Effect Of Parthenolide Research Articles

Parthenolide attenuates hypoxia-induced pulmonary hypertension through inhibiting STAT3 signaling

BackgroundPulmonary hypertension (PH) is a chronic lung disease characterized by the progressive pulmonary vascular remodeling with increased pulmonary arterial pressure and right ventricular failure. Pulmonary vascular remodeling involves the proliferation, migration, and resistance to apoptosis of pulmonary artery smooth cells (PASMCs). Parthenolide (PTN) is a bioactive compound derived from a traditional medical plant feverfew (Tanacetum parthenium), and it has been studied for treatment of pulmonary fibrosis, lung cancer, and other related ailments. However, the function of PTN in the treatment of PH has not been studied. PurposeThis study aimed to evaluate the anti-proliferation and pro-apoptosis effects of PTN on PH and investigate its potential mechanisms. MethodsAn in vivo hypoxia-induced pulmonary hypertension (HPH) model was established by maintaining male rats in a hypoxia chamber (10% O2) for 3 weeks, and PTN was intraperitoneally administered at the dose of 10 or 30 mg/kg. We assessed the impact of PTN on mean pulmonary arterial pressure (mPAP), pulmonary vascular remodeling, and right ventricular hypertrophy. In vitro, we evaluated hypoxia-induced cellular proliferation, migration, and apoptosis of rat PASMCs. Proteins related to the STAT3 signaling axis were analyzed by western blotting and immunofluorescence assays. Recovery experiments were performed using the STAT3 activator, colivelin TFA. ResultsPTN significantly alleviated the symptoms of HPH rats by attenuating pulmonary arterial remodeling. It also prevented the proliferation and migration of PASMCs. PTN also induced the apoptosis of PASMCs. PTN could directly interact with STAT3 and markedly inhibited STAT3 phosphorylation and nuclear translocation. In vitro, and in vivo experiments demonstrated that overexpression of STAT3 partially suppressed the effect of PTN. ConclusionOur study indicated that PTN alleviated hypoxia-induced pulmonary hypertension in rats by suppressing STAT3 activity.

The protective effect of parthenolide in an in vitro model of Parkinson's disease through its regulation of nuclear factor-kappa B and oxidative stress.

Parkinson's disease (PD) is a neurodegenerative disorder characterized by motor and non-motor symptoms, and is due to the degeneration of dopaminergic neurons. It is multifactorial, caused by genetic and environmental factors and currently has no definitive cure. We have investigated the protective effects of parthenolide (PTN), a compound with known anti-inflammatory and antioxidant properties, in an in vitro model of PD, that is induced by 6-OHDA, and that causes neurotoxicity in SH-SY5Y human neuroblastoma cells. SH-SY5Y cells were pretreated with PTN to assess its protective effects in 6-OHDA-induced cellular damage. Cell viability was measured using Alamar blue. Apoptosis was evaluated using an Annexin V-FITC/PI kit. Reactive oxygen species (ROS) levels were quantified, and expression levels of apoptotic markers (Bax, Bcl-2, p53) and NF-κB were analyzed via Western blotting and Quantitative real-time- (qRT-) PCR. We found that 6-OHDA reduced cell viability, that was inhibited significantly by pre-treatment with PTN (p < 0.05). Flow cytometry revealed that PTN reduced apoptosis induced by 6-OHDA. PTN also reduced the ROS levels raised by 6-OHDA (p < 0.05). Moreover, PTN decreased the expression of Bax, p53, NF-κB, and p-NF-κB that were increased by treatment with 6-OHDA. These findings indicate the potential beneficial effects of PTN in an in vitro model of PD via mitigating oxidative stress and inflammation, suggested PTN as a promising agent to be used for PD therapy, warranting further investigation in preclinical and clinical studies.

