P13.14 Inhibition of extracellular carbonic anhydrases reduces glioblastoma cell invasion

2021 ◽  
Vol 23 (Supplement_2) ◽  
pp. ii35-ii35
Author(s):  
M Proescholdt ◽  
Z Qiu ◽  
J Falter ◽  
N Schmidt

Abstract BACKGROUND Malignant gliomas metabolize glucose preferably by glycolysis which is in accordance with the Warburg effect. This induces a high demand of glucose combined with a significant lactic acid load. The hypoxia-inducible carbonic anhydrase (CA) IX has been shown to moderate the extrusion of hydrogen ions into the extracellular space. Since the acidification of the extracellular environment contributes to host tissue invasion due to activation of proteolytic enzymes, we hypothesized that CA IX plays an important role in malignant glioma Recently, specific small molecule inhibitors of this enzyme have been developed and may provide an innovative strategy for anti - invasive treatment. MATERIAL AND METHODS Two established and 4 primary GBM cell lines (2 with mesenchymal and 2 with proneural transcriptional profile) were exposed to the CAIX inhibitor U104 under normoxic and hypoxic conditions. Cell toxicity was measured by ATP and crystal violet assay. For invasion assessment, a matrigel invasion chamber system with 8 µm pore size polycarbonate filter was used. CAIX expression was analyzed by quantitative RTPCR and Western Blot. RESULTS Hypoxia significantly induced CAIX expression in all cell lines. Invasiveness increased significantly under hypoxic conditions in the mesenchymal cells (p < 0.01). Regardless of oxygenation status, the mesenchymal group displayed significantly higher invasiveness compared to the proneural group (p = 0.006). Looking at all cell lines, invasion is significantly inhibited by U104, both under normoxic and hypoxic conditions (p < 0.01). However, while the mesenchymal group showed the highest susceptibility to CAIX inhibition followed by the proneurally differentiated group, the established cell lines were entirely refractory to CAIX inhibition. CONCLUSION Our data demonstrate that CAIX inhibition can effectively inhibit invasion in malignant glioma cells independent from oxygenation status, however the effects are significantly influenced by cell type specific biological features.

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi27-vi27
Author(s):  
Martin Proescholdt ◽  
Zhenwei Qiu ◽  
Johannes Falter ◽  
Anette Lohmeier ◽  
Nils-Ole Schmidt

Abstract BACKGROUND Malignant gliomas metabolize glucose preferably by glycolysis which is in accordance with the Warburg effect. This induces a high demand of glucose combined with a significant lactic acid load. The hypoxia-inducible carbonic anhydrase (CA) IX has been shown to moderate the extrusion of hydrogen ions into the extracellular space. Since the acidification of the extracellular environment contributes to host tissue invasion due to activation of proteolytic enzymes, we hypothesized that CA IX plays an important role in malignant glioma Recently, specific small molecule inhibitors of this enzyme have been developed and may provide an innovative strategy for anti – invasive treatment. METHODS Two established and 4 primary GBM cell lines (2 with mesenchymal and 2 with proneural transcriptional profile) were exposed to the CAIX inhibitor U104 under normoxic and hypoxic conditions. Cell toxicity was measured by ATP and crystal violet assay. For invasion assessment, a matrigel invasion chamber system with 8 µm pore size polycarbonate filter was used. CAIX expression was analyzed by quantitative RTPCR and Western Blot. RESULTS Hypoxia significantly induced CAIX expression in all cell lines. Invasiveness increased significantly under hypoxic conditions in the mesenchymal cells (p < 0.01). Regardless of oxygenation status, the mesenchymal group displayed significantly higher invasiveness compared to the proneural group (p = 0.006). Looking at all cell lines, invasion is significantly inhibited by U104, both under normoxic and hypoxic conditions (p < 0.01). However, while the mesenchymal group showed the highest susceptibility to CAIX inhibition followed by the proneurally differentiated group, the established cell lines were entirely refractory to CAIX inhibition. CONCLUSION Our data demonstrate that CAIX inhibition can effectively inhibit invasion in malignant glioma cells independent from oxygenation status, however the effects are significantly influenced by cell type specific biological features.


