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1.
Nat Commun ; 15(1): 3771, 2024 May 04.
Article in English | MEDLINE | ID: mdl-38704377

ABSTRACT

Ovarian metastasis is one of the major causes of treatment failure in patients with gastric cancer (GC). However, the genomic characteristics of ovarian metastasis in GC remain poorly understood. In this study, we enroll 74 GC patients with ovarian metastasis, with 64 having matched primary and metastatic samples. Here, we show a characterization of the mutation landscape of this disease, alongside an investigation into the molecular heterogeneity and pathway mutation enrichments between synchronous and metachronous metastasis. We classify patients into distinct clonal evolution patterns based on the distribution of mutations in paired samples. Notably, the parallel evolution group exhibits the most favorable prognosis. Additionally, by analyzing the differential response to chemotherapy, we identify potential biomarkers, including SALL4, CCDC105, and CLDN18, for predicting the efficacy of paclitaxel treatment. Furthermore, we validate that CLDN18 fusion mutations improve tumor response to paclitaxel treatment in GC with ovarian metastasis in vitro and vivo.


Subject(s)
Biomarkers, Tumor , Mutation , Ovarian Neoplasms , Paclitaxel , Stomach Neoplasms , Paclitaxel/therapeutic use , Humans , Stomach Neoplasms/genetics , Stomach Neoplasms/drug therapy , Stomach Neoplasms/pathology , Female , Ovarian Neoplasms/genetics , Ovarian Neoplasms/drug therapy , Ovarian Neoplasms/pathology , Biomarkers, Tumor/genetics , Claudins/genetics , Claudins/metabolism , Evolution, Molecular , Animals , Middle Aged , Prognosis , Cell Line, Tumor , Mice , Transcription Factors/genetics , Transcription Factors/metabolism , Aged , Antineoplastic Agents, Phytogenic/therapeutic use
2.
Biomed Res Int ; 2024: 8544837, 2024.
Article in English | MEDLINE | ID: mdl-38803515

ABSTRACT

The loss of RAB25 expression-RAS superfamily of GTPase characteristic of numerous breast cancers-corresponds with H-RAS point mutations, particularly in triple-negative breast cancers (TNBC), a subtype associated with a poor prognosis. To address the poorly understood factors dictating the progression of TNBC tumors, we examine the cooperative effects that loss of RAB25 expression in human mammary epithelial cell (HMEC) lines with H-RAS mutations confers in tumorigenesis. HMECs were immortalized by transduction with LXSN CDK4 R24C, a mutant form of cyclin-dependent kinase, followed by transduction with hTERT, a catalytic subunit of the telomerase enzyme. We found that with the loss of RAB25 and overexpression of mutant H-RAS61L, immortal HMECs transformed toward anchorage-independent growth and acquired an increased ability to migrate. Furthermore, cells express low CD24, high CD44, and low claudin levels, indicating stem-like properties upon transformation. Besides, loss of RAB25 and overexpression of H-RAS61L resulted in increased expression of transcription factors Snail and Slug that drive these cells to lose E-cadherin and undergo epithelial-mesenchymal transition (EMT). This study confirms that loss of RAB25 and overexpression of mutant H-RAS can drive HMECs toward a mesenchymal stem-like state. Our findings reveal that RAB25 functions as a tumor suppressor gene, and loss of RAB25 could serve as a novel biomarker of the claudin-low type of TNBC.


Subject(s)
Cell Transformation, Neoplastic , Claudins , Epithelial Cells , Epithelial-Mesenchymal Transition , rab GTP-Binding Proteins , Humans , rab GTP-Binding Proteins/metabolism , rab GTP-Binding Proteins/genetics , Cell Transformation, Neoplastic/genetics , Cell Transformation, Neoplastic/metabolism , Epithelial Cells/metabolism , Epithelial-Mesenchymal Transition/genetics , Claudins/genetics , Claudins/metabolism , Female , Mammary Glands, Human/metabolism , Mammary Glands, Human/pathology , Triple Negative Breast Neoplasms/genetics , Triple Negative Breast Neoplasms/pathology , Triple Negative Breast Neoplasms/metabolism , Gene Expression Regulation, Neoplastic , Oncogenes/genetics , Snail Family Transcription Factors/metabolism , Snail Family Transcription Factors/genetics , Mutation/genetics
3.
Cell Mol Life Sci ; 81(1): 240, 2024 May 28.
Article in English | MEDLINE | ID: mdl-38806818

ABSTRACT

The pulmonary endothelium is a dynamic and metabolically active monolayer of endothelial cells. Dysfunction of the pulmonary endothelial barrier plays a crucial role in the acute lung injury (ALI) and acute respiratory distress syndrome (ARDS), frequently observed in the context of viral pneumonia. Dysregulation of tight junction proteins can lead to the disruption of the endothelial barrier and subsequent leakage. Here, the highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) served as an ideal model for studying ALI and ARDS. The alveolar lavage fluid of pigs infected with HP-PRRSV, and the supernatant of HP-PRRSV infected pulmonary alveolar macrophages were respectively collected to treat the pulmonary microvascular endothelial cells (PMVECs) in Transwell culture system to explore the mechanism of pulmonary microvascular endothelial barrier leakage caused by viral infection. Cytokine screening, addition and blocking experiments revealed that proinflammatory cytokines IL-1ß and TNF-α, secreted by HP-PRRSV-infected macrophages, disrupt the pulmonary microvascular endothelial barrier by downregulating claudin-8 and upregulating claudin-4 synergistically. Additionally, three transcription factors interleukin enhancer binding factor 2 (ILF2), general transcription factor III C subunit 2 (GTF3C2), and thyroid hormone receptor-associated protein 3 (THRAP3), were identified to accumulate in the nucleus of PMVECs, regulating the transcription of claudin-8 and claudin-4. Meanwhile, the upregulation of ssc-miR-185 was found to suppress claudin-8 expression via post-transcriptional inhibition. This study not only reveals the molecular mechanisms by which HP-PRRSV infection causes endothelial barrier leakage in acute lung injury, but also provides novel insights into the function and regulation of tight junctions in vascular homeostasis.


