Background: Aberrant expression of long noncoding RNAs (lncRNAs) is associated with the progression of human cancers, including gastric cancer (GC). The function of lncRNA DLGAP1-AS2, as an oncogene, has been identi ed in glioma, hepatocellular carcinoma, and cholangiocarcinoma but not in other malignancies. Therefore, this study was aimed to explore the association of DLGAP1-AS2 with gastric tumorigenesis and beyond.Methods and Results: The expression level of DLGAP1-AS2 was prevaluated in GC datasets from Gene Expression Omnibus (GEO). Moreover, qRT-PCR experiment was performed on 25 paired GC and adjacent normal tissue samples. The Cancer Genome Atlas (TCGA) data were also analyzed for further validations. Consistent with data obtained from GEO datasets, qRT-PCR results revealed that DLGAP1-AS2 was signi cantly (p < 0.0032) upregulated in GC specimens compared to normal samples, which was additionally con rmed using TCGA analysis (p<0.0001). DLGAP1-AS2 expression level was also correlated with age (p =0.0008), lymphatic and vascular invasion (p =0.0415) in internal samples. Also, a signi cant correlation was found between DLGAP1-AS2 and YAP1 expression, as its valid downstream target, in GC samples. Besides, analysis of other prevalent tumor entities using TCGA illustrated the signi cant overexpression of DLGAP1-AS2 in lung, colorectal, and prostate cancers, further indicating its promise as an oncogene. Moreover, ROC curve analysis showed the high accuracy of the DLGAP1-AS2 expression pattern as a diagnostic biomarker for gastric and colorectal cancers. Conclusion: Our ndings indicated that DLGAP1-AS2 might display oncogenic property in gastric tumorigenesis and be suggested as a therapeutic and diagnostic target.

Background: Aberrant expression of long noncoding RNAs (lncRNAs) is associated with the progression of human cancers, including gastric cancer (GC). The function of lncRNA DLGAP1-AS2, as an oncogene, has been identified in glioma, hepatocellular carcinoma, and cholangiocarcinoma but not in other malignancies. Therefore, this study was aimed to explore the association of DLGAP1-AS2 with gastric tumorigenesis and beyond.Methods and Results: The expression level of DLGAP1-AS2 was prevaluated in GC datasets from Gene Expression Omnibus (GEO). Moreover, qRT-PCR experiment was performed on 25 paired GC and adjacent normal tissue samples. The Cancer Genome Atlas (TCGA) data were also analyzed for further validations. Consistent with data obtained from GEO datasets, qRT-PCR results revealed that DLGAP1-AS2 was significantly (p < 0.0032) upregulated in GC specimens compared to normal samples, which was additionally confirmed using TCGA analysis (p<0.0001). DLGAP1-AS2 expression level was also correlated with age (p =0.0008), lymphatic and vascular invasion (p =0.0415) in internal samples. Also, a significant correlation was found between DLGAP1-AS2 and YAP1 expression, as its valid downstream target, in GC samples. Besides, analysis of other prevalent tumor entities using TCGA illustrated the significant overexpression of DLGAP1-AS2 in lung, colorectal, and prostate cancers, further indicating its promise as an oncogene. Moreover, ROC curve analysis showed the high accuracy of the DLGAP1-AS2 expression pattern as a diagnostic biomarker for gastric and colorectal cancers. Conclusion: Our findings indicated that DLGAP1-AS2 might display oncogenic property in gastric tumorigenesis and be suggested as a therapeutic and diagnostic target.