APC、β-catenin 和c-myc 在大肠癌中的表达及其意义

 目的 探讨APC、β-catenin和c-myc在大肠癌发生、发展中的作用。方法 采用免疫组化方法检测30例正常大肠黏膜、30例大肠腺瘤、10例大肠腺瘤恶变及50例大肠癌组织中APC、pcatenin和c-myc蛋白的表达情况。结果 大肠癌和大肠腺瘤恶变APC阳性率分别为44．0％、40．0％，显著低于大肠腺瘤（86．7％）和正常大肠黏膜（100％）（P〈0.01）。大肠癌、大肠腺瘤恶变和大肠腺瘤β-catenin胞浆和（或）胞核异位表达率分别为62．0％、50．0％、30．0％，显著高于正常大肠黏膜（0）（P〈0.01），大肠癌8Icatenin异位表达率显著高于大肠腺瘤（P〈0.01）。大肠癌、大肠腺瘤恶变、大肠腺瘤c-myc阳性率分别为56．0％、60．0％、46．7％，显著高于正常大肠黏膜（0）（P〈0.01）。大肠癌中8-catenin膜表达缺失率为：46．0％，显著高于大肠腺瘤（10．0％）和正常大肠黏膜（0）（P〈0.01），且与大肠癌组织分化程度、浸润深度、淋巴结转移、Dukes分期有关。APC蛋白表达与大肠癌组织分化程度有关。大肠癌中8Icatenin异位表达与c-myc阳性表达呈正相关关系（r=0．63，P〈0.01），而与APC阳性表达呈负相关关系（r=一0．39，P％0．05）。结论 APC失表达和（或）pcatenin异位表达，激活癌基因c-myc过表达与大肠癌的发生、发展密切相关，可能是大肠癌发生的早期事件；pcatenin膜表达缺失与大肠癌的侵袭、转移有关。     

APC基因的DNA甲基化与卵巢癌关系荟萃分析

目的：进一步探讨结肠腺瘤性息肉病基因（APC基因）的失活在卵巢癌的发生、发展中的作用。方法：搜索PubMed、EMBase、Web of Science及CNKI数据库中2000年1月1日—2014年12月31日有关APC基因甲基化与卵巢上皮癌相关的文献,纳入研究均为包含病例组及对照组的随机对照试验。纳入文献采用纽卡斯尔-渥太华量表（NOS）评价标准。使用Stata 11.0软件进行OR值、异质性及发表性偏倚的相关的统计学分析。结果：共纳入9篇文献,其中包括641例卵巢癌患者和377例对照者。总病例组与总对照组的APC基因甲基化发生率差异有统计学意义（OR=6.19,95%CI：4.08～9.41,P=0.000）;卵巢癌组织与正常组织的APC基因甲基化发生率差异有统计学意义（OR=5.88,95%CI：3.66～9.45,P=0.000）;卵巢癌组织与良性卵巢肿瘤组织的APC基因甲基化发生率差异有统计学意义（OR=6.99,95%CI：3.12～15.64,P=0.000）。结论：APC基因甲基化可能与卵巢癌有关。     

Familial adenomatous polyposis in two brothers with hepatoblastoma: implications for diagnosis and screening

Two brothers with hepatoblastoma were noted to have a family history of early onset colon cancer. Genetic testing of the younger brother revealed a deletion in exon 15 of the adenomatous polyposis coli (APC) gene (2710-2711delAG), consistent with a diagnosis of familial adenomatous polyposis (FAP). We review the clinical and molecular aspects of the relationship between hepatoblastoma and FAP, and the implications for diagnostic testing and cancer screening in affected patients.     

