significant association between MUC4 rs2246901 polymorphism and CRC risk was found. In a recessive model, MUC4 rs2246901 seemed to modify this association; participants with at least 1 major allele and higher ALA intake had a significantly lower CRC risk than those who had a lower intake (adjusted OR = 0.56; 95% CI, 0.43–0.72; P interaction = .047). A higher dietary ALA was proposed as a potential protective nutrient against CRC. Moreover, this association might be influenced by presence of the MUC4 rs2246901 polymorphism.

2′-Fucosyllactose alleviate immune checkpoint blockade-associated colitis by reshaping gut microbiota and activating AHR pathway

Immune checkpoint blockade (ICB) therapeutics are highly effective in cancer immunotherapy, but gastrointestinal toxicity limited the application. Intestinal microbiota plays a crucial role in ICB-associated colitis. 2′-Fucosyllactose (2′FL) is most abundance prebiotic in human milk that can reshape gut microbiota and exert immune regulatory effect. The study aimed to determine the effects of 2′FL on ICB-associated colitis and to uncover the mediating mechanism. ICB-associated colitis was induced by the ipilimumab and dextran sulfate sodium. Oral administration of 2′FL (0.6 g/(kg∙day)) ameliorated ICB-induced colitis by enhancing regulatory T cells (Treg) and the M2/M1 ratio of macrophages in colon. 2′FL treatment also increased the expression of tight junction proteins (zonula occludens-1 (ZO-1) and mucin 2 (MUC2)) and antioxidant stress indicators (superoxide dismutase (SOD) and catalase (CAT)). In addition, administration of 2′FL increased the abundance of Bifidobacterium and Lactobacillus, and elevated the levels of microbial metabolites, such as indole-3-lactic acid (ILA), which activated the aryl hydrocarbon receptor ligands (AHR) pathway. The protective effect of 2′FL was abolished upon depletion of gut microbiota, and ILA treatment partially simulated the protective effect of 2′FL. Notably, 2′FL did not exhibit inhibition of antitumor immunity. These findings suggest that 2′FL could serve as a potential protective strategy for ICB-associated colitis by modulating the intestinal microbiota and bacterial metabolites.

ALKBH5-Mediated m6A Modification Drives Apoptosis in Renal Tubular Epithelial Cells by Negatively Regulating MUC1.

Dysregulation of renal tubular epithelial cell (RTEC) apoptosis is one of the critical steps underlying the occurrence and development of nephrolithiasis. Although N6-methyladenosine (m6A) modification has been extensively studied and associated with various pathologic processes, research onits specific role in RTEC injury and apoptosis remains limited. In this study, we found that overexpression of ALKBH5 reduced the level of m6A modification in RTEC cells and notably promoted RTEC apoptosis. Further mechanism studies revealed that ALKBH5 mainly decreased the m6A level on the mRNA of Mucin 1 (MUC1) gene in RTECs. Moreover, ALKBH5 impaired the stability of MUC1mRNA in RTECs, leading to attenuated expression of MUC1. Finally, we determined that the ALKBH5-MUC1 axis primarily facilitated RTEC apoptosis by regulating the PI3K/Akt signaling pathway. This study revealed the critical role of the ALKBH5-MUC1-PI3K/Akt regulatory system in RTEC apoptosis and provided new therapeutic targets for treating nephrolithiasis.

A novel immunofluorescence study of Lingual Salivary Glands in the Egyptian Tortoise (Testudo kleinmanni) and its ecological significance

The Egyptian tortoise (Testudo kleinmanni) is remarkably adapted to its harsh desert environment, a characteristic that is crucial for its survival under extreme conditions. This study was aimed at providing a deeper understanding of the lingual salivary gland structures in the Egyptian tortoise and examining how these structures help the tortoise manage hydration and nutrition in arid conditions. Utilizing a combination of light microscopy and immunofluorescence, this research introduced pioneering methods involving seven different antibodies, marking a first in the study of reptilian salivary glands. Our investigations categorized the tortoise’s salivary glands into papillary and non-papillary types. The papillary glands were further classified into superficial, deep, interpapillary, and intraepithelial salivary glands, while non-papillary glands included superficial and deep lingual types. Structurally, these glands are organized into lobules, delineated by interlobular septa, and are equipped with a duct system comprising interlobular, intercalated, and main excretory ducts with gland openings on the tongue's surface and the papillae surfaces. Notably, the superficial glands displayed both tubuloalveolar and acinar configurations, whereas the deep lingual glands were exclusively acinar. Immunofluorescence results indicated that α-smooth muscle actin (α-SMA) was prevalent in myoepithelial cells, myofibroblasts, and blood vessels, suggesting their integral role in glandular function and support. E-cadherin was predominantly found in epithelial cells, enhancing cell adhesion and integrity, which are critical for efficient saliva secretion. Importantly, Mucin 1 (MUC1) and Mucin 5B (MUC5B) staining revealed that most glands were mucous in nature, with MUC5B specifically marking mucin within secretory cells, confirming their primary function in mucous secretion. PDGFRα and CD34 highlighted the presence of telocytes and stromal cells within the glandular and interlobular septa, indicating a role in structural organization and possibly in regenerative processes. Cytokeratin 14 expression was noted in the basal cells of the glands, underscoring its role in upholding the structural foundation of the epithelial barrier. In conclusion, this detailed morphological and immunological characterization of the Egyptian tortoise’s salivary glands provides new insights into their complex structure and essential functions. These findings not only enhance our understanding of reptilian physiology but also underline the critical nature of salivary glands in supporting life in arid environments. This study's innovative use of a broad range of immunofluorescence markers opens new avenues for further research into the adaptive mechanisms of reptiles.

Detection of Tumor-Associated Autoantibodies in the Sera of Pancreatic Cancer Patients Using Engineered MUC1 Glycopeptide Nanoparticle Probes.

Pancreatic cancer is one of the deadliest cancers worldwide, mainly due to late diagnosis. Therefore, there is an urgent need for novel diagnostic approaches to identify the disease as early as possible. We have developed a diagnostic assay for pancreatic cancer based on the detection of naturally occurring tumor associated autoantibodies against Mucin-1 (MUC1) using engineered glycopeptides on nanoparticle probes. We used a structure-guided approach to develop unnatural glycopeptides as model antigens for tumor-associated MUC1. We designed a collection of 13 glycopeptides to bind either SM3 or 5E5, two monoclonal antibodies with distinct epitopes known to recognize tumor associated MUC1. Glycopeptide binding to SM3 or 5E5 was confirmed by surface plasmon resonance and rationalized by molecular dynamics simulations. These model antigens were conjugated to gold nanoparticles and used in a dot-blot assay to detect autoantibodies in serum samples from pancreatic cancer patients and healthy volunteers. Nanoparticle probes with glycopeptides displaying the SM3 epitope did not have diagnostic potential. Instead, nanoparticle probes displaying glycopeptides with high affinity for 5E5 could discriminate between cancer patients and healthy controls. Remarkably, the best-discriminating probes show significantly better true and false positive rates than the current clinical biomarkers CA19-9 and carcinoembryonic antigen (CEA).