RESUMEN
Hepatocellular carcinoma (HCC) is a commonly occurring malignant tumor, with a high incidence rate. The present study aimed to investigate the effect of knocking down the NglycosyltransferaseV (GnTV) protein on the proliferation, migration and invasion of the human HCC drugresistant cell line, SMMC7721/R. SMMC7721/R cells with GnTVknockdown (SMMC7721/RGnTV) were constructed using the method of lentiviral transfection. The expression of GnTV was assessed using reverse transcriptionquantitative polymerase chain reaction (RTqPCR) and western blotting. Cell proliferation was determined using an MTT assay, and the extent of cellular apoptosis was assessed using flow cytometric analysis. Additionally, the metastatic ability of the cells in vitro was analyzed using cell adhesion and invasion assays. Western blotting was used to investigate the protein expression levels of caspase3, caspase9, Bcl2, Bax, matrix metalloproteinase (MMP)2 and MMP9, and RTqPCR was used to determine the mRNA expression levels of the genes for the breast cancer resistance protein and Pglycoprotein in the SMMC7721/R cells. Taken together, the results of the present study revealed that the knockdown of GnTV significantly suppressed the proliferation, migration and invasion (P<0.05) of the SMMC7721/R cells. Furthermore, the possible mechanism underlying these phenomena may be associated with the induction of mitochondriamediated apoptosis, inhibition of the degradation of the extracellular matrix and an enhancement of the drug-sensitivity. GnTVknockdown may therefore be used to treat drugresistant HCC in the future.
Asunto(s)
Carcinoma Hepatocelular/enzimología , Carcinoma Hepatocelular/patología , Movimiento Celular , Resistencia a Antineoplásicos , Neoplasias Hepáticas/enzimología , Neoplasias Hepáticas/patología , N-Acetilglucosaminiltransferasas/metabolismo , Apoptosis/genética , Carcinoma Hepatocelular/genética , Caspasas/metabolismo , Adhesión Celular , Línea Celular Tumoral , Proliferación Celular , Regulación hacia Abajo/genética , Resistencia a Antineoplásicos/genética , Citometría de Flujo , Regulación Neoplásica de la Expresión Génica , Técnicas de Silenciamiento del Gen , Humanos , Neoplasias Hepáticas/genética , Invasividad Neoplásica , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , TransfecciónRESUMEN
The apparent partition constants of two amphiphilic peptides, Amp1 and Amp2, for partitioning into phosphatidylglycerol/phosphatidylcholine bilayer were measured using size-exclusion high performance liquid chromatograph. The exposed amino groups of vesicle-bound peptides were studied by TNBS assay. It was proposed that their N-terminals were exposed to the aqueous phase, and that the main explanation for the stronger interaction of Amp1 with lipid bilayer compared with Amp2 was its stronger lipid binding ability, though Amp1 was also buried deeper in the lipid membrane. It was also found that the two peptides were polymerized in buffer, with their amino groups almost totally buried within the polymers.
RESUMEN
Two amphiphilic peptides, Amp1 and Amp2, were synthesized according to the sequence of the lipid-binding domain in apolipoprotein. Amp2 has a Val residue substituted for the Lys at the 4th position of Amp1. Intrinsic fluorescence spectra, peptide-induced leakage of calcein-laoded liposomes, quenching of tryptophan fluorescene by iodide and acrylamide, circular dichroism spectra, and measurement of the membrane penetration depth of tryptophan residue with spin-labeled phospholipids indicate unexceptionally that Amp1 interacted more strongly with the lipid bilayer than Amp2. It is proposed that class A amphiphilic alpha-helix is buried in the membrane in such a way that its long axis is oriented parallel to the membrane plane, and the electrostatic interaction between the positively charged residues located at the polar-nonpolar interface of the amphiphilic helix with the negatively charged head groups of phospholipids is important to the lipid affinity of the amphiphilic peptide.
RESUMEN
Two amphiphilic peptides, Ampl and Amp2, were synthesized according to the sequence of the lipid-binding domain in apoliporotein. Amp2 has a Val residue substituted for the Lys at the 4th position of Ampl. Interaction between Ampl / Amp2 and liposomes with different lipid compositions were compared by studying the blue shifts of the intrinsic fluorescence emission maxima, the peptide-induced lipsome leakage and the quenching of tryptophan fluorescence by acrylamide. The influence of temperature on interactions was studied as well. Ampo1 interacted stronger with acidic lipids while Amp2 interacted stronger with zwitterionic lipids. The interaction was reinforced with the increasing extent of lipid unsaturation as well as with the increase of temperature. The lipid unsaturation had amore prominent effect.