Measuring DNA lesions induced by chemotherapeutic agents – DNA repair and DNA Damage
Autor(a) principal: | |
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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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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 |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10362/20321 |
url |
http://hdl.handle.net/10362/20321 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
repository.mail.fl_str_mv |
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1799137891630186496 |