Human Glioma Cell Line SHG-44 Research Articles

Synthesis, antitumor activity and preliminary structure-activity relationship of 2-aminothiazole derivatives

In this paper, we described the synthesis of 2-aminothiazole sublibrary containing methyl, bromo, phenyl or butylidene at 4- or/and 5-position of its core. All target compounds were evaluated for their antitumor activities against human lung cancer cell line H1299 and human glioma cell line SHG-44. Among the compounds screened, 4,5,6,7-tetrahydrobenzo[d]thiazole(26b) exhibited the most potent antitumor activities with IC50 values of 4.89 and 4.03 μmol/L against the two tested cell lines, respectively. Preliminary structure-activity relationship(SAR) studies of these compound were subsequently investigated.

Schidandrin B kills tumor cells by initiating apoptosis in glioma SHG-44 cells.

To observe the proliferation inhibition, cell cycle, and apoptosis of human glioma cell line SHG-44 treated with different concentration of Schidandrin B and explore the effect of Schidandrin B on glioma SHG-44 cells. Glioma SHG-44 cells were treated with Schidandrin B (0, 50, 100 or 200 μg/mL) for 24, 48, 72 and 96 h, and cells were treated with vehicle as control. Viability of cells were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) analysis; cell cycle was examined with flow cytometry assay; apoptosis was detected with annexin V assay. Bax and caspase-3 proteins expression were checked by Western blot. MTT analysis showed that viability of glioma SHG-44 cells significantly decreased after exposure to Schidandrin B for the indicated time. Flow cytometry revealed that the number of cells in the sub G1 phase was increased, however, the number of cells in G0/G1, S and G2/M phases were decreased after treatment with 50, 100 or 200 μg/mL Schidandrin B, compared with the respective control group. Annexin V analysis confirmed that apoptosis rates of the control group, 50, 100, and 200 μg/mL Schidandrin B group were 1.76%±0.47%, 13.98%±5.05%, 19.64%±5.53% and 63.28%±6.88% respectively, apoptotic rate increased significantly with dose-dependent manner, and apoptosis of cells were observed under the inverted microscope after 100 μg/mL Schidandrin B treatment. Bax and caspase-3 protein were highly expressed in Schidandrin B group compared with the control group. The apoptosis could be induced by different concentration of Schidandrin B on glioma SHG-44 cells, and the mechanism may be directly excited by Schidandrin B in glioma SHG-44 cells through activating mitochondrial pathway.

LRIG1 inhibits hypoxia-induced vasculogenic mimicry formation via suppression of the EGFR/PI3K/AKT pathway and epithelial-to-mesenchymal transition in human glioma SHG-44 cells.

Leucine-rich repeats and immunoglobulin-like domains 1 (LRIG1) is a pan-negative regulator of the epidermal growth factor receptor (EGFR) signaling pathway. The aim of this study was to investigate the underlying mechanism of LRIG1 in the regulation of vasculogenic mimicry (VM) formation in glioma cells. We constructed an enhanced green fluorescent protein plasmid (pEGFP) system, pEGFP-C1-LRIG1, for overexpression of LRIG1, and transfected it into human glioma cell line SHG-44. Under hypoxic conditions induced by CoCl2, we investigated the effects of LRIG1 overexpression on VM formation and VM-dependent malignant behaviors including migration, invasion, and proliferation. Additionally, we explored the effects of LRIG1 on the expression levels of major components of the EGFR/PI3K/AKT pathway as well as E-cadherin and vimentin. We found that LRIG1 overexpression is able to inhibit hypoxia-induced VM formation, migration, invasion, and proliferation. Furthermore, LRIG1 overexpression counteracts hypoxia-induced increase in the expression of phosphorylated EGFR (pEGFR), PI3K (pPI3K), and AKT (pAKT) and reverts hypoxia-induced alteration in E-cadherin and vimentin expression levels. In LRIG1 knockdown SHG-44 cells, however, hypoxia-induced VM formation and alteration in E-cadherin and vimentin expression levels were exacerbated. These results suggest that the inhibitory effects of LRIG1 are most likely mediated by suppression of the EGFR/PI3K/AKT pathway and epithelial-mesenchymal transition (EMT) process. Our findings provide compelling evidence implicating LRIG1 in glioma pathophysiology, suggesting that gene therapy using LRIG1 may serve as a treatment for this disease.

DAPT suppresses the proliferation of human glioma cell line SHG-44

ObjectiveTo explore the suppressing effect of γ-secretase inhibitor DAPT on proliferation of human glioma cell line SHG-44 in vitro and its mechanism. MethodsThe SHG-44 cell was treated by DAPT with different concentration. The proliferation of cells was detected by MTT assay; cell cycle and TSC of CD133+ were determined by flow cytometry analysis technique; the key factor in Notch signaling pathway (Notch-1, Delta-1, Hes-1) was measured by reverse transcrip tase-polymerase chain reaction and western blotting. ResultsDAPT inhibited the growth and proliferation of SHG-44 cells significantly(P<0.05). And the inhibiting effect on SHG-44 cells produced by DAPT showed a dose-dependent manner. DAPT increased the rate of cells in G0/G1 phase of SHG-44 cells, while it decreased the rate of cells in S phase. TSC of CD133+ was significantly reduced after DAPT treated SHG-44 cells. The expression of protein and mRNA of Notch-1, Delta-1 and Hes-1 were gradually downregulated with the increase of DAPT doses. ConclusionsDAPT can downregulate these key factor in Notch signaling pathway, reduce the TSC of CD133+ and inhibit the proliferation of SHG-44 cells.

