EEN regulates the proliferation and survival of multiple myeloma cells by potentiating IGF-1 secretion

The molecular mechanisms of multiple myeloma are not well defined. EEN is an endocytosis-regulating molecule. Here we report that EEN regulates the proliferation and survival of multiple myeloma cells, by regulating IGF-1 secretion. In the present study, we observed that EEN expression paralleled with cell proliferation, EEN accelerated cell proliferation, facilitated cell cycle transition from G1 to S phase by regulating cyclin-dependent kinases (CDKs) pathway, and delayed cell apoptosis via Bcl2/Bax-mitochondrial pathway. Mechanistically, we found that EEN was indispensable for insulin-like growth factor-1 (IGF-1) secretion and the activation of protein kinase B-mammalian target of rapamycin (Akt-mTOR) pathway. Exogenous IGF-1 overcame the phenotype of EEN depletion, while IGF-1 neutralization overcame that of EEN over-expression. Collectively, these data suggest that EEN may play a pivotal role in excessive cell proliferation and insufficient cell apoptosis of bone marrow plasma cells in multiple myeloma. Therefore, EEN may represent a potential diagnostic marker or therapeutic target for multiple myeloma.     

人工核酸内切酶介导的新一代基因组编辑技术进展

对基因组特定位置进行针对性修饰的实验方法称为基因组编辑技术。近年出现的ZFN、TALEN、CRISPR/Cas等一系列人工核酸内切酶逐渐形成了新一代基因组编辑技术,极大地促进了基因组靶向修饰技术的发展,并在基因功能研究、基因治疗等领域开始发挥巨大作用。文中对这一技术的基本原理、发展历程和应用方式进行了简要总结。     

早期肠内营养对胃癌根治术患者术后恢复和免疫功能的影响

目的:评价早期肠内营养(EEN)对胃癌根治术患者术后恢复和免疫功能的影响。方法:选入2011年6月～2014年1月在我院行胃癌根治术治疗的患者60例,根据术后营养方式不同分为EEN组和全肠外营养支持(TPN)组,每组30例。比较两组患者机体恢复及免疫功能情况。术后随访3年,观察并记录两组无进展生存率和总生存率。结果:EEN组术后排气时间[(2.46±0.78)d vs(3.85±1.03)d]、排便时间[(4.03±1.17)d vs(5.67±1.23)d]、进流质时间[(5.88±1.30)d vs(7.26±1.59)d]、进半流食时间[(7.94±1.85)d vs(11.01±2.36)d]和住院天数[(14.87±2.56)d vs(17.54±3.30)d]均显著短于TPN组,差异均有统计学意义(P0.05)。术后第1d,两组各项体液免疫指标(Ig A、Ig G、Ig M浓度)和细胞免疫指标(CD3+、CD4+和CD4+/CD8+水平)均显著下降(P0.05),营养支持后逐渐恢复,而EEN组恢复幅度较TPN组大,差异具有统计学意义(P0.05)。EEN组术后并发症总发生率显著低于TPN组(13.33%vs 36.67%,P0.05)。EEN组患者1年、2年和3年无进展生存率和总生存率均稍高于TPN组,但差异无统计学意义(P0.05)。结论:EEN可有效促进胃癌根治术患者的肠功能恢复,缩短住院时间,提高机体免疫功能,降低并发症的发生,值得在临床推荐应用。     

人EEN蛋白的结构预测和功能分析

采用基于神经网络的算法预测了我们自行克隆的新的白血病相关蛋白ＥＥＮ（ｅｘｔｒａ ｅｌｅｖｅｎｎｉｎｅｔｅｅｎ, ＥＥＮ）全长分子的二级结构,结果表明：ＥＥＮ 蛋白可能有三个结构域,Ｎ 端由三段α螺旋和短β折叠组成,中间为四段α螺旋组成的四螺旋结构,Ｃ端为ＳＨ３结构域,类似于在受体酪氨酸激酶信号传导途径中起重要作用的ＳＥＭ－５／ＧＲＢ２ Ｃ端ＳＨ３结构域;利用同源蛋白结构模拟的方法,模拟了ＥＥＮ ＳＨ３结构域的三维结构,结果表明：ＥＥＮ ＳＨ３结构域与ＳＥＭ－５／ＧＲＢ２ ＳＨ３结构域具有相近的结构,构成脯氨酸结合区的氨基酸非常保守．上述结果提示：ＥＥＮ 蛋白可能为新的信号蛋白,可能涉及新的信号传导途径或新的信号传导旁路,ＳＨ３结构域是其功能区域．     

The major pathway by which polymeric formula reduces inflammation in intestinal epithelial cells: a microarray-based analysis

Nutritional therapy is well established as a means to induce remission in active Crohn’s disease (CD). Evidence indicates that exclusive enteral nutrition (EEN) therapy for CD both alters the intestinal microbiota and directly suppresses the inflammatory response in the intestinal mucosa. However, the pathway(s) through which EEN suppresses inflammation is still unknown. Therefore, the aim of the current study was to use microarray technology to investigate the major pathway by which polymeric formula (PF) alters inflammatory processes in epithelial cells in vitro. HT-29 cells were grown to confluence and then co-cultured with tumour necrosis factor (TNF)-α (100 ng/ml) for 5 h in the presence or absence of PF, as used for EEN. Following incubation, RNA was extracted and subjected to polymerase chain reaction (PCR) and microarray analysis. Enzyme-linked immunosorbent assays were employed to evaluate cytokine protein levels. Neither TNF-α nor PF had a toxic effect on cells over the experimental period. Microarray analysis showed that PF modulated the expression of genes specifically linked to nuclear factor (NF)-κB, resulting in downregulation of a number of genes in this pathway. These findings were further confirmed by real-time PCR of selected dysregulated genes as well as reduced expression of IL-6 and IL-8 proteins following PF treatment. The results arising from this study provide evidence that PF alters the inflammatory responses in intestinal epithelial cells through modulation of the NF-κB pathway.

Electronic supplementary material

The online version of this article (doi:10.1007/s12263-015-0479-x) contains supplementary material, which is available to authorized users.