| Background: Pancreatic cancer(PC)is a malignant tumor of digestive tract,with difficulty in early detection,high malignant degree and poor prognosis.Currently,it is one of the deadliest malignancies in the world.The incidence and mortality of PC are increasing in recent years.Although surgical approach is the most effective treatment for PC,up to 85% of patients with PC cannot be removed surgically due to tumor metastasis every year.Therefore,it is of great significance to find effective biomarkers and potential therapeutic targets for PC.Long non-coding RNAs(lnc RNAs)can be involved in tumor progression in diverse pathways and served as biomarkers for diagnosis.However,the mechanism of lnc RNAs participating in PC have not been fully elucidated.Therefore,it would be crucial for indicating the underlying mechanisms of lnc RNAs in PC progression.Objective: The purpose of the study is to detect the relationship between abnormal expression of lnc RNA and the clinicopathologic characteristic and prognosis of PC,to explore the lnc RNA effect on the migration,invasion and proliferation in PC cells,and to probe the possible molecular mechanisms.Methods: The expression difference sequenced lnc RNA was analyzed by high-throughput gene chip in 3 PC species and paired normal tissues,and the low expression of lnc RNA termed as lnc-CEPAS was screened;The expression level of lnc-CEPAS was detected in 50 PC tissues and paired normal tissues,analyzing the relationship between its expression and clinicopathology;Bx PC-3 cells were supplied as templates to determine the downstream binding protein by Ch IRP-MS,RNA-Protein Pull-Down and RIP experiments.Its expression at protein and m RNA level was detected by immunohistochemistry(IHC)and RT-q PCR,respectively.Transwell and CCK8 assay were used to detect cell migration,invasion and proliferation regulated by lnc-CEPAS and its binding protein in PC cells.The effect of lnc-CEPAS on the volume and quatity of subcutaneous xenograft tumors were detected by subcutaneous xenograft in nude mice experiment.The effect of lnc-CEPAS and its binding protein on PC cell migration and invasion was inversely verified by rescue experiment.Results: Lnc-CEPAS was low expressed in PC tissues and it was correlated with TNM stage and Overall Survival in PC patients.The experiments results of Ch IRP-MS、RNA-Protein Pull-Down and RIP verified that lnc-CEPAS can directly bind hn RNPK;Lnc-CEPAS overexpression in Bx PC-3 and PANC-1cells showed the m RNA level of hn RNPK remained unchaged,whereas the protein level of hn RNPK downregulated.Overexpression of lnc-CEPAS or knockdown of hn RNPK in Bx PC-3and PANC-1cells inhibited cell migration,invasion and proliferation.Overexpression of lnc-CEPAS in Bx PC-3 cell,the volume and weight of subcutaneous xenograft tumors substantially reduced,meanwhile IHC revealed that the protein content of hn RNPK decreased.Cell migration and invasion were partially restored after lnc-CEPAS and hn RNPK were both overexpressed in Bx PC-3 and PANC-1 cells.Conclusions: The down-regulation of lnc-CEPAS expression in PC tissues can be potentially served as a predictive biomarker.Furthermore,lnc-CEPAS negatively regulates hn RNPK protein expression by directly binding it and acts as a tumor suppressor in PC by inhibiting cell migration,invasion and proliferation. |
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