RESUMO
MicroRNAs (miRs) are associated with tumor progression in various cancers, such as gastric and hepatic carcinomas, and lung cancer. miR-301a is overexpressed and displays oncogenic activity in cancers. We investigated the biological involvement of miR-301a in osteosarcoma (OS). Quantitative real-time polymerase chain reaction (qRT-PCR) was used to analyze expression levels of miR-301a in 24 OS and matched adjacent non-tumor tissues. A miR-301a mimic was transferred into OS cell lines U-2 OS and MG-63 to upregulate miR-301a. The effects of miR-301a were investigated by examining cell proliferation, migration, and the cell cycle. The miR-301 target was predicted by TargetScan and confirmed by western blotting and qRT-PCR. The expression of miR-301a was significantly higher in OS tissues compared with the matched adjacent non-tumor tissues (0.959 ± 0.39 vs 3.9516 ± 1.18). Upregulated miR-301a significantly increased proliferation at 48 and 72 h compared to the negative control (U-2 OS: 2.11 ± 0.21 vs 2.88 ± 0.24; 2.70 ± 0.26 vs 3.71 ± 0.24; MG-63: 2.19 ± 0.20 vs 3.19 ± 0.22; 3.1 ± 0.25 vs 4.01 ± 0.27) and migration capability (U-2 OS: 100 ± 20.19 vs 150.68 ± 32.83; MG-63: 100 ± 17.20 vs 133.35 ± 26.26), and decreased apoptosis in both U-2 OS (10.87 ± 2.53 vs 4.01 ± 2.23) and MG-63 (15.26 ± 2.15 vs 8.25 ± 3.07). The cell cycle studies revealed that miR-301a caused an increase of the G2 population in U-2 OS (38.6 ± 6.58 vs 47.2 ± 7.27) and MG-63 (44.01 ± 5.28 vs 57.9 ± 4.25). Additional experiments indicated that CDC14A was upregulated by miR-301a (0.63 ± 0.06 vs 0.98 ± 0.06; 1.49 ± 0.25 vs 2.99 ± 0.14). Overexpressed miR-301a may increase CDC14A expression and promote cell proliferation and migration in OS cells. Therefore, miR- 301a may be useful for osteosarcoma diagnosis and therapy.
Assuntos
Carcinogênese/genética , MicroRNAs/biossíntese , Osteossarcoma/genética , Monoéster Fosfórico Hidrolases/biossíntese , Apoptose/genética , Ciclo Celular/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , MicroRNAs/genética , Osteossarcoma/patologia , Monoéster Fosfórico Hidrolases/genética , Proteínas Tirosina Fosfatases , Ativação Transcricional/genéticaRESUMO
The net synthesis of sucrose (Suc) is catalysed by the sequential action of Suc-phosphate synthase (SPS) and Suc-phosphate phosphatase (SPP). SPS and SPP from Anabaena sp. PCC 7120 (7120-SPS and 7120-SPP) define minimal catalytic units. Bidomainal SPSs, where both units are fused, occur in plants and cyanobacteria, but they display only SPS activity. Using recombinant proteins that have fused 7120-SPS and 7120-SPP, we demonstrated that they are bifunctional chimeras and that the arrangement 7120-SPS/SPP is the most efficient to catalyse the sequential reactions to yield Suc. Moreover, we present the first evidence of a bidomainal SPS present in the cyanobacterium Synechococcus elongatus PCC 7942 with both, SPS and SPP activity.
Assuntos
Proteínas de Bactérias/química , Glucosiltransferases/química , Monoéster Fosfórico Hidrolases/química , Sacarose/metabolismo , Synechococcus/enzimologia , Proteínas de Bactérias/biossíntese , Domínio Catalítico , Clonagem Molecular , Escherichia coli , Glucosiltransferases/biossíntese , Glucosiltransferases/isolamento & purificação , Cinética , Modelos Moleculares , Monoéster Fosfórico Hidrolases/biossíntese , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/química , Análise de Sequência de Proteína , Homologia Estrutural de ProteínaRESUMO
Pseudomonas aeruginosa phosphorylcholine phosphatase (PChP) is a periplasmic enzyme produced simultaneously with the hemolytic phospholipase C (PLc-H) when the bacteria are grown in the presence of choline, betaine, dimethylglycine or carnitine. Molecular analysis of the P. aeruginosa mutant JUF8-00, after Tn5-751 mutagenesis, revealed that the PA5292 gene in the P. aeruginosa PAO1 genome was responsible for the synthesis of PChP. The enzyme expressed in E. coli, rPChP-Ec, purified by a chitin-binding column (IMPACT-CN system, New England BioLabs) was homogeneous after SDS-PAGE analysis. PChP was also expressed in P. aeruginosa PAO1-LAC, rPChP-Pa. Both recombinant enzymes exhibited a molecular mass of approximately 40 kDa, as expected for the size of the PA5292 gene, and catalyzed the hydrolysis of phosphorylcholine, phosphorylethanolamine, and p-nitrophenylphosphate. The saturation curve of rPChP-Ec and rPChP-Pa by phosphorylcholine revealed that these recombinant enzymes, like the purified native PChP, also contained the high- and low-affinity sites for phosphorylcholine and that the enzyme activity was inhibited by high substrate concentration.