Local hypoxia is produced at sites of intratumour injection.
Bottom Line: Hoechst-labelled cells sorted from these tumours were more sensitive to killing by hypoxic cell cytotoxins (tirapazamine, RSU-1069) and less sensitive to damage by ionizing radiation.Hoechst-labelled cells also bound the hypoxia marker pimonidazole when given by i.p. injection.This effect could have significant implications for intratumour injection of drugs, cytokines or vectors that are affected by the oxygenation status of the tumour cells as well as potential effects on biodistribution via local microvasculature.
Affiliation: Medical Biophysics Department, British Columbia Cancer Research Centre, 601 W 10th Avenue, Vancouver, BC, V5Z 1L3 Canada. email@example.comShow MeSH
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Mentions: Since the drug concentration was highest in cells along the track of the needle, one could argue that more damage occurred here simply because these cells were exposed to the highest drug dose. Therefore, response to ionizing radiation, which produces three times more killing in aerobic than hypoxic cells, was also used to determine whether cells bordering the needle track were hypoxic. Tumours that had been injected with Hoechst 5 min before exposure to radiation showed less killing of the brightly fluorescent cells compared to the dimmest cells (Figure 3Figure 3
Affiliation: Medical Biophysics Department, British Columbia Cancer Research Centre, 601 W 10th Avenue, Vancouver, BC, V5Z 1L3 Canada. firstname.lastname@example.org