CDC25B and CDC25C overexpression in nonmelanoma skin cancer suppresses cell death

Non‐melanoma skin cancer frequently results from chronic exposure to ultraviolet (UV) irradiation. UV‐induced DNA damage activates cell cycle arrest checkpoints through degradation of the cyclin‐dependent kinase activators, the cell division cycle 25 (CDC25) phosphatases. We previously reported increased CDC25A in nonmelanoma skin cancer, but CDC25B and CDC25C had not been previously examined. Consequently, we hypothesized that increased expression of CDC25B and CDC25C increases tumor cell proliferation and skin tumor growth. We found that CDC25B and CDC25C were increased in mouse and human skin cancers. CDC25B was primarily cytoplasmic in skin and skin tumors and was significantly increased in the squamous cell carcinoma (SCC), while CDC25C was mostly nuclear in the skin, with an increased cytoplasmic signal in the premalignant and malignant tumors. Surprisingly, forced expression of CDC25B or CDC25C in cultured SCC cells did not affect proliferation, but instead suppressed apoptosis, while CDC25C silencing increased apoptosis without impacting proliferation. Targeting CDC25C to the nucleus via mutation of its nuclear export sequence, however, increased proliferation in SCC cells. Overexpression of CDC25C in the nuclear compartment did not hinder the ability of CDC25C to suppress apoptosis, neither did mutation of sites necessary for its interaction with 14‐3‐3 proteins. Analysis of apoptotic signaling pathways revealed that CDC25C increased activating phosphorylation of Akt on Ser⁴⁷³, increased inhibitory phosphorylation of proapoptotic BAD on Ser¹³⁶, and increased the survival protein Survivin. Silencing of CDC25C significantly reduced Survivin levels. Taken together, these data suggest that increased expression of CDC25B or CDC25C are mechanisms by which skin cancers evade apoptotic cell death.     

SARS对疾病控制机构的影响研究

研究的目的是评估SARS对疾病控制机构的影响，为制定合理的补偿政策提供依据。方法：采用问卷调查的方法了解疾病控制机构工作量和经济活动的变化，使用比较分析的方法研究SARS产生的影响。结果：SARS发生以后，疾病预防控制机构的工作量下降，这些机构的支出增加，收支出现入不敷出的局面。结论：公共财政要给予疾病预防控制机构适当的补贴，SARS防治专项资金要足额及时到位。同时，要开发和落实有关卫生经济政策，保障卫生行业的可持续发展。     

疾控人员职业倦怠潜在剖面分析及与工作特征的关系

目的 通过对疾控(CDC)人员职业倦怠进行潜在剖面分析识别不同的职业倦怠类别,探讨工作特征各维度与职业倦怠类别间的独立效应。 方法 采用中文版职业倦怠量表(MBI-GS)、工作特征量表和自编一般资料调查表对943名疾控人员进行调查。使用潜在剖面分析方法识别疾控人员职业倦怠潜在类别,多分类Logistic回归分析探讨工作特征各维度与不同职业倦怠类别间的独立效应。 结果 疾控人员职业倦怠存在3种类别:低倦怠型(Ⅰ,54.7%)、高倦怠型(Ⅱ,24.1%)和成就感低落型(Ⅲ,21.2%)。高工作反馈、高工作意义是个体进入高倦怠型组的独立保护因素(OR=0.561;OR=0.612),高工作负荷、高工作对个体控制及情绪表达的要求是个体进入高倦怠型组的独立风险因素(OR=1.693;OR=1.770);高工作自主性是个体进入成就感低落型组的独立风险因素(OR=1.810),高工作对个体控制及情绪表达的要求是个体进入成就感低落型组的独立保护因素(OR=0.582)。 结论 疾控人员可区分出3种潜在职业倦怠类别,工作特征不同维度与潜在职业倦怠类别间存在独立效应。     

Effects of the CDC2 gene on adaptive mutation in the yeast Saccharomyces cerevisiae

