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Background: Gastric cancer (GC) accounts for high mortality. RNA methylation has recently gained interest as markers in specific tumors. This study aimed to uncover the function of the roles of 25 RNA methylation regulators in GC. Methods: RNA sequence and clinical data were downloaded from The Cancer Genome Atlas (TCGA) database. "STRING" and R were performed to analyze the correlation among the methylase. COX and LASSO were performed to screen for prognostic associated RNA methylation regulators. A prognostic model was established based on the expression of methylase. RT-PCR and immunohistochemistry detected the expression of methylase in GC cells and tissue. Kaplan–Meier curve and Cox analysis were applied to evaluate the effectiveness of the model. Results: The prediction model was established based on the expression of m6A RNA methylation regulators FTO (fat mass and obesity-associated) and RBM15 (RNA binding motif protein 15). Based on the model, GC patients were divided into "high risk" and "low risk" groups to compare the differences in survival. The model was re-evaluated with the clinical data of our center. Conclusion: The two-methylase combination model was an independent prognostic factor of GC. [ABSTRACT FROM AUTHOR]

Background: To investigate the clinical significance of ubiquitin-specific peptidase 19 (USP19) expression in gastric cancer (GC) compared with that in normal tissues and gastric cell lines. Methods: USP19 protein expression was analyzed in 212 paired GC samples using immunohistochemical staining. Quantitative real-time PCR (qRT-PCR) and Western blotting were used to detect the level of USP19 in gastric cell lines. The biological functions of USP19 were investigated by MTT assay, colony-forming assay, wound healing assay and gelatin zymography, and apoptotic cells were detected by immunohistochemistry assays in SGC7901 xenograft models. Results: USP19 expression was significantly increased in GC cells and tissues, and the high level of USP19 expression was positively correlated with the Lauren's classification and poor prognosis. Moreover, USP19 was identified as a novel independent prognostic biomarker in GC patients. Enhanced USP19 expression promoted GC cell proliferation and metastasis through reduced cleaved caspase-3 and increased MMP2/MMP9 expression and promoted enzyme activity in the study, and verified the results through The Cancer Genome Atlas (TCGA) and bioinformatic websites from the Kaplan–Meier plotter (http://kmplot.com) and GEPIA (http://gepia2.cancer-pku.cn.). Conclusion: Our study suggests that USP19 promoted tumor progression by inducing MMP2/MMP9 expression and related enzyme activity. Hence, USP19 may be a valuable prognostic predictor for GC, and the USP19-MMP2/MMP9 axis could serve as a therapeutic target. [ABSTRACT FROM AUTHOR]

Background: Luminal subtype breast cancer accounts for a predominant number of breast cancers. Considering the heterogeneity of the disease, it is urgent to develop novel biomarkers to improve risk stratification and optimize therapy choices. Long non-coding RNA (lncRNA) represents an emerging and understudied class of transcripts that play a significant role in cancer biology. Growing knowledge of cancer-associated lncRNAs contributes to the development of molecular markers for prognosis evaluation and gene therapy. Materials and methods: Three pairs of primary luminal subtype breast cancer tissues and adjacent non-cancerous tissues were collected and sequenced. EBseq algorithm was used to identify differentially expressed lncRNAs. RNA sequencing data from The Cancer Genome Atlas (TCGA) database were used to validate the robustness of our RNA-seq results. Kaplan-Meier and Cox regression analyses were utilized to assess the association between the lncRNAs and overall survival of patients in TCGA cohort. Results: A total of 796 lncRNAs were significantly dysregulated in luminal subtype breast cancer, including 436 upregulated and 360 downregulated lncRNAs. Among them, FAM83H antisense RNA 1 (FAM83H-AS1) was the most upregulated lncRNA, whereas GSN antisense RNA 1 (GSN-AS1) was the most downregulated lncRNA. Moreover, we proved that the high expression level of FAM83H-AS1 indicated unfavorable prognosis not only in luminal subtype breast cancer but also in all subtype breast cancers. To the best of our knowledge, this is the first report indicating that FAM83H-AS1 was involved in luminal subtype breast cancer and was an independent prognostic indicator. Conclusion: Our study provides a rich resource to the research community for further identifying lncRNAs with diagnostic and therapeutic potentials and exploring biological function of lncRNAs in luminal subtype breast cancer. [ABSTRACT FROM AUTHOR]