• Journal of Radiopharmaceuticals and Molecular Probes
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• v.5 no.2
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• pp.101-112
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• 2019

Herein, 2-nitroimidazole-fluorophore conjugates were synthesized by linking 2-nitroimidazole and FITC or RITC via thiourea bonds. The prepared derivatives were stable for 2 h in Dulbecco's modified Eagle's medium (DMEM) at 37 ℃. The novel conjugates were studied for their in vitro uptake under hypoxic conditions using U87MG and CT-26 cell lines, showing significantly higher uptakes in hypoxic than normoxic cells. Immunohistochemical analysis confirmed hypoxia in U87MG and CT-26 xenografted tumor tissues. Moreover, the prepared conjugates were evaluated by in vivo experiments after intravenous injection in U87MG and CT-26 xenografted mice. Hypoxia was confirmed by immunohistochemistry of the prepared derivatives with co-injected pimonidazole. Confocal microscopy of the prepared derivatives showed strong fluorescence in hypoxic tumor tissues correlated with the pimonidazole distribution. This suggested that the 2-nitroimidazole-fluorophore conjugates are promising optical imaging probes for tumor hypoxia and are promising substitutes for pimonidazole immunohistochemistry, which requires a multi-step procedure of incubation involving antibody, second antibody, dye, hydrogen peroxide, and multiple washing steps.

• Molecules and Cells
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• v.40 no.7
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• pp.515-522
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• 2017

CD133, a pentaspan transmembrane glycoprotein, is generally used as a cancer stem cell marker in various human malignancies, but its biological function in cancer cells, especially in glioma cells, is largely unknown. Here, we demonstrated that forced expression of CD133 increases the expression of IL-$1{\beta}$ and its downstream chemokines, namely, CCL3, CXCL3 and CXCL5, in U87MG glioma cells. Although there were no apparent changes in cell growth and sphere formation in vitro and tumor growth in vivo, in vitro trans-well studies and in vivo tumor xenograft assays showed that neutrophil recruitment was markedly increased by the ectopic expression of CD133. In addition, the clinical relevance between CD133 expression and IL-$1{\beta}$ gene signature was established in patients with malignant gliomas. Thus, these results imply that glioma cells expressing CD133 are capable of modulating tumor microenvironment through the IL-$1{\beta}$ signaling pathway.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.19
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• pp.8225-8228
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• 2014

Glioma is one of the most common tumors in China and chemotherapy is critical for its treatment. Recent studies showed that benzyl isothiocyanate (BITC) could inhibit the growth of glioma cells, but the mechanisms are not fully understood. This study explored the inhibitory effect of BITC on invasion and angiogenesis of U87MG human glioma cells in vitro and in vivo, as well as potential mechanisms. It was found that BITC could inhibit invasion and angiogenesis of human glioma U87MG cells by inducing cell cycle arrest at phase G2/M. It also was demonstrated that BITC decreased expression of cyclin B1, p21, MMP-2/9, VE-cadherin, CD44, CXCR4 and MTH1, the activity of the telomerase and $PKC{\zeta}$ pathway. Microarray analysis was thus useful to explore the potential target genes related to tumorigenic processes. BITC may play important roles in the inhibition of invasion and angiogenesis of human glioma cells.

• Journal of Korean Neurosurgical Society
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• v.64 no.6
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• pp.864-872
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• 2021

Objective : The aim of our study is to investigate the cytotoxic, antioxidant, and antimicrobial effects of newly synthesized boron compounds in U87MG glioblastoma cell treatment. Methods : We synthesized boron glycine monoester (BGM) and boron glycine diester (BGD) structures containing boron atoms and determined their cytotoxic activities on glioblastoma by the MTT method. The inhibitory concentration 50 (IC₅₀) value was calculated with GraphPad Prism 5.0 program. The IC₅₀ values were administered 48 hours on U87MG glioblastoma cell. Catalase (CAT), acid phosphatase (ACP) and alkaline phosphatase (ALP) enzyme activity, malondialdehyde (MDA), total glutathione (GSH), and total protein levels were detected using spectrophotometric methods. We determined the antimicrobial activities of BGM and BGD with the disc diffusion method. Results : After 48 hours of BGM and BGD application to U87MG glioblastoma cells, we found the IC₅₀ value as 6.6 mM and 26 mM, respectively. CAT and ACP enzyme activities were decreased in BGM and BGD groups. MDA which is a metabolite of lipid peroxidation was increased in both boron compounds groups. GSH level was reduced especially in BGD group. BGM and BGD have been found to be antimicrobial effects. Conclusion : Boron compounds, especially the BGM, can provide a new therapeutic approach for the treatment of glioblastoma with their anticancer, antioxidant, and antimicrobial effects.

