title: DNA damage-induced expression of p53 suppresses mitotic checkpoint kinase hMps1: the lack of this suppression in p53MUT cells contributes to apoptosis.
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.
authors.affiliation: Department of Gastroenterology, University Medical Center Charité, Campus Benjamin Franklin, 12200 Berlin, Germany.
authors.forename: Mandar R
authors.initials: MR
authors.lastname: Bhonde
authors.forename: Marie-Luise
authors.initials: ML
authors.lastname: Hanski
authors.forename: Jan
authors.initials: J
authors.lastname: Budczies
authors.forename: Minh
authors.initials: M
authors.lastname: Cao
authors.forename: Bernd
authors.initials: B
authors.lastname: Gillissen
authors.forename: Dhatchana
authors.initials: D
authors.lastname: Moorthy
authors.forename: Federico
authors.initials: F
authors.lastname: Simonetta
authors.forename: Hans
authors.initials: H
authors.lastname: Scherübl
authors.forename: Matthias
authors.initials: M
authors.lastname: Truss
authors.forename: Christian
authors.initials: C
authors.lastname: Hagemeier
authors.forename: Hans-Werner
authors.initials: HW
authors.lastname: Mewes
authors.forename: Peter T
authors.initials: PT
authors.lastname: Daniel
authors.forename: Martin
authors.initials: M
authors.lastname: Zeitz
authors.forename: Christoph
authors.initials: C
authors.lastname: Hanski
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D017209:Apoptosis; D015153:Blotting, Western; D002166:Camptothecin / Q000031:analogs & derivatives / Q000494:pharmacology; D002277:Carcinoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D002453:Cell Cycle / Q000187:drug effects; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D004249:DNA Damage; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic; D045325:HCT116 Cells; D019073:HT29 Cells; D006367:HeLa Cells; D006801:Humans; D000077146:Irinotecan; D008954:Models, Biological; D009363:Neoplasm Proteins / Q000172:deficiency; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D018797:Cell Cycle Proteins; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D016159:Tumor Suppressor Protein p53; D000077146:Irinotecan; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; C075840:TTK protein, human; D002166:Camptothecin