Proliferative activity, apoptosis and expression of oestrogen receptor and Bcl-2 oncoprotein in canine mammary gland tumours.
Samples of 39 canine mammary gland tumours (MGTs) were examined immunohistochemically for oestrogen receptor (ER-alpha), Bcl-2 protein and Ki67 antigen, and by TUNEL assay for apoptosis. ER-alpha was expressed by 80% (31/39) of the tumours, including all of the 15 benign tumours and 67% (16/42) of the malignant tumours. ER-alpha expression was greater in the benign than in the malignant tumours (P<0.01). Bcl-2 protein was detected in 62% (24/39) of the MGTs, of which 67% (10/15) were benign and 58% (14/24) malignant. No significant difference in Bcl-2 expression between benign and malignant tumours was detected. The Ki67 and TUNEL indices were greater in malignant than in benign tumours (P<0.01). Correlation analysis suggested that ER-alpha and Bcl-2 expression were related, but this observation lacked statistical significance. The levels of cell proliferation and apoptosis did not appear to be significantly correlated with the expression of Bcl-2. A positive relationship was apparent between cell proliferation and apoptosis, whilst a negative correlation between ER-alpha and cell proliferation was demonstrated. In conclusion, the suggestion of a positive correlation between ER-alpha and Bcl-2 in canine MGTs indicates that ER may be the regulator of Bcl-2 protein, as in human breast cancer. In contrast to cell proliferation and apoptosis, ER-alpha and Bcl-2 expression were greater in benign MGTs than in their malignant counterparts.
Yang
W-Y
WY
Department of Veterinary Medicine, College of Bio-resources and Agriculture, National Taiwan University, No. 1 Sec. 4, Roosevelt Road, Taipei 106, Taiwan, ROC.
Liu
C-H
CH
Chang
C-J
CJ
Lee
C-C
CC
Chang
K-J
KJ
Lin
C-T
CT
D000818:Animals; D017209:Apoptosis; D002277:Carcinoma / Q000378:metabolism / Q000662:veterinary*; D049109:Cell Proliferation; D004283:Dog Diseases / Q000378:metabolism*; D004285:Dogs; D047628:Estrogen Receptor alpha / Q000378:metabolism*; D005260:Female; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D019394:Ki-67 Antigen / Q000378:metabolism; D008321:Mammary Glands, Animal / Q000378:metabolism*; D015674:Mammary Neoplasms, Animal / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D014599:Uterus / Q000378:metabolism
D047628:Estrogen Receptor alpha; D019394:Ki-67 Antigen; D019253:Proto-Oncogene Proteins c-bcl-2