探索靶向溶酶体膜通透化的抗癌药物筛选模型

The tumor microenvironment may promote tumor formation and metastasis mainly via angiogenesis induction, suppression of immune surveillance and immune response, and breeding tumor stem cells. Co-culture of tumor and various stromal cells which can mimic the tumor microenvironment has created great expectation concerning the methods of drug screening targeting the tumor microenvironment. ..Lysosomal membrane permeabilization (LMP) is defined as a perturbation of lysosomal membrane function that leads to the translocation of lysosomal hydrolases (including cathepsins) from the lysosomal lumen to the rest of the cell. Also LMP can trigger the programmed cell death. Meanwhile, targeting LMP can cover multiple targets and/or multiple signaling pathways involved in the tumorigenesis and metastasis, and therefore LMP becomes an ideal anti-tumor target. Additionally the feature that the signal of green fluorescent protein (GFP) is attenuated by acidic conditions can be utilized to indicate where and when LMP occurs...Consequently, we propose a novel drug screening model. In such a model we co-culture prostate cancer cell and bone stromal cell to mimic the microenvironment of bone metastasis in prostate cancer, and utilize the GFP-mRFP tandem fluorescent reporter tagged lysosomal membrane proteins to indicate the change of lysosomes. On the one hand we aim to construct an in vitro screening model targeting LMP and to evaluate the effect of the model; on the other hand, we expect to gain some anti-cancer natural medicine components from traditional Chinese medicine via such a model.

肿瘤微环境可以通过诱导新生血管形成、抑制免疫监视和免疫反应、孕育肿瘤干细胞等促进肿瘤发生及转移。通过肿瘤与基质细胞共培养模拟肿瘤微环境，实现靶向肿瘤微环境的药物筛选越来越受到重视。溶酶体膜通透化（Lysosomal Membrane Permeabilization, LMP）是溶酶体膜损伤引起的溶酶体内组织蛋白酶和水解酶外泄的过程，它还是启动程序化细胞死亡的标志事件。由于靶向LMP符合针对多靶点多环节抗癌药物筛选的要求，LMP可能成为一个癌症治疗理想靶点。而绿色荧光蛋白在酸性环境失去荧光的特性可能被用于指示溶酶体膜通透化。因此我们拟采用前列腺癌与骨基质细胞共培养，模拟前列腺癌骨转移的肿瘤微环境；利用串联红绿荧光蛋白标记的溶酶体膜蛋白来检测溶酶体的变化，构建靶向LMP的筛选模型。一方面评价该模型的效果，构建分子、细胞水平的高特异性体外筛选模型；另一方面期望利用该模型筛选出抗癌天然药物组分。