Use this URL to cite or link to this record in EThOS:
Title: Investigating the role of ATM in sarcomas
Author: Alkathiri, Afnan
ISNI:       0000 0004 7651 6433
Awarding Body: University of Sheffield
Current Institution: University of Sheffield
Date of Award: 2018
Availability of Full Text:
Access from EThOS:
Full text unavailable from EThOS. Thesis embargoed until 13 Apr 2023
Access from Institution:
Sarcomas are a rare heterogeneous group of malignant tumours arising from cells of a mesenchymal origin. They are diverse group consisting of more than 50 subgroups. Sarcomas tend to fall into two district genetic categories. The first group shows relatively simple karyotypes with specific genetic abnormalities. The other group however has very complex karyotypes with unspecific genetic alterations. Although their causes are still not entirely clear, the strongest links appear to be radiation exposure and inherited cancer predisposition. Previous work in our laboratory has revealed a deletion in the ATM gene, particularly in gastrointestinal stromal tumours and in leiomyosarcomas. The ATM gene is known to have a key role in the repair of DNA-DSBs, as well as in cell cycle arrest. To investigate the role that ATM may have in sarcoma, Western blotting was initially used in this study to look for the total ATM protein expression and for the phosphorylated form of the ATM in different sarcoma subtypes. So as to examine the potential relevance of ATM to the tumours in more detail, the study also measured the kinetics of gH2ax foci formation and loss in established and primary sarcoma cells and in normal retinal cells; both endogenously and after inducing DNA-DSBs by 2Gy IR prior to, and after, the inhibition of ATM. The functional aspect of ATM in sarcoma was further explored through the clonogenic survival assay. Finally, the genetic abnormalities of the ATM were assessed using a combination of several techniques. Although this PhD study has confirmed ATM copy number deletion in sarcomas, this does not appear to affect protein expression, since expression was clearly detected by Western blotting at 370 kDa in all the cell lines tested in this study, including the control samples. This work has also demonstrated the existence of functional ATM in sarcoma samples while providing evidence that, even though ATM is inhibited in sarcomas, they are still able to undertake DNA repair, possibly via the utilisation of other pathways, or because an "abnormal" ATM in the sarcomas may not have been adequately inhibited due to a mutation. The importance of the ATM deletion/mutation to the protein expression seen in sarcoma cell lines, and the significance of ATM deletion/mutation to the biological behaviour of the sarcoma samples included in this work, needs further investigation in the near future.
Supervisor: Sisley, Karen Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available