Garcinol regulates EMT and Wnt signaling pathways in vitro and in vivo, leading to anticancer activity against breast cancer cells.

Abstract

Anticancer properties of Garcinia indica-derived garcinol are just beginning to be elucidated. We have earlier reported its cancer cell-specific induction of apoptosis in breast cancer cells, which was mediated through the downregulation of NF-κB signaling pathway. To gain further mechanistic insight, here, we show for the first time that garcinol effectively reverses epithelial-to-mesenchymal transition (EMT), that is, it induces mesenchymal-to-epithelial transition (MET) in aggressive triple-negative MDA-MB-231 and BT-549 breast cancer cells. This was associated with upregulation of epithelial marker E-cadherin and downregulation of mesenchymal markers vimentin, ZEB-1, and ZEB-2. We also found that garcinol upregulates the expression of miR-200 and let-7 family microRNAs (miRNAs), which provides a molecular mechanism for the observed reversal of EMT to MET. Transfection of cells with NF-κB p65 subunit attenuated the effect of garcinol on apoptosis induction through reversal of MET to EMT. Forced transfection of p65 and anti-miR-200s could also reverse the inhibitory effect of garcinol on breast cancer cell invasion. Moreover, treatment with garcinol resulted in increased phosphorylation of β-catenin concomitant with its reduced nuclear localization. The results were also validated in vivo in a xenograft mouse model where garcinol was found to inhibit NF-κB, miRNAs, vimentin, and nuclear β-catenin. These novel findings suggest that the anticancer activity of garcinol against aggressive breast cancer cells is, in part, due to reversal of EMT phenotype, which is mechanistically linked with the deregulation of miR-200s, let-7s, NF-κB, and Wnt signaling pathways.

• Authors: Aamir Ahmad, Sanila H Sarkar, Bassam Bitar, Shadan Ali, Amro Aboukameel, Seema Sethi, Yiwei Li, Bin Bao, Dejuan Kong, Sanjeev Banerjee, Subhash B Padhye, Fazlul H Sarkar
• Journal: Molecular cancer therapeutics (Mol Cancer Ther) Vol. 11 Issue 10 Pg. 2193-201 (Oct 2012) ISSN: 1538-8514 [Electronic] United States
• PMID: 22821148 (Publication Type: Journal Article)
• Copyright: ©2012 AACR.

Chemical References

• Antineoplastic Agents
• MicroRNAs
• NF-kappa B
• Terpenes
• garcinol

Topics

• Animals
• Antineoplastic Agents (chemistry, pharmacology, therapeutic use)
• Breast Neoplasms (drug therapy, genetics, metabolism, pathology)
• Cell Line, Tumor
• Dose-Response Relationship, Drug
• Down-Regulation (drug effects, genetics)
• Epithelial-Mesenchymal Transition (drug effects, genetics)
• Female
• Gene Expression Regulation, Neoplastic (drug effects)
• Humans
• Mice
• Mice, SCID
• MicroRNAs (genetics, metabolism)
• NF-kappa B (metabolism)
• Neoplasm Invasiveness
• Terpenes (chemistry, pharmacology, therapeutic use)
• Wnt Signaling Pathway (drug effects, genetics)
• Xenograft Model Antitumor Assays