Apoptotic index and apoptosis influencing proteins bcl-2, mcl-1, bax and caspases 3, 6 and 8 in pancreatic carcinoma.
OBJECTIVE
To study the expression of bcl-2, bax and mcl-1 and caspases 3, 6 and 8 and apoptosis in pancreatic carcinoma.


RESULTS
Eighty-seven pancreatic carcinomas were studied immunohistochemically with antibodies to bcl-2, mcl-1, bax and caspases 3, 6 and 8. Apoptosis was detected by the TUNEL method. bcl-2 and mcl-1 positivity was observed in 13% and 86% of the cases, while bax was observed in all of them. The bax immunoreactivity was weak in 30% of the tumours. Caspase 3, 6 and 8 immunoreactivity was observed in 80%, 80% and 74% of the cases, respectively. The staining was mainly cytoplasmic and diffuse, but sometimes also fragmented granular (mainly caspase 6) or membrane-associated (mainly caspase 8) staining was seen. The mean apoptotic index in pancreatic carcinomas was 0.69%. The apoptotic index in bcl-2 positive cases was lower (0.35%) than in cases showing no immunoreactivity (0.64%) (P = 0.013). The apoptotic index was higher in tumours with strong bax immunoreactivity (0.70%) than in the other cases (0.34%) (P = 0.002). There was no significant association between the apoptotic index and the expression of mcl-1 or caspases 3, 6 and 8.


CONCLUSIONS
Both bcl-2 and bax influence the extent of apoptosis in pancreatic carcinoma. The strong expression of caspases 3, 6 and 8 in pancreatic carcinoma is evidence of the activation of the apoptotic machinery in malignant cells in pancreatic carcinoma and shows that the genes of these proteins are often upregulated in them.
Virkajärvi
N
N
Department of Pathology, University of Oulu, Finland.
Pääkkö
P
P
Soini
Y
Y
D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology; D017209:Apoptosis; D053148:Caspase 3; D053178:Caspase 6; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases / Q000096:biosynthesis*; D004792:Enzyme Precursors / Q000096:biosynthesis; D006801:Humans; D007150:Immunohistochemistry; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D010190:Pancreatic Neoplasms / Q000378:metabolism / Q000473:pathology*; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis*; D051028:bcl-2-Associated X Protein
C494826:BAX protein, human; D004792:Enzyme Precursors; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D009363:Neoplasm Proteins; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; C505407:CASP3 protein, human; C505514:CASP6 protein, human; C505530:CASP8 protein, human; C506433:CASP9 protein, human; D053148:Caspase 3; D053178:Caspase 6; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases