Kong L, Korthuis R J
Department of Physiology, Louisiana State University Medical Center, School of Medicine in Shreveport 71130-3932, USA.
Clin Exp Metastasis. 1997 Jul;15(4):426-31. doi: 10.1023/a:1018406422727.
An isolated perfused vessel model was used to examine the mechanisms underlying the adhesive interactions between circulating tumor cells and subendothelial matrix in denuded arterioles. Arterioles ranging from 70 to 100 microm in diameter were isolated from rat mesentery, transferred to an isolated vessel chamber, cannulated on both ends with glass micropipettes, and perfused with media containing 10(6) hamster melanoma (RPMI 1856) cells/ml. In a second group of arterioles, the endothelium was denuded by running 2 ml of air through the vessel lumen. Since the tumor cells did not adhere to the vessel wall when perfused at physiologically relevant shear rates, perfusate flow was stopped and the tumor cells were allowed to settle onto the vessel wall for 20 min. After counting the number of tumor cells that settled onto the arteriolar wall, perfusate flow was re-initiated and unattached cells were washed away. The number of cells remaining adherent were counted and the percentage of adherent cells (relative to the total number of cells that settled on to the vessel wall during the period of no-flow) were calculated and compared among different groups. We observed that tumor cells are much more adhesive to denuded arterioles than to intact arterioles. To determine the mechanisms responsible for the adhesive interactions that become established and stabilized during the period of flow reduction, denuded arterioles were treated with fibronectin antiserum or Arg-Gly-Asp (RGD) peptides. Both treatments significantly reduced tumor cell adhesion to denuded arterioles. In subsequent studies, melanoma cells were treated with a transglutaminase inhibitor, monodansylcadaverine (MDC), which reduced the ability of adherent tumor cells to withstand the anti-adhesive effects of a subsequent increase in perfusate flow rate after the period of no-flow. Our data suggest that tumor cells adhere to fibronectin in the subendothelial matrix in denuded arterioles by an RGD-dependent mechanism. Moreover, our observations are consistent with the concept that a transglutaminase-catalysed reaction acts to stabilize the adhesive interactions between subendothelial matrix components and melanoma cells during the period of flow stasis such that the cells are able to withstand subsequent substantial increases in wall shear rate and remain adherent.
采用离体灌注血管模型，研究循环肿瘤细胞与剥脱小动脉内皮下基质之间黏附相互作用的潜在机制。从大鼠肠系膜分离出直径为70至100微米的小动脉，转移至离体血管腔室，两端用玻璃微量移液器插管，并用含有每毫升10⁶个仓鼠黑色素瘤（RPMI 1856）细胞的培养基灌注。在另一组小动脉中，通过向血管腔内注入2毫升空气来剥脱内皮。由于在生理相关剪切速率下灌注时肿瘤细胞不黏附于血管壁，因此停止灌注液流动，使肿瘤细胞在血管壁上沉降20分钟。在计数沉降到小动脉壁上的肿瘤细胞数量后，重新启动灌注液流动并冲走未黏附的细胞。计数剩余黏附细胞的数量，并计算黏附细胞的百分比（相对于无流动期间沉降到血管壁上的细胞总数），并在不同组之间进行比较。我们观察到，肿瘤细胞对剥脱小动脉的黏附性比对完整小动脉的黏附性强得多。为了确定在血流减少期间建立并稳定的黏附相互作用的机制，用纤连蛋白抗血清或精氨酸 - 甘氨酸 - 天冬氨酸（RGD）肽处理剥脱小动脉。两种处理均显著降低了肿瘤细胞对剥脱小动脉的黏附。在随后的研究中，用转谷氨酰胺酶抑制剂单丹磺酰尸胺（MDC）处理黑色素瘤细胞，这降低了黏附肿瘤细胞在无流动期后承受灌注液流速随后增加的抗黏附作用的能力。我们的数据表明，肿瘤细胞通过RGD依赖性机制黏附于剥脱小动脉内皮下基质中的纤连蛋白。此外，我们的观察结果与以下概念一致，即在血流停滞期间，转谷氨酰胺酶催化的反应起到稳定内皮下基质成分与黑色素瘤细胞之间的黏附相互作用的作用，使得细胞能够承受随后壁剪切速率的大幅增加并保持黏附。