2020 ◽  
Vol 3 (Supplement_1) ◽  
pp. i9-i9
Author(s):  
Martin Proescholdt ◽  
Qiu Zhenwei ◽  
Lohmeier Annette ◽  
Schmidt Nils-Ole ◽  
Merrill Marsha

Abstract OBJECTIVE Malignant gliomas metabolize glucose preferably by glycolysis which is in accordance with the Warburg effect. This induces a high demand of glucose combined with a significant lactic acid load. The hypoxia-inducible carbonic anhydrase (CA) IX has been shown to moderate the extrusion of hydrogen ions into the extracellular space. Since the acidification of the extracellular environment contributes to host tissue invasion due to activation of proteolytic enzymes, we hypothesized that CA IX plays an important role in malignant glioma Recently, specific small molecule inhibitors of this enzyme have been developed and may provide an innovative strategy for anti – invasive treatment. METHODS Two established and 4 primary GBM cell lines (2 with mesenchymal and 2 with proneural transcriptional profile) were exposed to the CAIX inhibitor U104 under normoxic and hypoxic conditions. Cell toxicity was measured by ATP and crystal violet assay. For invasion assessment, a matrigel invasion chamber system with 8 µm pore size polycarbonate filter was used. CAIX expression was analyzed by quantitative RTPCR and Western Blot. RESULTS Hypoxia significantly induced CAIX expression in all cell lines. Invasiveness increased significantly under hypoxic conditions in the mesenchymal cells (p < 0.01). Regardless of oxygenation status, the mesenchymal group displayed significantly higher invasiveness compared to the proneural group (p = 0.006). Looking at all cell lines, invasion is significantly inhibited by U104, both under normoxic and hypoxic conditions (p < 0.01). However, while the mesenchymal group showed the highest susceptibility to CAIX inhibition followed by the proneurally differentiated group, the established cell lines were entirely refractory to CAIX inhibition. CONCLUSION Our data demonstrate that CAIX inhibition can effectively inhibit invasion in malignant glioma cells independent from oxygenation status, however the effects are significantly influenced by cell type specific biological features.


2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 3038-3038
Author(s):  
I. M. Zitron ◽  
O. Norkina ◽  
Z. Al-Kadhimi ◽  
G. R. Barger ◽  
L. G. Lum ◽  
...  

3038 Background: Malignant gliomas are the most common primary brain tumors in adults. The prognosis for patients with glioblastoma remains poor despite aggressive multimodality treatment including surgery and chemoradiotherapy. The receptor tyrosine kinases EGFR, mutant EGFR (EGFRvIII), and HER2/neu are expressed on the majority of glioblastomas and are potential targets for activated T cells (ATCs) armed with bispecific antibodies (BiAbs). Methods: ATCs were generated from human peripheral blood mononuclear cells (PBMC) by culture for 14 days with monoclonal anti-CD3 and interleukin-2 and armed with HER2Bi and/or EGFRBi. HER2Bi- and/or EGFRBi-armed ATCs were examined for in vitro cytotoxicity (MTT and 51Cr release assays) against long-term malignant glioma lines (U87MG, U118MG, and U251MG) as well as primary glioblastoma lines derived from surgical specimens. Expression of EGFR and HER2/neu were evaluated by FACS. Anti-CD133 coated magnetic microbeads were used to separate CD133-positive and CD133-negative cell populations. Results: EGFRBi-armed ATCs killed up to 85% of U87, U118, and U251 targets. HER2Bi-armed ATCs exhibited comparable cytotoxicity against U118 and U251, but did not kill HER2-negative glioma U87. Cytotoxicity exhibited by either HER2Bi- or EGFRBi-armed ATCs against four primary glioblastoma cell lines was 50–80%. We found that both CD133-negative and CD133-positive cell populations were susceptible to killing by armed ATCs. When we armed ATCs simultaneously with HER2Bi and EGFRBi, killing by doubly armed ATCs was equal to or greater than that by EGFRBi-armed ATCs against the tested cell lines. Conclusions: BiAbs efficiently target ATCs to kill EGFR and/or HER2/neu expressing glioblastomas. Long-term malignant glioma cell lines and primary lines derived from surgical specimens are equally susceptible. Both CD133-negative and CD133-positive (the putative glioma stem cells) are killed. ATCs armed with BiAbs represent a potentially valuable adjuvant to current treatment. No significant financial relationships to disclose.


