Genomic instability-associated lncRNA signature predicts prognosis and distinct immune landscape in gastric cancer

BACKGROUND: Characterized by multiple features, genomic stability-related markers, such as microsatellite instability (MSI), were regulated as an important predictor of chemotherapy and immunity responses in cancer treatment. The aim of our study was to identify a genomic instability-associated long non-coding RNA (lncRNA) signature to help predict the survival and therapy response of gastric cancers (GCs). METHODS: We used RNA sequencing and single nucleotide variant (SNV) data from The Cancer Genome Atlas-stomach adenocarcinoma (TCGA-STAD) datasets to explore genomic instability-associated lncRNAs. Hierarchical cluster analyses of 197 differentially expressed genomic instability-associated lncRNAs were performed to separate GC patients into two groups, namely, the genomically unstable (GU)-like group and the genomically stable (GS)-like group. RESULTS: Cox regression analysis was conducted to finally identify six lncRNAs (LINC02678, HOXA10-AS, RHOXF1-AS1, AC010789.1, LINC01150, and TGFB2-AS1) with independent prognostic value to establish the genomic instability-associated lncRNA signature (GILncSig). Based on the SNV analysis, GILncSig was correlated with accumulation of gene mutation counts. Further comparisons between different risk score groups were performed to assess chemotherapy drug sensitivity and immune landscape variations. CONCLUSIONS: Our study not only revealed the genomic instability-associated lncRNAs in GCs, but provided a key method and resource for further studies of the role of these lncRNAs play, and introduced a potential new way to identify genomic instability-associated cancer biomarkers.