A Study Of Plasma MiRNA Associated With Pancreatic Cancer Diagnosis

Background:Pancreatic cancer is a kind of high malignant tumor, it is one of the worst prognosis of tumor in the digestive system tumors. Pancreatic cancer in early ages usually has no obvious clinical symptoms and signs, surgery is the main treatment for pancreatic cancer. Nearly95%of the patients with pancreatic cancer at an advanced stage when diagnosed, the surgical resection rate in10%～20%, the5-year survival rate<20%. Therefore early diagnosis is expected to improve the cure rate of pancreatic cancer.MiRNA is a family of highly conserved, length in17～25nucleotides non-coding small RNA, It can regulate the expression of signal molecules, it has a high specificity in tissue and tumor. Micrornas are not encoded protein, is highly conservative, scheduling, and tissue specificity.Recent studies have pointed out that a large number of micrornas play an important role in regulating various physiological processes Such as cell proliferation, apoptosis, individual development, differentiation and inflammatory reaction, stress reaction, etc. Present study suggests that many differentially expressed micrornas were also associated with the occurrence of tumor development.Objective:The study was performed to identify6miRNAs expressed in plasma of pancreatic cancer (PC) and analyzed them as a diagnostic index value of pancreatic cancer.Method:Select30cases from March2012to June2013in the Chinese academy of medical sciences tumor hospital who are initial diagnosed of pancreatic cancer and26cases of normal volunteers. Using the method of real-time quantitative PCR to detect6(miR-21, miR-210, miR-155, miR-20a. A, miR-25, miR-196a) kinds of micrornas in56cases. The correlation of the expression of microRNAs with the clinical characteristics and the diagnostic value were analyzed. The joint value of miRNA and CA199as diagnostic marker of pancreatic cancer were analyzed Using Logist regression method.Result:All six miRNAs were significantly upregulated in the PCa group compared with the normal group the difference was significant (p<0.05).The expression of six kinds of micrornas have no obvious correlation with the clinical characteristics of patients with pancreatic cancer.Used the ROC curve to evaluate the diagnostic value of pancreatic cancer,miR-21has the highest diagnostic value when it was used as diagnostic marker alone (AUC-ROC0.893).The combination of miR-155and miR-25was more effective to distinguish PCa from normal than to be used alone.There was a high improvement in sensitivity and accuracy for diagnostic value when miR-210and miR-25combind with CA199respectively.Conclusion:Plasma miR-21, miR-155, miR-25, miR-210have diagnostic value for pancreatic cancer,which deserves further study.