缺血缺氧对黑色素瘤局部浸润的相关分子机制影响的初步研究

Hypoxic microenvironment influence on VM formation and tumor-related protein expression in melanoma

目的:研究缺血缺氧环境下肿瘤生长、血液供应模式及浸润转移相关蛋白表达的变化。方法:建立小鼠缺血后肢黑色素瘤移植瘤模型,观察缺血环境下的肿瘤生长情况,计数各种血液供应模式,免疫组化染色检测HIF-1α、MMP-2、MMP-9及VEGF等在正常和缺氧环境中肿瘤细胞表达。结果:肿瘤生长早期,缺血组的肿瘤生长速度比对照组慢(t=0.858,P=0.039),但最终两组肿瘤的平均体积比较差异无统计学意义(P=0.431);缺血组瘤组织内的血管生成拟态(VM)多于对照组(P=0.037),而内皮依赖性血管的差异无统计学意义;HIF-1α、MMP-2、MMP-9和VEGF也在缺血组瘤细胞内高表达(P分别为0.036,0.015,0.008和0.019);缺血组内血管生成拟态数量和肿瘤体积与HIF-1α水平呈正相关(r=0.472,P=0.015;r=0.391,P=0.050)。结论:在缺氧环境中,黑色素瘤细胞能够通过HIF-1α上调MMP-2、MMP-9及VEGF等蛋白表达,肿瘤细胞更富有侵袭性,同时促进肿瘤血管生成拟态的形成。

OBJECTIVE： To study the molecular mechansin of hypoxic which can enhance tumor cell invasion and metastasis. METHODS： Mouse melanoma B16 cells were inoculated into mouse ischemic limbs and non-ischemic controls and the engrafted melanomas were subsequently observed respectively. Vasculogenic mimicry in melanoma cells of the two groups was counted and the expressions of HIF-1α, MMP-2, MMP-9 and VEGF were assessed by the immunohistochemical staining. Formalin-fixed, paraffin-embedded tissues were used in the immunohistochemical staining. RESULTS： In the early stage of engrafted melanoma growth, the sizes of melanomas in ischemic limbs increased more slowly than in the controls（t=0. 858, P=0. 039）. However, later there was no obvious difference in their sizes（P=0. 431）. The number of vasculogenic mimicry in melanoma of the ischemic group was more than that in the controls（P=0. 037）. Similarly, the expressions of HIF-1α, MMP-2, MMP-9 and VEGF were higher in the ischemic group than in the controls （P=0. 036, 0. 015, 0. 008 and 0. 019 respectively）. There was a positive correlation between HIF-1α expression and vasculogenic mimicry number in the ischemic group （r=0.472,0.391,P=0.015, 0.050）. CONCLUSIONS： Melanoma cells in a hypoxic microenvironment improve HIF-1α expression to upregulate the expressions of MMP-2, MMP-9 and VEGF, which enhance the invasion ability of melanoma cells to grow and metastasize as well as prompt the formation of vasculogenic mimicry to acquire an adequate blood supply.