Exploring the time dependent changes on the sensitivity of breast cancer cells to various chemotherapies (tamoxifen) in a hypoxic environment

Cancer is a very heterogeneous disease, in which cells at various stages of neoplasia exist within one tumour mass. Within this tumour mass are cells with varying degrees of oxygen and nutrient supply; cells in the centre of the mass being more deficient. It has been shown that tumour stem cells are to be found among these hypoxic populations and that these cells are particularly resistant to treatment via both radiation and chemotherapy. Following treatment, these resistant stem cells form the basis of relapse or reoccurrence. Surviving cells undergo further transformation and, following relapse, are usually a more aggressive type.

Traditional methods for studying the effect on chemotherapy in vitro utilise incubators under normoxic conditions (normal oxygen levels). By utilising a hypoxic chamber, we can manipulate the oxygen supply and assess the different response of cells to various treatment options in both normoxic and hypoxic conditions.