紫杉醇生物合成相关酶类的研究进展

紫杉醇是红豆杉属植物次生代谢产物之一,是近20年来抗癌药物研究领域的重要发现。弄清楚紫杉醇合成途径和相关酶的反应可以从根本上大大提高紫杉醇的产量。综述近几年来紫杉醇生物合成途径中相关酶的研究工作,包括已经得到相应cDNA克隆的紫杉二烯合成酶,细胞色素P450氧化酶和3个紫杉烷的乙酰转移酶,由于GGPP是紫杉醇合成的必需前体,HMGR和GGPP合成酶的相关情况也有简述。     

内生真菌发酵生产紫杉醇的研究现状与展望

抗癌药物紫杉醇已在临床上广泛应用,但受原料红豆杉树木短缺的制约,存在巨大的供需差距,而内生真菌发酵生产紫杉醇是解决紫杉醇药源问题的很有前景的途径之一.结合课题组多年来开展的科学试验研究工作,概述了内生真菌发酵生产紫杉醇的优势、产紫杉醇内生真菌的分离研究现状和生物多样性及提高内生真菌生物合成紫杉醇量的途径.     

几种真菌诱导子对云南红豆杉细胞产生紫杉醇的影响

自１９９３年以来,紫杉醇（Ｔａｘｏｌ）已成为临床上治疗乳腺癌和卵巢癌的重要药物。由于其药源植物—红豆杉属植物（ＴａｘｕｓＬ．）生长非常缓慢,体内紫杉醇含量很低,且资源有限,所以人们一直在寻找解决紫杉醇药源短缺的方法。用红豆杉属植物组织培养技术生产紫杉醇被认为是一种有潜力的方法之一,受到人们的高度重视。虽然有关这方面的报道较多［１］,但该研究仍处在试验阶段,还未见用此方法商业化生产紫杉醇的报道。其重要原因是目前红豆杉属植物离体细胞的紫杉醇产量还比较低,而且不稳。人们仍在继续寻找提高紫杉醇产量的方法…     

紫杉醇构效关系研究进展

紫杉醇是近40年从红豆杉属植物中发现的最著名的天然抗肿瘤药物,在过去30年多年间紫杉醇因其独特的结构、新颖的作用机制和显著的抗癌活性成为化学家、药理学家和生物学家的研究热点.本文对紫杉醇构效关系的研究进行了总结,提供参考文献85篇.     

紫杉醇生物合成相关酶基因的克隆与表达

以牛儿基牛儿基二磷酸为前体的紫杉醇生物合成大约有20步酶促反应,其反应过程已基本阐明,近一半的相关酶基因已得到克隆与表达。综述了编码参与紫杉醇生物合成的紫杉二烯合酶、紫杉二烯5α羟化酶、紫杉烷10β羟化酶、紫杉烷13α羟化酶、紫杉二烯5α醇O乙酰基转移酶、紫杉烷2α苯甲酰转移酶、去乙酰基巴卡亭Ⅲ10βO乙酰转移酶、3氨基3苯基丙酰转移酶和3N去苯甲酰2脱氧紫杉醇苯甲酰转移酶等9个酶基因的克隆和表达方面的研究情况,并指出随着紫杉醇生物合成的分子生物学研究的不断深入,利用分子生物技术大规模生产紫杉醇将为期不远 。     

产紫杉醇植物内生真菌的研究进展

紫杉醇是一种二萜类生物碱,通过抑制微管解聚和稳定微管的作用来抑制有丝分裂,是一种高效、低毒、广谱的天然抗癌药物,已在临床上广泛使用,市场需求量巨大,但由于生产原料的制约,价格十分昂贵。近年来的研究表明,利用植物内生真菌发酵生产紫杉醇是解决药源问题的有效途径。本文就产紫杉醇内生真菌的分离与鉴定方法、紫杉醇的提取与检测技术及在研的菌种进行综述,并进一步提出目前内生真菌源紫杉醇研究存在的问题与前景。     

紫杉醇生物合成途径中相关酶的研究进展

抗癌新药紫杉醇是具有萜类环状结构的一种重要次生代谢产物 ,研究紫杉醇的生物合成对于通过基因工程手段提高紫杉醇的产量 ,解决目前资源紧缺造成的巨大供求矛盾具有重要意义 ,这就需要对紫杉醇生物合成途径中催化各步反应 (尤其是关键步骤 )的酶以及编码这些酶的基因有个全面的了解。对近年来紫杉醇生物合成途径中相关酶的研究进行了综述 ,大部分酶及相关基因已被分离、克隆 ,但还有一些酶及相关基因没有发现 ,有待继续深入研究。     

