藉基因微陣列篩選之基因p40/EBP2/NoBP與血管新生及腫瘤發生之功能研究

The p40/ EBP2/ NoBP was firstly discovered from the nucleolus of cancer cell. Transfect this
gene into animal cell could promote cell proliferation. In budding yeast, the gene function is
essential for rRNA and ribosome synthesis. In EBV infected cell, it could interact with viral
nuclear protein EBNA1 to maintain viral genome during cell division.
In our previous study of gene expression profile of gastric cancers with different vessel indexes,
we discovered that p40/ EBP2/ NoBP expressed in gastric cancer tissue. In order to identify the
relationship of p40/ EBP2/ NoBP with gastric cancer process and angiogenesis, In Northern
blotting assay, we had found that p40/ EBP2/ NoBP overexpressed in some gastric cancer tissues.
And its expression is downregulated in capillary-like HUVEC cultured on Matrixgel.
In monocyte –macrophage differentiation process, p40/ EBP2/ NoBP is also downregulted in
differentiated macrophage. In gene expression study of HUVEC treated with 15-d-PGJ2, a
antiangiogenesis drug, we had found that p40/ EBP2/ NoBP was also inhibited。
According to the previous publication and our findings, there are four major objects in this
project.
The first object is to identify the downregulation mechanism of p40/ EBP2/ NoBP in
HUVEC treated with 15-d-PGJ2. There are 8 Sp1 binding sites and 4 c-Ets-1 binding sites in
promoter region of p40/ EBP2/ NoBP (-500 to +1). We hypothesize that 15-d-PGJ2maybe inhibit
the binding activity of Sp1and c-Ets-1, moreover, doweregulate p40/ EBP2/ NoBP expression.
Finally, the endothelial cell proliferation is stopped.
The secondary object is to study the mechanism of p40/ EBP2/ NoBP in cell growth control.
There are many p40/ EBP2/ NoBP. homologues found in different species. And, this gene
overexpression can promote animal cell proliferation, but, the mechanism still unknown.
We suggest that the cell growth mechanism controlled by p40/ EBP2/ NoBP. maybe be similar in
different species. We will utilize immunoprecipitation assay of p40/ EBP2/ NoBP to identify its
interaction protein for its function study.
The third object is to evaluate the relationship between p40/ EBP2/ NoBP expression and EBV
infected gastric cancer. EBV infection is related to nasopharyngeal cacinoma, Burkitt’s
lymphoma.
There are publication reported that gastric lymphoepithelioma- like carcinoma almost had been
infected by EBV. In EBV infected cells, viral protein EBNA1 can interaction with p40/ EBP2/
NoBP to help viral genome separation during cell division. So, we hypothesize that p40/ EBP2/
NoBP should play an important role in EBV infected gastric cancer.
The forth object is to identify whether p40/ EBP2/ NoBP is a novel proto-oncogene. Our
previous data shown that p40/ EBP2/ NoBP transfected 3T3 cell although can’t form obvious
colony in soft agar assay, but they can divided 2 to 4 times, then stop growth. We plan to
cotransfect 3T3 with p40/ EBP2/ NoBP and ras, to monitor whether they can form colony. We
predict these results can identify the roles of p40/ EBP2/ NoBP in gastric cancer process and
angiogenesis.