Measuring DNA lesions induced by chemotherapeutic agents – DNA repair and DNA Damage

Detalhes bibliográficos
Autor(a) principal: Pinheiro, Cláudio Alexandre Almeida
Data de Publicação: 2016
Tipo de documento: Dissertação
Idioma: eng
Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
Texto Completo: http://hdl.handle.net/10362/20321
Resumo: DNA-damaging chemotherapy is amongst the main kinds of cancer treatment. Conversely, our cells are exposed to a wide variety of factors that may cause DNA lesions which, by themselves, may be precursors of cancer development. Cancer genomes, as a whole, accumulate mutations (‘driver’ and ‘passenger’ mutations) which may amount to more than 1000 in cancer-associated genes. These mutations may ensue from a multiplicity of exogenous and endogenous DNA damaging agents, as well as by less proficient DNA repair processes. The first line of cell defense against DNA damage is attributed to BER pathway. The main aim of this study was evaluate the role of BER pathway through the measure of DNA lesions induced by chemotherapeutic agents. Three genes acting on BER pathway were individually silenced in HeLa cells: PARP1, XRCC1 and APE1. These silenced cell-lines were then exposed individually to three different chemotherapeutic agents used in cancer therapy: doxorubicin (DOX); paclitaxel (PAX); and 5-fluorouracil (5-FU), and the DNA damage induced by these agents was measured by comet assay. Our results showed that, globally, silenced cell lines were slightly resistant to drugs exposure than wild-type ones. Furthermore, the effect of DNA lesion measured by % DNA in tail induced by 5-FU and PAX was similar to the one reported for negative control in all cell lines. However, the effect measured for H2O2 (Positive Control) exposure was the inverse, the silenced cell lines showed much more lesion that the wild-type, which might be representative of the lesion type. In conclusion, the impact of each gene silencing on the genotoxicity of individual agents was not fully clear. Additional approaches able to measure other end-points (e.g. apoptosis) are fundamental to better understand the role of BER genes in DNA induced lesion.
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spelling Measuring DNA lesions induced by chemotherapeutic agents – DNA repair and DNA DamageBER pathwayComet assayDNA damageHeLa cellsDNA repairChemotherapeutic agentsDomínio/Área Científica::Engenharia e Tecnologia::Outras Engenharias e TecnologiasDNA-damaging chemotherapy is amongst the main kinds of cancer treatment. Conversely, our cells are exposed to a wide variety of factors that may cause DNA lesions which, by themselves, may be precursors of cancer development. Cancer genomes, as a whole, accumulate mutations (‘driver’ and ‘passenger’ mutations) which may amount to more than 1000 in cancer-associated genes. These mutations may ensue from a multiplicity of exogenous and endogenous DNA damaging agents, as well as by less proficient DNA repair processes. The first line of cell defense against DNA damage is attributed to BER pathway. The main aim of this study was evaluate the role of BER pathway through the measure of DNA lesions induced by chemotherapeutic agents. Three genes acting on BER pathway were individually silenced in HeLa cells: PARP1, XRCC1 and APE1. These silenced cell-lines were then exposed individually to three different chemotherapeutic agents used in cancer therapy: doxorubicin (DOX); paclitaxel (PAX); and 5-fluorouracil (5-FU), and the DNA damage induced by these agents was measured by comet assay. Our results showed that, globally, silenced cell lines were slightly resistant to drugs exposure than wild-type ones. Furthermore, the effect of DNA lesion measured by % DNA in tail induced by 5-FU and PAX was similar to the one reported for negative control in all cell lines. However, the effect measured for H2O2 (Positive Control) exposure was the inverse, the silenced cell lines showed much more lesion that the wild-type, which might be representative of the lesion type. In conclusion, the impact of each gene silencing on the genotoxicity of individual agents was not fully clear. Additional approaches able to measure other end-points (e.g. apoptosis) are fundamental to better understand the role of BER genes in DNA induced lesion.Silva, SusanaBorba, HelenaRUNPinheiro, Cláudio Alexandre Almeida2017-03-16T16:24:00Z2016-112017-032016-11-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfhttp://hdl.handle.net/10362/20321enginfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2024-03-11T04:04:10Zoai:run.unl.pt:10362/20321Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-20T03:26:08.031640Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse
dc.title.none.fl_str_mv Measuring DNA lesions induced by chemotherapeutic agents – DNA repair and DNA Damage
title Measuring DNA lesions induced by chemotherapeutic agents – DNA repair and DNA Damage
spellingShingle Measuring DNA lesions induced by chemotherapeutic agents – DNA repair and DNA Damage
Pinheiro, Cláudio Alexandre Almeida
BER pathway
Comet assay
DNA damage
HeLa cells
DNA repair
Chemotherapeutic agents
Domínio/Área Científica::Engenharia e Tecnologia::Outras Engenharias e Tecnologias
title_short Measuring DNA lesions induced by chemotherapeutic agents – DNA repair and DNA Damage
title_full Measuring DNA lesions induced by chemotherapeutic agents – DNA repair and DNA Damage
title_fullStr Measuring DNA lesions induced by chemotherapeutic agents – DNA repair and DNA Damage
title_full_unstemmed Measuring DNA lesions induced by chemotherapeutic agents – DNA repair and DNA Damage
title_sort Measuring DNA lesions induced by chemotherapeutic agents – DNA repair and DNA Damage
author Pinheiro, Cláudio Alexandre Almeida
author_facet Pinheiro, Cláudio Alexandre Almeida
author_role author
dc.contributor.none.fl_str_mv Silva, Susana
Borba, Helena
RUN
dc.contributor.author.fl_str_mv Pinheiro, Cláudio Alexandre Almeida
dc.subject.por.fl_str_mv BER pathway
Comet assay
DNA damage
HeLa cells
DNA repair
Chemotherapeutic agents
Domínio/Área Científica::Engenharia e Tecnologia::Outras Engenharias e Tecnologias
topic BER pathway
Comet assay
DNA damage
HeLa cells
DNA repair
Chemotherapeutic agents
Domínio/Área Científica::Engenharia e Tecnologia::Outras Engenharias e Tecnologias
description DNA-damaging chemotherapy is amongst the main kinds of cancer treatment. Conversely, our cells are exposed to a wide variety of factors that may cause DNA lesions which, by themselves, may be precursors of cancer development. Cancer genomes, as a whole, accumulate mutations (‘driver’ and ‘passenger’ mutations) which may amount to more than 1000 in cancer-associated genes. These mutations may ensue from a multiplicity of exogenous and endogenous DNA damaging agents, as well as by less proficient DNA repair processes. The first line of cell defense against DNA damage is attributed to BER pathway. The main aim of this study was evaluate the role of BER pathway through the measure of DNA lesions induced by chemotherapeutic agents. Three genes acting on BER pathway were individually silenced in HeLa cells: PARP1, XRCC1 and APE1. These silenced cell-lines were then exposed individually to three different chemotherapeutic agents used in cancer therapy: doxorubicin (DOX); paclitaxel (PAX); and 5-fluorouracil (5-FU), and the DNA damage induced by these agents was measured by comet assay. Our results showed that, globally, silenced cell lines were slightly resistant to drugs exposure than wild-type ones. Furthermore, the effect of DNA lesion measured by % DNA in tail induced by 5-FU and PAX was similar to the one reported for negative control in all cell lines. However, the effect measured for H2O2 (Positive Control) exposure was the inverse, the silenced cell lines showed much more lesion that the wild-type, which might be representative of the lesion type. In conclusion, the impact of each gene silencing on the genotoxicity of individual agents was not fully clear. Additional approaches able to measure other end-points (e.g. apoptosis) are fundamental to better understand the role of BER genes in DNA induced lesion.
publishDate 2016
dc.date.none.fl_str_mv 2016-11
2016-11-01T00:00:00Z
2017-03-16T16:24:00Z
2017-03
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/masterThesis
format masterThesis
status_str publishedVersion
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dc.language.iso.fl_str_mv eng
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dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
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