Impact of microtubule detyrosination on subcellular distribution of Nav1.5 in mdx cardiomyocytes

Abstract Background Subcellular trafficking and distribution of the cardiac sodium channel Nav1.5 in cardiomyocytes is dependent on the microtubule network as well as Nav1.5 interacting proteins. Duchenne muscular dystrophy (DMD) is associated with loss of dystrophin, a Nav1.5-interacting protein localized at the lateral membrane of cardiomyocytes, leading to sodium current (INa) reduction in this microdomain. Cardiomyocytes of DMD (mdx) mice also display increased microtubule detyrosination, but its impact on INa and Nav1.5 distribution is unclear. Purpose To investigate the effect of reducing microtubule detyrosination by the compound parthenolide (PTL) on INa and subcellular Nav1.5 distribution in mdx cardiomyocytes (CMs). Methods and Results Isolated ventricular CMs from wild type (WT) and mdx (DMD) mice were incubated with either 10 µM PTL or DMSO for 3-5 hours. INa properties were assessed using the patch-clamp technique, confocal microscopy was used to investigate microtubule detyrosination, and stochastic optical reconstruction microscopy (STORM) was employed to assess Nav1.5 cluster density and size, as well as Nav1.5 cluster distribution (crest vs groove) at the cardiomyocyte lateral membrane. Compared to WT. mdx CMs displayed increased levels of detyrosinated tubulin and decreased whole-cell INa. Incubation with PTL decreased the fraction of detyrosinated tubulin and significantly increased whole-cell INa magnitude in mdx CMs, but had no effect in WT CMs. No effect of PTL on INa gating properties were observed, indicating that it increased INa by enhancing Nav1.5 membrane trafficking. Indeed, STORM analysis showed that PTL increased Nav1.5 cluster density at both the lateral membrane and intercalated disc region in mdx CMs while it had no effect on WT CMs. Furthermore, Nav1.5-α-actinin cluster distance analysis showed that PTL increased Nav1.5 clusters specifically at the crest of the lateral membrane in mdx CMs. Conclusions In mdx CMs, reduction of MT detyrosination rescues INa density and increases Nav1.5 cluster density both at the intercalated disc and lateral membrane. Hence, in addition to loss of the Nav1.5-interacting protein dystrophin, MT remodelling contributes to INa reduction in DMD. The PTL-induced increase in Nav1.5 at the crest of the lateral membrane of mdx CMs is likely due to a dystrophin-independent mechanism since dystrophin is normally absent from this microdomain. Overall, our findings identify MT detyrosination as a potential therapeutic target for modulating INa and subcellular Nav1.5 distribution during pathophysiological conditions.

Parthenolide ameliorates neurological deficits and neuroinflammation in mice with traumatic brain injury by suppressing STAT3/NF-κB and inflammasome activation

BackgroundTraumatic brain injury (TBI) triggers a set of complex inflammation that results in secondary injury. Parthenolide (PTN) is a sesquiterpene lactone extracted from the herb Tanacetum parthenium (Feverfew) and has potent anti-inflammatory, anti-apoptosis and anti-oxidative stress effects in the central nervous system (CNS)-related diseases. This study focuses on investigating the potential neuroprotective effect of PTN on TBI and the related mechanism. MethodsBv2 microglia, primary microglia were stimulated by LPS, and HT22 neuron cells were stimulated by OGD/R, and they were treated with different doses of PTN. The expression profiles of pro-inflammatory cytokines, proteins, oxidative stress mediators, STAT3/NF-κB pathway, inflammasomes were detected. Forty male/female C57BL/6 mice were randomly divided into the sham, PTN, TBI, and TBI + PTN groups (10 mice per group). A mouse TBI model was set up with a controlled cortical impact (CCI) device. The modified nerve severity score (mNSS) was implemented to check short-term neurological impairment in mice, and the mice's memory and learning were assessed by the Morris water maze test. The water content in the mice’s brains was measured by the dry-wet method. Hematoxylin-eosin (H&E) staining, Nissl staining and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay were applied for neuronal apoptosis. ResultsPTN dramatically alleviated LPS-induced inflammation in microglia, and OGD-mediated neuronal apoptosis and oxidative stress. In addition, PTN repressed LPS- or OGD-modulated STAT3/NF-κB and NLR family pyrin domain containing 1 (NLRP1), NLRP3, NLR family CARD domain containing 4 (NLRC4) inflammasomes activation. Administering the STAT3 inhibitor Stattic or NF-κB inhibitor Bay 11-7082 attenuated PTN-mediated effects. In vivo, PTN treatment relieved neural function deficits, brain edema and neuron apoptosis and improved the memory and learning function of TBI mice. Additionally, PTN impeded microglial activation and reduced the production of pro-inflammatory cytokines in brain lesions of TBI mice. Furthermore, PTN hindered STAT3/NF-κB and inflammasome activation. ConclusionPTN can curb microglial activation and neuron apoptosis by dampening the STAT3/NF-κB pathway, thus exerting neuroprotective effects in TBI mice.

