[Apoptosis of HL-60 cells induced by crystal proteins from Bacillus thuringiensis Bt9875].
OBJECTIVE
To study the effect of Bt9875 crystal protein treated with proteinase K on human cancer cells, HL-60.


METHODS
We used the methods of Thiazolyl Blue Tetrazolium Bromide, fluorescence microscopy examination, agarose gel electrophores and flow cytometry to detect the growth inhibition rate and apoptosis characters of the HL-60 cells that were treated with different concentration of Bt9875 crystal protein.


RESULTS
Bt9875 crystal protein inhibited the growth of HL-60 cells evidently in a dose-dependent manner, with minimal effects on normal human peripheral blood mononuclear cells (PBMCs). The nuclei of HL-60 cells showed the characteristics of apoptosis. The analysis by flow cytometry indicated that the apoptosis rate of HL-60 cells was 52% after treatment with Bt9875 crystal protein (100 microg/mL). DNA analyzed by agarose gel electrophoresis showed "ladder" pattern.


CONCLUSIONS
Bt9875 crystal protein could inhibit the growth of HL-60 and induced its apoptosis, which provided a foundation for use of Bt9875 crystal protein to cure the acute myeloid leukemia.
Zhu
Lihong
L
Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.
Li
Chong
C
Wu
Ji'an
J
Liang
Ji'angen
J
Shi
Yuefeng
Y
D017209:Apoptosis / Q000187:drug effects*; D001413:Bacillus thuringiensis / Q000737:chemistry* / Q000145:classification / Q000302:isolation & purification; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000302:isolation & purification / Q000494:pharmacology*; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D053938:DNA Fragmentation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D004731:Endotoxins / Q000302:isolation & purification / Q000494:pharmacology*; D005434:Flow Cytometry; D018922:HL-60 Cells; D006460:Hemolysin Proteins / Q000302:isolation & purification / Q000494:pharmacology*; D006801:Humans; D008856:Microscopy, Fluorescence
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis