[Inhibitory effect of lentiviral vector-mediated SHIP gene transfection on proliferation of leukemia K562 cells and PI3K/Akt pathway regulation].
OBJECTIVE
The hemopoietic-restricted Src homology 2-containing inositol 5'-phosphatase (SHIP) acts as a negative regulator for the proliferation and survival of hematopoietic cells by hydrolysing the phosphoinositide 3-kinase (PI3K)-generated second messenger, PtdIns(3,4,5)-P3 (PI-3,4,5-P3) to PtdIns(3,4)-P2 (PI-3,4-P2). This study was to investigate the biological function of SHIP gene in pathogenesis of leukemia cells by lentiviral vector-mediated SHIP transfection.


METHODS
Ectopic SHIP gene was transfected into leukemia K562 cells by the mediation of lentiviral vector. The mRNA level of SHIP was detected by fluorescent quantitative reverse transcription-polymerase chain reaction (FQ-PCR). The expression of SHIP, Akt, and phosphorylated Akt (p-Akt) was detected by Western blot. The proliferation and morphology of K562 cells before and after SHIP gene transfection were compared.


RESULTS
The proliferation of K562 cells was inhibited after transfection: the proliferation inhibition rate was increased from (9.9+/-1.5)% on Day 3 to (40.6+/-2.3)% on Day 5. K562 cells were SHIP-negative but expressed high level of p-Akt which was down-regulated from 0.533 to 0.245 (P<0.01) after SHIP transfection. Apoptotic characteristics were showed in K562 cells after SHIP transfection. The early apoptosis rate was significantly higher in K562-wtSHIP-FIV-G cells than in K562-FIV-G cells and untransfected K562 cells [(38.3+/-4.3)% vs. (8.2+/-0.9)% and (7.7+/-0.8)%, P<0.05].


CONCLUSIONS
SHIP gene can inhibit cell proliferation and promote cell apoptosis via inactivating PI3K/Akt pathway. Loss of SHIP might activate PI3K/Akt pathway and promote the proliferation of K562 cells.
Yang
Lin
L
Department of Hematology, The Second Affiliated Hospital, Hebei Midical University, Shijiazhuang, Hebei, 050000, PR China.
Luo
Jian-Min
JM
Liu
Xiao-Jun
XJ
Wen
Shu-Peng
SP
Du
Xing-Yan
XY
Yao
Li
L
D017209:Apoptosis; D049109:Cell Proliferation; D015536:Down-Regulation; D015972:Gene Expression Regulation, Neoplastic; D005822:Genetic Vectors; D006801:Humans; D000072181:Inositol Polyphosphate 5-Phosphatases; D020014:K562 Cells; D016086:Lentivirus / Q000235:genetics; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D010744:Phosphoric Monoester Hydrolases / Q000096:biosynthesis* / Q000235:genetics / Q000502:physiology; D010766:Phosphorylation; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction; D014162:Transfection; D018909:src Homology Domains / Q000235:genetics
D012333:RNA, Messenger; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; D010744:Phosphoric Monoester Hydrolases; D000072181:Inositol Polyphosphate 5-Phosphatases