放射外科治疗脑星形胶质细胞瘤的病理改变对比研究

目的观察放射外科治疗后星形胶质细胞瘤的病理、超微结构及肿瘤相关因子Ki-67、血管内皮生长因子(VEGF)、微血管密度(MVD)的变化。 方法收集四川省人民医院神经外科自1995年11月至2008年7月间行放射外科治疗后手术切除的脑胶质瘤标本25例（治疗组）,同期未接受任何放、化疗原发性脑胶质瘤标本25例作为对照组,2组均由术者留取8例戊二醛固定的电镜标本,观察标本常规病理(HE染色)及肿瘤中心、边缘及瘤周2cm范围内水肿组织超微结构的改变;采用免疫组化染色检测标本Ki-67、VEGF、MVD的表达。 结果 治疗组星形细胞瘤坏死程度与肿瘤级别呈正相关(r=0.649,P=0.001);电镜下放疗组肿瘤细胞的细胞器、微血管、血脑屏障分别在肿瘤的中心、肿瘤边缘、瘤周水肿脑组织发生不同程度的变性坏死,而对照组胶质瘤细胞器完整;免疫组化染色结果显示2组标本Ki-67阳性细胞百分率、VEGF蛋白表达和MVD与肿瘤分级均呈正相关关系(P＜0.05),与对照组同级别胶质瘤比较,治疗组Ki-67阳性细胞百分率、MVD较低,差异均有统计学意义(P＜0.05)。 结论接受放射外科治疗后肿瘤细胞出现不同程度的变性、坏死、凋亡、微血管血脑屏障破坏,为胶质瘤个体化综合性治疗提供重要佐证。     

VEGF在人脑胶质瘤中的表达与肿瘤增殖及肿瘤血管生成的关系

目的研究血管内皮细胞生长因子(vascular endothelial growth factor,VEGF)在人脑胶质瘤中的表达与肿瘤增殖及血管生成的关系。方法应用免疫组化技术和形态定量分析法,检测98例手术切除脑胶质瘤中VEGF表达、PCNA标记指数(PCNA LI)、微血管密度(Microvessel density,MVD)表达。结果(1)肿瘤细胞及血管内皮细胞均可以表达VEGF,阳性颗粒分布于肿瘤胞浆中;(2)高级别肿瘤PCNA、LI、MVD显著高于低级别肿瘤(P<0.05);VEGF表达阳性肿瘤的PCNA、LI、MVD显著高于VEGF表达阴性肿瘤(P<0.05);(3)在星形细胞肿瘤中,随着MVD的增大,VEGF在肿瘤血管内皮的染色率逐渐增加,与肿瘤的MVD存在正相关关系(r值为0.44,P<0.01)。结论脑胶质瘤的VEGF表达与MVD呈正相关关系,VEGF在肿瘤细胞增殖及血管再生过程中起重要作用。     

骨髓基质干细胞移植对大鼠胶质瘤局部微环境的影响

目的:探讨骨髓基质干细胞(BMSCs)移植对脑胶质瘤模型大鼠(荷瘤大鼠)胶质瘤的影响。方法:观察BMSCs培养上清液对C6胶质瘤细胞增殖活性、细胞周期的影响。观察脑内移植BMSCs对胶质瘤核增殖抗原(PCNA)表达阳性率、脑内胶质瘤微血管计数的影响及荷瘤鼠生存期的改变。结果:BMSCs培养上清液对胶质瘤细胞增殖没有明显的影响;BMSCs可抑制肿瘤边缘及卫星灶的肿瘤增殖,对肿瘤内部的细胞增殖没有明显影响。移植BMSCs后肿瘤边缘及卫星灶的微血管计数未见明显改变。移植BMSCs后的荷瘤大鼠脑内胶质瘤水肿有所减轻。结论:BMSCs移植可轻度抑制荷瘤鼠脑内胶质瘤细胞的增殖。     

