Initiation and characterization of keratinocyte cultures from biopsies of normal human conjunctiva

The purpose of the present study was to establish and characterize serum-free epithelial cultures of normal human conjunctiva using fresh biopsy tissue. To this end, small pieces of normal conjunctiva were biopsied from patients undergoing routine cataract surgery. Fragments of the tissue were placed in explant culture in medium containing fetal bovine serum for approximately 1 week to promote epithelial cell outgrowth. Cultures were then passaged multiple times into serum-free medium. Cultures generated in this way were at least 95% keratinocytes and exhibited a typical epithelial morphology, which was dependent on the extracellular Ca(2+)concentration. Immunocytochemical staining revealed that E-cadherin, P-cadherin, and involucrin were present in the cultures, with distributions consistent with their in vivo localization patterns. Distribution of keratins 19, 3, and 4 in conjunctival epithelial cultures were also consistent with in vivo patterns and distinctly different from patterns observed in epithelial cultures similarly generated from cornea and foreskin. Hence, conjunctival keratinocyte cultures retain some tissue-specific markers and do not revert to a generic, culture phenotype.     

Small-scale pattern formation in a cortical area of the embryonic chicken telencephalon

The parahippocampal area is a cortical region of the avian dorsomedial telencephalon. In the chicken embryo, it contains discrete clusters of cadherin-7-positive cells, which are embedded in a cadherin-7-negative matrix. In the present work, the development and spatial distribution of these clusters is studied in whole-mount specimens. The clusters form a complex, coherent pattern of patches of variable size, spacing, and staining intensity. The pattern is especially prominent and regularly spaced in the rostral part of the caudolateral parahippocampal area. Here, it consists of stripes and connecting bridges with an average periodicity of approximately 0.3 mm. This pattern vaguely resembles some animal fur patterns and the ocular dominance domain of the mammalian visual cortex. The cadherin-7-positive patches also differ from their surrounding area by their cytoarchitecture and their increased acetylcholinesterase activity, suggesting that they represent functionally specialized subregions within the parahippocampal area. During development, the patchiness is first observed between 9 and 10 days of incubation and gradually becomes more prominent until 15 days of incubation. Our results indicate that the patchy organization of cortical gray matter on a small scale of periodicity (below 1 mm), which is well studied in the mammalian neocortex, is also found in the avian telencephalon.     

Neural (N-) cadherin,a synaptic adhesion molecule,is induced in hippocampal mossy fiber axonal sprouts by seizure

Aberrant mossy fiber sprouting and synaptic reorganization are plastic responses in human temporal lobe epilepsy, and in pilocarpine-induced epilepsy in rodents. Although the morphological features of the hippocampal epileptic reaction have been well documented, the molecular mechanisms underlying these structural changes are not understood. The classic cadherins, calcium-dependent cell adhesion molecules, are known to function in development in neurite outgrowth, synapse formation, and stabilization. In pilocarpine-induced status epilepticus, the expression of N-cadherin mRNA was sharply upregulated and reached a maximum level (1- to 2.5-fold) at 1- to 4 weeks postseizure in the granule cell layer and the pyramidal cell layer of CA3. N-cadherin protein was correspondingly increased and became concentrated in the inner molecular layer of the dentate gyrus, consistent with the position of mossy fiber axonal sprouts. Moreover, N-cadherin labeling was punctate; colocalized with definitive synaptic markers, and partially localized on polysialated forms of neural cell adhesion molecule (PSA-NCAM)-positive dendrites of granule cells in the inner molecular layer. Our findings show that N-cadherin is likely to be a key factor in responsive synaptogenesis following status epilepticus, where it functions as a mediator of de novo synapse formation.     

