Induction of Apoptosis
in Tumor Cells by a Recombinant Adenovirus with bak Gene
Li Zhi-Da, Yi Wei, Qi Yi-Peng*, Li Yan
( Institute of virology, Wuhan University, Wuhan 430072，China )
Abstract Apoptosis,
a genetically encoded process of cellular suicide, comprises an intrinsic
cellular defence against tumorigenesis. bak(for bcl-2
homologous antagonist/killer) is a new apoptosis-inducing gene found recently,
which is identified in all tissues examined. Initial work of Farrow, Chittenden
and Klefer indicated that bak plays an important role in apoptosis.
Successive work of others suggests inactivity of Bak always accompanies the
development of tumor cells. In this work, a shuttle vector harboring bak
gene, pCA13-bak, was constructed and used to cotransfect into the cell
line 293 together with a recombinant plasmid, pBHG11, containing most of
adenovirus genome. A mutant adenovirus(delete E1, E3 region)carring bak,
Ad-bak, was obtained, and purified. Dot blot identified the
construction of recombinant virus was successful. HeLa cells were infected by
this virus. Some manners were used to identify the changes of HeLa cells
including Annexin V-FITC staining which made the reversed PS observed directly,
microscope observation and others. The characteristic morphology of apoptotic
cells was due to Ad-bak. The experiment suggests that bak is
a strong apoptosis-inducing gene, and a potential gene which could be used in
gene therapy on tumor.
Key words bak gene； adenovirus vector； apoptosis； gene therapy
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