Effective inhibition of irradiation on human gliomas growth in vitro and in vivo after epidermal growth factor receptor silencing with RNA interference

In this study, we found that irradiation in the presence of small interfering RNA-epidermal growth factor receptor (EGFR) arrested U373 glioma cells in G? and G? phases, delayed cell cycle progression, and effectively inhibited cell proliferation compared with cells that received only radiotherapy. In addition, combined therapy enhanced the percent of apoptotic U373 cells in vitro and also reduced the tumor size and increased the survival rate in tumor xenograft studies. This study demonstrates the antitumor activity of ionizing radiation therapy in combination with small interfering RNA-EGFR in gliomas both in vitro and in vivo and provides a scientific rationale for targeting EGFR to enhance the sensitivity to radiotherapy in patients with glioblastoma multiforme.     

Scatter factor/hepatocyte growth factor (SF/HGF) content and function in human gliomas

Scatter factor/hepatocyte growth factor (SF/HGF) is a pleiotrophic cytokine that stimulates motility and invasion of several cancer cell types and induces angiogenesis. Its receptor MET is a transmembrane tyrosine kinase encoded by the C-MET proto-oncogene. To assess the potential relevance of SF/HGF in gliomas we performed functional studies in vivo and in vitro, expression analyses and correlative studies. We showed that both SF/HGF and MET are expressed in gliomas in vivo and are upregulated during transition from low grade to malignant glioma. When SF/HGF cDNA was transfected into glioma cells that expressed the MET receptor the cells formed considerably larger and more vascularized intracranial tumors in vivo than SF/HGF negative control clones. In other glioma cells, which constitutively expressed both SF/HGF and MET, we abolished SF/HGF expression by antisense ribozyme-targeting, which led to a significant decrease in tumorigenicity and tumor growth. In vitro SF/HGF strongly stimulated glioma cell motility and to a lesser degree proliferation. SF/HGF also strongly increased endothelial cell motility in vitro and extracts of tumors derived from SF/HGF-transfected glioma cells were more mitogenic for endothelial cells and more angiogenic in the rat cornea angiogenesis assay than extracts from control tumors. In a three-dimensional in vitro angiogenesis assay basic fibroblast growth factor (bFGF) was found to synergize with either SF/HGF or vascular endothelial growth factor (VEGF) in inducing endothelial capillary-like tubes, whereas neither SF/HGF nor VEGF alone or in combination were effective. Interestingly, while both VEGF and SF/HGF levels appeared to be increased in malignant gliomas compared with low grade ones, this was not the case for bFGF of which biologically relevant levels were already present in low grade gliomas. It thus seems that bFGF alone is insufficient to induce angiogenesis in gliomas but may act synergistically with either VEGF and/or SF/HGF when these become upregulated during malignant progression. In conclusion, we showed that SF/HGF may contribute to glioma progression by stimulating tumor invasiveness, proliferation and neovascularization.     

ABCG2与VEGF、VEGFR和CD34在胶质瘤组织芯片中的共表达

目的 探讨ABCG2在胶质瘤血管形成过程中与VEGF、VEGFR和CD34的关系和共表达.方法 构建布有90例各级别人脑胶质瘤的组织芯片,用EnVision法的免疫组织化学染色,分别分析ABCG2、VEGF、VEGFR和CD34在胶质瘤中的表达率、微血管密度(MVD)及其相关性,并以免疫荧光染色和激光共聚焦显微镜检测CD34和ABCG2共表达的细胞.结果 ABCG2、VEGF、VEGFR和CD34的表达率均随胶质瘤恶性程度增加而增高;并且ABCG2表达水平与肿瘤MVD显著相关,γ=0.540,P＜0.001.ABCG2阳性表达的Ⅲ、Ⅳ级肿瘤标本MVD比Ⅰ、Ⅱ级高.VEGF、VEGFR和ABCG2均为阳性表达的肿瘤标本MVD平均值显著高于ABCG2阴性表达者,P＜0.001.在CD34显示的肿瘤血管腔壁上同时见到了ABCG2的表达.结论 胶质瘤的恶性进展除了与公认的肿瘤细胞和肿瘤血管内皮细胞共表达的VEGF和VEGFR高表达相关,还与ABCG2高表达相关.在同一根血管上同时见到了ABCG2(肿瘤干细胞标志蛋白)和CD34(内皮细胞标志蛋白)的共表达,表明肿瘤干细胞除了生成肿瘤细胞,还有可能生成肿瘤血管内皮细胞.     

