title: Nocodazole-induced p53-dependent c-Jun N-terminal kinase activation reduces apoptosis in human colon carcinoma HCT116 cells.
abstract: Microtubule-interfering agents are widely used in cancer chemotherapy, and prognostic results vary significantly from tumor to tumor, depending on the p53 status. In preliminary experiments, we compared the expression and phosphorylation profiles of more than 100 protein kinases and protein phosphatases in human colorectal carcinoma cell line HCT116 between p53+/+ and p53-/- cells in response to short term nocodazole treatment through application of Kinetworks immunoblotting screens. Among the proteins tracked, the regulation of the phosphorylation of c-Jun N-terminal kinase (JNK)1/2 at Thr-183/Tyr-185 was the major difference between p53+/+ and p53-/- cells. With the loss of the p53 gene, the levels of phosphorylation of Ser-63 of c-Jun and Thr-183/Tyr-185 of JNK1/2 in p53-/- cells did not increase as markedly as in p53+/+ cells in response to a 1-h treatment with nocodazole or other microtubule-disrupting drugs such as vinblastine and colchicine. Similar observations were also made in MCF-7 and A549 tumor cells, which were rendered p53-deficient by E6 oncoprotein expression. However, arsenate-induced JNK activation in p53-/- cells was preserved. Inhibition of p53 expression by its antisense oligonucleotide also attenuated nocodazole-induced JNK activation in p53+/+ cells. Surprisingly, cotransfection of p53+/+ cells with dominant negative mutants of JNK isoforms and treatment of p53+/+ cells with the JNK inhibitor SP600125 actually further enhanced apoptosis in p53+/+ cells by up to 2-fold in response to nocodazole. These findings indicate that inhibition of p53-mediated JNK1/2 activity in certain tumor cells could serve to enhance the apoptosis-inducing actions of cancer chemotherapeutic agents that disrupt mitotic spindle function.
authors.affiliation: Department of Medicine and the Biomedical Research Centre, University of British Columbia, Vancouver, Canada.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Shi
authors.forename: Qian-Jin
authors.initials: QJ
authors.lastname: Zhang
authors.forename: Maggie
authors.initials: M
authors.lastname: Hampong
authors.forename: Harry
authors.initials: H
authors.lastname: Paddon
authors.forename: Dewi
authors.initials: D
authors.lastname: Wahyuningsih
authors.forename: Steven
authors.initials: S
authors.lastname: Pelech
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D017209:Apoptosis; D001149:Arsenates / Q000494:pharmacology; D015153:Blotting, Western; D003078:Colchicine / Q000494:pharmacology; D003110:Colonic Neoplasms; D003600:Cytosol / Q000378:metabolism; D053938:DNA Fragmentation; D004789:Enzyme Activation; D005434:Flow Cytometry; D016158:Genes, p53; D006074:Gout Suppressants / Q000494:pharmacology; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases; D007700:Kinetics; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D015739:Nocodazole / Q000494:pharmacology*; D009841:Oligonucleotides / Q000494:pharmacology; D010766:Phosphorylation; D010957:Plasmids / Q000378:metabolism; D017434:Protein Structure, Tertiary; D015398:Signal Transduction; D013997:Time Factors; D014162:Transfection; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D014747:Vinblastine / Q000494:pharmacology
chemical_list: D000970:Antineoplastic Agents; D000972:Antineoplastic Agents, Phytogenic; D001149:Arsenates; D006074:Gout Suppressants; D009841:Oligonucleotides; D016159:Tumor Suppressor Protein p53; D014747:Vinblastine; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; C025657:arsenic acid; D015739:Nocodazole; D003078:Colchicine