内生真菌紫杉醇生物合成的研究现状与展望

紫杉醇是重要的抗癌药物之一,已经证明其对多种癌症具有显著疗效。目前,人们主要是从红豆杉的树皮中提取、分离和纯化紫杉醇,但由于红豆杉为生长缓慢、散生、濒危的珍稀植物,且随着紫杉醇临床用途的不断拓宽,市场需求的稳定增长,单纯依靠从红豆杉树皮中提取紫杉醇已经无法满足日益增长的市场需求。为了解决紫杉醇的药源不足,科学家已把目光从红豆杉树分离提取紫杉醇转向了其他替代方法,如化学全合成、半合成、组织培养与细胞培养、微生物发酵法生产紫杉醇等。因此,了解内生真菌紫杉醇生物合成的分子基础和遗传调控机制,对解析内生真菌紫杉醇生物合成机制、构建高产紫杉醇基因工程菌株和早日实现内生真菌紫杉醇工业化生产具有重要的科学意义和现实意义。结合本课题组多年来的科研工作,概述了红豆杉细胞紫杉醇生物合成途径、内生真菌发酵生产紫杉醇的优势、产紫杉醇内生菌的分离研究现状和生物多样性及紫杉醇生物合成相关基因的研究现状。内生真菌生物发酵合成紫杉醇是可以无限生产、大量获取紫杉醇、解决紫杉醇药源短缺问题的很有前景的方法之一。     

诱导子对红豆杉培养细胞紫杉醇产量的影响

利用红豆杉细胞培养技术生产紫杉醇是目前紫杉醇生产的研究热点之一,并已取得了较大进展,其中如何提高紫杉醇的产量是研究的关键。目前通过促进紫杉醇代谢来提高产量最常用、最重要的方法之一是添加诱导子。这是来源于病原微生物的一类化学物质,具有诱导植物细胞中防卫基因表达诱发植物过敏反应和促进植物细胞中特定次生代谢产物的合成等多种功能。就近年来在红豆杉细胞培养生产紫杉醇方面的研究进展进行简要论述,着重介绍了添加诱导子在促进紫杉醇生物合成中的应用。     

对几种天然药物的开发建议

最近我们对美国、加拿大和印度的天然药物研究与开发进行了考察,有以下建议: 1 紫杉醇(Taxol):美国农业部1961年对太平洋紫杉进行采样筛选,1964年证实该植物有抗癌活性,1971年M.E.Wall发表紫杉醇结构及抗癌活性,1977年美国国家癌症研究所(NCI)证实Taxol有独特抗癌机理,1992年美国FDA批准用于治卵巢癌。前后达30年,目前进行的乳腺癌和肺癌临床亦可望成功。据此,可以认为Taxol是近20年来天然抗癌药的重大发现。现在的情况是Bristol-Myers Squibb药厂(BMS)拥有美国专卖权五年(Taxol无专利),已积累Taxol超过100kg,美国每年有12000妇女死于卵巢癌,年需20-25kg(每病人需1.2gm至3gm),     

Age trends in pre‐cancerous and cancerous lesions of the uterine cervix in a cytology screening programme: what should be the target age group for a major thrust of screening in resource‐limited settings?

Objective:  To identify the target age group where screening efforts may be concentrated in order to reduce the incidence of cervical cancer in resource-limited countries.
Study design:  The results of cyto-screening in a hospital-based screening programme for early detection of cervical cancer were analysed retrospectively. The frequency of epithelial cell abnormalities (ECAs) was computed in different age groups.
Observations and results:  A total of 5.6% ECAs were detected on cyto-screening. The peak age incidence for squamous intraepithelial lesions (SILs) was in the 30–39 age group while that for malignancies was age >60 years. The mean ages for LSIL, HSIL and cancer were 34.7, 37.7 and 51.8 years respectively. Around 43% LSILs and 48% HSILs presented in the fourth decade. If both fourth and fifth decade are covered by screening we could detect almost two-thirds of SILs.
Conclusions:  A distinct latent period of more than a decade between the onset of SIL and development of frank cancer provides us with ample opportunity to prevent cervical cancer through screening. Our data validate the WHO recommendation of once in a lifetime screening of women in their fourth decade, for low-resource settings. If resources permit, screening can be extended to include women in the fifth decade. This approach would enable us to pick up maximum SILs within the available resources and prevent their progression to cancer.     