Effect of parthenolide, an NLRP3 inflammasome inhibitor, on insulin resistance in high-fat diet-obese mice.

The activation of Nod-like receptor proteins (NLRP3) containing the pyrin domain inflammasome is a hallmark of the pathogenesis of metabolic disorders. Inhibition of the NLRP3 inflammasome by phytoconstituents has been attempted as a strategy to mitigate these disorders. Therefore, the present study aimed to evaluate the efficacy of an NLRP3 inflammasome inhibitor, parthenolide (PN; 5mg/kg i.p.) against inflammation and insulin resistance in high-fat diet (HFD) - obese mice. Treatment with PN and pioglitazone (PIO; 30mg/kg p.o.) attenuated lipopolysaccharide (LPS; 1 ng/ml) - induced elevation of tumor necrosis factor-α and interleukin-1β in mouse peritoneal macrophages in a dose-dependent manner. Sixty days of PN and PIO treatment marginally reduced obesity-induced insulin resistance in HFD-obese mice. PN treatment also decreased blood glucose from 14th to 60th day, supporting the hypothesis of simultaneous attenuation of inflammation and insulin resistance in obese mice. Thus, PN treatment was also evident with significant improvement in glucose tolerance and peripheral insulin resistance validated through the respective tolerance tests. Therefore, the present study suggests that PN, an NLRP3 inflammasome inhibitor, could be a possible therapeutic agent for attenuating obesity-induced insulin resistance.

The effect of parthenolide on methamphetamine‐induced blood‐brain barrier and astrocyte alterations

Methamphetamine abuse is a worldwide concern with long-term health complications. Its impact on neurons has been extensively investigated, and it is currently known that glial cells, including astrocytes, are involved in drug-induced outcomes. Importantly, METH also causes blood-brain barrier (BBB) disruption and astrocytes are critical for BBB (dys)function. Therefore, we aimed to clarify the involvement of neuroinflammation mediated by astrocytes in BBB permeability and brain oedema induced by METH. Further, we aimed to identify a new approach to counteract METH effects. Mice were administered with a METH binge regimen (4×10mg/kg) alone or in combination with parthenolide (PTL; 4×1mg/kg), and hippocampi were analysed. For in vitro studies, mouse primary cultures of astrocytes were exposed to 250µM METH, alone or co-treated with 10µM PTL. We observed a neuroinflammatory response characterized by astrocytic morphological changes and increased TNF-α, iNOS and ICAM-1 protein levels (213.62%, 205.76% and 191.47% of control, respectively). Additionally, brain oedema and BBB disruption were identified by increased water content (81.30% of tissue weight) and albumin (224.40% of control) in the hippocampal tissue, as well as a significant decrease in vessel coverage by astrocytes after METH exposure. Regarding astrocyte cultures, we further identified TNF-α as a key player in METH-induced cell swelling. Importantly, PTL (present in feverfew plant) prevented both animal and in vitro effects induced by METH. We provided important insights on brain dysfunction induced by METH, and we also suggest a new approach to counteract such negative effects.

Poster: ALL-015: Stem Cells in Acute Lymphoblastic Leukemia and In Vitro Assessment of the Effect of Parthenolide

Poster: ALL-015: Stem Cells in Acute Lymphoblastic Leukemia and In Vitro Assessment of the Effect of Parthenolide

Parthenolide inhibits the proliferation and induces the apoptosis of human uveal melanoma cells.

To explore the effect of parthenolide (PTL) on human uveal melanoma (UM) cells (C918 and SP6.5 cells) and its molecular mechanism. Carboxyfluorescein succinimidyl amino ester (CFSE) assays and cell counting kit-8 (CCK-8) were performed to detect the cell viability. Flow cytometry was used to analyze cell cycle and apoptosis. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot assays were performed to measure proliferation-related and apoptosis-related factors. Firstly, PTL decreased the viability of C918 and SP6.5 cells in a dose-dependent manner, and the effect of PTL on C918 cells was stronger than on SP6.5; however, it did not affect normal cells. Secondly, PTL increased the proportion of cell number at cell cycle G1 phase in C918 cells, and decreased the proportion of cell number at S phase, but the proportion did not change at G2 phase. In addition, PTL induced the apoptosis of C918 cells, and decreased the expressions of Cyclin D1, B-cell lymphoma-2 (Bcl-2) and B-cell lymphoma-extra large (Bcl-XL). Also, PTL increased Cyclin inhibition protein 1 (P21), Bcl-2-associated X protein (Bax), Cysteinyl aspartate specific proteinas-3 (Caspase-3) and Caspase-9 expression. However, the expression of Caspase-8 was not changed. PTL inhibites proliferation and induces apoptosis in UM cells by arresting G1 phase and regulating mitochondrial pathway, however, it does not affect normal cells.

