Studies On Differentially Expressed Circular RNAs In Human Colorectal Cancer

BACKGROUND:Circular RNAs are emerging as promising biomarkers of diagnosis and prognosis and therapeutic targets in cancer.The exploration of the relationship between circular RNAs and colorectal cancer has seen much progress.Screening is the cornerstone for early detection and prevention of CRC.The existing screening modalities are still not universally desirable.Furthermore,despite advances in therapeutic protocols and modalities and careful patient selection,survival remains less than satisfactory.OBJECTIVE:To identify new circular RNAs that were dysregulated in colorectal cancer tissue samples.PATIENTS AND METHODS:Paired colorectal cancer tissues and matched adjacent non-cancerous tissues were collected from patients undergoing surgical resection of colorectal cancer without any prior therapy at the Department of Surgical Oncology of the First Affiliated Hospital of Kunming Medical University.Experiments were carried out in the Institute of Medical Biology Chinese Academy of Medical Sciences.6 paired samples were selected from the collection for circular RNA profiling based on the purity and concentration of total RNA samples.Circular RNAs were extracted by micro-array analysis.4 circRNAs were found to be consistently significantly dysregulated circular RNAs.Among them 3 circRNAs were validated by qRT-PCR.circRNA/microRNA interaction was predicted with Arraystar’s home-made miRNA target prediction software based on TargetScan&miRandaRESULTS:The mean age of patients was 66.83 years with equal number of males and females.A total of 156 significantly differentially expressed circRNAs were identified from all samples（fold change>2;p<0.05）.Among them 78 were up-regulated and 78 were down-regulated circRNAs.Among them 4 circRNAs were consistently significantly dysregulated.By using rt-PCR the expression of hsa_circ₀001955,hsa_circ₀001806 and hsa_circ₀043278 were found to be significantly different in CRC tissues.CONCLUSION:We found that hsa_circ 0001955、hsa_circ 0001806 and hsa_circ₀043278 were significantly dysregulated in CRC tissues as compared to adjacent non-cancerous tissues and they are expected to be a candidate for early screening for CRC.