LAT1表达与人脑胶质瘤病理级别、增殖和血管形成的关系

目的探讨大型氨基酸转运载体1(LAT1)在人脑胶质瘤组织中的表达水平及其与胶质瘤病理学特征、细胞增殖以及血管形成的关系。方法采用免疫组化方法检测LAT1、Ki-67和CD34在62例人脑胶质瘤组织中的表达,计算Ki-67标记指数(Ki-67 LI)和微血管密度(MVD)。结果LAT1在胶质瘤中高表达,其免疫阳性染色既定位于瘤细胞也定位于血管内皮;LAT1表达随胶质瘤病理级别升高而明显增强(P=0.000),在高恶性度胶质瘤中LAT1表达明显强于低恶性度胶质瘤(P=0.002);LAT1表达与胶质瘤Ki-67标记指数(P=0.003)和微血管密度(P=0.000)都存在明显正相关。结论 LAT1与胶质瘤的发生和发展关系密切,可能在胶质瘤的恶性增殖和血管形成中发挥重要作用。     

OPN和VEGF在脑胶质瘤中的表达及其与预后的关系

目的探讨骨桥蛋白(OPN)和血管内皮生长因子(VEGF)在脑胶质瘤中的表达及其与各临床病理特征的关系,评价OPN和VEGF对判断患者预后的价值。方法免疫组化检测60例脑胶质瘤和15例正常脑组织中OPN和VEGF的表达,并对OPN和VEGF的表达与脑胶质瘤临床病理特征及患者生存时间进行统计学分析。结果OPN、VEGF在脑胶质瘤中表达阳性率分别为70.0%、75.0%,在正常脑组织中表达阳性率分别为20.0%、26.7%,肿瘤中OPN和VEGF表达显著高于正常组织。OPN表达在不同肿瘤直径、瘤周脑水肿(PTBE)和病理分级中的差异有统计学意义。VEGF表达在不同PTBE和病理分级中的差异有统计学意义。对OPN和VEGF表达阳性和阴性患者生存率分析的差异也有统计学意义,并提示OPN和VEGF为负性预后因子。OPN与VEGF之间关系呈正相关。结论OPN和VEGF在脑胶质瘤中高表达,两者均反映了脑胶质瘤的生物学特性,并与患者预后有关,OPN和VEGF阳性表达提示预后不良。     

缺氧诱导因子-lα和血管内皮生长因子在人脑胶质瘤中的表达及意义

目的:探讨缺氧诱导因子-1α(HIF-1α)、血管内皮生长因子(VEGF)和微血管密度(MVD)在人脑胶质瘤中的表达情况,分析三者的关系及其意义。方法:应用免疫组化方法分析62例人脑胶质瘤中HIF-1α、VEGF、和MVD的表达情况。结果:本组HIF-1α的总阳性表达率是66.1%,它们在正常脑组织和Ⅰ-Ⅱ、Ⅲ、Ⅳ肿瘤组织的阳性率分别为0%、39.3%、81.8%、100%与正常对照组比较有显著性差异(P<0.01)。HIF-1α表达水平与胶质瘤恶性度存在相关性(P<0.01)。VEGF在HIF-1α阳性组中的阳性率(95.1%)明显高于HIF-1α阴性组中的VEGF的阳性率47.6%(P<0.01)。结论:HIF-1α和VEGF的表达与MVD存在正相关关系;VEGF与HIF-1α表达呈正相关性,二者与人脑胶质瘤的病理分级呈正相关,与脑胶质瘤新生血管生成有关。     