Parthenolide inhibits lipid accumulation via activation of Nrf2/Keap1 signaling during adipocyte differentiation

The effects of parthenolide (PL), a sesquiterpene lactone obtained from feverfew plant, on lipid accumulation and signaling pathway in adipocytes were investigated. PL significantly inhibited lipid accumulation and adipogenic factors during adipogenesis. In particular, PL exerted its inhibitory effects in early adipogenic stage by regulating the early adipogenic factors. In addition, PL regulated the expression of adipokines; leptin, retinol binding protein, and resistin mRNAs were downregulated, whereas adiponectin gene expression was increased. Furthermore, PL significantly reduced intracellular reactive oxygen species (ROS) production during adipogenesis. This PL-mediated regulation of ROS production was associated with the regulation of nuclear factor erythroid 2-related factor (Nrf2)-kelch-like ECH-associated protein 1 (Keap1) pathway. PL effectively increased the abundance of Nrf2 and its target proteins, heme oxygenase-1 (HO-1) and NADPH dehydrogenase 1 (NQO1), by promoting the nuclear translocation of Nrf2, indicating that PL-mediated anti-adipogenic effects are associated with the Nrf2/Keap1 pathway.

Pharmacological Inhibition of NF\u03baB Reduces Prostate Cancer Related Osteoclastogenesis In Vitro and Osteolysis Ex Vivo

NFκB is implicated in cancer and bone remodelling, and we have recently reported that the verified NFκB inhibitor Parthenolide (PTN) reduced osteolysis and skeletal tumour growth in models of metastatic breast cancer. Here, we took advantage of in vitro and ex vivo bone cell and organ cultures to study the effects of PTN on the ability of prostate cancer cells and their derived factors to regulate bone cell activity and osteolysis. PTN inhibited the in vitro growth of a panel of human, mouse and rat prostate cancer cells in a concentration-dependent manner with a varying degree of potency. In prostate cancer cell—osteoclast co-cultures, the rat Mat-Ly-Lu, but not human PC3 or mouse RM1-BT, enhanced RANKL stimulated osteoclast formation and PTN reduced these effects without affecting prostate cancer cell viability. In the absence of cancer cells, PTN reduced the support of Mat-Ly-Lu conditioned medium for the adhesion and spreading of osteoclast precursors, and survival of mature osteoclasts. Pre-exposure of osteoblasts to PTN prior to the addition of conditioned medium from Mat-Ly-Lu cells suppressed their ability to support the formation of osteoclasts by inhibition of RANKL/OPG ratio. PTN enhanced the ability of Mat-Ly-Lu derived factors to increase calvarial osteoblast differentiation and growth. Ex vivo, PTN enhanced bone volume in calvaria organ—Mat-Ly-Lu cell co-culture, without affecting Mat-Ly-Lu viability or apoptosis. Mechanistic studies in osteoclasts and osteoblasts confirmed that PTN inhibit NFκB activation related to derived factors from Mat-Ly-Lu cells. Collectively, these findings suggest that pharmacological inhibition of the skeletal NFκB signalling pathway reduces prostate cancer related osteolysis, but further studies in the therapeutic implications of NFκB inhibition in cells of the osteoblastic lineage are needed.

Effects of parthenolide on proliferation inhibiting and cell cycle of human renal cancer 786-O cells

