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N. Van Zandwijk
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MINI 24 - Epidemiology, Early Detection, Biology (ID 140)
- Event: WCLC 2015
- Type: Mini Oral
- Track: Thymoma, Mesothelioma and Other Thoracic Malignancies
- Presentations: 1
- Moderators:J. Creaney, M. Carbone
- Coordinates: 9/08/2015, 16:45 - 18:15, 102+104+106
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MINI24.09 - Cell-Free MicroRNA miR-625-3p Is Elevated in the Blood of Patients with Thoracic Malignancies (ID 1282)
16:45 - 18:15 | Author(s): N. Van Zandwijk
- Abstract
Background:
In most instances definitive diagnosis of malignant pleural mesothelioma (MPM) requires a tissue biopsy of sufficient size. As a biopsy is not always feasible, the identification of an accurate biomarker easily measured in blood would represent an important step forward. A recent study indicated that microRNA miR-625-3p was present in elevated concentration in plasma or serum of MPM patients compared to healthy controls and asbestosis patients. (Kirschner et al, JTO; 7:1184). In this study, we have further investigated the diagnostic potential of miR-625-3p.
Methods:
MiR-625-3p and other microRNAs were measured by RT-qPCR in two independent series of MPM patients and controls. After exclusion of haemolysed samples and those yielding RNA of insufficient quality, series 1 consisted of serum samples from 73 MPM patients, 69 healthy volunteers and 64 patients with non-small cell lung cancer (NSCLC) collected at the Netherlands Cancer Institute (NKI) between 1994 and 2013. The second series consisted of plasma samples from 29 MPM patients and 35 healthy volunteers collected in Vienna and Hungary (V/H) between 2011 and 2013. Additionally levels of soluble mesothelin-related protein (SMRP) were assessed (ELISA) in the NKI series.
Results:
Analyses of samples from patients and controls in the NKI series revealed that serum miR-625-3p concentrations were on average 5.35-fold higher (p=0.0054) in MPM, and 3.47-fold (p=0.003) in NSCLC than in control samples. Levels in MPM patients were 1.54-fold higher than in NSCLC patients but this did not reach statistical significance (p=0.273). Compared to healthy controls, the areas under the ROC curve (AUC) were 0.82 (95% CI: 0.75-0.89) for MPM and 0.75 (95% CI: 0.67-0.84) for NSCLC. In the samples of the V/H series, plasma miR-625-3p concentrations were on average 1.98-fold (p<0.001) higher in MPM patients than in healthy volunteers, with an AUC of 0.80 (95% CI: 0.69-0.91). Assessment of SMRP in the NKI series revealed AUCs of 0.69 (95% CI: 0.59-0.78) differentiating MPM from healthy individuals and 0.65 (95% CI: 0.54-0.75) separating MPM from NSCLC, comparable to AUC values reported earlier.
Conclusion:
Data from two independent validation series confirms the previously observed increased abundance of miR-625-3p in blood from MPM patients. However, the miR-625-3p levels observed in NSCLC patients show that elevation of the level of this microRNA in plasma/serum is not restricted to MPM. Further studies into combinations of microRNAs and SMRP (diagnostic signature) in MPM are warranted.
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P1.01 - Poster Session/ Treatment of Advanced Diseases – NSCLC (ID 206)
- Event: WCLC 2015
- Type: Poster
- Track: Treatment of Advanced Diseases - NSCLC
- Presentations: 1
- Moderators:
- Coordinates: 9/07/2015, 09:30 - 17:00, Exhibit Hall (Hall B+C)
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P1.01-072 - Targeted Delivery of a Synthetic microRNA-Based Mimic to Treat Thoracic Cancers (ID 2911)
09:30 - 17:00 | Author(s): N. Van Zandwijk
- Abstract
Background:
MicroRNA expression is commonly suppressed in cancer, contributing to tumor cell biology. Recently we demonstrated that multiple members of the miR-15/16 family are downregulated and have tumor suppressor functions in malignant pleural mesothelioma (MPM), an asbestos-related cancer for which few treatments are available. These results are similar to previous findings in non-small cell lung cancer (NSCLC). As multiple microRNAs from the same family are downregulated in MPM, we investigated whether a single synthetic mimic based on the consensus sequence of the entire family could restore activity of the entire family.
Methods:
Novel microRNA mimics based on the consensus sequence of the miR-15/107 group were designed (con15/107.1 to 4). The effects on growth, migration, target regulation, drug sensitivity and angiogenesis of the con15/107 mimics were compared with native miR-15 and miR-16 mimics using standard assays in MPM and lung cancer cell lines in vitro. The regulation of specific target genes was assessed by RT-qPCR, Western blot and luciferase reporter assays. Global gene regulation was assessed by proteomics. Activity of con15/107 mimics was investigated in vivo in xenograft models in nude mice.
Results:
The consensus mimics inhibited growth and migration of MPM and lung cancer cell lines in vitro, and effects were greater than with native miR-15 or miR-16 mimics. Growth inhibition was associated with an induction of apoptosis, and downregulation of predicted targets of the mimics. Target gene interactions were confirmed with 3’UTR reporter constructs, and proteomics identified a number of candidate genes involved in consensus mimic-induced growth inhibition. Consensus mimics also sensitized multiple MPM and lung cancer cell lines to chemotherapy agents, and inhibited angiogenic activity in endothelial cells. In a xenograft model, the consensus mimic con15/107.2, packaged in bacterially-derived, EGFR antibody-targeted, EDV[TM]nanocells, inhibited MPM tumor growth in vivo.
Conclusion:
The novel con15/107 mimics based on the consensus sequence of the miR-15/107 group have greater activity than native miR-15 or miR-16 mimics in vitro and are active in vivo. Increased activity correlates to greater target gene downregulation. These preclinical studies support a Phase I clinical trial has been initiated for patients with MPM or NSCLC failing standard therapy. This represents the first trial of microRNA replacement as a therapy for thoracic cancer.
