Camptothecin(CPT)和Cytosine arabinoside(Ara-C)联合应用对MOLT-4细胞株周期特异性凋亡的影响

目的以急性T淋巴细胞白血病细胞株MOLT-4为模型,探讨作用于同一细胞周期的化疗药物 Camptothecin(CPT)和Cytosine arabinoside(Ara-C)联合应用时是否具有抗癌增效作用、引起细胞凋亡的周期时相性是否发生改变及对细胞周期检测点(ckeckpoint)的影响.方法喜树碱(CPT)(0.25 μmol/L),阿糖胞苷(Ara-C)(1.00 μmol/L),及喜树碱(CPT)(0.25 μmol/L) 阿糖胞苷(Ara-C)(1.00 μmol/L) 二药共同诱导急性早幼粒白血病细胞株MOLT-4细胞4 h,分别采用激光共聚焦显微镜(Confocal)观察其细胞的形态变化,采用Sub-G1法,API法及cyclins/DNA双参数法,运用流式细胞术分析凋亡、凋亡细胞的周期时相性及CyclinE的表达规律.以Western blot印迹法检测Bcl-2蛋白的表达.结果喜树碱和阿糖胞苷联合应用时,凋亡细胞的数目明显增加,二者具有协同效应.发生凋亡的细胞大多数仍然是S期细胞.CyclinE的表达升高,bcl-2蛋白的表达降低.结论作用于同一细胞周期的化疗药物CPT和Ara-C联合应用时,具有协同效应但并不改变细胞周期的作用点(Checkpoint).CyclinE和Bcl-2蛋白似乎在药物作用时起着关键性的调节作用,并对检测点的敏感性产生重要影响.     

细胞凋亡与细胞增殖协同作用的研究

在S期,砷剂在G1/S期,TNF-α或抗Fas抗体在G1/S期), PBLs不存在这种打击依赖性的差异.未经PHA刺激的PBLs对凋亡打击无应答,PBLs经PHA刺激后进入凋亡, 在外界打击作用下凋亡明显增加,在用咖啡因废除细胞周期检测点后对打击敏感性降低.拥挤或饥饿的PBLs同样对凋亡诱导无应答.结论:大多数细胞凋亡具有周期特异性,细胞周期改变可导致凋亡模式和时相的改变.细胞凋亡与增殖的协同作用是细胞周期和凋亡信号整合的重要机制.     

咖啡因对喜树碱诱导Molt-4细胞凋亡的影响

背景与目的:有报道认为咖啡因(caffeine)可以作用于细胞周期检测点,从而影响细胞周期的进程,而这种效应对于肿瘤细胞凋亡的影响尚存在争议。本研究探讨咖啡因对喜树碱诱导Molt-4细胞凋亡的作用及其对细胞周期检测点的效应。方法:用喜树碱诱导细胞凋亡,以咖啡因作为干扰细胞周期检测点的因素。用API法(AnnexinⅤ-propidiumiodide,AnnexinⅤ/PI)及亚G1峰法对细胞凋亡率以及凋亡发生的周期特异性进行检测分析。结果:2.0～20.0mmol/L的咖啡因对处于对数生长期Molt-4细胞增殖没有影响。喜树碱能诱导Molt-4细胞产生以S期细胞为主的细胞周期特异性凋亡,0.15μmol/L喜树碱作用4、6h,细胞凋亡率分别为(23.69±2.26)%、(36.99±1.42)%;10.0mmol/L咖啡因能显著抑制这种细胞凋亡,与0.15μmol/L喜树碱联合作用4、6h后,细胞凋亡率分别下降至(4.79±0.64)%和(2.69±0.56)%。去除咖啡因后,凋亡细胞明显增多,去除4、6h后细胞凋亡率升至(46.23±0.21)%和(55.81±0.41)%,且仍以S期细胞为主。结论:咖啡因可以抑制喜树碱诱导细胞凋亡。作为影响细胞周期检测点的药物,咖啡因可以明显屏蔽检测点对损伤细胞的监督,抑制细胞凋亡,但其作用是一过性的、可以逆转的。     

化学药物按其对细胞周期作用的分类(译文)

