Targeting alfa 1beta1 integrin in cancer development

描述(申请人提供)：实体肿瘤的生长高度依赖血管生成。在这个新的血管形成过程中，表达在内皮细胞上的整合素是重要的介质。抑制这些整合素的功能是目前癌症研究的方向之一。此外，癌细胞上表达的整合素参与了癌细胞在转移过程中的迁移。在拟议的研究计划中，我们将研究ct1131整合素(VLA-1)，它被认为是一种特异性的IV型胶原受体。我们将重点研究VLA-1的两种抑制剂--奥布他丁和蛇毒抑素。它们都属于去整合素家族，都是VLA-1的低分子量抑制剂(4.2 kDa)。这些去整合素的活性被定位在它们的整合素结合环中，作为活性序列KTS。在体内的鸡CAM模型和体外的试管内皮细胞形成实验中，Obtustatin显示了很强的血管抑制活性。此外，奥布他丁还能抑制同基因小鼠模型Lewis肺癌的发生。KTS去整合素的活性将进一步在小鼠黑色素瘤B16和M-3细胞系在同基因小鼠体内以及人黑色素瘤细胞系MV3、HS.939T、A-375、C32和A2058裸鼠体内诱导生长的肿瘤上进行检测。VLA-1参与这些细胞系向肺转移的作用将在体内使用同基因和裸鼠进行研究。为了解释含有去整合素的KTS的血管抑制作用的机制，我们将通过一系列的实验来研究它们对微血管内皮细胞的影响。初步数据显示，奥布他丁可诱导这些细胞发生凋亡，并抑制其增殖。根据已有报道表明VLA-1参与MAPK依赖的信号转导通路，我们将评估KTS-disIntegrins对该通路激活的影响。此外，还将提出在胶原凝胶中的径向迁移分析。体外实验模拟基底膜溶解后新生血管早期内皮细胞的运动。这两种去整合素在该模型中对EC运动的影响将被测试。Obtustatin及其天然类似物Viperisrastatin可能是设计合成或重组化合物的模型，这可能在癌症治疗中有用。总之，使用含有去整合素的KTS的工作可能有助于更好地理解VLA-1在肿瘤进展和转移中的作用，以及有助于理解VLA-1在血管生成中的作用。

DESCRIPTION (provided by applicant): The growing of solid tumors highly depends on angiogenesis. In this new vessel formation process the integrins, expressed on endothelial cells are important mediators. Inhibition of function of these integrins is currently one of the directions in cancer research. Moreover, integrins expressed on cancer cells are involved in migration of these cells during metastasis. In the proposed research plan, we will investigate ct 1131 integrin (VLA-1), which is recognized as a specific collagen IV receptor. We will focus our research on two inhibitors of VLA-1, obtustatin and viperisrastatin. Both of them belong to disintegrin family, and are low molecular mass inhibitors (4.2 kDa) of VLA-1. The activity of these disintegrins has been localized within their integrin-binding loop as an active sequence KTS. Obtustatin showed potent angiostatic activity in the chicken CAM model in vivo, and in tube EC formation assay in vitro. Moreover, obtustatin inhibited Lewis lung cancer development in syngeneic mouse model. The activity of KTS-disintegrins will be further tested on growing tumor induced by mouse melanoma B 16 and M-3 cell lines in the syngeneic mouse, and human melanoma cell lines, MV3, HS.939T, A-375, C32, and A2058 in nude mice. The participation VLA-1 in metastasis of these cell lines to the lung will be investigated in vivo using syngeneic and nude mice. To explain the mechanism of the angiostatic effect of KTS containing disintegrins, series of experiments will be performed to investigate their effect on microvascular EC. The preliminary data showed that obtustatin induced apoptosis in these cells and inhibited their proliferation. Based on the previous reports indicating involvement of VLA-1 in signal transduction pathway dependent on MAPK, the effect of KTS-disintegrins on activation of this pathway will be evaluated. Moreover, radial migration assay in collagen gel will be proposed. That in vitro assay imitates movement of EC during early stage of neovascularization after dissolution of the basement membrane. The effect of both disintegrins in EC motility in this model will be tested. Obtustatin and its naturally occurring analog viperisrastatin may be models for designing of synthetic or recombinant compounds, which may be useful in cancer therapy. In summary, the work with KTS containing disintegrins may lead to the better understanding of the involvement of VLA-1 in cancer progression and metastasis, as well as contribute to an understanding of the role of VLA-1 in angiogenesis.