Quercetin abrogates chemoresistance in melanoma cells by modulating DeltaNp73

Persistent Link:
http://hdl.handle.net/10150/610343
Title:
Quercetin abrogates chemoresistance in melanoma cells by modulating DeltaNp73
Author:
Thangasamy, Thilakavathy; Sittadjody, Sivanandane; Mitchell, Geoffrey; Mendoza, Erin; Radhakrishnan, Vijayababu; Limesand, Kirsten; Burd, Randy
Affiliation:
Department of Nutritional Sciences, University of Arizona, Tucson, AZ 85721, USA; Cancer Biology Interdisciplinary Program, University of Arizona, Tucson, AZ 85721, USA; Arizona Cancer Center, University of Arizona, Tucson, AZ 85721, USA
Issue Date:
2010
Publisher:
BioMed Central
Citation:
Thangasamy et al. BMC Cancer 2010, 10:282 http://www.biomedcentral.com/1471-2407/10/282
Journal:
BMC Cancer
Rights:
© 2010 Thangasamy et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0)
Collection Information:
This item is part of the UA Faculty Publications collection. For more information this item or other items in the UA Campus Repository, contact the University of Arizona Libraries at repository@u.library.arizona.edu.
Abstract:
BACKGROUND:The alkylating agent Dacarbazine (DTIC) has been used in the treatment of melanoma for decades, but when used as a monotherapy for cancer only moderate response rates are achieved. Recently, the clinical use of Temozolomide (TMZ) has become the more commonly used analog of DTIC-related oral agents because of its greater bioavailability and ability to cross the blood brain barrier. The response rates achieved by TMZ are also unsatisfactory, so there is great interest in identifying compounds that could be used in combination therapy. We have previously demonstrated that the bioflavonoid quercetin (Qct) promoted a p53-mediated response and sensitized melanoma to DTIC. Here we demonstrate that Qct also sensitizes cells to TMZ and propose a mechanism that involves the modulation of a truncated p53 family member, DeltaNp73.METHODS:DB-1 melanoma (p53 wildtype), and SK Mel 28 (p53 mutant) cell lines were treated with TMZ (400 muM) for 48 hrs followed by Qct (75 muM) for 24 hrs. Cell death was determined by Annexin V-FITC staining and immunocytochemical analysis was carried out to determine protein translocation.RESULTS:After treatment with TMZ, DB-1 cells demonstrated increased phosphorylation of Ataxia telangiectasia mutated (ATM) and p53. However, the cells were resistant to TMZ-induced apoptosis and the resistance was associated with an increase in nuclear localization of DeltaNp73. Qct treatment in combination with TMZ abolished drug insensitivity and caused a more than additive induction of apoptosis compared to either treatment alone. Treatment with Qct, caused redistribution of DeltaNp73 into the cytoplasm and nucleus, which has been associated with increased p53 transcriptional activity. Knockdown of DeltaNp73 restored PARP cleavage in the TMZ treated cells, confirming its anti-apoptotic role. The response to treatment was predominantly p53 mediated as the p53 mutant SK Mel 28 cells showed no significant enhancement of apoptosis.CONCLUSION:This study demonstrates that Qct can sensitize cells to TMZ and that the mechanisms of sensitization involve modulation of p53 family members.
EISSN:
 1471-2407
DOI:
10.1186/1471-2407-10-282
Version:
Final published version
Additional Links:
http://www.biomedcentral.com/1471-2407/10/282

Full metadata record

DC FieldValue Language
dc.contributor.authorThangasamy, Thilakavathyen
dc.contributor.authorSittadjody, Sivanandaneen
dc.contributor.authorMitchell, Geoffreyen
dc.contributor.authorMendoza, Erinen
dc.contributor.authorRadhakrishnan, Vijayababuen
dc.contributor.authorLimesand, Kirstenen
dc.contributor.authorBurd, Randyen
dc.date.accessioned2016-05-20T09:04:42Z-
dc.date.available2016-05-20T09:04:42Z-
dc.date.issued2010en
dc.identifier.citationThangasamy et al. BMC Cancer 2010, 10:282 http://www.biomedcentral.com/1471-2407/10/282en
dc.identifier.doi10.1186/1471-2407-10-282en
dc.identifier.urihttp://hdl.handle.net/10150/610343-
dc.description.abstractBACKGROUND:The alkylating agent Dacarbazine (DTIC) has been used in the treatment of melanoma for decades, but when used as a monotherapy for cancer only moderate response rates are achieved. Recently, the clinical use of Temozolomide (TMZ) has become the more commonly used analog of DTIC-related oral agents because of its greater bioavailability and ability to cross the blood brain barrier. The response rates achieved by TMZ are also unsatisfactory, so there is great interest in identifying compounds that could be used in combination therapy. We have previously demonstrated that the bioflavonoid quercetin (Qct) promoted a p53-mediated response and sensitized melanoma to DTIC. Here we demonstrate that Qct also sensitizes cells to TMZ and propose a mechanism that involves the modulation of a truncated p53 family member, DeltaNp73.METHODS:DB-1 melanoma (p53 wildtype), and SK Mel 28 (p53 mutant) cell lines were treated with TMZ (400 muM) for 48 hrs followed by Qct (75 muM) for 24 hrs. Cell death was determined by Annexin V-FITC staining and immunocytochemical analysis was carried out to determine protein translocation.RESULTS:After treatment with TMZ, DB-1 cells demonstrated increased phosphorylation of Ataxia telangiectasia mutated (ATM) and p53. However, the cells were resistant to TMZ-induced apoptosis and the resistance was associated with an increase in nuclear localization of DeltaNp73. Qct treatment in combination with TMZ abolished drug insensitivity and caused a more than additive induction of apoptosis compared to either treatment alone. Treatment with Qct, caused redistribution of DeltaNp73 into the cytoplasm and nucleus, which has been associated with increased p53 transcriptional activity. Knockdown of DeltaNp73 restored PARP cleavage in the TMZ treated cells, confirming its anti-apoptotic role. The response to treatment was predominantly p53 mediated as the p53 mutant SK Mel 28 cells showed no significant enhancement of apoptosis.CONCLUSION:This study demonstrates that Qct can sensitize cells to TMZ and that the mechanisms of sensitization involve modulation of p53 family members.en
dc.language.isoenen
dc.publisherBioMed Centralen
dc.relation.urlhttp://www.biomedcentral.com/1471-2407/10/282en
dc.rights© 2010 Thangasamy et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0)en
dc.titleQuercetin abrogates chemoresistance in melanoma cells by modulating DeltaNp73en
dc.typeArticleen
dc.identifier.eissn 1471-2407en
dc.contributor.departmentDepartment of Nutritional Sciences, University of Arizona, Tucson, AZ 85721, USAen
dc.contributor.departmentCancer Biology Interdisciplinary Program, University of Arizona, Tucson, AZ 85721, USAen
dc.contributor.departmentArizona Cancer Center, University of Arizona, Tucson, AZ 85721, USAen
dc.identifier.journalBMC Canceren
dc.description.collectioninformationThis item is part of the UA Faculty Publications collection. For more information this item or other items in the UA Campus Repository, contact the University of Arizona Libraries at repository@u.library.arizona.edu.en
dc.eprint.versionFinal published versionen
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