Subject(s)
Claudins , Endothelial Cells , Lung , Porcine respiratory and reproductive syndrome virus , Animals , Swine , Porcine respiratory and reproductive syndrome virus/physiology , Lung/metabolism , Lung/virology , Lung/pathology , Lung/blood supply , Endothelial Cells/metabolism , Endothelial Cells/virology , Claudins/metabolism , Claudins/genetics , Porcine Reproductive and Respiratory Syndrome/metabolism , Porcine Reproductive and Respiratory Syndrome/virology , Porcine Reproductive and Respiratory Syndrome/pathology , Claudin-4/metabolism , Claudin-4/genetics , Macrophages, Alveolar/metabolism , Macrophages, Alveolar/virology , Endothelium, Vascular/metabolism , Endothelium, Vascular/virology , Endothelium, Vascular/pathology , Cells, Cultured , Capillary Permeability , Acute Lung Injury/metabolism , Acute Lung Injury/virology , Acute Lung Injury/pathology , Cytokines/metabolism
4.
J Pharmacol Sci ; 155(3): 84-93, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38797537

ABSTRACT

The development of targeted cancer therapies based on monoclonal antibodies against tumor-associated antigens has progressed markedly over recent decades. This approach is dependent on the identification of tumor-specific, normal tissue-sparing antigenic targets. The transmembrane protein claudin-18 splice variant 2 (CLDN18.2) is frequently and preferentially displayed on the surface of primary gastric adenocarcinomas, making it a promising monoclonal antibody target. Phase 3 studies of zolbetuximab, a chimeric immunoglobulin G1 monoclonal antibody targeting CLDN18.2, combined with 5-fluorouracil/leucovorin plus oxaliplatin (modified FOLFOX6) or capecitabine plus oxaliplatin (CAPOX) in advanced or metastatic first-line gastric or gastroesophageal junction (G/GEJ) adenocarcinoma have demonstrated favorable clinical results with zolbetuximab. In studies using xenograft or syngeneic models with gastric cancer cell lines, zolbetuximab mediated death of CLDN18.2-positive human cancer cell lines via antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity in vitro and demonstrated anti-tumor efficacy as monotherapy and combined with chemotherapy in vivo. Mice treated with zolbetuximab plus chemotherapy displayed a significantly higher frequency of tumor-infiltrating CD8+ T cells versus vehicle/isotype control-treated mice. Furthermore, zolbetuximab combined with an anti-mouse programmed cell death-1 antibody more potently inhibited tumor growth compared with either agent alone. These results support the potential of zolbetuximab as a novel treatment option for G/GEJ adenocarcinoma.


Subject(s)
Antibodies, Monoclonal , Antineoplastic Combined Chemotherapy Protocols , Claudins , Stomach Neoplasms , Stomach Neoplasms/drug therapy , Stomach Neoplasms/pathology , Stomach Neoplasms/immunology , Animals , Humans , Antibodies, Monoclonal/pharmacology , Antibodies, Monoclonal/therapeutic use , Antibodies, Monoclonal/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/pharmacology , Cell Line, Tumor , Programmed Cell Death 1 Receptor/antagonists & inhibitors , Mice , Adenocarcinoma/drug therapy , Adenocarcinoma/pathology , Disease Models, Animal , Xenograft Model Antitumor Assays , Antibody-Dependent Cell Cytotoxicity/drug effects
5.
Genesis ; 62(3): e23599, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38764323

ABSTRACT

BACKGROUND: Increasing evidence suggests that circular RNA (circRNA) plays a regulatory role in the progression of renal cell carcinoma (RCC). However, the precise function and underlying mechanism of circSCNN1A in RCC progression still remain unclear. METHODS: The expression levels of circSCNN1A, microRNA-590-5p (miR-590-5p), claudin 8 (CLDN8), cyclin D1, matrix metalloprotein 2 (MMP2), MMP9, E-cadherin, N-cadherin and vimentin were detected by a quantitative real-time polymerase chain reaction and Western blotting analysis. Immunohistochemistry assay was performed to analyze the positive expression rate of CLDN8. Cell proliferation was investigated by cell colony formation, 5-Ethynyl-2'-deoxyuridine and DNA content quantitation assays. Cell migration and invasion were assessed by wound-healing and transwell invasion assays. Interactions among circSCNN1A, miR-590-5p and CLDN8 were identified by dual-luciferase reporter assay, RNA immunoprecipitation assay and RNA pull-down assay. Xenograft mouse model assay was conducted to verify the effect of circSCNN1A on tumor formation in vivo. RESULTS: CircSCNN1A and CLDN8 expression were significantly downregulated, while miR-590-5p was upregulated in both RCC tissues and cells. CircSCNN1A overexpression inhibited RCC cell proliferation, migration and invasion, accompanied by decreases of cyclin D1, MMP2, MMP9, N-cadherin and vimentin expression and an increase of E-cadherin expression. CircSCNN1A acted as a miR-590-5p sponge and regulated RCC cell processes by binding to miR-590-5p. CLDN8, a target gene of miR-590-5p, was involved in the regulation of the biological behaviors of RCC cells by miR-590-5p. In addition, circSCNN1A induced CLDN8 production by interacting with miR-590-5p. Further, circSCNN1A suppressed tumor formation in vivo. CONCLUSION: CircSCNN1A inhibited RCC cell proliferation, migration and invasion by regulating the miR-590-5p/CLDN8 pathway.


