缺氧条件下胶质瘤U251细胞培养上清液对血管内皮细胞形成管样结构的影响

目的探讨缺氧条件下胶质瘤细胞培养上清液对血管生成的影响及其与尿激酶型纤溶酶原激活物（uPA）的关系。方法在常氧、缺氧条件下对人胶质瘤U251细胞进行培养,随后取其上清液作为内皮细胞ECV304的条件培养液,并分别加入uPA及其受体（uPAR）、组织型纤溶酶原激活物（tPA）的单克隆抗体、αvβ3和αvβ5整联蛋白特异性阻滞剂,观察内皮细胞管样结构形成变化;免疫细胞化学法检测ECV304中uPA、uPAR、NF—KB的表达。结果缺氧组ECV304形成管样结构数量较常氧组增加（P〈0．05）,且随上清液浓度增加差异更明显;uPA、uPAR单克隆抗体可抑制此促进作用,而tPA抗体、αvβ3和αvβ5则无此作用;缺氧培养U251的上清液能刺激ECV304中uPA、uPAR、NF—kB表达。结论在缺氧条件下培养胶质瘤细胞培养液的上清液对血管内皮细胞管样结构形成有促进作用,且与uPA、uPAR的表达有关,与tPA、αvβ3和αvβ5整联蛋白的关系不密切。     

Biochemical markers in oncology. Part I: molecular basis. Part II: clinical uses

The investigation of the molecular mechanisms involved in carcinogenesis and tumor progression has led to the development of numerous biochemical markers. Biochemical markers may serve for early prediction of tumor recurrence, progression and development of metastases including bone metastases and for prediction of response to therapy. Tumor antigens have been used for more than a decade and although they have shown promising clinical results, their sensitivity and specificity remain limited. A lot of knowledge on the key molecules which control cell cycle, apoptosis and angiogenesis has been acquired during recent years, but their clinical value remains uncertain. Molecular markers which are linked to malignant transformation may provide a non-surgical therapeutic approach by targeting these molecules through gene therapy or antisense molecules. Because of the complexity of the physiopathogical processes involved in tumorogenesis and metastases, we first provide a review on the molecular basis of the various tumor markers and then discuss their potential clinical utility for the major cancers. The review of the current literature indicates that at the exception of a few examples, such as the use of Her-2 to predict response of the targeted Herceptin therapy, no single marker is sensitive and specific enough to perform an accurate diagnosis, predict disease progression or response to treatment. A combination of different biochemical and imaging markers appears to be the most promising strategy to monitor patients with cancer.     

The use of a uPAR-targeted probe for photothermal cancer therapy prolongs survival in a xenograft mouse model of glioblastoma

The development of tumor-targeted probes that can efficiently reach cancerous tissue is an important focus of preclinical research. Photothermal cancer therapy (PTT) relies on light-absorbing molecules, which are directed towards tumor tissue and irradiated with an external source of light. This light is transformed into heat, causing localized hyperthermia and tumor death. The fluorescent probe indocyanine green (ICG) is already used as an imaging agent both preclinically and in clinical settings, but its use for PTT is yet to be fully exploited due to its short retention time and non-specific tumor targeting. Therefore, increasing ICG tumor uptake is necessary to improve treatment outcome. The urokinase-type plasminogen activator receptor, uPAR, is overexpressed in multiple tumor types. ICG-Glu-Glu-AE105, consisting of the uPAR-targeting peptide AE105 conjugated to ICG, has shown great potential for fluorescence-guided surgery. In this study, ICG-Glu-Glu-AE105 was evaluated as photothermal agent in a subcutaneous mouse model of human glioblastoma. We observed that the photothermal abilities of ICG-Glu-Glu-AE105 triggered high temperatures in the tumor during PTT, leading to tumor death and prolonged survival. This confirms the potential of ICG-Glu-Glu-AE105 as photothermal agent and indicates that it could be used as an add-on to the application of the probe for fluorescence-guided surgery.     

Intracranial therapy of glioblastoma with the fusion protein DTAT in immunodeficient mice

A gene splicing technique was used to create a hybrid fusion protein DTAT encoding the 390 amino acid portion of diphtheria toxin (DT(390)), a linker, and the downstream 135-amino terminal fragment portion of human urokinase plasminogen activator. DTAT was assembled to target human glioblastoma cell lines in a murine intracranial model. Previously published in vitro studies demonstrated that DTAT was highly selective and toxic to human glioblastoma cell lines in a flank tumor model. The purpose of this study was to determine the toxicity, specificity and possible therapeutic efficacy of DTAT in an intracranial model. Convection enhanced delivery of DTAT resulted in about a 16-fold increase in maximum tolerated dose. Intracranial administration of DTAT on an every-other-day basis in nude mice with established U87 MG brain tumors resulted in significant reductions in tumor volume and significantly prolonged survival (p < 0.0001). Magnetic resonance imaging proved to be a powerful tool in mice and rats for demonstrating tumor growth in a xenograft intracranial model, assessing the efficacy of DTAT in tumor volume reduction and detecting DTAT-associated intracranial toxicity and vascular damage. These results suggest that the DTAT recombinant fusion protein is highly effective in an intracranial model and DTAT might be an effective treatment for glioblastoma.     

