Role Of MiR-223 In The Pathogenesis Of Pancreatic Cancer

Pancreatic cancer is one of the common and malignant tumor in digestive system.In recent years,the prevalence of pancreatic cancer has been increasing all over the world. According to statistics,in the United States, about new 42,470 patients with pancreatic cancer were diagnosed in the year of 2009,of which about 83% of patients died within 1 years, Pancreatic cancer accounts for only 2% -3%of the total number of cancer, but the mortality rate among the cancer death is the 4th leading cause; in China, pancreatic cancer incidence rate in recent 20 years increased by nearly 6 times, the 5th of cancer mortality rates .For its deep location,it is difficult to be discovered at the early stage Traditional treatments, such as chemotherapy,radiotherapy and surgery couldn't control it efficiently. Therefore, the incidence of pancreatic cancer is more and more serious and the mortality rate has been high.Although the biological markers of pancreatic cancer was substantial and extensive research, including genetic markers, serological markers and cytological markers, etc, but because of the specificity and sensitivity of these indicators ,the use of these immune markers to diagnosis still has many defects, we need a better indicator of clinical significance for the diagnosis of pancreatic cancer.A recently identified class of non-coding small RNAs, microRNAs (miRNAs), may provide new insights in pancreatic cancer research. miRNAs , Widely found in eukaryotes ,are small non-coding RNAs of 19–23 nucleotides and constitute an abundant class of gene regulators that negatively regulate gene expression at the post-transcriptional level. A total of 678 human miRNAs have been reported (April 2008 release of miRBase at the Sanger Institute). Most of miRNAs express in different physiological and pathological circumstances. Previous results about miRNAs indicated that miRNA might play an important role in the tumorigenesis and development of cancer and could be as tumor suppressors and oncogenes. miRNA may be used as a new potential diagnostic biomarker for cancer and so on. Present study shows that many genes of pancreatic cancer tissue and cell have been mutated, such as Notch, IGF, K-Ras, MUC, PI3K-AKT, sonic hedgehog and so on. These mutations mainly attributed to three factors important signal transduction pathways: Ras-MAPK signaling pathway, PI3K-AKT-mTOR signaling pathway and Hedgehog signaling pathways. A member of abnormal activation or mutation of Hedgehog signaling pathway can lead to pancreatic cancer. Glil (Glioma-associated Oncogene Homolog l, Glil) was originally discovered in the study of glioma, its encoded protein is one of the most important downstream transcription factors for Glil Hh pathway, but also the end response and the enforcement of function for the Hh signal. The target of SUFU is GLI which located downstream of Smo, tumor suppressor gene SUFU is a major negative regulator factor for Hedgehog signaling pathway in mammalian .Recent studies have found that microRNAs can involve in the activation of Hedghog signaling pathway and lead to carcinoma.According to this study,we detect the expression of miRNA-223 in pancreatic cancer, paracancerous tissues and normal pancreas tissues and evaluate the diagnositic value of miR-223 as a diagnostic marker in pancreatic cance. Detecting the Gli1,SUFU mRNA expression in paracancerous tissues and pancreatic cancer tissue ; discussing the significance of alteration of the two mRNA expressions in the mechanism of pancreatic tumorigenesis and its possible application in cancer therapy.Also,we analyzed whether there is any correlation in the expression of miR-223 and pancreatic cancer-related signaling pathways,providing an important basis to the diagnosis of pancreatic cancer.1. To detect the miRNAs in pancreatic cancer cells and tissues ,which screened in human plasma by microarrayObjective: To detect the expression of miR-223 in 7 pancreatic cancer cell lines and the expression of 7 miRNAs in pancreatic cancer and paracancerous tissues, Screening of high expression of miRNAsMaterials and methods: the samples were collected from pancreatic cancer patients(pancreatic cancer and paracancerous tissues n=10 couple) and normal person(n=3). 