Biological Mechanism Of CircIGF1R In Lung Adenocarcinoma

Objective : As the most common malignant tumor with the highest mortality rate in China and even in the world,lung cancer is a serious threat to human health.Among them,the incidence of lung adenocarcinoma is getting higher and higher,which has caused disastrous social impact.Therefore,the main direction of prevention and treatment of lung adenocarcinoma is to actively and deeply explore the pathogenesis of lung adenocarcinoma and find new and effective early diagnosis methods and new therapeutic targets.Circ RNA(circ RNA)is a kind of non-coding RNA with closed loop structure produced by special splicing mechanism.It is a star molecule in the field of life science research at present.Recent studies have found that circ RNA can play a role in the occurrence and development of various tumors,including lung cancer,through competitive inhibition of mi RNA and other biological mechanisms.In the previous microarray analysis,we found that the expression level of circ IGF1 R in lung adenocarcinoma tissues was significantly lower than that in adjacent normal tissues,and bioinformatics analysis found that circ IGF1 R had a complementary pairing sequence with mi R-1270,suggesting that circ IGF1 R may play a key role in lung adenocarcinoma.However,no relevant reports have been reported so far.This study aims to explore the mechanism of action of circ IGF1 R in lung adenocarcinoma,and to provide a new idea for the diagnosis and treatment of lung adenocarcinoma.Method:(1)The expression level of circ IGF1 R in lung adenocarcinoma was obtained by bioinformatics analysis of gene chip GSE104854 and its circular structure was verified.RNA-seq sequencing technology was used to sequence the lung adenocarcinoma cell lines A549 and PC9 after circ IGF1 R overexpression,as well as the control cell lines.The possible downstream mi RNA,m RNA and signaling pathways of circ IGF1 R were analyzed in combination with the biological information database.(2)Si-circ IGF1 R was transfected into lung adenocarcinoma cell line A549 and PC9 to reduce the content of circ IGF1 R,and si-NC was used as the control group.The circ IGF1 R overexpressed plasmid was constructed and transfected into lung adenocarcinoma cell line A549 and PC9 to increase the content of circ IGF1 R,and OV-NC was used as the control group.The experimental groups were divided into si-circ IGF1 R group,si-NC group,OV-circ IGF1 R group and OV-NC group.The effect of circ IGF1 R on the function of lung adenocarcinoma cells was verified by scratch test and Transwell invasion test.(3)The quantitative real time polymerase chain reaction(quantitative real time polymerase chain reaction)was used after the intervention.QRT-PCR)and Western blot assay were used to detect the downstream mi RNA,m RNA and related signaling pathway related proteins of circ IGF1 R.Result:(1)The expression of circ IGF1 R was significantly lower in lung adenocarcinoma tissues(P < 0.01),and bioinformatics analysis preliminarily identified the potential network of circ IGF1R-mi R-1270-vangl2,and also involved in the downstream Wnt signaling pathway.(2)The results of scratch healing experiment and Transwell experiment showed that the number of metastatic and invaded cells was significantly decreased after circ IGF1 R overexpression(P < 0.01),and the number of metastatic and invaded cells was significantly increased after circ IGF1 R knockdown(P < 0.05).(3)Compared with the control group,the expression level of mi R-1270 in si-circ IGF1 R group was significantly up-regulated(P<0.01),and the expression level of VANGL2 was significantly down-regulated(P<0.001).In OV-circ IGF1 R group,the expression level of mi R-1270 was significantly down-regulated compared with the control group(P<0.05),and the expression level of Vangl2 was significantly up-regulated compared with the control group(P<0.001).According to this hypothesis,it can be stored in the circ IGF1R-mi R-1270-vangl2 pathway.Western Blot experiments confirmed the above hypothesis.Conclusion:(1)Low expression of circ IGF1 R in lung adenocarcinoma.(2)Overexpression of circ IGF1 R inhibits migration and invasion of human lung adenocarcinoma cell lines.Knocking down circ IGF1 R can promote migration and invasion of human lung adenocarcinoma cell lines.Circ IGF1 R was negatively correlated with invasion and migration of human lung adenocarcinoma cells.(3)Circ IGF1 R can affect the Wnt signaling pathway through the circ IGF1 R /mi R-1270/ Vangl2 axis,and thus inhibit the progression of lung adenocarcinoma.