ABSTRACT
Tyrosine phosphorylation is one of the important protein phosphorylations in eukaryotes responsible for a variety of biological processes including cell signaling transduction, cell migration, and apoptosis. In the study of phosphoproteomics, due to the low stoichiometry of tyrosine phosphorylation (pTyr) proteins and sometimes limited initial sample, traditional phosphoproteomics enrichment technology is inefficient for the enrichment of pTyr peptides. Here, we review the substantial progress in tyrosine phosphoproteomics by preparation of limited amount sample and the newly introduced SH2 superbinder.
Subject(s)
Cell Movement , Peptides , Phosphorylation , Technology , Tyrosine/metabolismABSTRACT
Tumor has become the second most serious disease that threatens human health and life. Treating with chemical drugs (referred to as chemotherapy) is the most basic treatment, but most chemotherapeutic drugs cause damage to normal tissues. It is a difficult problem in the field of biomedical research that how to deliver anti-tumor drugs more efficiently, increase the concentration of drugs in tumor tissues, enhance the anti-tumor effect, and decrease the drug distribution in normal tissues to weaken the damage to normal tissues. In order to achieve the goals of accurate delivery of anti-tumor drugs and synergism and attenuation, the researchers used systematic evolution of ligands by exponential enrichment technology (SELEX technology) to screen aptamers that can specifically target tumor markers or tumor cells, and designed the novel liposome targeting drug delivery system with aptamers as targeting molecules (ligands). This paper briefly introduced nucleic acid aptamer technology and common tumor markers, and reviewed the research advances on the antitumor effect of aptamer-liposome drug delivery system. It will provide references for the selection of appropriate tumor markers as targets and the application of aptamer technology in the research and development of high-efficiency and low-toxicity liposome targeting agents of anti-tumor traditional Chinese medicine. Meanwhile, it is of great significance for promoting the application of aptamer technology in targeted drug delivery systems.
ABSTRACT
Objective: To establish a macroporous resin enrichment process for total triterpene sapogenins from Pfaffia glomerata,and evaluate the free radical scavenging activity of the total triterpene sapogenins. Methods: The transfer rate of triterpene sapogenins was used as the index. Static adsorption-desorption method was used to select the best macroporous resin,dynamic adsorption-desorption method was used to determine the enrichment process parame- ters,and orthogonal test was used to optimize the enrichment process. The 1,1- diphenyl- 2- trinitrophenylhydrazine (DPPH)and hydroxyl free radical scavenging tests were used to evaluate the free radical scavenging capacity of the triter- pene sapogenins. Results: The AB-8 type macroporous resin had the best enrichment effect on the triterpene sapoge-nins. The conditions for the optimum enrichment process were as follows:the concentration of triterpene sapogenins in the sample solution for resin column chromatography was 3.5 mg/ml,the ratio of diameter to height for the bed of resin column was 1:7,the amount of the raw herbs subjected to the resin column was 0.11 g/ml(herbs/resin),the flow rate for subjecting sample solution to resin column was 1 BV/h,the eluent was 95% aqueous ethanol,the eluting flow rate was 2BV/h,and the eluent volume for elution was 7 BV. After optimization,total triterpene sapogenins reached 65% in the samples prepared by the optimized process,and the transfer rate of total triterpene sapogenins reached 80.23% in the pre- paring process. The total triterpene sapogenin sample could scavenge the DPPH and hydroxyl free radicals,and the scav- enging rate for the DPPH and hydroxyl radicals reached 82.42% and 73.43% at the 1.0 mg/ml,respectively. Conclusion: The AB- 8 macroporous resin can be used for the enrichment and purification of triterpene sapogenins from P. glomerata. The optimized enrichment process was stable and feasible,and the obtained triterpene sapogenins showed a good free radical scavenging activity.
ABSTRACT
Nucleic acid aptamer is an oligonucleotide sequence screened by the exponential enrichment ligand system evolution technology (SELEX). Previous studies have shown that nucleic acid aptamer has a good application prospect in tumor diagnosis and treatment. Therefore, we reviewed the selection and identification of nucleic acid aptamer of lung cancer cells in recent years, and discussed the effect of aptamer as targeting drugs and targeting vectors on the diagnosis of tumors, which provide a new idea for early diagnosis and treatment of tumor.
ABSTRACT
Objective To introduce a new method for preparation of bioactive β-tricalcium phosphate (β-TCP) by rapid stem cell screen-and-enrich-and-combine circulating system (SECCS) and evaluate its efficacy in the treatment of fresh fractures and bone defects.Methods Twenty-two patients with fresh fracture and bone defects were treated with SECCS from July 2013 to April 2016.They were 16 males and 6 females with an average age of 52.2 years (from 27 to 81 years).There were 15 tibial plateau fractures and 7 calcaneal fractures.The average size of bone defects was 12.5 mL.Bioactive β-TCP was prepared by SECCS intraoperatively and implanted back immediately into the bone defects.Radiographic examination,Lysholm knee scoring and Maryland foot scoring were used for assessment of curative efficacy.Results The 22 patients were followed up for an average of 25.7 months (from 12 to 46 months).By SECCS,the enrichment efficiency of bone marrow stromal cells (BMSCs) reached up to 82.4％ and the cell viability was not affected.The tibial plateau fractures were re-transplanted with 13,381.3 BMSCs on average and healed after an average of 8.9 weeks (from 6 to 15 weeks).The Lysholm knee scores at one year postoperatively averaged 93.6 points (from 84 to 100 points),yielding 10 excellent cases,4 good cases and one fair case.The calcaneal fractures were implanted back with 16,677.7 BMSCs on average and healed after an average of 9.4 weeks (from 8 to 13 weeks).The average Maryland foot score at one year after operation was 93.6 points (from 85 to 98 points),yielding 6 excellent cases and one good case.Conclusion Bioactive materials prepared by SECCS are good bone grafts for fresh fractures and bone defects.