The growth inhibitory effect of actein on human breast cancer cells is associated with activation of stress response pathways.
Previous studies indicate that the triterpene glycoside actein from the herb black cohosh inhibits growth of human breast cancer cells. This study seeks to identify genes altered in human breast cancer cells by treatment with actein, using gene expression analysis. We treated MDA-MB-453 human breast cancer cells with actein at 2 doses, 20 or 40 microg/mL, for 6 or 24 hr. We identified 5 genes that were activated after each of the treatments that are known to play a role in cellular responses to diverse stresses, including the DNA damage and unfolded protein responses. In addition, four genes that mediate the integrated stress response (ISR), including activating transcription factor 4, were induced under at least one of the 4 treatment conditions. We used hierarchical clustering to define clusters comprising patterns of gene expression. Two ISR genes, activating transcription factor 3 (ATF3) and DNA damage- inducible transcript 3, and lipid biosynthetic genes were activated after exposure to actein at 40 microg/mL for 6 hr, whereas the cell cycle genes cyclin E2 and cell division cycle 25A were repressed. Our results suggest that actein induces 2 phases of the ISR, the survival phase and the apoptotic phase, depending on the dose and duration of treatment. We confirmed the results of gene expression analysis with real-time RT-PCR for 18 selected genes and Western blot analysis for ATF3. Since actein activated transcription factors that enhance apoptosis, and repressed cell cycle genes, it may be useful in the prevention and therapy of breast cancer.
Einbond
Linda Saxe
LS
Department of Rehabilitation Medicine, Columbia University College of Physicians and Surgeons, New York, NY.
Su
Tao
T
Herbert Irving Comprehensive Cancer Center, Columbia University College of Physicians and Surgeons, New York, NY.
Wu
Hsan-Au
HA
Department of Rehabilitation Medicine, Columbia University College of Physicians and Surgeons, New York, NY.
Friedman
Richard
R
Herbert Irving Comprehensive Cancer Center, Columbia University College of Physicians and Surgeons, New York, NY.
Wang
Xiaomei
X
Herbert Irving Comprehensive Cancer Center, Columbia University College of Physicians and Surgeons, New York, NY.
Ramirez
Alejandro
A
Department of Rehabilitation Medicine, Columbia University College of Physicians and Surgeons, New York, NY.
Kronenberg
Fredi
F
Department of Rehabilitation Medicine, Columbia University College of Physicians and Surgeons, New York, NY.
Weinstein
I Bernard
IB
Herbert Irving Comprehensive Cancer Center, Columbia University College of Physicians and Surgeons, New York, NY.
D051700:Activating Transcription Factor 3 / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D002453:Cell Cycle / Q000187:drug effects; D002460:Cell Line; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D051379:Mice; D015394:Molecular Structure; D005810:Multigene Family / Q000235:genetics; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics; D012503:Saponins / Q000737:chemistry / Q000494:pharmacology*; D013997:Time Factors; D014315:Triterpenes / Q000737:chemistry / Q000494:pharmacology*
C490449:ATF3 protein, human; D051700:Activating Transcription Factor 3; D012333:RNA, Messenger; D012503:Saponins; D014315:Triterpenes; C096064:actein