Evidence for a constitutive, verapamil-sensitive, non-P-glycoprotein multidrug resistance phenotype in malignant glioma that is unaltered by radiochemotherapy in vivo

Human malignant gliomas are commonly resistant to chemotherapy. Here, we examined the role of the multidrug resistance (mdr) mechanism in the chemoresistance of these tumors, using a twofold approach: (i) by assessing a possible mdr phenotype before and after chronic drug exposure of glioma cells in vitro, and (ii) by assessing the modulation of expression of the mdr-associated P-glycoprotein (Pgp) using radiotherapy and serial cycles of chemotherapy in human glioblastoma patients in vivo. T98G, and to a lesser degree, LN-229 human malignant glioma cells exhibit a constitutive mdr phenotype as determined by the modulation of dye transport and by the augmentation of chemosensitivity by the mdr antagonist, verapamil. Thus, coexposure to verapamil enhances the cytotoxicity of vincristine, doxorubicin and VM26 in T98G cells and that of vincristine in LN-229 cells. Chronic exposure of the cells to low concentrations of vincristine and doxorubicin, but not VM26, topotecan or BCNU, moderately enhances the mdr-like phenotype, as assessed by drug expulsion assays. However, chronic exposure to increasing drug concentrations does not significantly alter the sensitivity to the respective drugs. These data are consistent with a constitutive, but not drug-inducible, mdr-like drug resistance in glioma cells in vitro. Immunocytochemical analysis of human malignant gliomas in vivo reveals that Pgp expression is more abundant in endothelial cells within the gliomas, than in the glioma cells proper. Importantly, Pgp expression is unaltered by radiochemotherapy, assessed by comparative immunocytochemistry of glioma specimens obtained serially before and after radiochemotherapy. We conclude that (i) glioma cells exhibit constitutive mdr-like drug resistance that is not significantly altered by chronic drug exposure in vitro; (ii) endothelial cells may play an important role in Pgp-mediated drug resistance of gliomas in vivo; (iii) radiotherapy and repeated chemotherapy cycles do not modulate Pgp expression in human malignant gliomas in vivo; (iv) there is preliminary evidence for a non-Pgp, verapamil-sensitive drug transport activity in glioma cells. Received: 17 May 1999 / Revised, accepted: 16 August 1999     

2-甲氧基雌二醇对神经胶质瘤荷瘤小鼠的抑瘤作用研究

目的 探讨2-甲氧基雌二醇(2-ME)对神经胶质瘤U251细胞移植瘤的增殖抑制、凋亡及可能的分子机制。方法 构建胶质瘤裸鼠移植瘤模型,经2-ME治疗后分别记录移植瘤的重量、体积; 通过移植瘤HE、免疫组化、TUNEL染色分析2-ME对移植瘤的增殖抑制、凋亡及对Bcl-2、VEGF表达水平的影响; 检测2-ME对裸鼠肝肾功能的影响。结果 2-ME对肿瘤的体积和重量均有抑制作用; HE染色显示实验组出现不同程度的肿瘤细胞密度减低; 免疫组化染色显示,随着2-ME水平的升高,肿瘤组织内Bcl-2、VEGF的表达水平逐渐下降; TUNEL染色显示2-ME诱导裸鼠移植瘤组织细胞凋亡; 肝肾功能检测未见损害发生。结论 2-ME在体内能有效抑制胶质瘤移植瘤的生长、诱导其凋亡,其抗肿瘤作用可能与Bcl-2、VEGF表达水平有关,且无明显毒副作用。     

