Development of lncRNAs expression signatures in exosomes derived from different gastric cancer cells

Exosomes from the culture media (CM) of four GC cells (GCCs) and human gastric epithelial cells were isolated. Exosomal RNA was extracted, and lncRNA microarray assay was performed to identify GC-specific exosomal lncRNAs. A total of 199 exosomal lncRNAs were expressed at considerable higher levels in GCCs than those in normal controls, among which the top 10 upregulated lncRNAs were selected for further validation. qRT-PCR revealed that lnc-SLC2A12-10:1 was remarkably upregulated in exosomes derived from patients with GC and GCCs. The expression levels of the candidate exosomal lncRNAs lnc-SLC2A12-10:1 were validated in 120 subjects via quantitative reverse transcription PCR (qRT-PCR).The result suggested that exosomal lnc-SLC2A12-10:1 may be a potential noninvasive biomarker for the diagnosis and prognosis monitoring of GC. Four human GCC lines (MGC803, BGC823, SGC7901, and AGS) and one normal human gastric (GES-1) cell line were cultured at 37 °C with 5% CO2 in 1640/DMEM containing 10% exosome-depleted FBS. Exosomal RNA from the CM of four GCCs and GES-1 were purified, five independent samples were collected and lncRNA microarray assay was conducted to identify GC-specific exosomal lncRNAs.