ABSTRACT
TGF-ß1 plays a pivotal role in the metastatic cascade of malignant neoplasms. N6-methyladenosine (m6A) stands as one of the most abundant modifications on the mRNA transcriptome. However, in the metastasis of gallbladder carcinoma (GBC), the effect of TGF-ß1 with mRNA m6A modification, especially the effect of mRNA translation efficiency associated with m6A modification, remains poorly elucidated. Here we demonstrated a negative correlation between FOXA1 and TGF-ß1 expression in GBC. Overexpression of FOXA1 inhibited TGF-ß1-induced migration and epithelial-mesenchymal transition (EMT) in GBC cells. Mechanistically, we confirmed that TGF-ß1 suppressed the translation efficiency of FOXA1 mRNA through polysome profiling analysis. Importantly, both in vivo and in vitro experiments showed that TGF-ß1 promoted m6A modification on the coding sequence (CDS) region of FOXA1 mRNA, which was responsible for the inhibition of FOXA1 mRNA translation by TGF-ß1. We demonstrated through MeRIP and RIP assays, dual-luciferase reporter assays and site-directed mutagenesis that ALKBH5 promoted FOXA1 protein expression by inhibiting m6A modification on the CDS region of FOXA1 mRNA. Moreover, TGF-ß1 inhibited the binding capacity of ALKBH5 to the FOXA1 CDS region. Lastly, our study confirmed that overexpression of FOXA1 suppressed lung metastasis and EMT in a nude mice lung metastasis model. In summary, our research findings underscore the role of TGF-ß1 in regulating TGF-ß1/FOXA1-induced GBC EMT and metastasis by inhibiting FOXA1 translation efficiency through m6A modification.
Subject(s)
Adenosine , Epithelial-Mesenchymal Transition , Gallbladder Neoplasms , Hepatocyte Nuclear Factor 3-alpha , Mice, Nude , Protein Biosynthesis , Transforming Growth Factor beta1 , Hepatocyte Nuclear Factor 3-alpha/metabolism , Hepatocyte Nuclear Factor 3-alpha/genetics , Humans , Transforming Growth Factor beta1/metabolism , Gallbladder Neoplasms/pathology , Gallbladder Neoplasms/genetics , Gallbladder Neoplasms/metabolism , Animals , Epithelial-Mesenchymal Transition/genetics , Cell Line, Tumor , Adenosine/analogs & derivatives , Adenosine/metabolism , Mice , Neoplasm Metastasis , Gene Expression Regulation, Neoplastic , Cell Movement , RNA, Messenger/metabolism , RNA, Messenger/genetics , Mice, Inbred BALB C , MaleABSTRACT
The aim of this investigation was to evaluate the differential expression of the sterol O-acyltransferase 1 (SOAT1) protein in gallbladder cancer tissues and cells, investigate the impact of Avastin on the proliferation, migration, invasion capabilities of gallbladder cancer cells, and its potential to induce cell apoptosis. Immunohistochemical analysis of samples from 145 gallbladder cancer patients was conducted, along with analysis of SOAT1 protein, mRNA expression levels, and cholesterol content in gallbladder cancer cell lines SGC-996, NOZ, and gallbladder cancer (GBC)-SD using Western blot and q-PCR techniques. Furthermore, the effects of Avastin on the proliferation, migration, and invasion capabilities of these gallbladder cancer cell lines were studied, and its ability to induce cell apoptosis was evaluated using flow cytometry, Western blot, and immunohistochemical methods. Additionally, gene expression and pathway analysis were performed, and the synergistic therapeutic effects of Avastin combined with gemcitabine were tested in a gallbladder cancer xenograft model. The study found that SOAT1 expression was significantly upregulated in GBC tissues and positively correlated with lymph node metastasis and TNM staging. In vitro experiments demonstrated that Avastin significantly inhibited the proliferation, migration, and invasion capabilities of SGC-996 and GBC-SD cell lines and induced apoptosis. RNA sequencing analysis revealed multiple differentially expressed genes in cells treated with Avastin, primarily enriched in biological pathways such as signaling transduction, malignant tumors, and the immune system. In vivo, experiments confirmed that Avastin could effectively suppress tumor growth in a gallbladder cancer xenograft model and enhanced the treatment efficacy when used in combination with gemcitabine. Overall, these findings provide new insights and strategies for targeted therapy in gallbladder cancer.
