mRNA expression of topoisomerase II in human tumors and normal tissues

The cellular levels of topoisomerase II expression were compared between 10 fresh human tumors and normal tissues to predict the selective anticancer effect of its inhibitors such as adriamycin and VP-16. Topoisomerase II expression was observed in 9 of the 10 tumor tissues (90.0 per cent), 3 of which showed extremely high levels, whereas only 5 of the normal tissues (50.0 per cent) expressed any cellular topoisomerase II and the levels were not higher than those seen in the cancer cells. Six of the 9 positive tumors showed a higher level of topoisomerase II expression than the normal tissues, while the other 3 showed the same level. It can be interpreted from these results that topoisomerase II inhibitors could be effective in cancer patients due to the greater level of this enzyme in tumor cells than in normal tissues. Thus, it is suggested that a comparative analysis of topoisomerase II expression between tumors and normal tissues may be useful for predicting the selective cytotoxicity of topoisomerase II inhibitors in clinical practice.     

Alpha-1-antitrypsin in human brain tumors

This study was undertaken to confirm the presence of alpha-1-antitrypsin (alpha 1-AT) in human brain tumors and to attempt to elucidate its significance. Seventy-seven consecutive unselected patients with various brain tumors were entered in this study. The alpha 1-AT and alpha 2-macroglobulin contents of the tumor extracts were qualitatively assessed by Ouchterlony immunodiffusion techniques. Plasminogen activator (PA) activity was assayed electrophoretically on sodium dodecyl sulfate gels. The patients were were divided into two groups according to the positivity of their tumors to alpha 1-AT. Sixty-eight percent of the tumors were positive for alpha 1-AT, and all specimens were negative for alpha 2-macroglobulin. Clinical and biological parameters obtained in all study patients failed to show statistically significant differences between the two groups with the exception of PA activity (p = 0.001), the peritumoral edema as seen on computerized tomography, and the preoperative serum fibrinogen level. These three parameters were higher in the group with specimens positive to alpha 1-AT. This study supports the hypothesis that alpha 1-AT is produced primarily by tumor cells in proportion to the regional proteolytic and inflammatory activity, and may protect the tumor cells.     

Multidrug resistance gene (MDR1) expression in human brain tumors.

Multidrug resistance for many types of cancer outside the central nervous system (CNS) has been found to be due to the overexpression of the multidrug resistance gene MDR1, of which the gene-product P-glycoprotein acts as a membrane-bound efflux pump for many anticancer drugs. To examine whether brain tumors overexpress the MDR1 gene, 25 brain-tumor specimens were subjected to Northern blot analysis: 10 gliomas, eight meningiomas, three schwannomas, one malignant lymphoma, and three tumors metastatic to the brain. Ten fresh-frozen autopsy specimens of various parts of normal brain were also analyzed. Blots were hybridized with 32P-labeled Chinese hamster complementary deoxyribonucleic acid (cDNA) and 32P-labeled human MDR1 cDNA. The MDR1 gene messenger ribonucleic acid (mRNA) was detected in two tumors using the Chinese hamster probe (one sphenoid wing meningioma and one metastatic prostate tumor) and in one CNS lymphoma using the human probe. Intact mRNA could not be extracted from the fresh-frozen autopsy specimens of normal brain. Seventeen tumors were examined for P-glycoprotein by immunohistochemical staining using murine monoclonal antibody C219: eight gliomas, eight meningiomas, and one craniopharyngioma. The neoplastic cells from two gliomas and three meningiomas and the blood vessels within six gliomas and two meningiomas stained positively for P-glycoprotein. Seven of 10 normal brain specimens stained positively for P-glycoprotein in blood vessels but no specimen demonstrated staining of parenchymal cells. This study demonstrates that the MDR1 gene can be detected in normal brain, and in malignant, benign, and metastatic lesions. P-glycoprotein can be present in tumor blood vessels even when it is not seen in neoplastic cells. Although the role of P-glycoprotein in tumor blood vessels needs to be further examined and more clearly defined, drug resistance in malignant primary brain tumors may result from characteristics not solely of neoplastic cells but also tumor vasculature.     

mRNA expression of topoisomerase II in human tumors and normal tissues.

The cellular levels of topoisomerase II expression were compared between 10 fresh human tumors and normal tissues to predict the selective anticancer effect of its inhibitors such as adriamycin and VP-16. Topoisomerase II expression was observed in 9 of the 10 tumor tissues (90.0 per cent), 3 of which showed extremely high levels, whereas only 5 of the normal tissues (50.0 per cent) expressed any cellular topoisomerase II and the levels were not higher than those seen in the cancer cells. Six of the 9 positive tumors showed a higher level of topoisomerase II expression than the normal tissues, while the other 3 showed the same level. It can be interpreted from these results that topoisomerase II inhibitors could be effective in cancer patients due to the greater level of this enzyme in tumor cells than in normal tissues. Thus, it is suggested that a comparative analysis of topoisomerase II expression between tumors and normal tissues may be useful for predicting the selective cytotoxicity of topoisomerase II inhibitors in clinical practice.     

