ORCID Profile
0000-0002-7779-2697
Current Organisation
University of Adelaide
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Publisher: Medknow
Date: 04-2012
Publisher: American Association for Cancer Research (AACR)
Date: 31-03-2023
DOI: 10.1158/0008-5472.22428967
Abstract: Patient and s le clinical characteristics
Publisher: Springer Science and Business Media LLC
Date: 27-04-2011
Abstract: Angiogenesis, the formation of new blood vessels, has become an important target in cancer therapy. Angiogenesis plays an important role in tumor growth and metastasis. Koetjapic acid (KA) is a seco-A-ring oleanene triterpene isolated from S. koetjape . The solvent extract of this plant species was shown previously to have strong antiangiogenic activity however the active ingredient(s) that conferred the biological activity and the mode of action was not established. Given the high concentration of KA in S. koetjape , an attempt has been made in this study to investigate the antiangiogenic properties of KA. Treatment with 10-50 μg/ml KA resulted in dose dependent inhibition of new blood vessels growth in ex vivo rat aortic ring assay. KA was found to be non-cytotoxic against HUVECs with IC 50 40.97 ± 0.37 μg/ml. KA inhibited major angiogenesis process steps, endothelial cell migration and differentiation as well as VEGF expression. The non-cytotoxic compound, KA, may be a potent antiangiogenic agent its activity may be attributed to inhibition of endothelial cells migration and differentiation as well VEGF suppression.
Publisher: Springer Science and Business Media LLC
Date: 12-2013
Publisher: OMICS Publishing Group
Date: 2018
Publisher: American Association for Cancer Research (AACR)
Date: 31-03-2023
DOI: 10.1158/0008-5472.22428964
Abstract: Results of lipid association analyses
Publisher: Informa UK Limited
Date: 2012
DOI: 10.1080/01635581.2012.630160
Abstract: Cat's whiskers (Orthosiphon stamineus) is commonly used as Java tea to treat kidney stones including a variety of angiogenesis-dependent diseases such as tumorous edema, rheumatism, diabetic blindness, and obesity. In the present study, antitumor potential of standardized 50% ethanol extract of O. stamineus leaves (EOS) was evaluated against colorectal tumor in athymic mice and antiangiogenic efficacy of EOS was investigated in human umbilical vein endothelial cells (HUVEC). EOS at 100 mg/kg caused 47.62 ± 6.4% suppression in tumor growth, while at 200 mg/kg it caused 83.39 ± 4.1% tumor regression. Tumor histology revealed significant reduction in extent of vascularization. Enzyme-linked immunosorbent assay showed EOS (200 mg/kg) significantly reduced the vascular endothelial growth factor (VEGF) level in vitro (211 ± 0.26 pg/ml cell lysate) as well as in vivo (90.9 ± 2 pg/g tissue homogenate) when compared to the control (378 ± 5 and 135.5 ± 4 pg, respectively). However, EOS was found to be noncytotoxic to colon cancer and endothelial cells. In vitro, EOS significantly inhibited the migration and tube formation of human umbilical vein endothelial cells (HUVECs). EOS suppressed VEGF-induced phosphorylation of VEGF receptor-2 in HUVECs. High performance liquid chromatography (HPLC) analysis of EOS showed high rosmarinic acid contents, whereas phytochemical analysis revealed high protein and phenolic contents. These results demonstrated that the antitumor activity of EOS may be due to its VEGF-targeted antiangiogenicity.
Publisher: Spandidos Publications
Date: 30-11-2012
DOI: 10.3892/OR.2011.1569
Abstract: Deregulated cell signaling pathways result in cancer development. More than one signal transduction pathway is involved in colorectal cancer pathogenesis and progression. Koetjapic acid (KA) is a naturally occurring seco-A-ring oleanene triterpene isolated from the Sandoricum koetjape stem bark. We report the cellular and molecular mechanisms of anticancer activity of KA towards human colorectal cancer. The results showed that KA induces apoptosis in HCT 116 colorectal carcinoma cells by inducing the activation of extrinsic and intrinsic caspases. We confirmed that KA-induced apoptosis was mediated by DNA fragmentation, nuclear condensation and disruption in the mitochondrial membrane potential. Further studies on the effect of KA on cancer pathways show that the compound causes down-regulation of Wnt, HIF-1α, MAP/ERK/JNK and Myc/Max signaling pathways and up-regulates the NF-κB signaling pathway. The result of this study highlights the anticancer potential of KA against colorectal cancer.
Publisher: Pharmaceutical Society of Japan
Date: 2012
DOI: 10.1248/BPB.35.503
Abstract: Breast cancer is the most common cancer in women, and it can metastasize very rapidly. Tumor metastasis is the primary cause of cancer deaths. In the present study, we investigated the capability of koetjapic acid, a natural triterpene, in the induction of apoptosis and the inhibition of metastasis in the breast cancer cell line (MCF 7). The effects of koetjapic acid against 4 steps of metastasis have been assessed, including cell survival, clonogenicity, migration and invasion. Koetjapic acid exhibited cytotoxic activity against MCF 7 cells with an IC(50) of 68.88±6.075 μg/mL. The mechanism of cell death was confirmed due to the induction of apoptosis machineries early and late apoptosis-related changes were detected, including the stimulation of caspase 3/7 activities, apoptosis-related morphological changes such as membrane blebbing, chromatin condensation and DNA fragmentation. A mitochondrial apoptosis pathway was found to be involved in koetjapic acid-induced cell death induction. Moreover, at a sub-toxic dose (15 μg/mL), Koetjapic acid inhibited cell migration and invasion significantly. Finally, koetjapic acid inhibited the colony formation properties of MCF 7 significantly. These results indicate that koetjapic acid possesses significant antitumor and antimetastatic effects, and warrants further investigation.
