bcl-2 protein expression is associated with better prognosis in colorectal cancer.
OBJECTIVE
To investigate the expression of bcl-2 in colorectal carcinoma and to examine its association with mediators of apoptosis (p53 and mdm-2), clinicopathological features and long-term outcome.


RESULTS
We determined by immunohistochemistry the expression of bcl-2 in 102 colorectal carcinomas with 10-year follow-up. In 66 of these cases in which we had previously assessed p53 status, no correlation was seen between bcl-2 and p53. The mdm-2 protein was not detected in any of the 66 cases. Cytoplasmic staining of the bcl-2 gene product was seen in the tumour cells of 22 cases (22%). Using a polymerase chain reaction technique we showed that overexpression of bcl-2 was not due to rearrangement of the bcl-2 gene. Expression of bcl-2 protein was related to tumour grade but was unrelated to patient age, sex, tumour site, tumour size or Dukes' stage. There was a trend towards increased survival in those whose tumours expressed bcl-2 protein (P = 0.055). When entered into a multivariate analysis, this survival difference was independent of tumour stage (P = 0.05).


CONCLUSIONS
These results suggest that bcl-2 expression in colorectal carcinoma is associated with a better long-term prognosis.
Leahy
D T
DT
Department of Pathology, University College Dublin and St. Vincent's Hospital, Ireland.
Mulcahy
H E
HE
O'Donoghue
D P
DP
Parfrey
N A
NA
D000368:Aged; D017209:Apoptosis; D001483:Base Sequence; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D017931:DNA Primers / Q000235:genetics; D005260:Female; D015870:Gene Expression; D015321:Gene Rearrangement; D019254:Genes, bcl-2; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009687:Nuclear Proteins; D011379:Prognosis; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics* / Q000378:metabolism*; D051736:Proto-Oncogene Proteins c-mdm2; D015996:Survival Rate; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
D017931:DNA Primers; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53; C497206:MDM2 protein, human; D051736:Proto-Oncogene Proteins c-mdm2