Involvement of NF-kappaB and c-myc signaling pathways in the apoptosis of HL-60 cells induced by alkaloids of Tripterygium hypoglaucum (levl.) Hutch.
Tripterygium hypoglaucum (levl.) Hutch (Celastraceae) (THH) root is a Chinese medicinal herb commonly used for treating autoimmune diseases. In the present study, alkaloids of THH were prepared and their cytotoxicity against the HL-60 cell was investigated. THH-induced apoptosis was observed using flow cytometry, confocal fluorescence microscope, and DNA laddering and caspase assays. The molecular mechanism involved in the induction of HL-60 cell apoptosis by THH alkaloids was examined using cDNA microarrays containing 3000 human genes derived from a leukocyte cDNA library. Sixteen genes were identified to be differentially expressed in HL-60 cells upon THH treatment. Several genes related to the NF-kappaB signaling pathway and cell apoptosis (such as NFKBIB, PRG1 and B2M) were up-regulated. In addition, c-myc binding protein and apoptosis-related cysteine proteases caspase-3 and caspase-8 were also regulated. The changes in c-Myc RNA expression and c-myc protein level were further confirmed by RT-PCR and Western blot analysis. The results demonstrated that THH alkaloids induced apoptosis of HL-60 cells though c-myc and NF-kappaB signaling pathways.
Zhuang
W J
WJ
Department of Biology & Chemistry, City University of Hong Kong, Kowloon, Hong Kong, China.
Fong
C C
CC
Cao
J
J
Ao
L
L
Leung
C H
CH
Cheung
H Y
HY
Xiao
P G
PG
Fong
W F
WF
Yang
M S
MS
D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D004273:DNA, Neoplasm / Q000187:drug effects; D005434:Flow Cytometry; D018922:HL-60 Cells / Q000187:drug effects; D006801:Humans; D018613:Microscopy, Confocal; D016328:NF-kappa B / Q000378:metabolism; D008517:Phytotherapy; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D018517:Plant Roots; D016271:Proto-Oncogene Proteins c-myc / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D029757:Tripterygium
D000972:Antineoplastic Agents, Phytogenic; D004273:DNA, Neoplasm; D016328:NF-kappa B; D010936:Plant Extracts; D016271:Proto-Oncogene Proteins c-myc