Publisher: Mary Ann Liebert Inc
Date: 12-2013
Publisher: Hindawi Limited
Date: 2014
DOI: 10.1155/2014/396016
Abstract: Cat’s whiskers ( Orthosiphon stamineus ) leaves extracts were prepared using supercritical CO 2 (SC-CO 2 ) with full factorial design to determine the optimum extraction parameters. Nine extracts were obtained by varying pressure, temperature, and time. The extracts were analysed using FTIR, UV-Vis, and GC-MS. Cytotoxicity of the extracts was evaluated on human (colorectal, breast, and prostate) cancer and normal fibroblast cells. Moderate pressure (31.1 MPa) and temperature (60°C) were recorded as optimum extraction conditions with high yield (1.74%) of the extract (B2) at 60 min extraction time. The optimized extract (B2) displayed selective cytotoxicity against prostate cancer (PC3) cells (IC 50 28 µ g/mL) and significant antioxidant activity (IC 50 42.8 µ g/mL). Elevated levels of caspases 3/7 and 9 in B2-treated PC3 cells suggest the induction of apoptosis through nuclear and mitochondrial pathways. Hoechst and rhodamine assays confirmed the nuclear condensation and disruption of mitochondrial membrane potential in the cells. B2 also demonstrated inhibitory effects on motility and colonies of PC3 cells at its subcytotoxic concentrations. It is noteworthy that B2 displayed negligible toxicity against the normal cells. Chemometric analysis revealed high content of essential oils, hydrocarbon, fatty acids, esters, and aromatic sesquiterpenes in B2. This study highlights the therapeutic potentials of SC-CO 2 extract of cat’s whiskers in targeting prostate carcinoma.
Publisher: American Association for Cancer Research (AACR)
Date: 03-04-2023
DOI: 10.1158/1541-7786.C.6540204.V1
Abstract: Abstract Prostate cancer cells exhibit altered cellular metabolism but, notably, not the hallmarks of Warburg metabolism. Prostate cancer cells exhibit increased i de novo /i synthesis of fatty acids (FA) however, little is known about how extracellular FAs, such as those in the circulation, may support prostate cancer progression. Here, we show that increasing FA availability increased intracellular triacylglycerol content in cultured patient-derived tumor explants, LNCaP and C4-2B spheroids, a range of prostate cancer cells (LNCaP, C4-2B, 22Rv1, PC-3), and prostate epithelial cells (PNT1). Extracellular FAs are the major source (∼83%) of carbons to the total lipid pool in all cell lines, compared with glucose (∼13%) and glutamine (∼4%), and FA oxidation rates are greater in prostate cancer cells compared with PNT1 cells, which preferentially partitioned extracellular FAs into triacylglycerols. Because of the higher rates of FA oxidation in C4-2B cells, cells remained viable when challenged by the addition of palmitate to culture media and inhibition of mitochondrial FA oxidation sensitized C4-2B cells to palmitate-induced apoptosis. Whereas in PC-3 cells, palmitate induced apoptosis, which was prevented by pretreatment of PC-3 cells with FAs, and this protective effect required DGAT-1–mediated triacylglycerol synthesis. These outcomes highlight for the first-time heterogeneity of lipid metabolism in prostate cancer cells and the potential influence that obesity-associated dyslipidemia or host circulating has on prostate cancer progression. Implications: Extracellular-derived FAs are primary building blocks for complex lipids and heterogeneity in FA metabolism exists in prostate cancer that can influence tumor cell behavior. /
Publisher: American Association for Cancer Research (AACR)
Date: 03-04-2023
DOI: 10.1158/1541-7786.22526834
Abstract: Figure S1. AUY922 treatment induces the expression of proteins involved in fatty acid. metabolism and increases PCa cell mitochondrial mass and cellular ROS. Figure S2. Combination treatment of AUY922 with antagonists of fatty acid oxidation (FAO) and oxidative phosphorylation reveals functional interactions. Figure S3. AUY922 and PEX act synergistically on PCa cells. Figure S4. AUY922 and PEX act synergistically on PNT1 cells. Figure S5. PEX decreased fatty acid oxidation in AUY922 treated PCa cells. Figure S6. The effect of AUY922 and PEX combination treatment on AKT, ERK and S6 signaling pathways. Figure S7. AUY922 and PEX combination treatment induces apoptosis in 22RV1 and PNT1 cells. Figure S8. AUY922 and PEX combination treatment induces apoptosis in cultured primary prostate tumors.
Publisher: International Union of Crystallography (IUCr)
Date: 08-05-2010
Publisher: Cold Spring Harbor Laboratory
Date: 06-12-2019
DOI: 10.1101/865626
Abstract: Fatty acid β-oxidation (FAO) is the main bioenergetic pathway in prostate cancer (PCa) and a promising novel therapeutic vulnerability. Here we demonstrate therapeutic efficacy of targeting FAO in clinical prostate tumors cultured ex vivo, and identify DECR1, which encodes the rate-limiting enzyme for oxidation of polyunsaturated fatty acids (PUFAs), as robustly overexpressed in PCa tissues and associated with shorter relapse-free survival. DECR1 is a negatively-regulated androgen receptor (AR) target gene and, therefore, may promote PCa cell survival and resistance to AR targeting therapeutics. DECR1 knockdown in PCa cells selectively inhibited β-oxidation of PUFAs, inhibited proliferation and migration of PCa cells, including treatment resistant lines, and suppressed tumor cell proliferation in vivo . Mechanistically, targeting of DECR1 caused cellular accumulation of linoleic acid, enhanced mitochondrial oxidative stress and lipid peroxidation, and ferroptosis. These findings implicate PUFA oxidation via DECR1 as a previously unexplored facet of FAO that promotes survival of PCa cells.