Angiogenesis in malignant gliomas

One event that accompanies glioma progression is the upregulation of angiogenesis. Low-grade gliomas are moderately vascularized tumors whereas high-grade gliomas show prominent microvascular proliferations and areas of high vascular density. To analyze the molecular mechanisms underlying glioma angiogenesis, we studied the expression of vascular endothelial growth factor (VEGF) and its tyrosine kinase receptors VEGFR-1 and VEGFR-2 during normal brain development and glioma-induced angiogenesis. Our results suggest a paracrine control of angiogenesis and endothelial cell proliferation that is tightly regulated and transient in the embryonic brain, switched off in the normal adult brain, and turned on in tumor cells (VEGF) and the host vasculature (VEGFR-1 and ?2) during tumor progression. It is unknown how VEGF and VEGF receptors are upregulated during glioma angiogenesis, but there is recent evidence that VEGF as well as endogenous inhibitors of angiogenesis could be under control of the tumor suppressor genes p53 and VHL. © 1995 Wiley-Liss, Inc.     

脑胶质瘤的凋亡和相关基因Survivin的表达

目的明确Survivin在脑胶质瘤中的表达和细胞凋亡及微血管密度的相关性。方法检测Survivin在91例脑胶质瘤、20例颅内良性肿瘤的表达用免疫组化法,用流式细胞仪检测其表达和凋亡的关系。用CD34标记及图像定量分析微血管密度。结果Survivin在脑胶质瘤(WHO分级)中阳性率35?91(38.5%),随着脑胶质瘤的恶性程度增高,检出Survivin的阳性率就越高,其中I～II级为6?41(14.6%),III级为12?27(44.4%),IV级为17?23(73.9%)。III级以上恶性脑胶质瘤Survivin表达阳性显著高于II级以下脑胶质瘤(P<0.01)。20例颅内良性肿瘤仅1例表达(5%);Survivin表达强度和CD34标记及图像定量分析的微血管密度呈显著正相关(P<0.05);Survivin阳性比Survivin阴性患者术后生存期缩短(P<0.05)。结论Survivin对脑胶质瘤发生、恶化可能和抑制细胞凋亡、肿瘤血管的形成起重要的作用。     

立体定向植入125I粒子治疗复发脑恶性胶质瘤

目的探讨¹²⁵I粒子近距离放射治疗复发脑胶质瘤的临床分析。方法将40例经手术切除后组织细胞学确诊,且术后复发的恶性胶质瘤患者（采取患者自愿原则）为A组,采用立体定向的方法将¹²⁵I粒子置入胶质瘤内,做肿瘤间质内放疗,同时配合直线粒子加速器放疗。B组以胶质瘤术后采用直线粒子加速器放疗20例患者为对照组。观察客观疗效,临床受益反应,毒性反应,并发症及生存情况。结果 6和12个月累积生存率两组为57.0%比32.6%和20.5%比12.5%（P<0.05）,中位生存时间两组为8.0比4.0个月,平均生存时间两组为8.5比5.5个月（P<0.05）。结论 ¹²⁵I粒子植入治疗脑恶性胶质瘤有疗效肯定,可延长患者生存期,无明显毒副作用,是一种安全有效的辅助治疗方法。     

白藜芦醇对裸鼠胶质瘤模型肿瘤生长的抑制作用

目的 探讨白藜芦醇（RES）不同途径给药对裸鼠胶质瘤模型肿瘤生长的抑制效果。方法 取80只雄性无胸腺裸鼠（BALB/c-nu;21~27日龄,体重10~12 g）,采用U87细胞建立人裸鼠脑胶质瘤原位移植模型,采用随机数字表法分为RES干预组（造模后10 d,开始给药,1次/d,40 mg/kg）和溶剂对照组（造模后10 d,开始给药,1次/d,10 mg/kg;溶剂为0.5%羧甲基纤维素钠）,根据给药途径,RES干预组又分为RES灌胃组和RES经鼻组,溶剂对照组又分为溶剂灌胃组和溶剂经鼻组,每组20只。经鼻给药采用经鼻滴入法。采用Kaplan-Meier法分析生存曲线;造模后14、21、28、35 d测定肿瘤体积;采用CD31标记胶质瘤血管内皮细胞并计算微血管密度（MVD）,采用免疫组化方法检测胶质瘤血管内皮生长因子（VEGF）以及Ki-67表达,采用TUNEL法检测胶质瘤细胞凋亡。结果 与溶剂对照组相比,RES干预组裸鼠生存时间明显延长（P<0.05）,造模后28、35 d肿瘤体积明显缩小（P<0.05）,肿瘤组织MVD明显减小（P<0.05）,肿瘤组织VEGF和Ki-67表达水平明显降低（P<0.05）,肿瘤细胞凋亡率明显增加（P<0.05）,而且,RES经鼻给药较灌胃给药作用更明显（P<0.05）。结论 RES可有效抑制裸鼠胶质瘤模型肿瘤生长,机制可能与抑制肿瘤血管生成和促进肿瘤细胞凋亡有关。与灌胃给药相比,经鼻给药肿瘤抑制效果更好。     