一、时相特异性药物与周期特异性药物抗癌药物除了它们的生化作用机制外,它们也干扰细胞周期中不同时相的细胞生长和复制。A 类药物称做周期特异性药物,因为它们作用于整个细胞增殖周期,而对 G。期(休止期)细胞无作用。B 类药物称为时相特异性药物,它仅干扰细胞周期的一个特殊时相,如 G_1S、G_2或 M 期。处在不敏感时相的细胞能在任何剂量水平下存活,较高剂量时则呈坪型曲线。BRUCE 起初将氮芥(和γ—射线)归为第三类,即周期非特异性药物,因为     

顺铂联合土贝母皂苷甲对宫颈癌Hela细胞的增殖抑制作用研究

目的:探讨土贝母皂苷甲与顺铂单独及联合应用对人宫颈癌Hela细胞的抑制作用,以期对临床上药物治疗宫颈癌提供新的思路和理论依据.方法:采用MTT法检测单用土贝母皂苷甲、DDP及两药联合时对HeLa细胞的生长抑制率.用流式细胞仪测定细胞周期变化.结果:土贝母皂苷甲组(20μg/ml、40μg/ml、80μg/ml)、顺铂组(10μmol/L)及联合组(40μg/ml土贝母皂苷甲+10μmol/L顺铂)宫颈癌Hela细胞株均有不同程度的生长抑制作用;土贝母皂苷甲组随着药物浓度增加,作用时间延长,对Hela细胞的生长抑制率逐渐升高;土贝母皂苷甲与顺铂联合用药较单一用药对Hela细胞的生长抑制率增高,具有浓度―时间依赖性.流式细胞仪分析结果显示:土贝母皂苷甲组、顺铂组及联合组作用于宫颈癌Hela细胞株24小时,可阻滞细胞周期于G2/M期.结论:土贝母皂苷甲对宫颈癌HeLa细胞株具有生长抑制作用,且呈剂量和时间依赖性,其与顺铂联合应用具有协同作用,联合应用可减少顺铂用药剂量;土贝母皂苷甲与顺铂单独及联合作用于宫颈癌Hela细胞株24h可阻滞细胞周期于G2/M期.     

大蒜素与细胞周期特异性化疗药联合应用抗肿瘤的实验研究

目的:探讨大蒜素对人胃癌细胞株BGC-823、SGC7901生长的影响及其与细胞周期特异性化疗药联合应用抗肿瘤作用.方法:M丌法测定细胞增殖抑制率并测定药物半数抑制率(IC50);流式细胞仪检测细胞周期的改变,大蒜素与NVB、5-FU、MMC、PDD四种化疗药联合应用,观察细胞毒活性的改变.结果:大蒜素对BGC-823和SGC-7901两种细胞的生长均有明显的抑制作用,72h IC50分别为:30μg/ml和20μg/ml.以72h IC50浓度大蒜素分别作用于两种胃癌细胞株24h、48h后,流式细胞仪检测与对照组比G0/G1期细胞减少,G2/M期细胞明显增加,提示两种胃癌细胞株经大蒜素处理后,细胞周期阻滞于G2/M期.大蒜素与四种化疗药联合应用,结果发现作用于BGC823细胞,NVB72h的IC50值由原来单独应用时的9.0μg/ml降至2.25μg/ml.作用于SGC-7901细胞,NVB72h的IC50值由原来单独应用时的43.0μg/ml降至12.5μg/ml,显示大蒜素与作用于G2/M期的细胞周期特异性化疗药NVB联合应用时可增强其对肿瘤细胞的杀伤作用.结论:大蒜素可使BGC-823和SGC-7901两种细胞的增殖受到抑制,细胞周期被阻滞在G2/M期.大蒜素与G2/M期特异性化疗药联合应用,可能具有协同抗肿瘤作用.     

