Comparison of the antitumor effects of an MDM2 inhibitor, nutlin-3, in feline lymphoma cell lines with or without p53 mutation
- 作者：Hiroyuki Mochizuki ; Yuko Goto-Koshino ; Masahiko Sato ; Yasuhito Fujino ; Koichi Ohno ; Hajime Tsujimoto ; atsuji@mail.ecc.u-tokyo.ac.jp
- 关键词：Cat ; TP53 ; Murine double minute 2 ; Small molecule inhibitor
- 刊名：Veterinary Immunology and Immunopathology
- 出版年：2012
- 期刊代码：105_01652427
- 类别：abs
- 出版时间：30 June, 2012
- 卷：147
- 期：3-4
- 页码：187-194
- 文件大小：761 K
摘要
The P53 tumor suppressor protein is a multifunctional transcription factor that prevents the malignant transformation of normal cells. In human malignancies, p53 is the most frequently altered gene and is mutated in approximately 50%of all malignancies. In contrast, p53 gene mutation has been rarely detected in feline malignancies, and most feline malignancies conceivably retain the wild-type p53 (wt-p53) gene. MDM2 negatively regulates the P53 protein by inhibiting its transcriptional activity and nuclear transport and by inducing its degradation. Inhibition of P53-MDM2 interaction stabilizes P53 protein and activates P53 pathway. Nutlin-3, a small molecule that inhibits P53-MDM2 interaction, was shown to have an antitumor effect in several human cancer cells retaining the wt-p53 gene. In the present study, we evaluated and compared the antitumor effect of nutlin-3 in 5 different feline lymphoma cell lines, of which 3 harbored wt-p53, and 2, mutated p53 (mt-p53). Treatment with nutlin-3 resulted in increased amounts of P53 protein in conjunction with augmented expression of P53-target genes in 3 feline lymphoma cell lines with the wt-p53 gene, but not in 2 feline lymphoma cell lines with the mt-p53 gene. Nutlin-3 treatment also induced G1-S and/or G2-M cell cycle arrest and apoptosis in lymphoma cell lines with wt-p53. Nutlin-3 treatment induced cell cycle arrest but not apoptosis in the cell lines with mt-p53. From these results, we concluded that nutlin-3 has an antitumor effect on feline lymphoma cell lines harboring the wt-p53 gene through accumulation and activation of P53 leading to cell cycle arrest and apoptosis. The present study suggests that inhibition of P53-MDM2 interaction using nutlin-3 may be a new therapeutic strategy for treating feline lymphoma retaining the wt-p53 gene.