Digital Repository

Investigating dynamics of checkpoint activation in response to DNA alkylation damage in breast epithelial cells

Show simple item record

dc.contributor.advisor LAHIRI, MAYURIKA en_US
dc.contributor.author SURAL, SUROJIT en_US
dc.date.accessioned 2012-05-04T11:13:05Z
dc.date.available 2012-05-04T11:13:05Z
dc.date.issued 2012-05 en_US
dc.identifier.uri http://dr.iiserpune.ac.in:8080/xmlui/handle/123456789/185
dc.description.abstract N-nitroso-N-methylurea (MNU) is an SN1 type DNA methylating agent which forms the modified base O6-methylguanine. Two major pathways involved in mediating DNA damage response in mammalian cells are ATM through Chk2 for double-strand breaks and ATR through Chk1 for single-strand breaks or stalled replication forks. We investigated the dynamics of checkpoint activation in breast adenocarcinoma-derived MCF7 cells at different concentrations of MNU and found a correlation between degradation of the suicidal repair enzyme O6-methylguanine DNA methyltransferase (MGMT) and activation of the DNA damage signaling pathways. ATM phosphorylation was detected at all MNU doses; however phosphorylation of effector kinases, Chk1 and Chk2, was observed only at lower MNU concentrations. Interestingly, at higher doses of MNU, activation of caspase 9 occurred in absence of Chk1 and Chk2 phosphorylation. MCF10A cells of normal breast epithelial origin and MGMT-depleted MCF7 cells showed activation of DNA damage checkpoint kinases at a much lower MNU concentration in comparison with MCF7 cells. ATM, Chk2 and Chk1 were phosphorylated at the same time point after induction of MNU damage; however for damage induced by the DNA ethylating agent N-nitroso-N-ethylurea (NEU), ATM and Chk2 phosphorylation preceded Chk1 phosphorylation. Interestingly, Chk1 phosphorylation induced after NEU damage was independent of ATM and DNA-PK activation. We have also established a 3-dimensional basement membrane culture of MCF10A cells to investigate early tumorigenic effects of MNU-induced damage during different stages of development of human mammary acini. en_US
dc.language.iso en en_US
dc.subject 2012
dc.subject DNA damage en_US
dc.subject DNA alkylation en_US
dc.title Investigating dynamics of checkpoint activation in response to DNA alkylation damage in breast epithelial cells en_US
dc.type Thesis en_US
dc.type.degree BS-MS en_US
dc.contributor.department Dept. of Biology en_US
dc.contributor.registration 20071006 en_US


Files in this item

This item appears in the following Collection(s)

  • MS THESES [1705]
    Thesis submitted to IISER Pune in partial fulfilment of the requirements for the BS-MS Dual Degree Programme/MSc. Programme/MS-Exit Programme

Show simple item record

Search Repository


Advanced Search

Browse

My Account