Mechanisms of apoptosis in central nervous system tumors: Application to theory

Apoptosis is a key concept for the successful therapy of brain tumors. This review focuses on the mechanisms of apoptosis occurring spontaneously in malignant gliomas, discusses the different methods employed to assess apoptosis in vivo and in vitro, and considers the value of quantifying apoptosis in surgical biopsies for diagnosis and prognosis. Further, novel strategies to induce apoptosis in human malignant glioma cells are reviewed, including experimental therapy with death ligands, methods for sensitizing glioma cells to the induction of apoptosis, p53 gene transfer, and approaches to target the expression of therapeutic genes selectively to tumor cells.     

Antisense MMP-9 RNA inhibits malignant glioma cell growth in vitro and in vivo

The matrix-degrading metalloproteinases (MMPs), particularly MMP-9, play important roles in the pathogenesis and development of malignant gliomas. In the present study, the oncogenic role of MMP-9 in malignant glioma cells was investigated via antisense RNA blockade in vitro and in vivo. TJ905 malignant glioma cells were transfected with pcDNA3.0 vector expressing antisense MMP-9 RNA (pcDNA-AS-MMP9), which significantly decreased MMP-9 expression, and cell proliferation was assessed. For in vivo studies, U251 cells, a human malignant glioma cell line, were implanted subcutaneously into 4-to 6-week-old BALB/c nude mice. The mice bearing well-established U251 gliomas were treated with intratumoral pcDNA-AS-MMP9-Lipofectamine complex (AS-MMP-9-treated group), subcutaneous injection of endostatin (endostatin-treated group), or both (combined therapy group). Mice treated with pcDNA (empty vector)-Lipofectamine served as the control group. Four or eight weeks later, the volume and weight of tumor, MMP-9 expression, microvessel density and proliferative activity were assayed. We demonstrate that pcDNA-AS-MMP9 significantly decreased MMP-9 expression and inhibited glioma cell proliferation. Volume and weight of tumor, MMP-9 expression, microvessel density and proliferative activity in the antisense-MMP-9-treated and therapeutic alliance groups were significantly lower than those in the control group. The results suggest that MMP-9 not only promotes malignant glioma cell invasiveness, but also affects tumor cell proliferation. Blocking the expression of MMP-9 with antisense RNA substantially suppresses the malignant phenotype of glioma cells, and thus can be used as an effective therapeutic strategy for malignant gliomas.     

