Project description:The high recurrence rate and poor survival prospects of esophageal squamous cell carcinoma (ESCC) patients after treatment make the ongoing research on chemoprevention drugs for ESCC particularly important. In helping to solve this problem, we screened a large number of FDA-approved drugs and found that levodopa, a drug used to treat Parkinson’s disease, has an inhibitory effect on the growth of ESCC cells. To elucidate the molecular mechanisms, we applied mass spectrometry to investigate the anti-tumor activity of levodopa on ESCC. The results suggest that levodopa can down-regulate oxidative phosphorylation, non-alcoholic fatty liver disease (NAFLD) and parkinson disease pathways. SDHD, NDUFS4 and MT-CO3, major respiratory compounds in the mitochondria, were involved in these pathways. Down-regulation of these proteins is associated with mitochondrial dysfunction. Western blotting and immunofluorescence results confirmed the authenticity of proteomics data. Cell viability assay revealed that mitochondrial activity had been suppressed after levodopa treatment. Mitochondrial membrane potential reduction was detected by JC-1 and TMRE assays. And transmission electron microscope (TEM) analysis indicated that mitochondrial morphology changed. Taken together, levodopa inhibits the growth of ESCC through restraining the mitochondria.
Project description:Background: Esophageal squamous cell carcinoma (ESCC) is a common invasive malignancy worldwide with poor clinical outcomes. Increasing amount of long non-coding RNAs (lncRNAs) have been reported to be involved in cancer development. However, lncRNAs that are functional in ESCC and the underlying molecular mechanisms remain largely unknown. Methods: Transcriptomic analysis was performed to identify dysregulated lncRNAs in ESCC tissue samples. The high expression of LINC00680 in ESCC was validated by RT-qPCR, and the oncogenic functions of LINC00680 was investigated by cell proliferation, colony formation, migration and invasion assays in ESCC cells in vitro and xenografts derived from ESCC cells in mice. RNA-seq, competitive endogenous RNA (ceRNA) network analysis, and luciferase reporter assays were carried out to identify LINC00680 target genes and the microRNAs (miRNAs) bound to LINC00680. Antisense oligonucleotides (ASOs) were used for in vivo treatment. Results: Transcriptome profiling revealed that a large number of lncRNAs was dysregulated in ESCC tissues. Notably, LINC00680 was highly expressed, and upregulation of LINC00680 was associated with large tumor size, advanced tumor stage, and poor prognosis. Functionally, knockdown of LINC00680 restrained ESCC cell proliferation, colony formation, migration, and invasion in vitro and inhibited tumor growth in vivo. Mechanistically, LINC00680 was found to act as a ceRNA by sponging miR-423-5p to regulate PAK6 (p21-activated kinase 6) expression in ESCC cells. The cell viability and motility inhibition induced by LINC00680 knockdown was significantly reversed upon PAK6 restoration and miR-423-5p inhibition. Furthermore, ASO targeting LINC00680 substantially suppressed ESCC both in vitro and in vivo. Conclusions: An oncogenic lncRNA, LINC00680, was identified in ESCC, which functions as a ceRNA by sponging miR-423-5p to promote PAK6 expression and ESCC. LINC00680/miR-423-5p/PAK6 axis may serve as promising diagnostic and prognostic biomarkers and therapeutic targets for ESCC.
Project description:Esophageal cancer is a lethal malignancy with high mortality rate, while the molecular mechanisms underlying esophageal cancer pathogenesis are stillis poorly understood. Here we found that the N6-methyladenosine (m6A) methyltransferase METTL3 is significantly up-regulated in esophageal squamous cell carcinoma (ESCC) and associated with poor patient prognosis. Depletion of METTL3 results in decreased ESCC growth and progression in vitro and in vivo. We further established ESCC initiation and progression models using Mettl3 conditional knockout mouse and revealed that Mettl3 mediated m6A modification is essential for promotes ESCC initiation and progression in vivo. Moreover, using METTL3 overexpression ESCC cell model and Mettl3 conditional knockin mouse model, we demonstrated the critical function of Mettl3 in promoting in vivo ESCC tumorigenesis in vitro and in vivo. Mechanistically, Mettl3 catalyzed m6A modification promotes NOTCH1 expression and the activation of Notch signaling pathway. Forced activation of Notch signaling pathway successfully rescues the growth, migration and invasion capacities of METTL3 depleted ESCC cells. Our data uncovered important mechanistical insights underlying ESCC tumorigenesis and provided molecular basis for the development of novel strategies for ESCC diagnosis and treatment.
