RESUMEN
Several natural compounds have been found to act as PPARγ agonists, thus regulating numerous biological processes, including the metabolism of carbohydrates and lipids, cell proliferation and differentiation, angiogenesis, and inflammation. Recently, Cladosporols, secondary metabolites purified from the fungus Cladosporium tenuissimum, have been demonstrated to display an efficient ability to control cell proliferation in human colorectal and prostate cancer cells through a PPARγ-mediated modulation of gene expression. In addition, Cladosporols exhibited a strong anti-adipogenetic activity in 3T3-L1 murine preadipocytes, preventing their in vitro differentiation into mature adipocytes. These data interestingly point out that the interaction between Cladosporols and PPARγ, in the milieu of different cells or tissues, might generate a wide range of beneficial effects for the entire organism affected by diabetes, obesity, inflammation, and cancer. This review explores the molecular mechanisms by which the Cladosporol/PPARγ complex may simultaneously interfere with a dysregulated lipid metabolism and cancer promotion and progression, highlighting the potential therapeutic benefits of Cladosporols for human health.
Asunto(s)
PPAR gamma , Animales , Humanos , Ratones , Células 3T3-L1 , Proliferación Celular/efectos de los fármacos , Metabolismo de los Lípidos , PPAR gamma/metabolismoRESUMEN
Two undescribed cladosporol derivatives, cladosporols J-K (1-2), and three previously unreported spirobisnaphthalenes, urnucratins D-F (3-5), as well as eleven known cladosporols (6-16), were characterized from Cladosporium cladosporioides (Cladosporiaceae), a common plant pathogen isolated from the skin of Chinese toad. Cladosporols J-K (1-2) with a single double bond have been rarely reported, while urnucratins D-F (3-5) featured an unusual benzoquinone bisnaphthospiroether skeleton, contributing to an expanding category of undiscovered natural products. Their structures and absolute configurations were determined using extensive spectroscopic methods, including NMR, HRESIMS analyses, X-ray single crystal diffraction, as well as through experimental ECD analyses. Biological assays revealed that compounds 1 and 2 exhibited inhibitory activity against A549 cells, with IC50 values of 30.11 ± 3.29 and 34.32 ± 2.66 µM, respectively.
Asunto(s)
Cladosporium , Naftalenos , Cladosporium/química , Humanos , Naftalenos/química , Naftalenos/aislamiento & purificación , Naftalenos/farmacología , Estructura Molecular , Ensayos de Selección de Medicamentos Antitumorales , Células A549 , Compuestos de Espiro/química , Compuestos de Espiro/aislamiento & purificación , Compuestos de Espiro/farmacología , Relación Estructura-Actividad , Antineoplásicos/farmacología , Antineoplásicos/química , Antineoplásicos/aislamiento & purificación , Relación Dosis-Respuesta a Droga , Proliferación Celular/efectos de los fármacosRESUMEN
OBJECTIVES: Chemoprevention, consisting of the administration of natural and/or synthetic compounds, appears to be an alternative way to common therapeutical approaches to preventing the occurrence of various cancers. Cladosporols, secondary metabolites from Cladosporium tenuissimum, showed a powerful ability in controlling human colon cancer cell proliferation through a peroxisome proliferator-activated receptor gamma (PPARγ)-mediated modulation of gene expression. Hence, we carried out experiments to verify the anticancer properties of cladosporols in human prostate cancer cells. Prostate cancer represents one of the most widespread tumors in which several risk factors play a role in determining its high mortality rate in men. MATERIALS AND METHODS: We assessed, by viability assays, PPARγ silencing and overexpression experiments and western blotting analysis, the anticancer properties of cladosporols in cancer prostate cell lines. RESULTS: Cladosporols A and B selectively inhibited the proliferation of human prostate PNT-1A, LNCaP and PC-3 cells and their most impactful antiproliferative ability towards PC-3 prostate cancer cells, was mediated by PPARγ modulation. Moreover, the anticancer ability of cladosporols implied a sustained apoptosis. Finally, cladosporols negatively regulated the expression of enzymes involved in the biosynthesis of fatty acids and cholesterol, thus enforcing the relationship between prostate cancer development and lipid metabolism dysregulation. CONCLUSION: This is the first work, to our knowledge, in which the role of cladosporols A and B was disclosed in prostate cancer cells. Importantly, the present study highlighted the potential of cladosporols as new therapeutical tools, which, interfering with cell proliferation and lipid pathway dysregulation, may control prostate cancer initiation and progression.
