Relationship of p53, Bcl-2, Ki-67 index and E-cadherin expression in early invasive breast cancers with comedonecrosis as an accelerated apoptosis.
OBJECTIVE
To study the relationship between comedonecrosis formation and morphology, apoptosis, and p53, Bcl-2, Ki-67 index and E-cadherin expression in early invasive breast cancer.


METHODS
Early invasive breast cancers were first divided into two groups according to the presence (CN+ tumours) or absence (CN- tumours) of comedonecrosis. The histological grade, apoptosis, and expression of E-cadherin, Ki-67, p53 and Bcl-2 in the cancer-affected area, and in normal ducts from the specimen, were then examined.


RESULTS
Less tubule and gland formation was seen in CN+ tumours than in CN- tumours, although the histological grade between the groups was not different. During early comedonecrosis, cells undergo apoptosis and subsequent necrosis. p53 was higher in CN+ tumours than in CN- tumours and normal ducts, whereas Bcl-2 was lower in CN+ tumours than in CN- tumours and normal ducts. Both tumours had higher Ki-67 than in normal ducts, but no difference was evident between the tumours. CN+ tumours had slightly higher E-cadherin than that in CN- tumours, but lower than that in normal ducts. The level of comedonecrosis was positively correlated with p53, but inversely correlated with Bcl-2 in all tumours, and p53 and Bcl-2 were inversely correlated with each other. Furthermore, comedonecrosis and p53 were correlated with Ki-67 in CN+ tumours, and Bcl-2 was correlated with Ki-67 in CN- tumours.


CONCLUSIONS
Comedonecrosis may be actively regulated through an apoptotic procedure in massive cancers for their survival and progression, and the above proteins may be associated cooperatively in this process. CN+ and CN- tumours may have opposite proliferative systems under the p53-Bcl-2 pathway.
Hosaka
N
N
Department of Clinical Pathology, Toyooka Hospital, Hyogo, Japan.
Ryu
T
T
Cui
W
W
Li
Q
Q
Nishida
A
A
Miyake
T
T
Takaki
T
T
Inaba
M
M
Ikehara
S
S
D017209:Apoptosis; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology; D015820:Cadherins / Q000378:metabolism; D018270:Carcinoma, Ductal, Breast / Q000378:metabolism / Q000473:pathology; D005260:Female; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism; D009336:Necrosis; D009361:Neoplasm Invasiveness; D009363:Neoplasm Proteins / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
D015820:Cadherins; D019394:Ki-67 Antigen; D009363:Neoplasm Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53