Project description:To further verify the underlying functions of Bit1 in ESCC, therefore, in the present study, we examined Bit1 expression in a panel of ESCC cell lines, and investigated the effects of Bit1 knockdown on tumor growth, migration and invasion as well as cell apoptosis in ESCC, and further preliminarily elucidated the possible molecular mechanisms. All data presented herein suggest Bit1 may be a promising molecular target for the therapy of ESCC, and thus intervention of Bit1 may lead to better therapeutic outcomes for the patients with ESCC. To further verify the underlying functions of Bit1 in ESCC, therefore, in the present study, we examined Bit1 expression in a panel of ESCC cell lines, and investigated the effects of Bit1 knockdown on tumor growth, migration and invasion as well as cell apoptosis in ESCC, and further preliminarily elucidated the possible molecular mechanisms. All data presented herein suggest Bit1 may be a promising molecular target for the therapy of ESCC, and thus intervention of Bit1 may lead to better therapeutic outcomes for the patients with ESCC. EC9706 cells were harvested 72 h after transfection with pSilencer3.1-H1 -neo-Bit1-shRNA or pSilencer3.1-H1-neo-negative-shRNA. Approximate 1â??Ã?â??106 cells from each sample were subjected to gene microarray assay. Total RNA was extracted was extracted for analysis.
Project description:Esophageal cancer remains a dominating cause of cancer-associated death and has shown a sharp increase of more than 6-fold increase rates all over the world. It is divided into two main pathological types: esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC). Though the treatment has been improved a lot, the prognosis is still very poor with overall survival rate at 5 year was 15%-25%. Elaiophylin is a novel autophagy inhibitor at the late stage, which is a C2 symmetric macrolides separated from Streptomyces niger. However, the function of it in esophageal cancer was never explored. EIF4B is an important component of eukaryotic transcription initiation complex, which can be recruited to the 5’ untranslated region (5’UTR) of the mRNA. In recent years, eIF4B was suggested to play an important role in the progression of a various cancer cells. In the study we presented here, we firstly confirmed that the Elaiophylin was a novel autophagy inhibitor in ESCC cells. Moreover, Elaiophylin can inhibit the proliferation and migration of ESCCs, and promotes apoptosis. Then, we using RNA-seq to identify the genes which were regulated by Elaiophylin and verify them by RT-qPCR assay. Finally, we found the activity of PI3K/AKT pathway was inhibited by Elaiophylin. And the mRNA and protein expression level of eIF4B was both downregulated by Elaiophylin. In order to further confirm whether eIF4B is a target of Elaiophylin, we transfected a EIF4B-OE plasmid to ESCC cells, and found that the eIF4B overexpression could block the effect which was resulted from Elaiophylin. And by transfecting a shRNA to ESCC cells, we found that knockdown of eIF4B could inhibit the proliferation and migration of ESCC cells and promotes apoptosis when compared with the control group. All the results suggest that Elaiophylin could inhibit the proliferation, invasion of ESCC cells and promote its apoptosis by targeting the eIF4B via PI3K/AKT signaling pathway. This result identified that the Elaiophylin might serve as a promising therapeutic medicine for esophageal cancer.
Project description:Objective: Esophageal squamous carcinoma (ESCC) is one of the most common gastrointestinal tumors, and the PI3K/AKT signaling pathway plays a key role in the development of ESCC. circRNAs have been reported to be involved in the regulation of PI3K/AKT signaling, but the underlying mechanisms are unclear. This study aimed to identify protein-coding circRNAs and investigate their function in ESCC. Design: Differential expression of circRNAs between ESCC tissues and adjacent normal tissues was identified using circRNA microarray analysis. A novel protein encoded by circ-PDE5A was identified by LC-MS/MS. Molecular biological methods were used to explore the biological functions and regulatory mechanisms of circ-PDE5A and its encoded PDE5A-500aa novel protein in ESCC. Construction of a nanoplatform for the coupling of circRNAs to investigate the therapeutic translation value of circ-PDE5A. Results: We found that circ-PDE5A expression was downregulated in ESCC cells and tissues, and its low expression was associated with later clinicopathological staging and poorer prognosis. Functionally, circ-PDE5A inhibited ESCC proliferation and metastasis in vitro and in vivo by encoding the novel PDE5A-500aa protein, which was identified as a key player in regulating PI3K/AKT signaling activation in ESCC. Mechanistically, the novel PDE5A-500aa protein binds directly to PIK3IP1 and promotes USP14-mediated deubiquitination of the k48-linked polyubiquitin chain at residue K198 of PIK3IP1, thereby attenuating PI3K/AKT pathway in ESCC. In addition, the circ-PDE5A plasmid-coupled reduction-responsive nanoplatform successfully inhibited ESCC growth and metastasis. Conclusions: circ-PDE5A represents an epigenetic mechanism regulating PI3K/ATK signaling and serves as a novel and promising therapeutic target and prognostic marker for ESCC.
