Chen J, Willingham T, Shuford M, Bruce D, Rushing E, Smith Y, Nisen P D
Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas 75235-9063, USA.
Oncogene. 1996 Oct 3;13(7):1395-403.
p21WAF1/CIP1 is a downstream effector of the p53 tumor suppressor gene and a universal cyclin-dependent kinase (CDK) inhibitor. To determine the ability of p21WAF1/CIP1 to function as a tumor suppressor, we constructed a replication-defective adenovirus vector containing p21WAF1/CIP1 (Adp21WAF1/CIP1) to effect ectopic overexpression in a p53-defective human astrocytoma cell line, U-373MG. We observed a marked decrease in CDC2 and CDK2 kinase activity associated with a corresponding decrease in the amount of CDC2 but not CDK2 protein; a decreased growth potential of Adp21WAF1/CIP1-infected cells demonstrated by diminished [3H]thymidine incorporation, increased cell doubling time and G1-arrested cell cycle; an association between Adp21WAF1/CIP1-infected cells and inhibition of aneuploid cell accumulation; and an alteration of the malignant phenotype of cells was evidenced by the loss of anchorage-independent growth in soft agar and the failure to induce tumorigenesis in both peripheral and intracerebral xenograft models, including the prevention of tumor formation Adp21WAF1/CIP1 infection 2 days post tumor cell implantation. Adp21WAF1/CIP1. Adp21WAF1/CIP1 appears to be a strong candidate for gene therapy studies based on these studies indicating that Adp21WAF1/CIP1 inhibits proliferation, tumorigenicity and aneuploidy in human brain tumor cells.
p21WAF1/CIP1是p53肿瘤抑制基因的下游效应分子，也是一种通用的细胞周期蛋白依赖性激酶（CDK）抑制剂。为了确定p21WAF1/CIP1作为肿瘤抑制因子的功能，我们构建了一种含有p21WAF1/CIP1的复制缺陷型腺病毒载体（Adp21WAF1/CIP1），以在p53缺陷的人星形细胞瘤细胞系U-373MG中实现异位过表达。我们观察到CDC2和CDK2激酶活性显著降低，同时CDC2蛋白量相应减少，但CDK2蛋白量未减少；Adp21WAF1/CIP1感染的细胞生长潜力降低，表现为[3H]胸苷掺入减少、细胞倍增时间延长和细胞周期G1期阻滞；Adp21WAF1/CIP1感染的细胞与非整倍体细胞积累的抑制之间存在关联；细胞恶性表型的改变表现为在软琼脂中失去不依赖贴壁生长的能力，并且在周边和脑内异种移植模型中均未能诱导肿瘤发生，包括在肿瘤细胞植入后2天Adp21WAF1/CIP1感染可预防肿瘤形成。基于这些表明Adp21WAF1/CIP1抑制人脑肿瘤细胞增殖、致瘤性和非整倍性的研究，Adp21WAF1/CIP1似乎是基因治疗研究的有力候选者。
