Increasing evidence suggests that FBXW7 has a high frequency of mutations in esophageal squamous cell carcinoma (ESCC). However, the function of FBXW7, especially the mutations, is not clear. This study was designed to investigate the functional significance of FBXW7 loss of function and underlying mechanism in ESCC.Immunofluorescence was applied to clarify the localization and main isoform of FBXW7 in ESCC cells. Sanger sequencing were performed to explore mutations of FBXW7 in ESCC tissues. Proliferation, colony, invasion and migration assays were performed to examine the functional roles of FBXW7 in ESCC cells in vitro and in vivo. Real-time RT-PCR, immunoblotting, GST-pulldown, LC-MS/MS and co-immunoprecipitation assay were used to explore the molecular mechanism underlying the actions of FBXW7 functional inactivation in ESCC cells. Immunohistochemical staining were used to explore the expression of FBXW7 and MAP4 in ESCC tissues.The main FBXW7 isoform in ESCC cells was the β transcript in the cytoplasm. Functional inactivation of FBXW7 led to activation of the MAPK signaling pathway and upregulation of the downstream MMP3 and VEGFA, which enhanced tumor proliferation cell invasion and migration. Among the five mutation forms screened, S327X (X means truncated mutation) had an effect similar to the FBXW7 deficiency and led to the inactivation of FBXW7 in ESCC cells. Three other point mutations, S382F, D400N and R425C, attenuated but did not eliminate FBXW7 function. The other truncating mutation, S598X, which was located outside of the WD40 domain, revealed a tiny attenuation of FBXW7 in ESCC cells. Notably, MAP4 was identified as a potential target of FBXW7. The threonine T521 of MAP4, which was phosphorylated by CHEK1, played a key role in the FBXW7-related degradation system. Immunohistochemical staining indicated that FBXW7 loss of function was associated with tumor stage and shorter survival of patients with ESCC. Univariate and multivariate Cox proportional hazards regression analyses showed that high FBXW7 and low MAP4 was an independent prognostic indicator and prospective longer survival. Moreover, a combination regimen that included MK-8353 to inhibit the phosphorylation of ERK and bevacizumab to inhibit VEGFA produced potent inhibitory effects on the growth of FBXW7 inactivation xenograft tumors in vivo.This study provided evidence that FBXW7 loss of function promoted ESCC via MAP4 overexpression and ERK phosphorylation, and this novel FBXW7/MAP4/ERK axis may be an efficient target for ESCC treatment.
Objective:To evaluate the antibacterial efficiency of the extracts from an experimental rasin-based adhesive incorporating quaternary ammonium salt monomer on streptococcus mutants.Methods:The extracts from experimental adhesive samples with different concentrations of antibacterial monomer were prepared,and densitometry was used to compare the antibacterial activity of the extracts in different groups to streptococcus mutants.Results:Δphotodensity of the extracts from all groups was not significantly different after treatment for 1 h,1 w and 1 month.Furthermore,it also had no significant differences at same time points among different groups.Conclusion:The extracts from experimental adhesive samples appear to have no influence on the growth of streptococcus mutants after treatment for 1 h,1 w and 1 month,which illustrates that the antibacterial ingredient does not leach out from experimental adhesive samples.
Objective: The majority of oral cancer is caused by malignant transformation of squamous cells in surface of the oral mucosa. However, the relationship between CEACAM1 and oral cancer is unclear. Methods: GSE23558 and GSE25099 profiles were downloaded from gene expression omnibus (GEO). Differentially expressed genes (DEGs) were screened and weighted gene co-expression network analysis (WGCNA) was performed. Construction and analysis of protein-protein interaction (PPI) Network. Gene Ontology (GO) and Kyoto Encyclopedia of Gene and Genome (KEGG), gene set enrichment analysis (GSEA), gene expression heatmap, immune infiltration analysis, comparative toxicogenomics database (CTD) were performed. TargetScan screened miRNAs that regulated central DEGs. Western blotting (WB) experiment was performed. Results: 1269 DEGs were identified. According to GO analysis, they were mainly enriched in same protein binding, signal receptor binding, cell surface, epithelial cell development. KEGG analysis showed that they were mainly enriched in cancer pathways, PI3K Akt signaling pathway, TNF signaling pathway, NF kappa B signaling pathway, TGF beta signaling pathway. PPI network showed that 11 genes (CDCA8, CCNA2, MELK, KIF2C, CDC45, HMMR, TPX2, CENPF, CDK1, CEP55, CEACAM1) were obtained. Gene expression heatmap showed that CEP55 and MELK were highly expressed in oral cancer samples. CEACAM1 was lowly expressed in oral cancer samples. CEACAM1, CEP55 and MELK were involved in tumor, inflammation, necrosis, and proliferation. Western blotting (WB) showed that CEACAM1 in oral cancer samples was lower than that in normal samples, after CEACAM1 knockdown, it was lower than that in oral cancer samples. Conclusion: CEACAM1 is lowly expressed in oral cancer, the lower CEACAM1, the worse prognosis.
