Low Expression Of Hsa_circ₀000825 In Colorectal Cancer And Its Clinical Significances

BACKGROUND & PURPOSE: Presently,colorectal cancer?CRC?in the world is the third incidence of malignant tumors,and the mortality rate is fourth.It can improve the survival rate of patients and reduce tum or related mortality by Early diagnosis of tumor and precise prediction of high-risk patients with CRC recurrence,which can guide individualized treatment for tumor patients.Circular RNA?circ RNA?is widely distributed in the cells,and also circ RNAs can be transferred to human exosomes,its Distribution has tissue and disease specificity.Circular RNA is enriched in tissues and exosomes.Circ RNA who belongs to competing endogenous RNA?ceRNA?,also can participates in the regulation of gene expression through a variety of other mechanisms,and regulates a variety of important biological functions such as cell proliferation,apoptosis,development,and carcinogenesis.Because of circ RNA is a closed loop structure which lacking the 3' poly?A?tail and 5' end cap,so it is not easy to be degradated by exonucleases,extremely stable in the organization and exosomes.In summary,circ RNA can serves as potential biomarkers for tumor diagno sis and predicting prognosis.At present,circ RNA has been studied in many kinds of tumors,but current research in colorectal cancer is less,the sample size is small.The purpose of this study is to screen and validate differential expression of circRNA in colorectal cancer and paracancerous tissue by real-time quantitative PCR,and then analyse the the correlation between circRNA and clinical characters.METHODS: 70 colorectal cancer specific circRNAs from circRNA database,were detected by using the Quantitative Real-time polymerase chain reaction?qRT-PCR?microarray in 10 colorectal cancer tissues and the matched adjacent tissues.CircRNA microarray was performed to analyze the expression profile variation of circRNA between 10 cases of CRC tissues and 10 cases matched adjacent tissues.And then expand the sample size,The microarray results were further verified by 30 pairs of colorectal cancer and adjacent tissues.Finally,clinical data collected by a retrospective chart review.Circ RNAs in patients with CRC were analyzed according to clinic pathologic features and patient outcomes.RESULTS:1.In the screening and detection of 10 patients,there were 3 significant differentially expressed circ RNA,which were as follows: hsa_circ₀000825,hsa_circ₀005598 and hsa_circ₀008114.2.Expand the sample size to 30 patients,the circRNA of the above three differential expressions were verified.The results showed that the expression of hsa_circ₀000825 in cancer tissues is significantly lower than that in Paracancerous tissues.The result is consistent with the result of microarray.But the expression of hsa_circ₀005598 and hsa_circ₀008114 in cancer tissues are significantly higher than that in Paracancerous tissues,which are inconsistent with the microarray result,which need to be further verify by expanded the sample.3.The ? Ct value of hsa_circ₀000825 was negatively correlated with the disease-free survival?DFS?of the patients?R=-0.313,P=0.063?.There was no significant difference between the ? Ct value of hsa_circ₀000825 and the DFS of the patients.There was no significant correlation between the ? Ct value and other clinical data.4.Univariate analysis showed that preoperative distant metastasis?P=0.016?,preoperative lymph node metastasis?P < 0.001?and TNM stage?P < 0.001?are correlated with DFS.Preoperative lymph node status is an independent risk factor for DFS.Kaplan-Meier is used to analyze the survival curve of patients with preoperative lymph node metastasis or lymph node no metastasis?P=0.022?,which indicated that the DFS time of patients with preoperative lymph node metastasis is shorter than that of patients with preoperative lymph node no metastasis.CONCLUSION: We found that there are three circ RNA differentially expressed between cancer tissues and adjacent tissues.The expression of hsa_circ₀000825 in cancer tissues is significantly lower than that in adjacent tissues.The expressions of hsa_circ₀005598 and hsa_circ₀008114in cancer tissues are significantly higher than that in adjacent tissues.The patients with low expression of hsa_circ₀000825 in cancer tissues may have shorter DFS,worse prognosis.TNM stage,Preoperative distant metastasis orlymph node metastasis,and surgical procedure are associated with DFS.Preoperative lymph node metastasis is an independent prognostic risk factor.The DFS of patients with lymph node metastasis before operation is shorter.This study provides a theoretical basis for the prevention and treatment of colorectal cancer by screening and validating the circular RNA associated with colorectal cancer and provides a direction for further research.