不饱和脂酸及其硒化物对BEL-7402人肝癌细胞的杀伤作用及DNA合成的影响

研究了亚麻酸、亚油酸、油酸及其硒化物对人肝癌细胞杀伤作用及对ＤＮＡ合成的影响。结果表明，三种脂酸及其硒化物对ＢＥＬ－７４０２人肝癌细胞均有杀伤作用，其中以硒化亚麻酸杀伤作用最强，５００μｇ／ｍｌ即可杀灭全部肝癌细胞，且具剂量效应关系。其次是亚麻酸、亚油酸和硒化亚油酸。油酸和硒化油酸杀伤作用较弱。１５０μｇ／ｍｌ的亚麻酸、亚油酸及其硒化物和硒化油酸对肝癌细胞的ＤＮＡ合成均有明显抑制作用（Ｐ＜０．０１），其中以硒化亚麻酸抑制作用最强（Ｐ＜０．０５～０．０１），且具有剂量效应关系。亚麻酸、亚油酸对ＤＮＡ合成的抑制作用与相应的硒化物之间无明显差异（Ｐ＞０．０５），而只含一个双键的油酸对ＤＮＡ合成无明显抑制作用，其硒化物则有显著抑制作用，两者的差异非常显著（Ｐ＜０．０１）。     

miR-203对Tca8113增殖能力影响观察

目的：探讨miR-203对人舌鳞癌细胞系Tea8113增殖能力的影响。方法：通过慢病毒转染技术构建miR-203过表达的舌鳞癌细胞模型。RT—PCR法检测miR-203过表达慢病毒转染前后miR-203的表达水平；MTT方法检测miR-203过表达（microup组）及阴性对照（NC组）2组细胞的增殖能力，连续检测5d，酶标仪检测A490值，绘制细胞增殖曲线；PI—FACS细胞周期检测miR-203过表达后对DNA合成和细胞周期的影响，取处于对数生长期的细胞，70％乙醇固定〉1h，细胞染色，流式细胞仪检测。结果：成功建立了miR-203过表达舌鳞癌细胞模型。定量PCR结果显示，Tca8113细胞中，microup组miR-203表达丰度是NC组的286．262倍，t=34．879，P=0．001。MTT检测结果表明，与Nc组相比，microup组细胞增殖能力明显降低；检测第4天microup组A490值为0．492±0．011，NC组为0．681±0．009，t=23．463，P〈0．001。PI-FACS细胞周期检测结果显示，microup组DNA合成前期（G1期）细胞所占百分率为（58．98±0．56）％，较NC组的（53．86±O．96）％明显增高，t=-7．989，P=0．001；而DNA合成期（S期）、合成后期（G。期）及有丝分裂期（M期）细胞所占百分率降低。结论：miR-203可能通过将细胞周期阻滞于G1期，从而抑制舌鳞癌细胞系Tca8113的细胞增殖能力。     

T7体外转录siRNA靶向干扰Pim-2效应观察

[目的]观察T7RNA聚合酶介导体外转录合成siRNA靶向干扰Pim-2基因表达的效应。[方法]利用T7RNA聚合酶介导的体外转录合成靶向Pim-2的siRNAⅠ、Ⅱ、Ⅲ．将其转染入人结肠癌细胞株SW480。利用RT-PCR和Western blot观察Pim-2基因在RNA和蛋白质水平的表达变化。[结果]与对照细胞相比，转染siRNAⅠ、Ⅱ、Ⅲ48h后，Pim-2基因mRNA的抑制率分别为65.4％（P〈0．05），46．2％（P〈0．05）和56．1％（P〈0．05）；转染72h后，Pim-2基闵蛋白表达抑制率分别为61．6％（P〈0．05），45．8％（P〈0．05）和55．6％（P〈0．05）。[结论]T7体外转录合成siRNA，能有效而特异地抑制人原癌基因Pim-2的表达．     

增殖细胞核抗原及其在卵巢肿瘤中表达的意义

增殖细胞核抗原（ProliferatingCellun－clear－antigen，PCNA）又称周期素，由Miyachi等在1978年发现提纯［1］。主要分布在增殖细胞、促有丝分裂剂刺激转化的淋巴细胞，以及实体肿瘤中有增殖能力的细胞。PCNA是DNA多聚酶a的辅助蛋白，是DNA合成必不可少的因子，同时也是一种细胞周期调控蛋白。它的表达和合成与细胞增殖活性密切相关，已开始用于肿瘤动力学研究［2～10］。一、增殖细胞核抗原（PCNA）1．PCNA的一般性质PCNA是一种酸性核蛋白，含有261个氨基酸，其中酸性氨基酸数目明显多于碱性氨基酸数目，等电点PI＝4．8，分…     

