Progression of Chemical Induced Skin Tumors

我们已经发现，PACE4在化学致癌方案诱导的高级别小鼠皮肤鳞状细胞癌中过表达。此外，当PACE4在小鼠皮肤来源的角质形成细胞中过表达时，它能够增加细胞的侵袭性。在本提案中，我们将使用转基因小鼠模型和化学诱导的皮肤肿瘤，试图在体内证明PC有助于肿瘤的发生和发展，以及在体内PC抑制将导致皮肤肿瘤形成和/或侵袭性恶性表型的减少或缺失的假说，我们将试图证明哪种PC底物一旦在体内被激活，将对肿瘤的生长和进展过程做出重大贡献。以下三个目标将被解决：1)使用PACE4在角蛋白5启动子控制下的转基因小鼠模型(K5-PACE4小鼠)，将使用化学致癌方案来确定PACE4组织特异性过表达对不同阶段皮肤癌的影响我们预计这些转基因动物将表现出更高的致癌敏感性2)使用转基因模型，PC的抑制剂将在体内进行评估我们将通过在表皮中产生表达基于蛋白质的PC抑制剂α-1 PDX(PDX)的转基因小鼠来建立基因转移方法的可行性这些小鼠应该对化学致癌和/或肿瘤进展具有抵抗力，并且应该中和PACE4的作用。此外，我们将使用已知的PC抑制剂，如氯甲基酮，局部应用于K5-PACE4小鼠的皮肤，以评估PACE4诱导的皮肤化学致癌敏感性的逆转3)，以便确定体内癌症发生的关键PC底物，我们建议将K5-PACE4小鼠与其他表达针对皮肤的PACE4底物的转基因动物，如胰岛素样生长因子-1、转化生长因子-13和MT2-MMPs杂交。这种方法将在体内建立各自底物激活在加速皮肤肿瘤发生表现部位========================================Section End===========================================的层级

EXCEED THE SPACE PROVIDED PACE4, a proprotein convertase (PC) studied in our laboratory has a significant role in the processing of metalloproteases and other cancer-related substrates We have found that PACE4 is overexpressed in high grade murine skin squamous cell carcinomas induced by chemical carcinogenesis protocols In addition, when overexpressed in mouse skin-derived keratinocytes it is able to increase cell invasiveness In the present proposal, using transgenic mouse models and chemically-induced skin tumors, we will attempt to prove in vivo, the hypothesis that PCs contribute to tumor development and progression and that in vivo PC inhibition will result in the decrease or absence of skin tumor formation and/or aggressive malignant phenotypes In addition, we will attempt to demonstrate which of the PC substrates, once activated in vivo, will contribute significantly to the process of tumor growth and progression The following three aims are to be addressed 1) Using a transgenic mouse model in which PACE4 is under the control of the keratin 5 promoter (K5-PACE4 mice), chemical carcinogenesis protocols will be used to determine the effect of PACE4 tissue specific overexpression on different stages of skin carcinogenesis We expect that these transgenic animals will exhibit an increased susceptibility to carcinogenesis 2) Using the transgenic models, inhibitors of PCs will be evaluated in vivo We will establish the feasibility of a genetic transfer approach by generating transgenic mice expressing the protein-based PC inhibitor alpha-1 PDX (PDX) in the epidermis These mice should be resistant to chemical carcinogenesis and/or tumor progression and should neutralize the effects of PACE4 In addition, we will use known PC inhibitors such as chloromethyl ketone, applied topically to the skin of K5-PACE4 mice to evaluate the reversal of the PACE4-induced susceptibility to skin chemical carcinogenesis 3) In order to determine the critical in vivo PC substrates for cancer development, we propose to cross K5-PACE4 mice with other transgenic animals expressing PACE4 substrates targeted to the skin such as IGF-1, TGF-13 and MT2-MMP This approach will establish the in vivo hierarchy of the respective substrate activation in the acceleration of skin tumor development PERFORMANCE SITE ========================================Section End===========================================