Drubin David A, Clawson Gary A
Departments of Pathology and Biochemistry and Molecular Biology, The Jake Gittlen Cancer Research Institute, H059, Hershey Medical Center, The Pennsylvania State University, 500 University Drive, Hershey, PA 17033, USA.
Cancer Lett. 2004 Sep 15;213(1):39-48. doi: 10.1016/j.canlet.2004.03.045.
In this study, we utilized an in vitro model of spontaneous transformation/progression, an SV40 large T antigen-immortalized rat hepatocyte cell line (designated CWSV14) that is very weakly tumorigenic at low-passage, but acquires a transformed phenotype upon extended passage in cell culture. Here we show that this mid-passage transformation is accompanied by development of aneuploidy and disorganization of the actin cytoskeleton, concomitant with a large increase in a chymotrypsin-like nuclear protease activity which we have previously implicated in chemical transformation of fibroblasts and ras-transformation of hepatocytes. Passage of the CWSV14 cells with AAPF(cmk), a relatively selective inhibitor of the nuclear protease activity, abrogates the acquisition of the transformed phenotype and prevents the changes in the actin cytoskeleton. We hypothesize that the nuclear protease may play a role in initiating development of genomic instability, paralleling the archetypical role of proteases in paradigms such as the SOS-type responses in bacteria and yeast.
在本研究中，我们利用了一种自发转化/进展的体外模型，即一种SV40大T抗原永生化大鼠肝细胞系（命名为CWSV14），该细胞系在低传代时致瘤性非常弱，但在细胞培养中长时间传代后会获得转化表型。在此我们表明，这种中期传代转化伴随着非整倍体的出现和肌动蛋白细胞骨架的紊乱，同时一种类胰凝乳蛋白酶样核蛋白酶活性大幅增加，我们之前已将其与成纤维细胞的化学转化和肝细胞的ras转化联系起来。用AAPF(cmk)（一种相对选择性的核蛋白酶活性抑制剂）传代CWSV14细胞，可消除转化表型的获得，并防止肌动蛋白细胞骨架的变化。我们推测，核蛋白酶可能在引发基因组不稳定的过程中发挥作用，这类似于蛋白酶在细菌和酵母的SOS型反应等范例中的典型作用。