Subject(s)
Carcinoma, Renal Cell , Cell Movement , Cell Proliferation , Claudins , Gene Expression Regulation, Neoplastic , Kidney Neoplasms , MicroRNAs , Neoplasm Invasiveness , RNA, Circular , Humans , MicroRNAs/genetics , MicroRNAs/metabolism , Cell Proliferation/genetics , Carcinoma, Renal Cell/genetics , Carcinoma, Renal Cell/pathology , Carcinoma, Renal Cell/metabolism , Animals , Cell Movement/genetics , Kidney Neoplasms/genetics , Kidney Neoplasms/pathology , Kidney Neoplasms/metabolism , Mice , Cell Line, Tumor , RNA, Circular/genetics , RNA, Circular/metabolism , Claudins/genetics , Claudins/metabolism , Mice, Nude , Female , Male
6.
Front Immunol ; 15: 1397541, 2024.
Article in English | MEDLINE | ID: mdl-38774870

ABSTRACT

Aim: Despite the significant therapeutic outcomes achieved in systemic treatments for liver hepatocellular carcinoma (LIHC), it is an objective reality that only a low proportion of patients exhibit an improved objective response rate (ORR) to current immunotherapies. Antibody-dependent cellular phagocytosis (ADCP) immunotherapy is considered the new engine for precision immunotherapy. Based on this, we aim to develop an ADCP-based LIHC risk stratification system and screen for relevant targets. Method: Utilizing a combination of single-cell RNA sequencing (scRNA-seq) and bulk RNA-seq data, we screened for ADCP modulating factors in LIHC and identified differentially expressed genes along with their involved functional pathways. A risk scoring model was established by identifying ADCP-related genes with prognostic value through LASSO Cox regression analysis. The risk scoring model was then subjected to evaluations of immune infiltration and immunotherapy relevance, with pan-cancer analysis and in vitro experimental studies conducted on key targets. Results: Building on the research by Kamber RA et al., we identified GYPA, CLDN18, and IRX5 as potential key target genes regulating ADCP in LIHC. These genes demonstrated significant correlations with immune infiltration cells, such as M1-type macrophages, and the effectiveness of immunotherapy in LIHC, as well as a close association with clinical pathological staging and patient prognosis. Pan-cancer analysis revealed that CLDN18 was prognostically and immunologically relevant across multiple types of cancer. Validation through tissue and cell samples confirmed that GYPA and CLDN18 were upregulated in liver cancer tissues and cells. Furthermore, in vitro knockdown of CLDN18 inhibited the malignancy capabilities of liver cancer cells. Conclusion: We have identified an ADCP signature in LIHC comprising three genes. Analysis based on a risk scoring model derived from these three genes, coupled with subsequent experimental validation, confirmed the pivotal role of M1-type macrophages in ADCP within LIHC, establishing CLDN18 as a critical ADCP regulatory target in LIHC.


Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , RNA-Seq , Humans , Liver Neoplasms/genetics , Liver Neoplasms/immunology , Liver Neoplasms/therapy , Carcinoma, Hepatocellular/genetics , Carcinoma, Hepatocellular/immunology , Carcinoma, Hepatocellular/therapy , Prognosis , Immunotherapy/methods , Gene Expression Regulation, Neoplastic , Biomarkers, Tumor/genetics , Single-Cell Analysis , Phagocytosis/genetics , Tumor Microenvironment/immunology , Tumor Microenvironment/genetics , Gene Expression Profiling , Male , Claudins/genetics , Female , Single-Cell Gene Expression Analysis
7.
Sci Transl Med ; 16(748): eadl2720, 2024 May 22.
Article in English | MEDLINE | ID: mdl-38776391

