e22021 Background: Given the role of vinflunine (VFL) in the microtubule dynamics and the link between microtubules and cell adhesions through cadherins, we have investigated the possible influence of VFL on adherens junctions through its interaction with microtubules. We have studied the implication of VFL on the reversion of epithelial-mesenchymal transition (EMT) in bladder transitional cell carcinoma and explored a possible novel molecular mechanism. Methods: Four human bladder transitional carcinoma cell lines were used to carry out the following experimental procedure: Cytotoxicity assay by using MTT assay, qRTPCR to analyze mRNA markers of the EMT, Western blotting using specific antibodies for EMT markers, and immunofluorescence images, analyzed by epifluorescence microscopy. Results: Cell growth reduction was detected in human bladder carcinoma cells under VFL treatment compared to control. VFL induces mesenchymal to epithelial phenotype and modulates the EMT markers: E-cadherin and Cytokeratin-19 were enhanced under treatment, while significantly reduction of mRNA mesenchymal markers expression (Vimentin, N-cadherin) and EMT-transcriptional factors (Snail and Zeb1) was detected. Strong reduction of Hakai protein was seen under VFL treatment. Hakai was discovered as an E3 ubiquitin-ligase that mediates the posttranslational downregulation of E-cadherin. Epifluorescence images showed that VFL treatment promotes E-cadherin localization specifically at cell-cell contact; while, Hakai expression decreases its expression in the nuclei and cytoplasm. Conclusions: These results suggest that VFL up-regulates E-cadherin contributing to mesenchymal to epithelial transition, and that Hakai modulation might be the molecular mechanism by which the increasing E-cadherin at cell-cell contacts in bladder carcinoma cell lines is detected. Given the relevant in vitro role of VFL on E-cadherin expression and on the reversion of EMT process, we hypothesized that VFL could exert a clinical benefit in delaying the metastasis in urothelial tumors.
Expression and potential role of chemokine receptor CXCR4 in human bladder carcinoma cell lines with different metastatic ability
