The hypoxic tumor microenvironment in vivo selects tumor cells with increased survival against genotoxic stresses

Tumor sensitivity to radiation therapy has been known to be dependent on O2 concentrations. However, radiosensitivity of naturally occurring hypoxic tumor cells remains to be well fully investigated in direct comparison to that of their adjacent non-hypoxic tumor cells within the same tumor. We developed a hypoxia-sensing xenograft model using the hypoxia-response element (HRE)-driven enhanced green fluorescence protein (EGFP) as a hypoxia reporter to identify hypoxic tumor cells in situ. Here, we have found that naturally hypoxic tumor cells are moderately radioresistant compared to their neighboring non-hypoxic tumor cells in the same tumor.
Source: Cancer Letters - Category: Cancer & Oncology Authors: Tags: Original Articles Source Type: research