Background. Biglycan (BGN) is a family member of small leucine-rich repeat proteoglycans. High expression of BGN might enhance the invasion and metastasis in some types of tumors. Here, the prognostic significance of BGN was evaluated in gastric cancer. Material and Methods. Two independent Gene Expression Omnibus (GEO) gastric cancer microarray datasets ( and ) were collected for this study. Kaplan-Meier analysis was applied to evaluate if BGN impacts the outcomes of gastric cancer. Protein-protein interaction (PPI) analysis was performed on gastric cancer-related genes and BGN targets, and those interactions with were chosen to construct a PPI network. The gene set enrichment analysis (GSEA) was used to explore BGN and cancer-related gene signatures. Gene Transcription Regulation Database (GTRD) and ALGGEN-PROMO predicted the transcription factor binding sites (TFBSs) of the BGN promoter. BGN protein level in gastric cancer tissue was determined by immunohistochemistry (IHC). Bioinformatic analysis predicted the putative TFs of BGN. Results. For gastric cancer, the mRNA expression level of BGN in tumor tissue was significantly higher than that in normal tissue. Kaplan-Meier analysis showed that higher expression of BGN mRNA was significantly associated with more reduced recurrence-free survival (RFS). GSEA results suggested that BGN was significantly enriched in gene signatures related to metastasis and poor prognosis, revealing that BGN might be associated with cell proliferation, poor differentiation, and high invasiveness of gastric cancer. Meanwhile, the putative TFs, including AR, E2F1, and TCF4, were predicted by bioinformatic analysis and also significantly correlated with expression of BGN in mRNA levels. Conclusion. High expression of BGN mRNA was significantly related to poor prognosis, which suggested that BGN was a potential prognostic biomarker and therapeutic target of gastric cancer.

中文翻译：

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Biglycan在胃癌中的表达及预后价值

背景。Biglycan (BGN) 是富含亮氨酸的小重复蛋白聚糖的家族成员。BGN的高表达可能增强某些类型肿瘤的侵袭和转移。在这里，评估了 BGN 在胃癌中的预后意义。材料和方法。两个独立的基因表达综合（GEO）胃癌微阵列数据集（和)为本研究收集。Kaplan-Meier 分析用于评估 BGN 是否影响胃癌的结果。对胃癌相关基因和 BGN 靶标进行蛋白质-蛋白质相互作用 (PPI) 分析，这些相互作用与被选为构建 PPI 网络。基因集富集分析 (GSEA) 用于探索 BGN 和癌症相关的基因特征。基因转录调控数据库 (GTRD) 和 ALGGEN-PROMO 预测了 BGN 启动子的转录因子结合位点 (TFBS)。通过免疫组织化学（IHC）测定胃癌组织中的BGN蛋白水平。生物信息学分析预测了 BGN 的推定 TF。结果. 对于胃癌，肿瘤组织中BGN的mRNA表达水平明显高于正常组织。Kaplan-Meier 分析表明，BGN mRNA 的较高表达与无复发生存期 (RFS) 的降低显着相关。GSEA结果表明BGN显着富集与转移和预后不良相关的基因特征，表明BGN可能与胃癌的细胞增殖、分化差和高侵袭性有关。同时，推定的 TF，包括 AR、E2F1 和 TCF4，通过生物信息学分析预测，并且与 BGN 在 mRNA 水平的表达显着相关。结论. BGN mRNA的高表达与不良预后显着相关，提示BGN是胃癌潜在的预后生物标志物和治疗靶点。