title: Geranylated 4-Phenylcoumarins Exhibit Anticancer Effects against Human Prostate Cancer Cells through Caspase-Independent Mechanism.
abstract: Geranylated 4-phenylcoumarins, DMDP-1 & -2 isolated from Mesua elegans were investigated for anticancer potential against human prostate cancer cells. Treatment with DMDP-1 & -2 resulted in cell death in a time and dose dependent manner in an MTT assay on all cancer cell lines tested with the exception of lung adenocarcinoma cells. DMDP-1 showed highest cytotoxic efficacy in PC-3 cells while DMDP-2 was most potent in DU 145 cells. Flow cytometry indicated that both coumarins were successful to induce programmed cell death after 24 h treatment. Elucidation on the mode-of-action via protein arrays and western blotting demonstrated death induced without any significant expressions of caspases, Bcl-2 family proteins and cleaved PARP, thus suggesting the involvement of caspase-independent pathways. In identifying autophagy, analysis of GFP-LC3 showed increased punctate in PC-3 cells pre-treated with CQ and treated with DMDP-1. In these cells decreased expression of autophagosome protein, p62 and cathepsin B further confirmed autophagy. In contrary, the DU 145 cells pre-treated with CQ and treated with DMDP-2 has reduced GFP-LC3 punctate although the number of cells with obvious GFP-LC3 puncta was significantly increased in the inhibitor-treated cells. The increase level of p62 suggested leakage of cathepsin B into the cytosol to trigger potential downstream death mediators. This correlated with increased expression of cathepsin B and reduced expression after treatment with its inhibitor, CA074. Also auto-degradation of calpain-2 upon treatment with DMDP-1 &-2 and its inhibitor alone, calpeptin compared with the combination treatment, further confirmed involvement of calpain-2 in PC-3 and DU 145 cells. Treatment with DMDP-1 & -2 also showed up-regulation of total and phosphorylated p53 levels in a time dependent manner. Hence, DMDP-1 & -2 showed ability to activate multiple death pathways involving autophagy, lysosomal and endoplasmic reticulum death proteins which could potentially be manipulated to develop anti-cancer therapy in apoptosis resistant cells.
authors.affiliation: Institute of Biological Science (Genetics & Molecular Biology), Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Noor Shahirah
authors.initials: NS
authors.lastname: Suparji
authors.affiliation: Centre for Natural Product Research and Drug Discovery (CENAR), Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Gomathi
authors.initials: G
authors.lastname: Chan
authors.affiliation: Institute of Biological Science (Genetics & Molecular Biology), Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Hani
authors.initials: H
authors.lastname: Sapili
authors.affiliation: Institute of Biological Science (Genetics & Molecular Biology), Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia.|Centre for Research in Biotechnology for Agriculture (CEBAR), University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Norhafiza M
authors.initials: NM
authors.lastname: Arshad
authors.affiliation: Institute of Biological Science (Genetics & Molecular Biology), Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia.|Department of Biotechnology, Faculty of Applied Sciences, UCSI University, Kuala Lumpur, Malaysia.
authors.forename: Lionel L A
authors.initials: LL
authors.lastname: In
authors.affiliation: Centre for Natural Product Research and Drug Discovery (CENAR), Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Khalijah
authors.initials: K
authors.lastname: Awang
authors.affiliation: Institute of Biological Science (Genetics & Molecular Biology), Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia.|Centre for Research in Biotechnology for Agriculture (CEBAR), University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Noor
authors.initials: N
authors.lastname: Hasima Nagoor
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D001343:Autophagy / Q000187:drug effects; D015153:Blotting, Western; D002154:Calpain / Q000378:metabolism; D020169:Caspases / Q000378:metabolism; D045744:Cell Line, Tumor; D003374:Coumarins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D020128:Inhibitory Concentration 50; D008247:Lysosomes / Q000187:drug effects / Q000378:metabolism; D008297:Male; D011471:Prostatic Neoplasms / Q000201:enzymology* / Q000473:pathology*; D015203:Reproducibility of Results; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D000970:Antineoplastic Agents; D003374:Coumarins; C094411:4-phenylcoumarin; D002154:Calpain; D020169:Caspases