Antitumor effect of 2-methoxyestradiol in a rat orthotopic brain tumor model (original) (raw)
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Archives italiennes de biologie, 2010
2-Methoxyestradiol (2ME), a metabolite deriving from 17-beta estradiol, is a well-established antiangiogenic, apoptotic and antiproliferative agent in cell cultures and animal models. 2ME may also exert its cytotoxic activity by interacting with tubulin and by causing an impairment of the microtubular system. The aim of this study was to investigate the relative effectiveness of 2ME on mouse neuroblastoma (C1300) and rat glioma (C6) cell lines in inducing morpho-functional changes and alteration of the microtubular system physiology. Cells, cultured in a medium supplemented with increasing 2ME micromolar concentrations, were submitted to morphological investigations, MTT assay and western blot analysis. 2ME-exposed cell lines displayed in comparison with control cells, morpho-functional changes such as reduction in cell number, a globular/shrunken shape, retraction or absence of cytoplasmic processes, inhibition of cell growth and cell decreased viability. Interestingly, all changes...
Journal of Neuro-Oncology, 2005
The purpose of this study was to investigate the potential effects of 2-methoxyestradiol, a natural mammalian steroid, in glioma cells, since antiproliferative effects of this compound had been shown earlier in several leukemia and carcinoma cell lines. The effects of 0.2, 2 and 20 lM concentrations of 2-methoxyestradiol were measured in three malignant human glioma cell lines (U87MG, U138MG, LN405) and one malignant rat glioma cell line (RG-2) using a microtiter-tetrazolium (MTT) assay. In all cell lines, a significant reduction of the viable cell number by more then 75% occurred (P < 0.05) for concentrations of 2 and 20 lM 2-methoxyestradiol after 6 days. A concentration of 0.2 lM had smaller effects (10-40% cell reduction), which were significant in two of the cell lines tested. The apoptotic nature of cell death was further analyzed in U87MG and RG-2 cells. Caspase-3 activity was significantly induced to levels between 3.4-and 23-fold after 4 days for the two higher 2-methoxyestradiol concentrations (P < 0.05). In the cell line RG-2 nuclear fragmentation was visible in many nuclei, following stains with Hoechst H33258. A round cell morphology occurred in most treated cells, which was not accompanied by a complete destruction of the microtubule network, as it can be observed with other microtubule targeting drugs. * These authors contributed equally to the work.
Oncology Reports, 2015
Hypoxic tumor cells are known to be more resistant to conventional chemotherapy and radiation than normoxic cells. However, the effects of 2-methoxyestradiol (2-ME), an anti-angiogenic, antiproliferative and pro-apoptotic drug, on hypoxic lung cancer cells are unknown. The aim of the present study was to compare the effects of 2-ME on cell growth, apoptosis, hypoxia-inducible factor 1α (HIF-1α) and HIF-2α gene and protein expression in A549 cells under normoxic and hypoxic conditions. To establish the optimal 2-ME concentration with which to carry out the apoptosis assay and to examine mRNA and protein expression of HIFs, cell growth analysis was carried out through N-hexa-methylpararosaniline staining assays in A549 cell cultures treated with one of five different 2-ME concentrations at different times under normoxic or hypoxic growth conditions. The 2-ME concentration of 10 mM at 72 h was selected to perform all further experiments. Apoptotic cells were analyzed by flow cytometry. Western blotting was used to determine HIF-1α and HIF-2α protein expression in total cell extracts. Cellular localization of HIF-1α and HIF-2α was assessed by immunocytochemistry. HIF-1α and HIF-2α gene expression was determined by real-time PCR. A significant increase in the percentage of apoptosis was observed when cells were treated with 2-ME under a normoxic but not under hypoxic conditions (p=0.006). HIF-1α and HIF-2α protein expression levels were significantly decreased in cells cultured under hypoxic conditions and treated with 2-ME (p<0.001). Furthermore, 2-ME decreased the HIF-1α and HIF-2α nuclear staining in cells cultured under hypoxia. The HIF-1α and HIF-2α mRNA levels were significantly lower when cells were exposed to 2-ME under normoxia and hypoxia. Our results suggest that 2-ME could have beneficial results when used with conventional chemotherapy in an attempt to lower the invasive and metastatic processes during cancer development due to its effects on the gene expression and protein synthesis of HIFs.
International journal of oncology, 2013
Accurate imaging to identify hypoxic regions in tumors is key for radiotherapy planning. [F-18]‑fluoro-misonidazole ([F-18]-FMISO) is widely used for tumor hypoxia imaging and has the potential to optimize radiotherapy planning. However, the biological characteristics of intratumoral [F-18]-FMISO distribution have not yet been fully investigated. In hypoxic cells, the hypoxia-inducible factor-1 (HIF-1) target proteins that induce cellular proliferation and glucose metabolism, glucose transporter-1 (Glut-1) and hexokinase-II (HK-II), are upregulated. In this study, we determined the intratumoral distribution of [F-18]-FMISO by autoradiography (ARG) and compared it with pimonidazole uptake, expression of Glut-1, tumor proliferative activity (Ki-67 index) and glucose metabolism ([C-14]2-fluoro-2-deoxy-D-glucose uptake; [C-14]-FDG) in a glioma rat model. Five C6 glioma‑bearing rats were injected with [F-18]-FMISO and [C-14]-FDG. After 90 min, the rats were injected with pimonidazole and...
