DNA damage-induced expression of p53 suppresses mitotic checkpoint kinase hMps1: the lack of this suppression in p53MUT cells contributes to apoptosis

Item Type:	Article
Title:	DNA damage-induced expression of p53 suppresses mitotic checkpoint kinase hMps1: the lack of this suppression in p53MUT cells contributes to apoptosis
Creators Name:	Bhonde, M.R. and Hanski, M.L. and Budczies, J. and Cao, M. and Gillissen, B. and Moorthy, D. and Simonetta, F. and Scheruebl, H. and Truss, M. and Hagemeier, C. and Mewes, H.W. and Daniel, P.T. and Zeitz, M. and Hanski, C.
Abstract:	DNA damage induced by the topoisomerase I inhibitor irinotecan (CPT-11) triggers in p53(WT) colorectal carcinoma cells a long term cell cycle arrest and in p53MUT cells a transient arrest followed by apoptosis (Magrini, R., Bhonde, M. R., Hanski, M. L., Notter, M., Scherübl, H., Boland, C. R., Zeitz, M., and Hanski, C. (2002) Int. J. Cancer 101, 23-31; Bhonde, M. R., Hanski, M. L., Notter, M., Gillissen, B. F., Daniel, P. T., Zeitz, M., and Hanski, C. (2006) Oncogene 25, 165-175). The mechanism of the p53-independent apoptosis still remains largely unclear. Here we used five p53WT and five p53MUT established colon carcinoma cell lines to identify gene expression alterations associated with apoptosis in p53MUT cells after treatment with SN-38, the irinotecan metabolite. After treatment, 16 mitosis-related genes were found to be expressed at least 2-fold stronger in the apoptosis-executing p53MUT cells than in the cell cycle-arrested p53WT cells by oligonucleotide microarray analysis. One of the genes whose strong post-treatment expression was associated with apoptosis was the mitotic checkpoint kinase hMps1 (human ortholog of the yeast monopolar spindle 1 kinase). hMps1 mRNA and protein expression were suppressed by the treatment-induced and by the exogenous adenovirus-coded p53 protein. The direct suppression of hMps1 on RNA level or inhibition of its activity by a dominant-negative hMps1 partly suppressed apoptosis. Together, these data indicate that the high expression of mitotic genes in p53MUT cells after SN-38 treatment contributes to DNA damage-induced apoptosis, whereas their suppression in p53WT cells acts as a safeguard mechanism preventing mitosis initiation and the subsequent apoptosis. hMps1 kinase is one of the mitotic checkpoint proteins whose expression after DNA damage in p53MUT cells activates the checkpoint and contributes to apoptosis.
Keywords:	Apoptosis, Biological Models, Camptothecin, Carcinoma, Cell Cycle, Cell Cycle Proteins, Colonic Neoplasms, DNA Damage, Flow Cytometry, HTC116 Cells, HT29 Cells, HeLa Cells, Messenger RNA, Neoplasm Proteins, Neoplastic Gene Expression Regulation, Phytogenic Antineoplastic Agents, Phytogenic Antineoplastic Kinases, Protein-Tyrosine Kinases, Reverse Transcriptase Polymerase Chain Reaction, Tumor Cell Line, Tumor Suppressor Protein p53, Western Blotting
Source:	Journal of Biological Chemistry
ISSN:	0021-9258
Publisher:	American Society for Biochemistry and Molecular Biology
Volume:	281
Page Range:	8675-8685
Date:	31 March 2006
Official Publication:	https://doi.org/10.1074/jbc.M511333200
PubMed:	View item in PubMed

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