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Cell Fate following Irradiation of MDA-MB-231 and MCF-7 Breast Cancer Cells Pre-Exposed to the Tetrahydroisoquinoline Sulfamate Microtubule Disruptor STX3451. Molecules 2022; 27:molecules27123819. [PMID: 35744942 PMCID: PMC9228122 DOI: 10.3390/molecules27123819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 05/26/2022] [Accepted: 05/30/2022] [Indexed: 11/16/2022] Open
Abstract
A tetrahydroisoquinoline (THIQ) core is able to mimic the A and B rings of 2-methoxyestradiol (2ME2), an endogenous estrogen metabolite that demonstrates promising anticancer properties primarily by disrupting microtubule dynamic instability parameters, but has very poor pharmaceutical properties that can be improved by sulfamoylation. The non-steroidal THIQ-based microtubule disruptor 2-(3-bromo-4,5-dimethoxybenzyl)-7-methoxy-6-sulfamoyloxy-1,2,3,4-tetrahydroisoquinoline (STX3451), with enhanced pharmacokinetic and pharmacodynamic profiles, was explored for the first time in radiation biology. We investigated whether 24 h pre-treatment with STX3451 could pre-sensitize MCF-7 and MDA-MB-231 breast cancer cells to radiation. This regimen showed a clear increase in cytotoxicity compared to the individual modalities, results that were contiguous in spectrophotometric analysis, flow cytometric quantification of apoptosis induction, clonogenic studies and microscopy techniques. Drug pre-treatment increased radiation-induced DNA damage, with statistically more double-strand (ds) DNA breaks demonstrated. The latter could be due to the induction of a radiation-sensitive metaphase block or the increased levels of reactive oxygen species, both evident after compound exposure. STX3451 pre-exposure may also delay DNA repair mechanisms, as the DNA damage response element ataxia telangiectasia mutated (ATM) was depressed. These in vitro findings may translate into in vivo models, with the ultimate aim of reducing both radiation and drug doses for maximal clinical effect with minimal adverse effects.
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2-Hydroxyestradiol Overcomes Mesenchymal Stem Cells-Mediated Platinum Chemoresistance in Ovarian Cancer Cells in an ERK-Independent Fashion. Molecules 2022; 27:molecules27030804. [PMID: 35164068 PMCID: PMC8839885 DOI: 10.3390/molecules27030804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 01/17/2022] [Accepted: 01/19/2022] [Indexed: 11/16/2022] Open
Abstract
Ovarian cancer (OC) is the second most common type of gynecological malignancy. Platinum (Pt)-based chemotherapy is the standard of care for OC, but toxicity and acquired chemoresistance has proven challenging. Recently, we reported that sensitivity to platinum was significantly reduced in a co-culture of OC cells with MSC. To discover compounds capable of restoring platinum sensitivity, we screened a number of candidates and monitored ability to induce PARP cleavage. Moreover, we monitored platinum uptake and expression of ABC transporters in OC cells. Our results showed that 2-hydroxyestradiol (2HE2), a metabolite of estradiol, and dasatinib, an Abl/Src kinase inhibitor, were significantly effective in overcoming MSC-mediated platinum drug resistance. Dasatinib activity was dependent on ERK1/2 activation, whereas 2HE2 was independent of the activation of ERK1/2. MSC-mediated platinum drug resistance was accompanied by reduced intracellular platinum concentrations in OC cells. Moreover, MSC co-cultured with OC cells resulted in downregulation of the expression of cellular transporters required for platinum uptake and efflux. Exposure to 2HE2 and other modulators resulted in an increase in intracellular platinum concentrations. Thus, 2HE2 and dasatinib might act as sensitizers to restore platinum drug sensitivity to OC cells and thus to limit TME-mediated chemoresistance in OC.
