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Title: Short-hairpin RNA-mediated Heat shock protein 90 gene silencing inhibits human breast cancer cell growth in vitro and in vivo

Journal Article · · Biochemical and Biophysical Research Communications
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  1. Department of General Surgery, Shanghai 10th People's Hospital, Tongji University School of Medicine, Shanghai 200072 (China)
  2. Department of Nuclear Medicine, Shanghai 10th People's Hospital, Tongji University School of Medicine, Shanghai 200072 (China)
  3. Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, 185 Cambridge Street, Boston, MA 02114 (United States)

Highlights: Black-Right-Pointing-Pointer Hsp90 is over-expressed in human breast cancer. Black-Right-Pointing-Pointer The shRNA-mediated gene silencing of Hsp90 resulted in inhibition of cell growth. Black-Right-Pointing-Pointer Akt and NF-kB were down-regulation after transfection due to Hsp90 silencing. Black-Right-Pointing-Pointer The tumor growth ratio was decline due to Hsp90 silencing. Black-Right-Pointing-Pointer The PCNA expression was down-regulation due to Hsp90 silencing. -- Abstract: Hsp90 interacts with proteins that mediate signaling pathways involved in the regulation of essential processes such as proliferation, cell cycle control, angiogenesis and apoptosis. Hsp90 inhibition is therefore an attractive strategy for blocking abnormal pathways that are crucial for cancer cell growth. In the present study, the role of Hsp90 in human breast cancer MCF-7 cells was examined by stably silencing Hsp90 gene expression with an Hsp90-silencing vector (Hsp90-shRNA). RT-PCR and Western blot analyses showed that Hsp90-shRNA specifically and markedly down-regulated Hsp90 mRNA and protein expression. NF-kB and Akt protein levels were down-regulated in Hsp90-shRNA transfected cells, indicating that Hsp90 knockout caused a reduction of survival factors and induced apoptosis. Treatment with Hsp90-shRNA significantly increased apoptotic cell death and caused cell cycle arrest in the G1/S phase in MCF-7 cells, as shown by flow cytometry. Silencing of Hsp90 also reduced cell viability, as determined by MTT assay. In vivo experiments showed that MCF-7 cells stably transfected with Hsp90-shRNA grew slowly in nude mice as compared with control groups. In summary, the Hsp90-shRNA specifically silenced the Hsp90 gene, and inhibited MCF-7 cell growth in vitro and in vivo. Possible molecular mechanisms underlying the effects of Hsp90-shRNA include the degradation of Hsp90 breast cancer-related client proteins, the inhibition of survival signals and the upregulation of apoptotic pathways. shRNA-mediated interference may have potential therapeutic utility in human breast cancer.

OSTI ID:
22207839
Journal Information:
Biochemical and Biophysical Research Communications, Vol. 421, Issue 2; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0006-291X
Country of Publication:
United States
Language:
English