Mapping re-growth following chemotherapy in high-risk neuroblastoma : The research process in laboratory work

Abstract: The aim of the current study is to study characteristics of high-risk cancer cells within the childhood disease neuroblastoma (NB) by mapping regrowth after treatment with the chemotherapy doxorubicin (doxo). The cell-line SK-N-BE(2)-C (BE(2)-C) was used as a model. Results from a previous study by Hultman et al., (2018) have indicated that while a majority of BE(2)-C cells could be shown resilient to a 1 μM dose of doxorubicin (doxo), only a very small fractions had the capacity for immediate replication following a single or double treatment of doxo (“remaining replicating cells”; RRC). The current study aims to investigate if RRC are responsible for regrowth. Cultured BE(2)-C cells were exposed to doxo and labelled with the nucleoside analogues EdU (5-ethynyl-2’-deoxyuridine) and BrdU (5-bromo-2-deoxyuridine). The results from the current study indicated that the RRC subpopulation might not be responsible for regrowth since the nucleoside labelling was not shown to be present in the cells of the regrowing colonies. However, technical challenges, e.g. the settings of thresholds for EdU and BrdU detection, in combination with the dilution of DNA markers in replication, call for further studies using additional methods, e.g. isotope markers, in order to firmly conclude that other subpopulation(s) than the RRC population are responsible for regrowth. Apart from studying cell populations responsible for regrowth, a pilot study was performed including another combination of treatment using an ATM-inhibitor (KU-60019) together with the chemotherapy doxo. There were some measurement points missing, but the current results indicate that regrowth is postponed when the ATM-inhibitor is added in combination with single or double treatment of doxo. The research procedures and processes involved in this thesis, are similar to those included in the syllabi for the natural science subjects for the upper secondary school. This underlines the importance of studying inquiry and laboratory work. A literature review was performed, analysing current research on open-and closed ended laboratory work. Ten research articles were collected and characterized by natural science subject, type of laboratory style (open or closed) and student learning competences. Findings from the current study indicate that open-ended laboratory work promotes student interest in the subject. The learning competences problem-solving ability and procedure ability are most commonly studied in laboratory work based on the results from the current study.