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Intracellular Signaling Responses Induced by Radiation within an In Vitro Bone Metastasis Model after Pre-Treatment with an Estrone Analogue. Cells 2021; 10:cells10082105. [PMID: 34440874 PMCID: PMC8394480 DOI: 10.3390/cells10082105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 08/03/2021] [Accepted: 08/03/2021] [Indexed: 12/27/2022] Open
Abstract
2-Ethyl-3-O-sulfamoyl-estra-1,3,5(10)16-tetraene (ESE-16) is an in silico-designed estradiol analogue which has improved the parent compound’s efficacy in anti-cancer studies. In this proof-of-concept study, the potential radiosensitizing effects of ESE-16 were investigated in an in vitro deconstructed bone metastasis model. Prostate (DU 145) and breast (MDA-MB-231) tumor cells, osteoblastic (MC3T3-E1) and osteoclastic (RAW 264.7) bone cells and human umbilical vein endothelial cells (HUVECs) were representative components of such a lesion. Cells were exposed to a low-dose ESE-16 for 24 hours prior to radiation at non-lethal doses to determine early signaling and molecular responses of this combination treatment. Tartrate-resistant acid phosphatase activity and actin ring formation were investigated in osteoclasts, while cell cycle progression, reactive oxygen species generation and angiogenic protein expression were investigated in HUVECs. Increased cytotoxicity was evident in tumor and endothelial cells while bone cells appeared to be spared. Increased mitotic indices were calculated, and evidence of increased deoxyribonucleic acid damage with retarded repair, together with reduced metastatic signaling was observed in tumor cells. RAW 264.7 macrophages retained their ability to differentiate into osteoclasts. Anti-angiogenic effects were observed in HUVECs, and expression of hypoxia-inducible factor 1-α was decreased. Through preferentially inducing tumor cell death and potentially inhibiting neovascularization whilst preserving bone physiology, this low-dose combination regimen warrants further investigation for its promising therapeutic application in bone metastases management, with the additional potential of limited treatment side effects.
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Elzayat MAM, Bayoumi AMA, Abdel-Bakky MS, Mansour AM, Kamel M, Abo-Saif A, Allam S, Salama A, Salama SA. Ameliorative effect of 2-methoxyestradiol on radiation-induced lung injury. Life Sci 2020; 255:117743. [PMID: 32371064 DOI: 10.1016/j.lfs.2020.117743] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 04/19/2020] [Accepted: 04/28/2020] [Indexed: 10/24/2022]
Abstract
AIMS Radiation-induced lung injury (RILI) is a serious complication of radiation therapy. Development of an effective drug that selectively protects normal lung tissues and sensitizes tumor cells to radiotherapy is an unmet need. 2-Methoxyestradiol (2ME2) possesses polypharmacological properties, which qualifies it as an effective radioprotector. Our aim is to explore the potential protective effects of 2ME2 against early and late stages of RILI and the underlying mechanisms. MAIN METHODS BALB/c mice were either treated with 2ME2 (50 mg/kg/day i.p., for 4 weeks); or received a single dose of 10 Gy ionizing radiation (IR) delivered to the lungs; or 10 Gy IR and 2ME2. Animal survival and pulmonary functions were evaluated. Immune-phenotyping of alveolar macrophages (AM) in the broncho-alveolar lavage fluids (BALF) was determined by flow cytometry. ELISA was used to evaluate the expression levels of TNF-α, TGF-β; and IL-10 in BALF. Lung tissues were used for histopathological examination or immunofluorescence staining for CD68 (pan-macrophage marker), Arginase-1 (Arg1, M2-specific marker), inducible nitric oxide synthase (iNOS, M1-specific marker) and HIF-1α. VEGF and γH2AX expression in lung tissues were detected by western blot. KEY FINDINGS The results demonstrated that 2ME2 improved the survival, lung functions and histopathological parameters of irradiated mice. Additionally, it attenuated the radiation-induced AM polarization and reduced the pneumonitis and fibrosis markers in lung tissues. Significant reduction of TNF-α and TGF-β with concomitant increase in IL-10 concentrations were observed. Moreover, the expression of HIF-1α, VEGF and γH2AX declined. SIGNIFICANCE 2ME2 is a promising radioprotectant with fewer anticipated side effects.
