Identification Of Gastric Cancer Related Hsa＿circ＿0000419 And Its Clinical Significance

ObjectiveGastric cancer(GC),an aggressive malignant tumor characterized by significant clinical heterogeneity,is the third common cause of cancer related mortality worldwide and pose a serious threat to human health.A lot of GC patients are diagnosed at advanced stage with tumor invasion or metastasis due to GC often lacks typical symptoms,especially in its early stage.With timely treatment,the 5-year overall survival rate of early GC patients can reach over 90%.While once tumor progress to an advanced stage,its mortality rate increases dramatically.Therefore,early diagnosis is not only crucial to improve the prognosis of GC patients but also important to improve the prevention and treatment level of GC.Circular RNAs(circRNAs)are a class of RNAs produced by precursor RNA molecules through alternative splicing and covalently connecting the 5’ end to the 3’ end.CircRNAs participate in the proliferation,differentiation,invasion and metastasis of tumor cells at multiple levels.However,the relationship between circRNAs and GC remains unclear.Therefore,the screening and identification of gastric cancer-related circRNAs provide new perspectives for the study of GC prevention strategies.This project is based on a preliminary study.The aim is to select and identify gastric cancer-related circRNA molecule hsa＿circ＿0000419,then clarify the feasibility and clinical application value of it in GC diagnosis and patient prognosis evaluation.Methods1.Quantitative reverse transcription-polymerase chain reaction(qRT-PCR)was performed to detect hsa＿circ＿0000419 level in normal gastric mucosal epithelial cell lines,4 different gastric cancer cell lines,GC tissues and adjacent paracarcinoma tissues;Analyze the changes of hsa＿circ＿0000419 expression level in different pathological stages of gastric mucosa.2.To analyze the relationship between hsa＿circ＿0000419 levels and the clinicopathological characteristics as well as the prognosis of patients with GC.3.To analyze plasma hsa＿circ＿0000419 level in healthy controls and GC patients.Receiver operating characteristic(ROC)curve was constructed to clarify the diagnostic value of plasma hsa＿circ＿0000419;relationship between plasma hsa＿circ＿0000419 level and clinicopathological parameters of patients with GC were analyzed.4.Plasma hsa＿circ＿0000419 stability identification and source investigation.5.Using bioinformatics method to analyze the potential biological functions of hsa＿circ＿0000419.Results1.Hsa＿circ＿0000419 was only significantly downregulated in GC cell lines and tissues,but no significant changes in gastritis and dysplasia.2.The level of hsa＿circ＿0000419 in GC tissue is closely related to tumor differentiation grade(P = 0.007)and Borrmann type(P = 0.018);GC patients with lower hsa＿circ＿0000419 level have worse prognosis.3.Plasma hsa＿circ＿0000419 level of GC patients also significantly decreased.When the cutoff value was 4.90,the sensitivity and specificity of plasma hsa＿circ＿0000419 in GC screening are68.2% and 88.4%,respectively.4.Plasma hsa＿circ＿0000419 is closely correlated with tumor stage(P = 0.01),lymphatic(P =0.046),distal metastasis(P = 0.013),vascular(P = 0.018)and perineural invasion(P = 0.002),as well as tissue CA19-9 levels(P = 0.048).5.Plasma hsa＿circ＿0000419 is stable enough to meet the needs of clinical analysis.Plasma exosomes tests showed that plasma hsa＿circ＿0000419 was mainly derived from exosomes.6.Bioinformatics technology reveals that hsa＿circ＿0000419 may participate in the tumorigenesis and evolution of GC through function as miRNA(microRNA,miRNA)sponge.ConclusionHsa＿circ＿0000419 can not only be used as a potential biological marker for GC screening,but also an important indicator for the prognostic estimation of GC patients.Plasma hsa＿circ＿0000419mainly originate from the release of exosomes,and the encapsulation in exosomes enables it to maintain good stability.Hsa＿circ＿0000419 may participate in the tumorigenesis and evolution of GC through function as miRNA sponge.