Objective To explore the related functional mechanism of Xihuang pill containing serum inter-vention in breast cancer cells based on microRNA(miR)21-5p targeting FAM13A gene.Methods Bioinfor-matics websites was used to predict potential miRNAs of FAM13A gene,double luciferase reporter experi-ments were conducted to verify the binding site relationship between FAM13A and predicted miRNAs.The Xihuang pill containing serum was prepared,and human breast cancer MDA-MB-231 cells were cultured.The proliferation of MDA-MB-231 cells was interfered by the Xihuang pill containing serum with different dilution ratios by CCK-8 test,and the best dilution ratio concentration of Xihuang pill containing serum to inhibit the proliferation of breast cancer cells was selected.Real time fluorescence quantitative PCR(RT-qPCR)was ap-plied to detect the relative expression levels of FAM13A mRNA,as well as the relative expression levels of miR21-5p,in MDA-MB-231 cells after intervention with Xihuang pill containing serum.Cell proliferation(Edu)assay and cell apoptosis detection(TUNEL)assay were used to detect the effects of Xihuang pill con-taining serum intervention on cell proliferation and apoptosis function in MDA-MB-231 cells.The siRNA lentiviral transfection on MDA-MB-231 cells was performed to knock down the FAM13A gene,and Edu assay and TUNEL assay were used to detect changes in proliferation and apoptosis ability of MDA-MB-231 cells af-ter lentiviral transfection.The expression level of miR21-5p in MDA-MB-231 cells after FAM13A gene knock-out was detected by RT-qPCR technology.Results Target Scan online website predicted the potential miR-21-5p binding sequence in the 3'UTR of FAM13A mRNA,and dual luciferase reporter assay confirmed the in-teraction between miR-21-5p and FAM13A.After intervention of MDA-MB-231 cells with Xihuang pill drug containing serum,RT-qPCR results showed that compared with the control group(NC group),the Xihuang pill drug containing serum group(XHW group)downregulated the expression levels of FAM13A mRNA(P＜0.05),and upregulated the expression level of miR21-5p(P＜0.05).Compared with the NC group,the XWH group showed reduced cell proliferation ability and promoted cell apoptosis.(P＜0.05).After silencing the FAM13A gene in MDA-MB-231 cells,compared with the control group(shCtrl group),the shFAM13A group showed a significant decrease in cell proliferation ability and promoted cell apoptosis.The RT-qPCR re-sults showed that compared with the shCtrl group,the expression level of miR21-5p was significantly upregu-lated in the shFAM13A group(P＜0.05).Conclusion Xihuang pill could participate in the anti-tumor treat-ment of breast cancer by regulating miR21-5p to affect the expression level of FAM13A gene.

Respiratory viral infections are an important public health problem worldwide, with complex mechanisms of infection, and the key to infection lies in the specific binding between respiratory viruses and receptors. This article provides an overview of the progress in the study of receptors for respiratory viruses, such as coronavirus and influenza virus (IV), with a focus on the binding sites of receptors such as angiotensin-converting enzyme 2 (ACE2) and sialic acid (SA) to respiratory viruses and the role of receptor diversity in respiratory viral infections. An in-depth study of the binding sites between viruses and receptors will help to understand the molecular mechanism of respiratory viral infections and provide a theoretical basis for disease prevention and control and the development of new therapeutic targets.

Respiratory viral infections are an important public health problem worldwide, with complex mechanisms of infection, and the key to infection lies in the specific binding between respiratory viruses and receptors. This article provides an overview of the progress in the study of receptors for respiratory viruses, such as coronavirus and influenza virus (IV), with a focus on the binding sites of receptors such as angiotensin-converting enzyme 2 (ACE2) and sialic acid (SA) to respiratory viruses and the role of receptor diversity in respiratory viral infections. An in-depth study of the binding sites between viruses and receptors will help to understand the molecular mechanism of respiratory viral infections and provide a theoretical basis for disease prevention and control and the development of new therapeutic targets.