Drug target discovery by magnetic nanoparticles coupled mass spectrometry / 药物分析学报

Drug target discovery is the basis of drug screening.It elucidates the cause of disease and the mechanism of drug action,which is the essential of drug innovation.Target discovery performed in biological sys-tems is complicated as proteins are in low abundance and endogenous compounds may interfere with drug binding.Therefore,methods to track drug-target interactions in biological matrices are urgently required.In this work,a Fe3O4 nanoparticle-based approach was developed for drug-target screening in biofluids.A known ligand-protein complex was selected as a principle-to-proof example to validate the feasibility.After incubation in cell lysates,ligand-modified Fe3O4 nanoparticles bound to the target protein and formed complexes that were separated from the lysates by a magnet for further analysis.The large surface-to-volume ratio of the nanoparticles provides more active sites for the modification of chemical drugs.It enhances the opportunity for ligand-protein interactions,which is beneficial for capturing target proteins,especially for those with low abundance.Additionally,a one-step magnetic separation simplifies the pre-processing of ligand-protein complexes,so it effectively reduces the endogenous interference.Therefore,the present nanoparticle-based approach has the potential to be used for drug target screening in biological systems.

miR-29a in Exosomes from Bone Marrow Mesenchymal Stem Cells Inhibit Fibrosis during Endometrial Repair of Intrauterine Adhesion

Background and Objectives@#Bone marrow mesenchymal stem cells (BMSCs) is an ideal source of stem cells in the treatment of intrauterine adhesion. Exosomes are a type of membrane vesicle and the diameter is 30∼100 nm. Exosomes can take their contents into the target cells, releasing and exerting their functions. In this study, we intend to study the role of human BMSC-derived exosomes (BMSC-Exo) in promoting endometrial damage repair in the treatment of IUA. @*Methods@#We used the magnetic bead affinity method to extract BMSC-Exo and analyzed its biological character. Then we co-cultured the BMSCs-Exo with endometrial cells to detect its effect. We injected BMSCs-Exo into the IUA mouse model. We over-expressed miR-29a in BMSCs-Exo by transient transfection, then used RT-PCR to analyze the expression of the related genes. @*Results@#BMSCs-Exo expressed exosome-specific proteins CD9, CD63, and CD81. BMSCs-Exo could bring the contents into the target cells. BMSCs-Exo can promote endometrial repair in vitro or in vivo. BMSCs-Exo overexpressing miR-29a can reduce αSMA, Collagen I, SMAD2, and SMAD3. @*Conclusions@#In this study, we successfully isolated BMSCs-Exo and proved its character and biological activity. BMSCs-Exo can promote cell proliferation and cell migration in vitro and can repair damaged endometrium in the IUA model. The presence of miR-29a in BMSCs-Exo may be an important factor in its resistance to fibrosis during endometrial repair of IUA. This study provides new ideas for the treatment of patients with IUA and has important clinical research significance.

Correlation between K-ras gene mutation and clinicopathological characteristics and prognosis of colorectal cancer patients with different primary sites / 肿瘤研究与临床

Objective To analyze the correlation between K-ras gene mutation and clinicopathological characteristics and prognosis of colorectal cancer patients with different primary sites.Methods The clinical and pathological records of 69 patients who were pathologically confirmed as colorectal cancer and tested K-ras gene status at Wuxi People's Hospital Affiliated to Nanjing Medical University between May 2007 and August 2017 were adopted.The correlation between clinicopathological characteristics and prognosis of colorectal cancer patients with different primary sites and K-ras gene mutation status were retrospectively analyzed.And the patients were visited to adopt the prognosis data and perform the Kaplan-Meier survival analysis.Results The K-ras mutation rate was 50.7％(35/69),including 40.0％(12/30)in left-side colon cancer,73.3％(11/15)in right-side colon cancer and 50.0％(12/24)in rectal cancer.The mutation rate of K-ras gene in patients ≥ 60 years old [61.5％(24/39)vs.36.7％(11/30),χ2= 4.197,P = 0.041] or serum CA19-9 raising up abnormally was conspicuously high [65.6％(19/29)vs.37.5％(15/40),χ 2= 5.486,P =0.019].Other clinicopathological characteristics,such as gender,lesion location,histological classification,TNM stage,serum CEA expression,clinical features had no correlation with K-ras gene mutation status(all P＞ 0.05).And no relationship was found between prognosis and overall survival of colorectal cancer patients with different primary sites and K-ras gene mutation status(χ 2= 0.001,P = 0.997; χ 2= 0.583,P =0.445).In general,the 5-year survival rate of left-side colon cancer patients was highest(76.9％),followed by rectal cancer(69.7％),and right-side colon cancer was lowest(31.3％).The primary site of colorectal cancer was related to the overall survival of patients(χ2=11.004,P =0.004).Conclusions K-ras gene mutation in colorectal cancer is closely related to age and serum CA19-9 levels of the patients.The prognosis of left-side colon cancer is best,rectal cancer second,and right-side colon cancer poorest.Whether K-ras gene mutation is the prognostic factor of colorectal cancer is not clear.Testing the K-ras gene status and serum tumor index expression,distinguish the primary site and age group will provide the theory basis and promote the clinical targeted therapy and improve the survival of colorectal cancer patients.