Baicalin induces apoptosis in leukemia HL-60/ADR cells via possible down-regulation of the PI3K/Akt signaling pathway.
BACKGROUND
The effect and possible mechanism of traditional Chinese medicine, baicalin, on the PI3K/ Akt signaling pathway in drug-resistant human myeloid leukemia HL-60/ADR cells have been investigated in this current study.


METHODS
HL-60/ADR cells were treated by 20, 40, 80 μmol/L baicalin followed by cell cycle analysis at 24h. The mRNA expression level of the apoptosis related gene, Bcl-2 and bad, were measured by RT-PCR on cells treated with 80 μmol/L baicalin at 12, 24 and 48hr. Western blot was performed to detect the changes in the expression of the proteins related to HL-60/ADR cell apoptosis and the signaling pathway before and after baicalin treatment, including Bcl-2, PARP, Bad, Caspase 3, Akt, p-Akt, NF-κB, p-NF-κB, mTOR and p-mTOR.


RESULTS
Sub-G1 peak of HL-60/ADR cells appeared 24 h after 20 μmol/L baicalin treatment, and the ratio increased as baicalin concentration increased. Cell cycle analysis showed 44.9% G0/G1 phase cells 24 h after baicalin treatment compared to 39.6% in the control group. Cells treated with 80 μmol/L baicalin displayed a trend in decreasing of Bcl-2 mRNA expression over time. Expression level of the Bcl-2 and PARP proteins decreased significantly while that of the PARP, Caspase-3, and Bad proteins gradually increased. No significant difference in Akt expression was observed between treated and the control groups. However, the expression levels of p-Akt, NF-κB, p-NF-κB, mTOR and p-mTOR decreased significantly in a time-dependent manner.


CONCLUSIONS
We conclude that baicalin may induce HL-60/ADR cell apoptosis through the PI3K/AKT signaling pathway.
Fujian Institute of Hematology, Fujian Provincial Key Laboratory on Hematology, Fujian Medical University Union Hospital, Fuzhou, China.
Jing
J
Zheng
Jian-Da
JD
Hu
Ying-Yu
YY
Chen
Bu-Yuan
BY
Chen
Yi
Y
Huang
Zhi-Hong
ZH
Zheng
Ting-Bo
TB
Liu
D017209:Apoptosis / Q000187:drug effects; D053148:Caspase 3 / Q000187:drug effects / Q000378:metabolism; D015536:Down-Regulation / Q000187:drug effects; D019008:Drug Resistance, Neoplasm; D004365:Drugs, Chinese Herbal / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005419:Flavonoids / Q000494:pharmacology*; D016193:G1 Phase; D015870:Gene Expression; D018922:HL-60 Cells; D006801:Humans; D016328:NF-kappa B / Q000187:drug effects / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000187:drug effects / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D011065:Poly(ADP-ribose) Polymerases / Q000187:drug effects / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000187:drug effects / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D016192:Resting Phase, Cell Cycle; D015398:Signal Transduction / Q000187:drug effects*; D058570:TOR Serine-Threonine Kinases / Q000187:drug effects / Q000378:metabolism; D051025:bcl-Associated Death Protein / Q000187:drug effects / Q000235:genetics / Q000378:metabolism
D053148:Caspase 3; D004365:Drugs, Chinese Herbal; D004791:Enzyme Inhibitors; D005419:Flavonoids; D016328:NF-kappa B; D019869:Phosphatidylinositol 3-Kinases; D011065:Poly(ADP-ribose) Polymerases; D051057:Proto-Oncogene Proteins c-akt; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D058570:TOR Serine-Threonine Kinases; D051025:bcl-Associated Death Protein; C494819:BAD protein, human; C038044:baicalin; C546842:MTOR protein, human