Bcl-2 protein expression and gut neurohormonal polypeptidelamine production in colorectal carcinomas and tumor-neighboring mucosa, which closely correlate to the occurrence of tumor
To clarify whether advanced colorectal carcinomas
and tumor-neighboring mucosa simultaneously
produce both Bcl-2 protein and gut neurohormonal
polypeptides andlor amines, and the interrelationship of
these phenomenon, we studied retrospective analysis of
Bcl-2 protein production and neuroendocrine characteristics
in 52 cases of advanced colorectal carcinoma and
surrounding mucosa. All of the tumor-neighboring
mucosa presented hyperplasia. The rates of enhanced
immunoreactivity of the tumor-neighboring mucosa and
of positive immunoreactivity of the carcinomas against
human Bcl-2 protein and against human vasoactive
intestinal polypeptide, pancreatic polypeptide and
somatostatin were 78.8% and 94.2%, 82.7% and 59.6%,
78.8% and 67.3%, and 88.5% and 84.6% respectively.
Double immunostaining for Bcl-2 protein and each
peptide hormone revealed simultaneous expression. In
contrast, that of tumor-neighboring mucosa and
carcinomas to serotonin and chromogranin-A and to
argyrophilia were 11.5% and 1.9%, 32.7% and 17.3%,
and 26.9% and 21.2%, respectively. We concluded that
tumor-neighboring crypt cells displayed not only
hyperplasia but also neuroendocrine characteristics and
that enhanced Bcl-2 protein immunoreactivity correlated
with tumor occurrence in the wall of the colorectum. The
production of Bcl-2 protein by tumor cells and tumorneighboring
crypt cells indicates that the bcl-2 protooncogene
may act not only as an inhibitor of apoptosis
but also as an inducer of neuroendocrine differentiation
from the latent characteristics of the endodermal stem cell