INTRODUCTION The antitumor activity of norcantharidin (NCTD),the demethylated analogue of cantharidin, was studied in the early 1980s in China. NCTD has no side effects on urinary organs which cantharidin has shown and is easier to synthesize, and it can inhibit the proliferation of several tumor cell lines as well as transplanted tumors. Clinical trials with NCTD as a monotherapeutic agent indicated that NCTD had beneficial effects in patients with different kinds of digestive tract cancers, such as primary hepatoma,carcinomas of esophagus and gastric cancer, but no depressive effect on bone marrow cells. NCTD can increase the white blood cell count by stimulating the bone marrow and has some antagonistic effect against leukopenia caused by other agents. The exact cellular and molecular mechanisms of NCTD on tumor cells have not yet been elucidated to date[1-3].

Objective: To investigate the post-transcriptional regulation of p21WAF1/CIP1 by p53. Methods: The MDA-MB-468 cells have endogenous mutant p53 and the MCF7 cells lines have wtp53. Recombinant p53 expression and p21WAF1/CIP1 induction were detected by Western blot analysis. Northern blot analysis was carried out to examine whether changes in p21WAF1/CIP1 protein levels in MCF7 cells treated with AdCMVp53 are reflected at the mRNA level. Flow cytometric analysis of MCF7 cells following overexpression of recombination. Results: The ratio of p53: p21WAF1/CIP1 was below 1 at the early stages of AdCMVp53 infection, but increased to 1.6 by day 3 and to 9.7 by day 5 post-infection. As expected, p21WAF1/CIP1 expression was not detectable in MDA-MB-468 cells despite the presence of high levels of mutant p53 protein. The G1/S ratios in untreated controls and AdCMVβgal infected MCF7 cells were 1.10 and 1.35, respectively. By Northern blot analyzing the p21WAF1/CIP1: GAPDH ratios at different time points against the ratio at time point 0, a maximum 3-fold induction of p21WAF1/CIP1 mRNA expression relative to untreated control was observed on day 1 post-infection. The flow cytometric analysis indicated that MCF7 cells infected with AdCMVp53 undergo G1 arrest at both time points studied, with G1/S ratios ranging from 5.54 at day 1 to 5.65 at day 7. The G1/S ratios in untreated controls and AdCMVβgal infected MCF7 cells were 1.10 and 1.35, respectively. Conclusion: This studydemonstrated that p53 could regulate p21WAF1/CIP1 gene expression at both the transcriptional and post-transcriptional levels in MCF7 cells. The latter mechanism may be involved in or be responsible for, the induction of cell cycle arrest by transcription-defective mutants of p53.

Peripheral and central sensitizations are phenomena that occur during migraine. The role of pentin, a migraine preventive drug, on central sensitization remains unclear. In this study, a rat model of migraine was established by electrical stimulation of the trigeminal ganglion, and the an-imals were given intragastric gabapentin. Changes in amino acid content in the cerebrospinal fluid and protein kinase C membrane translocation in the spinal trigeminal nucleus were examined to clarify the mechanisms underlying the efficacy of gabapentin in the treatment of central sensitization during migraine. Electrophysiology, liquid chromatography-mass spectrometry and western blot analysis results revealed that gabapentin reduces neuronal excitability in the spinal nucleus in the trigeminal nerve, decreases excitatory amino acid content and inhibits the activation of protein ki-nase C. This provides evidence that excitatory amino acids and protein kinase C are involved in the formation and maintenance of central sensitization during migraine. Gabapentin inhibits migraine by reducing excitatory amino acid content in the cerebrospinal fluid and inhibiting protein kinase C ac-tivation.

Prenatal alcohol exposure disrupts the development of normal fetal respiratory function, but whether it perturbs respiratory rhythmical discharge activity is unclear. Furthermore, it is un-known whether the 5-hydroxytryptamine 2A receptor (5-HT2AR) is involved in the effects of prenatal alcohol exposure. In the present study, pregnant female rats received drinking water containing alcohol at concentrations of 0%, 1%, 2%, 4%, 8% or 10% (v/v) throughout the gestation period. Slices of the medulla from 2-day-old neonatal rats were obtained to record respiratory rhythmical discharge activity. 5-HT2AR protein and mRNA levels in the pre-B?tzing-er complex of the respiratory center were measured by western blot analysis and quantitative RT-PCR, respectively. Compared with the 0% alcohol group, respiratory rhythmical discharge activity in medullary slices in the 4%, 8% and 10% alcohol groups was decreased, and the reduc-tion was greatest in the 8% alcohol group. Respiratory rhythmical discharge activity in the 10%alcohol group was irregular. Thus, 8% was the most effective alcohol concentration at attenuating respiratory rhythmical discharge activity. These ifndings suggest that prenatal alcohol exposure attenuates respiratory rhythmical discharge activity in neonatal rats by downregulating 5-HT2AR protein and mRNA levels.

Our previous findings confirmed that the nerve growth factor-containing fibrin glue membrane pro-vides a good microenvironment for peripheral nerve regeneration;however, the precise mechanism remains unclear. p75 neurotrophin receptor (p75NTR) plays an important role in the regulation of pe-ripheral nerve regeneration. We hypothesized that a nerve growth factor-containing fibrin glue membrane can promote neural regeneration by up-regulating p75NTR expression. In this study, we used a silicon nerve conduit to bridge a 15 mm-long sciatic nerve defect and injected a mixture of nerve growth factor and fibrin glue at the anastomotic site of the nerve conduit and the sciatic nerve. Through RT-PCR and western blot analysis, nerve growth factor-containing fibrin glue membrane significantly increased p75NTR mRNA and protein expression in the Schwann cells at the anasto-motic site, in particular at 8 weeks after injection of the nerve growth factor/fibrin glue mixture. These results indicate that nerve growth factor-containing fibrin glue membrane can promote pe-ripheral nerve regeneration by up-regulating p75NTR expression in Schwann cells.

