Analysis of colon cancer cells that survive checkpoint adaptation after treatment with a genotoxic age
Date
2013
Authors
Rahman, Tanzila
University of Lethbridge. Faculty of Arts and Science
Journal Title
Journal ISSN
Volume Title
Publisher
Lethbridge, Alta. : University of Lethbridge, Dept. of Biological Sciences, c2013
Abstract
Most cancer treatments are genotoxic agents that target and damage DNA as part
of their mechanism of action. Recently, it was discovered that cancer cells with damaged
DNA can escape the DNA damage checkpoint and enter into mitosis, a process known as
checkpoint adaptation. I used the human colon carcinoma cell line (HT-29) as a model to
examine checkpoint adaptation in cells treated with camptothecin (CPT), a topoisomerase
I inhibitor that damages DNA. Survival and clonogenic assays revealed that
approximately between 1-3% of the cells that undergo checkpoint adaptation are able to
survive CPT treatment. Immunofluorescence microscopy disclosed that approximately
90% of the surviving cells were negative for histone -H2AX, whereas, in parallel, the
alkaline comet assay revealed that 73% of the cells displayed comets. Karyotype analysis
showed survival cells had 35 chromosomes on average, whereas non-treated cells
contained 65. FISH analysis revealed that survival cells appear to have major changes in
chromosome structure because 45% of the chromosomes were missing telomeres and
28% of the telomeres were located in positions other than the tips of chromosomes.
These findings provide valuable information about the integrity of the genome of cancer
cells that survive checkpoint adaptation.
Description
x, 93 leaves : ill. ; 29 cm
Keywords
Colon (Anatomy) -- Cancer , Colon (Anatomy) -- Cancer -- Cytopathology , Colon (Anatomy) -- Cancer -- Chemotherapy , Colon (Anatomy) -- Cancer -- Molecular aspects , Dissertations, Academic