Int J Biochem Cell Biol. 2005 Aug;37(8):1709-26. Epub 2005 Apr 26.
Pterostilbene and 3′-hydroxypterostilbene are effective apoptosis-inducing agents in MDR and BCR-ABL-expressing leukemia cells.
Pterostilbene and 3,5-hydroxypterostilbene are the natural 3,5-dimethoxy analogs of trans-resveratrol and piceatannol, two compounds which can induce apoptosis in tumor cells. In previous studies we demonstrated the importance of a 3,5-dimethoxy motif in conferring pro-apoptotic activity to stilbene based compounds so we now wanted to evaluate the ability of pterostilbene and 3,5-hydroxypterostilbene in inducing apoptosis in sensitive and resistant leukemia cells. When tested in sensitive cell lines, HL60 and HUT78, 3′-hydroxypterostilbene was 50-97 times more potent than trans-resveratrol in inducing apoptosis, while pterostilbene appeared barely active. However, both compounds, but not trans-resveratrol and piceatannol, were able to induce apoptosis in the two Fas-ligand resistant lymphoma cell lines, HUT78B1 and HUT78B3, and the multi drug-resistant leukemia cell lines HL60-R and K562-ADR (a Bcr-Abl-expressing cell line resistant to imatinib mesylate). Of note, pterostilbene-induced apoptosis was not inhibited by the pancaspase-inhibitor Z-VAD-fmk, suggesting that this compound acts through a caspase-independent pathway. On the contrary, 3′-hydroxypterostilbene seemed to trigger apoptosis through the intrinsic apoptotic pathway: indeed, it caused a marked disruption of the mitochondrial membrane potential delta psi and its apoptotic effects were inhibited by Z-VAD-fmk and the caspase-9-inhibitor Z-LEHD-fmk. Moreover, pterostilbene and 3′-hydroxypterostilbene, when used at concentrations that elicit significant apoptotic effects in tumor cell lines, did not show any cytotoxicity in normal hemopoietic stem cells. In conclusion, our data show that pterostilbene and particularly 3′-hydroxypterostilbene are interesting antitumor natural compounds that may be useful in the treatment of resistant hematological malignancies, including imatinib, non-responsive neoplasms.
J Toxicol Sci. 2012 Feb;37(1):13-21.
3,5-dibenzyloxy-4′-hydroxystilbene induces early caspase-9 activation during apoptosis in human K562 chronic myelogenous leukemia cells.
A series of 22 stilbene derivatives based on resveratrol were synthesized incorporating acetoxy-, benzyloxy-, carboxy-, chloro-, hydroxy- and methoxy functional groups. We examined the cytotoxicity of these 22 stilbenes in human K562 chronic myelogenous leukemia cells. Only four compounds were cytotoxic namely 4′-hydroxy-3-methoxystilbene (15), 3′-acetoxy-4-chlorostilbene (19), 4′-hydroxy-3,5-dimethoxystilbene or pterostilbene (3) and 3,5-dibenzyloxy-4′-hydroxystilbene (28) with IC(50)s of 78 µM, 38 µM, 67 µM and 19.5 µM respectively. Further apoptosis assessment on the most potent compound, 28, confirmed that the cells underwent apoptosis based on phosphatidylserine externalization and loss of mitochondrial membrane potential. Importantly, we observed a concentration-dependent activation of caspase-9 as early as 2 hr with resultant caspase-3 cleavage in 28-induced apoptosis. Additionally, a structure-activity relationship (SAR) study proposed a possible mechanism of action for compound 28. Taken together, our data suggests that the pro-apoptotic effects of 28 involve the intrinsic mitochondrial pathway characterized by an early activation of caspase-9.
Folia Histochem Cytobiol. 2012;50(4):574-80. doi: 10.5603/20257.
Pterostilbene induces cell cycle arrest and apoptosis in MOLT4 human leukemia cells.
Pterostilbene, a polyphenolic compound present in grapes and other fruits, has been demonstrated to inhibit growth and induce apoptosis and autophagy in some cancer cell types. We found that pterostilbene at the IC(90) concentration of 44 µM inhibited proliferation and induced apoptosis in MOLT4 human leukemia cells. Treatment with pterostilbene resulted in a transient accumulation of cells in the G(0)/G(1)-cell cycle phase followed by the S-phase arrest. Pterostilbene-induced apoptotic death of MOLT4 cells was mediated by caspase-3 activation and was accompanied by the disruption of mitochondrial membrane potential, phosphatidylserine externalization and internucleosomal DNA fragmentation. Our results suggest that pterostilbene could serve as a potential additional chemotherapeutic agent for the treatment of leukemia.
J Physiol Pharmacol. 2013 Oct;64(5):545-56.
Pterostilbene induces accumulation of autophagic vacuoles followed by cell death in HL60 human leukemia cells.