尿激酶型纤溶酶原激活系统与子宫内膜癌

尿激酶型纤溶酶原激活剂(uPA)系统通过水解纤溶酶原转变为纤溶酶降解细胞外基质,进而使肿瘤细胞不断浸润和扩散.该系统各成分的表达在子宫内膜癌组织中含量升高.本文就该系统的组成、结构、在肿瘤转移中的作用机制及其在子宫内膜癌中的研究进展作一综述,旨在为子宫内膜癌的诊断和治疗提供新的依据.     

肝细胞癌病人血浆TF,uPA及uPAR检测的临床意义

目的 探讨肝细胞癌病人血浆TF,uPA和uPAR水平变化及临床病理意义。方法应用酶联免疫法(ELISA)检测肝细胞癌病人50例及对照组30例的血浆TF,uPA和uPAR水平,并结合临床病理资料探讨其临床意义。结果 肝细胞癌病人血浆TF,uPA及uPAR均较对照组升高,差异有显著性(P<0.05)。肝细胞癌病人血浆TF在低分化组,肿瘤较大组及合并肝硬化组显著升高(P<0.05),而在不同癌灶数目及包膜情况组间无显著差异(P>0.05)。血浆uPA水平只在合并肝硬化组升高(P<0.05),uPAR水平与以上病理指标均无关(P>0.05)。肝细胞癌病人血浆TF,uPA和uPAR水平均与侵袭转移指标有关,在有淋巴转移,肝外脏器转移及门脉癌栓组较无转移及癌栓组升高(P<0.05)。结论 肝细胞癌病人存在凝血,纤溶激活状态。血浆 TF,uPA和uPAR升高与肝细胞癌的发生及侵袭转移有关,其检测有助于早期诊断病情及判断预后。     

uPA、uPAR、PAI-1血浆含量与卵巢恶性肿瘤的相关性研究

目的：探讨尿激酶型纤溶酶原激活物（uPA）及其受体（uPAR）和抑制剂（PAI-1）血浆含量与卵巢恶性肿瘤之间的关系。方法：收集52例卵巢恶性肿瘤患者血液标本,以30例健康人作对照,用ELISA法分别检测uPA、uPAR和PAI-1的含量。结果：uPA、uPAR在卵巢恶性肿瘤各期之间均有极显著性差异（P〈0．01）,PAI-1在卵巢恶性肿瘤FIGO Ⅰ～Ⅲ期的含量逐渐升高,但在FIG0Ⅳ期时显著下降（P〈0．05）。患者组uPA、uPAR、PAI-1均较对照组升高,差异极显著（P〈0．01）。结论uPA、uPAR在卵巢恶性肿瘤患者可作为预后的判断指标,PAI-1与卵巢恶性肿瘤的分期有一定的相关性。     

Chromosomal localization of the human urokinase plasminogen activator receptor and plasminogen activator inhibitor type-2 genes: Implications in colorectal cancer

Abstract Activation of the proenzyme of urokinase (uPA) on the surface of cancer cells has been implicated in the initiation of focal proteolytic mechanisms that permit invasion and metastasis by colon cancers. The activity of uPA on the cell surface appears to be a function of the number of uPA-specific receptors (uPAR) and the extent of inhibition of uPA by plasminogen activator inhibitors (PAI). The mapping of the genes coding for uPAR, and for PAI-2, was performed to determine whether their chromosomal localization suggested their involvement in the genetic alterations associated with cancer cell DNA.
This study confirms the localization of the human urokinase plasminogen activator receptor gene to chromosome 19q and, using in situ hybridization, provides a precise localization to chromosome 19q13.2. In addition, our results confirm the previous allocation of the human plasminogen activator inhibitor-2 gene to a location 18q21.3 → 18q21.1, a location that corresponds to the commonest (>70%) somatic deletions found in colorectal carcinomas. The mapping of the uPAR and PAI-2 genes enables the elucidation of their possible involvement in the genetic alterations that determine the invasive and metastatic phenotypes in colorectal cancer.     

反义基因片段抑制人胶质瘤u251增殖和侵袭的体外研究

目的:研究反义PCNA及uPAR基因片段对胶质瘤细胞株u2 5 1体外增殖和侵袭能力的影响。方法:用脂质体介导寡核苷酸转染培养的u2 5 1胶质瘤细胞,RT PCR、原位杂交和免疫组化等方法分别检测相关基因和蛋白的表达,MTT比色法研究对胶质瘤细胞增殖能力的影响,Boyden小室模型研究对细胞侵袭能力的影响。结果:PCNA及uPAR反义寡核苷酸作用u2 5 1胶质瘤细胞后相关基因的mRNA及蛋白的表达明显减弱,细胞的体外增殖和侵袭能力明显被抑制。结论:反义PCNA及uPAR寡核苷酸片段能有效地抑制胶质瘤细胞的u2 5 1相关基因的表达,并能抑制胶质瘤细胞的体外增殖和侵袭能力。