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AIM:Heparanase degrades heparan sulfate proteoglycans(HSPGs) and is a critical mediator of tumor metastasis andangiogenesis.Recently,it has been cloned as a single genefamily and found to be a potential target for antimetastasisdrugs.However,the molecular basis for the regulation ofheparanase expression is still not quite clear.The aim ofthis study was to determine whether the expression ofeukaryotic initiation factor 4E (eIF-4E) correlated with theheparanase level in tumor cells and to explore the correlationbetween heparanase expression and metastatic potential ofLS-174T cells.METHODS:A 20-mer antisense s-oligodeoxynucleotide(asODN) targeted against the translation start site of eIF-4EmRNA was introduced into LS-174T cells by lipid-mediatedDNA-transfection.eIF-4E protein and mRNA levels weredetected by Western blot analysis and RT-PCR,respectively.Heparanase activity was defined as the ability to degradehigh molecular weight (40-100 kDa) radiolabeled HS (heparansulfate) substrate into low molecular weight (5-15 kDa) HSfragments that could be differentiated by gel filtrationchromatography.The invasive potential of tumor cell in vitrowas observed by using a Matrigel invasion assay system.RESULTS:The 20-mer asODN against eIF-4E specificallyand significantly inhibited eIF-4E expression at bothtranscriptional and translational levels.As a result,theexpression and activity of heparanase were effectivelyretarded and the decreased activity of heparanase resultedin the decreased invasive potential of LS-174T.CONCLUSION: eIF-4E is involved in the regulation of heparanase production in colon adenocarcinoma cell line LS-174T, and its critical function makes it a particularly interesting target for heparanase regulation. This targeting strategy in antisense chemistry may have practical applications in experimental or clinical anti-metastatic gene therapy of human colorectal carcinoma.
AIM: Heparanase degrades heparan sulfate proteoglycans (HSPGs) and is a critical mediator of tumor metastasis and angiogenesis. Recently, it has been cloned as a single gene family and found to be a potential target for antimetastasis drugs.However, the molecular basis for the regulation of heparanase expression is still not quite clear. The aim of this study was to determine whether the expression of eukaryotic initiation factor 4E (eIF-4E) correlated with the hemparanase level in tumor cells and to explore the correlation between heparanase expression and metastatic potential of LS-174T cells. METHODS: A 20-mer antisense s-oligodeoxynucleotide (asODN) targeted against the translation start site of eIF-4E mRNA was introduced into LS-174T cells by lipid-mediated DNA-transfection. IF-4E protein and mRNA levels were detected by Western blot analysis and RT-PCR , respectively. Heparanase activity was defined as the ability to degrade high molecular weight (40-100 kDa) radiolabeled HS (heparansulfate) substrate int o low molecular weight (5-15 kDa) HSfragments that could be differentiated by gel filtrationchromatography. The invasive potential of tumor cells in vitrowas observed by using a Matrigel invasion assay system .RESULTS: The 20-mer asODN against eIF-4E and specifically inhibited eIF-4E expression at both transcription and translational levels. As a result, the expression and activity of heparanase were effectivelyretarded and the decreased activity of heparanase resultedin the less invasive potential of LS-174T.CONCLUSION: eIF-4E is involved in the regulation of heparanase production in colon adenocarcinoma cell line LS-174T, and its critical function makes it a very interesting target for heparanase regulation. This targeting strategy in antisense chemistry may have practical applications in experimental or clinical anti-metastatic gene therapy of human colorectal carcinoma.