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Affiliation(s)
| | - Asmaa M A Bayoumi
- Department of Biochemistry, Faculty of Pharmacy, Minia University, El-minia, Egypt.
| | - Mohamed Sadek Abdel-Bakky
- Department of Pharmacology and Toxicology, Faculty of Pharmacy (Boys), Al-Azhar University, Cairo, Egypt; Department of Pharmacology and Toxicology, College of Pharmacy, Qassim University, Buraydah 51452, Saudi Arabia.
| | - Ahmed M Mansour
- Department of Pharmacology and Toxicology, Faculty of Pharmacy (Boys), Al-Azhar University, Cairo, Egypt.
| | - Marwa Kamel
- Department of Tumor Biology, National Cancer Institute, Cairo University, Cairo, Egypt.
| | - Ali Abo-Saif
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Nahda University, Beni-Suef, Egypt; Department of Pharmacology, Faculty of Medicine (Boys), Al-Azhar University, Cairo, Egypt.
| | - Shady Allam
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Kafrelsheikh University, Kafr El Sheikh, Egypt..
| | - Abeer Salama
- Department of Pharmacology, National Research Centre, Doki, Giza, Egypt.
| | - Salama A Salama
- Department of Pharmacology and Toxicology, Faculty of Pharmacy (Boys), Al-Azhar University, Cairo, Egypt.
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Exposure of Breast and Lung Cancer Cells to a Novel Estrone Analog Prior to Radiation Enhances Bcl-2-Mediated Cell Death. Int J Mol Sci 2018; 19:ijms19102887. [PMID: 30249026 PMCID: PMC6212960 DOI: 10.3390/ijms19102887] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 09/04/2018] [Accepted: 09/04/2018] [Indexed: 12/22/2022] Open
Abstract
Following exposure of cells to gamma-radiation, a cascade of intracellular consequences may be observed in a semitemporal manner. This includes deoxyribonucleic acid (DNA) damage and reactive oxygen species (ROS) accumulation initially, with consequent signaling for DNA repair and facilitative regulation of the cell cycle. Failure to rectify the damage or ROS levels leads to induction of senescence or apoptosis. 2-Ethyl-3-O-sulfamoyl-estra-1,3,5(10),15-tetraen-17-ol (ESE-15-ol), a 2-methoxyestradiole analog designed in silico for superior pharmacokinetics, was investigated for its potential to enhance apoptotic signaling and decrease the long-term survival of cells exposed to radiation. Sequential early intracellular effects within radiation-treated MCF-7 breast- and A549 lung cancer cells pre-exposed to low-dose ESE-15-ol were investigated using various flow cytometric protocols, spectrophotometry, and microscopy. Long-term cellular survival and proliferation was examined using clonogenic studies, which demonstrated a significant decrease in the presensitized cells. Combination-treated cells exhibited increased superoxide formation, and decreased Bcl-2 expression and -phosphorylation. Induction of apoptosis and elevation of the sub-G1 phase was evident in the pre-exposed MCF-7 cells, although only minimally in the A549 cells at 48-h. These results indicate that low-dose ESE-15-ol may increase tumor response to radiation. Future studies will investigate the effect of ESE-15-ol pre-exposure on radiation-induced DNA damage and repair mechanisms.