大蒜素协同抗癌药对肿瘤细胞杀伤作用的研究

目的:探讨大蒜素对人胃癌细胞系MGC-803和SGC-7901细胞周期的影响及其与周期特异性药物联合使用,增强抗癌药物对肿瘤细胞的杀伤作用.方法:苔盼蓝拒染法检测细胞增殖抑制率以观察大蒜素对胃癌细胞的增殖抑制作用;流式细胞仪及瑞士-姬姆萨染色光镜观察检测细胞周期的改变;3μg/ml大蒜素与周期特异性抗癌药物博莱霉素A5和长春新碱联合使用,观察药物细胞毒活性的改变.结果:大蒜素可抑制MGC-803细胞生长,24h IC50为6.4μg/ml,也可抑制SGC-7901细胞的生长,24h IC50为7.3μg/ml;以3μg/ml、6μg/ml、9μg/ml终浓度大蒜素分别作用两种胃癌细胞系24h后,与对照组比较,G0/G1细胞周期百分率明显减少,而G2/M期明显增加(P＜0.01);6μg/ml大蒜素作用培养细胞24h后,与对照组比较细胞分裂指数明显增加.提示两种细胞系经大蒜素处理后,细胞周期阻滞于M期;大蒜素与两种抗癌药物联合使用,作用于MGC-803细胞,BLM A5和VCR的24h IC50值分别由单独应用的1.210μg/ml和0.125μg/ml下降到0.370μg/ml和0.031μg/ml,作用于SGC-7901细胞,BLM A5和VCR的24h IC50值分别由单独应用的1.760μg/ml和0.287μg/ml下降到0.680μg/ml和0.074μg/ml,显示低剂量大蒜素增强了抗癌药物对肿瘤细胞的杀伤作用.结论:大蒜素可使MGC-803及SGC-7901两种细胞周期阻滞于M期;大蒜素与M期特异作用抗癌药物联合使用,具有协同抗肿瘤作用.     

全反式维甲酸提高人结肠癌细胞亚株SW480/M5对奥沙利铂敏感性

目的探讨全反式维甲酸(all-trans retinoic acid,ATRA)提高人结肠癌细胞亚株SW480/M5对奥沙利铂(oxaliplatin,L-OHP)敏感性的可能机制.方法 MTT法筛选ATRA和L-OHP实验浓度.流式细胞仪检测ATRA对肿瘤细胞周期影响.分别用ATRA、L-OHP、ATRA联合L-OHP作用SW480/M5细胞,MTT法检测药物对肿瘤细胞抑制率,流式细胞仪检测肿瘤细胞周期及凋亡率,原子光谱吸收仪检测肿瘤细胞DNA含铂(Pt)量. 结果L-OHP抑制SW480/M5细胞增殖的GI50为58.0mg/L,主要阻滞肿瘤细胞在S和G2/M期.ATRA 8.0μmol/L作用24小时后,G1期细胞减少,S期细胞增多;作用72小时后,S期和G2/M期细胞增加并明显抑制肿瘤细胞增殖.8.0μmol/LATRA作用至48小时后联合L-OHP,两药联合由相加作用转变为协同作用;联合用药后S期和G2/M期细胞明显增多,细胞DNA含Pt量显著增加,呈时效依赖性.相对于单独用药,联合用药并不上调肿瘤细胞凋亡率.结论ATRA通过改变SW480/M5细胞周期和提高细胞DNA含Pt量,明显增加肿瘤细胞对L-OHP敏感性.     

Vitexicarpin诱导肺癌A549细胞凋亡和对细胞周期作用的研究

目的:研究蔓荆子黄素(Vitexicarpin)对人肺癌细胞株A549细胞增殖和凋亡的影响及其机制.方法:设计长春新碱(Vineristine)阳性对照组和空白阴性对照组及不同浓度的Vitexiearpin溶液作用于A549细胞,应用细胞增殖抑制试验和流式细胞仪检测技术,观察Vitexicarpin对A549细胞增殖的影响,以及其诱导A549细胞在不同时段的凋亡情况和对细胞周期的影响.结果:Vitexicarpin浓度为10μmol/L时对A549细胞的增殖抑制率超过50%,IC50为8.21μmol/L.另外,Vitexicarpin能有效诱导A549细胞凋亡.从Vitexicarpin作用4h开始,细胞被阻滞于G2/M期.随时间增加,G1/S期细胞逐渐减少,G2/M期细胞逐渐增多,且凋亡细胞逐渐增多.结论:Vitexicarpin能抑制A549细胞增殖,诱导A549细胞发生凋亡,将细胞阻滞于G2/M期是其可能作用机制.     

白藜芦醇对黑色素瘤细胞增殖的抑制作用

目的:探讨白藜芦醇对黑色素瘤细胞WM239增殖、细胞周期及凋亡的影响。方法:MTT法检测白藜芦醇对WM239细胞增殖的影响;流式细胞术检测白藜芦醇对WM239细胞周期及凋亡的影响。结果:12.5～200μmol/L的白藜芦醇作用于WM239细胞48h和72h后,对其增殖具有一定的抑制作用,作用72h时,浓度>50μmol/L其抑制率>50%,且抑制程度与药物浓度呈正相关。其中0、25、50和100μmol/L药物与WM239细胞作用48h后,凋亡率分别为0.1%、9.7%、8.9%和19.3%,处理组与未处理组相比细胞凋亡明显增加,G0/G1期细胞分别为71.9%、77.3%、81.0%和83.7%,S期分别为21.5%、17.9%、16.0%和14.6%,G2/M期为6.5%、4.8%、2.9%和1.8%,细胞周期阻滞于G1期,S期和G2期细胞比例下降,剂量依赖关系明显。结论:白藜芦醇可以抑制WM239细胞的增殖,引起细胞周期改变,凋亡细胞明显增加。     

