ABSTRACT
The purpose of this study was to investigate the anti-cancer effect of melittin on growth, migration, invasion, and apoptosis of non-small-cell lung cancer (NSCLC) cells. This study also explored the potential anti-cancer mechanism of melittin in NSCLC cells. The results demonstrated that melittin suppressed growth, migration, and invasion, and induced apoptosis of NSCLC cells in vitro. Melittin increased pro-apoptotic caspase-3 and Apaf-1 gene expression. Melittin inhibited tumor growth factor (TGF)-β expression and phosphorylated ERK/total ERK (pERK/tERK) in NSCLC cells. However, TGF-β overexpression (pTGF-β) abolished melittin-decreased TGF-β expression and pERK/tERK in NSCLC cells. Treatment with melittin suppressed tumor growth and prolonged mouse survival during the 120-day observation in vivo. Treatment with melittin increased TUNEL-positive cells and decreased expression levels of TGF-β and ERK in tumor tissue compared to the control group. In conclusion, the findings of this study indicated that melittin inhibited growth, migration, and invasion, and induced apoptosis of NSCLC cells through down-regulation of TGF-β-mediated ERK signaling pathway, suggesting melittin may be a promising anti-cancer agent for NSCLC therapy.
Subject(s)
Animals , Rabbits , Apoptosis , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/drug therapy , MAP Kinase Signaling System , Lung Neoplasms/genetics , Lung Neoplasms/drug therapy , Melitten/pharmacology , Down-Regulation , Gene Expression Regulation, Neoplastic , Cell Movement , Transforming Growth Factor beta/metabolism , Cell Line, Tumor , Caspase 3 , Apoptotic Protease-Activating Factor 1 , Neoplasm InvasivenessABSTRACT
The purpose of this study was to investigate the anti-cancer effect of melittin on growth, migration, invasion, and apoptosis of non-small-cell lung cancer (NSCLC) cells. This study also explored the potential anti-cancer mechanism of melittin in NSCLC cells. The results demonstrated that melittin suppressed growth, migration, and invasion, and induced apoptosis of NSCLC cells in vitro. Melittin increased pro-apoptotic caspase-3 and Apaf-1 gene expression. Melittin inhibited tumor growth factor (TGF)-ß expression and phosphorylated ERK/total ERK (pERK/tERK) in NSCLC cells. However, TGF-ß overexpression (pTGF-ß) abolished melittin-decreased TGF-ß expression and pERK/tERK in NSCLC cells. Treatment with melittin suppressed tumor growth and prolonged mouse survival during the 120-day observation in vivo. Treatment with melittin increased TUNEL-positive cells and decreased expression levels of TGF-ß and ERK in tumor tissue compared to the control group. In conclusion, the findings of this study indicated that melittin inhibited growth, migration, and invasion, and induced apoptosis of NSCLC cells through down-regulation of TGF-ß-mediated ERK signaling pathway, suggesting melittin may be a promising anti-cancer agent for NSCLC therapy.
Subject(s)
Apoptosis , Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , MAP Kinase Signaling System , Melitten/pharmacology , Animals , Apoptotic Protease-Activating Factor 1 , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/genetics , Caspase 3 , Cell Line, Tumor , Cell Movement , Down-Regulation , Gene Expression Regulation, Neoplastic , Lung Neoplasms/drug therapy , Lung Neoplasms/genetics , Mice , Neoplasm Invasiveness , Transforming Growth Factor beta/metabolismSubject(s)
Granuloma, Plasma Cell/diagnosis , Liver Diseases/diagnosis , Biopsy , Diagnosis, Differential , Female , Granuloma, Plasma Cell/diagnostic imaging , Granuloma, Plasma Cell/pathology , Humans , Liver Diseases/diagnostic imaging , Liver Diseases/pathology , Liver Function Tests , Magnetic Resonance Imaging , Middle Aged , Positron Emission Tomography Computed Tomography , Predictive Value of Tests , Remission, Spontaneous , Time FactorsABSTRACT
DNA from a region downstream of and overlapping the polyketide synthase (PKS) gene cluster for jadomycin B biosynthesis in Streptomyces venezuelae was cloned and sequenced. Analysis of the nucleotide sequence located one complete ORF (ORF6), an incomplete one representing the 3' region of ORF4 in the PKS cluster, and a second incomplete one (ORF7). The deduced amino acid sequences for ORFs 6 and 7 resemble those of oxygenases. Since a plausible biosynthetic pathway for jadomycin B includes an angular polyketide intermediate that undergoes oxidative ring fission before condensation with an amino acid, we subcloned one of the presumptive oxygenase genes (ORF6) in a segregationally unstable shuttle vector (pHJL400) and disrupted it by inserting the gene for apramycin resistance. Transformation of S. venezuelae with the disruption vector and selection for apramycin resistance gave mutants blocked in jadomycin biosynthesis. Southern hybridization confirmed that gene replacement had occurred. Cultures of the mutants accumulated a metabolite identified by comparison with an authentic sample as rabelomycin, a non-nitrogenous polyketide-derived antibiotic originally isolated from Streptomyces olivaceus.