Background:
Malignant Pleural Mesothelioma (MPM) is an aggressive disease associated with asbestos exposure with a median survival of 9-12 months after diagnosis. Chemotherapy is usually palliative and eventually every patient will be confronted with recurrence of disease and drug resistance. Previously, microRNAs have been shown to be involved in drug response in MPM cells. To better understand the role of microRNAs in the phenomenon of drug resistance in MPM and to identify microRNAs able to sensitise MPM cells to chemotherapy, we adopted and modified a three-dimensional (3D) spheroid cell culture model.
Methods:
We profiled microRNA gene expression in 3D spheroids and standard 2D cell culture. TaqMan-based qPCR and digital PCR were used for validation. Drug cytotoxicity was investigated in both 2D and 3D culture. Candidate genes were selected for their effect on drug resistance in both cultures using microRNA mimics.
Results:
We confirmed that MPM cells grown as 3D spheroids were more resistant to the conventional chemotherapeutics cisplatin and gemcitabine as compared to the same cells grown in standard 2D culture. We identified significant upregulation of miR-210-3p, miR-378a-3p, miR-195-5p and miR-146b-5p, and down-regulation of miR-320b and miR-1225b-5p in 3D spheroids. Transfecting MPM cells grown in 2D culture with a miR-210 mimic resulted in increased drug resistance, thus implicating its involvement as an onco-miR in MPM.
Conclusion:
We demonstrated the possibility of using miR-210 to re-sensitise MPM cells to chemotherapy. This may be utilised as a potential therapeutic approach in a clinical setting.