There is increasing evidence that genes are involved in normal cell growth and diffrerentiation and genes that encode for growth factors are important in determining the development and biologic aggressiveness of the bladder tumor.
Sequential epithelial changes (normal, simple hyperplasia, nodular or papillary hyperplasia, papilloma and superficial transitional cell cacinoma-Ta, TIS) were observed in urinary bladder of rat in proportion to the duration of BBN
(N-butyl-4-hydroxybutyl nitrosamine) administration.
This study was undertaken to understand the roles of ras oncogenes & EGFR (epidermcl growth factor receptor ) in carcinogenesis of BBN induced bladder tumor.
Immunohistochemical staining for ras and ECFR was performed on nonaldehyde, Carnoy's solution -fixed tissues from BBN induced artificial bladder tumor of rat.
@ES The results are as follows :
@EN 1. The most frequently noted pathological change observed on hematoxyline and eosin stained sections was mold epithelial hyperplasia of the urinary bladder mucosa in early stage of BBN treated rats. With the time sequence, severe hyperplasia
and
papillary hyperplasia were seen. In late stage, papilloma and superficial transitional cell carcinoma were developed in some of them.
2. The expression of ras oncogene was weak in control in control group, but its immunoreavtivity was strong in experimental group and layers of positive cells were increased along with duration of carcinogen exposure.
3. In immunohistochemical staining for EGFR may play an important role in tumor development and progression in BBN exposure, immunoreactivity of the cells and positive cell layers of the mucosa were increased.
In summary, ras oncogogene and EGFR may play an important role in tumocr development and progression in BBN induced bladder tumor of rat. But further studies are required for its full significances of oncogene expression.
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