Objective To explore the effects of parthenolide on growth inhibition, cell aoptosis and molecular mechanism of human 786-O kidney cancer cells. Methods The inhibitory effect of parthenolide on human786-O cells was determined by MTT assay.The cell apoptosis and the cell cycle were analyzed by flow cytometry.Bax and the gene change of Bax and Bcl-2 were analyzed by fluorescence quantitative PCR, Bax and Bcl-2 family proteins were analyzed by Westerm blot. Results Parthenolide inhibited the proliferation of 786-O cells in a dose-dependent and time-dependent manner.As showed by flow cytometry, parthenolide treatment of the 786-O cells led to significant G1-phase cell cycle arrest in a dose-dependent manner and a decrease in cell population in the S-phase, whereas the population of cells in G2/M phase did not chang significantly.Flow cytometIy also showed a dose-dependent increase in 786-O cells apoptosis by parthenolide treatment.Westem blot analysis indicated a down-regulation of phosphorylated CyclinDl in a dose-dependent manner in 786-O cells by parthenolide treatment.In the gene and protein level, parthenolide treatment to 786-O cell lines resulted a significant reduction in Bcl-2 expression but an increase in Bax protein in a dose-dependent manner. Conclusions Parthenolide treatment can 1ead to a significant dose-dependent and time-dependent inhibition in the growth and an increase in apoptosis of human 786-O Kidney cancer cells.The mechanism of action of parthenolide may be related to inhibition of CyclinDl activation and regulation of Bcl-2 and Bax expression in human 786-O Kidney cancer cells. Key words: Kidney Neoplasms; Tanacetum parthenium; Cell Proliferation; Apoptosis; Cell Cycle

Abstract 129: Parthenolide Inhibits Inflammatory Dysfunction of Human Aortic Endothelial Cells and Proliferation of Smooth Muscle Cells in vitro and Restenosis in a Rat Model

Background: Cardiovascular diseases remain the leading cause of death in developed countries. Endovascular surgical interventions trigger uncontrolled proliferation of smooth muscle cells (SMCs) in the intima (intimal hyperplasia) leading to lumen re-narrowing (restenosis). Despite extensive efforts devoted to therapeutic methods with a focus on inhibiting SMC proliferation, restenosis persists at a significant rate. In recent years, a growing body of knowledge has underscored a crucial role for endothelium damage in the pathophysiology of restenosis, suggesting that preservation of the endothelium would provide an effective approach for effectively curbing restenosis. Methods and Results: We utilized high-throughput screening methods to search for small molecules that could inhibit the proliferation of human aortic SMCs without damaging human aortic endothelial cells (ECs). We identified such a lead compound in Prestwick Library; i.e. Parthenolide, a sesquiterpene lactone extracted from feverfew. Treatment with a low dose (1 μM) of Parthenolide for 96h inhibited SMC but not EC proliferation. When the cells were stimulated with inflammatory cytokines (TNF-α or IL-1β), Parthenolide mitigated cytokine-induced proliferation and MCP-1 production of SMCs, but rescued cytokine-induced endothelial dysfunction, including apoptosis, proliferation, decrease of eNOS, and increase of inflammatory markers. Mechanistic studies showed that while Parthenolide treatment in both SMCs and ECs induced NRF-2 activation (nuclear translocation), NRF-2 knockdown with siRNA diminished the aforementioned beneficial effects of Parthenolide in both cell types. In contrast, NFkB activation was not significantly affected by Parthenolide. In a rat balloon angioplasty model, perivascular delivery of Parthenolide in Pluronic gel effectively inhibited intimal hyperplasia and restenosis 14 days after surgery. Conclusion: These results indicate that the natural compound Parthenolide differentially attenuates pathological behaviors of both human vascular SMCs and ECs, whereas known agents as such are scarce. Thus Parthenolide may serve as a promising lead compound for future development of next-generation anti-restenotic therapeutics.

Hepatoprotective effect of parthenolide in rat model of nonalcoholic fatty liver disease

Context: The active ingredients of traditional medical herbs have been the focus of scientific interests.Objective: This study was designed to explore the mechanisms of actions of parthenolide on nonalcoholic fatty liver disease (NAFLD).Materials and methods: Thirty-five male Wistar rats were fed high-fat diet (HFD) for eight weeks with or without an intraperitoneal injection of parthenolide to develop NAFLD. Liver triacylglycerol (TG), total antioxidant capacity (TAC), total oxidative status (TOS), thiobarbituric acid reactant substances (TBARs), total thiol groups and tumor necrosis factor alpha (TNF-α) and cytochrome P4502E1 (CYP2E1) levels as well as liver ALT, AST and catalase activities were determined. In addition, quantitative real-time PCR was performed to obtain hepatic gene expression levels of TNF-α, CYP2E1 and nuclear factor-κB (NF-κB).Results: HFD caused a significant weight gain and increased liver TG content as well as alteration in ALT and AST activities, which were attenuated after administration of parthenoide (p < .05). Weakened liver antioxidant system (TAC, total thiol groups and catalase activity) and increased oxidative stress markers (TBARs and TOS) were mainly ameliorated by parthenolide treatment (p < .05). Increased hepatic TNF-α, NF-κB and CYP2E1 at the both gene expression and protein levels were found associated with necroinflammatory changes in histopathological observations and were abrogated almost completely after parthenolide treatment. Oxidative and inflammatory changes observed in HFD fed rats were indicative of NAFLD, which were suppressed with parthenolide treatment.Conclusions: Based on these results, parthenolide might be a candidate agent for preventing NAFLD due to its anti-inflammatory and anti-oxidative potency.