Publisher: American Association for Cancer Research (AACR)
Date: 08-06-2022
DOI: 10.1158/1541-7786.MCR-21-1069
Abstract: Cancer cells feature increased macromolecular biosynthesis to support the formation of new organelles and membranes for cell ision. In particular, lipids are key macromolecules that comprise cellular membrane components, substrates for energy generation and mediators of inter- and intracellular signaling. The emergence of more sensitive and accurate technology for profiling the “lipidome” of cancer cells has led to unprecedented leaps in understanding the complexity of cancer metabolism, but also highlighted promising therapeutic vulnerabilities. Notably, fatty acids, as lipid building blocks, are critical players in all stages of cancer development and progression and the importance of fatty acid desaturation and its impact on cancer cell biology has been well established. Recent years have seen the reports of new mechanistic insights into the role of monounsaturated fatty acids (MUFA) in cancer, as regulators of cell death and lipid-related cellular signaling. This commentary aims to highlight these erse roles of MUFAs in cancer cells which may yield new directions for therapeutic interventions involving these important fatty acids.
Publisher: American Association for Cancer Research (AACR)
Date: 31-03-2023
DOI: 10.1158/0008-5472.22428964.V1
Abstract: Results of lipid association analyses
Publisher: Oxford University Press (OUP)
Date: 14-07-2014
DOI: 10.1111/JPHP.12272
Abstract: Recently, we have isolated koetjapic acid (KA) from Sandoricum koetjape and identified its selective anticancer potentiality against colorectal carcinoma. KA is quite likely to be useful as a systemic anticancer agent against colorectal malignancy. However, with extremely low solubility, KA has to be converted into a biocompatible solubilized form without compromising the bioefficacy. Objective of this study is to enhance solubility of KA and to evaluate anticancer efficacy of potassium koetjapate in human colorectal cancer cells. (2-Hydroxypropyl)-β-cyclodextrin inclusion complex and solid dispersions (carboxymethyl cellulose, polyvinylpyrrolidone and sodium lauryl sulphate) of KA were prepared. In addition, a salt of KA, potassium koetjapate was synthesized. Potassium koetjapate demonstrated higher solubility than the other tested formulations with enhanced cytotoxicity against HCT 116 cells. The enhanced efficacy of potassium koetjapate is attributed to apoptotic induction of nuclear condensation and disruption of mitochondrial membrane potential in the cells. Interestingly, potassium koetjapate was found to be safe in rats after oral administration (LD50 & 2000 mg/kg). The salt formulation of KA appears to modulate the capability of the parent compound by enhancing its solubility and improves its bioefficacy against colon cancer cells, suggesting attractive roles for its applications in medicine.
Publisher: American Association for Cancer Research (AACR)
Date: 05-02-2021
DOI: 10.1158/0008-5472.CAN-20-2511
Abstract: This study identifies phospholipid elongation as a new metabolic target of androgen action that is critical for prostate tumor metastasis.
Publisher: Springer Science and Business Media LLC
Date: 13-08-2013
Abstract: The expression of caveola-forming proteins is dysregulated in prostate cancer. Caveolae are flask-shaped invaginations of the plasma membrane that have roles in membrane trafficking and cell signalling. Members of two families of proteins--caveolins and cavins--are known to be required for the formation and functions of caveolae. Caveolin-1, the major structural protein of caveolae, is overexpresssed in prostate cancer and has been demonstrated to be involved in prostate cancer angiogenesis, growth and metastasis. Polymerase I and transcript release factor (PTRF) is the only cavin family member necessary for caveola formation. When exogenously expressed in prostate cancer cells, PTRF reduces aggressive potential, probably via both caveola-mediated and caveola-independent mechanisms. In addition, stromal PTRF expression decreases with progression of the disease. Evaluation of caveolin-1 antibodies in the clinical setting is underway and it is hoped that future studies will reveal the mechanisms of PTRF action, allowing its targeting for therapeutic purposes.
Publisher: American Association for Cancer Research (AACR)
Date: 03-04-2023
DOI: 10.1158/1541-7786.22512309
Abstract: S1: Pretreatment of PC-3 and C4-2B cells with a FA Mix alters the response to palmitate lipotoxicity and serum-starvation. S2: Dose response assessment of palmitate supplementation on cell viability. S3: Pretreatment with the DGAT1 inhibitor AZD3988 does not affect PC-3 cell growth.
Publisher: Elsevier BV
Date: 07-2020
Publisher: American Association for Cancer Research (AACR)
Date: 31-03-2023
DOI: 10.1158/0008-5472.22429005
Abstract: Supplementary figures 1-9 and legends.