2003—2018年间中国女性宫颈癌发病与死亡趋势研究

  目的  研究2003—2018年中国20~79岁女性宫颈癌发病率和死亡率的变化趋势,对未来五年宫颈癌发病及死亡率的趋势进行预测。  方法  收集我国2003—2018年20~79岁女性宫颈癌的发病和死亡数据,利用联结点回归模型分析趋势变化规律,进一步利用年龄-时期-队列模型探讨年龄、时期和队列因素对宫颈癌发病和死亡率的影响。分别建立自回归滑动平均混合模型(autoregressive integrated moving average model, ARIMA)、灰色模型(grey model, GM)(1,1)和误逆差传播(back propagation, BP)神经网络模型对发病率和死亡率进行拟合,选取预测精度高的模型预测未来五年宫颈癌的发病率和死亡率。  结果  2003—2018年间女性宫颈癌的发病率具有2个转折点,发病趋势先快速上升随后下降;死亡率具有1个转折点,趋势是先下降再上升。总体上看,宫颈癌的发生风险随着年龄的增长而增大,在55~＜60岁达到峰值后缓慢下降。死亡风险从年龄上看不断上升,时期效应随着时期的推进而增大,队列效应则不断减弱。通过对比发现BP神经网络模型拟合的效果较好。  结论  2003—2018年间中国女性宫颈癌的发病率和死亡率整体上呈现下降的趋势,受年龄影响较大而受时期和队列的影响较小,未来五年发病率和死亡率将呈下降趋势。因此,应加强女性宫颈癌筛查和HPV疫苗接种工作,做好防控措施。     

2003—2016年上海市杨浦区阻塞性肺疾病死亡趋势分析

了解上海市宝山区户籍居民10年间慢性阻塞性肺疾病（COPD）的死亡率和潜在寿命损失年数（PYLL）的变化情况,为今后开展COPD防治工作提供策略和依据。

基于2010—2019年上海市宝山区居民死因监测系统,采用Excel 2010软件、SPSS 22.0软件和Joinpoint回归模型整理历年数据并综合分析,计算粗死亡率、标准化死亡率、年龄别死亡率、PYLL、年度变化百分比（APC）等指标。

2010—2019年间,上海市宝山区COPD年均粗死亡率为48.08/10万,标化后死亡率为39.95/10万,占同期总死亡人数的5.82%,位列宝山区死因顺位第3位。10年间,COPD男性粗死亡率、标化死亡率始终高于女性（P<0.01）。COPD粗死亡率和标化死亡率随年份增加均呈下降趋势（P<0.001）。COPD死亡率随年龄的增长呈现上升的趋势,其中≥75岁组的死亡占比最高,占全年龄段的85.71%。因COPD死亡所导致的PYLL总计为2 352.5年,其中男性为1 977.5年,女性为375.0年,COPD导致的每万人中的男性减寿年数（4.18年）远高于女性（0.82年）。

2010—2019年间上海市宝山区户籍居民COPD标化后死亡率呈明显下降趋势,但由于COPD患病带来的疾病负担重,尤其对老年、男性居民的健康危害影响深远,建议将COPD作为公共卫生服务中慢性病防制的重点疾病,并采取有效的干预防制措施。

     

肺癌患者血浆中APC基因启动子甲基化定量检测研究

背景与目的：APC基因编码的蛋白参与信号转导途径,大量研究证实APC启动子区的高甲基化在肿瘤的发生发展中起重要作用。本研究建立血浆APC基因实时荧光定量甲基化特异性基因扩增（methylation—specific PCR,MSP）检测方法,并对临床肺癌患者血浆进行检测,以确定该方法在肺癌诊断中的应用价值。方法：将APC基因启动子甲基化阳性肺癌细胞株NCI—H460细胞用有限稀释法获取单个集落形成的细胞,以经典的酚一氯仿法提取细胞DNA,并用MSP对APC基因甲基化进行验证,紫外分光光度计定量并以10倍稀释的浓度梯度依次投入到200μL健康人血浆中．得到模拟肺癌患者血浆,利用磁珠核酸提取方法从模拟肺癌及肺癌患者、肺部良性疾病患者和健康对照者血浆中提取DNA,对血浆DNA模板进行亚硫酸氢盐化学修饰;以模拟血浆样品作为标准品,采用外标准曲线法对各种血浆样品中APC甲基化进行定量分析。结果：所建立的实时荧光定量MSP检测方法的线性范围为1．5×10^2-1．5×10^5拷贝／mL。用该方法检测甲基化肿瘤细胞的DNA其最低检测限为1．5×10^2拷贝／mL。78例肺癌患者有40例组织中检测出APC基因甲基化阳性．其中的19例（47．5％）肺癌患者血浆中APC基因启动子甲基化阳性,APC甲基化浓度为1．67×10^2-6．78×10^3拷贝／mL,中位浓度为1．60×10^3拷贝／mL。38例组织阴性的肺癌患者、31例肺部良性疾病患者和23例健康者的血浆APC基因启动子甲基化均为阴性。结论：实时荧光定量MSP检测血浆APC基因甲基化在肺癌诊断方面具有潜在应用价值。     