Project description:Objective: Esophageal squamous carcinoma (ESCC) is one of the most common gastrointestinal tumors, and the PI3K/AKT signaling pathway plays a key role in the development of ESCC. circRNAs have been reported to be involved in the regulation of PI3K/AKT signaling, but the underlying mechanisms are unclear. This study aimed to identify protein-coding circRNAs and investigate their function in ESCC. Design: Differential expression of circRNAs between ESCC tissues and adjacent normal tissues was identified using circRNA microarray analysis. A novel protein encoded by circ-PDE5A was identified by LC-MS/MS. Molecular biological methods were used to explore the biological functions and regulatory mechanisms of circ-PDE5A and its encoded PDE5A-500aa novel protein in ESCC. Construction of a nanoplatform for the coupling of circRNAs to investigate the therapeutic translation value of circ-PDE5A. Results: We found that circ-PDE5A expression was downregulated in ESCC cells and tissues, and its low expression was associated with later clinicopathological staging and poorer prognosis. Functionally, circ-PDE5A inhibited ESCC proliferation and metastasis in vitro and in vivo by encoding the novel PDE5A-500aa protein, which was identified as a key player in regulating PI3K/AKT signaling activation in ESCC. Mechanistically, the novel PDE5A-500aa protein binds directly to PIK3IP1 and promotes USP14-mediated deubiquitination of the k48-linked polyubiquitin chain at residue K198 of PIK3IP1, thereby attenuating PI3K/AKT pathway in ESCC. In addition, the circ-PDE5A plasmid-coupled reduction-responsive nanoplatform successfully inhibited ESCC growth and metastasis. Conclusions: circ-PDE5A represents an epigenetic mechanism regulating PI3K/ATK signaling and serves as a novel and promising therapeutic target and prognostic marker for ESCC.
Project description:To further verify the underlying functions of Bit1 in ESCC, therefore, in the present study, we examined Bit1 expression in a panel of ESCC cell lines, and investigated the effects of Bit1 knockdown on tumor growth, migration and invasion as well as cell apoptosis in ESCC, and further preliminarily elucidated the possible molecular mechanisms. All data presented herein suggest Bit1 may be a promising molecular target for the therapy of ESCC, and thus intervention of Bit1 may lead to better therapeutic outcomes for the patients with ESCC. To further verify the underlying functions of Bit1 in ESCC, therefore, in the present study, we examined Bit1 expression in a panel of ESCC cell lines, and investigated the effects of Bit1 knockdown on tumor growth, migration and invasion as well as cell apoptosis in ESCC, and further preliminarily elucidated the possible molecular mechanisms. All data presented herein suggest Bit1 may be a promising molecular target for the therapy of ESCC, and thus intervention of Bit1 may lead to better therapeutic outcomes for the patients with ESCC.
Project description:Esophageal squamous cell carcinoma (ESCC) is the sixth leading cause of cancer death worldwide. Emerging evidence suggests that the androgen receptor (AR) is involved in ESCC tumorigenesis. However, how AR exerts its genomic functions in ESCC remains unknown. Here, by defining AR cistromes and analyzing androgen-regulated transcriptomes, we find that AR downregulates the majority of its target genes in ESCC cells. We further find that the pioneer factor GATA3 governs AR-repressed transcription by recruiting SMRT/HDAC3 co-repressors to target gene loci. Importantly, genetic inhibition of GATA3 or pharmacological inhibition of AR/HDAC3 relieves AR-mediated gene repression, leading to ESCC cell growth inhibition in vitro and in vivo. Our findings reveal molecular mechanisms underlying the oncogenomic function of AR in ESCC and identify the GATA3-directed AR transcriptional repression program as a therapeutic target for ESCC.
Project description:To investigate the function of USP36 in the regulation of cell proliferation and escc progression, we established eca109 cell lines in which each target gene has been knocked down by siRNA.We then performed gene expression profiling analysis using data obtained from RNA-seq of 6 different cells at same time points.