Related Experiment Video
Updated: Aug 17, 2026
Immunofluorescent Detection of Two Thymidine Analogues (CldU and IdU) in Primary Tissue
Published on: December 7, 2010
Thymidine analogues to assess microperfusion in human tumors
Hilde L Janssen1, Anna S Ljungkvist, Paul F Rijken
1Division of Experimental Therapy, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.
Purpose:
To validate the use of the thymidine analogues as local perfusion markers in human tumors (no labeling indicates no perfusion) by comparison with the well-characterized perfusion marker Hoechst 33342.
Methods And Materials:
Human tumor xenografts from gliomas and head-and-neck cancers were injected with iododeoxyuridine (IdUrd) or bromodeoxyuridine (BrdUrd) and the fluorescent dye Hoechst 33342. In frozen sections, each blood vessel was scored for the presence of IdUrd/BrdUrd labeling and Hoechst in surrounding cells. The percentage of analogue-negative vessels was compared with the fraction of Hoechst-negative vessels. Collocalization of the two markers was also scored.
Results:
We found considerable intertumor variation in the fraction of perfused vessels, measured by analogue labeling, both in the human tumor xenografts and in a series of tumor biopsies from head-and-neck cancer patients. There was a significant correlation between the Hoechst-negative and IdUrd/BrdUrd-negative vessels in the xenografts (r = 85, p = 0.0004), despite some mismatches on a per-vessel basis.
Conclusions:
Thymidine analogues can be successfully used to rank tumors according to their fraction of perfused vessels. Whether this fraction correlates with the extent of acute hypoxia needs further confirmation.