7 pancreatic cancer cell lines are saved by the Department of Gastroenterology, Changhai Hospital laboratory .Total RNA was extracted from sample, then it was transcripted into cDNA. Expressions of 7 miRNAs (miR-20a,miR-26a,miR-142-3p,miR-1202,miR-1207-5p,miR-1228,miR-223,)were detected by step-loop real-time PCR ,U6 was used as internal control..Results: Normal pancreatic tissues as controls, in10 pancreatic cancer tissues and paracancerous tissues, only miRNA-223 in pancreatic cancer tissue(3.55±3.73) may be higher than paracancerous tissues(2.67±1.94), and the remaining 6 miRNAs in pancreatic cancer tissues were not higher than paracancerous tissues The expression of miR-223 in BXPC-3(61.07±16.16) was significantly higher than 293 cell lines(P<0.05) .Conclusion: miRNA-223 may be highly expressed in pancreatic cancer, The remaining 6 miRNAs changed little in pancreatic cancer tissues and corresponding adjacent tissues. miR-223 might play an important role in the pathogenesis and development of pancreatic cancer.2.The expression of miR-223 in human pancreatic cancer tissues and paracancerous tissues and the correlation between the expression of miR-223 and clinicopathological parameters in human pancreatic cancer tissues.Objective: To detect the expression of MicroRNA-223 in pancreatic cancer and paracancerous tissues, and its relationship with clinicopathological parameters in pancreatic carcinoma ,whether microRNA-223 can be a potential diagnostic marker for pancreatic cancer .Materials and methods: 50 cases of pancreatic cancer patients were included in this study. Pancreatic cancer and paracancerous tissue were collected from every pancreatic cancer patient after surgery. Three normal pancreas were used as control. Relative quantification (RQ) of miR-223 in tissues were detected by reverse transcriptase PCR and real time PCR. U6 was used as internal control. The relationships between clinicopathological parameters of pancreatic cancer and the RQ of miR-223 were analyzedResults: The RQ of miR-223 in pancreatic cancer tissues 3.47(1.53,6.03)were significantly higher than in paracancerous tissues1.52(0.61,3.25)(P=0.011).The highly expressed miR-223 did not correlate with clinicopathological parameters such as sex, age, tumor maximal diameter and the level of serum CA19-9(P>0.05)Conclusion: miR -223 expression in pancreatic cancer was significantly higher than paracancerous tissues, miR-223 might play an important role in the tumorigenesis and development of pancreatic cancer. It may be used as a new potential diagnostic biomarker for pancreatic cancer.The relationship analysis between the expression of MiR-223 in pancreatic cancer and the biological characteristics of pancreatic cancer showed that the expression of MicroRNA-223 in pancreatic cancer have no correlation with patients age, sex, tumor location, maximum tumor diameter, clinical stage, lymph node metastasis, distant transfer CA19-9 ,indicating that the highly expression of miR-223 in pancreatic cancer may be as an early event in tumorigenesis. Because the serum CA19-9 have correlation with maximum tumor diameter and clinical stage,and the serum CA19-9 is low sensitivity in early pancreatic cancer, the stability of miR-223 in various stages of the tumor indicated that it can be a tumor marker that may have a certain supplementary diagnostic value to serum CA19-9.3. The correlation between the expression of MicroRNA-223 and changes of GLI1, SUFU gene expression in pancreatic cancerObjective :To detect the expression of GLI1, SUFU gene at the mRNA level in pancreatic tissue and paracancerous tissues, and discussing the link between changes of GLI1, SUFU gene expression in pancreatic cancer and the expression of MicroRNA-223 in pancreatic cancerMaterials and methods:: 46 cases of pancreatic cancer patients were included in this study. Pancreatic cancer and paracancerous tissue were collected from every pancreatic cancer patient after surgery. Three normal pancreas were used as control. Relative quantification (RQ) of GLI1, SUFU mRNA in tissues were detected by reverse transcriptase PCR and real time PCR. GAPDH was used as internal control. We detected the expression of GLI1, SUFU gene at the mRNA level in pancreatic tissues and paracancerous tissues and the relationships between the expression of MicroRNA-223 in pancreatic cancer and the expression of GLI1, SUFU mRNA in pancreatic cancer were analyzed .Results: Compared with normal pancreatic tissues, the expression of GLI1mRNA in pancreatic cancer tissues 4.81(1.21,10.10)was significantly higher than paracancerous tissues 1.99(0.68,5.56)(P=0.042), the expression of SUFU mRNA in pancreatic cancer tissues 1.23(0.80,2.29)was similar with paracancerous tissues1.72(1.11,2.48) (P=0.4), the expression of GLI1mRNA in paracancerous tissues had correlation with the expression of miR-223 in paracancerous tissues (r=0.432,p=0.005) . The expression of GLI1, SUFUmRNA in the pancreatic cancer and the expression of miR-223 in pancreatic cancer were no significant correlation(P>0.05).Conclusion: The expression of GLI1mRNA in pancreatic cancer tissues was significantly higher than paracancerous tissues , the expression of GLI1mRNA in paracancerous tissues had correlation with the expression of miR-223 in paracancerous tissues . It showed that GLI1 gene and miR-223 may play a coordinating role in the pathogenesis of pancreatic cancer.