Immunocytochemical assessment of mitotic activity with an antibody to phosphorylated histone H3 in the macaque and human endometrium.
BACKGROUND
Determination of the mitotic index in sections of endometrium stained with haematoxylin and eosin (H&E) is difficult and time-consuming. We assessed the value of two mitotic markers as immunocytochemical reagents for measuring mitotic rates in endometrium.


METHODS
Mitotic protein monoclonal antibody 2 (MPM-2) and anti-phosphorylated histone H3 (Phospho H3) were applied to paraffin sections of rhesus macaque and human endometrium.


RESULTS
In estrogen-treated macaque endometrium the mean +/- SEM mitotic indices were: H&E 1.5 +/- 0.25%, Phospho H3 antibody 1.02 +/- 0.23% and MPM-2 antibody 0.69 +/- 0.17%; these were not statistically significantly different, but the Phospho H3 antibody gave a stronger and cleaner signal than the MPM-2 antibody. Comparisons were made between a computer-determined Phospho H3 index, the H&E-determined mitotic index and the Ki-67 index in samples of human endometrium across the cycle. All revealed that the highest proliferative rate occurred during the follicular phase, but the Phospho H3 and the mitotic indices were more highly correlated (R(2) = 0.89, P < 0.001) than the Ki-67 and mitotic indices (R(2) = 0.74, P < 0.05).


CONCLUSIONS
The exceptionally high contrast staining and the excellent correlation between the Phospho H3 and mitotic indices validates the specificity of the Phospho H3 antibody as a new tool for the assessment of endometrial mitotic activity.
Brenner
Robert M
RM
Oregon National Primate Research Center, 505 NW 185th Ave., Beaverton 97006, USA. brennerr@ohsu.edu
Slayden
Ov D
OD
Rodgers
William H
WH
Critchley
Hilary O D
HO
Carroll
Rebecca
R
Nie
Xiao Jing
XJ
Mah
Kuni
K
D000328:Adult; D000818:Animals; D000911:Antibodies, Monoclonal; D003201:Computers; D004717:Endometrium / Q000737:chemistry* / Q000166:cytology*; D005260:Female; D000072278:Forkhead Box Protein M1; D051858:Forkhead Transcription Factors; D006657:Histones / Q000032:analysis*; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D008253:Macaca mulatta; D008597:Menstrual Cycle; D051379:Mice; D008875:Middle Aged; D008938:Mitosis; D010750:Phosphoproteins / Q000032:analysis*; D010766:Phosphorylation; D012984:Software; D014157:Transcription Factors
D000911:Antibodies, Monoclonal; C107585:FOXM1 protein, human; D000072278:Forkhead Box Protein M1; D051858:Forkhead Transcription Factors; C491524:Foxm1 protein, mouse; D006657:Histones; D010750:Phosphoproteins; D014157:Transcription Factors