The role of AFAP1-AS1 in mitotic catastrophe and metastasis of triple-negative breast cancer cells by activating the PLK1 signaling pathway

Triple-negative breast cancer(TNBC)is characterized by fast growth,high metastasis,high invasion,and a lack of therapeutic targets.Mitosis and metastasis of TNBC cells are two important biological behaviors in TNBC malignant progression.It is well known that the long noncoding RNA AFAP1-AS1 plays a crucial role in various tumors,but whether AFAP1-AS1 is involved in the mitosis of TNBC cells remains unknown.In this study,we investigated the functional mechanism of AFAP1-AS1 in targeting Polo-like Kinase 1(PLK1)activation and participating in mitosis of TNBC cells.We detected the expression of AFAP1-AS1 in the TNBC patient cohort and primary cells by in situ hybridization(ISH),northern blot,fluorescent in situ hybridization(FISH)and cell nucleus/cytoplasm RNA fraction isolation.High AFAP1-AS1 expression was negatively correlated with overall survival(OS),disease-free survival(DFS),metastasis-free survival(MFS)and recurrence-free survival(RFS)in TNBC patients.We explored the function of AFAP1-AS1 by transwell,apoptosis,immunofluorescence(IF)and patient-derived xenograft(PDX)models in vitro and in vivo.We found that AFAP1-AS1 promoted TNBC primary cell survival by inhibiting mitotic catastrophe and increased TNBC primary cell growth,migration and invasion.Mechanistically,AFAP1-AS1 activated phosphorylation of the mitosis-associated kinase PLK1 protein.Elevated levels of AFAP1-AS1 in TNBC primary cells increased PLK1 pathway downstream gene expression,such as CDC25C,CDK1,BUB1 and TTK.More importantly,AFAP1-AS1 increased lung metastases in a mouse metastasis model.Taken together,AFAP1-AS1 functions as an oncogene that activates the PLK1 signaling pathway.AFAP1-AS1 could be used as a potential prognostic marker and therapeutic target for TNBC.

MCDB: A comprehensive curated mitotic catastrophe database for retrieval, protein sequence alignment, and target prediction

Mitotic catastrophe(MC)is a form of programmed cell death induced by mitotic process disorders,which is very important in tumor prevention,development,and drug resistance.Because rapidly increased data for MC is vigorously promoting the tumor-related biomedical and clinical study,it is urgent for us to develop a professional and comprehensive database to curate MC-related data.Mitotic Catastrophe Database(MCDB)consists of 1214 genes/proteins and 5014 compounds collected and organized from more than 8000 research articles.Also,MCDB defines the confidence level,classification criteria,and uniform naming rules for MC-related data,which greatly improves data reliability and retrieval convenience.Moreover,MCDB develops protein sequence alignment and target prediction functions.The former can be used to predict new potential MC-related genes and proteins,and the latter can facilitate the identification of potential target proteins of unknown MC-related compounds.In short,MCDB is such a proprietary,standard,and comprehensive database for MC-relate data that will facilitate the exploration of MC from chemists to biologists in the fields of medicinal chemistry,molecular biology,bioinformatics,oncology and so on.The MCDB is distributed on http://www.combio-lezhang.online/MCDB/indexhtml/.

Pharmacological evaluation and mechanistic study of compound Xishu Granule in hepatocellular carcinoma

Objective:In this study,we used HepG2 human hepatocellular carcinoma cells to study the effects of Compound Xishu Granule(CXG)on cell proliferation,apoptosis,and the cell cycle in vitro.We also used a xenograft tumor model to study the anti-tumor effects of CXG and related mechanisms in vivo.Methods:The effect of CXG on cell viability was measured using Cell Counting Kit-8 and a colony formation assay.The effect of CXG on apoptosis and the cell cycle was analyzed using flow cytometry.The in vivo anti-tumor effect of CXG was assessed by measuring the volume change in xenograft tumors after drug administration.The CXG anti-tumor mechanism was studied using western blotting assay to detect cell cycle and apoptotic associated proteins.Results:CXG suppressed HepG2 cell proliferation in a time-and dose-dependent manner in vitro.Colony formation experiments showed that CXG administration for 24 h significantly reduced HepG2 cell formations(P<.01).Flow cytometric analysis showed that CXG treatment for 48 h promoted apoptosis and blocked HepG2 cells in the G2/M phase.Western blotting results showed that Bax was significantly upregulated and Bcl-2 was down-regulated in graft tumor tissues and HepG2 cells after CXG administration,which increased the Bax/Bcl-2 ratio.PLK1,CDC25 C,CDK1,and Cyclin B1 expression were upregulated.CXG had a good inhibitory effect on graft tumor growth in vivo.Conclusion:CXG has good anti-tumor effects in vitro and in vivo.In vitro,CXG promoted HepG2 cell apoptosis and induced G2/M phase arrest.In vivo,CXG significantly inhibited graft tumor growth.The CXG mechanism in treating hepatocellular carcinoma may be that CXG can induce abnormal apoptotic and cell cycle associated protein expression,leading to mitotic catastrophe and apoptosis.