Significance of LNCRNA's in diagnosis and prognosis of pancreatic cancer

Pancreatic cancer is the fourth most common cancer related to mortality. Serum analysis of patients with pancreatic cancer have revealed several detectable antigens. Best clinically usefull serum antigene in those patients is mucin-associated carbohydrate antigen, CA 19-9. Various molecular studies including small noncoding RNA such as siRNA, miRNA ve lncRNA (long noncoding RNA) have been investigated as a new biomarker of pancreatic cancer. LncRNA are RNAs transcribed from the intergenic and intronic regions of the human genome and are known to be effective in the carcinogenesis process. The aim of this study was to investigate the roles of lncRNAs in pancreatic cancer. The second aim was to demonstrate the relation between lncRNA levels and clinical, demographic and labaratory findings of pancreatic cancer patients and to evaluate the potencial of lncRNA's as a new circulating markır of pancreatic cancer. In vitro studies were carried out in two different pancreatic cell lines. One of them was pancreatic ductal adenocarcinoma cell line (PANC-1) and other was normal pancreatic cell line (HPDE). Cell lines were grown in culture conditions and used in the study. Cell proliferation index and cytotoxicity studies were performed by using WST-1 assay. Beside invitro studies, plasma of pancreatic cancer patients were included to study. Fourty patients, 18 years old or older diagnosed with pancreatic cancer and 10 healthy control were evaluated. Patients were informed about the study and informed consents were optained. The literature related to the lncRNA and oncogenesis were reviewed. The lncRNA's associated with pancreatic cancer were selected. The expression levels of lncRNA's were determined by using template cDNA samples and qPCR Array study "All-in-OneTM qPCR Mix" (Genecopoeia). Primers / probes specifically designed for our target lncRNA's (ANRIL, H19, HOTAIR, MALAT1, PCA3, PTCSC3) and housekeeping genes (ACTB, B2M, GAPDH) were used for the study. The initial step in our study was to measure the expression level of lncRNA by qPCR in serum of pancreatic cancer patients. Expression levels of same lncRNA's in pancreatic cell lines in vitro were investigated to proof the efficiacy of lncRNA measurements as diagnostic and prognostic markers in pancreatic cancer. In PANC1 pancreatic cancer cell line the expression levels of ANRIL, H19, HOTAIR, MALAT1, PCA3 and PTCSC3 lncRNA were respectivelly 0.58, 4.60, 4.19, 0.66, 1.25 and 0.38 times higher compared to HPDE cell line. When patients plasma lncRNA levels were compared to healthy controls the lncRNA changes were 5.85, 3.91, 4.22, 1.70, 1.81 and 3,93 times lower respectivelly. Plasma lncRNA levels in pancreatic cancer patients were affected by diabetes, alcohol and smoking habbits. Advanced disease stage increased the changes in selected plasma lncRNA expressions. In conclusion, in vitro analysis of lncRNA expresssion showed that H19 and HOTAIR lncRNA expression increase in PANC1 cell line. However the plasma expression levels of ANRIL, H19, HOTAIR, and PTCSC3 lncRNA's in pancreatic cancer patients were lower. Those changes were also affected by diabetes, alcohol and smoking status and the early diagnosis of pancreatic cancer by plasma lncRNA analysis appears to be not effective.