Real-time quantitative PCR analysis of human malignant pleural mesothelioma tissue specimens. Homo sapiens

BACKGROUND: Malignant pleural mesothelioma (MPM) is difficult to distinguish from reactive mesothelial proliferations (RMPs). MicroRNAs (miRNAs) are small non-coding RNA-strands (~22 nucleotides) that post-transcriptionally regulate gene-expression. Studies have shown that miRNAs are potential diagnostic markers in other cancers; however, it is uncertain whether miRNAs are useful biomarkers for differentiating MPM from RMP. OBJECTIVE: To identify differentially expressed microRNAs which can aid in the diagnostics of MPM. METHODS: We screened with a quantitative RT-PCR (RT-qPCR)-based platform the expression of 742 miRNAs in formalin-fixed paraffin-embedded (FFPE) preoperative diagnostic biopsies, surgically resected MPM-specimens previously treated with chemotherapy, and corresponding non-neoplastic pleura (NNP) from 5 patients. RESULTS: By comparing the change in microRNA expression in patient-matched tissue samples, we identify 14 miRNAs which exhibit statistically significant deregulation between sample groups. CONCLUSION: Based on this initial screening of miRNA expression, we have identified 14 miRNAs which are potential diagnostic biomarkers and may aid in diffferentiating RMP from MPM. Overall design: qPCR microRNA expression profiling. MicroRNA expression in surgical tissue samples and presurgery diagnostic biopsies of malignant pleural mesotheliomas was compared to corresponding patient-matched non-neoplastic pleura. Patient-matched diagnostic biopsies from still chemotherapy-naïve patients were included to test for chemotherapy-induced changes in microRNA expression.