肿瘤切除程度及术后放、化疗对脑胶质瘤疗效影响的临床研究

目的探讨肿瘤切除程度的不同及术后不同辅助治疗方法对脑胶质瘤疗效的影响。方法对319例临床资料完整的脑胶质瘤患者进行回顾性研究，分别从肿瘤切除程度及术后辅助治疗方法两个方面探讨对低分级胶质瘤和高分级胶质瘤治疗效果的影响。根据随访结果确定1、3、5年生存率，采用Х^2检验对组间生存率差异进行比较分析。结果低分级胶质瘤患者：肿瘤全切组与未全切组1、3、5年生存率差异无显著性意义；术后早期放疗组较延期放疗组1年生存率差异无显著性意义，3、5年生存率降低。其差异有显著性意义。高分级胶质瘤患者：肿瘤全切组较未全切组1、3、5年生存率高。其差异有显著性意义；术后放、化联合治疗组较单纯放疗组1、3、5年生存率高。其差异有显著性意义。结论手术治疗脑胶质瘤。对于低分级胶质瘤应在保留重要神经功能的前提下切除肿瘤，高分级胶质瘤应尽可能扩大切除；低分级胶质瘤术后应延期行放疗，以肿瘤复发或生长增快时为宜，高分级胶质瘤术后采用放、化联合治疗较单纯放疗更为有效。     

下调TTK表达改善胶质母细胞瘤裸鼠的生存预后

目的 探讨苏氨酸/酪氨酸激酶（TTK）在胶质母细胞瘤（GBM）中的表达变化及其作用。方法 计算机检索TCGA数据库,利用生物信息学技术分析GBM组织TTK的表达水平及其与病人生存预后的关系。免疫组化染色分析我院生物样本库中60例脑胶质瘤组织的TTK表达水平。体外培养U251细胞,慢病毒转染构建TTK低表达细胞系,利用Alarma blue试剂盒测定细胞增殖能力,细胞克隆形成实验检测细胞克隆形成能力,流式细胞技术检测细胞凋亡和细胞周期。将不同TTK表达水平的U251细胞接种裸鼠构建移植瘤模型,分析TTK表达水平与移植瘤模型生存期的关系。结果 生信分析结果显示,GBM组织TTK表达水平明显高于低级别胶质瘤及正常脑组织（P<0.05）,TTK低表达GBM病人的总生存期更长（P<0.05）。我院60例胶质瘤中,高级别胶质瘤TTK高表达率（69.0%,29/42）明显高于低级别胶质瘤（16.7%,3/18;P<0.05）。下调TTK表达明显抑制U251细胞增殖、促进细胞凋亡（P<0.05）。TTK低表达裸鼠移植瘤模型的生存期明显延长（P<0.05）。结论 GBM组织...     

Expression and functional activity of heat shock proteins in human glioblastoma multiforme

OBJECTIVE: To assess the expression of heat shock proteins (HSP) in glioma cells in vitro and in vivo and to examine their role in resistance to apoptosis. BACKGROUND: HSP are expressed in response to various forms of stress. Constitutive HSP expression may confer resistance to cytotoxic stimuli in human cancers. METHODS: HSP expression was assessed by immunoblot analysis in glioma cells in vitro and by immunocytochemistry in human glioblastomas in vivo. Modulation of apoptosis by hyperthermia-mediated HSP induction was examined in glioma cell lines in vitro. RESULTS: Immunoblot analysis revealed constitutive expression of HSP27, HSP72, HSP73, and HSP90 in all 12 human glioma cell lines. B-crystallin (alphaBC) was expressed in 3 of 12 cell lines. High levels of alphaBC and HSP72 correlated with drug resistance and high p53 levels in vitro. Transient hyperthermia (43 degrees C/2 hours) induced HSP27 and HSP72 expression but had no effect on the levels of alphaBC, HSP73, or HSP90. HSP induction provided no survival advantage against subsequent cytotoxic challenges, including cytotoxic cytokines and radiochemotherapy. Immunohistochemistry showed strong expression of all HSP in vivo. The comparative analysis of HSP27, alphaBC, HSP72, HSP73, and HSP90 expression in 24 paired samples of first resections and recurrences of human glioblastoma multiforme revealed no impact of HSP expression on response to adjuvant radiochemotherapy and no modulation of HSP expression by radiochemotherapy. CONCLUSIONS: High constitutive, as opposed to inducible, expression of HSP may play a role in the primary resistance of human malignant gliomas to cytotoxic radiochemotherapy. Superinduction of HSP levels by hyperthermia in vitro provided no further survival advantage.