RESUMO
By using glyoxylic acid monohydrate as a promoter, a wide range of substances containing a C-SO2 bond could be obtained from N-substituted maleimides or quinones and sodium sulfinates. The protocol features mild reaction conditions, short reaction time, and good atomic economics, which provides an alternative protocol for the α-sulfonylation of α,ß-unsaturated ketones.
RESUMO
Four new species of Russula subsection Sardoninae from northern and southwestern China under coniferous and deciduous trees are proposed as R. begonia, R. photinia, R. rhodochroa, and R. rufa. Illustrations and descriptions of R. gracillima, R. leucomarginata, R. roseola, and the above four new species are provided based on evidence of morphological characters and phylogenetic analyses of the internal transcribed spacer (ITS), as well as the multi-locus of mtSSU, nLSU, rpb1, rpb2 and tef1-α. The relationships between these new species and allied taxa are discussed.
RESUMO
Three new species of Russulasection Ingratae, found in Guizhou and Jiangsu Provinces, southern China, are proposed: R.straminella, R.subpectinatoides and R.succinea. Photographs, line drawings and detailed morphological descriptions for these species are provided with comparisons against closely-related taxa. Phylogenetic analysis of the internal transcribed spacer (ITS) region supported the recognition of these specimens as new species. Additionally, R.indocatillus is reported for the first time from China and morphological and phylogenetic data are provided for the Chinese specimens.
RESUMO
Cell migration and invasion are triggered by a number of chemoattractants that stimulate intracellular signaling pathways through regulating reorganization of the actin cytoskeleton. Rac1, an intracellular signal transducer, regulates a variety of cell functions, including the organization of the cytoskeleton, cell migration, and invasion. However, currently, very little is known about the roles of Rac1 in the cytoskeleton formation and invasion of human colorectal cancer cells. In our study, Rac1-shRNA was used to silence the Rac1 to reduce its expression specifically in Lovo cells. Our studies showed that RNA interference-mediated deletion of Rac1 strongly inhibited lamellipodia formation, cell migration, and invasion of Lovo cells in vitro. The deletion of Rac1 can serve as an alterative therapy to inhibit the invasion and metastasis of colorectal cancer cells.
Assuntos
Movimento Celular , Neoplasias Colorretais/genética , Interferência de RNA , Proteínas rac1 de Ligação ao GTP/antagonistas & inibidores , Adesão Celular , Linhagem Celular Tumoral , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Citoesqueleto/metabolismo , Humanos , Microscopia Confocal , Pseudópodes/metabolismo , Deleção de Sequência , Transfecção , Proteínas rac1 de Ligação ao GTP/genética , Proteínas rac1 de Ligação ao GTP/metabolismoRESUMO
OBJECTIVE: The objective of this study was to assess the change of cytoskeleton and cell cycle in LoVo (human colorectal cancer) cell via gene silencing of Rac1 with RNA interference mediated by microbubble (SonoVue) and ultrasound (US). METHODS: The compound of plasmid Rac1-shRNA, LoVo cells, and SonoVue was exposed to US (1 MHz, 2 W/cm(2), 5 min). The expression of Rac1 mRNA and Rac1 protein was detected by RT-PCR and Western blot. Cytoskeleton was taken by confocal microscope in a random fashion. Cell invasion was assayed using modified Boyden chambers, and cell cycle and apoptosis were analyzed by flow cytometry in LoVo cells. RESULTS: Rac1 gene is overexpressed in human colorectal cancer cells, gene silencing of Rac1 with RNA interference mediated by microbubble and US strongly inhibited lamellipodia formation, cell invasion, and delayed cell cycle, as well as enhanced cell apoptosis of LoVo cells in vitro. CONCLUSION: Silencing Rac1 gene mediated by microbubble and US may become a new treatment option for the inhibition of the invasion and metastasis of colorectal cancer cells.
Assuntos
Neoplasias Colorretais/terapia , Inativação Gênica , Interferência de RNA , Proteínas rac1 de Ligação ao GTP/genética , Western Blotting , Ciclo Celular/genética , Linhagem Celular Tumoral , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Citoesqueleto/genética , Citometria de Fluxo , Humanos , Microbolhas , Microscopia Confocal , Invasividade Neoplásica/prevenção & controle , Metástase Neoplásica/prevenção & controle , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Ultrassonografia/métodosRESUMO
BACKGROUND: Rac1, the better characterized Rac subfamily member, can regulate a large variety of different functions, including the organization of the actin cytoskeleton, cell migration, cell cycle progression, and cell survival through engagement of specific effectors. However, very little is currently known about the expression of Rac1 in colorectal cancer cells and the roles of Rac1 in the cell cycle progression and cell survival of human colorectal cancer cells. OBJECTIVE: To assess the change of cytoskeleton and cell cycle in Lovo (human colorectal cancer) cell via deletion of Rac1 with RNA interference. METHODS: Rac1 protein of all selected human colorectal cancer cells and in human colorectal tissue was detected by Western blotting, Rac1-shRNA was used to silence the Rac1 to reduce its expression specifically in Lovo cells. RESULTS: Rac1 protein was overexpressed in human colorectal cancer cells and in human colorectal tissue, RNA interference-mediated deletion of Rac1 strongly prolonged cell cycle progression and enhanced cell apoptosis of Lovo cells in vitro. CONCLUSIONS: depletion of Rac1 by the use of RNAi can arrest Lovo Cells in G