ABSTRACT
@#【Objective】To screen survival-related differential expression of long non-coding RNA（lncRNA）and its co-expressed genes in breast cancer patients and to verify their expression in breast cancer cells.【Methods】RNA-seq data of 943 cases（837 breast cancer + 106 normal controls）by the TCGA database were screened，and found that long non-coding MAPT-AS1 highly expressed，and breast cancer patients had longer survival. The long non-coding MAPT- AS1 overexpression and interference plasmid was constructed，and the constructed plasmid was transfected into breast cancer cell line T47D，and the stably expressed T47D cell line was screened by puromycin. The expression of long non-coding MAPT-AS1 and its co-expressed genes was verified by the methods of RT-qPCR.【Results】Fluorescence microscopy and RT-qPCR confirmed that the long non-coding MAPT-AS1 overexpression and interference-transfected breast cancer cell line T47D were successfully constructed，and the long non-coding MATS-AS1 interference fragment shRNA3 with the highest interference efficiency was screened. The expression of MAPT ，MAPT- IT1 and NXNL2 in the co-expressed gene was decreased after transfection of the shRNA3 interference fragment ，which was consistent with the expression trend of the long non-coding MAPT-AS1.【Conclusion】The long non-coding MAPT-AS1 overexpression and interference plasmid transfected breast cancer cell line T47D were successfully constructed，and the expression of the co- expressed gene was consistent with the database. The study laid the foundation for further study of the mechanism of action of long non-coding MAPT-AS1 gene in breast cancer.
ABSTRACT
OBJECTIVE@#Larotaxel is a new chemical structure drug, which has not been marketed worldwide. Accordingly, the standard identification and quantification methods for larotaxel remain unclear. The spectrometric analyses were performed for verifying weight molecular formula, molecular weight and chemical structure of larotaxel. Besides, a quantification method was developed for measuring larotaxel in the liposomes.@*METHODS@#The molecular formula, molecular weight and chemical structure of larotaxel were studied by using mass spectrometry (MS), infra-red (IR), nuclear magnetic resonance (NMR) and ultraviolet-visible (UV-vis) spectrometric techniques. The absorption wavelength of larotaxel was investigated by UV-vis spectrophotometry full-wavelength scanning. Besides, a quantification method was developed by high performance liquid chromatography (HPLC), and then validated by measuring the encapsulation efficacy of larotaxel liposomes.@*RESULTS@#The four spectral characteristics of larotaxel were revealed and the corresponding standard spectra were defined. It was confirmed that larotaxel had the structure of tricyclic diterpenoids, with the molecular formula of C45H53NO14, the molecular weight of 831.900 1, and the maximum absorption wavelength of 230 nm. The quantitative method of larotaxel was established by using HPLC with a reversed phase C18 column (5 μm, 250 mm×4.6 mm), a mobile phase of acetonitrile-water (75:25, volume/volume), and a detection wavelength of 230 nm. The validation study exhibited that the established HPLC method was stable, and had a high recovery and precision in the quantitative measurement of larotaxel in liposomes. In addition, a new kind of larotaxel liposomes was also successfully prepared. The particle size of the liposomes was about 105 nm, with an even size distribution. And the encapsulation efficiency of larotaxel in the liposomes was above 80%.@*CONCLUSION@#The present study offers reference standard spectra of larotaxel, including MS, IR, NMR, and UV-vis, and confirms the molecular formula, molecular weight and chemical structure of larotaxel. Besides, the study develops a rapid HPLC method for quality control of larotaxel liposomes.