Rapid tumor cell growth depends on intracellular polyamine levels higher than those of normal cells. Intracellular polyamine depletion inhibits tumor cell proliferation and induces tumor cell apoptosis. Therefore, polyamine metabolism has recently been identified as an important target for anti-tumor therapy. This article briefly summarizes recent polyamine metabolism targeting, polyamine depletion within the tumor cells through a variety of methods, and the antitumor effects of the treatment.

As a major adhesion molecule of endothelial junction, vascular endothelial cadherin (VE-cadherin) plays a very important role for the maintenance of vascular homeostasis. It regulates infiltration of vascular endothelia on contents in plasma such as eukocytes and lipid, as well as cellular proliferation and apoptosis. It plays an important role by involving in angiogenesis in the multiple links of the process of atherosclerosis, This article reviews the recent progress in research on the effects and mechanisms of VE-cadherin in the occurrence and developmaent of atherosclerosis in recent years.

Atherosclerosis is the major cause of ischemic stroke.Given the importance of the early diagnosis and intervention of atherosclerotic plaques,the use of molecular imaging techniques for early diagnosis of atherosclerosis has become a research focus in recent years.This article reviews the advances in research on molecular imaging in the aspect of early diagnosis of atherosclerosis.

Transient ischemic attack(TIA)is known as a risk warning signal of cerebral infarction. In order to screen the patients with high risk of TIA rapidly and give them correct and timely treatment, and thus prevent stroke, this article reviews the etiology, pathogenesis, clinical manifestation and imaging that affect on TIA, and the more commonly used prognostic rating scales at present.

Objective To investigate whether difluromethylornithine (DFMO) can be used in the treatment of human leukemia. Methods The cell proliferation was detected by MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium)] assay after treatment of human lymphocyte Jurkat cells by DFMO (0 to 10 mmol/L) for 24 to 72 h. Enzyme activity of spermine oxidase (SMO) and acetylpolyamine oxidase (PAO) was determined by chemiluminesence assay. DNA fragmentation assay was used to evaluate cell apoptosis. Fluorescent dye assay was performed to determine the changes in mitochondrial membrane potential. Western blotting was used to determine Bax content. Casepase-3 enzyme activity was measured by spectrophotometric method. Results DFMO treatment inhibited the proliferation of Jurkat cells significantly in a dosage- and time-dependent manner (P

Objective To investigate the effect of the new polyamine analogue tetrabutyl propanediamine (TBP) on cell proliferation and the underlying mechanism. Methods MTT assay was performed to determine cell proliferation. Flow cytometry was performed to detect cell cycle transition. DNA fragmentation and mitochondrial membrane potential determinations were performed to detect cell apoptosis. The activity of key enzymes in polyamine catabolism was detected by chemiluminescence assay. Results TBP could significantly inhibit the proliferation of HL-60 cells by blockingcell cycle transition and by inducing apoptosis. The TBP-induced apoptosis of HL-60 cells was in a dose-dependent manner. The enzyme activities of SMO and APAO were also significantly increased in HL-60 cells after treatment with 100 μM TBP for 24 hours. Conclusions TBP, as a new putrescine analogue, could inhibit proliferation of HL-60 cells by increasing the enzyme activity of SMO and APAO and inducing apoptosis.

Aim To study the effects of polyamine analogue CPENSpm on the human lung cancer line A549 in cell proliferation and apoptosis.Methods MTS was used to assay the cell proliferation,chemical analysis methods were used to determine the activities of enzymes in the polyamine metabolism,HPLC was performed to assay the intracellular concentration of polyamines,Sub-G1 and DNA fragmentation assays were used to determine the cell apoptosis.Results Treating A549 lung cancer cells by CPENSpm resulted in:①cell-growth inhibition and cell apoptosis;②inhibition of ODC(key enzyme in polyamine synthetic pathway)and activation of SSAT and SMO(key enzymes in polyamine catabolism);③great decrease of intracellular polyamine concentrations.MDL72527,the SMO inhibitor,can antagonize the effect of CPENSpm on inhibiting the proliferation of A549 cells.Conclusion CPENSpm inhibits proliferation and induces apoptosis of human A549 lung cancer cell line by interfering the polyamine metabolism,depleting intracellular polyamine contents that are need by quick-growth of cancer cells and inducing production of H2O2.