ABSTRACT

We present the preclinical pharmacology of BNT142, a lipid nanoparticle (LNP)-formulated RNA (RNA-LNP) encoding a T cell-engaging bispecific antibody that monovalently binds the T cell marker CD3 and bivalently binds claudin 6 (CLDN6), an oncofetal antigen that is absent from normal adult tissue but expressed on various solid tumors. Upon BNT142 RNA-LNP delivery in cell culture, mice, and cynomolgus monkeys, RNA is translated, followed by self-assembly into and secretion of the functional bispecific antibody RiboMab02.1. In vitro, RiboMab02.1 mediated CLDN6 target cell-specific activation and proliferation of T cells, and potent target cell killing. In mice and cynomolgus monkeys, intravenously administered BNT142 RNA-LNP maintained therapeutic serum concentrations of the encoded antibody. Concentrations of RNA-encoded RiboMab02.1 were maintained longer in circulation in mice than concentrations of directly injected, sequence-identical protein. Weekly injections of mice with BNT142 RNA-LNP in the 0.1- to 1-µg dose range were sufficient to eliminate CLDN6-positive subcutaneous human xenograft tumors and increase survival over controls. Tumor regression was associated with an influx of T cells and depletion of CLDN6-positive cells. BNT142 induced only transient and low cytokine production in CLDN6-positive tumor-bearing mice humanized with peripheral blood mononuclear cells (PBMCs). No signs of adverse effects from BNT142 RNA-LNP administration were observed in mice or cynomolgus monkeys. On the basis of these and other findings, a phase 1/2 first-in-human clinical trial has been initiated to assess the safety and preliminary efficacy of BNT142 RNA-LNP in patients with CLDN6-positive advanced solid tumors (NCT05262530).


Subject(s)
Antibodies, Bispecific , Claudins , Macaca fascicularis , T-Lymphocytes , Animals , Humans , Antibodies, Bispecific/pharmacology , Antibodies, Bispecific/pharmacokinetics , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Claudins/metabolism , Mice , RNA/metabolism , Female , Cell Line, Tumor , Xenograft Model Antitumor Assays , Liposomes , Nanoparticles
8.
JCO Precis Oncol ; 8: e2300543, 2024 May.
Article in English | MEDLINE | ID: mdl-38781542

ABSTRACT

PURPOSE: Claudin 18 isoform 2 (CLDN18.2) is an emerging biomarker and therapeutic target in gastric and gastroesophageal junction (G/GEJ) adenocarcinoma. This study aimed to obtain deeper understanding of CLDN18.2 positivity patterns, prognostic implications, and associations with various demographic, clinical, and molecular characteristics in G/GEJ adenocarcinoma. METHODS: Archived tumor tissue samples from 304 patients with G/GEJ adenocarcinoma in the United States were assessed for CLDN18.2 positivity by immunohistochemistry. CLDN18.2 positivity was defined as ≥50% or ≥75% of tumor cells with CLDN18 staining intensity ≥2+. CLDN18.2 positivity patterns were analyzed for association with prognosis and clinicopathologic/demographic characteristics. Where possible, CLDN18.2 positivity was analyzed for matched tissue samples to assess concordance between primary and metastatic tumors and concordance before and after chemotherapy. RESULTS: The overall prevalence of CLDN18.2-positive tumors (with ≥75% cutoff) was 44.4% (n = 135 of 304). CLDN18.2-positive tumors had a prevalence of 51.4% (n = 91 of 177) in gastric and 34.6% (n = 44 of 127) in GEJ adenocarcinoma. With a ≥50% cutoff, the prevalence of CLDN18.2-positive tumors was 64.4% (n = 114 of 177) in gastric adenocarcinoma and 44.9% (n = 57 of 127) in GEJ adenocarcinoma. There was no association between overall survival and CLDN18.2 positivity using either threshold. Statistically significant associations were noted between CLDN18.2 positivity and sex, histologic type of G/GEJ adenocarcinoma, and adenocarcinoma subtype (≥75% cutoff), and metastasis site and tumor grade (≥50% cutoff). The overall concordance of CLDN18.2 positivity (≥75% cutoff) was 73% (27 of 37) for matched primary versus metastatic tumor samples and 74% (29 of 39) for matched samples before and after chemotherapy. CONCLUSION: This study demonstrated that CLDN18.2 positivity did not correlate with survival in G/GEJ adenocarcinoma, consistent with published data. On the basis of matched sample analysis, CLDN18.2 appears to demonstrate >70% concordance as a biomarker. Observed correlations with certain patient/tumor characteristics warrant further study.


Subject(s)
Adenocarcinoma , Claudins , Esophageal Neoplasms , Esophagogastric Junction , Stomach Neoplasms , Humans , Male , Stomach Neoplasms/pathology , Stomach Neoplasms/epidemiology , Adenocarcinoma/pathology , Female , Esophagogastric Junction/pathology , Middle Aged , Aged , Prognosis , Retrospective Studies , Esophageal Neoplasms/pathology , Protein Isoforms , Adult , Aged, 80 and over , Prevalence
9.
Int J Mol Sci ; 25(9)2024 Apr 24.
Article in English | MEDLINE | ID: mdl-38731853

ABSTRACT

Claudins are a family of 27 proteins that have an important role in the formation of tight junctions. They also have an important function in ion exchange, cell mobility, and the epithelial-to-mesenchymal transition, the latter being very important in cancer invasion and metastasis. Therapeutic targeting of claudins has been investigated to improve cancer outcomes. Recent evidence shows improved outcomes when combining monoclonal antibodies against claudin 18.2 with chemotherapy for patients with gastroesophageal junction cancer. Currently, chimeric antigen receptor T-cells targeting claudin 18 are under investigation. In this review, we will discuss the major functions of claudins, their distribution in the normal as well as cancerous tissues, and their effect in cancer metastasis, with a special focus on the therapeutic targeting of claudins to improve cancer outcomes.


