A trip through the signaling pathways of melanoma

Many cellular signaling pathways are involved in the development of cancer. Depending on the tumor entity, the nature as well as the mode of activation can differ. Some signaling pathways frequently show changes as all tumor cells have to fulfill some basic requirements such as independence from growth factors or insensitivity against apoptosis. In this review, the possibilities of a tumor to manipulate signaling pathways to reach these goals are exemplified based on an archetypical melanoma cell. In addition, new therapeutic options based on the knowledge of signaling pathways will be discussed.     

顺铂聚乳酸微球的药物释放特性及肝动脉栓塞研究

对顺铂聚乳酸微球进行了体外药物释放和家犬肝动脉栓塞研究。该微球粒径范围为50～200μm,平均粒径为115.76±35.94μm,顺铂含量为37.16%(W/W);体外药物释放机制符合Higuchi方程;肝动脉栓塞后8h,肝组织顺铂浓度高达21.55±12.18μg/g,明显高于肝动脉灌注顺铂组:3.16±0.09μg/g(P<0.05);肝动脉栓塞组的顺铂血浓峰值、各取血点浓度及曲线下面积AUC皆低于肝动脉灌注顺铂组。可望达到提高栓塞部位的药物疗效,降低全身毒副反应的作用。     

Expression of β-catenin in normal breast tissue and breast carcinoma: a comparative study with epithelial cadherin and α-catenin

Expression of β-catenin was investigated in normal breast tissue and 66 breast carcinomas in conjunction with expression of epithelial cadherin (E-CD) and α-catenin. In normal mammary ducts and acini, intense β-catenin immunoreactivity was present at the basolateral surfaces of luminal epithelium and weak immunoreactivity was observed at the lateral borders of myoepithelial cells. No β-catenin was revealed at the myoepithelial basal surface. The intercellular expression of β-catenin, as well as of E-CD and α-catenin, was also observed in carcinoma tissues with varying staining intensity. Almost all of 10 intraductal carcinomas and approximately 70% of 41 invasive ductal carcinomas expressed the three molecules at the same level as in normal glands, whereas approximately 80% of 13 invasive lobular carcinomas showed severe deficiency of them. Two lobular carcinomas in situ showed complete absence of all of the proteins. Some of these findings were confirmed biochemically by immunoblotting analysis. In invasive ductal carcinomas, α-catenin was reduced more frequently in diffuse than in solid type tumours, whereas the level of expression of β-catenin and E-CD was unchanged between them. No correlation was present between reduced expression of the adhesion molecules and lymph node metastasis.     

Understanding how Listeria monocytogenes targets and crosses host barriers

Human listeriosis is caused by the Gram-positive bacterium Listeria monocytogenes. In humans, this pathogen has the ability to cross the intestinal, placental and blood-brain barriers, leading to gastroenteritis, maternofetal infections and meningoencephalitis, respectively. The entry of L. monocytogenes into cultured human epithelial cells is mediated by the interaction of an L. monocytogenes surface protein, internalin, with its human receptor, E-cadherin. The internalin-E-cadherin interaction is species-specific, and relies on the nature of a single amino-acid in the E-cadherin molecule, which is proline in permissive species such as humans, and glutamic acid in non-permissive species such as the mouse. In a transgenic mouse model that expresses human E-cadherin in enterocytes, internalin allows L. monocytogenes to cross the intestinal barrier. Epidemiological evidence also supports a role for internalin in human listeriosis, not only for crossing the intestinal barrier, but also for targeting and crossing the placental and blood-brain barriers. Consistent with these epidemiological data, infection with L. monocytogenes of trophoblastic cell lines, primary trophoblast cultures and human placental villous explants demonstrates that bacterial invasion of the syncytiotrophoblast barrier is mediated by the internalin-E-cadherin interaction, leading to histopathological lesions that mimic those seen in the placentas of women with listeriosis. Thus, the internalin-E-cadherin interaction that plays a key role in the crossing of the intestinal barrier in humans is also exploited by L. monocytogenes to target and cross the placental barrier. Further investigations are currently focusing on the molecular mechanisms by which L. monocytogenes targets and crosses the blood-brain barrier.     

