ABSTRACT
<p><b>OBJECTIVE</b>To investigate the function and mechanism of 3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole (YC-1) on activity of VEGF and GPI genes in human pancreatic cancer PC-3 cells incubated under hypoxic conditions.</p><p><b>METHODS</b>Human pancreatic cancer PC-3 cells were incubated under hypoxic culture conditions. Immunocytochemical staining was used to detect HIF-1alpha protein expression in hypoxic and normoxic PC-3 cells. Semi-quantitative RT-PCR was used to detect the effect of YC-1 on the expression of VEGF and GPI mRNA and HIF-1alpha protein in PC-3 cells. Effect of YC-1 on the expression of HIF-1alpha protein was examined by Western blotting. MTF assay was used to detect proliferation of hypoxicPC-3 cells.</p><p><b>RESULTS</b>HIF-1alpha expression was mainly located in nuclei in hypoxic PC-3 cells. The mRNA synthesis of VEGF and GPI and the protein expression of HIF-1alpha were significantly decreased in the group treated with the highest concentration of YC-1 (100 micromol/L). Compared to placebo, YC-1 inhibited the proliferation of hypoxic PC-3 cells greatly when it was increased to 100 micromol/L.</p><p><b>CONCLUSION</b>YC-1 inhibited the transcription of VEGF and GPI in hypoxic human pancreatic cancer PC-3 cells. It was induced by down-regulation of HIF-1alpha protein. YC-1 inhibites the proliferation of PC-3 cells exposed to hypoxic conditions.</p>
Subject(s)
Humans , Blotting, Western , Cell Hypoxia , Cell Line, Tumor , Cell Proliferation , Enzyme Activators , Pharmacology , Gene Expression Regulation, Neoplastic , Glucose-6-Phosphate Isomerase , Genetics , Metabolism , Hypoxia-Inducible Factor 1, alpha Subunit , Metabolism , Indazoles , Pharmacology , Pancreatic Neoplasms , Metabolism , Pathology , RNA, Messenger , Genetics , Metabolism , Reverse Transcriptase Polymerase Chain Reaction , Transcription, Genetic , Vascular Endothelial Growth Factors , Genetics , MetabolismABSTRACT
<p><b>OBJECTIVE</b>To identify the activity of hammerhead ribozyme against transforming growth factor beta1 (TGFbeta1) in a cell-free system and in activated hepatic stellate cells (HSCs).</p><p><b>METHODS</b>The ribozyme against TGFb1 was designed with computer software. The transcripts of ribozyme, disabled ribozyme and target RNAs were prepared using the RiboMAX large scale RNA production system. The in vitro cleavage reactions were performed through incubation of 32P-labeled target RNAs with ribozyme or disabled ribozyme in different conditions. The eukaryotic expression vector encoding ribozyme and disabled ribozyme were constructed, and then transfected into HSC-T6 cells which exhibited characteristics of activated HSCs. The intracellular activity of the ribozyme was determined by detecting the ribozyme, disabled ribozyme and the TGFbeta1 expression.</p><p><b>RESULTS</b>The ribozyme cleaved target RNAs into anticipated products effectively. As expected, the disabled ribozyme possessed no cleavage activity in vitro. Further study demonstrated that the ribozyme expressed efficiently and inhibited TGFbeta1 expression in activated HSCs, while the disabled ribozyme displayed only a slight effect on TGFbeta1 expression.</p><p><b>CONCLUSION</b>The ribozyme with perfect cleavage activity in the cell-free system used inhibited TGFbeta1 expression effectively in activated HSCs. This ribozyme can provide a potential therapeutic approach for liver fibrosis.</p>