Subject(s)
Claudins , Neoplasms , Humans , Claudins/metabolism , Neoplasms/drug therapy , Neoplasms/metabolism , Neoplasms/pathology , Animals , Epithelial-Mesenchymal Transition , Molecular Targeted Therapy/methods , Tight Junctions/metabolism
10.
Int J Mol Sci ; 25(9)2024 Apr 29.
Article in English | MEDLINE | ID: mdl-38732086

ABSTRACT

The ability of the immune system to combat pathogens relies on processes like antigen sampling by dendritic cells and macrophages migrating through endo- and epithelia or penetrating them with their dendrites. In addition, other immune cell subtypes also migrate through the epithelium after activation. For paracellular migration, interactions with tight junctions (TJs) are necessary, and previous studies reported TJ protein expression in several immune cells. Our investigation aimed to characterize, in more detail, the expression profiles of TJ proteins in different immune cells in both naïve and activated states. The mRNA expression analysis revealed distinct expression patterns for TJ proteins, with notable changes, mainly increases, upon activation. At the protein level, LSR appeared predominant, being constitutively present in naïve cell membranes, suggesting roles as a crucial interaction partner. Binding experiments suggested the presence of claudins in the membrane only after stimulation, and claudin-8 translocation to the membrane occurred after stimulation. Our findings suggest a dynamic TJ protein expression in immune cells, implicating diverse functions in response to stimulation, like interaction with TJ proteins or regulatory roles. While further analysis is needed to elucidate the precise roles of TJ proteins, our findings indicate important non-canonical functions of TJ proteins in immune response.


Subject(s)
Tight Junction Proteins , Tight Junctions , Tight Junction Proteins/metabolism , Tight Junction Proteins/genetics , Humans , Tight Junctions/metabolism , Dendritic Cells/metabolism , Dendritic Cells/immunology , Animals , Macrophages/metabolism , Macrophages/immunology , Claudins/metabolism , Claudins/genetics , Cell Membrane/metabolism
11.
Genes (Basel) ; 15(5)2024 May 06.
Article in English | MEDLINE | ID: mdl-38790217

ABSTRACT

Hearing impairment, a rare inherited condition, is notably prevalent in populations with high rates of consanguinity. The most common form observed globally is autosomal recessive non-syndromic hearing loss. Despite its prevalence, this genetic disorder is characterized by a substantial genetic diversity, making diagnosis and screening challenging. The emergence of advanced next-generation sequencing (NGS) technologies has significantly advanced the discovery of genes and variants linked to various conditions, such as hearing loss. In this study, our objective was to identify the specific variant causing hearing loss in a family from Syria using clinical exome sequencing. The proband in the family exhibited profound deafness as shown by pure-tone audiometry results. The analysis of the different variants obtained by NGS revealed the presence of a nonsense mutation within the CLDN14 gene. Through Sanger sequencing, we verified that this variant segregates with the disease and was not present in the control population. Moreover, we conducted a comprehensive review of all reported deafness-related CLDN14 mutations and their associated phenotypes. Furthermore, we endeavored to carry out a comparative analysis between the CLDN14 and GJB2 genes, with the objective of identifying potential factors that could explain the notable discrepancy in mutation frequency between these two genes.


Subject(s)
Claudins , Connexin 26 , Deafness , Pedigree , Phenotype , Humans , Male , Female , Connexin 26/genetics , Syria , Deafness/genetics , Claudins/genetics , Mutation , Exome Sequencing , Adult , Codon, Nonsense/genetics , Connexins/genetics
12.
Curr Opin Nephrol Hypertens ; 33(4): 433-440, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38690798

ABSTRACT

PURPOSE OF REVIEW: Activation of the calcium-sensing receptor (CASR) in the parathyroid gland suppresses the release of parathyroid hormone (PTH). Furthermore, activation of the renal CASR directly increases the urinary excretion of calcium, by inhibiting transepithelial calcium transport in the nephron. Gain-of-function mutations in the CASR gene lead to autosomal dominant hypocalcemia 1 (ADH1), with inappropriately low PTH levels and hypocalcemia, indicative of excessive activation of the parathyroid CASR. However, hypercalciuria is not always observed. The reason why the manifestation of hypercalciuria is not uniform among ADH1 patients is not well understood. RECENT FINDINGS: Direct activation of the CASR in the kidney has been cumbersome to study, and an indirect measure to effectively estimate the degree of CASR activation following chronic hypercalcemia or genetic gain-of-function CASR activation has been lacking. Studies have shown that expression of the pore-blocking claudin-14 is strongly stimulated by the CASR in a dose-dependent manner. This stimulatory effect is abolished after renal Casr ablation in hypercalcemic mice, suggesting that claudin-14 abundance may gauge renal CASR activation. Using this marker has led to unexpected discoveries regarding renal CASR activation. SUMMARY: These new studies have informed on renal CASR activation thresholds and the downstream CASR-regulated calcium transport mechanisms.


