[Effects of wild type PTEN gene on proliferation, apoptosis and the influence on apoptosis key factor Bcl-2 and Caspase family on K562 cells].
OBJECTIVE
To investigate the effect of tumor-suppressing gene,wild type PTEN gene, mediated by adenovirus vector on the cell proliferation, apoptosis and the influence on apoptosis key factor Bcl-2 and Caspase family on human chronic myeloid leukemia (CML) cell line K562 in vitro.


METHODS
The recombinated Ad-PTEN gene containing green fluorescent protein gene (Ad-PTEN-GFP) or the empty vector (Ad-GFP) was transfected into K562 cells. The growth of K562 cells was evaluated by MTT assay; the transfection efficiency of Ad-PTEN-GFP, apoptosis rate and proliferation index (PI) were assessed by flow cytometry (FCM). Morphological characteristics of transfected cells under light and transmission electron microscope were applied to demonstrated the apoptosis; DNA ladder and fluorescent staining were also tested; the PTEN, Bcl-2 mRNA levels were detected by real-time fluorescent relative-quantification reverse transcriptional PCR (FQ-PCR); PTEN and Bcl-2 protein levels were detected by Western Blotting; and Caspase-3/7 and -9 protein activity were detected by corresponding kits.


RESULTS
The 200 multiplicity of infection (MOI) of Ad-PTEN-GFP was applied to transfect K562 cells. The maximum growth inhibiting ratio was 37.1%. The early and advanced apoptosis rates were higher than Ad-GFP group and untransfected group (P<0.05). After 3 days transfaction of PTEN gene the Bcl-2 mRNA and protein were 0.27 fold and 0.58 fold respectively; and the Caspase-3/7 and -9 protein activity increased in time-depentend manner after transfected with PTEN gene at the first 3 days compared with Ad-GFP group and untransfected group.


CONCLUSIONS
Over expression of PTEN gene can inhibit K562 cells proliferation and promote cell apoptosis probability via inhibiting Bcl-2 expression and up-regulating the Caspase-3/7 and -9 ability.
Cheng
Zhi-Yong
ZY
Department of Hematology, The Second Hospital of Hebei Medical University, Shijiazhuang 050000, China.
Liang
Wen-Tong
WT
Niu
Zhi-Yun
ZY
Xue
Fang
F
Yao
Li
L
Pan
Ling
L
D000256:Adenoviridae / Q000235:genetics / Q000378:metabolism; D017209:Apoptosis; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism; D053179:Caspase 7 / Q000235:genetics / Q000378:metabolism; D053453:Caspase 9 / Q000235:genetics / Q000378:metabolism; D020169:Caspases / Q000235:genetics / Q000378:metabolism*; D049109:Cell Proliferation; D006801:Humans; D020014:K562 Cells; D051059:PTEN Phosphohydrolase / Q000235:genetics*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics
D019253:Proto-Oncogene Proteins c-bcl-2; D011994:Recombinant Proteins; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human; D053148:Caspase 3; D053179:Caspase 7; D053453:Caspase 9; D020169:Caspases