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Role of the p53/p21 system in the response of human colon carcinoma cells to Doxorubicin

BACKGROUND: Colon adenocarcinomas are refractory to a number of widely used anticancer agents. Multifactorial mechanisms have been implicated in this intrinsically resistant phenotype, including deregulation of cell death pathways. In this regard, the p53 protein has a well established role in the c...

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Autores principales: Ravizza, Raffaella, Gariboldi, Marzia B, Passarelli, Laura, Monti, Elena
Formato: Texto
Lenguaje:English
Publicado: BioMed Central 2004
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC544559/
https://www.ncbi.nlm.nih.gov/pubmed/15601469
http://dx.doi.org/10.1186/1471-2407-4-92
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author Ravizza, Raffaella
Gariboldi, Marzia B
Passarelli, Laura
Monti, Elena
author_facet Ravizza, Raffaella
Gariboldi, Marzia B
Passarelli, Laura
Monti, Elena
author_sort Ravizza, Raffaella
collection PubMed
description BACKGROUND: Colon adenocarcinomas are refractory to a number of widely used anticancer agents. Multifactorial mechanisms have been implicated in this intrinsically resistant phenotype, including deregulation of cell death pathways. In this regard, the p53 protein has a well established role in the control of tumor cell response to DNA damaging agents; however, the relationship between p53-driven genes and drug sensitivity remains controversial. The present study investigates the role of the p53/p21 system in the response of human colon carcinoma cells to treatment with the cytotoxic agent doxorubicin (DOX) and the possibility to modify the therapeutic index of DOX by modulation of p53 and/or p21 protein levels. METHODS: The relationship between p53 and p21 protein levels and the cytotoxic effect of DOX was investigated, by MTT assay and western blot analysis, in HCT116 (p53-positive) and HT29 (p53-negative) colon cancer cells. We then assessed the effects of DOX in two isogenic cell lines derived from HCT116 by abrogating the expression and/or function of p53 and p21 (HCT116-E6 and HCT116 p21-/-, respectively). Finally, we evaluated the effect of pre-treatment with the piperidine nitroxide Tempol (TPL), an agent that was reported to induce p21 expression irrespective of p53 status, on the cytotoxicity of DOX in the four cell lines. Comparisons of IC50 values and apoptotic cell percentages were performed by ANOVA and Bonferroni's test for independent samples. C.I. calculations were performed by the combination Index method. RESULTS: Our results indicate that, in the colon carcinoma cell lines tested, sensitivity to DOX is associated with p21 upregulation upon drug exposure, and DOX cytotoxicity is potentiated by pre-treatment with TPL, but only in those cell lines in which p21 can be upregulated. CONCLUSIONS: p21 induction may significantly contribute to the response of colon adenocarcinomas cells to DOX treatment; and small molecules that can exploit p53-independent pathways for p21 induction, such as TPL, may find a place in chemotherapeutic protocols for the clinical management of colorectal cancer, where p53 function is often lost, due to genetic or epigenetic defects or to post-transcriptional inactivating mechanisms.
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spelling pubmed-5445592005-01-16 Role of the p53/p21 system in the response of human colon carcinoma cells to Doxorubicin Ravizza, Raffaella Gariboldi, Marzia B Passarelli, Laura Monti, Elena BMC Cancer Research Article BACKGROUND: Colon adenocarcinomas are refractory to a number of widely used anticancer agents. Multifactorial mechanisms have been implicated in this intrinsically resistant phenotype, including deregulation of cell death pathways. In this regard, the p53 protein has a well established role in the control of tumor cell response to DNA damaging agents; however, the relationship between p53-driven genes and drug sensitivity remains controversial. The present study investigates the role of the p53/p21 system in the response of human colon carcinoma cells to treatment with the cytotoxic agent doxorubicin (DOX) and the possibility to modify the therapeutic index of DOX by modulation of p53 and/or p21 protein levels. METHODS: The relationship between p53 and p21 protein levels and the cytotoxic effect of DOX was investigated, by MTT assay and western blot analysis, in HCT116 (p53-positive) and HT29 (p53-negative) colon cancer cells. We then assessed the effects of DOX in two isogenic cell lines derived from HCT116 by abrogating the expression and/or function of p53 and p21 (HCT116-E6 and HCT116 p21-/-, respectively). Finally, we evaluated the effect of pre-treatment with the piperidine nitroxide Tempol (TPL), an agent that was reported to induce p21 expression irrespective of p53 status, on the cytotoxicity of DOX in the four cell lines. Comparisons of IC50 values and apoptotic cell percentages were performed by ANOVA and Bonferroni's test for independent samples. C.I. calculations were performed by the combination Index method. RESULTS: Our results indicate that, in the colon carcinoma cell lines tested, sensitivity to DOX is associated with p21 upregulation upon drug exposure, and DOX cytotoxicity is potentiated by pre-treatment with TPL, but only in those cell lines in which p21 can be upregulated. CONCLUSIONS: p21 induction may significantly contribute to the response of colon adenocarcinomas cells to DOX treatment; and small molecules that can exploit p53-independent pathways for p21 induction, such as TPL, may find a place in chemotherapeutic protocols for the clinical management of colorectal cancer, where p53 function is often lost, due to genetic or epigenetic defects or to post-transcriptional inactivating mechanisms. BioMed Central 2004-12-15 /pmc/articles/PMC544559/ /pubmed/15601469 http://dx.doi.org/10.1186/1471-2407-4-92 Text en Copyright © 2004 Ravizza et al; licensee BioMed Central Ltd.
spellingShingle Research Article
Ravizza, Raffaella
Gariboldi, Marzia B
Passarelli, Laura
Monti, Elena
Role of the p53/p21 system in the response of human colon carcinoma cells to Doxorubicin
title Role of the p53/p21 system in the response of human colon carcinoma cells to Doxorubicin
title_full Role of the p53/p21 system in the response of human colon carcinoma cells to Doxorubicin
title_fullStr Role of the p53/p21 system in the response of human colon carcinoma cells to Doxorubicin
title_full_unstemmed Role of the p53/p21 system in the response of human colon carcinoma cells to Doxorubicin
title_short Role of the p53/p21 system in the response of human colon carcinoma cells to Doxorubicin
title_sort role of the p53/p21 system in the response of human colon carcinoma cells to doxorubicin
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC544559/
https://www.ncbi.nlm.nih.gov/pubmed/15601469
http://dx.doi.org/10.1186/1471-2407-4-92
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