title: The combination of the prodrugs perforin-CEBPD and perforin-granzyme B efficiently enhances the activation of caspase signaling and kills prostate cancer.
abstract: The survival of prostate cancer (PrCa) patients is associated with the transition to hormone-independent tumor growth and metastasis. Clinically, the dysregulation of androgen action has been associated with the formation of PrCa and the outcome of androgen deprivation therapy in PrCa. CCAAT/enhancer binding protein delta (CEBPD) is a transcription factor that has been reported to act as an oncogene or tumor suppressor, depending on the extra- and intracellular environments following tumorigenesis. We found that androgen can activate CEBPD transcription by direct binding of the androgen receptor (AR) to the CEBPD promoter region. Increases of suppressor of zeste 12 (SUZ12) and enhancer of zeste homolog 2 (EZH2) attenuated the androgen-induced transcription of CEBPD. Importantly, the increases in E2F1, SUZ12 and EZH2 as well as the inactivation of CEBPD were associated with the clinicopathological variables and survival of PrCa patients. We revealed that caspase 8 (CASP8), an apoptotic initiator, is responsive to CEBPD induction. Reporter and in vivo DNA-binding assays revealed that CEBPD directly binds to and activates CASP8 reporter activity. A prodrug system was developed for therapeutic application in AR-independent or androgen-insensitive PrCa to avoid the epigenetic effects on the suppression of CEBPD expression. Our results showed that the combination of a perforin (PF)-CEBPD prodrug (which increases the level of procaspase-8) and a PF-granzyme B prodrug (which activates CASP8 and caspase 3 (CASP3)) showed an additive effect in triggering the apoptotic pathway and enhancing apoptosis in PrCa cells.
authors.affiliation: Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: C-H
authors.initials: CH
authors.lastname: Chuang
authors.affiliation: Institute of Basic Medical Science, National Cheng Kung University, Tainan, Taiwan.
authors.forename: W-J
authors.initials: WJ
authors.lastname: Wang
authors.affiliation: 1] Department of Pathology, Chi-Mei Medical Center, Tainan, Taiwan [2] National Institute of Cancer Research, National Health Research Institutes, Tainan, Taiwan [3] Institute of Clinical Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: C-F
authors.initials: CF
authors.lastname: Li
authors.affiliation: 1] PhD Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan [2] Center for Neurotrauma and Neuroregeneration, Taipei Medical University, Taipei, Taiwan.
authors.forename: C-Y
authors.initials: CY
authors.lastname: Ko
authors.affiliation: Department of Pharmacology, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Y-H
authors.initials: YH
authors.lastname: Chou
authors.affiliation: Institute of Cellular and System Medicine, National Health Research Institutes, Miaoli, Taiwan.
authors.forename: C-P
authors.initials: CP
authors.lastname: Chuu
authors.affiliation: Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: T-L
authors.initials: TL
authors.lastname: Cheng
authors.affiliation: 1] Institute of Bioinformatics and Biosignal Transduction, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan, Taiwan [2] Infectious Disease and Signaling Research Center, National Cheng Kung University, Tainan, Taiwan [3] Center of Molecular Inflammation, National Cheng Kung University, Tainan, Taiwan [4] Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan 
authors.forename: J-M
authors.initials: JM
authors.lastname: Wang
mesh_terms: D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D041702:BALB 3T3 Cells; D001665:Binding Sites; D051743:CCAAT-Enhancer-Binding Protein-delta / Q000494:pharmacology*; D053148:Caspase 3 / Q000378:metabolism*; D053181:Caspase 8 / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D050687:E2F1 Transcription Factor / Q000235:genetics / Q000378:metabolism; D000071221:Enhancer of Zeste Homolog 2 Protein; D004789:Enzyme Activation; D015972:Gene Expression Regulation, Neoplastic; D017930:Genes, Reporter; D053804:Granzymes / Q000494:pharmacology*; D006801:Humans; D008297:Male; D051379:Mice; D009363:Neoplasm Proteins; D054353:Perforin / Q000494:pharmacology*; D063151:Polycomb Repressive Complex 2 / Q000235:genetics / Q000378:metabolism; D011355:Prodrugs / Q000378:metabolism / Q000494:pharmacology*; D011401:Promoter Regions, Genetic; D011471:Prostatic Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D011944:Receptors, Androgen / Q000187:drug effects / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects; D013997:Time Factors; D014157:Transcription Factors; D014162:Transfection
chemical_list: C410798:AR protein, human; D050687:E2F1 Transcription Factor; C493753:E2F1 protein, human; D009363:Neoplasm Proteins; D011355:Prodrugs; D011944:Receptors, Androgen; D011993:Recombinant Fusion Proteins; C430461:SUZ12 protein, human; D014157:Transcription Factors; C000592414:perforin-CEBPD; D054353:Perforin; D051743:CCAAT-Enhancer-Binding Protein-delta; C498409:EZH2 protein, human; D000071221:Enhancer of Zeste Homolog 2 Protein; D063151:Polycomb Repressive Complex 2; D053804:Granzymes; C000592415:perforin-granzyme B; C505407:CASP3 protein, human; C505530:CASP8 protein, human; D053148:Caspase 3; D053181:Caspase 8