AIM: To prepare recombinant human spermine oxidase (SMO) and polyclonal antibody against human SMO by gene recombination techniques. METHODS: Human SMO cDNA was amplified from total RNA of A549 cells through reverse transcription PCR. The cDNA was then cloned into pET-15b to construct SMO prokaryotic expression vector. After transforming, the vector was induced to express recombinant SMO by IPTG in E. coli BL21 (DE_3). Recombinant SMO was purified by Ni-NTA resin under denaturing condition and then was dialyzed to renature. The enzyme activity of recombinant SMO was analyzed by chemical fluorescent method. SMO polyclonal antibody was prepared by using recombinant human SMO protein purified by polyacrylamide gel electrophoresis as antigen to inoculate rabbit intradermally. The titer and specificity of anti-sera were determined by ELISA, Western blot and Immune Cell Chemistry. RESULTS: Purified and dialyzed recombinant human SMO has the specificicity of oxidizing the spermine. The polyclonal antibody has high titer and specificity against human SMO. CONCLUSION: This research established a method for prokaryotic expression, purification and polyclonal antibody preparation of human SMO. The method lays a foundation for the future functional research of SMO.

To investigate the relationship among serum vascular endothelial cells(VE) -cadherin, advanced glycation end-products( AGE), and atherosclerotic lesion. 20 healthy subjects and 60 patients with diabetes mellitus,including 30 patients with carotid atherosclerosis (CI), were enrolled.Soluble VE-cadherin and AGE were determined using the enzyme-linked immunosorbent method (ELISA). The relationships among the concentration of soluble VE-cadherin, AGE, and the course of the disease, blood glucose, and blood lipid levels were analyzed with multivariant stepwise regression analysis. The levels of serum VE-cadherin and AGE in the patients with diabetes and CI were higher than those in control group( P＜0. 05 ). There was a significant difference in VE-cadherin between the diabetes group and the CI group( P＜0. 05 ). Serum VE-cadherin levels were positively correlated with serum AGE levels(r = 0. 69, P＜0. 01 ). AGE levels were positively correlated with the diabetes duration ( r = 0. 31, P =0. 02 ). The levels of serum VE-cadherin in diabetic patients are positively correlated with their serum AGE levels. The VE-cadherin seems to play an important role in the development of atherosclerosis caused by AGE.

BACKGROUND: Demineralized bone matrix (DBM) has natural mesh pores, good plasticity and biocompatibility. However, the decalcification time in preparation of DBM remains controversial.OBJECTIVE: To compare effects of varying degrees of decalcification with DBM on the proliferation of bone marrow stromal stem cells (BMSCs) so as to provide the best DBM scaffold for cartilage tissue engineeringMETHODS: Rabbit iliac bones were prepared into strips, defatted, followed by 6,12 and 24 hours of decalcification and 2 days of soaking in alcohol to prepare DBM. DBMs were placed in 24-well plates. The third passage of BMSCs at a density of 5×10~9/L were incubated on 24-well plate with DBMs. The DBM porosity and pore size were observed by scanning electron microscopy;BMSCs proliferation on the DBM was determined by MTT, and cell attachment on DBM was observed by scanning electron microscopy.RESULTS AND CONCLUSION: DBM displayed natural high-density porous grid structure, in the presence of bone trabecula,trabecular space and bone luminal system. The porosity and pore size of DBM decalcified for 6,12 and 24 hours were similar (P > 0.05). Compared with decalcified for 12 and 24 hours, BMSCs attached to DBM decalcified for 6 hours more closely and the DBM showed better compatibility. SEM observation showed the BMSCs on DBMs decalcified for 6 hours proliferated stably after 8 days and applicable for transplantation. Moreover, the number of cells were significantly more than DBMs decalcified for 12 and24 hours (P< 0.01).