病毒性脑炎患者S-100b蛋白浓度与临床的相关性

目的 观察病毒性脑炎急性和恢复期患者血液和脑脊液的S-100b蛋白浓度变化，探讨其与异常脑电图和影像学低密度灶体积等方面的相关性。方法 42例病毒性脑炎住院患者为观察组，25例与观察组相匹配的阑尾或胆囊摘除手术病人以及健康体检者为对照组，采用双抗体夹心ELISA法，检测其血液及脑脊液100b蛋白浓度；并应用SPSS10．0统计软件包进行统计学分析。结果病毒性脑炎急性期患者血液和脑脊液S-100b蛋白显著高于恢复期患者和对照组（P〈0．01）；血液和脑脊液S-100b蛋白浓度与低密度灶体积均呈显著正相关（rCSF=0．756，P〈0．01；r血液=0．685，P〈0．01）；轻度、中度及重度异常脑电图患者脑脊液S-100b蛋白浓度均高于血液（P〈0．01）；重度、中度异常脑电图患者血液及脑脊液S-100b蛋白浓度均高于轻度（P〈0．01）。结论脑脊液或血液中的S-100b蛋白浓度反映了神经胶质细胞的损害程度，也是脑组织破坏后较合适的生化标记物，对监测病毒性脑炎患者的病情变化和疗效观察具有重要价值。     

sVE‐cadherin and sCD146 serum levels in patients with multiple myeloma

The role of angiogenesis in multiple myeloma (MM) pathogenesis is well established. Angiogenesis is linked to the functional state of endothelial junctions that are modulated by the growth and activation of endothelial cells. CD146 and vascular endothelial‐cadherin (VE‐cadherin) are cell adhesion molecules localized at the endothelial junction. The aim of the study was to assess sVE‐cadherin and sCD146 serum levels in MM patients. Forty‐six untreated patients with MM were included in this study. In addition, 23 of 46 patients were analyzed again in partial remission after initial chemotherapy. Twenty‐two samples from healthy volunteers were evaluated as the control. There was no significant difference in sCD146 level between MM patients and the control (511 ± 177.2 vs. 460.9 ± 156.9 ng/ml respectively). In untreated MM patients, sVE‐cadherin level was significantly higher than in the control (1.36 ± 0.55 vs. 0.63 ± 0.56 ng/ml respectively; P < 0.05). In untreated MM patients, sVE‐cadherin level was significantly higher than in MM patients in partial remission (1.36 ± 0.55 vs. 0.5 ± 0.33 respectively; P < 0.05). sVE‐cadherin but not sCD146 serum level was increased in untreated MM patients and decreases after chemotherapy in patients in partial remission. VE‐cadherin may reflect intensity of angiogenesis in MM and may be useful in prognosis of response to treatment.     

p21-ras、p53和VEGF在甲状腺乳头状癌中的表达及意义

目的　研究原癌基因Ras、抑癌基因p5 3及血管内皮生长因子 (VEGF)在甲状腺乳头状癌中的表达及相关性。方法　应用免疫组织化学S P法对 4 0例甲状腺乳头状癌中p2 1 ras、p5 3及VEGF的表达进行研究。结果　甲状腺乳头状癌中存在p2 1 ras、p5 3及VEGF的过度表达 ;VEGF的表达与p2 1 ras、p5 3的表达显著相关 (P <0 .0 5 ) ;VEGF的表达与甲状腺乳头状癌淋巴结转移显著相关 (P <0 .0 5 )。结论　p2 1 ras、p5 3、VEGF在甲状腺乳头状癌的发生发展过程中起重要作用 ;VEGF的表达与p2 1 ras、p5 3表达显著相关 ,可能受其调控。     

空管药物疗法治疗牙髓病和根尖周病疗效观察

用ＳＭＴＤ复合药物对牙髓病和根尖周病实施空管药物疗法。７８例１０３颗获得完整随访资料患牙经两年观察，９２．２％治愈率。文章介绍了治疗方法，讨论了空管药物疗法的愈合机理、优点、失败原因及其预防措施。     

Association of fibroblastoid features with the invasivephenotype in human bronchial cancer cell lines

The acquisition of a metastatic phenotype by epithelial cells implicates a series of changes altering their differentiation, their overall behavior and morphology. In the present study, we have examined the relationships between the cellular morphology, E-cadherin expression, matrix metalloproteinases expression and in vitro invasive properties in two human bronchial immortalized cell lines. The (16HBE14o-) cell line which did not show any invasive abilities in the Boyden chamber assay displayed a typical epithelial morphology in monolayer, expressed high levels of E-cadherin and synthesized neither MMP-2 and MT1-MMP nor vimentin. In contrast, the BZR cell line which was highly invasive displayed a more elongated phenotype in monolayer, did not produce E-cadherin but expressed vimentin, MMP-2 and MT1-MMP. Our data therefore suggest that the metastatic progression of broncho-pulmonary cancer cells results in a cellular dedifferentiation and the gain of some mesenchymal attributes (loss of E-cadherin and expression of vimentin) associated with enhanced degradative properties (expression of metalloproteinases).© Rapid Science 1998