• Journal of Life Science
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• v.31 no.3
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• pp.266-279
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• 2021

The present study examined the cytotoxic effects of a Smilax china L. extract (SCLE) in human cancer (A-549, MCF-7, MDA-MB-231, U87-MG, AGS, MKN-74, and SNU-601) and normal MRC-5 fibroblasts, as well as in mesenchymal stem cells derived from dental tissue (DSC). The 50% inhibitory concentration (IC50) values for SCLE were significantly (p<0.05) lower in the cancer cell lines (A-549, MCF-7, MDA-MB-231, U87-MG, AGS, MKN-74 and SNU-601) than in the MRC-5 and DSC cells. Cell growth was significantly (p<0.05) more inhibited in the cancer cell lines treated with 200 ㎍/ml SCLE than in the normal MRC-5 and DSC, and anoikis-like floating cell morphology was observed in the SCLE-treated cancer cells. The cells detached by SCLE treatment were retrieved daily and assayed for viability and telomerase activity. Cells retrieved at 4 days showed significantly decreased viability and telomerase activity (p<0.05), as well as apoptosis-like abnormal morphology, when compared to cells retrieved in the previous 3 days. The ratio of apoptosis and cells in the G1 phase was significantly (p<0.05) increased in the A-549, AGS, and MCF-7 cancer cells treated with SCLE for 4 days compared to untreated controls. However, after SCLE treatment, cell adhesion was not increased by application of an inhibitor of the associated protein kinase (ROCK) that mainly contributes to the increase in cell attachment. This suggests that the cellular detachment by SCLE is probably controlled by a Rho-independent mechanism(s). These observations indicate that SCLE readily induces anoikis in cancer cells and could serve as a potent agent for cancer chemotherapy.

• Journal of Korean Neurosurgical Society
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• v.64 no.5
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• pp.716-725
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• 2021

Objective : The anti-tumor effect of the beta-adrenergic receptor antagonist propranolol in breast cancer is well known; however, its activity in glioblastoma is not well-evaluated. The Notch-Hes pathway is known to regulate cell differentiation, proliferation, and apoptosis. We investigated the effect of propranolol to human glioblastoma cell lines, and the role of Notch and Hes signaling in this process. Methods : We performed immunohistochemical staining on 31 surgically resected primary human glioblastoma tissues. We also used glioblastoma cell lines of U87-MG, LN229, and neuroblastoma cell line of SH-SY5Y in this study. The effect of propranolol and isoproterenol on cell proliferation was evaluated using the MTT assay (absorbance 570 nm). The impact of propranolol on gene expression (Notch and Hes) was evaluated using real-time polymerase chain reaction (RT-PCR, whereas protein levels of Notch1 and Hes1 were measured using Western blotting (WB), simultaneously. Small interfering RNA (siRNA) was used to suppress the Notch gene to investigate its role in the proliferation of glioblastoma. Results : Propranolol and isoproterenol caused a dose-dependent decrease in cell proliferation (MTT assay). RT-PCR showed an increase in Notch1 and Hes1 expression by propranolol, whereas WB demonstrated increase in Notch1 protein, but a decrease in Hes1 by propranolol. The proliferation of U87-MG and LN229 was not significantly suppressed after transfection with Notch siRNA. Conclusion : These results demonstrated that propranolol suppressed the proliferation of glioblastoma cell lines and neuroblastoma cell line, and Hes1 was more closely involved than Notch1 was in glioblastoma proliferation.

• Journal of Life Science
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• v.28 no.10
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• pp.1201-1211
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• 2018

The study compared the anti-aging, anti-adipogenesis, and anti-tumor effects of epigallocatechin-3- gallate (EGCG) in various cancer cell lines (SNU-601, MKN74, AGS, MCF-7, U87-MG, and A-549) and normal cell lines (MRC-5 fibroblasts, dental tissue-derived mesenchymal stem cells [DSC], and 3T3-L1 pro-adipocytes). Half inhibitory concentration ($IC_{50}$) values were significantly (p<0.05) higher in normal cell lines (~50 uM), when compared to that in cancer cell lines (~10 uM). For anti-aging effects, MRC-5 and DSC were exposed to 10 uM EGCG for up to five passages that did not display any growth arrest. Population doubling time and senescence-related ${\beta}-galactosidase$ ($SA-{\beta}-gal$) activity in treated cells were similar to untreated cells. For anti-adipogenic effects, mouse 3T3-L1 pre-adipocytes were induced to adipocytes in an adipogenic differentiation medium containing 10 uM EGCG, but adipogenesis in 3T3-L1 cells was not inhibited by EGCG treatment. For anti-tumor effects, the cancer cell lines were treated with 10 uM EGCG. PDT was significantly (p<0.05) increased in EGCG-treated SNU-601, AGS, MCF-7, and U87-MG cancer cell lines, except in MKN74 and A-549. The level of telomerase activity and cell migration capacity were significantly (p<0.05) reduced, while $SA-{\beta}-gal$ activity was highly up-regulated in EGCG treated-cancer cell lines, when compared to that in untreated cancer cell lines. Our results have demonstrated that EGCG treatment induces anti-tumor effects more efficiently as noted by decreased cell proliferation, cell migration, telomerase activity, and increased $SA-{\beta}-gal$ activity than inducing anti-aging and anti-adipogenesis. Therefore, EGCG at a specific concentration can be considered for a potential anti-tumor drug.