Purpose: Hypoxia-inducible factor 1α (HIF-1α) activity is one of the major players in hypoxia-mediated glioma progression and resistance to therapies, and therefore the focus of this study was the evaluation of HIF-1α modulation in relation to tumour response with the purpose of identifying imaging biomarkers able to document tumour response to treatment in a murine glioma model. Methods: U251-HRE-mCherry cells expressing Luciferase under the control of a hypoxia responsive element (HRE) andmCherry under the control of a constitutive promoter were used to assess HIF-1α activity and cell survival after treatment, both in vitro and in vivo, by optical, MRI and positron emission tomography imaging. Results: This cell model can be used to monitor HIF-1α activity after treatment with different drugs modulating transduction pathways involved in its regulation. After temozolomide (TMZ) treatment, HIF-1α activity is early reduced, preceding cell cytotoxicity. Optical imaging allowed monitoring of this process in vivo, and carbonic anhydrase IX (CAIX) expression was identified as a translatable non-invasive biomarker with potential clinical significance. A preliminary in vitro evaluation showed that reduction of HIF-1α activity after TMZ treatment was comparable to the effect of an Hsp90 inhibitor, opening the way for further elucidation of its mechanism of action. Conclusion: The results of this study suggest that the U251- HRE-mCherry cell model can be used for the monitoring of HIF-1α activity through luciferase and CAIX expression. These cells can become a useful tool for the assessment and improvement of new targeted tracers for potential theranostic procedures.
Clinical Cancer Research, 2004
Purpose: Head and neck squamous cell carcinomas have been reported to overexpress hypoxia-inducible factor (HIF)-1␣, a transcription factor that promotes expression of angiogenesis factors and resistance to programmed and therapy-induced cell death. 2-Methoxyestradiol (2ME2) is a natural compound with HIF-1␣ inhibitory activity that is currently being evaluated in phase 1 and 2 clinical trials for advanced solid tumors and multiple myeloma. To our knowledge, this is the first study to evaluate the effects of 2ME2 in head and neck squamous cell carcinoma. Experimental Design: In the present study, we investigated the effects of 2ME2 alone and in combination with paclitaxel, an active agent in recurrent or advanced head and neck squamous cell carcinoma. Results: 2ME2 exhibited antiproliferative and cytotoxic effects in a panel of five head and neck squamous cell carcinoma cell lines in the 0.5 to 10 mol/L range, including induction of G 2-M blockade, caspase-3/7 activation, and apoptosis at 48 hours. 2ME2 resulted in decreased nuclear HIF-1␣-binding activity and affected the expression of downstream genes, such as bid, a proapoptotic bcl-2 family member, and vascular endothelial growth factor, a proangiogenic cytokine. The up-regulation of Bid (57.5% at 12 hours, P < 0.0006) and inhibition of vascular endothelial growth factor secretion (57.7% at 24 hours, P < 0.015; and 50.3% at 48 hours, P < 0.0006) could be partially attributed to the effects on HIF-1␣, because HIF-1␣ small interfering RNAs produced similar effects. Finally, in vivo, in a xenograft model of head and neck squamous cell carcinoma using UM-SCC-11A cells, 2ME2 exhibited antitumor and antiangiogenic activity, as measured by CD31 immunostaining. Conclusions: These results provide support for the use of 2ME2 in combination with paclitaxel for the treatment of recurrent or advanced head and neck squamous cell carcinoma.
Cancer biology & therapy, 2006
To determine the maximum-tolerated dose (MTD) and toxicity profile of the novel anticancer agent, 2-methoxyestradiol (2ME2) administered orally, in patients with solid tumors. Twenty patients with refractory solid tumors were enrolled. 2ME2 was given orally starting at 400 mg bid with dose escalation until 3000 mg bid. Tumor biopsies were taken before and after starting the drug to assess for microvessel density by CD 31 and cell proliferation by Ki67 immunohistochemistry. Serial plasma samples collected up to 50 hours after first single oral dose for characterization of pharmacokinetics, were analyzed using liquid chromatography tandem mass-spectrometry. Eleven men and nine women received 2ME2 at dose levels of 400 mg bid (n = 3), 800 mg bid (n = 3), 1600 mg bid (n = 6), 2200 mg bid (n = 5) and 3000 mg bid (n = 3). There were no dose limiting toxicities, therefore the MTD was not defined. There was one episode of grade 4 angioedema in the 1600 mg bid dose level 38 days into 2ME2 tr...
2-Methoxyestradiol Damages DNA in Glioblastoma Cells by Regulating nNOS and Heat Shock Proteins
Antioxidants
Gliomas are the most prevalent primary tumors of the central nervous system (CNS), accounting for over fifty percent of all primary intracranial neoplasms. Glioblastoma (GBM) is the most prevalent form of malignant glioma and is often incurable. The main distinguishing trait of GBM is the presence of hypoxic regions accompanied by enhanced angiogenesis. 2-Methoxyestradiol (2-ME) is a well-established antiangiogenic and antiproliferative drug. In current clinical studies, 2-ME, known as Panzem, was examined for breast, ovarian, prostate, and multiple myeloma. The SW1088 grade III glioma cell line was treated with pharmacological and physiological doses of 2-ME. The induction of apoptosis and necrosis, oxidative stress, cell cycle arrest, and mitochondrial membrane potential were established by flow cytometry. Confocal microscopy was used to detect DNA damage. The Western blot technique determined the level of nitric oxide synthase and heat shock proteins. Here, for the first time, 2-...