RNA-Seq profiling of circular RNAs in human colorectal cancer 5-fluorouracil resistance and potential biomarkers

BACKGROUND Colorectal cancer(CRC)is a commonly diagnosed cancer of the digestive system worldwide.Although chemotherapeutic agents and targeted therapeutic drugs are currently available for CRC treatment,drug resistance is a problem that cannot be ignored and needs to be solved.AIM To explore the relationship between circular RNA(circRNA)and CRC drug resistance.circRNA plays a key role in the occurrence and development of cancers,but its function in the process of drug resistance has not been widely revealed.METHODS To explore the role of circRNA in 5-fluorouracil(5-Fu)resistance,we performed the circRNA expression profile in two CRC cell lines and their homologous 5-Fu resistant cells by high-throughput sequencing.RESULTS We validated the differentially expressed circRNAs in other two paired CRC cells,confirmed that circ_0002813 and circ_0000236 could have a potential competitive endogenous RNA mechanism and be involved in the formation of 5-Fu resistance.And we combined the sequencing results of mRNA to construct the regulatory network of circRNA-miRNA-mRNA.CONCLUSION Our study revealed that circ_0002813 and circ_0000236 may as the biomarkers to predict the occurrence of 5-Fu resistance in CRC.

Macrophages play a role in inflammatory transformation of colorectal cancer

Colorectal cancer(CRC)is one of the most common and fatal cancers worldwide,and it is also a typical inflammatory cancer.The function of macrophages is very important in the tissue immune microenvironment during inflammatory and carcinogenic transformation.Here,we evaluated the function and mechanism of macrophages in intestinal physiology and in different pathological stages.Furthermore,the role of macrophages in the immune microenvironment of CRC and the influence of the intestinal population and hypoxic environment on macrophage function are summarized.In addition,in the era of tumor immunotherapy,CRC currently has a limited response rate to immune checkpoint inhibitors,and we summarize potential therapeutic strategies for targeting tumorassociated macrophages.

Antifibrotic Effect of Total Flavonoids of Astmgali Radix on Dimethylnitrosamine-lnduced Liver Cirrhosis in Rats

Objective：To study the effect of total flavonoids of Astmgali Radix（TFA）on liver cirrhosis induced with dimethylnitrosamine（DMN）in rats,and the effect on peroxisome proliferator-activated receptorγ（PPARγ）,uncoupling protein 2（UCP2）and farnesoid X receptor（FXR）.Methods：Fifty-three Sprague-Dawley rats were randomly divided into a control group（10 rats）and a DMN group（43 rats）.Rats in the DMN group were given DMN for 4 weeks and divided randomly into a model group（14 rats）,a low-dosage TFA group（14 rats）and a high-dosage TFA group（15 rats）in the 3rd week.Rats were given TFA for 4 weeks at the dosage of 15 and 30 mg/kg in the low-and high-TFA groups,respectively.At the end of the experiment blood and liver samples were collected.Serum liver function and liver tissue hydroxyproline content were determined.hematoxylin-eosin（HE）,Sirus red and immunohistochemical stainings of collagenⅠ,smooth muscle actin（α-SMA）was conducted in paraffinembedded liver tissue slices.Real time polymerase chain reaction（PCR）was adopted to determine PPARγ,UCP2 and FXR m RNA levels.Western blot was adopted to determine protein levels of collagenⅠ,α-SMA,PPARγ,UCP2 and FXR.Results：Compared with the model group,TFA increased the ratio of liver/body weight（low-TFA group P〈0.05,high-TFA group P〈0.01）,improved liver biochemical indices（P〈0.01 for ALT,AST,GGT in both groups,P〈0.05 for albumin and TBil in the high-TFA group）and reduced liver tissue hydroxproline content（P〈0.01 in both groups）in treatment groups significantly.HE staining showed that TFA alleviated liver pathological changes markedly and Sirus red staining showed that TFA reduced collagen deposition,alleviated formation and extent of liver pseudolobule.CollagenⅠandα-SMA immunohistochemical staining showed that staining area and extent markedly decreased in TFA groups compared with the model group.TFA could increase PPARγ,it regulated target UCP2,and FXR levels significantly compared with the model group（in the low-TFA group all P〈0.05,in the high group all P〈0.01）.Conclusions：TFA could improve liver function,alleviate liver pathological changes,and reduce collagen deposition and formation of liver pseudolobule in rats with liver cirrhosis.The antifibrotic effect of TFA was through regulating PPARγsignal pathway and the interaction with FXR.