Using CD133 positive U251 glioblastoma stem cells to establish nude mice model of transplanted tumor

Small-sized gadolinium oxide based nanoparticles for high-efficiency theranostics of orthotopic glioblastoma

Glioblastoma (GBM) is one of the most malignant tumors with poor prognosis and outcomes. Although smaller particle size can lead to higher blood-brain barrier (BBB)-permeability of the nanomaterials, most of the reported BBB-crossable nanomaterials for targeted GBM therapy are larger than 24 nm. To realize theranostics of GBM, co-loading of therapeutic and diagnostic agents on the same nanomaterials further results in larger particle size. In this study, we developed a kind of novel BBB-transportable nanomaterials smaller than 14 nm for high-efficiency theranostics of GBM (i.e., high contrast magnetic resonance imaging (MRI) and radiosensitization of GBM). Typically, poly(acrylic acid) (PAA) stabilized extremely small gadolinium oxide nanoparticles with modification of reductive bovine serum albumin (ES-GON-rBSA) was synthesized in water phase, resulting in excellent water-dispersibility. RGD dimer (RGD2, Glu-{Cyclo[Arg-Gly-Asp-(D-Phe)-Lys]}2) and lactoferrin (LF) were then conjugated to the ES-GON-rBSA to obtain composite nanoparticle ES-GON-rBSA-LF-RGD2 with extraordinary relaxivities (r1 = 60.8 mM-1 s-1, r2/r1 = 1.1). The maximum signal enhancement (ΔSNR) for T1-weighted MRI of tumors reached up to 423 ± 42% at 12 h post-injection of ES-GON-rBSA-LF-RGD2, which is much higher than commercial Gd-chelates (<80%). ES-GON-rBSA-LF-RGD2 exhibited high biocompatibility and can transport across the in vitro BBB model and the in vivo BBB of mice due to its small particle size (dh = 13.4 nm) and LF receptor mediated transcytosis. Orthotopic GBM studies reinforce that ES-GON-rBSA3-LF-RGD2 can accumulate in the orthotopic GBM and enhance the radiation therapy of GBM as an effective radiosensitizing agent.

Circular RNA circMAN2B2 facilitates glioma progression by regulating the miR-1205/S100A8 axis

The aim of this study was to research the mechanism of circMAN2B2 in the development of glioma. In our study, we found that circMAN2B2 has a higher expression in glioma tissues and cells, which was negatively related to the overall survival of glioma patients. The cell counting kit-8 assay, 5-ethynyl-2'-deoxyuridine labeling assay, transwell assay, and the nude mice assay indicated that knockdown of circMAN2B2 inhibited the cell proliferation, invasion, migration and decreased tumor size. In terms of mechanism, knockdown of circMAN2B2 increased the expression of miR-1205. Moreover, circMAN2B2 regulated S100A8 expression by inhibiting miR-1205. We also showed that knockdown of S100A8 inhibited cell proliferation, invasion, and migration. Increasing S100A8 expression rescued the effect of si-circMAN2B2. In conclusion, circMAN2B2 could improve cell proliferation, invasion, and migration of the glioma by inhibiting miR-1205 and promoting the expression of S100A8.

Emodin induced necroptosis in the glioma cell line U251 via the TNF-α/RIP1/RIP3 pathway

Emodin, an anthraquinone compound extracted from rhubarb and other traditional Chinese medicines, has been proven to have a wide range of pharmacological effects, such as anti-inflammatory, antiviral, and antitumor activities. Previous studies have confirmed that emodin has inhibitory effects on various solid tumors, such as osteosarcoma, liver cancer, prostate cancer and glioma. This study aimed to investigate the effects and mechanisms of emodin-induced necroptosis in the glioma cell line U251 by targeting the TNF-α/RIP1/RIP3 signaling pathway. We found that emodin could significantly inhibit U251 cell proliferation, and the viability of U251 cells treated with emodin was reduced in a dose- and time-dependent manner. Flow cytometry assays and Hoechst-PI staining assays showed that emodin induced apoptosis and necroptosis. Real-time PCR and western blot analysis showed that emodin upregulated the levels of TNF-α, RIP1, RIP3 and MLKL. Furthermore, the RIP1 inhibitor Nec-1 and the RIP3 inhibitor GSK872 attenuated the killing effect of emodin on U251 cells. In addition, emodin could increase the levels of TNF-α, RIP1, RIP3 and MLKL in vivo. The results demonstrate that emodin could induce necroptosis in glioma possibly through the activation of the TNF-α/RIP1/RIP3 axis. These studies provide novel insight into the induction of necroptosis by emodin and indicate that emodin might be a potential candidate for treating glioma through the necroptosis pathway.