Publisher: American Association for Cancer Research (AACR)
Date: 31-03-2023
DOI: 10.1158/0008-5472.22428970.V1
Abstract: Supplementary Figures S1-S6
Publisher: Science Alert
Date: 15-03-2011
Publisher: American Association for Cancer Research (AACR)
Date: 03-04-2023
DOI: 10.1158/1541-7786.22526831
Abstract: Primary antibodies and stains details
Publisher: American Association for Cancer Research (AACR)
Date: 03-04-2023
DOI: 10.1158/1541-7786.22526831.V1
Abstract: Primary antibodies and stains details
Publisher: Springer Science and Business Media LLC
Date: 04-04-2019
DOI: 10.1007/S11060-019-03161-8
Abstract: Glioblastoma (GBM) is the most common primary brain cancer. The average survival time for the majority of patients is approximately 15 months after diagnosis. A major feature of GBM that contributes to its poor prognosis is its high invasiveness. Caveolae are plasma membrane subdomains that participate in numerous biological functions. Caveolin-1 and Caveolae Associated Protein 1 (CAVIN1), formerly termed Polymerase I and Transcript Release Factor, are both necessary for caveola formation. We hypothesized that high expression of caveola-forming proteins in GBM promotes invasiveness via modulation of the production of matrix-degrading enzymes. The mRNA expression of caveola-forming proteins and matrix proteases in GBM s les, and survival after stratifying patients according to caveolin-1 or CAVIN1 expression, were analyzed from TCGA and REMBRANDT databases. The proteolytic profile of cell lines expressing or devoid of caveola-forming proteins was investigated using zymography and real-time qPCR. Invasion through basement membrane-like protein was investigated in vitro. Expression of both caveolin-1 and CAVIN1 was increased in GBM compared to normal s les and correlated with expression of urokinase plasminogen activator (uPA) and gelatinases. High expression of caveola-forming proteins was associated with shorter survival time. GBM cell lines capable of forming caveolae expressed more uPA and matrix metalloproteinase-2 (MMP-2) and/or -9 (MMP-9) and were more invasive than GBM cells devoid of caveola-forming proteins. Experimental manipulation of caveolin-1 or CAVIN1 expression in GBM cells recapitulated some, but not all of these features. Caveolae modulate GBM cell invasion in part via matrix protease expression.
Publisher: Springer Science and Business Media LLC
Date: 20-10-2014
Publisher: OMICS Publishing Group
Date: 2016
Publisher: African Journals Online (AJOL)
Date: 10-09-2014
Publisher: American Association for Cancer Research (AACR)
Date: 03-04-2023
DOI: 10.1158/1541-7786.22526825
Abstract: Supplementary Data Table
Publisher: Springer Science and Business Media LLC
Date: 12-08-2016
DOI: 10.1038/SREP31572
Abstract: Interactions between the various cell types that constitute a solid tumour are essential to the biology of the tumour. We evaluated the effect of morphine on the proangiogenic interaction taking place between macrophages and breast cancer cells in vitro . The conditioned medium (CM) from breast cancer cells co-cultured with macrophages elicited endothelial cell proliferation and tube formation. This effect was inhibited if the co-culture occurred in the presence of morphine. The CM from breast cancer cells or macrophages grown in idually, whether or not prepared in the presence of morphine, was ineffective in stimulating EC proliferation or tube formation. Using a mouse antibody array, we identified several angiogenesis-regulating factors differentially expressed in the CM of co-cultured cells prepared in the presence or absence of morphine, amongst which interleukin (IL)-6, tumour necrosis factor (TNF)-α and vascular endothelial growth factor (VEGF)-A. VEGF was induced in both cell types by the co-culture and this was prevented by morphine in a non-naloxone reversible fashion. The effect of CM from co-cultured cells on endothelial tube formation, but not proliferation, was prevented by anti-VEGF neutralizing antibody. Our results indicate that morphine prevents, in part via modulating VEGF-A expression, the pro-angiogenic interaction between macrophages and breast cancer cells.
Publisher: American Association for Cancer Research (AACR)
Date: 03-04-2023
DOI: 10.1158/1541-7786.22526822
Abstract: Clinicopathological features of prostate cancer patients in the study
Publisher: Elsevier
Date: 2015
DOI: 10.1016/BS.IRCMB.2015.07.009
Abstract: Caveolae are specialized small plasma-membrane invaginations that play crucial cellular functions. Two essential protein families are required for caveola formation: membrane caveolin proteins and cytoplasmic cavin proteins. Each family includes members with specific tissue distribution, and their expression is altered under physiological and pathological conditions, implying highly specialized functions. Cavins not only stabilize caveolae, but modulate their morphology and functions as well. Before association with the plasma membrane, cavins form homo- and hetero-oligomers with strikingly strict stoichiometry in the cytosol. At the plasma membrane, they provide an outer peripheral cytosolic layer, necessary for caveola stability. Interestingly, upon stimulation, cavins can be released from caveolae into the cytoplasm in distinct subcomplexes, providing a rapid dynamic link between caveolae and cellular organelles including the nucleus. In this review, we detail the biology of cavins, their structural and functional roles, and their implication in pathophysiology.
Publisher: American Association for Cancer Research (AACR)
Date: 03-04-2023
DOI: 10.1158/1541-7786.22526828
Abstract: Primer sequences
Publisher: American Association for Cancer Research (AACR)
Date: 10-2020
DOI: 10.1158/1541-7786.MCR-20-0570
Abstract: Metabolic pathways induced in tumor cells by therapeutic agents may be critical, but targetable, mediators of treatment resistance.
