Zerumbone and small interference RNA induced apoptosis in MCF-7 cell and mammary gland tumor via β-catenin protein inhibition
Extensive research is being conducted to identify therapeutic agents that can inhibit breast cancer cell proliferation through the induction of the apoptotic pathways. Among these is the Wnt/β-catenin pathway, of which β-catenin is one of the main oncogenes of the Wnt signaling pathway implicated...
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Format: | Thesis |
Language: | English |
Published: |
2013
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Subjects: | |
Online Access: | http://psasir.upm.edu.my/id/eprint/67663/1/IB%202013%2042%20IR.pdf |
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Summary: | Extensive research is being conducted to identify therapeutic agents that can inhibit
breast cancer cell proliferation through the induction of the apoptotic pathways.
Among these is the Wnt/β-catenin pathway, of which β-catenin is one of the main
oncogenes of the Wnt signaling pathway implicated in the adhesion of cancer and
non-cancer cells. Several studies have shown that there is close linkage between
Wnt/β-catenin pathways and tumourigenesis and dysregulation with increased cancer
cell growth and survival. In this study, a natural compound, zerumbone (ZER)
extracted from Zingiber zerumbet Smith was chosen as a potential anticancer
compound. The objective of this study is to determine the efficacy of ZER as an
inhibitor of breast cancer progression and the role of β-catenin in its anticancer
effect. This study was conducted both in vitro on MCF-7 cells and in vivo in
Sprague-Dawley rats induced to develop mammary gland tumor with LA7 and/or β-
catenin knockdown LA7 cells. The MCF-7 cells and rats were treated with ZER and
the ZER/β-catenin siRNA combination. β-catenin siRNA was used as a positive
control to specifically inhibit expression and transcriptional activity of β-catenin.
High-throughput screening of 500 apoptosis-related genes of the NFκB and p53
pathways were assessed in treated and untreated MCF-7 cells using the microarray
profiles. The microarray analytical results were confirmed by real-time PCR and
immunocytochemistry. In both the in vitro and in vivo studies, there was good
correlation between β-catenin inhibition and apoptosis. The MTT assay, flow
cytometry, confocal microscopy, and TUNEL assay confirmed that both ZER and
siRNA induced apoptosis in MCF-7 cells while not adversely affecting normal cells.
In the rat model, immunohistochemistry and real-time PCR also showed that ZER
induced apoptosis in mammary gland tumor. The study showed that ZER and β-
catenin siRNA treatments markedly decreased β-catenin-dependent gene expression
and inhibition of MCF-7 cell proliferation. The study also showed the ZER/β-catenin
siRNA combination treatment decreased β-catenin level in vivo. The results of this
study suggest that both ZER and β-catenin siRNA express anticancer activities via
targeting the Wnt/β-catenin signaling pathway. In conclusion, ZER and/or β-catenin
siRNA could be used as potential compounds for the treatment of breast cancers. |
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