Vitamin D receptor expression in human brain tumors.

Vitamin D receptor (VDR) has important effects not only on physiological processes related to Ca2+ metabolism but also on cell growth and differentiation. VDR is a member of the Steroid-Thyroid Receptors Superfamily (STRS). Work in our and other laboratories has shown that several other members of the STRS (androgen, estrogen, glucocorticoid, and progesterone receptors) are present in astrocytomas and glioblastomas. We now report the finding of VDR-like mRNA in human anaplastic astrocytomas and glioblastomas. VDR mRNA levels, as determined by a method, developed in our laboratory, based on the polymerase chain reaction, are significantly higher in glioblastomas compared to both low and high grade astrocytomas. We discuss the biological and clinical implications of our results.     

Consistent and selective expression of the discoidin domain receptor-1 tyrosine kinase in human brain tumors

OBJECTIVE: Few molecular targets are both consistently and selectively expressed in a majority of central nervous system (CNS) neoplasms. Receptor tyrosine kinases have been implicated in brain tumor oncogenesis. We previously isolated one such receptor, discoidin domain receptor-1 (DDR1), from high-grade pediatric brain tumors. Here, we analyze the cellular origin and distribution of DDR1 expression in human brain tumors and its expression in tumor cells relative to surrounding brain. METHODS: By use of a digoxigenin-labeled DDR1 riboprobe, we investigated the expression of DDR1 messenger ribonucleic acid in a prospective series of 30 resected human primary and metastatic brain neoplasms, nonneoplastic human brain, and mouse embryonic brain, as well as a mouse glioblastoma model, by in situ hybridization. RESULTS: All the high-grade primary brain and metastatic brain tumors showed unequivocal, intense DDR1 expression within the majority of tumor cells, whereas expression was not observed in hyperplastic tumor blood vessels, normal brain blood vessels, inflammatory cells, or in the normal brain tissue that surrounded the tumor. Receptor expression was limited to tumor cells located within solid tumor tissue. Overall, 27 of 29 resected CNS tumors exhibited tumor cell-specific DDR1 expression, whereas one specimen composed of isolated glioblastoma cells within invaded brain parenchyma showed no detectable staining for this receptor. DDR1 was also expressed preferentially in the ventricular zone (a region of highly proliferating precursor cells) of mice at embryonic Day 15.5. CONCLUSION: We found that DDR1 is consistently expressed in all high-grade brain neoplasms studied and is selective for tumor cells in the specimens analyzed. The expression of DDR1 by tumor cells of CNS neoplasms and by primitive cells of the embryonic ventricular zone suggests that DDR1 is a potentially useful marker of tumor cells within the CNS.     

Prostaglandins in human brain tumors

It has been recently observed that arachidonic acid (AA) metabolites may modulate many of the mechanisms involved in tumor growth and metastasis. In order to clarify the role played in human brain tumors, authors have determined AA metabolic profiles in 63 surgical specimen of human intracranial tumors (mostly neuroepithelial tumors and meningiomas). The five metabolites via the cyclooxygenase pathway (PGD2, PGE2, TxB2, PGF2a, 6-Keto-PGF1a) were measured by high resolution gas chromatography-mass spectrometry after "ex vivo" metabolism of endogenous AA by tumor homogenates. The overall synthesis capacity of AA metabolites widely varied among different oncotypes, and, except in two cases of dermoid cysts, was higher than in normal brain tissue. AA metabolism seems more active in neuroepithelial tumors with the highest grade of anaplasia; some changes in the percentage of each metabolite is evident when anaplastic features changed. Thromboxane B2 was the most represented and 6-Keto-PGF1a the less abundant metabolite. Meningiomas and neuroepithelial tumors showed different relative proportion of AA metabolites which have in some cases reported to positively or negatively affect tumor growth. In histological subgroups of meningiomas AA metabolites synthesis capacity did not show any statistical difference. In the six cases of brain metastasis there is a wide range of overall synthesis capacity, with predominant synthesis of thromboxane B2 and prostaglandin E2, while the percentage of prostaglandin D2, reported as antimetastatic, is very low.     

