Background: Malignant cells detach from the parent tumor and invade other tissues and organs during metastasis. Epithelial to mesenchymal transition (EMT) has been reported to be involved in cancer dissemination so we established a chemically induced EMT model in cancer cell line. This will help to understand the biophysical mechanisms within the cellular microenvironment that initiate metastasis.
Materials and Methods: Human renal cell carcinoma cells (A498) were exposed to cyclosporine (Sigma) in a dose and time dependent manner. The final dose of cyclosporine was based on the biophysical changes in cell morphology. Cytotoxicity of the selected dose was evaluated by MTT assay. Expression of various epithelial and mesenchymal markers was evaluated by real time PCR and immunostaining to confirm the EMT signature. Migration, invasive potential, colony formation and lineage-specific differentiation ability of the EMT induced cells were evaluated and compared with the parent cells.
Results & Conclusion: Light microscopy images revealed a distinct change in morphology of the A498 cells with cyclosporine treatment at a non-cytotoxic dose. RT-PCR data showed a significant decrease in E-cadherin expression in cyclosporine treated cells. Concomitantly there was up-regulation of the mesenchymal markers, vimentin ,Snail, Twist in the treated cells. Cyclosporine was found to increase motility and invasive potential of the cells. EMT cells showed increased colony formation and a tendency to differentiate into adipocytes, osteocytes and neurocytes under respective differentiation media while the non-treated A498 cells failed to differentiate. Thus, cyclosporine treatment can lead to EMT and this can serve as an in vitro model to study the cellular changes leading to invasion and metastasis.