The Radiosensitivity of Human Neuroblastoma Cells Grown As Multicellular Tumour Spheroids

Berry, Isabella Jackson (1988) The Radiosensitivity of Human Neuroblastoma Cells Grown As Multicellular Tumour Spheroids. MSc(R) thesis, University of Glasgow.

Abstract

Multicellular Tumour Spheroids (MTS) are a useful in vitro models of human cancer. Two cell lines - NB1-G and 1MR-32 - derived from two human neuroblastomas, were grown as MTS and were subjected to single, split and fractionated irradiation. The NB1-G MTS line is radiosensitive, with low capacity for repair of sublethal damage, which indicated that NB1-G may be a suitable cell line to test the theoretical advantage of hyperfractionation. The single dose response of 1MR-32 MTS, suggested that, intypically for neuroblastoma, 1MR-32 cells possessed a significant 'shoulder' on the cell survival curve. Fractionated radiation regimes were designed to be theoretically isoeffective for damage to late responding normal tissues (calculated using the linear-quadratic mathematical model with alpha/beta = 3GY). The radiation responses of MTS were evaluated using the end-points of regrowth delay and 'proportion cured' Regimens using smaller doses per fraction were found to be markedly more effective in causing damage to the NB1-G MTS, as assessed by either end-point. The isoeffective regimens caused approximately equal damage to 1MR-32 spheroids also. The findings were consistent with a substantial repair capacity for 1MR-32 MTS and implied that the well-known clinical heterogeneity of neuroblastoma might extend to its cellular radiobiology. These experimental findings support the proposal that hyperfractionation should be a therapeutically advantageous strategy in the treatment of tumours whose radiobiological properties are similar to those of the MTS neuroblastoma line NB1-G but not in the case of 1MR-32 MTS. On the basis of these results, it seems plausible that hyperfractionation would not be a universally advantageous strategy, but one whose efficacy is likely to depend on being able to select aporopriate tumours for this form of treatment.

• Item Type: Thesis (MSc(R))
• Qualification Level: Masters
• Keywords: Cellular biology, Oncology
• Date of Award: 1988
• Depositing User: Enlighten Team
• Unique ID: glathesis:1988-77763
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 14 Jan 2020 11:53
• Last Modified: 14 Jan 2020 11:53
• URI: https://theses.gla.ac.uk/id/eprint/77763