The role of bcl-2 in the progression of the colorectal adenoma-carcinoma sequence.
BACKGROUND
The bcl-2 proto-oncogene is a known inhibitor of apoptosis that may allow the accumulation and propagation of cells containing genetic alterations.


METHODS
An immunohistochemical study was performed to examine the role of BCL-2 protein expression in normal colonic mucosa, adenoma, and adenocarcinoma.


RESULTS
BCL-2 was present in the crypt base of normal mucosal glands, while diffuse expression of protein product was observed in 69 cases (65.1%) of adenoma and 29 cases (60%) of adenocarcinoma (p > 0.5). A diffuse expression pattern was often noted in adenomas of the tubular type, solitary lesions, small lesions (< 1 cm), and those with mild glandular dysplasia (p < 0.05, respectively). There was, however, no apparent difference as to location, Yamada type of gross appearance, and gender of patients (p > 0.05, respectively). Patterns of BCL-2 expression did not correlate with the biologic indicators of adenocarcinoma (p > 0.1, respectively).


CONCLUSIONS
Our results support that bcl-2 may play an important role in the early stage of the adenoma-carcinoma sequence. Down-regulation of bcl-2 is associated with the risk of malignant transformation for colorectal adenoma.
Yang
H B
HB
Department of Pathology, National Cheng Kung University Hospital, Tainan, Taiwan, Republic of China.
Chow
N H
NH
Sheu
B S
BS
Chan
S H
SH
Chien
C H
CH
Su
I J
IJ
D000230:Adenocarcinoma / Q000175:diagnosis / Q000378:metabolism*; D000236:Adenoma / Q000175:diagnosis / Q000378:metabolism*; D000328:Adult; D003106:Colon / Q000378:metabolism; D015179:Colorectal Neoplasms / Q000175:diagnosis / Q000378:metabolism*; D018450:Disease Progression; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D000090063:Proto-Oncogene Mas; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis*
C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D019253:Proto-Oncogene Proteins c-bcl-2