[Frontiers in Bioscience E3, 1483-1492, June 1, 2011]

Garcinol-induced apoptosis in prostate and pancreatic cancer cells is mediated by NF- KappaB signaling

Aamir Ahmad1, Zhiwei Wang1, Christine Wojewoda1, Raza Ali1, Dejuan Kong1, Ma'in Y. Maitah1, Sanjeev Banerjee1, Bin Bao1,Subhash Padhye2, Fazlul H. Sarkar1

1Department of Pathology, Wayne State University School of Medicine and Barbara Ann Karmanos Cancer Center, Detroit, MI 48201, USA, 2ISTRA, Abeda Inamdar College, Pune 411001, India

TABLE OF CONTENTS

1. Abstract
2. Introduction
3. Materials and Methods
3.1. Cell Lines, Reagents, and Antibodies
3.2. Cell Growth Inhibition Studies by MTT Assay
3.3. Cell Viability Studies by Trypan Blue Assay
3.4. Histone/DNA ELISA for Detection of Apoptosis
3.5. Soft Agar Colonization Assays
3.6. Clonogenic Assay
3.7. Western blot assay
3.8. Homogeneous Caspase-3/7 Assay for Apoptosis
3.9. Electrophoretic Mobility Shift Assay (EMSA)
3.10. Data analysis
4. Results
4.1. Garcinol inhibits cell growth of prostate cancer cells
4.2. Garcinol effectively induces apoptosis in prostate cancer cells
4.3. Garcinol inhibits proliferation and induces apoptosis in pancreatic cancer cells
4.4. Effect of Garcinol on the clonogenicity of prostate and pancreatic cancer cells
4.5. Effect of garcinol on NF-kB-DNA binding activity
4.6. Effect of garcinol on NF-kB target genes
5. Discussion
6. References

1. ABSTRACT

Garcinol, obtained from Garcinia indica, is a potent antioxidant. Its anticancer activity has been investigated; however, there is no published report on its action against prostate and pancreatic cancer cells. We have earlier reported its activity against breast cancer cells, and here we tested our hypothesis that garcinol could inhibit cell proliferation and induce apoptosis in prostate as well as pancreatic cancer cells. Using multiple techniques such as MTT, Histone-DNA ELISA, activated caspase assays, clonogenic assays and EMSA, we investigated the mechanism of apoptosis-inducing effect of garcinol in prostate (LNCaP, C4-2B and PC3) and pancreatic (BxPC-3) cancer cells. We found that garcinol inhibited cell growth of all the cell lines tested with a concomitant induction of apoptosis in a dose-dependent manner. Down-regulation of NF- KappaB signaling pathway appears to be the mechanism of apoptosis-induction because garcinol inhibited constitutive levels of NF- BetaB activity, which was consistent with down-regulation of NF- BetaB-regulated genes. A significant decrease in the colony forming ability of all the cell lines was also observed, suggesting the possible application of this compound against metastatic disease. In summary, our results provide pre-clinical evidence to support the use of garcinol against human prostate and pancreatic cancer, thus meriting its further investigation as a potential chemo-preventive and/or therapeutic agent.