Subject(s)
Kidney , Receptors, Calcium-Sensing , Receptors, Calcium-Sensing/metabolism , Receptors, Calcium-Sensing/genetics , Humans , Animals , Kidney/metabolism , Hypercalciuria/metabolism , Hypercalciuria/genetics , Calcium/metabolism , Hypercalcemia/metabolism , Hypercalcemia/genetics , Claudins/metabolism , Claudins/genetics , Hypocalcemia , Hypoparathyroidism/congenital
13.
Cell Death Dis ; 15(4): 284, 2024 Apr 23.
Article in English | MEDLINE | ID: mdl-38654000

ABSTRACT

Intestinal stem cells (ISCs) play a crucial role in the continuous self-renewal and recovery of the intestinal epithelium. In previous studies, we have revealed that the specific absence of Claudin-7 (Cldn-7) in intestinal epithelial cells (IECs) can lead to the development of spontaneous colitis. However, the mechanisms by which Cldn-7 maintains homeostasis in the colonic epithelium remain unclear. Therefore, in the present study, we used IEC- and ISC-specific Cldn-7 knockout mice to investigate the regulatory effects of Cldn-7 on colonic Lgr5+ stem cells in the mediation of colonic epithelial injury and repair under physiological and inflammatory conditions. Notably, our findings reveal that Cldn-7 deletion disrupts the self-renewal and differentiation of colonic stem cells alongside the formation of colonic organoids in vitro. Additionally, these Cldn-7 knockout models exhibited heightened susceptibility to experimental colitis, limited epithelial repair and regeneration, and increased differentiation toward the secretory lineage. Mechanistically, we also established that Cldn-7 facilitates the proliferation, differentiation, and organoid formation of Lgr5+ stem cells through the maintenance of Wnt and Notch signalling pathways in the colonic epithelium. Overall, our study provides new insights into the maintenance of ISC function and colonic epithelial homoeostasis.


Subject(s)
Claudins , Homeostasis , Receptors, Notch , Stem Cells , Wnt Signaling Pathway , Animals , Mice , Cell Differentiation , Cell Proliferation , Claudins/metabolism , Claudins/genetics , Colitis/metabolism , Colitis/pathology , Colitis/chemically induced , Colon/metabolism , Intestinal Mucosa/metabolism , Mice, Knockout , Organoids/metabolism , Receptors, G-Protein-Coupled/metabolism , Receptors, G-Protein-Coupled/genetics , Receptors, Notch/metabolism , Stem Cells/metabolism , Stem Cells/cytology
14.
Int J Mol Sci ; 25(7)2024 Apr 03.
Article in English | MEDLINE | ID: mdl-38612818

ABSTRACT

Many genomic, anatomical and functional differences exist between the medullary (MTAL) and the cortical thick ascending limb of the loop of Henle (CTAL), including a higher expression of claudin-10 (CLDN10) in the MTAL than in the CTAL. Therefore, we assessed to what extent the Cldn10 gene expression is a determinant of differential gene expression between MTAL and CTAL. RNAs extracted from CTAL and MTAL microdissected from wild type (WT) and Cldn10 knock out mice (cKO) were analyzed by RNAseq. Differential and enrichment analyses (GSEA) were performed with interactive R Shiny software. Between WT and cKO MTAL, 637 genes were differentially expressed, whereas only 76 were differentially expressed between WT and cKO CTAL. Gene expression patterns and GSEA analyses in all replicates showed that WT MTAL did not cluster with the other replicates; no hierarchical clustering could be found between WT CTAL, cKO CTAL and cKO MTAL. Compared to WT replicates, cKO replicates were enriched in Cldn16, Cldn19, Pth1r, (parathyroid hormone receptor type 1), Casr (calcium sensing receptor) and Vdr (Vitamin D Receptor) mRNA in both the cortex and medulla. Cldn10 is associated with gene expression patterns, including genes specifically involved in divalent cations reabsorption in the TAL.


Subject(s)
Adrenal Medulla , Extremities , Animals , Mice , Claudins/genetics , Mice, Knockout , Gene Expression
15.
Ann N Y Acad Sci ; 1535(1): 92-108, 2024 May.
Article in English | MEDLINE | ID: mdl-38598500

ABSTRACT

The tight junction protein claudin-7 is essential for tight junction function and intestinal homeostasis. Cldn7 deletion in mice leads to an inflammatory bowel disease-like phenotype exhibiting severe intestinal epithelial damage, weight loss, inflammation, mucosal ulcerations, and epithelial hyperplasia. Claudin-7 has also been shown to be involved in cancer metastasis and invasion. Here, we test our hypothesis that claudin-7 plays an important role in regulating colonic intestinal stem cell function. Conditional knockout of Cldn7 in the colon led to impaired epithelial cell differentiation, hyperproliferative epithelium, a decrease in active stem cells, and dramatically altered gene expression profiles. In 3D colonoid culture, claudin-7-deficient crypts were unable to survive and form spheroids, emphasizing the importance of claudin-7 in stem cell survival. Inhibition of the Hippo pathway or activation of Notch signaling partially rescued the defective stem cell behavior. Concurrent Notch activation and Hippo inhibition resulted in restored colonoid survival, growth, and differentiation to the level comparable to those of wild-type derived crypts. In this study, we highlight the essential role of claudin-7 in regulating Notch and Hippo signaling-dependent colonic stem cell functions, including survival, self-renewal, and differentiation. These new findings may shed light on potential avenues to explore for drug development in colorectal cancer.