Respiratory patterns in human brain tumors

It has been recognized for some time that malignant cells have a diminished respiratory rate coupled with an excessive rate of aerobic glycolysis. Subsequent studies indicated, however, that this pattern was neither unique to malignant tumors nor an essential characteristic of all varieties of cancer. In attempting to synthesize the data on oxygen consumption of human brain tumors, it is difficult to relate activity to malignancy, and the integrity of the mitochondrial electron transport chain has not been systematically examined. In this study, oxygen consumption was measured using a whole cell mixture and subsequently with isolated mitochondria prepared by routine differential centrifugation from a variety of human brain tumors. It is clear from these data that low oxidative respiration is not uniquely characteristic of malignant tumors, but that a number of benign tumors such as meningiomas and pituitary adenomas display very low levels of oxygen consumption. Many of these tumors have normal respiration, with isolated mitochondria using substrates that enter at different points in the electron transport pathway. However, several of the tumors in this series showed defects in respiration at various points in the electron transport pathway. These data suggest that both benign and malignant brain tumors have depressed respiratory capacities secondary to either a decrease in mitochondria per cell or defects in electron transport activities.     

PARP-1及其活性产物PAR在人前列腺癌组织中的表达及意义

目的探讨多聚（腺苷二磷酸核糖）聚合酶[Poly（ADP—ribose）polymerases,PARP]亚型PARP1及其活性产物聚腺苷二磷酸核糖[Poly（ADP—ribose）,PAR]在前列腺增生和前列腺癌组织中的表达及意义。方法应用免疫组织化学SP法检测并比较PARP1和PAR在19例前列腺增生和38例前列腺癌组织中的表达,及其在高分化前列腺癌（Gleason评分≤6分）和低分化前列腺癌（Gleason评分≥9分）组织中的表达差异。结果与前列腺增生相比,PARP-1和PAR在前列腺癌组织中的表达阳性率均明显升高,差异有统计学意义（P〈0．05）;虽然在高分化与低分化前列腺癌组织中的表达阳性率无明显差异（P〉0．05）,但在低分化前列腺癌组织中的表达强阳性率明显低于高分化前列腺癌（P〈0．05）。结论PARP-1和PAR存前列腺癌组织的表达明显增加,为前列腺癌的诊断提供了参考,其与前列腺癌进展的相关性有待进一步研究。     

MUC1 expression in human prostate cancer cell lines and primary tumors

MUC1 expression was evaluated in normal prostate epithelial cells (PrEC), and prostate cancer cell lines in response to dihydrotestosterone (DHT), interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) treatment. Expression of MUC1 core protein was stimulated in PrEC and PC-3 cells after cytokine treatment, but was highly and constitutively expressed by DU-145 cells. MUC1 was not expressed by LNCaP, C4-2 or C4-2B cells under any condition. DHT alone or in combination with cytokines had no effect on MUC1 expression in any cell line tested. Using antibodies capable of detecting all isoforms of MUC1 core protein independent of their glycosylation state, immunohistochemical staining of tissue microarrays containing both nontumor and tumor tissue revealed that only 17% of tumor tissues and 41% of nontumor tissues stained positively for MUC1. Staining patterns in tumor tissue varied from focal apical staining to diffuse cytoplasmic staining. Neither the presence of MUC1 core protein nor its subcellular distribution correlated with Gleason grade. These data indicate that MUC1 is a poor marker of prostate cancer progression. Furthermore, IFN-gamma and TNF-alpha strongly induce MUC1 expression in both normal prostate epithelia and certain prostate tumor cell lines and may exacerbate pathologies associated with MUC1-positive prostate cancers.     

Zymographic characteristics of soluble and bound esterases in nervous tissues and brain tumors

The Authors describe zymographic characteristics of non specific esterases in human and rat brain and in tumors of the nervous system. Bound and soluble esterases were evidenced using substrate and inhibitor systems in association with detergent extraction. In normal nervous tissues the results confirmed previous observations on the identity of the gray and white matter esterases, except for minor quantitative differences. In brain tumors some peculiar pattern was particularly useful for biological interpretation of tissue differentiation and cell metabolism. The Authors show that the use of Triton X-100 extraction associated with suitable effectors allows a more correct classification of non specific esterases.     