2018 ◽  
Vol 51 (6) ◽  
pp. 2496-2508 ◽  
Author(s):  
Danfeng Zhang ◽  
Dawei Dai ◽  
Mengxia Zhou ◽  
Zhenxing Li ◽  
Chunhui Wang ◽  
...  

Background/Aims: Cyclin D1 (CCND1) is frequently overexpressed in malignant gliomas. We have previously shown ectopic overexpression of CCND1 in human malignant gliomas cell lines. Methods: Quantitative reverse transcriptase PCR (qRT-PCR) and Western Blot (WB) was performed to investigate the expression of CCND1 in glioma tissues and cell lines. The biological function of CCND1 was also investigated through knockdown and overexpression of BCYRN1 in vitro. Results: Here we reported that CCND1 expression was positively associated with the pathological grade and proliferative activity of astrocytomas, as the lowest expression was found in normal brain tissue (N = 3) whereas the highest expression was in high-grade glioma tissue (N = 25). Additionally, we found that the expression level of CCND1 was associated with IC50 values in malignant glioma cell lines. Forced inhibition of CCND1 increased temozolomide efficacy in U251 and SHG-44 cells. After CCND1 overexpression, the temozolomide efficacy decreased in U251 and SHG-44 cells. Colony survival assay and apoptosis analysis confirmed that CCND1 inhibition renders cells more sensitive to temozolomide treatment and temozolomide-induced apoptosis in U251 and SHG-44 cells. Inhibition of P-gp (MDR1) by Tariquidar overcomes the effects of CCND1 overexpression on inhibiting temozolomide-induced apoptosis. Inhibition of CCND1 inhibited cell growth in vitro and in vivo significantly more effectively after temozolomide treatments than single temozolomide treatments. Finally, inhibition of CCND1 in glioma cells reduced tumor volume in a murine model. Conclusion: Taken together, these data indicate that CCND1 overexpression upregulate P-gp and induces chemoresistance in human malignant gliomas cells and that inhibition of CCND1 may be an effective means of overcoming CCND1 associated chemoresistance in human malignant glioma cells.


2013 ◽  
Vol 119 (6) ◽  
pp. 1415-1423 ◽  
Author(s):  
Daniela A. Bota ◽  
Daniela Alexandru ◽  
Stephen T. Keir ◽  
Darell Bigner ◽  
James Vredenburgh ◽  
...  