Recombinant expression, different downstream processing of the disulfide-rich anti-tumor peptide Ranpirnase and its effect on the growth of human glioma cell line SHG-44

Ranpirnase (Onconase) is a frogspawn-derived disulfide-rich peptide with ribonuclease activity that may be used for tumor treatment. In the present study, we established an efficient approach for preparing mature ranpirnase which may be used for research and therapeutic purposes. The designed ranpirnase precursors carried a 6xHis-tag and were recombinantly expressed in Escherichia coli. After S-sulfonation, the precursors were purified by immobilized metal-ion affinity chromatography. Following removal of the tag by aminopeptidase cleavage, cyclization and in vitro oxidative refolding, the mature ranpirnase was obtained with considerable yield, and the yield of mature ranpirnase was ~50-60 mg per liter cultures. In addition, ranpirnase inhibited the growth of human glioma cells SHG-44 in a dose-dependent manner. Thus the present study has provided an efficient approach for the preparation of active ranpirnase and its analogues for future studies.

Rho/ROCK inhibitor, fasudil, suppresses glioma cell line SHG-44 progression in vitro

Objective To observe the anti-tumor effects of Rho/ROCK inhibitor,fasudil,on proliferation,migration and apoptosis of the human glioma cell line SHG-44,furthermore exploring the possible mechanism.Methods SHG-44 cells were treated with various concentrations (10,20,40,80 and 160 μmol/L) of fasudil for different durations respectively.Morphological changes of SHG-44 cells were observed under a convered phase microscope.The inhibitory rate of cell proliferation was detected by methyl thiazol tetrazolium (MTT) assay,and 50％ inhibition concentration was calculated.The migratory ability was evaluated by using wound healing assay.Apoptosis rate was assessed by flow cytometry ( FCM ).The expression level of ROCK-Ⅰ protein was detected by using Western blotting.Results Fasudil inhibited SHG-44 cell proliferation and migration,and induced cell apoptosis in a time- and concentration-dependent manner.There was significant difference between higher-concentration groups (40,80,and 160 μmol/L)and lower-concentration groups ( 10,and 20 μmol/L) or control group ( P ＜ 0.05 ).The expression of ROCK-Ⅰ was remarkably lower in higher-concentration group than in control group or lower-concentration group at the same time points ( P ＜ 0.05).Conclusion Fasudil may suppress the progression of SHG-44in vitro by inhibiting ROCK-Ⅰ and inducing apoptosis of tumor cells. Key words: Glioma; Fasudil; Rho/ROCK signaling pathway; Proliferation

The biological characteristics of glioma stem cells in human glioma cell line SHG44

Gliomas are the most common tumors of the central nervous system (CNS) and a frequent cause of death. The treatment of malignant gliomas is often palliative due to their high recurrence rate. A growing body of evidence suggests that glioma may arise from cancer stem cells (CSC) correlated with neural stem cells (NSC), with the capacity for self-renewal and multipotency. CSCs have been isolated from human gliomas and numerous other solid tumors. It is assumed that a number of established malignant cell lines also contain a rare subpopulation of stem cells. This study was designed to investigate the proportion of CSCs in the human glioma cell line SHG44 and to study the limitations of CD133 immunophenotyping in glioma stem cell research. SHG44 cells were cultured in both serum-containing and serum-free medium. The similar shape in growth curves (in the exponential growth phase) revealed that most cells participated in the population amplification. Time gradient BrdU labeling and monoclonal assay revealed that almost every single cell participated in the division growth (98.82%) and possessed the ability to form clones (96.19%). No significant difference was found in the proportions of CD133+ cells in the serum-containing and serum-free groups (38.25%/37.92%). In addition, no significant difference was noted in the proportions of CD133+ cells among monoclones selected randomly in the serum-containing group. These results suggested that CD133- cells generate CD133+ cells and have the ability to form clones. Thus, we concluded that most SHG44 cells were CSCs and serum-free medium was not necessary for the generation of CSCs. In this line, CD133- cells also possessed clonogenic, self-renewal capacities and were also CSCs.

Elevated expression of Dickkopf-1 increases the sensitivity of human glioma cell line SHG44 to BCNU

BackgroundStudies have shown that Dickkopf-1 (DKK-1) is involved in tumorigenesis. Recently, we found that 9 out of 12 human glioma cell lines had high level of DKK-1 protein while the other 3 had very low or non-detectable level of DKK-1. The aim of this study is to further examine the function of DKK-1 in glioma cells.Materials and methodsThe glioma cell line SHG44 was obtained from a patient with grade II-III astrocytoma. SHG44 cells were transfected with a human DKK-1 gene. Transfection of the empty vector pcDNA3.1 was used as negative control. Sensitivity to BCNU was measured by Annexin-V staining. Expression of bax, bcl-2 and caspase-3 of three groups was determined by immunohistochemistry.ResultsThe tranfection was confirmed by PCR, RT-PCR and Western blot. More apoptotic cell death was observed in the DKK-1 transfected cells, comparing to the non-transfected cells, or cells with empty vector. The expression of bax and caspase-3 of the SHG44 -DDK-1 increased, whereas the expression of bcl-2 decreasedConclusionOur results indicated that DKK-1 has a pro-apoptotic function of in glioma.

The effects of acetaminophen combined with radiation on the radiosensitivity of irradiated human glioma cell progeny

Objective To study the effects of acetaminophen (ACE) combined with radiation on the progeny of the human glioma cell line SHG-44, and to investigate if ACE may be an useful therapeutic radiosensitivity agent in the treatment of recurrent human glioma.