Trends in disability-adjusted life years of lung cancer among women from 2004 to 2030 in Guangzhou,China: A population-based study

BackgroundForecast of disease burden in lung cancer is an important health agenda. One of the main challenges is to predict the evolution of trends in disability-adjusted life year (DALY) of lung cancer so as to anticipate the future burden and to coordinate the supply of sufficient health services and care.MethodsUsing 2004–2013 cancer registry data in Guangzhou, we fitted Bayesian age-period-cohort models with age, period, and cohort effects to analyze trends of lung cancer among women, and then made forecast for DALY of lung cancer until 2030.ResultsDuring 2004–2013, there was an annual average of 10,582 DALYs for lung cancer (15.84% of total DALY). In 2014–2030, DALY is expected to reach 234,752 person-years for lung cancer (12.25% of total DALY), with an annual mean of 13,809 DALYs. Lung cancer crude DALY rate is projected to rise steadily from 257.56 (95% uncertainty interval: 165.97–361.22) in 2014 to 316.99 (219.96–419.41) per 100,000 women in 2030, and the rise is mainly seen in 45–64 years age group. Lung cancer DALY rate remains the highest in the 65–89 years age group.ConclusionsWomen at 65–89 years carry the highest lung cancer burden among other age groups in Guangzhou. The DALY rate of lung cancer is projected to increase most precipitously for the 45–64 years age group. This indicates that concerted efforts are needed to develop adequate cancer services, and to reassess health resources for control and care of lung cancer in these populations.     

Demands on surgical inpatient services after mass mammographic screening.

The changes in the demand for surgical inpatient care created by mammographic screening for breast cancer were analysed by comparing two counties, one with and one without a mass screening campaign. A comprehensive computerised register of inpatient care in the region was used. The results indicate that population based screening offered to women above 40 years and repeated every two to three years will increase the number of operations required for breast cancer and inpatient days by at least 150% during the initial screening round. During the second round the figures tend to return to previous levels. Of decisive importance for the demands on health service resources are the specificity of screening, the duration of the first screening round, and the age groups included.     

Uptake of Colorectal Cancer Screening among Ontarians with Intellectual and Developmental Disabilities

Under-screening for cancer may contribute to a greater disease burden in individuals with intellectual and developmental disabilities (IDD) as their life expectancy increases. In 2008, the province of Ontario launched Canada’s first population-based colorectal cancer screening program. Our objectives were to compare the proportions of Ontarians with and without IDD who have undergone colorectal cancer screening and to examine factors associated with screening uptake among Ontarians with IDD. Records for Ontario residents 50–64 years of age were linked across various administrative health and social services datasets to identify individuals with IDD and to select a random sample of the age-equivalent Ontario population without IDD as a comparison group. Logistic regression models were fit to examine the odds of screening uptake among individuals with IDD while controlling for age, sex, urban or rural residence, neighbourhood income quintile, expected use of health care resources, and being enrolled with or seeing a physician in a patient enrolment model (any of several primary care practice models designed to improve patient access and quality of care in Ontario), and to examine the association between these variables and colorectal cancer screening in the IDD population. The odds of having had a fecal occult blood test in the previous two years and being up-to-date with colorectal tests were 32% and 46% lower, respectively, for Ontarians with IDD compared to those without IDD. Being older, female, having a greater expected use of health care resources, and being enrolled with or seeing a physician in a primary care patient enrolment model were all significantly associated with higher odds of having been screened for colorectal cancer in the IDD population. These findings underscore the need for targeted interventions aimed at making colorectal cancer screening more equitable.     

Present state and possibilities for improvement of cancer prevention and early detection in the Osijek-Baranya county

Cancer morbidity and mortality are on a steady increase in Croatia. Technologic possibilities for appropriate management are available for four cancer sites, i.e. cancer of the breast, cervix uteri, colorectum and prostate, and include cancer prevention and early detection in individuals yet free from manifest signs of the disease. The magnitude of the problem, the experience acquired to date, health care personnel available, and additional resources required to launch a systematic program of early detection of the disease are presented. The program should be initially launched in a county with greatest experience in early detection of cancer, where health care service is ready to immediately start its implementation. The role of family physician, gynecologic service at primary health care level, and polyclinic-consultation hospital service in program implementation is described. The following three possible options for early detection of cancer are analyzed and proposed: minimal program (early detection every 3 years), medium program (the same individuals examined every 2 years), and optimal program proposed by the American Cancer Society and other national and international organizations.     

Databases and Web Tools for Cancer Genomics Study

Publicly-accessible resources have promoted the advance of scientific discovery. The era of genomics and big data has brought the need for collaboration and data sharing in order to make effective use of this new knowledge. Here, we describe the web resources for cancer genomics research and rate them on the basis of the diversity of cancer types, sample size, omics data comprehensiveness, and user experience. The resources reviewed include data repository and analysis tools; and we hope such introduction will promote the awareness and facilitate the usage of these resources in the cancer research community.     