CatSper基因家族在人和小鼠组织中的表达特征

目的研究CatSper基因家族在人和小鼠组织中的分布特点。方法将不同发育阶段的小鼠睾丸组织cDNA与Affymetrix全基因组芯片探针进行杂交,筛选出差异表达基因CatSper基因家族。RT—PCR验证差异表达基因在不同发育阶段的小鼠睾丸组织的表达特征,及其在人和小鼠不同组织中的分布。结果基因芯片分析发现CatSper1、CatSper2和CatSper3在小鼠睾丸的表达呈阶段特异性。RT-PCR结果表明该基因家族在睾丸的表达丰度明显高于其它组织;CatSper1和CatSper4在人体睾丸组织中特异性表达。结论CatSper基因家族在人和小鼠中呈现睾丸特异性表达或高表达,可能在精子发生中发挥重要功能。     

DOG1蛋白在胃肠道间质瘤中的表达及其意义

目的 检测胃肠道间质瘤(GIST)组织中DOG1蛋白表达情况,评价DOG1蛋白对GIST诊断的价值.方法 收集北京大学人民医院1987年1月至2008年9月连续且临床病理资料完整的137例GIST肿瘤组织及73例非GIST间叶源性肿瘤组织,采用免疫组织化学染色法检测DOG1蛋白表达情况,并分析其与GIST临床病理指标的关系.结果 (1)本组中80.3%(110/137)的GIST表达DOG1蛋白,27.3%(3/11)的CD117阴性GIST表达DOG1蛋白,1.3%(1/73)的非GIST间叶源性肿痛表达DOG1蛋白;(2)GIST肿瘤组织中DOG1蛋白表达情况与肿瘤发生部位、细胞丰富程度、细胞核异形性及Fletcher危险程度分级有关(P＜0.05).DOG1阴性组和阳性组患者术后1、3、5年总生存率分别为81.3%、74.5%、74.5%和98.5%、85.9%及83.2%,P=0.344.结论 在胃肠道间叶源性肿瘤中,DOG1是GIST敏感且特异性的诊断标志物;DOG1蛋白表达状况与GIST患者的预后无关.     

Macrophages in experimental and human brain tumors. Part 2: studies of the macrophage content of human brain tumors.

The authors have analyzed 47 tumors of the central nervous system (11 glioblastomas, nine meningiomas, three medulloblastomas, 12 assorted primary neural tumors, and 12 brain metastases) for their content of macrophages. Cell suspensions were prepared by enzymatic digestion and macrophages were quantitated by IgGEAC rosette formation. Adsorption of sensitized indicator cells (EA) to sections of tumor was used as a measure to determine the distribution of IgGFc receptor-positive cells within the tumors and to serve as a control for selective release of IgGFc receptor-positive cells by enzyme digestion. The 11 glioblastomas had a mean macrophage content of 45% (range: 8% to 78%), the nine meningiomas had a mean of 44% (range: 5% to 81%), the three medulloblastomas a mean of 6% (range 2% to 15%), and the metastatic tumors a mean of 24% (range: 4% to 70%). Adsorption of EA demonstrated that IgGFc receptor-positive cells were distributed throughout the tumor mass, although different types of patterns were observed. There was an excellent correlation between the percent of IgGEAC positive cells in suspensions and the extent of EA adsorption to the tumor sections. Compared to systemic neoplasms, most nervous system tumors have a high macrophage content. It is possible that the high macrophage content of brain tumors is related to their immunogenicity, and may be a partial explanation for tha rarity of brain-tumor metastases.     

Inverse correlation of TRF1 expression and cell proliferation in human primary intracranial tumors

BACKGROUND: The telomeric-repeat binding factor (TRF1) participates in a physiological homeostatic mechanism controlling cellular proliferative potential. TRF1 is involved in a negative feedback mechanism that allows telomere shortening by inhibiting the activity of telomerase. Down-regulation of TRF1 expression results in telomere elongation and may be involved in cell immortalization. The goal of the present study was to determine whether routine immunohistochemical (IHC) techniques can characterize TRF1 expression in different human brain tumor specimens and whether it correlates with other indices of brain tumor's proliferative potential. METHODS: A cohort of 20 flash-frozen surgical specimens [14 meningiomas and 6 anaplastic astrocytomas (AA)] were evaluated for TRF1 expression. Results of parallel investigations of tumor's proliferative indices as assessed by Ki67 labeling index (LI) determinations were cross-correlated with TRF1 expression results and histotype. RESULTS: We demonstrated variable levels of TRF1 expression in 12 out of 14 (87.5%) meningioma samples. By contrast, we detected no expression of TRF1 in tissue samples from AA (p=0.008). The Ki67 LI was higher in AA than in meningioma samples (15.21+/-9.34 vs 26.6+/-13.89, p=0.044). Statistical analysis revealed a significant inverse correlation between TRF1 expression, histotype, and LI (c2=14.1; p=0.0008). CONCLUSIONS: We demonstrated for the first time that routine IHC techniques are capable to identifying TRF1 expression in intracranial tumors. The results suggest that TRF1 is heterogeneously expressed in meningiomas, and absent in AA. The TRF1 status in intracranial tumors might be of prognostic value and possibly represent a potential application for biologically targeted therapeutic strategies.