The Somatic Mutation Landscape and RNA Prognostic Markers in Stomach Adenocarcinoma

Purpose: Stomach cancer is one of the highest incidence and mortality malignancies worldwide. Our study aimed to illustrate the somatic mutation landscape and identify molecular markers of stomach cancer. Materials and Methods: By integrated analysis of sequencing data and clinical data of stomach adenocarcinoma (STAD) from The Cancer Genome Atlas (TCGA) database, we identified several susceptibility genes and novel molecular markers and validated their potential function by the starBase website. Further, we validated the clinical value of two candidate lncRNAs in collected STAD samples by RT-qPCR. Results: We illustrated the distributions of mutation frequencies and types to get the top 20 high-mutation frequency genes in STAD. We also found 2127 mRNAs, 129 miRNAs, and 170 lncRNAs that were differentially expressed. We identified four IncRNA-miRNA-mRNA ceRNAs (PVT1, MAGI2-A53, MIR17HG, KCNQ1OT1). Besides, 27 mRNAs (PDE4C, ID1, AQP3, VCAN, FAR NOX4, ANGPT2, SERPINEE SPARC, PDGFRB, FN1, MFAP2, CSMD2, INHBA, COL10A1, MATN3, P4HA3, ADAMTS12, DGKI, OLFML2B, TMEM200A, FNDC1, CTIARCE CHST1, F5, COL5A2, TUBB3) and two lncRNAs (M1R4458HG, LINC01235) showed a significant prognostic value, and their prognostic values were validated by the starBase website. What's more, the clinical values of MIR4458HG and LINC01235 were also demonstrated in collected STAD samples. Conclusion: We constructed the lncRNA ceRNA networks and identified 20 high-mutation frequency genes and 29 prognostic markers (27 mRNAs and two lncRNAs).