Subject(s)
Claudins , Colon , Hippo Signaling Pathway , Receptors, Notch , Signal Transduction , Stem Cells , Animals , Claudins/metabolism , Claudins/genetics , Receptors, Notch/metabolism , Mice , Stem Cells/metabolism , Colon/metabolism , Colon/pathology , Protein Serine-Threonine Kinases/metabolism , Protein Serine-Threonine Kinases/genetics , Mice, Knockout , Intestinal Mucosa/metabolism , Cell Differentiation/physiology , Tight Junctions/metabolism
16.
Int J Mol Sci ; 25(7)2024 Mar 25.
Article in English | MEDLINE | ID: mdl-38612449

ABSTRACT

Stress granules (SGs) are membraneless ribonucleoprotein (RNP)-based cellular foci formed in response to stress, facilitating cell survival by protecting against damage. Mammalian spermatogenesis should be maintained below body temperature for proper development, indicating its vulnerability to heat stress (HS). In this study, biotin tracer permeability assays showed that the inhibition of heat-induced SG assembly in the testis by 4-8 mg/kg cycloheximide significantly increased the percentage of seminiferous tubules with a damaged blood-testis barrier (BTB). Western blot results additionally revealed that the suppression of heat-induced SG assembly in Sertoli cell line, TM4 cells, by RNA inference of G3bp1/2 aggravated the decline in the BTB-related proteins ZO-1, ß-Catenin and Claudin-11, indicating that SGs could protect the BTB against damage caused by HS. The protein components that associate with SGs in Sertoli cells were isolated by sequential centrifugation and immunoprecipitation, and were identified by liquid chromatography with tandem mass spectrometry. Gene Ontology and KEGG pathway enrichment analysis revealed that their corresponding genes were mainly involved in pathways related to proteasomes, nucleotide excision repair, mismatch repair, and DNA replication. Furthermore, a new SG component, the ubiquitin associated protein 2 (UBAP2), was found to translocate to SGs upon HS in TM4 cells by immunofluorescence. Moreover, SG assembly was significantly diminished after UBAP2 knockdown by RNA inference during HS, suggesting the important role of UBAP2 in SG assembly. In addition, UBAP2 knockdown reduced the expression of ZO-1, ß-Catenin and Claudin-11, which implied its potential role in the function of the BTB. Overall, our study demonstrated the role of SGs in maintaining BTB functions during HS and identified a new component implicated in SG formation in Sertoli cells. These findings not only offer novel insights into the biological functions of SGs and the molecular mechanism of low fertility in males in summer, but also potentially provide an experimental basis for male fertility therapies.


Subject(s)
Blood-Testis Barrier , DNA Helicases , Male , Animals , Mice , Poly-ADP-Ribose Binding Proteins , RNA Helicases , RNA Recognition Motif Proteins , Stress Granules , beta Catenin , RNA , Claudins , Mammals
17.
BMC Complement Med Ther ; 24(1): 145, 2024 Apr 04.
Article in English | MEDLINE | ID: mdl-38575994

ABSTRACT

BACKGROUND: Ginger is a common aromatic vegetable with a wide range of functional ingredients and considerable medicinal and nutritional properties. Numerous studies have shown that ginger and its active ingredients have suppressive effects on manifold tumours, including ovarian cancer (OC). However, the molecular mechanism by which ginger inhibits OC is not clear. The aim of this study was to investigate the function and mechanism of ginger in OC. METHODS: The estimation of n6-methyladenosine (m6A) levels was performed using the m6A RNA Methylation Quantification Kit, and RT-qPCR was used to determine the expression of m6A-related genes and proteins. The m6A methylationome was detected by MeRIP-seq, following analysis of the data. Differential methylation of genes was assessed utilizing RT-qPCR and Western Blotting. The effect of ginger on SKOV3 invasion in ovarian cancer cells was investigated using the wound healing assay and transwell assays. RESULTS: Ginger significantly reduced the m6A level of OC cells SKOV3. The 3'UTR region is the major site of modification for m6A methylation, and its key molecular activities include Cell Adhesion Molecules, according to meRIP-seq results. Moreover, it was observed that Ginger aids significantly in downregulating the CLDN7, CLDN11 mRNA, and protein expression. The results of wound healing assay and transwell assay showed that ginger significantly inhibited the invasion of OC cells SKOV3. CONCLUSIONS: Ginger inhibits ovarian cancer cells' SKOV3 invasion by regulating m6A methylation through CLDN7, CLDN11, and CD274.


Subject(s)
Ovarian Neoplasms , Zingiber officinale , Female , Humans , Ovarian Neoplasms/drug therapy , Ovarian Neoplasms/genetics , RNA Methylation , B7-H1 Antigen , Claudins
18.
Int J Biol Sci ; 20(5): 1578-1601, 2024.
Article in English | MEDLINE | ID: mdl-38481806

