Conditional Gene Targeting Reveals Cell Type-Specific Roles of the Lysosomal Protease Cathepsin L in Mammary Tumor Progression
Conditional Gene Targeting Reveals Cell Type-Specific Roles of the Lysosomal Protease Cathepsin L in Mammary Tumor Progression
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DOI：
10.3390/cancers12082004
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发表时间：
2020-08-01
期刊：
影响因子：
5.2
通讯作者：
Reinheckel, Thomas
中科院分区：
文献类型：
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作者：
Parigiani, Maria Alejandra;Ketscher, Anett;Reinheckel, Thomas
背景：组织蛋白酶L（Cathepsin L，Ctsl）是一种半胱氨酸蛋白酶，主要位于内体/溶酶体细胞区室。Ctsl的高表达表明人乳腺癌预后不良。然而，负责这种协会的细胞类型特异性的Ctsl功能仍然hailey.Methods：因为constitutiveCtsl（-/-）小鼠开发一个复杂的表型，我们开发了一个条件模型，允许细胞类型特异性灭活Ctsl在乳腺上皮细胞或髓样细胞中的转基因小鼠乳腺肿瘤病毒（MMTV）-多瘤中T（PyMT）乳腺癌model.Results：Ctsl消融乳腺上皮细胞导致延迟启动和终末期癌症。后者显示大的死细胞区域。在MMTV-PyMT衍生的乳腺癌细胞中Ctsl的体外诱导缺失揭示了酸性细胞区室的扩增、细胞内氨基酸水平的改变和受损的mTOR信号传导。因此，Ctsl缺陷细胞表现出缓慢的生长速率和高凋亡易感性。相反，Ctsl缺陷的乳腺上皮细胞，选择性敲除Ctsl在骨髓细胞中没有影响原发性肿瘤，但促进肺转移formation.Conclusions：我们的细胞类型特异性的体内分析提供了强有力的证据，为癌细胞内在的，肿瘤促进作用的Ctsl在原发性乳腺癌，而转移是负调控的Ctsl表达的骨髓来源的细胞。
Background:Cathepsin L (Ctsl) is a cysteine protease mainly located within the endosomal/lysosomal cell compartment. High expression of Ctsl indicates poor prognosis in human breast cancer. However, the cell type-specific Ctsl functions responsible for this association remain elusive.Methods:Because constitutiveCtsl(-/-)mice develop a complex phenotype, we developed a conditional model allowing for cell type-specific inactivation of Ctsl in mammary epithelium or myeloid cells in the transgenic mouse mammary tumor virus (MMTV)-polyoma middle T (PyMT) breast cancer model.Results:Ctsl ablation in mammary epithelial cells resulted in delayed initiation and end-stage of cancers. The latter displayed large dead cell areas. Inducible in vitro deletion of Ctsl in MMTV-PyMT-derived breast cancer cells revealed expansion of the acidic cell compartment, alteration of intracellular amino acid levels, and impaired mTOR signaling. In consequence, Ctsl-deficient cells exhibited slow growth rates and high apoptosis susceptibility. In contrast to Ctsl-deficient mammary epithelium, selective knockout of Ctsl in myeloid cells had no effects on primary tumors, but promoted lung metastasis formation.Conclusions:Our cell type-specific in vivo analysis provides strong evidence for a cancer cell-intrinsic, tumor-promoting role of Ctsl in primary breast cancer, whereas metastasis is negatively regulated by Ctsl expressed by bone marrow-derived cells.