Parthenolide suppresses non-small cell lung cancer GLC-82 cells growth via B-Raf/MAPK/Erk pathway

Non-small cell lung cancer (NSCLC), one type of lung cancer, owns high rates of morbidity and mortality. B-Raf is one of the promising oncogenic drivers of NSCLC. Parthenolide, a natural product, is mainly extracted from the herbal plant Tanacetum parthenium. The effect of parthenolide on NSCLC cells and its potential as B-Raf inhibitor were studied in this study. It's shown that parthenolide exhibited the strong cytotoxicity against NSCLC cells with IC50 ranging from 6.07 ± 0.45 to 15.38 ± 1.13 μM. Parthenolide was also able to induce apoptosis, suppress proliferation and invasion in NSCLC cells. In terms of the involved mechanism, parthenolide suppressed GLC-82 cell response via targeting on B-Raf and inhibiting MAPK/Erk pathway signaling. The effect of parthenolide on B-Raf and MAPK/Erk pathway was further confirmed by RNA interference of B-Raf. Decreased expression of c-Myc in protein and mRNA level was also discovered, which is considered as the further downstream of the MAPK/Erk pathway. In addition, STAT3 activity inhibition by parthenolide contributed to its effect on GLC-82 cells, which is independent of PI3K pathway signaling and GSK3. All above provide an insight to understand the action of parthenolide as a potential B-Raf inhibitor in treatment of NSCLC.

Parthenolide Induces Reactive Oxygen Species-Mediated Autophagic Cell Death in Human Osteosarcoma Cells

Background and Aim: Osteosarcoma is a devastating tumor of bone, primarily affecting adolescents. Parthenolide, a naturally occurring small molecule that interferes with NF-κB signaling, has recently attracted considerable attention because of its pharmacological action involving anti-cancer effects. However, the mechanism of the cytotoxic effect exerted by parthenolide on tumor cells is not clearly defined today. Methods: In this study, the effects of parthenolide were evaluated and characterized in human osteosarcoma cancer cell. Cell viability was assessed by CCK-8. Apoptosis was assessed by Annexin V-FITC/PI Flow cytometry assay. Relative quantitative real-time PCR and western blot were used to determine the expressions of genes and proteins. Results: Our results suggest that parthenolide did not cause caspase-dependent cell death in osteosarcoma cancer cells, as indicated by the absence of significant early apoptosis as well as caspase-3 cleavage. Instead, parthenolide increased the autophagy and mitophagy, as characterized by increased PINK1 and Parkin translocation to mitochondria and enhanced autophagy proteins. The induction of autophagy by parthenolide was associated with the increase of reactive oxygen species (ROS). ROS antioxidants N-acetylcysteine (NAC) attenuated parthenolide-induced autophagy activity. Conclusions: Our findings unveil a novel mechanism of drug action by parthenolide in osteosarcoma cancer cells and suggest a potential value of treating osteosarcoma cancer through a caspase-independent autophagic cell death by ROS activation.

Induction of survivin inhibition, G₂/M cell cycle arrest and autophagic on cell death in human malignant glioblastoma cells.

Chemotherapy efficacy is limited by intrinsic and acquired resistance in glioblastoma (GBM); hence, novel tactics are crucial. Survivin has been demonstrated as a key resistant factor in GBM because of its function in inhibiting apoptosis, regulating autophagy, and in promoting G₂/M cell cycle transition. Parthenolide has been reported to be an effective antitumor agent in a variety of tumor cells and decreases survivin level in leukemia cells. But the effect of parthenolide on survivin and the cell death process in GBM is still unknown. The aim of this study was to examine whether parthenolide had the potential to inhibit cell proliferation in the GBM cell line U373. The parthenolide-induced effects in relation to survivin suppression and cell death were further investigated. Our results showed that parthenolide substantially inhibited cell viability with IC₅₀ values of approximate 16 μM. Treatment with parthenolide at the dose of 16 μM led to considerable downregulation of survivin, G₂/M cell cycle arrest and Chk2 upregulation in cells. Parthenolide induced apoptosis in only a few cells and a slight increase in activated caspases 3 levels. By contrast, parthenolide induced a significant increase of intracellular autophagosomes and the expression of autophagy related proteins, including ULK1 and LC3 I/LC3 II, in the treated cells. These results suggested that parthenolide induced survivin inhibition, G₂/M cell cycle arrest, and triggered cell death through autophagic cell death in the GBM cell line.