Role of viral RNA and lipid in the adverse events associated with the 2010 Southern Hemisphere trivalent influenza vaccine

In Australia, during the 2010 Southern Hemisphere (SH) influenza season, there was an unexpected increase in post-marketing adverse event reports of febrile seizures (FS) in children under 5 years of age shortly after vaccination with the CSL 2010 SH trivalent influenza vaccine (CSL 2010 SH TIV) compared to previous CSL TIVs and other licensed 2010 SH TIVs. In an accompanying study, we described the contribution to these adverse events of the 2010 SH influenza strains as expressed in the CSL 2010 SH TIV using in vitro cytokine/chemokine secretion from whole blood cells and induction of NF-κB activation in HEK293 reporter cells. The aim of the present study was to identify the root cause components that elicited the elevated cytokine/chemokine and NF-κB signature. Our studies demonstrated that the pyrogenic signal was associated with a heat-labile, viral-derived component(s) in the CSL 2010 SH TIV. Further, it was found that viral lipid-mediated delivery of short, fragmented viral RNA was the key trigger for the increased cytokine/chemokine secretion and NF-κB activation. It is likely that the FS reported in children <5 years were due to a combination of the new influenza strains included in the 2010 SH TIV and the CSL standard method of manufacture preserving strain-specific viral components of the new influenza strains (particularly B/Brisbane/60/2008 and to a lesser extent H1N1 A/California/07/2009). These combined to heighten immune activation of innate immune cells, which in a small proportion of children <5 years of age is associated with the occurrence of FS. The data also demonstrates that CSL TIVs formulated with increased levels of splitting agent (TDOC) for the B/Brisbane/60/2008 strain can attenuate the pro-inflammatory signals in vitro, identifying a potential path forward for generating a CSL TIV indicated for use in children <5 years.     

Increased tissue factor pathway inhibitor activity is associated with myocardial infarction in young women: results from the RATIO study

Summary. Background: The tissue factor pathway inhibitor (TFPI)/protein S anticoagulant system is a potent inhibitor of blood coagulation. TFPI and protein S are major determinants of thrombin generation (TG) tests determined at low tissue factor (TF) and at high TF concentrations in the presence of activated protein C (APC). Both TFPI and protein S protect against venous thrombosis, but the importance of the TFPI/protein S system in arterial thrombosis remains unclear. Objectives: To investigate the influence of the TFPI/protein S anticoagulant system on the risk of myocardial infarction (MI) in young women. Methods: The RATIO study is a case–control study in women under 50 years of age, including 205 patients and 638 controls. TFPI and protein S were quantified using ELISA. The TFPI/protein S activity (nTFPIr) and the APC sensitivity ratio (nAPCsr) were determined using TG tests. Odds ratios (ORs) adjusted for putative confounders and corresponding 95% confidence intervals (95% CI) were determined. Results: Women with MI had higher TFPI levels than controls (135.9 ± 40% vs. 124.2 ± 41%), resulting in increased TFPI/protein S activities and increased APC sensitivity. Furthermore, an increased TFPI activity was associated with MI [nTFPIr: adjusted OR Q1 vs. Q4 = 2.1 (95%CI 1.1–4.1)]. Additionally, an increased APC sensitivity was associated with MI [nAPCsr: adjusted OR Q1 vs. Q4 = 1.7 (95% CI 0.9–3.2)] Conclusion: Women with MI had increased TFPI levels compared with controls. Consequently, the TFPI/protein S activity and APC sensitivity are increased in women with MI. Whether this increase in TFPI activity acts as a compensating mechanism for an increased procoagulant state or is a marker of endothelial damage remains to be investigated.     