Publisher: Springer Science and Business Media LLC
Date: 05-11-2012
Publisher: American Association for Cancer Research (AACR)
Date: 31-03-2023
DOI: 10.1158/0008-5472.C.6513210.V1
Abstract: Abstract The androgen receptor (AR) is the key oncogenic driver of prostate cancer, and despite implementation of novel AR targeting therapies, outcomes for metastatic disease remain dismal. There is an urgent need to better understand androgen-regulated cellular processes to more effectively target the AR dependence of prostate cancer cells through new therapeutic vulnerabilities. Transcriptomic studies have consistently identified lipid metabolism as a hallmark of enhanced AR signaling in prostate cancer, yet the relationship between AR and the lipidome remains undefined. Using mass spectrometry–based lipidomics, this study reveals increased fatty acyl chain length in phospholipids from prostate cancer cells and patient-derived explants as one of the most striking androgen-regulated changes to lipid metabolism. Potent and direct AR-mediated induction of ELOVL fatty acid elongase 5 (ELOVL5), an enzyme that catalyzes fatty acid elongation, was demonstrated in prostate cancer cells, xenografts, and clinical tumors. Assessment of mRNA and protein in large-scale data sets revealed ELOVL5 as the predominant ELOVL expressed and upregulated in prostate cancer compared with nonmalignant prostate. ELOVL5 depletion markedly altered mitochondrial morphology and function, leading to excess generation of reactive oxygen species and resulting in suppression of prostate cancer cell proliferation, 3D growth, and i in vivo /i tumor growth and metastasis. Supplementation with the monounsaturated fatty acid cis-vaccenic acid, a direct product of ELOVL5 elongation, reversed the oxidative stress and associated cell proliferation and migration effects of ELOVL5 knockdown. Collectively, these results identify lipid elongation as a protumorigenic metabolic pathway in prostate cancer that is androgen-regulated, critical for metastasis, and targetable via ELOVL5. Significance: This study identifies phospholipid elongation as a new metabolic target of androgen action that is critical for prostate tumor metastasis. /
Publisher: American Association for Cancer Research (AACR)
Date: 03-04-2023
DOI: 10.1158/1541-7786.22526828.V1
Abstract: Primer sequences
Publisher: American Association for Cancer Research (AACR)
Date: 31-03-2023
DOI: 10.1158/0008-5472.C.6513199.V1
Abstract: Abstract Dysregulated lipid metabolism is a prominent feature of prostate cancer that is driven by androgen receptor (AR) signaling. Here we used quantitative mass spectrometry to define the “lipidome” in prostate tumors with matched benign tissues ( i n /i = 21), independent unmatched tissues ( i n /i = 47), and primary prostate explants cultured with the clinical AR antagonist enzalutamide ( i n /i = 43). Significant differences in lipid composition were detected and spatially visualized in tumors compared with matched benign s les. Notably, tumors featured higher proportions of monounsaturated lipids overall and elongated fatty acid chains in phosphatidylinositol and phosphatidylserine lipids. Significant associations between lipid profile and malignancy were validated in unmatched s les, and phospholipid composition was characteristically altered in patient tissues that responded to AR inhibition. Importantly, targeting tumor-related lipid features via inhibition of acetyl-CoA carboxylase 1 significantly reduced cellular proliferation and induced apoptosis in tissue explants. This characterization of the prostate cancer lipidome in clinical tissues reveals enhanced fatty acid synthesis, elongation, and desaturation as tumor-defining features, with potential for therapeutic targeting. Significance: This study identifies malignancy and treatment-associated changes in lipid composition of clinical prostate cancer tissues, suggesting that mediators of these lipidomic changes could be targeted using existing metabolic agents. /
Publisher: American Association for Cancer Research (AACR)
Date: 03-04-2023
DOI: 10.1158/1541-7786.C.6545228.V1
Abstract: Abstract HSP90 is a molecular chaperone required for stabilization and activation of hundreds of client proteins, including many known oncoproteins. AUY922 (luminespib), a new-generation HSP90 inhibitor, exhibits potent preclinical efficacy against several cancer types including prostate cancer. However, clinical use of HSP90 inhibitors for prostate cancer has been limited by toxicity and treatment resistance. Here, we aimed to design an effective combinatorial therapeutic regimen that utilizes subtoxic doses of AUY922, by identifying potential survival pathways induced by AUY922 in clinical prostate tumors. We conducted a proteomic analysis of 30 patient-derived explants (PDE) cultured in the absence and presence of AUY922, using quantitative mass spectrometry. AUY922 significantly increased the abundance of proteins involved in oxidative phosphorylation and fatty acid metabolism in the PDEs. Consistent with these findings, AUY922-treated prostate cancer cell lines exhibited increased mitochondrial mass and activated fatty acid metabolism processes. We hypothesized that activation of fatty acid oxidation is a potential adaptive response to AUY922 treatment and that cotargeting this process will sensitize prostate cancer cells to HSP90 inhibition. Combination treatment of AUY922 with a clinical inhibitor of fatty acid oxidation, perhexiline, synergistically decreased viability of several prostate cancer cell lines, and had significant efficacy in PDEs. The novel drug combination treatment induced cell-cycle arrest and apoptosis, and attenuated the heat shock response, a known mediator of HSP90 treatment resistance. This combination warrants further preclinical and clinical investigation as a novel strategy to overcome resistance to HSP90 inhibition. Implications: Metabolic pathways induced in tumor cells by therapeutic agents may be critical, but targetable, mediators of treatment resistance. /
Publisher: Springer Science and Business Media LLC
Date: 02-2018
DOI: 10.1038/S41598-018-19871-4
Abstract: The molecular chaperone Hsp90 is overexpressed in prostate cancer (PCa) and is responsible for the folding, stabilization and maturation of multiple oncoproteins, which are implicated in PCa progression. Compared to first-in-class Hsp90 inhibitors such as 17-allylamino-demethoxygeldanamycin (17-AAG) that were clinically ineffective, second generation inhibitor AUY922 has greater solubility and efficacy. Here, transcriptomic and proteomic analyses of patient-derived PCa explants identified cytoskeletal organization as highly enriched with AUY922 treatment. Validation in PCa cell lines revealed that AUY922 caused marked alterations to cell morphology, and suppressed cell motility and invasion compared to vehicle or 17-AAG, concomitant with dysregulation of key extracellular matrix proteins such as fibronectin (FN1). Interestingly, while the expression of FN1 was increased by AUY922, FN1 secretion was significantly decreased. This resulted in cytosolic accumulation of FN1 protein within late endosomes, suggesting that AUY922 disrupts vesicular secretory trafficking pathways. Depletion of FN1 by siRNA knockdown markedly reduced the invasive capacity of PCa cells, phenocopying AUY922. These results highlight a novel mechanism of action for AUY922 beyond its established effects on cellular mitosis and survival and, furthermore, identifies extracellular matrix cargo delivery as a potential therapeutic target for the treatment of aggressive PCa.
