title: Clinical evaluation of microRNA expression profiling in non small cell lung cancer.
abstract: Deregulation of miRNAs expression levels has been detected in many human tumor types, and recent studies have demonstrated the critical roles of miRNAs in cancer pathogenesis. Numerous recent studies have shown that miRNAs are rapidly released from tissues into the circulation in many pathological conditions. The high relative stability of miRNAs in biofluids such as plasma and serum, and the ability of miRNA expression profiles to accurately classify discrete tissue types and disease states have positioned miRNAs as promising non-invasive new tumor biomarkers. In this study, we used liquid bead array technology (Luminex) to profile the expression of 320 mature miRNAs in a pilot testing group of 19 matched fresh frozen cancerous and non-cancerous tissues from NSCLC patients. We further validated our results by RT-qPCR for differentially expressed miRNAs in an independent group of 40 matched fresh frozen tissues, 37 plasma samples from NSCLC patients and 28 healthy donors. We found that eight miRNAs (miR-21, miR-30d, miR-451, miR-10a, miR-30e-5p and miR-126*, miR-126, miR-145) were differentially expressed by three different statistical analysis approaches. Two of them (miR-10a and miR-30e-5p) are reported here for the first time. Bead-array results were further verified in an independent group of 40 matched fresh frozen tissues by RT-qPCR. According to RT-qPCR miR-21 was significantly up-regulated (P = 0.010), miR-126* (P = 0.002), miR-30d (P = 0.012), miR-30e-5p (P < 0.001) and miR-451 (P < 0.001) were down-regulated, while miR-10a was not differentiated (P = 0.732) in NSCLC tissues. However, in NSCLC plasma samples, only three of these miRNAs (miR-21, miR-10a, and miR-30e-5p) displayed differential expression when compared to plasma of healthy donors. High expression of miR-21 was associated with DFI and OS both in NSCLC tissues (P = 0.022 and P = 0.037) and plasma (P = 0.045 and P = 0.065), respectively. Moreover, we report for the first time that low expression of miR-10a in NSCLC plasma samples was associated with worse DFI (P = 0.050) and high expression of miR-30e-5p was found to be associated with shorter OS (P = 0.048). In conclusion, circulating miR-21, miR-10a and miR-30e-5p in plasma should be further evaluated as potential non-invasive biomarkers in NSCLC.
authors.affiliation: Laboratory of Analytical Chemistry, Department of Chemistry, University of Athens, Athens, Greece.
authors.forename: A
authors.initials: A
authors.lastname: Markou
authors.affiliation: Laboratory of Analytical Chemistry, Department of Chemistry, University of Athens, Athens, Greece.
authors.forename: I
authors.initials: I
authors.lastname: Sourvinou
authors.affiliation: Laboratory of Analytical Chemistry, Department of Chemistry, University of Athens, Athens, Greece.
authors.forename: P A
authors.initials: PA
authors.lastname: Vorkas
authors.affiliation: Department of Laboratory Medicine, and the Keenan Research Centre in the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Canada.
authors.forename: G M
authors.initials: GM
authors.lastname: Yousef
authors.affiliation: Laboratory of Analytical Chemistry, Department of Chemistry, University of Athens, Athens, Greece. Electronic address: lianidou@chem.uoa.gr.
authors.forename: E
authors.initials: E
authors.lastname: Lianidou
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000235:genetics; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis / Q000235:genetics* / Q000401:mortality; D016000:Cluster Analysis; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D053263:Gene Regulatory Networks; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis / Q000235:genetics* / Q000401:mortality; D008297:Male; D035683:MicroRNAs / Q000097:blood / Q000235:genetics*; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D015203:Reproducibility of Results; D012307:Risk Factors
chemical_list: D014408:Biomarkers, Tumor; D035683:MicroRNAs
keywords: AD; Circulating miRNAs; DFI; LNA; Liquid bead array; MicroRNAs; NSCLC; Non small cell lung cancer; OS; RT-qPCR; SCC; Tumor markers; adenocarcinoma; disease free interval; locked nucleic acid; miR-21; miRNAs; microRNAs; non small cell lung cancer; overall survival; quantitative reverse transcription PCR; squamous cell carcinoma