Object Recurrent malignant gliomas have inherent resistance to traditional chemotherapy. Novel therapies target specific molecular mechanisms involved in abnormal signaling and resistance to apoptosis. The proteasome is a key regulator of multiple cellular functions, and its inhibition in malignant astrocytic lines causes cell growth arrest and apoptotic cell death. The proteasome inhibitor bortezomib was reported to have very good in vitro activity against malignant glioma cell lines, with modest activity in animal models as well as in clinical trials as a single agent. In this paper, the authors describe the multiple effects of bortezomib in both in vitro and in vivo glioma models and offer a novel explanation for its seeming lack of activity. Methods Glioma stem-like cells (GSCs) were obtained from resected glioblastomas (GBMs) at surgery and expanded in culture. Stable glioma cell lines (U21 and D54) as well as temozolomide (TMZ)-resistant glioma cells derived from U251 and D54-MG were also cultured. GSCs from 2 different tumors, as well as D54 and U251 cells, were treated with bortezomib, and the effect of the drug was measured using an XTT cell viability assay. The activity of bortezomib was then determined in D54-MG and/or U251 cells using apoptosis analysis as well as caspase-3 activity and proteasome activity measurements. Human glioma xenograft models were created in nude mice by subcutaneous injection. Bevacizumab was administered via intraperitoneal injection at a dose of 5 mg/kg daily. Bortezomib was administered by intraperitoneal injection 1 hour after bevacizumab administration in doses of at a dose of 0.35 mg/kg on days 1, 4, 8, and 11 every 21 days. Tumors were measured twice weekly. Results Bortezomib induced caspase-3 activation and apoptotic cell death in stable glioma cell lines and in glioma stem-like cells (GSCs) derived from malignant tumor specimens Furthermore, TMZ-resistant glioma cell lines retained susceptibility to the proteasome inhibition. The bortezomib activity was directly proportional with the cells' baseline proteasome activity. The proteasome inhibition stimulated both hypoxia-inducible factor (HIF)–1α and vascular endothelial growth factor (VEGF) production in malignant GSCs. As such, the VEGF produced by GSCs stimulated endothelial cell growth, an effect that could be prevented by the addition of bevacizumab (VEGF antibody) to the media. Similarly, administration of bortezomib and bevacizumab to athymic mice carrying subcutaneous malignant glioma xenografts resulted in greater tumor inhibition and greater improvement in survival than administration of either drug alone. These data indicate that simultaneous proteasome inhibition and VEGF blockade offer increased benefit as a strategy for malignant glioma therapy. Conclusions The results of this study indicate that combination therapies based on bortezomib and bevacizumab might offer an increased benefit when the two agents are used in combination. These drugs have a complementary mechanism of action and therefore can be used together to treat TMZ-resistant malignant gliomas.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Beyza Ecem Öz Bedir ◽  
Emine Terzi ◽  
Ender Şimşek ◽  
İbrahim Karakuş ◽  
Tuğba Kevser Uysal ◽  
...  

Abstract Objectives To determine the effects of hypoxia-inducible factors (HIF)-1 inhibitors on carbonic anhydrase-IX (CA-IX) enzyme and vascular endothelial growth factor (VEGF) in melanoma. The HIF-1 pathway induces tumor growth and metastasis by stimulating the expression of CA-IX enzyme and VEGF proteins. Methods We evaluated the inhibition effects of Acriflavine and Echinomycin on CA-IX enzyme and VEGF in WM115 (primary) and SKMEL30 (metastatic) cell lines in normoxic and hypoxic conditions with Enzyme Linked Immunosorbent Assay. The cytotoxic activity of HIF-1 inhibitors was performed by using WST-1 assay. All experiments were performed at 450 nm using Epoch™ Microplate Spectrophotometer. Results IC50 values were observed with a concentration of 3 μmol/L for Echinomycin and Acriflavine in the WST-1 assay. Decreased CA-IX and VEGF levels were determined in both normoxia and hypoxia after inhibitors’ treatment with WM115 and SKMEL30 cell lines (p<0.05). Inhibitory effect of HIF-1 inhibitors on CA-IX and VEGF proteins was observed in cell lines WM115 and SKMEL30. Conclusions Due to the importance of our study, using HIF-1 inhibitors may be an alternative treatment for melanoma. Also to design new HIF-1 inhibitor derivatives is a promising approach for further studies targeting CA-IX enzyme and VEGF.


2007 ◽  
Vol 106 (4) ◽  
pp. 646-651 ◽  
Author(s):  
Mahmud Uzzaman ◽  
Gordon Keller ◽  
Isabelle M. Germano

Object Death receptor targeting is an attractive approach in experimental treatment for tumors such as malignant gliomas, which are resistant to radiation and chemotherapy. Among the family of cytokines referred to as death li gands, tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) has attracted clinical interest. The aim of this study was to assess whether TRAIL can be used as an adjuvant to temozolomide (TMZ) for apoptosis induction in malignant glioma cell lines. Methods Six human malignant glioma cell lines (A172, U87, U251, T98, U343, and U373) were exposed to human (h)TRAIL, TMZ, or an hTRAIL/TMZ combined treatment. Cell viability was assayed using 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide and phase-contrast microscopy. Cell apoptosis was detected using the terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick-end labeling technique and quantified using flow cytometric analysis. The apoptosis signaling cascade was studied with Western blotting. The additive effects of hTRAIL and TMZ resulted in a significant decrease in cell viability and an increased apoptotic rate. Expression of the death receptors DR5 and DR4 in two cell lines (A172 and U251) upregulated significantly when they were used in combination hTRAIL/TMZ treatment (p < 0.05 compared with baseline control), leading to activation of caspase-8 and caspase-3 (p < 0.05 compared with baseline control) and confirming an extrinsic apoptotic pathway. A cell intrinsic pathway through mitochondrial cytochrome c was not activated. Conclusions Based on this work, one may infer that hTRAIL should be considered as an adjuvant treatment for TMZ-resistant human malignant gliomas.