Nanodelivery of Parthenolide Using Functionalized Nanographene Enhances its Anticancer Activity.

Advances in anticancer chemotherapy have been hindered by the lack of biocompatibility of new prospective drugs. One significant challenge concerns water insolubility, which compromises the bioavailability of the drugs leading to increased dosage and higher systemic toxicity. To overcome these problems, nanodelivery has been established as a promising approach for increasing the efficacy and lowering the required dosage of chemotherapeutics. The naturally derived compound, parthenolide (PTL), is known for its anti-inflammatory and anticancer activity, but its poor water solubility limits its clinical value. In the present study, we have used carboxyl-functionalized nanographene (fGn) delivery to overcome the extreme hydrophobicity of this drug. A water-soluble PTL analog, dimethylamino parthenolide (DMAPT), was also examined for comparison with the anticancer efficacy of our PTL-fGn complex. Delivery by fGn was found to increase the anticancer/apoptotic effects of PTL (but not DMAPT) when delivered to the human pancreatic cancer cell line, Panc-1. The IC50 value for PTL decreased from 39 µM to 9.5 µM when delivered as a mixture with fGn. The IC50 of DMAPT did not decrease when delivered as DMAPT-fGn and was significantly higher than that for PTL-fGn. There were significant increases in ROS formation and in mitochondrial membrane disruption in Panc-1 cells after PTL-fGn treatment as compared to PTL treatment, alone. Increases in toxicity were also seen with apoptosis detection assays using flow cytometry, ethidium bromide/acridine orange/DAPI staining, and TUNEL. Thus, fGn delivery was successfully used to overcome the poor water solubility of PTL, providing a strategy for improving the effectiveness of this anticancer agent.

Chemical Composition and Medicinal Value of the New Ganoderma tsugae var. jannieae CBS-120304 Medicinal Higher Basidiomycete Mushroom.

In this research, the chemical composition and anticancer and antioxidant activity of the new medicinal mushroom Ganoderma tsugae var. jannieae CBS-120304 were evaluated. The chemical composition assay includes amounts of total carbohydrates and proteins, amino acids, fatty acids, micro- and macroelements, and vitamins. The investigated medicinal mushroom seemed to be a rich source of nutritional components. Mycelium accumulated more than 2-fold more total protein compared with the fruiting body and reached 37% and 16% of dry weight, respectively. Carbohydrate content in the fruiting body seemed to be conspicuously higher than in the mycelium (50% of dry weight) and reached 80% of dry weight. Quantification of the identified fatty acids indicated that, in general, palmitic acid, oleic acid, and linoleic acid were the major fatty acids. Toxic elements, such as silver, arsenic, cadmium, and mercury, were found only in trace amounts in mycelium and were not detected in the fruiting body. Furthermore, the 1,1-diphenyl-2-picrylhydrazyl free radical scavenging assay was used to evaluate antioxidant activity. The highest radical scavenging activity was 9.0 mg/mL (65.9%) by ethanol extract. In addition, mycelial extracts were tested to inhibit MCF7 breast cancer cells. Ganoderma tsugae var. jannieae ethyl acetate extract (GTEAE) extract showed high potential by inhibiting reporter activity by more than 70%. Results demonstrated that GTEAE had a strong effect on inhibitory protein κΒα level in the higher concentration used (200 gg/mL), which could be compared with the effect of parthenolide. Furthermore, GTEAE demonstrated strong inhibition of IκΒα phosphorylation.