Difference in the Inhibitory Effect of Temozolomide on TJ905 Glioma Cells and Stem Cells

This study aims to determine the difference in the inhibitory effect of temozolomide (TMZ) on TJ905 glioma cells and stem cells. TJ905 cancer stem cells were isolated. Livin is a member of the inhibitor of apoptosis protein family. The TJ905 cells and cancer stem cells were transfected with a Livin-shRNA and negative-shRNA, respectively, and then treated with TMZ. At 48 h post-transfection, a cell counting kit 8 assay, flow cytometry, and real-time qPCR were performed to detect cell proliferation, the cell cycle, and the expression of the Caspase-3, -7, and -9 mRNAs, respectively. As a result, the suppressive effect of TMZ on TJ905 cells was more significant than its effect on TJ905 cancer stem cells. TMZ exerted an inhibitory effect on the growth of TJ905 glioma cells by arresting them at G0/G1 phase and arresting cancer stem cells at S phase in a dose-dependent manner. TMZ inhibited Livin mRNA expression and increased the expression of the Caspase-3, -7, and -9 mRNAs. Low Livin mRNA expression induced high levels of Caspase-3, -7, and -9 expressions, thus promoting the apoptosis of both TJ905 cells and cancer stem cells in response to TMZ treatment. The TJ905 cells transfected with the Livin-shRNA were more sensitive to TMZ, whereas the TJ905 glioma stem cells transfected with the Livin-shRNA showed no significant changes in their sensitivity to TMZ. In conclusion, the Livin gene may play an important role in the resistance mechanisms of TJ905 glioma cells and cancer stem cells. However, Livin had a more distinct role in TMZ resistance, cell proliferation, and the cell cycle in TJ905 glioma cells than in cancer stem cells.

Antischistosomiasis Liver Fibrosis Effects of Chlorogenic Acid through IL-13/miR-21/Smad7 Signaling Interactions In Vivo and In Vitro

This study investigated the antischistosomiasis liver fibrosis effects of chlorogenic acid (CGA) on interleukin 13 (IL-13)/microRNA-21 (miR-21)/Smad7 signaling interactions in the hepatic stellate LX2 cell line and schistosome-infected mice. The transfection was based on the ability of the GV273-miR-21-enhanced green fluorescent protein (EGFP) and GV369-miR-21-EGFP lentiviral system to up- or downregulate the miR-21 gene in LX2 cells. The mRNA expression of miR-21, Smad7, and connective tissue growth factor (CTGF) and the protein expression of Smad7, CTGF, Smad1, phosphor-Smad1 (p-Smad1), Smad2, p-Smad2, Smad2/3, p-Smad2/3, transforming growth factor β (TGF-β) receptor I, and α-smooth muscle actin (α-SMA) was assayed. Pathological manifestation of hepatic tissue was assessed for the degree of liver fibrosis in animals. The results showed that CGA could inhibit the mRNA expression of miR-21, promote Smad7, and inhibit CTGF mRNA expression. Meanwhile, CGA could significantly lower the protein levels of CTGF, p-Smad1, p-Smad2, p-Smad2/3, TGF-β receptor I, and α-SMA and elevate the Smad7 protein level. In vivo, with treatment with CGA, the signaling molecules of IL-13/miR-21/Smad7 interactions were markedly regulated. CGA could also reduce the degree of liver fibrosis in pathological manifestations. In conclusion, CGA could inhibit schistosomiasis-induced hepatic fibrosis through IL-13/miR-21/Smad7 signaling interactions in LX2 cells and schistosome-infected mice and might serve as an antifibrosis agent for treating schistosomiasis liver fibrosis.