Abstract Although obesity is one of the strongest risk factors for esophageal adenocarcinoma, the molecular mechanisms underlying this association remain unclear. We recently identified four esophageal adenocarcinoma–specific master regulator transcription factors (MRTF) ELF3, KLF5, GATA6, and EHF. In this study, gene-set enrichment analysis of both esophageal adenocarcinoma patient samples and cell line models unbiasedly underscores fatty acid synthesis as the central pathway downstream of three MRTFs (ELF3, KLF5, GATA6). Further characterizations unexpectedly identified a transcriptional feedback loop between MRTF and fatty acid synthesis, which mutually activated each other through the nuclear receptor, PPARG. MRTFs cooperatively promoted PPARG transcription by directly regulating its promoter and a distal esophageal adenocarcinoma–specific enhancer, leading to PPARG overexpression in esophageal adenocarcinoma. PPARG was also elevated in Barrett’s esophagus, a recognized precursor to esophageal adenocarcinoma, implying that PPARG might play a role in the intestinal metaplasia of esophageal squamous epithelium. Upregulation of PPARG increased de novo synthesis of fatty acids, phospholipids, and sphingolipids as revealed by mass spectrometry–based lipidomics. Moreover, ChIP-seq, 4C-seq, and a high-fat diet murine model together characterized a novel, noncanonical, and cancer-specific function of PPARG in esophageal adenocarcinoma. PPARG directly regulated the ELF3 super-enhancer, subsequently activating the transcription of other MRTFs through an interconnected regulatory circuitry. Together, elucidation of this novel transcriptional feedback loop of MRTF/PPARG/fatty acid synthesis advances our understanding of the mechanistic foundation for epigenomic dysregulation and metabolic alterations in esophageal adenocarcinoma. More importantly, this work identifies a potential avenue for prevention and early intervention of esophageal adenocarcinoma by blocking this feedback loop. Significance: These findings elucidate a transcriptional feedback loop linking epigenomic dysregulation and metabolic alterations in esophageal adenocarcinoma, indicating that blocking this feedback loop could be a potential therapeutic strategy in high-risk individuals.
<div>Abstract<p>Although obesity is one of the strongest risk factors for esophageal adenocarcinoma, the molecular mechanisms underlying this association remain unclear. We recently identified four esophageal adenocarcinoma–specific master regulator transcription factors (MRTF) ELF3, KLF5, GATA6, and EHF. In this study, gene-set enrichment analysis of both esophageal adenocarcinoma patient samples and cell line models unbiasedly underscores fatty acid synthesis as the central pathway downstream of three MRTFs (ELF3, KLF5, GATA6). Further characterizations unexpectedly identified a transcriptional feedback loop between MRTF and fatty acid synthesis, which mutually activated each other through the nuclear receptor, PPARG. MRTFs cooperatively promoted PPARG transcription by directly regulating its promoter and a distal esophageal adenocarcinoma–specific enhancer, leading to PPARG overexpression in esophageal adenocarcinoma. PPARG was also elevated in Barrett’s esophagus, a recognized precursor to esophageal adenocarcinoma, implying that PPARG might play a role in the intestinal metaplasia of esophageal squamous epithelium. Upregulation of PPARG increased <i>de novo</i> synthesis of fatty acids, phospholipids, and sphingolipids as revealed by mass spectrometry–based lipidomics. Moreover, ChIP-seq, 4C-seq, and a high-fat diet murine model together characterized a novel, noncanonical, and cancer-specific function of PPARG in esophageal adenocarcinoma. PPARG directly regulated the ELF3 super-enhancer, subsequently activating the transcription of other MRTFs through an interconnected regulatory circuitry. Together, elucidation of this novel transcriptional feedback loop of MRTF/PPARG/fatty acid synthesis advances our understanding of the mechanistic foundation for epigenomic dysregulation and metabolic alterations in esophageal adenocarcinoma. More importantly, this work identifies a potential avenue for prevention and early intervention of esophageal adenocarcinoma by blocking this feedback loop.</p>Significance:<p>These findings elucidate a transcriptional feedback loop linking epigenomic dysregulation and metabolic alterations in esophageal adenocarcinoma, indicating that blocking this feedback loop could be a potential therapeutic strategy in high-risk individuals.</p></div>
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