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Yang F, Song L, Wang H, Wang J, Xu Z, Xing N. Combination of Quercetin and 2-Methoxyestradiol Enhances Inhibition of Human Prostate Cancer LNCaP and PC-3 Cells Xenograft Tumor Growth. PLoS One 2015; 10:e0128277. [PMID: 26011145 PMCID: PMC4444352 DOI: 10.1371/journal.pone.0128277] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 04/23/2015] [Indexed: 12/20/2022] Open
Abstract
Quercetin and 2-Methoxyestradiol (2-ME) are promising anti-cancer substances. Our previous in vitro study showed that quercetin synergized with 2-Methoxyestradiol exhibiting increased antiproliferative and proapoptotic activity in both androgen-dependent LNCaP and androgen-independent PC-3 human prostate cancer cell lines. In the present study, we determined whether their combination could inhibit LNCaP and PC-3 xenograft tumor growth in vivo and explored the underlying mechanism. Human prostate cancer LNCaP and PC-3 cells were inoculated subcutaneously in male BALB/c nude mice. When xenograft tumors reached about 100 mm3, mice were randomly allocated to vehicle control, quercetin or 2-Methoxyestradiol singly treated and combination treatment groups. After therapeutic intervention for 4 weeks, combination treatment of quercetin and 2-ME i) significantly inhibited prostate cancer xenograft tumor growth by 46.8% for LNCaP and 51.3% for PC-3 as compared to vehicle control group, more effective than quercetin (28.4% for LNCaP, 24.8% for PC3) or 2-ME (32.1% for LNCaP, 28.9% for PC3) alone; ii) was well tolerated by BALB/c mice and no obvious toxic reactions were observed; iii) led to higher Bax/Bcl-2 ratio, cleaved caspase-3 protein expression and apoptosis rate; and iv) resulted in lower phosphorylated AKT (pAKT) protein level, vascular endothelial growth factor protein and mRNA expression, microvascular density and proliferation rate than single drug treatment. These effects were more remarkable compared to vehicle group. Therefore, combination of quercetin and 2-ME can serve as a novel clinical treatment regimen owning the potential of enhancing antitumor effect on prostate cancer in vivo and lessening the dose and side effects of either quercetin or 2-ME alone. These in vivo results will lay a further solid basis for subsequent researches on this novel therapeutic regimen in human prostate cancer.
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Affiliation(s)
- Feiya Yang
- Department of Urology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, P.R. China
| | - Liming Song
- Department of Urology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, P.R. China
| | - Huiping Wang
- Department of Reproductive Immunology and Pharmacology, National Research Institute for Family Planning, Beijing, P.R. China
| | - Jun Wang
- Department of Neurosurgery, the First hospital of China Medical University, Shenyang, P.R. China
| | - Zhiqing Xu
- Institute of Neuroscience, Beijing Key Laboratory of Neural Regeneration and Repair, Capital Medical University, Beijing, P.R. China
| | - Nianzeng Xing
- Department of Urology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, P.R. China
- * E-mail:
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Choi SH, Hong ZY, Nam JK, Lee HJ, Jang J, Yoo RJ, Lee YJ, Lee CY, Kim KH, Park S, Ji YH, Lee YS, Cho J, Lee YJ. A Hypoxia-Induced Vascular Endothelial-to-Mesenchymal Transition in Development of Radiation-Induced Pulmonary Fibrosis. Clin Cancer Res 2015; 21:3716-26. [DOI: 10.1158/1078-0432.ccr-14-3193] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 04/06/2015] [Indexed: 11/16/2022]
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Mallett CL, Lim H, Thind K, Chen Y, Ribot EJ, Martinez F, Scholl TJ, Foster PJ. Longitudinal anatomical and metabolic MRI characterization of orthotopic xenograft prostate tumors in nude mice. J Magn Reson Imaging 2013; 40:848-56. [PMID: 24924594 DOI: 10.1002/jmri.24433] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 09/01/2013] [Indexed: 01/04/2023] Open
Abstract
PURPOSE To assess anatomic and functional magnetic resonance imaging (MRI) for monitoring of tumor volume and metabolism of orthotopic xenograft prostate cancer tumors. MATERIALS AND METHODS Human-derived PC-3M cells were implanted into the prostate in 22 nude mice. Tumor volume and MRI appearance were monitored for up to 29 days. Histology was performed to detect metastases. Hyperpolarized [1-(13) C]pyruvate MRI was used to measure tumor metabolism on day 22. RESULTS Tumors were visible by MRI 9 days after tumor cell implantation. Tumor volume increased to 720 ± 190 mm(3) on day 29 of imaging. Metastasis was seen in the iliac lymph nodes at all timepoints, and in more distant lymph nodes at later timepoints, but was not detectable by MRI. Regions with low pyruvate uptake corresponded to regions with necrosis and had a higher lactate/pyruvate ratio (0.98 ± 0.4 vs. 1.6 ± 1.1). CONCLUSION MRI using the balanced steady-state free precession (bSSFP) sequence can be used to monitor tumor growth in orthotopic PC-3M tumors as early as 9 days post-injection. Hyperpolarized pyruvate MRI has potential to assess tumor metabolism and necrosis.