Relationship between microvessel density and cancer stem cells in tumor angiogenesis: a meta-analysis

Aim: Several studies have shown that cancer stem cells (CSCs) promote tumor angiogenesis and are involved in tumor growth. A meta-analysis was conducted to evaluate the association between cancer stem cell markers expression and microvessel density (MVD). Methods: Relevant literature was identified from diverse databases. The Stata 12.0 and Review Manager 5.3 software were used to performed meta-analysis. Results: Sixteen studies investigating the correlation between CSCs and tumor angiogenesis were included in a total of 1409 cases. The result showed that positive CSC markers expression were associated with increased MVD count in human tumors and CSC-transplanted mouse tumor models (p < 0.0001). Conclusion: CSCs may be associated with angiogenesis during the growth and development of tumors.

Effect of Corilagin on the Proliferation and NF-κB in U251 Glioblastoma Cells and U251 Glioblastoma Stem-Like Cells

Background. This study is to explore the effect of corilagin on the proliferation and NF-κB signaling pathway in U251 glioblastoma cells and U251 glioblastoma stem-like cells. Methods. CD133 positive U251 glioblastoma cells were separated by immunomagnetic beads to isolate glioblastoma stem-like cells. U251 cells and stem-like cells were intervened by different corilagin concentrations (0, 25, 50, and 100 μg/mL) for 48 h, respectively. Cell morphology, cell counting kit-8 assay, flow cytometry, dual luciferase reporter assay, and a western blot were used to detect and analyze the cell proliferation and cell cycle and investigate the expression of IKBα protein in cytoplasm and NF-κB/p65 in nucleus. Results. Corilagin inhibited the cell proliferation of U251 cells and their stem-like cells and the inhibition role was stronger in U251 stem-like cells (P < 0.05). The cell cycle was arrested at G2/M phase in the U251 cells following corilagin intervention; the proportion of cells in G2/M phase increased as the concentration of corilagin increased (P < 0.05). The U251 stem-like cells were arrested at the S phase following treatment with corilagin; the proportion of cells in the S phase increased as the concentration of corilagin increased (P < 0.05). The ratio of dual luciferase activities of U251 stem-like cells was lower than that of U251 cells in the same corilagin concentration. With increasing concentrations of corilagin, the IKBα expression in cytoplasm of U251 cells and U251 stem-like cells was increased, but the p65 expression in nucleus of U251 cells and U251 stem-like cells was decreased (P < 0.05). Conclusion. Corilagin can inhibit the proliferation of glioblastoma cells and glioblastoma stem-like cells; the inhibition on glioblastoma stem-like cell proliferation is stronger than glioblastoma cells. This different result indicates that the effect of corilagin on U251 cells and U251 stem-like cells may have close relationships with mechanism of cell cycle and NF-κB signaling pathway; however, the real antitumor mechanism of corilagin is not yet clear and requires further study.

Targeting a Plk1-Controlled Polarity Checkpoint in Therapy-Resistant Glioblastoma-Propagating Cells

The treatment of glioblastoma (GBM) remains challenging in part due to the presence of stem-like tumor-propagating cells that are resistant to standard therapies consisting of radiation and temozolomide. Among the novel and targeted agents under evaluation for the treatment of GBM are BRAF/MAPK inhibitors, but their effects on tumor-propagating cells are unclear. Here, we characterized the behaviors of CD133(+) tumor-propagating cells isolated from primary GBM cell lines. We show that CD133(+) cells exhibited decreased sensitivity to the antiproliferative effects of BRAF/MAPK inhibition compared to CD133(-) cells. Furthermore, CD133(+) cells exhibited an extended G2-M phase and increased polarized asymmetric cell divisions. At the molecular level, we observed that polo-like kinase (PLK) 1 activity was elevated in CD133(+) cells, prompting our investigation of BRAF/PLK1 combination treatment effects in an orthotopic GBM xenograft model. Combined inhibition of BRAF and PLK1 resulted in significantly greater antiproliferative and proapoptotic effects beyond those achieved by monotherapy (P < 0.05). We propose that PLK1 activity controls a polarity checkpoint and compensates for BRAF/MAPK inhibition in CD133(+) cells, suggesting the need for concurrent PLK1 inhibition to improve antitumor activity against a therapy-resistant cell compartment.

