177PD - Exosomal long non-coding RNA (LNCRNA) in lung cancer

Date 01 October 2012
Event ESMO Congress 2012
Session Basic Science and Translational Research II
Topics Basic Science
Lung and other Thoracic Tumours
Presenter Goetz Kloecker
Authors G. Kloecker1, C. Taylor2, N. Vinayek1, D. Taylor2
  • 1Dept. Medical Oncology & Hematology, Brown Cancer Center University of Louisville, 40205 - Louisville/US
  • 2Department Of Ob/gyn, University of Louisville, Louisville/US

Abstract

Background

Long noncoding RNAs (lncRNAs) are master regulators of pluripotency, differentiation, body axis patterning and promoting developmental transitions. Dysregulation of lncRNA expression has been shown to be associated with a wide range of pathologies.

Study Design

lncRNA within exosomes of lung cancer cell line (H838) and derived from patients with NSCLC were analyzed. After 10,000xg centifugation, microvesicles were isolated by chromatography (CT). Trizol isolated total RNA, which was analyzed for specific lncRNAs using the LncRNA profiler qPCR array (Systems Biosciences). RNA and ln RNA from tumor cells and the vesicles from NSCLC patient (n = 8) sera were analyzed the same way.

Results

Microvesicles' size, 50-200nm, was consistent with exosomes (CD63 confirmed). Exosomes contained RNA and lncRNA. Comparison of lncRNA between tumor cells and their released exosomes revealed selectivity on the lncRNAs appearing in the exosomes. Three of 90 examined lncRNAs had a 10-fold increase within exosomes. Representative lncRNAs were compared between the cells and their released exosomes. For lncRNAs exhibiting epigenetic silencing, splicing regulation, regulating apoptosis and translational control the CT values of lncRNA within cells and the lncRNA within exosomes were the same (ANRIL cells 23.80 vs. 26.44 exosomes. MALAT-1 cells 31.84 vs. 32.85 exosomes. BACE1AS cells 34.14 vs 34.86 exosomes). The lncRNA profiles of cancer patients were distinct from normal.An increase of greater than 20-fold was observed in 58 lncRNAs in cancer patient-derived exosomes. In contrast, a decrease of 10-fold or greater was observed in 20 lncRNAs in cancer patients. LncRNAs exhibiting epigenetic silencing, In lncRNAs exhibiting splicing regulation and lncRNAs regulating apoptosis,were elevated 20-40 fold in cancer patient-derived exosomes versus controls. Conclusions: Misexpression of lncRNAs contributes to cancer development and progression. Cancer patients' exosomes contain lncRNA distinct from non-cancer controls.Some lncRNAs, such as MALAT-1 (metastasis-associated in lung adenocarcinoma transcript) were identified in serum of NSCLC patients. The stability of exosomes in the peripheral circulation and the unique profile of lncRNAs suggest their ideal utility as a diagnostic biomarker.

Disclosure

All authors have declared no conflicts of interest.