BACKGROUND Accumulation evidence indicates the vital role of long non-coding RNAs (lncRNAs) in tumorigenesis and the progression of malignant tumors, including pancreatic cancer (PC). However, the role and the molecular mechanism of long non-coding RNA 00976 is unclear in pancreatic cancer. METHODS In situ hybridization (ISH) and qRT-PCR was performed to investigate the association between linc00976 expression and the clinicopathological characteristics and prognosis of patients with PC. Subsequently, linc00976 over-expression vector and shRNAs were transfected into PC cells to up-regulate or down-regulate linc00976 expression. Loss- and gain-of function assays were performed to investigate the role of linc00976 in proliferation and metastasis in vitro and vivo. ITRAQ, bioinformatic analysis and rescue assay were used to illustrate the ceRNA mechanism network of linc00976/miR-137/OTUD7B and its downstream EGFR/MAPK signaling pathway. RESULTS linc00976 expression was overexpressed in PC tissues and cell lines and was positively associated with poorer survival in patients with PC. Function studies revealed that linc00976 knockdown significantly suppressed cell proliferation, migration and invasion in vivo and in vitro, whereas its overexpression reversed these effects. Based on Itraq results and online database prediction, Ovarian tumor proteases OTUD7B was found as a downstream gene of linc00976, which deubiquitinated EGFR mediates MAPK signaling activation. Furthermore, Bioinformatics analysis and luciferase assays and rescue experiments revealed that linc00976/miR137/OTUD7B established the ceRNA network modulating PC cell proliferation and tumor growth. CONCLUSION The present study demonstrates that linc00976 enhances the proliferation and invasion ability of PC cells by upregulating OTUD7B expression, which was a target of miR-137. Ultimately, OTUD7B mediates EGFR and MAPK signaling pathway, suggesting that linc00976/miR-137/OTUD7B/EGFR axis may act as a potential biomarker and therapeutic target for PC.

中文翻译：

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长非编码RNA 00976通过使涉及EGFR / MAPK途径的miR-137海绵化，通过OTUD7B促进胰腺癌的进展。

背景技术积累的证据表明，长非编码RNA（lncRNA）在肿瘤发生和恶性肿瘤（包括胰腺癌（PC））的进展中起着至关重要的作用。但是，长非编码RNA 00976在胰腺癌中的作用和分子机制尚不清楚。方法采用原位杂交（ISH）和qRT-PCR技术检测linc00976表达与PC患者临床病理特征及预后的关系。随后，将linc00976过表达载体和shRNA转染到PC细胞中，以上调或下调linc00976的表达。进行功能丧失和获得功能分析以研究linc00976在体外和体内增殖和转移中的作用。ITRAQ，通过生物信息学分析和挽救分析来阐明linc00976 / miR-137 / OTUD7B的ceRNA机制网络及其下游EGFR / MAPK信号通路。结果linc00976表达在PC组织和细胞系中过表达，并且与PC患者生存较弱呈正相关。功能研究表明，linc00976敲低显着抑制了体内和体外的细胞增殖，迁移和侵袭，而其过表达则逆转了这些作用。根据Itraq结果和在线数据库预测，发现卵巢肿瘤蛋白酶OTUD7B是linc00976的下游基因，其去泛素化EGFR介导MAPK信号激活。此外，生物信息学分析，荧光素酶测定和救援实验表明，linc00976 / miR137 / OTUD7B建立了调节PC细胞增殖和肿瘤生长的ceRNA网络。结论本研究表明，linc00976通过上调OTUD7B表达（其是miR-137的靶标）来增强PC细胞的增殖和侵袭能力。最终，OTUD7B介导EGFR和MAPK信号传导途径，表明linc00976 / miR-137 / OTUD7B / EGFR轴可能充当PC的潜在生物标志物和治疗靶标。