内皮素在培养的肝癌细胞中的表达及其作用

 目的：确定人肝癌细胞合成释放内皮素（ET）与否；探讨外源性ET-1对培养的人肝癌细胞增殖的影响。方法：应用特异性放射免疫分析法测定肝癌细胞（HCC9204和SMMC7721）培养液中ET-1含量；采用3H-胸腺嘧啶核苷（3H－TdR）掺入和液体闪烁技术观察ET－1（10^－11～10^－7mol／L）对培养的加或不加表皮生长因子（EGF）的肝癌细胞增殖的影响。结果：培养的肝癌细胞HCC9204和SMMC7721均能分泌ET－1，并呈时间依赖性。培养24h为分泌高峰期，HCC9204和SMMC7721在有血清条件下ET-1浓度分别为86．38±7．7Pg／ml，76．32±8．4pg／ml，均显著高于各自无血清组（28．16±3．34pg／ml，23．22±4．72pg／ml）（P＜0．01）。ET－1单独作用对肝癌细胞DNA合成没有影响（P＜0．05）；在EGF（1nmol／L）存在时，ET－1在10^－11～10^－17mol／L时DNA合成增殖率为27．4％～86．6％（P＜0．05），且呈剂量依赖性（γ=0．7531，P＜0．05）。结论：人肝癌细胞可合成并分泌ET；ET－1单独作用对肝癌细胞DNA合成没有影响，但能明显增强EGF对肝癌细胞的增殖作用。     

抗肿瘤药物的研究进展

抗肿瘤药物的研究进展潘启超主题词抗肿瘤药／药理学抗肿瘤药／治疗应用中图号Ｒ９７９．１近年来，抗肿瘤药物的发展突飞猛进，发展的药物种类很多，现概括说明各类药的发展。１干扰ＤＮＡ前体合成及多胺合成的药物１．１干扰叶酸代谢药物〔１〕自４０年代甲氨蝶呤（ＭＴ...     

苯并（a）芘对人血淋巴细胞的遗传损伤作用研究Ⅱ、苯并（a）芘DNA损伤作用研究

本研究第2部分，应用DNA共价结合试验．非程序DNA合成(UDS)试验、DNA解螺旋荧光分析(FADU)试验和DNA复制合成抑制(DRSI)试验，综合检测了苯并(a)芘(BaP)对人血淋巴细胞的DNA损伤作用．人血淋巴细胞来源和分离方法，UDS，FADU、DRSI试验的细胞染毒浓度和条件均与本研究第1部分相同．     

氯化镉对SHE细胞的恶性转化作用及转化细胞~3H－TdR掺入的研究

本研究用０．２～１．６μｍｏｌ／Ｌ的氯化镉溶液处理原代培养的叙利亚地鼠胚胎细胞（ＳＨＥ），同时选择三蒸水和亚硝基胍ＭＮＮＧ作为阴性和阳性对照。结果表明：实验剂量范围内各组ＳＨＥ细胞均出现转化集落，并且有剂量—反应关系，氯化镉具有较强的致癌能力。为了进一步研究转化细胞的ＤＮＡ合成情况，我们又进行了３Ｈ－ＴｄＲ掺入研究。结果显示：转化细胞３Ｈ－ＴｄＲ的掺入量约为阴性对照组的１．７～３．０倍，但又略低于Ｌ９２９肿瘤细胞株３Ｈ－ＴｄＲ掺入量（约为阴性对照组４．４倍），从而说明转化细胞ＤＮＡ合成非常旺盛，氯化镉具有引起ＳＨＥ细胞恶性转化的能力，它可能是一种潜在的致癌剂。     

