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Introduction: Wnt and k-ras are two main signaling pathways activated in colon cancer.Many genes are upregulated downstream of these signaling pathways. The aim of this studywas to assess the activity of Wnt and k-ras in HCT116 and SW480 cell lines by makingtwo reporter constructs using promoters downstream of these pathways (fibroblast growthfactor18 [FGF18] and urokinase plasminogen activator receptor [UPAR]).Materials and Methods: UPARLacZ, FGF18LacZ, negative (pUCLacZ) and positive (CMVLacZ)control plasmids and pRc/CMV2CAT were constructed. Expressions of LacZ in bothcell lines were studied by βgal staining and ELISA after normalization with CAT expression.Results: In both cell lines, FGF18LacZ transfected cells stained more than UPARLacZ transfectedones. This difference was more prominent in SW480. Both constructs have the abilityof expression in both cell lines. It was also proven that FGF18LacZ was significantly moreactive than UPARLacZ in both cell lines. Expression of FGF18LacZ in HCT116 and SW480cell lines was respectively 1.34 and 4.4 times more than UPARLacZ.Conclusion: Despite the fact that in HCT116 the Ras pathway is activated, FGF18LacZ ismore active than UPARLacZ although the UPAR promoter is more active in HCT116 cell linethan SW480 cell line. These findings are in accordance with previous studies that in all coloncancer cell lines Wnt signaling pathway is active even though there is no mutation in anypart of it. Wnt is the main signaling pathway responsible for carcinogenesis in colon epithelialcells. These constructs can be used as reporters for studying the above mentioned signalingpathways in other cell lines.