Control of APC/C-dependent ubiquitin chain elongation by reversible phosphorylation

Most metazoan E3 ligases contain a signature RING domain that promotes the transfer of ubiquitin from the active site of E2 conjugating enzymes to lysine residues in substrates. Although these RING-E3s depend on E2 enzymes for catalysis, how they turn on their E2s at the right time and place remains poorly understood. Here we report a phosphorylation-dependent mechanism that ensures timely activation of the E2 Ube2S by its RING-E3, the anaphase-promoting complex (APC/C); while phosphorylation of a specific serine residue in the APC/C coactivator Cdc20 prevents delivery of Ube2S to the APC/C, removal of this mark by PP2A^B56 allows Ube2S to bind the APC/C and catalyze ubiquitin chain elongation. PP2A^B56 also stabilizes kinetochore–microtubule attachments to shut off the spindle checkpoint, suggesting that cells regulate the E2–E3 interplay to coordinate ubiquitination with critical events during cell division.By promoting the ubiquitination and proteasomal degradation of anaphase inhibitors, the anaphase-promoting complex (APC/C) triggers sister chromatid separation and mitotic exit (1–5). The APC/C also targets kinases and microtubule-binding proteins that ensure accurate assembly of the mitotic spindle. Misregulation of the APC/C has dramatic consequences for cell cycle control; whereas APC/C inhibition causes mitotic arrest and cell death, its untimely activation results in aneuploidy, a common feature of human cancer cells (6).As a RING-dependent E3 ligase, the APC/C stimulates the transfer of ubiquitin from the catalytic cysteine of E2 conjugating enzymes to lysine residues in substrates. In most cases, the APC/C initiates chain formation by using a specific E2, Ube2C (7–10). Once the first ubiquitin molecules have been attached to substrates, another conserved E2, Ube2S, extends K11-linked chains that are recognized by the proteasome for degradation (11–16). Ube2S frequently acts on short chains rather than on single ubiquitin subunits, thereby producing branched conjugates that impart high affinity for proteasomal receptors (13). Consistent with an important role in cell division, activation of Ube2S during mitosis results in a dramatic increase in the abundance of K11 linkages (17, 18), a chain topology required for APC/C-dependent substrate degradation (19).As with many key cell cycle regulators, the APC/C and Ube2S need to be under tight control, and overexpression of Ube2S can promote tumor growth and metastasis in mice (20). The correct timing of APC/C activation is ensured by the spindle checkpoint, a signaling cascade turned on by kinetochores that have not achieved bipolar attachment to the spindle (4, 21, 22). Spindle checkpoint signaling leads to formation of the mitotic checkpoint complex (MCC), composed of Mad2, BubR1, Bub3, and Cdc20. When bound to the APC/C, the MCC competes for recognition of substrate KEN boxes and puts the APC/C coactivator Cdc20 in a position where it is unable to engage another degron, the D box (23–25). In contrast, the MCC does not occupy the binding sites for APC/C E2s or impede the ability of the APC/C to stimulate ubiquitin transfer by Ube2S (12). Thus, although overexpression of Ube2S has been associated with tumorigenesis, the mechanisms that restrict its activity during mitosis have remained elusive.RING-E3s, such as the APC/C, engage their E2 enzymes in a dynamic manner (26). On binding a charged E2, the RING domain stabilizes a closed conformation between the E2 and its donor ubiquitin (14, 27–30). Once this ubiquitin is transferred to a target lysine, the E2 dissociates from the RING domain to allow for its recharging by the E1 (31). For most RING-E3s, the cycles of E2 engagement and dissociation are thought to occur constitutively (32), and only a few examples of controlled E2 activation are known. Access of Cdc34 to its specific RING-E3, the Skp1-Cul1-F box (SCF) complex, can be regulated by phosphorylation or competition with the inhibitory protein glomulin (33, 34). Reminiscent of this situation, Ube2S interacts with the APC/C in a cell cycle-dependent manner, and depletion of Cdc20 prevents Ube2S from stably binding to the APC/C in cells (12, 15). However, as part of the MCC, Cdc20 already associates with the APC/C during prometaphase, when APC/C activity must be low to allow sufficient time for chromosome alignment. How the ability of Ube2S to build ubiquitin chains is restricted during early stages of mitosis to safeguard cells against premature APC/C activation remains unknown.In this study, we identified a mechanism that establishes how the RING-E3 APC/C activates Ube2S at the right time and place. In early mitosis, phosphorylation of a specific serine residue in the APC/C coactivator Cdc20 prevents the stable association of Ube2S with Cdc20 and the APC/C. Conversely, removal of the inhibitory mark on Cdc20 by the phosphatase PP2A^B56 allows Ube2S to engage the APC/C and catalyze ubiquitin chain elongation. PP2A^B56 also stabilizes the kinetochore–microtubule interface to silence the spindle checkpoint (35, 36), suggesting that cells regulate the interplay between RING-E3s and their E2s to coordinate ubiquitination with important events in cell division.