High-mobility group box 1 up-regulates aquaporin 4 expression via microglia–astrocyte interaction

To clarify the mechanism of high-mobility group box (HMGB) 1-induced brain edema formation, this study focused on the effect of HMGB1 on aquaporin (AQP) 4, a water channel, in rat brain. Treatments for 6h with 100–1000ng/ml HMGB1, not showing self-toxicity, of primary-cultured rat astrocytes didnot increase AQP4 mRNA, unexpectedly. In contrast, intracerebroventricular (i.c.v.) injection of 300ng of HMGB1 significantly increased AQP4 protein after 8h and formed edema after 24h in vivo. Thus, we investigated the roles of microglia as well as astrocytes. HMGB1 (1000ng/ml) drastically increased interleukin (IL)-1β in the primary-cultured rat microglia after 2h. The exposure of microglia to conditioned medium with HMGB1 and 3mM adenosine 5′-triphosphate for 6h significantly increased AQP4 mRNA in astrocytes after 6h. Although 1000ng/ml HMGB1 didnot induce transfer of nuclear factor (NF)-κB into the nucleus in astrocytes after 1h, the conditioned medium containing IL-1β led to its nuclear import. As factors likely to be involved in the nuclear import of NF-κB besides IL-1β, nitric oxide and tumor necrosis factor-α didnot contribute under these conditions. Finally, i.c.v. injection of 30nmol parthenolide, an NF-κB inhibitor, reversed 300ng of HMGB1 injection-induced AQP4 protein increase after 8h in vivo. The effect of parthenolide and the outcomes obtained so far suggest that HMGB1 indirectly up-regulates AQP4 expression through diffusible factor(s) such as IL-1β from microglia since HMGB1 by itself didnot affect NF-κB intracellular localization in astrocytes.

Abstract 3491: Development of a new approach to kill non-small cell lung cancer cells with resistance to standard chemotherapy using parthenolide analogues

Abstract Lung cancer is the leading cause of cancer death in men and women worldwide. The poor prognosis of advanced non-small cell lung cancer (NSCLC) is due, in part, to emergence of tumor resistance to chemotherapy. Recent data indicate that human tumors including NSCLC contain a small subset of cancer stem/ progenitor cells (CSC) responsible for drug resistance and tumor maintenance. If such minute subsets of CSC drive tumor formation and drug resistance, therapies targeting the bulk tumor mass but not CSC will fail. We now confirm identification of subpopulations of chemotherapy-resistant human NSCLC cells with enrichment for CSC biomarkers and exhibiting significant CSC activity. We identified CD133+/ALDH+ tumor stem/progenitor cells from human lung cancer cells in vitro using established Aldefluor assays in combination with labeled anti-CD133 antibodies. Estrogen, a known risk factor for lung cancer progression, stimulated a modest increase in the numbers of CSC. In contrast to control CD133-/ALDH- tumor cell subsets, CSC subpopulations grew as tumor spheres and maintained self-renewal capacity in vitro and exhibited a greater tumorigenic capability than non-CSC subsets in vivo, properties indicative of CSC. Furthermore, resistance of CSC-like cells to cisplatin (a standard chemotherapy for NSCLC treatment) was fully reversed by treatment with parthenolide (PTL), a naturally-occurring sesquiterpene lactone compound with strong antitumor activity in leukemia and prostate cancer while sparing normal cells. The antitumor effect of PTL appears due to its action as a potent inhibitor of nuclear factor-βB (NF-κB) which is markedly activated by chemotherapy. To target CSC and suppress tumor progression, we synthesized and tested novel analogs of PTL with improved antitumor properties and aqueous solubility. PTL analogs inhibit proliferation of H157 NSCLC cells using both bulk cell preparations and CSC-subpopulations, with effects significantly different from control at P&amp;lt;0.05. Dose-dependent increments of PTL analogs increase apoptosis of CSC when compared with bulk cells. Moreover, PTL analogs inhibit cell proliferation of H23, A549 and H1975 NSCLC cells with known resistance to cisplatin (P&amp;lt;0.01). These compounds were able to sensitize cells to cisplatin-induced cytotoxicity (P&amp;lt;0.01) when cells were exposed to sub-optimal concentrations of cisplatin. Using Western blots, we find that PTL congeners inhibit phosphorylation of the p65 subunit of phospho-NF-κB and activation of IKKα/β. Thus, targeted inhibition of NF-κB may reverse tumor drug resistance by interfering with known NF-κB actions to regulate genes involved in proliferation, DNA damage response, antiapoptosis and angiogenesis. Further development of PTL analogs as therapeutics may lead to new strategies to treat NSCLC in the clinic. [Funded by CDMRP Lung Cancer Research Program LC 090297]. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3491. doi:1538-7445.AM2012-3491