肿瘤坏死因子对恶性肿瘤蛋白质代谢和细胞周期动力学的影响

Ｓｐｒａｇｕｅ－Ｄａｗｌｅｙ大鼠皮下接种Ｗａｌｋｅｒ２５６癌肉瘤细胞后，连续３天腹腔内注射重组人肿瘤坏死因子－α（ＴＮＦ）之后，分别切取肿瘤进行细胞周期动力学测定和蛋白质代谢分析。结果表明，ＴＮＦ治疗组肿瘤体积和重量显著减少，肿瘤蛋白分段合成率（２５．３％±３．５％·ｄ－１，对照组４２．９％±２．７％·ｄ－１，ｐ＜０．０１）、蛋白合成率（０．２０±０．０５ｇ·ｄ－１，对照组１．１４±０．２０ｇ·ｄ－１，Ｐ＜０．００１）和分段生长率（２４．３％±２．１％·ｄ－１，对照组３５．８％±２．３％·ｄ－１，Ｐ＜０．０１）均显著降低，肿瘤蛋白分段降解率则无明显改变。流式细胞仪测定表明，ＴＮＦ治疗组在５’－溴脱氧尿苷注射６小时后，肿瘤细胞标记指数（３０．８％±４．２％，对照组４４．７％±４．２％，Ｐ＜０．０１）和Ｇ１期增长率（６．０％±１３％，对照组１２．２％±２．５％，Ｐ＜０．０１）均显著减少，相对移动率无明显改变。研究结果提示，ＴＮＦ在荷瘤大鼠中抗肿瘤作用的代谢机理，在于减少肿瘤细胞ＤＮＡ和肿瘤蛋白质的合成，从而抑制肿瘤的生长。     

硒化亚油酸及硒化亚麻酸对肿瘤细胞DNA合成的影响

本文报道用氚一胸腺嘧啶核苷（＾３Ｈ－ＴｄＲ）掺入法研究了新型抗癌药－硒化亚油酸及硒化亚麻酸对小鼠Ｓ１８０细胞ＤＮＡ合成的影响。结果表明，这两种新型抗肿瘤药物能明显抑制＾３Ｈ－ＴｄＲ掺入肿瘤细胞，在１００μｇ／ｍｌ的浓度下，它们对Ｓ１８０瘤细胞ＤＮＡ合成的抑制率分别达到８９．０％和８８．３％，这些结果表明硒化亚油酸及硒化亚麻酸的抗癌机理之一是它们对＾３Ｈ－ＴｄＲ掺入肿瘤细胞的干扰。     

Neural invasion induces cachexia via astrocytic activation of neural route in pancreatic cancer

Pancreatic cancer is characterized by a high frequency of cachexia, pain and neural invasion (N-inv). Neural damage is occurred by N-inv and modulates pain and muscle atrophy via the activation of astrocyte in the connected spine. The activated astrocyte by N-inv, thus, may affect cachexia in pancreatic cancer. Clinical studies in patients and autopsy cases with pancreatic cancer have revealed that N-inv is related to cachexia and astrocytic activation. We established a novel murine model of cancer cachexia using N-inv of human pancreatic cancer cells. Mice with N-inv showed a loss of body weight, skeletal muscle and fat mass without appetite loss, which are compatible with an animal model of cancer cachexia. Activation of astrocytes in the spinal cord connected with N-inv was observed in our model. Experimental cachexia was suppressed by disrupting neural routes or inhibiting the activation of astrocytes. These data provide the first evidence that N-inv induces cachexia via astrocytic activation of neural route in pancreatic cancer.     

Multitargeted treatment of cancer cachexia

Cancer cachexia is defined as a multifactorial syndrome characterized by an ongoing loss of skeletal muscle mass (with or without loss of fat mass) that cannot be fully reversed by conventional nutritional support and leads to progressive functional impairment. The prominent clinical feature of cachexia is weight loss in adults. Anorexia, inflammation, insulin resistance, and increased muscle protein breakdown frequently are associated with cachexia. One single therapy may not be completely successful in the treatment of cachexia because of the complexity of the pathogenesis and symptoms of the cachexia syndrome. Among effective treatments, progestogens currently are considered the best available treatment option and are the only approved drugs in Europe for the treatment of cancer- and AIDS-related cachexia. However, they have limited efficacy in treating cancer cachexia. However, thalidomide, selective COX-2 inhibitors, ghrelin mimetics, and selective androgen receptor modulators showed promising results but should be defined further and confirmed in clinical trials. Therefore, to date, despite several years of coordinated efforts in basic and clinical research, the practice guidelines for the prevention and treatment of cancer-related anorexia cachexia syndrome (CACS) are lacking. The management of CACS is a complex challenge that should address the different causes underlying this clinical event. Recent studies showed that integrated, multitargeted approaches are more effective than single-agent approaches for the treatment of CACS. Further clinical trials to improve and refine current strategies to counteract cancer cachexia using multimodal interventions, including nutritional supplementation, anabolic agents, and antiinflammatory drugs along with an appropriate physical exercise program, are warranted.     