ABSTRACT

Background: The application of chimeric antigen receptor (CAR) NK cells in solid tumors is hindered by lack of tumor-specific targets and inefficient CAR-NK cell efficacy. Claudin-6 (CLDN6) has been reported to be overexpressed in ovarian cancer and may be an attractive target for CAR-NK cells immunotherapy. However, the feasibility of using anti-CLDN6 CAR-NK cells to treat ovarian cancer remains to be explored. Methods: CLDN6 expression in primary human ovarian cancer, normal tissues and cell lines were detected by immunohistochemistry and western blot. Two types of third-generation CAR NK-92MI cells targeting CLDN6, CLDN6-CAR1 NK-92MI cells with domains containing self-activated elements (NKG2D, 2B4) and CLDN6-CAR2 NK-92MI cells with classical domains (CD28, 4-1BB) were constructed by lentivirus transfection, sorted by flow cytometry and verified by western blot and qPCR. OVCAR-3, SK-OV-3, A2780, Hey and PC-3 cells expressing the GFP and luciferase genes were transduced. Subcutaneous and intraperitoneal tumor models were established via NSG mice. The ability of CLDN6-CAR NK cells to kill CLDN6-positive ovarian cancer cells were evaluated in vitro and in vivo by live cell imaging and bioluminescence imaging. Results: Both CLDN6-CAR1 and CLDN6-CAR2 NK-92MI cells could specifically killed CLDN6-positive ovarian cancer cells (OVCAR-3, SK-OV-3, A2780 and Hey), rather than CLDN6 negative cell (PC-3), in vitro. CLDN6-CAR1 NK-92MI cells with domains containing self-activated elements (NKG2D, 2B4) exhibited stronger cytotoxicity than CLDN6-CAR2 NK-92MI cells with classical domains (CD28, 4-1BB). Furthermore, CLDN6-CAR1 NK cells could effectively eliminate ovarian cancer cells in subcutaneous and intraperitoneal tumor models. More importantly, CAR-NK cells combined with immune checkpoint inhibitors, anti-PD-L1, could synergistically enhance the antitumor efficacy of CLDN6-targeted CAR-NK cells. Conclusions: These results indicate that CLDN6-CAR NK cells possess strong antitumor activity and represent a promising immunotherapeutic modality for ovarian cancer.


Subject(s)
Claudins , Ovarian Neoplasms , Receptors, Chimeric Antigen , Humans , Animals , Mice , Female , Receptors, Chimeric Antigen/genetics , Ovarian Neoplasms/therapy , Ovarian Neoplasms/metabolism , Cell Line, Tumor , Apoptosis , NK Cell Lectin-Like Receptor Subfamily K/metabolism , CD28 Antigens/metabolism , Killer Cells, Natural , Immunotherapy/methods , Immunotherapy, Adoptive/methods
19.
J Biochem Mol Toxicol ; 38(3): e23682, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38462752

ABSTRACT

Claudin-6 (CLDN6) has been extensively studied in different tumors to date. However, in the case of nonsmall cell lung cancer (NSCLC), CLDN6 has a largely unknown role and molecular mechanism. We detected the expression of CLDN6 in NSCLC tissues and cells using reverse transcription-quantitative polymerase chain reaction (PCR) and western blot assays. A gain-of-function experiment was performed to evaluate the biological effects of CLDN6 on NSCLC cell behaviors. Methylation-specific PCR was utilized to detect the DNA methylation of CLDN6 gene promoter region. The interaction of CLDN6 and receptor interacting protein 1 (RIP1) was determined by coimmunoprecipitation assay. Furthermore, the modulation of CLDN6 on RIP1/apoptosis signal-regulating kinase 1 (ASK1)/c-Jun N-terminal kinase (JNK) axis was confirmed. The results showed that in NSCLC tissues and cells, CLDN6 expression level was declined, and was associated with a high level of DNA methylation. CLDN6 overexpression suppressed the viability, invasion, migration, and promoted cell apoptosis. Besides, the enhanced expression of CLDN6 reduced the glycolysis and the dysfunction of mitochondrial respiration of NSCLC cells. Mechanistic investigation confirmed that CLDN6 interacted with RIP1 and inhibited cellular biological function of NSCLC cells via RIP1/ASK1/JNK axis. Besides, CLDN6 overexpression inhibited tumor growth in vivo. In conclusion, CLDN6 inhibited NSCLC cell proliferation through inactivating aerobic glycolysis via the RIP1/ASK1/JNK axis.


Subject(s)
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Humans , Carcinoma, Non-Small-Cell Lung/metabolism , Lung Neoplasms/metabolism , MAP Kinase Kinase Kinase 5/pharmacology , Claudins/genetics , Claudins/metabolism , Cell Line, Tumor , Apoptosis , Cell Proliferation
20.
J Nanobiotechnology ; 22(1): 104, 2024 Mar 11.
Article in English | MEDLINE | ID: mdl-38468289

ABSTRACT

Modulating macrophages presents a promising avenue in tumor immunotherapy. However, tumor cells have evolved mechanisms to evade macrophage activation and phagocytosis. Herein, we introduced a bispecific antibody-based nanoengager to facilitate the recognition and phagocytosis of tumor cells by macrophages. Specifically, we genetically engineered two single chain variable fragments (scFv) onto cell membrane: anti-CD40 scFv for engaging with macrophages and anti-Claudin18.2 (CLDN18.2) scFv for interacting with tumor cells. These nanoengagers were further constructed by coating scFv-anchored membrane into PLGA nanoparticle core. Our developed nanoengagers significantly boosted immune responses, including increased recognition and phagocytosis of tumor cells by macrophages, enhanced activation and antigen presentation, and elevated cytotoxic T lymphocyte activity. These combined benefits resulted in enhancing antitumor efficacy against highly aggressive "cold" pancreatic cancer. Overall, this study offers a versatile nanoengager design for immunotherapy, achieved through genetically engineering to incorporate antibody-anchored membrane.


Subject(s)
Antibodies, Bispecific , Neoplasms , Pancreatic Neoplasms , Humans , Pancreatic Neoplasms/therapy , Immunotherapy/methods , Genetic Engineering , T-Lymphocytes, Cytotoxic , Claudins
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