Pterostilbene, a naturally occurring structural analog of resveratrol, has been reported to exert antiproliferative and proapoptotic effects in various cancer types. Recently, it has been demonstrated to induce both autophagy and apoptosis in human bladder and breast cancer cell lines. The aim of this study was to evaluate the effects of pterostilbene on HL60 human leukemia cells. Cell morphology was examined using confocal and electron microscopy. Cell viability was determined by MTT, neutral red uptake and trypan blue exclusion assays. LC3 processing was studied based on Western blotting and immunofluorescence analyses. Flow cytometry was used to study cell cycle distribution, phosphatidylserine externalization, caspase activation, disruption of mitochondrial membrane potential and intracellular production of reactive oxygen species. DNA degradation was examined by gel electrophoresis. We found that treatment of HL60 cells with pterostilbene at the IC90 concentration resulted in the G0/G1 cell cycle arrest. Pterostilbene induced conversion of cytosolic LC3-I to membrane-bound LC3-II and accumulation of large LC3-positive vacuolar structures. Pterostilbene also led to phosphatidylserine externalization, internucleosomal DNA fragmentation, caspase activation and disruption of mitochondrial membrane potential. Moreover, it did not induce oxidative stress. Our results suggest that pterostilbene induces accumulation of autophagic vacuoles followed by cell death in HL60 cells.
PLoS One. 2014 Aug 21;9(8):e105342. doi: 10.1371/journal.pone.0105342. eCollection 2014.
Pterostilbene simultaneously induced G0/G1-phase arrest and MAPK-mediated mitochondrial-derived apoptosis in human acute myeloid leukemia cell lines.
Pterostilbene (PTER) is a dimethylated analog of the phenolic phytoalexin, resveratrol, with higher anticancer activity in various tumors. Herein, the molecular mechanisms by which PTER exerts its anticancer effects against acute myeloid leukemia (AML) cells were investigated.
METHODOLOGY AND PRINCIPAL FINDINGS:
Results showed that PTER suppressed cell proliferation in various AML cell lines. PTER-induced G0/G1-phase arrest occurred when expressions of cyclin D3 and cyclin-dependent kinase (CDK)2/6 were inhibited. PTER-induced cell apoptosis occurred through activation of caspases-8-9/-3, and a mitochondrial membrane permeabilization (MMP)-dependent pathway. Moreover, treatment of HL-60 cells with PTER induced sustained activation of extracellular signal-regulated kinase (ERK)1/2 and c-Jun N-terminal kinase (JNK)1/2, and inhibition of both MAPKs by their specific inhibitors significantly abolished the PTER-induced activation of caspases-8/-9/-3. Of note, PTER-induced cell growth inhibition was only partially reversed by the caspase-3-specific inhibitor, Z-DEVE-FMK, suggesting that this compound may also act through a caspase-independent pathway. Interestingly, we also found that PTER promoted disruption of lysosomal membrane permeabilization (LMP) and release of activated cathepsin B.
Taken together, our results suggest that PTER induced HL-60 cell death via MAPKs-mediated mitochondria apoptosis pathway and loss of LMP might be another cause for cell apoptosis induced by PTER.
Sci Rep. 2016 Nov 21;6:37417. doi: 10.1038/srep37417.
Pterostilbene induces apoptosis and cell cycle arrest in diffuse large B-cell lymphoma cells.
Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma (NHL). Pterostilbene, a natural dimethylated analog of resveratrol, has been shown to possess diverse pharmacological activities, including anti-inflammatory, antioxidant and anticancer properties. However, to the best of our knowledge, there has been no study of the effects of pterostilbene upon hematological malignancies. Herein, we report the antitumor activity and mechanism of pterostilbene against DLBCL cells both in vitro and in vivo. We found that pterostilbene treatment resulted in a dose-dependent inhibition of cell viability. In addition, pterostilbene exhibited a strong cytotoxic effect, as evidenced not only by reductions of mitochondrial membrane potential (MMP) but also by increases in cellular apoptotic index and reactive oxygen species (ROS) levels, leading to arrest in the S-phase of the cell cycle. Furthermore, pterostilbene treatment directly up-regulated p-p38MAPK and down-regulated p-ERK1/2. In vivo, intravenous administration of pterostilbene inhibited tumor development in xenograft mouse models. Overall, the results suggested that pterostilbene is a potential anti-cancer pharmaceutical against human DLBCL by a mechanism involving the suppression of ERK1/2 and activation of p38MAPK signaling pathways.
Int J Mol Sci. 2016 Nov 17;17(11). pii: E1927.
Pterostilbene Inhibits Human Multiple Myeloma Cells via ERK1/2 and JNK Pathway In Vitro and In Vivo.
Multiple myeloma (MM) is the second most common malignancy in the hematologic system, which is characterized by accumulation of plasma cells in bone marrow. Pterostilbene (PTE) is a natural dimethylated analog of resveratrol, which has anti-oxidant, anti-inflammatory and anti-tumor properties. In the present study, we examined the anti-tumor effect of PTE on MM cell lines both in vitro and in vivo using the cell counting kit (CCK)-8, apoptosis assays, cell cycle analysis, reactive oxygen species (ROS) generation, JC-1 mitochondrial membrane potential assay, Western blotting and tumor xenograft models. The results demonstrated that PTE induces apoptosis in the H929 cell line and causes cell cycle arrest at G0/G1 phase by enhancing ROS generation and reducing mitochondrial membrane potential. The anti-tumor effect of PTE may be caused by the activation of the extracellular regulated protein kinases (ERK) 1/2 and c-Jun N-terminal kinase (JNK) signaling pathways. Additionally, mice treated with PTE by intraperitoneal injection demonstrated reduced tumor volume. Taken together, the results of this study indicate that the anti-tumor effect of PTE on MM cells may provide a new therapeutic option for MM patients.
ERK1/2; JNK; apoptosis; cell cycle; multiple myeloma; pterostilbene