Downregulation of expression of a novel cadherin molecule,T-cadherin,in basal cell carcinoma of the skin

T-cadherin appears to act as a tumor-suppressor factor in various cancers. Downregulation of T-cadherin is caused by a combination of allelic loss and hypermethylation of the T-cadherin promoter region and is related to cancer invasion. To elucidate the molecular mechanism of invasiveness of basal cell carcinoma of the skin, T-cadherin expression was investigated in archival pathological tissue sections made up of normal counterparts of skin and various types of basal cell carcinoma. Immunohistochemical staining showed that T-cadherin was not expressed in 38 of 51 (75%) basal cell carcinoma specimens, whereas normal counterparts of the skin appeared to express abundant T-cadherin. Loss of heterozygosity in intron 1 of the T-cadherin gene was found in four of 20 informative cases that did not express T-cadherin. Aberrant methylation of the T-cadherin promoter region also was found in six of 25 basal cell carcinomas by methylation-specific polymerase chain reaction. In contrast, no structural alternations were found in two loss of heterozygosity-positive basal cell carcinomas on sequence analysis. These findings indicated that T-cadherin expression was downregulated by a combination of allelic loss and aberrant methylation in basal cell carcinoma of the skin. Loss of T-cadherin expression might be related to the biological behavior of basal cell carcinoma. In addition, results of the present study suggested that downregulation of T-cadherin in various cancers might be related to tumor invasiveness rather than metastasis, because basal cell carcinoma of the skin principally lacks metastatic activity.     

益气活血方对肺癌细胞株上皮细胞粘附分子表达及侵袭能力的影响

目的观察益气活血中药对肺癌细胞株体外生长抑制,上皮细胞粘附分子(E-CD)表达及侵袭能力的影响。方法采用细胞计数、S-P免疫组织化学、图像分析及侵袭小室等方法,观察小细胞肺癌细胞株NC-H446姜益气活血中药、全反式维甲酸(ARTA)处理不同时间后细胞生长状况、E-CD表达及侵袭能力的影响。结果姜两干预因素下细胞生长抑制,形态改变。中药干预下,NC-H446细胞株E-CD阳性表达率由原来的12%±8%提高到34%±9%,积分光密度(IOD)由78.5±16.9增加到200.3±21.7,前后相比具有明显差异(P<0.01);穿过基质胶的细胞数分别为126.5±43.61,与对照组相比差异显著(P<0.01);与ARTA相比无明显差异。结论益气活血中药能明显抑制NC-H446细胞株的生长,能促进E-CD的正常表达,减弱肿瘤细胞的侵袭转移能力;中药姜上述作用方面可代替ARTA。     

非小细胞肺癌血管内皮生长因子和上皮型钙黏附蛋白表达的研究

目的 :研究血管内皮生长因子 (VEGF)及上皮型钙黏附蛋白 (E cadherin)在非小细胞肺癌(NSCLC)中的表达。方法 :采用免疫组化SABC法 ,对石蜡包埋的NSCLC患者标本 90例分别进行VEGF及E cadherin检测。结果 :VEGF在NSCLC中表达阳性率为 70 0 % (6 3/ 90 ) ,E cadherin的表达阳性率为 5 2 2 % (4 7/ 90 ) ;不同组织学类型、病理分级、pTNM分期、淋巴结转移的VEGF表达率差异无显著意义 ,P >0 0 5 ,VEGF与预后密切相关。E cadherin与pTNM分期、病理分级、淋巴结转移及预后有关 ;VEGF与E cadherin在NSCLC中的表达有显著相关性。结论 :VEGF与肿瘤发生密切相关 ;E cad herin缺失是判断预后的重要指标 ,可作为判断肿瘤转移的有价值的指标。NSCLC中VEGF的高表达与E cadherin表达的缺失共同促使了肿瘤的发生和转移 ,是判断预后的重要指标     

术前化疗对胃癌组织上皮钙黏附素表达的影响

目的 :揭示上皮钙黏附素 (epithelialcadherin ,E cd)在化疗后的胃癌组织及癌旁组织中表达的变化 ,探讨术前化疗的意义。方法 :以 5 FU 15mg (kg·d)对进展期胃癌患者行术前化疗 ,术中取胃癌组织及癌旁组织 ,应用免疫组织化学法 (S P法 )检测E cd在 32例化疗后标本中的表达 ,与对照组 30例进行比较。结果 :5 FU术前化疗可明显提高E cd阳性表达率 (与对照组相比P <0 0 1)而且 5 FU >3 0组与 5 FU <3 0组之间差异有显著性 (P <0 0 2 5 ) ,在癌旁组织中 5 FU >3 0组与非化疗组之间差异有显著性 (P <0 0 2 5 ) ,而E cd在不同细胞分化及病期中表达差异无显著性。结论 :5 FU术前化疗可以提高胃癌组织及癌旁组织的E cd阳性表达水平 ,术前化疗可能减弱胃癌的侵袭转移性