Publisher: American Association for Cancer Research (AACR)
Date: 31-03-2023
DOI: 10.1158/0008-5472.22428967.V1
Abstract: Patient and s le clinical characteristics
Publisher: American Association for Cancer Research (AACR)
Date: 03-04-2023
DOI: 10.1158/1541-7786.22526834.V1
Abstract: Figure S1. AUY922 treatment induces the expression of proteins involved in fatty acid. metabolism and increases PCa cell mitochondrial mass and cellular ROS. Figure S2. Combination treatment of AUY922 with antagonists of fatty acid oxidation (FAO) and oxidative phosphorylation reveals functional interactions. Figure S3. AUY922 and PEX act synergistically on PCa cells. Figure S4. AUY922 and PEX act synergistically on PNT1 cells. Figure S5. PEX decreased fatty acid oxidation in AUY922 treated PCa cells. Figure S6. The effect of AUY922 and PEX combination treatment on AKT, ERK and S6 signaling pathways. Figure S7. AUY922 and PEX combination treatment induces apoptosis in 22RV1 and PNT1 cells. Figure S8. AUY922 and PEX combination treatment induces apoptosis in cultured primary prostate tumors.
Publisher: Wiley
Date: 26-03-2018
DOI: 10.1111/BJU.14173
Abstract: Emerging data have linked certain features of clinical prostate cancer (PCa) to obesity and, more specifically, increased adiposity. Whereas the large number of clinical studies and meta-analyses that have explored the associations between PCa and obesity have shown considerable variability, particularly in relation to prostate cancer risk, there is an accumulating weight of evidence consistently linking obesity to greater aggressiveness of disease. In probing this association mechanistically, it has been posited that peri-prostatic adipose tissue (PPAT), a significant component of the prostate microenvironment, may be a critical source of fatty acids and other mitogens and thereby influences PCa pathogenesis and progression. Notably, several recent studies have identified secreted factors from both PPAT and PCa that potentially mediate the two-way communication between these intimately linked tissues. In the present review, we summarize the available literature regarding the relationship between PPAT and PCa, including the potential biological mediators of that relationship, and explore emerging areas of interest for future research endeavours.
Publisher: Elsevier BV
Date: 12-2017
DOI: 10.1016/J.COMPBIOLCHEM.2017.10.003
Abstract: Platelet derived growth factor beta receptor (PDGFR- β) plays an important role in angiogenesis. PDGFR-β expression is correlated with increased vascularity and maturation of blood vessels in cancer. Pharmacophore modeling and quantitative structure-activity relationship (QSAR) analysis were combined to explore the structural requirements for ligand-PDGFR-β recognition using 107 known PDGFR-β inhibitors. Genetic function algorithm (GFA) coupled to k nearest neighbor (kNN) and multiple linear regression (MLR) analysis were employed to generate predictive QSAR models based on optimal combinations of pharmacophores and physicochemical descriptors. The successful pharmacophores were complemented with exclusion spheres to optimize their receiver operating characteristic curve (ROC) profiles. The QSAR models and their associated pharmacophore hypotheses were validated by identification and experimental evaluation of new angiogenesis inhibitory leads retrieved from the National Cancer Institute (NCI) structural database. Two hits illustrated low micromolar IC
Publisher: Medknow
Date: 08-2017
Publisher: American Association for Cancer Research (AACR)
Date: 31-03-2023
DOI: 10.1158/0008-5472.22429005.V1
Abstract: Supplementary figures 1-9 and legends.
Publisher: American Association for Cancer Research (AACR)
Date: 04-2019
DOI: 10.1158/1541-7786.MCR-18-0347
Abstract: Extracellular-derived FAs are primary building blocks for complex lipids and heterogeneity in FA metabolism exists in prostate cancer that can influence tumor cell behavior.
Publisher: American Association for Cancer Research (AACR)
Date: 03-04-2023
DOI: 10.1158/1541-7786.C.6545228
Abstract: Abstract HSP90 is a molecular chaperone required for stabilization and activation of hundreds of client proteins, including many known oncoproteins. AUY922 (luminespib), a new-generation HSP90 inhibitor, exhibits potent preclinical efficacy against several cancer types including prostate cancer. However, clinical use of HSP90 inhibitors for prostate cancer has been limited by toxicity and treatment resistance. Here, we aimed to design an effective combinatorial therapeutic regimen that utilizes subtoxic doses of AUY922, by identifying potential survival pathways induced by AUY922 in clinical prostate tumors. We conducted a proteomic analysis of 30 patient-derived explants (PDE) cultured in the absence and presence of AUY922, using quantitative mass spectrometry. AUY922 significantly increased the abundance of proteins involved in oxidative phosphorylation and fatty acid metabolism in the PDEs. Consistent with these findings, AUY922-treated prostate cancer cell lines exhibited increased mitochondrial mass and activated fatty acid metabolism processes. We hypothesized that activation of fatty acid oxidation is a potential adaptive response to AUY922 treatment and that cotargeting this process will sensitize prostate cancer cells to HSP90 inhibition. Combination treatment of AUY922 with a clinical inhibitor of fatty acid oxidation, perhexiline, synergistically decreased viability of several prostate cancer cell lines, and had significant efficacy in PDEs. The novel drug combination treatment induced cell-cycle arrest and apoptosis, and attenuated the heat shock response, a known mediator of HSP90 treatment resistance. This combination warrants further preclinical and clinical investigation as a novel strategy to overcome resistance to HSP90 inhibition. Implications: Metabolic pathways induced in tumor cells by therapeutic agents may be critical, but targetable, mediators of treatment resistance. /
