| Background: Currently,cancer is one of the leading causes of death from human diseases,and liver cancer has the second highest mortality rate among all cancer.Among them,hepatocellular carcinoma(HCC)is the most common histological type.Sorafenib,the first targeted drug approved for the treatment of hepatocellular carcinoma,is a multi-targeted kinase inhibitor,but the existence of drug resistance has greatly limited its further clinical application.Antisense circular RNA(antisense circ RNA)is a special type of circular RNA that is derived from the antisense complementary strand of parental m RNA,and thus can bind to the parental m RNA and may be involved in regulating the expression of parental m RNA at the transcriptional,splicing,and translation levels.However,the function of antisense circular RNAs in HCC progression and therapeutic resistance is still unclear.Objective: The main objective of this study was to investigate the role of CSF3R-AS in the progression of hepatocellular carcinoma and sorafenib resistance,and to explore new targets for the clinical treatment of hepatocellular carcinoma.Methods: Firstly,circ RNA microarray was used to screen the expression of antisense circ RNAs in hepatocellular carcinoma and paraneoplastic tissues.QRT-PCR,sanger sequencing,Rnase R treatment and agarose gel electrophoresis were used to verify the circular structure of CS3R-AS.The relationship between CSF3R-AS and prognostic and clinicopathological features of hepatocellular carcinoma was further verified using K-M survival curve method,chi-square test,one-way and multi-way COX regression analysis.Subsequently,CSF3R-AS overexpression and knockdown stable cell lines were constructed by lentiviral infection,and the effects of CSF3R-AS on hepatocellular carcinoma proliferation,angiogenesis,apoptosis and metastasis were examined using CCK8,clone formation,Ed U,flow cytometry,trasnwell,tube formation assay,immunohistochemistry,nude mice subcutaneous tumor model,tail vein injection model and small animal live imaging.Mechanically,bioinformatics analysis,RNA pull-down,laser confocal microscope,CHIP-PCR,and Western Blot experiments were performed to confirm that CSF3R-AS promotes hepatocellular carcinoma progression and sorafenib resistance by activating the CSF3R/JAK2/STAT3 positive feedback loop.Results: CSF3R-AS is significantly elevated in hepatocellular carcinoma and correlates with poor prognosis of HCC,and is expected to be a potential prognostic marker.CSF3R-AS promotes the proliferation,angiogenesis and metastasis of HCC.By contrast,CSF3R-AS inhibits the apoptosis of HCC.Mechanistically,CSF3R-AS has a 180-base complementary pairing sequence with its parental m RNA,which can directly bind to its parental m RNA CSF3 R and recruit RNA-binding protein RBMS3 to stabilize its parental m RNA,and finally activate JAK2/STAT3 signaling pathway.Meanwhile,STAT3 can bind to the promoter region of CSF3R-AS and act as a transcription factor,which in turn initiates the transcription of CSF3R-AS.Therefore,the activation of CSF3R-AS/CSF3R/JAK2/ STAT3 positive feedback loop can promote the progression of HCC.Meanwhile,this study found that CSF3R-AS/CSF3R/JAK2/STAT3 positive feedback loop is also activated in hepatocellular carcinoma sorafenib-resistant cells,and blocking this loop is expected to improve the sensitivity of hepatocellular carcinoma to sorafenib.Conclusion: CSF3R-AS/CSF3R/JAK2/STAT3 positive feedback loop was activated in HCC and can promote the progression and sorafenib resistance of HCC.Blocking this loop is expected to provide a new research direction for the treatment and sensitization to sorafenib of hepatocellular carcinoma.Figures: 21,Tbles: 16,Text references: 100,Review reference: 123... |
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