Bai C.,Changhai Hospital |
Liu X.,Institute of Cardiothoracic Surgery |
Zheng J.-M.,Changhai Hospital |
Zheng J.-M.,Institute of Molecular Pathology |
And 5 more authors.
Evidence suggests that different types of mutation in gastrointestinal stromal tumours (GISTs) correlate with different response rates to imatinib (Glivec, STI571). The purpose of this study was to explore the sensitivity of the PDGFRA L839P mutant, a novel gain-of-function mutation isoform related to GISTs, to imatinib in vitro. The eukaryotic expression vectors pcDNA3.1-PDGFRA Wild, pcDNA3.1-PDGFRA D842V and pcDNA3.1-PDGFRA L839P were constructed and transfected into Chinese hamster ovary (CHO) cells by liposome methods. The responses of cells with PDGFRA Wild, PDGFRA L839P and PDGFRA D842V mutants to imatinib were determined by methyl thiazolyl tetrazolium (MTT) assay, western blotting and apoptosis assays. Reults of the MTT assay revealed that the growth rate of CHO(PDGFRA L839P) cells decreased to approximately 60% when exposed to 1 μM imatinib and to approximately 50% with 5 μM imatinib. However, the growth rate of CHO(PDGFRA D842V) cells did not significantly change with 5 μM imatinib. Western blot analysis indicated that 1 μM imatinib completely blocked the phosphorylation of PDGFRA L839P, but did not affect PDGFRA D842V phosphorylation. Apoptosis analysis suggested that the percentage of apoptotic CHO(PDGFRA L839P) cells increased approximately 4-fold (from 5.90 to 25.2%) with 1 μM imatinib. Although the treatment of CHO(PDGFRA D842V) and CHO(PDGFRA Wild). Source
Huang S.-D.,Institute of Cardiothoracic Surgery |
Yuan Y.,Institute of Cardiothoracic Surgery |
Zhuang C.-W.,Fuzhou General Hospital of Nanjing Command |
Li B.-L.,Changhai Hospital |
And 4 more authors.
Background: The enhancer of zeste homolog 2 (EZH2) was found to be overexpressed and associated with tumor metastasis in esophageal squamous cell carcinoma (ESCC). On the other hand, it was reported that miR-26a, miR-98, miR-101, miR-124, miR-138 and miR-214 could inhibit the expression of EZH2 in some tumors. However, the role of miRNAs in the regulation of EZH2 expression in human ESCC has not been documented. The aim of this study was to determine the role of these miRNAs in the regulation of tumor metastasis via EZH2 overexpression in human ESCC.Methods and results: The expression of these miRNAs and EZH2 mRNA were examined by qPCR and the expression of EZH2 protein was detected by western blot. The role of these miRNAs in migration and invasion was studied in ESCC cell line (Eca109) transfected with miRNA mimics or cotransfected with miRNA mimics and pcDNA-EZH2 plasmid (without the 3'-UTR of EZH2). Through clinical investigation, we found that miR-98 and miR-214 expression was significantly lower in ESCC tissues than in matched normal tissues, and the expression level of miR-98 and miR-214 was inversely correlated to EZH2 protein expression and the clinical features such as pathological grade, tumor stage and lymph node metastasis in ESCC. In Eca109 cells, overexpression of miR-98 and miR-214 significantly inhibited the migration and invasion of ESCC cells, which was reversed by transfection of EZH2.Conclusions: These findings suggest that decreased expression of miR-98 and miR-214 might promote metastasis of human ESCC by inducing accumulation of EZH2 protein. © 2012 Yuan et al.; licensee BioMed Central Ltd. Source
Shi G.-Z.,Yixing Peoples Hospital |
Yuan Y.,Shanghai University |
Jiang G.-J.,Yixing Peoples Hospital |
Ge Z.-J.,Yixing Peoples Hospital |
And 7 more authors.
Background: Prenylated Rab acceptor 1 domain family member 3 (PRAF3) is involved in the regulation of many cellular processes including apoptosis, migration and invasion. This study was conducted to investigate the effect of PRAF3 on apoptosis, migration and invasion in human esophageal squamous cell carcinoma (ESCC).Methods: The expression of PRAF3 mRNA and protein in primary ESCC and the matched normal tissues (57cases) was determined by quantitative RT-PCR and Western blot. Immunohistochemical analysis of PRAF3 expression was carried out in paraffin-embedded sections of ESCC and correlated with clinical features. The role of PRAF3 in apoptosis, migration and invasion was studied in ESCC cell lines of Eca109 and TE-1 through the adenovirus mediated PRAF3 gene transfer. The effect of PRAF3 on apoptosis was analyzed by annexin V-FITC assay. The regulation of PRAF3 on migration was determined by transwell and wounding healing assay, while the cellular invasion was analyzed by matrigel-coated transwell assay.Results: We found that the expression of PRAF3 was significantly down-regulated in ESCC tissue compared with the matched normal tissue and was correlated with the clinical features of pathological grade, tumor stage and lymph node metastasis. Moreover, overexpression of PRAF3 induced cell apoptosis through both caspase-8 and caspase-9 dependent pathways, and inhibited cell migration and invasion by suppressing the activity of both MMP-2 and MMP-9 in human ESCC cell lines.Conclusions: Our data suggest that PRAF3 plays an important role in the regulation of tumor progression and metastasis and serves as a tumor suppressor in human ESCC. We propose that PRAF3 might be used as a potential therapeutic agent for human ESCC. © 2012 Shi et al; licensee BioMed Central Ltd. Source
Zhao T.,Institute of Cardiothoracic Surgery |
Chen H.,Institute of Cardiothoracic Surgery |
Dong Y.,Changhai Hospital |
Zhang J.,Institute of Cardiothoracic Surgery |
And 3 more authors.
International Journal of Nanomedicine
In order to improve the therapeutic efficacy and minimize the side effects of lung cancer chemotherapy, the formulation of paclitaxel-loaded poly(glycolide-co-ε-caprolactone)-b-D-α-tocopheryl polyethylene glycol 2000 succinate nanoparticles (PTX-loaded [PGA-co-PCL]-b-TPGS2k NPs) was prepared. The novel amphiphilic copolymer (PGA-co-PCL)-b-TPGS2k was synthesized by ring-opening polymerization and characterized by proton nuclear magnetic resonance spectroscopy and gel permeation chromatography. The PTX-loaded (PGA-co-PCL)-b-TPGS2k NPs were characterized in terms of size, size distribution, zeta potential, drug encapsulation, surface morphology, and drug release. In vitro cellular uptakes of NPs were investigated with confocal laser scanning microscopy, indicating the coumarin 6-loaded (PGA-co-PCL)-b-TPGS2k NPs could be internalized by human lung cancer A-549 cells. The antitumor effect of PTX-loaded NPs was evaluated, both in vitro and in vivo, on an A-549 cell tumor-bearing mouse model via intratumoral injection. The commercial PTX formulation Taxol was chosen as the reference. Experimental results showed that the PTX-loaded NPs possessed higher cytotoxicity and could effectively inhibit the growth of tumor. All the results suggested that amphiphilic copolymer (PGA-co-PCL)-b-TPGS2k could act as a potential biological material for nanoformulation in the treatment of lung cancer. © 2013 Zhao et al, publisher and licensee Dove Medical Press Ltd. Source