Publisher: American Association for Cancer Research (AACR)
Date: 03-04-2023
DOI: 10.1158/1541-7786.22526825.V1
Abstract: Supplementary Data Table
Publisher: eLife Sciences Publications, Ltd
Date: 15-07-2020
Publisher: Wiley
Date: 17-02-2020
DOI: 10.1111/JCMM.15076
Publisher: Impact Journals, LLC
Date: 03-08-2015
Abstract: Lymphangiogenesis allows prostate cancer (PCa) lymphatic metastasis, which is associated with poor prognosis and short survival rates. Caveolin-1 (Cav-1) is a membrane protein localized in caveolae, but also exists in non-caveolar, cellular or extracellular forms. Cav-1 is overexpressed in PCa, promotes prostate tumour progression and metastasis. We investigated the effect of caveolar and non-caveolar Cav-1 on PCa lymphangiogenic potential. Cav-1 was down-regulated in PC3 and DU145, and ectopically expressed in LNCaP cells. The effect of PCa cell conditioned media on lymphatic endothelial cell (LEC) viability, chemotaxis, chemokinesis and differentiation was assessed. The effect of Cav-1 on PCa cell expression of lymphangiogenesis-modulators VEGF-A and VEGF-C was assessed using qPCR and ELISA of the conditioned medium. Non-caveolar Cav-1, whether exogenous or endogenous (in LNCaP and PC3 cells, respectively) enhanced LEC proliferation, migration and differentiation. In contrast, caveolar Cav-1 (in DU145 cells) did not significantly affect PCa cell lymphangiogenic potential. The effect of non-caveolar Cav-1 on LECs was mediated by increased expression of VEGF-A as demonstrated by neutralization by anti-VEGF-A antibody. This study unveils for the first time a crucial role for non-caveolar Cav-1 in modulating PCa cell expression of VEGF-A and subsequent LEC proliferation, migration and tube formation.
Publisher: eLife Sciences Publications, Ltd
Date: 20-07-2020
DOI: 10.7554/ELIFE.54166
Abstract: Fatty acid β-oxidation (FAO) is the main bioenergetic pathway in human prostate cancer (PCa) and a promising novel therapeutic vulnerability. Here we demonstrate therapeutic efficacy of targeting FAO in clinical prostate tumors cultured ex vivo, and identify DECR1, encoding the rate-limiting enzyme for oxidation of polyunsaturated fatty acids (PUFAs), as robustly overexpressed in PCa tissues and associated with shorter relapse-free survival. DECR1 is a negatively-regulated androgen receptor (AR) target gene and, therefore, may promote PCa cell survival and resistance to AR targeting therapeutics. DECR1 knockdown selectively inhibited β-oxidation of PUFAs, inhibited proliferation and migration of PCa cells, including treatment resistant lines, and suppressed tumor cell proliferation and metastasis in mouse xenograft models. Mechanistically, targeting of DECR1 caused cellular accumulation of PUFAs, enhanced mitochondrial oxidative stress and lipid peroxidation, and induced ferroptosis. These findings implicate PUFA oxidation via DECR1 as an unexplored facet of FAO that promotes survival of PCa cells.
Publisher: American Association for Cancer Research (AACR)
Date: 06-08-2021
DOI: 10.1158/0008-5472.CAN-20-3863
Abstract: This study identifies malignancy and treatment-associated changes in lipid composition of clinical prostate cancer tissues, suggesting that mediators of these lipidomic changes could be targeted using existing metabolic agents.
Publisher: Springer Science and Business Media LLC
Date: 12-2011
Publisher: Wiley
Date: 16-08-2016
DOI: 10.1002/PROS.23239
Abstract: While there is compelling rationale to use heat shock protein 90 (Hsp90) inhibitors for treatment of advanced prostate cancer, agents that target the N-terminal ATP-binding site of Hsp90 have shown little clinical benefit. These N-terminal binding agents induce a heat shock response that activates compensatory heat shock proteins, which is believed to contribute in part to the agents' lack of efficacy. Here, we describe the functional characterization of two novel agents, SM253 and SM258, that bind the N-middle linker region of Hsp90, resulting in reduced client protein activation and preventing C-terminal co-chaperones and client proteins from binding to Hsp90. Inhibition of Hsp90 activity in prostate cancer cells by SM253 and SM 258 was assessed by pull-down assays. Cell viability, proliferation and apoptosis were assayed in prostate cancer cell lines (LNCaP, 22Rv1, PC-3) cultured with N-terminal Hsp90 inhibitors (AUY922, 17-AAG), SM253 or SM258. Expression of HSR heat shock proteins, Hsp90 client proteins and co-chaperones was assessed by immunoblotting. Efficacy of the SM compounds was evaluated in human primary prostate tumors cultured ex vivo by immunohistochemical detection of Hsp70 and Ki67. SM253 and SM258 exhibit antiproliferative and pro-apoptotic activity in multiple prostate cancer cell lines (LNCaP, 22Rv1, and PC-3) at low micromolar concentrations. Unlike the N-terminal inhibitors AUY922 and 17-AAG, these SM agents do not induce expression of Hsp27, Hsp40, or Hsp70, proteins that are characteristic of the heat shock response, in any of the prostate cell lines analyzed. Notably, SM258 significantly reduced proliferation within 2 days in human primary prostate tumors cultured ex vivo, without the significant induction of Hsp70 that was caused by AUY922 in the tissues. Our findings provide the first evidence of efficacy of this class of C-terminal modulators of Hsp90 in human prostate tumors, and indicate that further evaluation of these promising new agents is warranted. Prostate 76:1546-1559, 2016. © 2016 Wiley Periodicals, Inc.
