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MA02 - RNA in Lung Cancer (ID 377)
- Event: WCLC 2016
- Type: Mini Oral Session
- Track: Biology/Pathology
- Presentations: 1
MA02.02 - A Novel 5-miR Signature Shows Promise as a Diagnostic Tool and as a Predictor of Cisplatin Response in NSCLC (ID 5948)
14:20 - 15:50 | Author(s): V. Young
MicroRNAs are a class of small non-coding RNAs that range in size from 19-25 nucleotides. They have been shown to regulate a number of processes within tumour biology, including metastasis, invasion and angiogenesis. More recently, miRNAs have been linked to chemoresistance in solid tumours, including lung cancer.
MicroRNA expression within an isogenic panel of age-matched parent (PT) and cisplatin resistant (CisR) NSCLC cell lines was profiled using the 7[th] generation miRCURY LNA arrays (Exiqon). Significantly altered miRNAs within the CisR sublines were manipulated using antagomirs (Exiqon) and Pre-miRs (Ambion) and functional studies were carried out in the presence and absence of cisplatin. To examine the translational relevance of these miRNAs, their expression was examined in a cohort of chemo-naïve patient-matched normal and lung tumour tissue and serum from NSCLC patients of different histologies. To create a xenograft model of cisplatin resistance 1x10[3 ]cells H460 PT or CisR cells were injected into 5-7week old NOD/SCID mice. Tumour volume was measured over time and harvested once the tumour mass measured 500mm and formalin-fixed and paraffin embedded (FFPE). Expression of the 5-miR signature was analysed within FFPE murine tumours and cisplatin resistance was investigated relative to cisplatin sensitive controls.
Profiling and subsequent validation revealed a 5-miR signature associated with our model of cisplatin resistance (miR-30a-3p, miR-30b-5p, miR-30c-5p, miR-34a-5p, miR-4286). Inhibition of the miR-30 family and miR-34a-5p reduced clonogenic survival of CisR cells when treated cisplatin. Expression of the miRNA signature was significantly altered in both adenocarcinoma (AD) and squamous cell carcinoma (SCC) relative to matched normal lung tissue and between SCC and AD tissue. miR-4286 was significantly up-regulated in SCC sera compared to normal control and AD sera. Similarly to the cell line expression of the miRNAs, the miR-30 family members and miR-34a-5p were up-regulated in the CisR xenograft FFPE tissue relative to PT.
A novel miRNA signature associated with cisplatin resistance was identified in vitro, genetic manipulation of which altered clonogenic response to cisplatin. The 5-miR signature shows both diagnostic and prognostic biomarker potential across a number of diagnostically relevant biological mediums.
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P1.05 - Poster Session with Presenters Present (ID 457)
- Event: WCLC 2016
- Type: Poster Presenters Present
- Track: Early Stage NSCLC
- Presentations: 1
- Coordinates: 12/05/2016, 14:30 - 15:45, Hall B (Poster Area)
P1.05-021 - circRNAs: Potential Novel Biomarkers for the Early Detection of Lung Cancer (ID 5020)
14:30 - 15:45 | Author(s): V. Young
Lung cancer is the leading cancer killer globally. Cancers such as colon, breast, and prostate all have relatively reliable early detection tests. In contrast, lung cancer does not. If caught early, lung cancer has a much better prognosis. Non-invasive or minimally invasive tools to improve early detection of lung cancer represents a critical unmet need. Analysis of the human transcriptome indicates that a mere 2% of the genome corresponds to protein coding transcripts, yet ~ 75% of the genome is transcribed. It is now well established that these non-coding RNAs (ncRNAs) play important regulatory functions within the cell and their expression are often altered in cancer. Circular RNAs (circRNAs) are a species of ncRNAs. They are abundant, conserved and demonstrate cell-type specific expression patterns. Moreover, they are extremely stable with half-life’s greater than 48 hours, are resistant to degradation by RNA exonucleases, and have been shown to play important roles in cancer. Taken together these suggest that circRNAs could potentially be important biomarkers in early lung cancer diagnosis.
Total RNAs isolated from a panel of matched normal/tumour NSCLC adenocarcinoma (Stage IA/IB) samples (n=6) were probed for circRNAs using the Arraystar circRNA microarray. Survival was assessed on linear mRNAs with associated circRNAs using KM-Plot.
Interim analysis of the data has identified n=206 circRNAs with a 2-fold difference in expression between their matched normal vs. tumour counterparts. Principal Component Analysis (PCA) demonstrated a clear separation of the samples (Tumour vs. Normal). Self-Organizing Maps (SOMs) analysis generated distinctive SOMS clusters of circRNAs, while associated linear pathway enrichment for microRNA and transcriptional binding motifs identified several additional potential networks. Moreover, an analysis of linear mRNAs associated with 10 circRNAs with altered expression in adenocarcinomas found that these mRNAs were linked to overall survival, and that the majority were adenocarcinoma specific.
Altered levels of a number of circRNAs were associated with lung adenocarcinoma. A separate cohort of squamous cell carcinomas is currently being assessed for circRNAs. At present we are validating the expression of these circRNAs in a larger cohort of specimens, and assessing whether or not these are detectable in plasma/serum from the same individuals. Overall, circRNAs may represent novel potential biomarkers for the detection of NSCLC, and may provide additional critical basic knowledge regarding the development and biology of NSCLC.