Report of a Joint Cancer Research UK/Medical Research Council workshop on cancer cachexia research at the Royal College of Physicians, Tuesday, 2 December 2003

A joint workshop held by Cancer Research UK and the Medical Research Council aimed to stimulate interest in further research into the area of cancer cachexia. The workshop was divided into four sessions: an overview of cancer cachexia, potential mechanisms involved and methodologies that might be used to understand cachexia, and also the experience of cachexia from other disease areas. The workshop identified a need to develop a multimodal therapeutic approach to cancer cachexia and a need to undertake more multidisciplinary research.     

The rationale forpreventing cancer cachexia：targeting excessive fatty acid oxidation

Cachexia commonly occurs at the terminal stage of cancer and has largely unclear molecular mechanisms. A recent study published inNature Medicine, entitled “Excessive fatty acid oxidation induces muscle atrophy in cancer cachexia,”reveals that cachectic cancer cells can secrete multiple cytokines that induce excessive fatty acid oxidation, which is responsible for muscle loss in cancer cachexia. Inhibition of fatty acid oxidation using etomoxir can increase muscle mass and body weight in cancer cachexia animal models. The usage of stable cachexia animal models is also dis?cussed in this research highlight.     

癌性恶病质发病机制的研究进展

目的:总结癌性恶病质发病机制及实验研究现状,探讨厌食、机体代谢异常、细胞因子在恶病质发生中的作用机制,整理恶病质基础实验研究进展。方法:应用PubMed及CNKI期刊全文数据库检索系统,以"恶病质"、"发病机制"和"实验研究"等为主题词,检索2005-2011年的相关文献,共检索到61篇文献。纳入标准:1)恶病质的发病机制研究;2)厌食、机体代谢异常、细胞因子在恶病质发生中的作用;3)有关恶病质的基础实验研究。根据纳入标准符合分析的文献有29篇。结果:恶病质是晚期癌症患者死亡的重要原因。厌食、机体代谢异常、细胞因子变化促使了恶病质的发生,许多学者通过基础实验研究了恶病质动物模型及药物干预作用,并取得了良好效果。结论:恶病质发病机制较为复杂,有待进一步深入系统研究。药物干预尤其是中医中药的治疗,是防治恶病质的一个重要措施。     

Adipose tissue lipolysis and energy metabolism in early cancer cachexia in mice

Cancer cachexia is a progressive metabolic disorder that results in depletion of adipose tissue and skeletal muscle. A growing body of literature suggests that maintaining adipose tissue mass in cachexia may improve quality-of-life and survival outcomes. Studies of lipid metabolism in cachexia, however, have generally focused on later stages of the disorder when severe loss of adipose tissue has already occurred. Here, we investigated lipid metabolism in adipose, liver and muscle tissues during early stage cachexia – before severe fat loss – in the colon-26 murine model of cachexia. White adipose tissue mass in cachectic mice was moderately reduced (34–42%) and weight loss was less than 10% of initial body weight in this study of early cachexia. In white adipose depots of cachectic mice, we found evidence of enhanced protein kinase A - activated lipolysis which coincided with elevated total energy expenditure and increased expression of markers of brown (but not white) adipose tissue thermogenesis and the acute phase response. Total lipids in liver and muscle were unchanged in early cachexia while markers of fatty oxidation were increased. Many of these initial metabolic responses contrast with reports of lipid metabolism in later stages of cachexia. Our observations suggest intervention studies to preserve fat mass in cachexia should be tailored to the stage of cachexia. Our observations also highlight a need for studies that delineate the contribution of cachexia stage and animal model to altered lipid metabolism in cancer cachexia and identify those that most closely mimic the human condition.     

中药调节肠道菌群改善肿瘤恶液质作用的研究进展

肠道菌群与肿瘤相关性的研究目前仍是临床上一个值得期待的研究热点。肠道菌群失调与肿瘤恶液质的发生发展有着重大的联系。运用中药调节肠道菌群可以作为肿瘤放化疗后的辅助治疗，对机体的免疫调节起着很重要的作用，而肿瘤恶液质的发生与发展一定程度上会受到肠道菌群的影响，在肿瘤恶液质的防治中肠道菌群也起到了重要作用。从另一方面来讲，肿瘤恶液质的发生也会造成机体肠道菌群的失调，对于这种情况，用中药来对肠道菌群失调来进行调节，在一定程度上对肿瘤恶液质起到改善作用，通过中药调节肠道菌群对肿瘤恶液质的影响来探索中药、肠道菌群失调以及肿瘤恶液质三者之间的关系是本文所要阐述的，目的是促进祖国医学在肿瘤治疗方面发挥更大的效用，充分发挥中医的特色优势，尽早攻克肿瘤这个医学难题。     