2006 ◽  
Vol 81 (1) ◽  
pp. 27-38 ◽  
Author(s):  
Harun M. Said ◽  
Adrian Staab ◽  
Carsten Hagemann ◽  
Giles H. Vince ◽  
Astrid Katzer ◽  
...  

2007 ◽  
Vol 106 (4) ◽  
pp. 652-659 ◽  
Author(s):  
Henry M. Smilowitz ◽  
Jakob Weissenberger ◽  
Joachim Weis ◽  
Judith D. Brown ◽  
Rachel J. O'Neill ◽  
...  

Object The aim of this study was to develop and characterize a new orthotopic, syngeneic, transplantable mouse brain tumor model by using the cell lines Tu-9648 and Tu-2449, which were previously isolated from tumors that arose spontaneously in glial fibrillary acidic protein (GFAP)-v-src transgenic mice. Methods Striatal implantation of a 1-μl suspension of 5000 to 10,000 cells from either clone into syngeneic B6C3F1 mice resulted in tumors that were histologically identified as malignant gliomas. Prior subcutaneous inoculations with irradiated autologous cells inhibited the otherwise robust development of a microscopically infiltrating malignant glioma. Untreated mice with implanted tumor cells were killed 12 days later, when the resultant gliomas were several millimeters in diameter. Immunohistochemically, the gliomas displayed both the astroglial marker GFAP and the oncogenic form of signal transducer and activator of transcription–3 (Stat3). This form is called tyrosine-705 phosphorylated Stat3, and is found in many malignant entities, including human gliomas. Phosphorylated Stat3 was particularly prominent, not only in the nucleus but also in the plasma membrane of peripherally infiltrating glioma cells, reflecting persistent overactivation of the Janus kinase/Stat3 signal transduction pathway. The Tu-2449 cells exhibited three non-random structural chromosomal aberrations, including a deletion of the long arm of chromosome 2 and an apparently balanced translocation between chromosomes 1 and 3. The GFAP-v-src transgene was mapped to the pericentromeric region of chromosome 18. Conclusions The high rate of engraftment, the similarity to the high-grade malignant glioma of origin, and the rapid, locally invasive growth of these tumors should make this murine model useful in testing novel therapies for human malignant gliomas.


2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Chung Heon Ryu ◽  
Wan Soo Yoon ◽  
Kwang Ywel Park ◽  
Seong Muk Kim ◽  
Jung Yeon Lim ◽  
...  

Temozolomide (TMZ) has become a key therapeutic agent in patients with malignant gliomas; however, its survival benefit remains unsatisfactory. Valproic acid (VPA) has emerged as an anticancer drug via inhibition of histone deacetylases (HDACs), but the therapeutic advantages of a combination with VPA and TMZ remain poorly understood. The main aim of the present study was to determine whether an antitumor effect could be potentiated by a combination of VPA and TMZ, especially in TMZ-resistant cell lines. A combination of VPA and TMZ had a significantly enhanced antitumor effect in TMZ-resistant malignant glioma cells (T98 and U138). This enhanced antitumor effect correlated with VPA-mediated reduced O6-methylguanine-DNA methyltransferase (MGMT) expression, which plays an important role in cellular resistance to alkylating agents.In vitro, the combination of these drugs enhanced the apoptotic and autophagic cell death, as well as suppressed the migratory activities in TMZ-resistant cell lines. Furthermore,in vivoefficacy experiment showed that treatment of combination of VPA and TMZ significantly inhibited tumor growth compared with the monotherapy groups of mice. These results suggest that the clinical efficacy of TMZ chemotherapy in TMZ-resistant malignant glioma may be improved by combination with VPA.


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