ANXA2调节胃癌细胞的增殖、侵袭和转移

目的：Annexin a2(ANXA2)基因参与多种生物学活动。然而，ANXA2在胃癌中的临床意义及生物学作用仍然未明。方法：免疫组化染色的方法定量检测了胃癌组织及癌旁正常胃黏膜组织中ANXA2蛋白的表达情况。通过实时定量PCR及免疫印迹的方法分析了四种不同分化程度的胃癌细胞系SGC-7901, MKN-45, BGC-823和AGS中ANXA2的表达情况。通过LV-ANXA2-RNAi慢病毒干扰AGS细胞ANXA2的表达。利用MTT、克隆形成实验检测细胞增殖情况。通过流式细胞术细胞凋亡、细胞周期实验分析细胞死亡情况。利用细胞划痕实验、细胞侵袭小室及transwell实验检测细胞的侵袭和转移的情况。然后，用表达谱芯片进行筛选，通过免疫印迹实验阐明沉默ANXA2基因对c-met和RAP1A表达的影响。结果：免疫组化染色实验发现相较于癌旁正常的胃黏膜组织，胃癌组织中ANXA2蛋白表达量明显增高，并且ANXA2的表达与胃癌患者的临床特性密切相关。在这四种胃癌细胞系中ANXA2均高表达，其中AGS细胞ANXA2的表达量高。选取AGS细胞作为细胞模型继续进行后续的实验。用慢病毒干扰的AGS细胞，其ANXA2基因的表达明显受到抑制。沉默ANXA2基因通过下调c-met的表达抑制了AGS胃癌细胞的增殖并促进其死亡，并通过下调RAP1A的表达抑制AGS胃癌细胞的侵袭和转移。结论：本实验研究发现ANXA2的过表达与胃癌患者的临床分期及不良生存预后相关。ANXA2的过表达与胃癌患者的临床分期及不良生存预后相关。沉默ANXA2基因可以抑制胃癌细胞的增殖、促进其死亡，并影响胃癌细胞的运动能力。

AIM:Increasing evidence suggests that carbohydrate-binding proteins play an essential role in tumor growth and metastasis .Ga-lectin-3, a multifunctional protein of an expanding family of β-galactoside-binding animal lectins , is the major nonintegrin cellular laminin-binding protein , and is implicated in a variety of biologic events , such as inflammation and angiogenesis .Because galectin-3 expression was shown to participate in mediating tumor angiogenesis and initiate signaling cascades in several diseases .We hypothe-sized that galectin-3 may promote pulmonary vascular endothelial neovascularization .METHODS:Hypoxic and MCT rat model of pul-monary artery remodeling was used .The mRNA and protein levels of galectin-3 in rats were measured by in situ hybrization and West-ern blot analysis.Endothelial cell (EC) proliferation, migration and tube formation were measured using MTT , cell scratch and Matri-gel assays, respectively.Protein expression was quantitated by Western blot analysis .LC 3A/B staining was detected with cellular im-munofluorescence staining .RESULTS:We found that galectin-3 was localized on the intima and adventitial wall .Galectin-3 was in-creased after rat hypoxia and MCT administration .Galectin-3 promoted EC proliferation , migration and tube formation , while its roles were reversed by RNA interference.Galectin-3 induced Atg 5, Beclin-1, LAMP-2, and LC 3A/B expression increases.Galectin-3 al-so increased LC 3A/B staining in ECs.Akt/mTOR and GSK-3βsignaling pathways were activated after galectin-3 treated ECs using its specific phosphorylation antibodies , while blocked it with LY294002 inhibited cell autophagy and EC dynamic alterations induced by galectin-3.CONCLUSION:These findings demonstrate that galectin-3 can induce an Akt signaling cascade leading to cell autoph-agy, and then the differentiation and angiogenesis of pulmonary artery endothelial cells .

AIM:To investigate the effects of human induced pluripotent stem cell-derived exosomes (hiPSC-exo) on cell viability, capillary-like structure formation , and senescence in endothelial cells exposed to high glucose .METHODS: Exosomes were isolated from the conditional medium of hiPSCs and confirmed by transmission electron microscopy , nanoparticle tracking analysis , and Western blot analysis using Alix and CD63 as markers.hiPSC-exo were labeled with PKH26 for tracking.Cultured HUVECs were treated with high glucose (33 mmol/L) with or without hiPSC-exo (20 mg/L) for 48 h, and cell viability, capillary tube formation, and senescence were assessed .RESULTS:hiPSC-exo showed a typical cup shape and could be taken up by human umbilical vascular endothelial cells (HUVECs) in a concentration-dependent manner.When exposed to high glucose, viability and tube formation in HUVECs was signifi-cantly reduced, whereas the proportion of senescent cells was higher compared to that in control HUVECs (P<0.01).Furthermore, hiPSC-exo restored cell viability and capillary-like structure formation , and reduced senescence in HUVECs exposed to high glucose (P<0.01).However, hiPSC-exo had minimal effects on normal HUVECs.Therefore, stem cell-derived exosomes can promote cell proliferation, enhance capillary-like structure formation , and reduce senescence in endothelial cells exposed to high glucose . CONCLUSION:Our study highlights the role of exosomes derived from hiPSC and may provide a new strategy for maintaining vascular health, preventing vascular aging , and avoiding pathological vascular remodeling that occurs in many diseases .