Robo2 Predicts a Better Prognosis and Inhibits Malignant Behavior in Vivo in Pancreatic Ductal Adenocarcinoma
Abstract BackgroundPancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy with an extremely poor prognosis and a high mortality rate. Genome-wide studies have shown that the SLIT/ROBO signaling pathway plays an important role in pancreatic tumor development and progression. However, the effect and mechanism of ROBO2 in the progression of pancreatic cancer remains largely unknown.MethodsIn this study, real-time polymerase chain reaction (RT-PCR) and western blot analyses were adopted to evaluate the expression level of ROBO2 and proteins in pancreatic cell lines. Cell migration and invasion and cell proliferation were conducted in AsPC-1 and MIA PaCa-2 cell lines. RNA sequencing and western blot were undertaken to explore the mechanisms and potential targeted molecules. ROBO2 expression in tumor tissues was evaluated by immunohistochemistry in 95 patients.ResultsROBO2 expression was downregulated in PDAC cell lines and tissue samples. A high level of ROBO2 was associated with good overall survival. Upregulation of ROBO2 inhibited PDAC cell proliferation, migration, and invasion, whereas the opposite results were found in the ROBO2 downregulation group. In addition, xenograft animal models further confirmed the effect of ROBO2 on proliferation. Finally, the RNA sequencing results indicated that ROBO2 facilitates anti-tumorigenicity partly via inhibiting ECM1 in PDAC. ConclusionsOur work suggests that ROBO2 inhibits tumor progression in PDAC and may serve as a predictive biomarker and therapeutic target in PDAC.