Molecular analysis of xenograft models of human cancer cachexia--possibilities for therapeutic intervention

Approximately 50% of all cancer patients develop cachexia, a paraneoplastic syndrome that is characterized by wasting of adipose tissue and skeletal muscle mass. Cytokines, including TNF-alpha, interleukins-1, -6, and interferon-A are known mediators of the cachectic process. The latter however represent only one of many imbalanced systems in cancer cachexia. The aim of this study was to further delineate the pathogenesis of cachexia by molecular profiling. Human renal cancer xenografts that do and do not induce cachexia in mice were used as disease models. Cachexia-associated gene expression was studied on Human Genome U95 Affymetrix arrays and revealed several new genes such as TNF-alpha ligand superfamily protein, interferon-A treatment inducible protein, and DKFZ5641I1922. The expression of the IL-8 gene was also elevated in cachexia inducing xenografts (CIX). At the protein level, TNF-alpha was found expressed only in CIX, whereas IL-1 and IL-6 were not cachexia specific. Levels of parathyroid hormone-related protein were elevated in CIX and accompanied by hypercalcemia. COX-2 and prostaglandin E2 were also found to be over expressed. By using the COX-2 inhibitors rofecoxib and nimesulide, we were able to delay tumor-mediated wasting in vivo. Overall, our results suggest that cachexia is a multigenetic disease that will require complex combinations of drugs for an effective therapeutic intervention.     

Mechanism of increased lipolysis in cancer cachexia

Loss of fat mass is a key feature of cancer cachexia and has been attributed to increased adipocyte lipolysis. The mechanism behind this alteration is unknown and was presently investigated. We studied mature s.c. fat cells and differentiated preadipocytes from 26 cancer patients with and without cachexia. Hormone-induced lipolysis and expression of lipolysis-regulating genes were determined together with body composition and in vivo lipolytic activity (fasting plasma glycerol or fatty acids related to body fat). Body fat was reduced by 40% and in vivo lipolytic activity was 2-fold increased in cachexia (P = 0.001). In mature adipocytes, the lipolytic effects of catecholamines and natriuretic peptide were 2- to 3-fold increased in cachexia (P < 0.001). This was completely counteracted by inhibiting the rate-limiting lipolysis enzyme hormone-sensitive lipase (HSL). In cachexia, the expression levels of HSL mRNA and protein were increased by 50% and 100%, respectively (P = 0.005-0.03), which strongly correlated with in vitro lipolytic stimulation (r = 0.7-0.9). The antilipolytic effect of insulin in mature fat cells and the stimulated lipolytic effect in differentiated preadipocytes were unaltered in cachexia. Patients who lost weight due to other factors than cancer cachexia had no change in adipocyte lipolysis. In conclusion, adipocyte lipolysis is increased in cancer cachexia not due to nonepigenic factors or to weight loss per se, but most probably because of enhanced expression and function of adipocyte HSL. The selective inhibition of this enzyme may prevent fat loss in cancer patients.     

Gut microbiome and pancreatic cancer cachexia: An evolving relationship

Nearly 80% of patients with pancreatic ductal adenocarcinoma (PDAC) develop cachexia along their disease course. Cachexia is characterized by progressive weight loss, muscle wasting, and systemic inflammation and has been linked to poorer outcomes and impairments in quality of life. Management of PDAC cachexia has historically involved a multidisciplinary effort comprised of nutritional support, pancreatic enzyme replacement therapy, and/or pharmacologic interventions. Despite current interventions to mitigate PDAC cachexia, a significant proportion of patients continue to die from complications associated with cachexia underscoring the need for novel insights and treatments for this syndrome. We highlight the feasibility and effectiveness of a recent enteral feeding prospective trial at our institution to improve cachexia outcomes in patients with advanced PDAC. Additionally, we were among the first to characterize the stool microbiome composition in patients with advanced PDAC receiving enteral feeding for the treatment of cachexia. Novel insights into the relationship between enteral nutritional support, cachexia, and the gut microbiome are presented. These promising results are discussed in the context of a potential ability to modulate the stool microbiome as a new interventional strategy to mitigate PDAC cachexia.