We have studied the influence of a temperature-sensitive cdc2-1 mutation in DNA polymerase on the selection-induced mutation occurring at the LYS-2 locus in the yeast Saccharomyces cerevisiae. It was found that in cells plated on synthetic complete medium lacking only lysine, the numbers of Lys⁺ revertant colonies accumulated in a time-dependent manner in the absence of any detectable increase in cell number. When cdc2-1 mutant cells, after selective plating, were incubated at the restrictive temperature of 37°C for 5 h daily for 7 days, the frequency of an adaptive reversion of lys ^- Lys⁺ was significantly higher than the frequency in cells incubated only at the permissive temperature, or in wild-type cells incubated either at 23°C or 37°C. Therefore, when the proof-reading activity of DNA polymerase is impaired under restrictive conditions, the frequency of adaptive mutations is markedly enhanced.     

细胞周期蛋白E对乳腺癌细胞MCF-7生长及周期相关基因的影响

观察细胞周期蛋白（ｃｙｃｌｉｎ）Ｅ的表达对乳腺癌细胞ＭＣＦ－７生长及其他周期相关基因的影响。方法构建正义和反义ｃｙｃｌｉｎ Ｅ ｃＤＮＡ真核表达载体,并采用ｌｉｐｏｆｅｃｔ ＡＭＩＮＥ转染,将其导入ＭＣＦ－７细胞,获得稳定表达正义及反义ｃｙｃｌｉｎＥ的细胞系,经Ｓｏｕｔｈｅｒｎ和Ｗｅｓｔｅｒｎ ｂｌｏｔ检测有外源性片片段的插入及表达,并作细胞生长曲线、四甲偶氮唑盐（ＭＴＴ）法和流式细胞计数分析;用     

Induced recombination and reversion of theCDC8 gene in relation to the cell cycle of yeast

Summary The induction of mitotic recombination in theCDC8 locus was studied in a diploid strain heteroallelic forcdc8 mutations (cdc8-1/cdc8-3); mitotic reversion was studied in strainscdc8-1/cdc8-1 andcdc8-3/cdc8-3. Conversion and reversion did not occur in those cells blocked at the S stage of the cell cycle by exposure to a nonpermissive temperature. In stationary phase cells irradiated just prior to exposure to temperature stress, the induction of recombinants was rather low and the induction of revertants was minimal. Conversely, a significant induction ofcdc ⁺ occurred in logarithmic phase cells subjected to the same treatment. Irradiation of synchronously dividing cultures revealed that intragenic recombination occurs at all three stages of the cell cycle- G₁, S and G₂. It was also found that UV-induced gene reversion can occur during the S and G₂ stages, but not during the G₁ stage of the cell cycle.     

中国疾控中心近五年研究生就业情况分析

目的 基于近5年（2016—2020届）中国疾控中心培养的研究生毕业、就业情况进行分析和研究,为我国公共卫生人才培养提供数据支持。方法 利用北京高校毕业生就业平台及资源管理系统毕业生数据,分析研究生毕业、就业情况和特点。结果 2016—2020年累计毕业生共计687人,其中定向生119人,占17.3%,非定向生568人,占82.7%;非定向毕业生总体就业率为93.2%,其中2016—2018年的就业率比较稳定,均为100%;考研或继续从事博士后工作人数比较平稳,共55人,占9.7%;出国仅占0.4%。非定向毕业生就业去向疾控中心、卫生监督中心和妇幼保健院等专业公共卫生机构的最多,占53.5%;其次医院等医疗卫生机构（占18.1%）、企业（占9.3%）。就业去向选择专业公共卫生机构的近几年来保持平稳,选择医院等医疗卫生机构有略微增长趋势。结论 可通过提升公共卫生机构吸引力、加大教育培训等措施为我国公共卫生机构输送高质量公共卫生人才,推动我国卫生健康工作的发展。     

FROM THE EDITORS

Abstract

Consumer empowerment through authoritative health information is a positive force in today's health care environment. As the nation's lead agency for protecting the health and safety of people, the Centers for Disease Control and Prevention (CDC) has as part of its mission the responsibility of providing credible information to enhance health decisions. CDC health communications are provided through many venues, and particularly its Web site. This article identifies CDC consumer health sites, giving particular attention to two new initiatives, the CDC Kids Page and CDC en Espãol, which have been developed for specialized consumer health audiences.