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Affiliation(s)
- Christiane L Mallett
- Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada; Department of Medical Biophysics, Western University, London, Ontario, Canada
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DaSilva JO, Amorino GP, Casarez EV, Pemberton B, Parsons SJ. Neuroendocrine-derived peptides promote prostate cancer cell survival through activation of IGF-1R signaling. Prostate 2013; 73. [PMID: 23192379 PMCID: PMC4085781 DOI: 10.1002/pros.22624] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
BACKGROUND Neuroendocrine (NE) cells promote the progression of prostate cancer to a castration-resistant state through the production of paracrine growth factors. We have demonstrated this principle using in vitro and in vivo proliferative endpoints; however, the contributions of NE-derived pro-survival factors and anti-apoptosis to this phenomenon have not been thoroughly investigated. METHODS Here, we utilized conditioned-medium (CM) from LNCaP cells, engineered to undergo NE differentiation, and examined its effects on PC3 and LNCaP cell survival. RESULTS Statistically significant changes in clonogenic survival, Annexin V staining, PARP cleavage and trypan blue positivity of approximately twofold were observed in the presence of NE-derived CM relative to control-CM for both LNCaP and PC3 cells. These changes were partially abrogated by antagonists of the neuropeptides neurotensin, bombesin, and PTHrP. Selective inhibitors of IGF-1R, EGFR or Src caused significant and nearly complete blockade of prostate cancer cell survival due to NE secretions. Similar increases in cell survival were observed for LNCaP or PC3 cells treated with NE-derived medium in the presence of docetaxel. Increased phosphorylation of IGF-1R, following treatment with NE-derived medium, was accompanied by decreased protein tyrosine phosphatase, receptor type F (PTPRF) mRNA, and protein levels. Overexpression of PTPRF decreased cell survival, the amplitude and duration of IGF-1R phosphorylation, and enhanced PARP cleavage in the presence of NE-derived medium. CONCLUSIONS These data support the hypothesis that NE-derived factors act upon prostate cancer cells to stimulate pro-survival signaling and describe a novel mechanism of cross-talk between NE-derived factors and IGF-1R, mediated in part by PTPRF.
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MESH Headings
- Blotting, Western
- Cell Line, Tumor
- Cell Survival/physiology
- ErbB Receptors/antagonists & inhibitors
- ErbB Receptors/metabolism
- Gene Expression Regulation, Enzymologic
- Gene Expression Regulation, Neoplastic
- Humans
- Male
- Neoplasms, Hormone-Dependent/enzymology
- Neoplasms, Hormone-Dependent/genetics
- Neoplasms, Hormone-Dependent/metabolism
- Neurosecretory Systems/metabolism
- Parathyroid Hormone-Related Protein/antagonists & inhibitors
- Parathyroid Hormone-Related Protein/metabolism
- Prostatic Neoplasms/enzymology
- Prostatic Neoplasms/genetics
- Prostatic Neoplasms/metabolism
- Prostatic Neoplasms/pathology
- RNA, Messenger/chemistry
- RNA, Messenger/genetics
- Real-Time Polymerase Chain Reaction
- Receptor, IGF Type 1/antagonists & inhibitors
- Receptor, IGF Type 1/metabolism
- Receptor-Like Protein Tyrosine Phosphatases, Class 2/genetics
- Receptor-Like Protein Tyrosine Phosphatases, Class 2/metabolism
- Signal Transduction
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Affiliation(s)
- John O. DaSilva
- Departments of Microbiology, Cancer Center, University of Virginia Health Sciences Center, Charlottesville, VA 22908
| | - George P. Amorino
- Radiation Oncology and Cancer Center, University of Virginia Health Sciences Center, Charlottesville, VA 22908
| | - Eli V. Casarez
- Departments of Microbiology, Cancer Center, University of Virginia Health Sciences Center, Charlottesville, VA 22908
| | - Bradley Pemberton
- Radiation Oncology and Cancer Center, University of Virginia Health Sciences Center, Charlottesville, VA 22908
| | - Sarah J. Parsons
- Departments of Microbiology, Cancer Center, University of Virginia Health Sciences Center, Charlottesville, VA 22908
