[Polyadenylation signal-deficient retroviruses transformation of human gastric epithelial GES-1 cells].
OBJECTIVE
To verify if mutated polyadenylation signal retroviruses can produce viral-host readthrough transcripts (Rth) and have the ability to transform human gastric epithelial GES-1 cells, and to discuss the new functions of retroviruses in gastric cancer related gene research.


METHODS
The polyadenylation signal-deficient retrovirus vector mutated by PCR site-directed mutagenesis was used to make polyadenylation signal-deficient retroviruses by PA317 packaging cells. The GES-1 cells were infected by the viruses and selected by G418. Viral-host readthrough RNAs were checked by Northern blot. The cell growth and soft agar assay were run to test the transformed cells.


RESULTS
polyadenylation signal-deficient retroviruses could be packaged by PA317 packaging cells. The viruses had the ability to infect GES-1 cells. Northern blot analysis of viral RNA from infected pools and individual G418-resistant clones demonstrated that mutation of consensus LTR polyadenylation signals generated Rth viral RNA in the infected GES-1 cells. Phenotypic analysis results showed that the GES-1 cells infected with plyadenylation signal mutant viruses tended to grow in a cluster manner. Pools of PA317 cells infected with mutant viruses were able to form colonies in soft agar with a higher efficiency than control or uninfected cells.


CONCLUSIONS
Host readthrough transcripts generated by polyadenylation signal mutant viruses may contribute to transformation GES-1 cell phenotypes. The mutant vectors and the method described in the present work may be useful as tools to trap and identify genes involved in retroviral insertion mediated cell transformation.
Lan
Hai
H
Department of Immunology, The School of Oncology, Peking University, Beijing Institute for Cancer Research, Beijing, 100036, China.
Zhang
Qing-yun
QY
Xu
Jian-jun
JJ
Wang
Ya-ming
YM
D000818:Animals; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D004847:Epithelial Cells / Q000166:cytology* / Q000378:metabolism / Q000821:virology; D005347:Fibroblasts / Q000166:cytology / Q000821:virology; D006801:Humans; D051379:Mice; D016297:Mutagenesis, Site-Directed; D039104:RNA 3' Polyadenylation Signals / Q000235:genetics*; D012367:RNA, Viral / Q000378:metabolism; D012190:Retroviridae / Q000235:genetics*; D013270:Stomach / Q000166:cytology; D020079:Terminal Repeat Sequences
D012367:RNA, Viral