The Contrasting Role of the Mediator Subunit MED30 in the Progression of Bladder Cancer.

Background/Aim: The Mediator complex is a key regulator of gene transcription, and several studies have demonstrated altered expression of particular subunits in diverse human diseases, especially cancer. To date, nothing is known about the role of MED30 in bladder cancer. Materials and Methods: We, therefore, performed an RNA expression and survival analysis of the subunit MED30 in 537 samples of bladder cancer by using the database cBioPortal. To validate these data on the protein level, we practiced immunohistochemical staining against MED30 on a tissue microarray containing 210 samples of all tumour stages and performed survival analyses. For functional analysis, the siRNA-mediated knockdown of MED30 was performed in the cell lines T24 and TCCSUP followed by proliferation, migration, and invasion assays. Results: On the mRNA and protein levels, higher expression of MED30 is associated with better patient survival. In accordance with this, advanced T-and N-stages showed lower expression of MED30. In contrast, knockdown of MED30 led to reduction of the tumour parameters proliferation, migration, and invasion in the BCa cell lines. Conclusion: MED30 appears to be integrated in the progression of the urothelial tumour in the bladder.