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Dai XF, Ding J, Zhang RG, Ren JH, Ma CMC, Wu G. Radiosensitivity enhancement of human hepatocellular carcinoma cell line SMMC-7721 by sorafenib through the MEK/ERK signal pathway. Int J Radiat Biol 2013; 89:724-31. [DOI: 10.3109/09553002.2013.791405] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Sarkar S, Brautigan DL, Parsons SJ, Larner JM. Androgen receptor degradation by the E3 ligase CHIP modulates mitotic arrest in prostate cancer cells. Oncogene 2012; 33:26-33. [PMID: 23246967 DOI: 10.1038/onc.2012.561] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Revised: 09/14/2012] [Accepted: 10/09/2012] [Indexed: 02/06/2023]
Abstract
The androgen receptor (AR) has a vital role in the onset and progression of prostate cancer by promoting G1-S progression, possibly by functioning as a licensing factor for DNA replication. We here report that low dose 2-methoxyestradiol (2-ME), an endogenous estrogen metabolite, induces mitotic arrest in prostate cancer cells involving activation of the E3 ligase CHIP (C-terminus of Hsp70-interacting protein) and degradation of the AR. Depletion of the AR by small interfering RNA (siRNA) eliminates 2-ME-induced arrest and introducing AR into PC3-M cells confers 2-ME-induced mitotic arrest. Knockdown of CHIP or MDM2 (mouse homolog of double minute 2 protein) individually or in combination reduced AR degradation and abrogated M phase arrest induced by 2-ME. Our data link AR degradation via ubiquitination to mitotic arrest. Targeting the AR by activating E3 ligases such as CHIP represents a novel strategy for the treatment of prostate cancer.
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Affiliation(s)
- S Sarkar
- Department of Radiation Oncology, University of Virginia Health Sciences Center, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - D L Brautigan
- 1] Center for Cell Signaling, University of Virginia, Charlottesville, VA, USA [2] Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - S J Parsons
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - J M Larner
- Department of Radiation Oncology, University of Virginia Health Sciences Center, University of Virginia School of Medicine, Charlottesville, VA, USA
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The novel Akt inhibitor Palomid 529 (P529) enhances the effect of radiotherapy in prostate cancer. Br J Cancer 2009; 100:932-40. [PMID: 19240717 PMCID: PMC2661786 DOI: 10.1038/sj.bjc.6604938] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Radiotherapy (RT) is a common treatment for localised prostate cancer, but can cause important side effects. The therapeutic efficacy of RT can be enhanced by pharmacological compounds that target specific pathways involved in cell survival. This would elicit a similar therapeutic response using lower doses of RT and, in turn, reducing side effects. This study describes the antitumour activity of the novel Akt inhibitor 8-(1-Hydroxy-ethyl)-2-methoxy-3-(4-methoxy-benzyloxy)-benzo[c]chromen-6-one (Palomid 529 or P529) as well as its ability to decrease radiation-activated phospho-Akt (p-Akt) signalling in a prostate cancer model. P529 showed a potent antiproliferative activity in the NCI-60 cell lines panel, with growth inhibitory 50 (GI50) <35 μM. In addition, P529 significantly enhanced the antiproliferative effect of radiation in prostate cancer cells (PC-3). Analysis of signalling pathways targeted by P529 exhibited a decrease in p-Akt, VEGF, MMP-2, MMP-9, and Id-1 levels after radiation treatment. Moreover, the Bcl-2/Bax ratio was also reduced. Treatment of PC-3 tumour-bearing mice with 20 mg kg−1 P529 or 6 Gy radiation dose decreased tumour size by 42.9 and 53%, respectively. Combination of both treatments resulted in 77.4% tumour shrinkage. Decreased tumour growth was due to reduced proliferation and increased apoptosis (as assessed by PCNA and caspase-3 immunostaining). Our results show the antitumour efficacy of P529 alone, and as a radiosensitiser, and suggest that this compound could be used in the future to treat human prostate cancer.
