Open Access[ 3 H]thymidine labels less than half of the DNA‐synthesizing cells in the mouse tumour, carcinoma NT
Author(s) -
Hamilton E.,
Dobbin J.
Publication year - 1982
Publication title -
cell proliferation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.647
H-Index - 74
eISSN - 1365-2184
pISSN - 0960-7722
DOI - 10.1111/j.1365-2184.1982.tb01058.x
Subject(s) - labelling , thymidine , dna , dna synthesis , microbiology and biotechnology , carcinoma , biology , deoxyuridine , chemistry , biochemistry , genetics
. We have studied carcinoma NT, a transplantable mouse adenocarcinoma of spontaneous origin. Cells labelled with [ 3 H]thymidine ([ 3 H]TdR) were restricted to a narrow zone around the periphery of this tumour and were also found in rings up to 50 μ m wide, around isolated blood vessels in the central necrotic area. Labelling with [ 3 H]deoxyuridine ([ 3 H]UdR), another DNA synthesis precursor, produced a very different pattern. The labelled zone around the periphery was much wider than with [ 3 H]TdR, and [ 3 H]UdR labelled cells were found up to 110 μ m from isolated vessels. [ 3 H]iododeoxyuridine ([ 3 H]IUdR) gave the same pattern of labelling as [ 3 H]UdR. In the heavily labelled zone, within 1 mm of the tumour periphery, the labelling index (LI) was 51% after [ 3 H]UdR or [ 3 H]IUdR injection, and only 36% with [ 3 H]TdR. The data show that at least half of the DNA‐synthesizing cells in this tumour did not incorporate [ 3 H]TdR. Previous workers reported cell loss factors for carcinoma NT of 60% calculated from [ 3 H]TdR labelling data and 30% from the rate of loss of [ 125 I]UdR. The present work suggests that calculations based on [ 125 I]UdR data are more likely to be accurate for carcinoma NT than those using [ 3 H]TdR data.