| The latest data show that breast cancer has become the malignant tumor with the highest morbidity and mortality among women worldwide.In China,the incidence of breast cancer is also increasing year by year,seriously endangering the lives and health of the people.At present,the clinical treatment of breast cancer is still based on surgical treatment,combined with chemotherapy,radiotherapy,endocrine therapy,targeted therapy,and immunotherapy that have just appeared in recent years.Although the treatment concepts and methods of breast cancer have made great progress,the fatality rate of breast cancer remains high.The main cause of death of breast cancer patients is that after radiotherapy and chemotherapy,some tumor cells still infiltrate the remote organs,causing Tumor recurrence and distant metastasis,leading to treatment failure.Although we have discovered the basic pathogenesis of breast cancer at the level of molecular biology research,in clinical practice,the complexity of the disease and the choice of chemotherapy regimens still remind us that it is necessary to continue to find and explore the pathogenesis of breast cancer,and Research on the molecular mechanism of its invasion and metastasis has been carried out,so as to develop more effective biomarkers for the early clinical diagnosis and treatment of breast cancer and even the later postoperative prognosis judgment.A large amount of research evidence shows that long non-coding RNA plays an important role in the occurrence,development and progression of tumors.Its biological function and its regulation mechanism on disease are the focus and difficulty of current oncology research.Current research results found that long non-coding RNAs are found in almost all tumor types,and their differential expression is closely related to the malignant biological functions and behaviors of tumors.Therefore,the regulation of long non-coding RNAs in tumors is studied.The mechanism,revealing its internal mechanism of action,can provide us with great help in conquering tumors and even curing tumors.However,due to the difficulty of studying long non-coding RNA,our understanding of long non-coding RNA is relatively lagging.The mechanism of invasion and metastasis in breast cancer is regulated by long non-coding RNA.In this project,we first established a chemotherapy-resistant cell line(MCF-7/ADR)in low-metastatic epithelial breast cancer cells(MCF-7),and then tested its drug resistance to confirm its resistance.After the performance,high-throughput sequencing was used to sequence the transcriptome of MCF-7 cells and MCF-7/ADR cells to screen for differentially expressed long non-coding RNAs.Immediately in breast cancer tissues and adjacent tissues,real-time fluorescent quantitative PCR was used to screen and verify the long non-coding RNA with the most significant differential expression.And determined the stable HIF-1?-stabilizing long noncoding RNA(HIF-1?-stabilizing long noncoding RNA,HISLA)as our final research goal.By collecting the peripheral blood of breast cancer patients,and using real-time fluorescent quantitative PCR to detect the relationship between circulating LncRNA-HISLA in the peripheral blood of breast cancer patients and the clinical characteristics and prognosis of breast cancer patients.Through siRNA interference technology,we interfere with the expression of HIF-1?-stabilizing long noncoding RNA(HISLA)in the drug-resistant cell line MCF-7/ADR,and detect it by fluorescence quantitative PCR Interference efficiency,and then we use CCK-8 to detect changes in drug resistance and proliferation of the drug-resistant cell line MCF-7/ADR,and insert holes to detect changes in sports invasion ability.It was found that after interfering with the expression of HISLA,the drug resistance and proliferation ability of the drug-resistant cell line MCF-7/ADR were inhibited,and the athletic invasion ability was also inhibited.Then,real-time fluorescent quantitative PCR was used to detect the expression of HISLA in 40 breast cancer tissues and 20 paracancerous tissue samples.The results showed that HISLA was significantly up-regulated in breast cancer tissues compared with adjacent tissues.In addition,the high expression of HISLA in breast cancer tissues is significantly associated with the progression of breast cancer patients,including higher breast cancer grades and lymph node metastasis.The expression levels of HISLA in serum between 40 breast cancer patients and 20 healthy control individuals were further compared.Compared with the expression level of the healthy control group,the expression of HISLA in the serum of breast cancer patients was significantly higher.The data also showed that the up-regulation of HISLA in peripheral blood is related to histological grade,TNM staging,distant organ metastasis and HER2 subtype of breast cancer patients.However,there was no significant correlation between serum HISLA level and age and primary tumor size.And the expression of HISLA in the serum of breast cancer patients is positively correlated with the expression of HISLA in breast cancer tissues.ROC curve analysis results show that serum HISLA levels can be used to assess prognostic risk and distinguish breast cancer patients from healthy control patients.The results of Kaplan-Meier prognostic survival analysis showed that the higher the expression level of circulating HISLA in the peripheral blood of breast cancer patients,the shorter the overall prognosis,indicating that elevated circulating HISLA can be used to help accurately predict the worse prognosis of breast cancer patients.A comparison of HISLA expression in serum samples of 20 breast cancer patients undergoing surgery before and after surgery showed that the expression level of HISLA in serum after surgery was significantly lower than that before surgery.In summary,this study used high-throughput sequencing to screen differentially expressed long non-coding RNAs by constructing breast cancer drug-resistant cell lines,further testing and verifying in clinical samples,and analyzing the peripheral blood in combination with clinical prognostic data.The relationship between the expression of long non-coding RNA-HISLA and the clinical prognosis of breast cancer patients.This provides evidence for further exploration of its regulatory function in the occurrence and development of breast cancer,and also provides a new potential drug target for its early diagnosis and postoperative treatment of breast cancer. |
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