• Journal of Korean Neurosurgical Society
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• v.59 no.2
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• pp.106-116
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• 2016

Objective : Protein disulfide isomerase (PDI) acts as a chaperone on the cell surface, and it has been reported that PDI is associated with the tumor cell migration and invasion. The aims of this study are to investigate the anti-migration effect of bacitracin, which is an inhibitor of PDI, and the associated factor in this process. Methods : U87-MG glioma cells were treated with bacitracin in 1.25, 2.5, 3.75, and 5.0 mM concentrations. Western blot with caspase-3 was applied to evaluate the cytotoxicity of bacitracin. Adhesion, morphology, migration assays, and organotypic brain-slice culture were performed to evaluate the effect of bacitracin to the tumor cell. Western blot, PCR, and gelatin zymography were performed to investigate the associated factors. Thirty glioma tissues were collected following immunohistochemistry and Western blot. Results : Bacitracin showed a cytotoxicity in 3rd (p<0.05) and 4th (p<0.001) days, in 5.0 Mm concentration. The cell adhesion significantly decreased and the cells became a round shape after treated with bacitracin. The migration ability, the expression of phosphorylated focal adhesion kinase (p-FAK) and matrix metalloproteinase-2 (MMP-2) decreased in a bacitracin dose- and time-dependent manner. The U87-MG cells exhibited low-invasiveness in the 2.5 mM, compared with the untreated in organotypic brain-slice culture. PDI was expressed in the tumor margin, and significantly increased with histological glioma grades (p<0.001). Conclusion : Bacitracin, as a functional inhibitor of PDI, decreased the phosphorylated FAK and the secreted MMP-2, which are the downstream of integrin and play a major role in cell migration and invasion, might become one of the feasible therapeutic strategies for glioblastoma.

• Molecules and Cells
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• v.45 no.7
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• pp.479-494
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• 2022

Human mesenchymal stem cells (MSCs) are multipotent stem cells that have been intensively studied as therapeutic tools for a variety of disorders. To enhance the efficacy of MSCs, therapeutic genes are introduced using retroviral and lentiviral vectors. However, serious adverse events (SAEs) such as tumorigenesis can be induced by insertional mutagenesis. We generated lentiviral vectors encoding the wild-type herpes simplex virus thymidine kinase (HSV-TK) gene and a gene containing a point mutation that results in an alanine to histidine substitution at residue 168 (TK(A168H)) and transduced expression in MSCs (MSC-TK and MSC-TK(A168H)). Transduction of lentiviral vectors encoding the TK(A168H) mutant did not alter the proliferation capacity, mesodermal differentiation potential, or surface antigenicity of MSCs. The MSC-TK(A168H) cells were genetically stable, as shown by karyotyping. MSC-TK(A168H) responded to ganciclovir (GCV) with an half maximal inhibitory concentration (IC₅₀) value 10-fold less than that of MSC-TK. Because MSC-TK(A168H) cells were found to be non-tumorigenic, a U87-TK(A168H) subcutaneous tumor was used as a SAE-like condition and we evaluated the effect of valganciclovir (vGCV), an oral prodrug for GCV. U87-TK(A168H) tumors were more efficiently ablated by 200 mg/kg vGCV than U87-TK tumors. These results indicate that MSC-TK(A168H) cells appear to be pre-clinically safe for therapeutic use. We propose that genetic modification with HSV-TK(A168H) makes allogeneic MSC-based ex vivo therapy safer by eliminating transplanted cells during SAEs such as uncontrolled cell proliferation.

• Journal of Korean Neurosurgical Society
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• v.37 no.2
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• pp.129-136
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• 2005

Objective: Currently available therapies for human malignant gliomas have limited efficacy. Toxoplasma gondii, an obligate intracellular protozoan parasite, and Quil-A are nonspecific, potent immune stimulants. T. gondii is shown to have antitumor activity in some types of cancers. Therefore, this study is undertaken to evaluate the antitumor effect of Toxoplasma lysate antigen (TLA), alone or in combination with Quil-A, on human glioma U373MG and U87MG cells. Methods: The in vitro effects of TLA alone or in combination with Quil-A on the proliferation, invasion, and apoptosis of glioma cells were tested using MTT, Matrigel invasion, and DNA fragmentation assays, and the in vivo effects on the growth of gliomas were evaluated in athymic nude mice transplanted with glioma cells. Results: Treatment with TLA resulted in the suppressed proliferation and invasion of both U373MG and U87MG cells, in a dose-dependent manner. In addition, at high concentration, TLA induced glioma cell apoptosis. When TLA was administered in the mouse glioma model, malignant glioma growth was decreased. The combined treatment of TLA with Quil-A significantly inhibited the proliferation and invasion of cultured cells as well as tumor mass of implanted mice. Conclusion: TLA inhibits the proliferation and invasion of glioma cells in vitro and in vivo, and these antitumor effects of TLA are significantly enhanced by the addition of Quil-A.