Neoadjuvant therapy in pancreatic cancer

Pancreatic cancer is the fourth leading cause of cancer deaths in the United States. Surgical resection offers the only hope of cure, though the addition of chemoradiation in the adjuvant setting has been shown to improve survival over surgery alone. Many patients are unable to receive adjuvant therapy due to prolonged postoperative recovery. For this reason, administration of chemoradiation preoperatively (neoadjuvant) has been proposed as an alternative to postoperative treatment. In patients with resectable disease, neoadjuvant therapy results in similar survivals compared to postoperative therapy, with a greater proportion of patients able to complete treatment. For selected patients with borderline or unresectable disease, neoadjuvant therapy offers the potential for tumor downstaging and increasing the likelihood of a margin-negative resection. This article reviews the use of neoadjuvant therapy in the treatment of pancreatic cancer.     

Role of radiation therapy in the treatment of melanoma

Melanoma has been widely described as radioresistant but this should not be construed as meaning that melanoma is radioincurable. Many melanoma cell lines are as radiosensitive as other tumors commonly treated successfully with radiotherapy (RT). The use of RT requires careful planning resulting in the administration of a tumoricidal dose to the tumor cells with adequate sparing of normal tissues. RT has been used for primary therapy, postresection adjuvant therapy and palliation of symptomatic melanoma. Curative RT has been given for uveal melanoma yielding patient survival equivalent to enucleation. RT has been administered to patients with unresectable disease yielding relatively favorable results. As an adjuvant therapy postoperatively, RT has been used selectively to improve local disease control. Finally, RT is used successfully as a palliative maneuver for symptoms related to distant metastatic melanoma in patients with incurable disease.     

Successful treatment of metastatic androgen-independent prostate carcinoma in a transsexual patient

The occurrence of prostate carcinoma in transsexual patients has rarely been reported. These cases present a unique challenge in that such patients are effectively receiving androgen deprivation therapy. By definition, their disease is androgen-independent prostate cancer, and the role of local therapy is undefined. We report on a male-to-female transsexual patient with metastatic prostate cancer treated successfully with combination chemotherapy after previous standard therapy failed.     

A randomized phase III study of neoadjuvant hormonal therapy in patients with localized prostate cancer

The primary objective of this randomized trial is to evaluate the benefit of the addition of neoadjuvant hormonal therapy to escalated-dose external-beam radiation therapy in the treatment of patients with intermediate-risk carcinoma of the prostate. A secondary objective of this study is to determine prognostic factors for radiation response. All patients will have tissue oxygenation measured and biopsies taken before treatment at the time of fiducial marker insertion for radiation treatment planning and daily monitoring. In addition, patients randomized to the neoadjuvant bicalutamide arm will be asked to consider having these studies repeated before initiation of radiation therapy (after 3 months of hormonal therapy).     

Novel developments in angiogenesis cancer therapy

A greater understanding of the factors and pathways controlling angiogenesis in tumours has allowed the development of a number of agents that selectively inhibit the pathways mediating that activity. The results to date of clinical trials with such agents and future research opportunities are reviewed.     

Pathways and therapeutic targets in melanoma

This review aims to summarize the current knowledge of molecular pathways and their clinical relevance in melanoma. Metastatic melanoma was a grim diagnosis, but in recent years tremendous advances have been made in treatments. Chemotherapy provided little benefit in these patients, but development of targeted and new immune approaches made radical changes in prognosis. This would not have happened without remarkable advances in understanding the biology of disease and tremendous progress in the genomic (and other “omics”) scale analyses of tumors. The big problems facing the field are no longer focused exclusively on the development of new treatment modalities, though this is a very busy area of clinical research. The focus shifted now to understanding and overcoming resistance to targeted therapies, and understanding the underlying causes of the heterogeneous responses to immune therapy.     