Treatment of the terminal stages of breast cancer.

To assess the intensity of and changes in diagnostic investigations and treatment in the terminal stages of breast cancer 555 patients in the area of Tampere University Central Hospital in whom breast cancer had been diagnosed from 1977 to 1980 were followed up for five years. The case notes for the last visit of 519 patients were analysed. The amount of diagnostic activity was similar for those who died and for the survivors. A higher proportion of women who died than of women who survived received treatment at the last follow up visit, and 2.6 times as many of those dying within one week of the last visit were given chemotherapy as were survivors with recurrent disease. Resources devoted to diagnostic investigations and treatment of cancer in terminally ill patients could be better used for care of the patients. This would be more likely to improve the patients'' quality of life and conserve resources.     

放线菌次级代谢产物研究进展

随着耐药细菌和新型病毒的不断出现，癌症的发病率和死亡率持续上升，迫使人们不断寻找新的化合物来治疗疾病。放线菌次级代谢产物结构新颖，作用独特，具有抗菌、杀虫、抗肿瘤、免疫抑制等活性，广泛应用于医疗、农业、食品等领域，深入挖掘放线菌资源来开发新型抗生素潜力巨大。然而从自然界分离的放线菌生产目标化合物的能力较弱，这直接影响其工业应用，增加其生产成本，因此构建目标化合物高产菌株显得尤为重要。本文以此为出发点，从放线菌新药资源挖掘和放线菌产抗能力提高两个方面对近年来的研究情况进行概述，为放线菌资源开发提供参考。     

利用人工智能预测癌症的易感性、复发性和生存期

癌症具有较高的发病率和致死率,对人类健康具有重大威胁。癌症预后分析可以有效避免过度治疗及医疗资源的浪费,为医务人员及家属进行医疗决策提供科学依据,已成为癌症研究的必要条件。随着近年来人工智能技术的迅速发展,对癌症患者的预后情况进行自动化分析成为可能。此外,随着医疗信息化的发展,智慧医疗的理念受到广泛关注。癌症患者作为智慧医疗的重要组成部分,对其进行有效的智能预后分析十分必要。本文综述现有基于机器学习的癌症预后方法。首先,对机器学习与癌症预后进行概述,介绍癌症预后及相关的机器学习方法,分析机器学习在癌症预后中的应用;然后,对基于机器学习的癌症预后方法进行归纳,包括癌症易感性预测、癌症复发性预测、癌症生存期预测,梳理了它们的研究现状、涉及到的癌症类型与数据集、用到的机器学习方法及预后性能、特点、优势与不足;最后,对癌症预后方法进行总结与展望。     

Cost-Effectiveness of Breast Cancer Control Strategies in Central America: The Cases of Costa Rica and Mexico

This paper reports the most cost-effective policy options to support and improve breast cancer control in Costa Rica and Mexico. Total costs and effects of breast cancer interventions were estimated using the health care perspective and WHO-CHOICE methodology. Effects were measured in disability-adjusted life years (DALYs) averted. Costs were assessed in 2009 United States Dollars (US$). To the extent available, analyses were based on locally obtained data. In Costa Rica, the current strategy of treating breast cancer in stages I to IV at a 80% coverage level seems to be the most cost-effective with an incremental cost-effectiveness ratio (ICER) of US$4,739 per DALY averted. At a coverage level of 95%, biennial clinical breast examination (CBE) screening could improve Costa Rica''s population health twofold, and can still be considered very cost-effective (ICER US$5,964/DALY). For Mexico, our results indicate that at 95% coverage a mass-media awareness raising program (MAR) could be the most cost-effective (ICER US$5,021/DALY). If more resources are available in Mexico, biennial mammography screening for women 50–70 yrs (ICER US$12,718/DALY), adding trastuzumab (ICER US$13,994/DALY) or screening women 40–70 yrs biennially plus trastuzumab (ICER US$17,115/DALY) are less cost-effective options. We recommend both Costa Rica and Mexico to engage in MAR, CBE or mammography screening programs, depending on their budget. The results of this study should be interpreted with caution however, as the evidence on the intervention effectiveness is uncertain. Also, these programs require several organizational, budgetary and human resources, and the accessibility of breast cancer diagnostic, referral, treatment and palliative care facilities should be improved simultaneously. A gradual implementation of early detection programs should give the respective Ministries of Health the time to negotiate the required budget, train the required human resources and understand possible socioeconomic barriers.