Subject(s)
Gallbladder Neoplasms , Sterol O-Acyltransferase , Aged , Animals , Female , Humans , Male , Mice , Middle Aged , Antibodies, Monoclonal, Humanized/pharmacology , Antibodies, Monoclonal, Humanized/therapeutic use , Apoptosis/drug effects , Cell Line, Tumor , Cell Movement/drug effects , Cell Proliferation/drug effects , Gallbladder Neoplasms/pathology , Gallbladder Neoplasms/drug therapy , Gallbladder Neoplasms/metabolism , Gallbladder Neoplasms/genetics , Gene Expression Regulation, Neoplastic/drug effects , Neoplasm Proteins/metabolism , Neoplasm Proteins/genetics , Sterol O-Acyltransferase/metabolism , Sterol O-Acyltransferase/genetics , Xenograft Model Antitumor AssaysABSTRACT
BACKGROUND: Gallbladder cancer (GBC), a highly malignant gastrointestinal tumor, lacks effective therapies. Foxhead box A2 (FOXA2) is a tumor suppressor that is poorly expressed in various human malignancies. This study aimed to ascertain FOXA2 expression in GBC and its relevance to tumor metastasis, and to elucidate its regulatory mechanism with epithelial-mesenchymal transition (EMT) as an entry point, in the hope of providing a potential therapeutic target for GBC. METHODS: FOXA2 expression in GBC tissues was first detected using immunohistochemistry (IHC), followed by correlation analysis with clinicopathological characteristics and survival prognosis. Subsequently, the effects of FOXA2 on GBC cell migration and invasion, as well as EMT induction, were evaluated by scratch, Transwell, RT-PCR, and Western blot assays, together with animal experimentation. Ultimately, mRNA sequencing was carried out to identify the key downstream target genes of FOXA2 in controlling the EMT process in GBC cells, and dual-luciferase reporter and chromatin immunoprecipitation assays were used to determine its regulatory mechanism. RESULTS: FOXA2 was underexpressed in GBC tissues and inversely correlated with tumor node metastasis stage, lymph node metastasis, and poor patient prognosis. FOXA2 exerts suppressive effects on EMT and metastasis of GBC in vivo and in vitro. FOXA2 can impede GBC cell migratory and invasive functions and EMT by positively mediating serine protein kinase inhibitor B5 (SERPINB5) expression. CONCLUSION: FOXA2 directly binds to the SERPINB5 promoter region to stimulate its transcription, thereby modulating the migration and invasion behaviors of GBC cells as well as the EMT process, which might be an effective therapeutic target against GBC.
Subject(s)
Gallbladder Neoplasms , Animals , Humans , Cell Line, Tumor , Cell Movement/genetics , Cell Proliferation , Epithelial-Mesenchymal Transition/genetics , Gallbladder Neoplasms/genetics , Gallbladder Neoplasms/pathology , Gene Expression Regulation, Neoplastic , Hepatocyte Nuclear Factor 3-beta/genetics , Hepatocyte Nuclear Factor 3-beta/metabolismABSTRACT
Introduction: Gallbladder cancer (GBC) is a highly malignant biliary tumor with a poor prognosis. As existing therapies for advanced metastatic GBC are rarely effective, there is an urgent need to identify more effective targets for treatment. Methods: Hub genes of GBC were identified by bioinformatics analysis and their expression in GBC was analyzed by tissue validation. The biological role of CEP55 in GBC cell and the underlying mechanism of the anticancer effect of CEP55 knockdown were evaluated via CCK8, colony formation assay, EDU staining, flow cytometry, western blot, immunofluorescence, and an alkaline comet assay. Results: We screened out five hub genes of GBC, namely PLK1, CEP55, FANCI, NEK2 and PTTG1. CEP55 is not only overexpressed in the GBC but also correlated with advanced TNM stage, differentiation grade and poorer survival. After CEP55 knockdown, the proliferation of GBC cells was inhibited with cell cycle arrest in G2/M phase and DNA damage. There was a marked increase in the apoptosis of GBC cells in the siCEP55 group. Besides, in vivo, CEP55 inhibition attenuated the growth and promoted apoptosis of GBC cells. Mechanically, the tumor suppressor effect of CEP55 knockdown is associated with dysregulation of the AKT and ERK signaling networks. Discussion: These data not only demonstrate that CEP55 is identified as a potential independent predictor crucial to the diagnosis and prognosis of gallbladder cancer but also reveal the possibility for CEP55 to be used as a promising target in the treatment of GBC.