连接蛋白43基因治疗鼠C6脑胶质瘤的体内实验研究

目的 研究连接蛋白（Cx）43基因抑制脑胶质瘤生长的作用。方法 将Cx43基因表达缺失的大鼠C6胶质瘤细胞（对照组）和转染Cx43 cDNA的C6细胞（转染组）种植于SD大鼠右侧尾状核,荷载C6脑胶质瘤鼠用Cx 43 cDNA原位治疗（治疗组）,并以空载体治疗作为对照（空载组）,每组10只,观察各组大鼠一般情况、生存期、MRI动态变化及病理改变,通过原位杂交及免疫组化染色检测肿瘤Cx43 mRNA及蛋白表达,以AgNOR平均计数检测增殖活性,以Tunel法检测细胞凋亡。结果 对照组和空载组大鼠均于3周内死亡;转染组6只大鼠和治疗组8只大鼠观察120 d内无自然死亡。除治疗组1只尚有残瘤外,余瘤体消失,转染组和治疗组肿瘤细胞均有Cx43 mRNA及蛋白表达,且增殖治疗组1只尚有残瘤外,余瘤体消失。转染组和治疗组肿瘤细胞均有Cx43 mRNA及蛋白表达,且增殖活性下降,但凋亡不增加。结论 转染Cx43基因后的C6胶质瘤细胞致瘤性显著降低,且对荷载脑胶质瘤鼠具有明显的治疗作用,有可能成为恶性胶质瘤基因治疗的优先靶的之一。     

Targeted therapy in nuclear medicine--current status and future prospects.

In recent years, a number of new developments in targeted therapies using radiolabeled compounds have emerged. New developments and insights in radioiodine treatment of thyroid cancer, treatment of lymphoma and solid tumors with radiolabeled monoclonal antibodies (mAbs), the developments in the application of radiolabeled small receptor-specific molecules such as meta-iodobenzylguanidine and peptides and the position of locoregional treatment in malignant involvement of the liver are reviewed. The introduction of recombinant human thyroid-stimulating hormone and the possibility to enhance iodine uptake with retinoids has changed the radioiodine treatment protocol of patients with thyroid cancer. Introduction of radiolabeled mAbs has provided additional treatment options in patients with malignant lymphoma, while a similar approach proves to be cumbersome in patients with solid tumors. With radiolabeled small molecules that target specific receptors on tumor cells, high radiation doses can be directed to tumors in patients with disseminated disease. Radiolabeled somatostatin derivatives for the treatment of neuroendocrine tumors are the role model for this approach. Locoregional treatment with radiopharmaceuticals of patients with hepatocellular carcinoma or metastases to the liver may be used in inoperable cases, but may also be of benefit in a neo-adjuvant or adjuvant setting. Significant developments in the application of targeted radionuclide therapy have taken place. New treatment modalities have been introduced in the clinic. The concept of combining therapeutic radiopharmaceuticals with other treatment modalities is more extensively explored.     

Advances in combined radiation therapy for the management of rectal cancer

Significant advances have been made in the use of adjuvant radiation for patients with localized rectal cancer. Recent progress in adjuvant postoperative radiation regimens relates to the integration of systemic therapy into radiation, as well as redefining the techniques and sequences for both modalities. The adjuvant radiation management approach in both North America and Europe has been shifting towards preoperative adjuvant therapy to promote sphincter-preserving surgery and to decrease acute and late toxicity. Although 5-fluorouracil-based chemotherapy in combination with radiation remains the standard adjuvant therapy for rectal cancer, the integration of novel chemotherapeutic agents and biologic modulators remains an active area of investigation.     

泰索帝联合吡柔比星治疗晚期乳腺癌的疗效观察

目的：观察泰索帝联合吡柔比星治疗晚期乳腺癌临床疗效及不良反应。方法：26例均有组织病理学细胞学诊断及可评价客观指标。采用泰索帝75mg/m^2 dl,静脉滴注1小时，用泰索帝前1天口服地塞米松10mg，连续3天。吡柔比星40mg/m^2 d2化疗。21天为1周期，2个周期评价疗效。结果：26例可评价疗效和不良反应。CR3例，PR 16例，NC5例，PD2例，有效率73．1％。不良反应主要为白细胞减少Ⅲ度占34．6％，Ⅳ度占26．9％，脱发Ⅱ度占46．2％，Ⅲ度占23．1％，腹泻Ⅱ度占34．6％Ⅲ度占23．1％。结论：泰索帝联合吡柔比星治疗晚期乳腺癌有效率较高，不良反应可以耐受。