The anti-promyelocytic leukemia mode of action of two endophytic secondary metabolites unveiled by a proteomic approach.
As a result of a program to find antitumor compounds of endophytes from medicinal Asteraceae, the steroid (22E,24R)-8,14-epoxyergosta-4,22-diene-3,6-dione (a) and the diterpene aphidicolin (b) were isolated from the filamentous fungi Papulaspora immersa and Nigrospora sphaerica, respectively, and exhibited strong cytotoxicity against HL-60 cells. A proteomic approach was used in an attempt to identify the drugs' molecular targets and their respective antiproliferative mode of action. Results suggested that the (a) growth inhibition effect occurs by G2/M cell cycle arrest via reduction of tubulin alpha and beta isomers and 14-3-3 protein gamma expression, followed by a decrease of apoptotic and inflammatory proteins, culminating in mitochondrial oxidative damage that triggered autophagy-associated cell death. Moreover, the decrease observed in the expression levels of several types of histones indicated that (a) might be disarming oncogenic pathways via direct modulation of the epigenetic machinery. Effects on cell cycle progression and induction of apoptosis caused by (b) were confirmed. In addition, protein expression profiles also revealed that aphidicolin is able to influence microtubule dynamics, modulate proteasome activator complex expression, and control the inflammatory cascade through overexpression of thymosin beta 4, RhoGDI2, and 14-3-3 proteins. Transmission electron micrographs of (b)-treated cells unveiled dose-dependent morphological characteristics of autophagy- or oncosis-like cell death.
Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, PA, USA.
Margareth B C
MB
Gallo
Department of Pharmacology & Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA.
Miranda J S
MJ
Falso
Department of Structural Biology, University of Pittsburgh, Pittsburgh, PA, USA.
Fernanda
F
Balem
Mass Spectrometry Core Facility, Centro de Pesquisas Gonçalo Moniz (CPqGM) - FIOCRUZ, Salvador, BA, Brazil.
Diego
D
Menezes
Núcleo de Biotecnologia e Bioprospecção, Escola Bahiana de Medicina e Saúde Pública, Salvador, BA, Brazil.
Núbia
N
Rocha
Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, PA, USA.
Raghavan
R
Balachandran
Center for Vaccine Research, University of Pittsburgh, Pittsburgh, PA, USA.
Timothy S
TS
Sturgeon
Department of Pharmaceutical Sciences, Faculdade de Ciências Farmacêuticas de Ribeirão Preto - USP, Ribeirão Preto, SP, Brazil.
Mônica T
MT
Pupo
Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, PA, USA.
Billy W
BW
Day
D048948:14-3-3 Proteins / Q000378:metabolism; D000970:Antineoplastic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D016590:Aphidicolin / Q000494:pharmacology* / Q000627:therapeutic use; D019659:Asteraceae / Q000737:chemistry; D001688:Biological Products / Q000494:pharmacology / Q000627:therapeutic use; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D016923:Cell Death; D060026:Endophytes / Q000737:chemistry*; D004875:Ergosterol / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D005658:Fungi / Q000737:chemistry*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D018922:HL-60 Cells; D006801:Humans; D007249:Inflammation / Q000378:metabolism / Q000517:prevention & control; D015473:Leukemia, Promyelocytic, Acute / Q000188:drug therapy / Q000378:metabolism*; D008870:Microtubules / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D018384:Oxidative Stress; D020543:Proteome / Q000378:metabolism*; D040901:Proteomics; D013947:Thymosin / Q000378:metabolism; D014404:Tubulin / Q000378:metabolism; D062949:rho Guanine Nucleotide Dissociation Inhibitor beta / Q000378:metabolism; D000099201:Thymosin beta(4)
D048948:14-3-3 Proteins; D000970:Antineoplastic Agents; D016590:Aphidicolin; D001688:Biological Products; D004875:Ergosterol; D020543:Proteome; D013947:Thymosin; D014404:Tubulin; D062949:rho Guanine Nucleotide Dissociation Inhibitor beta; D000099201:Thymosin beta(4); C557097:8,14-epoxyergosta-4,22-diene-3,6-dione