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Singhal SS, Roth C, Leake K, Singhal J, Yadav S, Awasthi S. Regression of prostate cancer xenografts by RLIP76 depletion. Biochem Pharmacol 2008; 77:1074-83. [PMID: 19073149 DOI: 10.1016/j.bcp.2008.11.013] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2008] [Revised: 11/09/2008] [Accepted: 11/18/2008] [Indexed: 10/21/2022]
Abstract
RLIP76 plays a central role in radiation and chemotherapy resistance through its activity as a multi-specific ATP-dependent transporter which is over-expressed in a number of types of cancers. RLIP76 appears to be necessary for cancer cell survival because both in vitro cell culture and in vivo animal tumor studies show that depletion or inhibition of RLIP76 causes selective toxicity in malignant cells. RLIP76 induces apoptosis in cancer cells through the accumulation of endogenously formed GS-E. The results of our in vivo studies demonstrate that administration of RLIP76 antibodies, siRNA or anti-sense to mice bearing xenografts of PC-3 prostate cancer cells leads to near complete regression of established subcutaneous xenografts with no apparent toxic effects. Since anti-RLIP76 IgG (which inhibit RLIP76-mediated transport), siRNA and antisense (which deplete RLIP76) showed similar tumor regressing activities, our results indicate that the inhibition of RLIP76 transport activity at the cell surface is sufficient for observed anti-tumor activity. These studies indicate that RLIP76 serves a key effector function for the survival of prostate cancer cells and that it is a valid target for cancer therapy.
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Affiliation(s)
- Sharad S Singhal
- Department of Molecular Biology and Immunology, University of North Texas Health Science Center, Fort Worth, TX 76107, USA.
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Kato S, Sadarangani A, Lange S, Delpiano AM, Vargas M, Brañes J, Carvajal J, Lipkowitz S, Owen GI, Cuello MA. 2-methoxyestradiol mediates apoptosis through caspase-dependent and independent mechanisms in ovarian cancer cells but not in normal counterparts. Reprod Sci 2008; 15:878-894. [PMID: 19050321 PMCID: PMC9019574 DOI: 10.1177/1933719108324171] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2024]
Abstract
OBJECTIVE The estrogen metabolite 2-methoxyestradiol has shown antitumorigenic action in some epithelial tumors. In the present work we investigate its effects in ovarian cancer used alone or in combination with other apoptotic-inducing reagents such as tumor necrosis factor-related apoptosis-inducing ligand. METHODS To assess the effect of 2-methoxyestradiol, dose response and time courses in ovarian cancer and normal cells were conducted. Apoptosis was confirmed through DNA laddering, by flow cytometry, and Western blotting of proteins involved in the apoptotic cascade. RESULTS 2-Methoxyestradiol induced apoptosis in ovarian cancer cells but not in normal counterparts. 2-Methoxyestradiol activates both the intrinsic and extrinsic apoptotic pathways. 2-Methoxyestradiol-mediated apoptosis involves reactive oxygen species generation and caspase-dependent and caspase-independent mechanisms. We also demonstrate that 2-methoxyestradiol selectively induces an additive/synergistic apoptotic response in ovarian cancer cells when used in combination with tumor necrosis factor-related apoptosis-inducing ligand. CONCLUSIONS 2-Methoxyestradiol, alone or in combination with tumor necrosis factor-related apoptosis-inducing ligand, should be considered as a potential treatment for ovarian cancer.
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Affiliation(s)
- Sumie Kato
- Department of Obstetrics and Gynecology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
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