A Step Toward Personalized Cancer Treatment Simultaneous Detection of Multiple Types of Chemotherapyinduced DNA Damage Using Single Molecule Imaging
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Program
Biotechnology (MPBIO), MSc
Publicerad
2022
Författare
Foss, Ebba
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Chemotherapy is commonly used to treat cancer today, either alone or more commonly
as part of combination therapy. Response to a certain chemotherapeutic
agent is highly individual, both in terms of treatment efficacy and the extent to
which healthy cells are affected. For several drugs, induced DNA damage provides
the main cytotoxic effect, and a method for evaluating this damage could therefore
prove a powerful tool in treatment planning. In this thesis, a single molecule imaging
approach is used to assess chemotherapy-induced DNA damage, allowing visualisation
of damage sites on individual DNA strands. While previous studies have focused
on one damage type, or collective damage without distinction between types, a novel
modification to pre-existing techniques that allows for this distinction has recently
been demonstrated. In this thesis, the alkylating agent temozolomide was used to
illustrate how different damage types can be distinguished with a single molecule
imaging approach. This is done using repair enzymes associated with different DNA
repair pathways. The repair enzymes sequentially incorporate spectrally distinct
fluorescent nucleotides at the damage site which are then visualized as fluorescent
spots of two different colours on individual DNA molecules. This distinction could
be shown with high repeatability in terms of colour ratio. While both enzymes used
separately clearly repaired the treated DNA, there appeared to be an overlap when
applying them sequentially. This could suggest a problem with enzyme specificity.
Further exploration of this issue is needed to verify the feasibility of single molecule
imaging for the purpose of simultaneous detection of chemotherapy-induced DNA
damage types.
Beskrivning
Ämne/nyckelord
DNA damage , Single Molecule Imaging , Chemotherapy , Temozolomide , Simultaneous Labelling , DNA alkylation