Publisher: American Association for Cancer Research (AACR)
Date: 31-03-2023
DOI: 10.1158/0008-5472.22428970
Abstract: Supplementary Figures S1-S6
Publisher: American Association for Cancer Research (AACR)
Date: 14-05-2018
DOI: 10.1158/1078-0432.CCR-18-0172
Abstract: Purpose: The purpose of this study is to investigate the potential interplay between opioid analgesia and tumor metastasis through modulation of μ-opioid receptor (MOR), Toll-like receptor 4 (TLR4) activation, and matrix degradation potential. Experimental Design: Plasma s les were collected from 60 patients undergoing elective lower limb joint replacement preoperatively and at 3, 6, and 24 hours after surgery pain scores were documented at the same time points. Opioid administration was recorded and converted into morphine IV equivalents. Plasma s les were also collected from 10 healthy volunteers. Alphascreen cyclic AMP assay and MOR-overexpressing cells were employed to quantify MOR activation. HEK-Blue hTLR4 were utilized to measure TLR4 activation. Circulating matrix metalloprotease and tissue inhibitor of matrix protease activities were assessed by gelatin zymography and reverse zymography, respectively. Results: Postoperative plasma s les displayed the ability to activate MOR and to inhibit lipopolysaccharide (LPS)-induced TLR4 activation. Linear mixed model analysis revealed that MOR activation had a significant effect on inhibition of LPS-induced TLR4 activation. Furthermore, TLR4 had a significant effect to explain pain scores. Postoperative s les also displayed altered circulating matrix-degrading enzymes activity potential, but this was correlated neither to opioid administration nor to MOR activation potential. Conclusions: Our results show for the first time that (i) opioids administered to surgery patients result in modulation of ligand-induced TLR4 activation and (ii) postoperative pain is associated with increased circulating TLR4 activation potential. Our study further promotes the use of MOR activation potential rather than opioid intake in clinical studies measuring opioid exposure at a given time point. Clin Cancer Res 24(10) 2319–27. ©2018 AACR.
Publisher: American Association for Cancer Research (AACR)
Date: 03-04-2023
DOI: 10.1158/1541-7786.22526822.V1
Abstract: Clinicopathological features of prostate cancer patients in the study
Publisher: Springer Science and Business Media LLC
Date: 05-2020
Publisher: Portland Press Ltd.
Date: 26-11-2020
DOI: 10.1042/BCJ20200697
Abstract: Emerging advances in cancer therapy have transformed the landscape towards cancer immunotherapy regimens. Recent discoveries have resulted in the development of clinical immune checkpoint inhibitors that are ‘game-changers’ for cancer immunotherapy. Here we show that eEF2K, an atypical protein kinase that negatively modulates the elongation stage of protein synthesis, promotes the synthesis of PD-L1, an immune checkpoint protein which helps cancer cells to escape from immunosurveillance. Ablation of eEF2K in prostate and lung cancer cells markedly reduced the expression levels of the PD-L1 protein. We show that eEF2K promotes the association of PD-L1 mRNAs with translationally active polyribosomes and that translation of the PD-L1 mRNA is regulated by a uORF (upstream open reading-frame) within its 5′-UTR (5′-untranslated region) which starts with a non-canonical CUG as the initiation codon. This inhibitory effect is attenuated by eEF2K thereby allowing higher levels of translation of the PD-L1 coding region and enhanced expression of the PD-L1 protein. Moreover, eEF2K-depleted cancer cells are more vulnerable to immune attack by natural killer cells. Therefore, control of translation elongation can modulate the translation of this specific mRNA, one which contains an uORF that starts with CUG, and perhaps others that contain a similar feature. Taken together, our data reveal that eEF2K regulates PD-L1 expression at the level of the translation of its mRNA by virtue of a uORF in its 5′-region. This, and other roles of eEF2K in cancer cell biology (e.g. in cell survival and migration), may be exploited for the design of future therapeutic strategies.
Publisher: Springer Science and Business Media LLC
Date: 22-03-2019
DOI: 10.1038/S42004-019-0133-4
Abstract: The development of polyphenols as drugs for Alzheimer’s disease (AD) is thwarted by their meagre brain availability due to instability and poor druglikeness. Here we describe the successful development of stable, druglike polyphenolic analogues of the current AD drug rivastigmine, that have high apparent blood-brain barrier permeabilities and multifunctional properties for AD treatment. The compounds inhibit cholinesterases and amyloid beta (Aβ) fibrillation, protect against Aβ 42 -induced toxicity in vitro, and demonstrate efficacy in vivo in a transgenic Caenorhabditis elegans model expressing Aβ 42 , with potencies similar to rivastigmine and natural polyphenols. The results suggest that a tertiary amine substituent is amenable for developing water-soluble, membrane-permeable polyphenols, and its incorporation adjacent to a hydroxy group is favourable for intramolecular hydrogen bonding that facilitates membrane permeability. Carbamylation of one hydroxy group protects the polyphenols from degradation and mostly improves their membrane permeability. These design strategies may assist in the development of polyphenol-based drugs.
Publisher: American Association for Cancer Research (AACR)
Date: 03-04-2023
DOI: 10.1158/1541-7786.22512309.V1
Abstract: S1: Pretreatment of PC-3 and C4-2B cells with a FA Mix alters the response to palmitate lipotoxicity and serum-starvation. S2: Dose response assessment of palmitate supplementation on cell viability. S3: Pretreatment with the DGAT1 inhibitor AZD3988 does not affect PC-3 cell growth.
Start Date: 2019
End Date: 2020
Funder: Cure Cancer Australia Foundation
View Funded ActivityStart Date: 2018
End Date: 2019
Funder: Prostate Cancer Foundation of Australia
View Funded ActivityStart Date: 2018
End Date: 2021
Funder: National Health and Medical Research Council
View Funded Activity