Asunto(s)
Naftalenos , PPAR gamma , Neoplasias de la Próstata , Masculino , Humanos , PPAR gamma/metabolismo , Células PC-3 , Neoplasias de la Próstata/metabolismo , Apoptosis , Proliferación Celular , Lípidos , Línea Celular TumoralRESUMEN
BACKGROUND: Obesity and type 2 diabetes mellitus, which are widespread throughout the world, require therapeutic interventions targeted to solve clinical problems (insulin resistance, hyperglycaemia, dyslipidaemia and steatosis). Several natural compounds are now part of the therapeutic repertoire developed to better manage these pathological conditions. Cladosporols, secondary metabolites from the fungus Cladosporium tenuissimum, have been characterised for their ability to control cell proliferation in human colon cancer cell lines through peroxisome proliferator-activated receptor gamma (PPARγ)-mediated modulation of gene expression. Here, we report data concerning the ability of cladosporols to regulate the differentiation of murine 3T3-L1 preadipocytes. METHODS: Cell counting and MTT assay were used for analysing cell proliferation. RT-PCR and Western blotting assays were performed to evaluate differentiation marker expression. Cell migration was analysed by wound-healing assay. RESULTS: We showed that cladosporol A and B inhibited the storage of lipids in 3T3-L1 mature adipocytes, while their administration did not affect the proliferative ability of preadipocytes. Moreover, both cladosporols downregulated mRNA and protein levels of early (C/EBPα and PPARγ) and late (aP2, LPL, FASN, GLUT-4, adiponectin and leptin) differentiation markers of adipogenesis. Finally, we found that proliferation and migration of HT-29 colorectal cancer cells were inhibited by conditioned medium from cladosporol-treated 3T3-L1 cells compared with the preadipocyte conditioned medium. CONCLUSIONS: To our knowledge, this is the first report describing that cladosporols inhibit in vitro adipogenesis and through this inhibition may interfere with HT-29 cancer cell growth and migration. GENERAL SIGNIFICANCE: Cladosporols are promising tools to inhibit concomitantly adipogenesis and control colon cancer initiation and progression.
Asunto(s)
Naftoles/farmacología , PPAR gamma/agonistas , Células 3T3-L1 , Adipogénesis/efectos de los fármacos , Animales , Proliferación Celular/efectos de los fármacos , Humanos , Ratones , Naftoles/química , Células Tumorales CultivadasRESUMEN
Cladosporols are secondary metabolites from Cladosporium tenuissimum characterized for their ability to control cell proliferation. We previously showed that cladosporol A inhibits proliferation of human colon cancer cells through a PPARγ-mediated modulation of gene expression. In this work, we investigated cladosporol B, an oxidate form of cladosporol A, and demonstrate that it is more efficient in inhibiting HT-29 cell proliferation due to a robust G0/G1-phase arrest and p21(waf1/cip1) overexpression. Cladosporol B acts as a PPARγ partial agonist with lower affinity and reduced transactivation potential in transient transfections as compared to the full agonists cladosporol A and rosiglitazone. Site-specific PPARγ mutants and surface plasmon resonance (SPR) experiments confirm these conclusions. Cladosporol B in addition displays a sustained proapoptotic activity also validated by p21(waf1/cip1) expression analysis in the presence of the selective PPARγ inhibitor GW9662. In the DMSO/H2O system, cladosporols A and B are unstable and convert to the ring-opened compounds 2A and 2B. Finally, docking experiments provide the structural basis for full and partial PPARγ agonism of 2A and 2B, respectively. In summary, we report here, for the first time, the structural characteristics of the binding of cladosporols, two natural molecules, to PPARγ. The binding of compound 2B is endowed with a lower transactivation potential, higher antiproliferative and proapoptotic activity than the two full agonists as compound 2A and rosiglitazone (RGZ).