Gratsa A, Rooprai H K, Rogers J P, Martin K K, Pilkington G J
Department of Neuropathology, Institute of Psychiatry, De Crespigny Park, London, U.K.
Anticancer Res. 1997 Nov-Dec;17(6B):4111-7.
Studies of developing mammalian tissues have established that certain neural cell adhesion molecules (NCAMs) may be down-regulated during the migratory phase concurrent with an increase in levels of matrix metalloproteinases. In addition, there is evidence that simple gangliosides such as GD3 are transiently present on the surface of such migratory cells. Since migration, or motility, is a prerequisite for diffuse local invasion of brain by neoplastic cells, the expression of NCAM and GD3 on brain tumour cells was studied in order to establish their possible role in the invasive process. An astrocytoma parent cell line (IPSB-18) and two morphologically distinct, cloned cell lines (clone 1 and 12) derived from it, were used in in vitro motility assays using 8 microns porosity polycarbonate filters in "Transwell" modified Boyden chambers. Immunocytochemical staining with anti-NCAM monoclonal antibodies (UJ13A and ERIC-1) and with the anti-ganglioside monoclonal antibodies LB1 (which recognises GD3) and A2B5 (which recognises a range of simple gangliosides) showed that some cells in culture from the parent line were positive for either NCAM or GD3; clone 1 was NCAM positive but GD3 negative, while clone 12 was NCAM negative but ganglioside positive. Motility assays showed that although clone 12 migrated more efficiently than either clone 1 or the parent line, this was not statistically significant. Moreover, similar assays were conducted on two further sub populations of cells which were evolved from the immunomagnetic separation of the parent cell line, IPSB-18, according to NCAM expression (i.e. NCAM positive and NCAM negative). The results indicated that the NCAM negative cells migrated more efficiently than the NCAM positive cells, in a time-dependent manner, when incubated for 4, 12 and 18 hours in Boyden chambers. These findings suggest that during the migratory phase of brain tumour invasion, NCAM expression is down-regulated whereas ganglioside expression is up-regulated.
对发育中的哺乳动物组织的研究已已研究表明，某些神经细胞黏附分子（NCAMs）可能在迁移阶段下调，同时基质金属蛋白酶水平升高。此外，有证据表明，诸如GD3之类的简单神经节苷脂短暂存在于此类迁移细胞的表面。由于迁移或运动能力是肿瘤细胞弥漫性局部侵袭脑的先决条件，因此研究了脑肿瘤细胞上NCAM和GD3的表达，以确定它们在侵袭过程中可能发挥的作用。使用“Transwell”改良博伊登小室中8微米孔隙率的聚碳酸酯滤膜，对星形细胞瘤亲本细胞系（IPSB-18）及其衍生的两个形态不同的克隆细胞系（克隆1和12）进行体外运动性测定。用抗NCAM单克隆抗体（UJ13A和ERIC-1）以及抗神经节苷脂单克隆抗体LB1（识别GD3）和A2B5（识别一系列简单神经节苷脂）进行免疫细胞化学染色，结果显示，亲本细胞系培养的一些细胞对NCAM或GD3呈阳性；克隆1对NCAM呈阳性，但对GD3呈阴性，而克隆12对NCAM呈阴性，但对神经节苷脂呈阳性。运动性测定表明，尽管克隆12的迁移效率高于克隆1或亲本细胞系，但差异无统计学意义。此外，根据NCAM表达（即NCAM阳性和NCAM阴性），对亲本细胞系IPSB-18免疫磁珠分选得到的另外两个细胞亚群进行了类似测定。结果表明，在博伊登小室中孵育4、12和18小时后，NCAM阴性细胞比NCAM阳性细胞迁移效率更高，且呈时间依赖性。这些发现表明，在脑肿瘤侵袭的迁移阶段，NCAM表达下调，而神经节苷脂表达上调。