Pathological features of transplanted tumor established by CD133 positive TJ905 glioblastoma stem-like cells

BACKGROUND

This study is to explore the pathological features of transplanted tumor established by CD133 positive TJ905 glioblastoma stem-like cells.

METHODS

CD133 positive TJ905 glioma cells were separated by immunomagnetic beads to isolate glioma stem-like cells. TJ905 cells and stem-like cells were inoculated subcutaneously into the mice to establish model of transplanted tumor, respectively. Mice growing condition and behavior were observed. HE staining assay, immunohistochemical assay for GFAP, Ki-67 and Olig-2, and CD34 marked microvascular density (MVD) test were performed.

RESULTS

The growing condition and behavior of mice in TJ905 stem cell group was more exaggerated and the models showed stronger malignant features pathologically than that in TJ905 cell group. Glial fibrillary acidic protein (GFAP) in TJ905 cell and stem-like cell group showed the transplanted tumor originated from astrocytes. Expression of Ki-67 and oligodendrocyte transcription factor-2 (Olig-2) in TJ905 stem cells was higher notably and CD34 expression in stem cell group was significantly higher than that in the other two groups.

CONCLUSIONS

Pathological features of transplanted tumor established by CD133 positive glioblastoma stem-like cells show more malignant. Use of TJ905 stem cells to establish transplanted tumor model in nude mice is excellent for glioma research.

The cyclin-like protein Spy1 regulates growth and division characteristics of the CD133+ population in human glioma

The heterogeneity of brain cancers, as most solid tumors, complicates diagnosis and treatment. Identifying and targeting populations of cells driving tumorigenesis is a top priority for the cancer biology field. This is not a trivial task; considerable variance exists in the driving mutations, identifying markers, and evolutionary pressures influencing initiating cells in different individual tumors. Despite this, the ability to self-renew and differentiate must be conserved to reseed a heterogeneous tumor mass. Focusing on one example of a tumor-initiating cell population, we demonstrate that the atypical cyclin-like protein Spy1 plays a role in balancing the division properties of glioma cells with stemness properties. This mechanistic insight may provide new opportunities for therapeutic intervention of brain cancer.

The ultrastructural difference between CD133-positive U251 glioma stem cells and normal U251 glioma cells

Glioma stem cells (GSC) have higher tumorigenic potential and stronger chemoresistance and radioresistance than normal glioma cells. The mechanisms behind these phenomena have remained elusive. The authors have isolated CD133-positive U251 GSCs from U251 glioma cells and detected the expression of stem cell markers (CD133 and nestin) of U251 GSCs by immunofluorescence staining. Then the ultrastructures of U251 GSCs and normal U251 glioma cells were observed by transmission electron microscopy and the ultrastructural differences between them were compared. Increased cell nucleus atypia, rougher endoplasmic reticulum, and more microvilli were observed in CD133-positive U251 GSCs than in normal U251 glioma cells. In summary, these ultrastructural differences support the hypothesis that GSCs have stronger tumorigenic ability and resistance to chemotherapy and radiotherapy.

Anti-inflammatory and anti-oxidative effects of corilagin in a rat model of acute cholestasis

Background

Nowadays, treatments for cholestasis remain largely nonspecific and often ineffective. Recent studies showed that inflammatory injuries and oxidative stress occur in the liver with cholestasis. In this study, we would use corilagin to treat the animal model of acute cholestasis in order to define the activity to interfere with inflammation-related and oxidative stress pathway in cholestatic pathogenesis.

Methods

Rats were administrated with alpha-naphthylisothiocyanate to establish model of cholestasis and divided into corilagin, ursodeoxycholic acid, dexamethasone, model and normal groups with treatment of related agent. At 24h, 48h and 72h time points after administration, living condition, serum markers of liver damage, pathological changes of hepatic tissue, nuclear factor (NF)-kappaB, myeloperoxidase (MPO), malondialdehyde (MDA), superoxide dismutase (SOD) and nitric oxide (NO) were examined and observed.

Results

Compared to model group, corilagin had remarkable effect on living condition, pathological manifestation of liver tissue, total bilirubin, direct bilirubin, (P<0.01), but no effect on alanine aminotransferase (ALT) and aspartate aminotransferase (AST). With corilagin intervention, levels of MPO, MDA and translocation of NF-κB were notably decreased, and levels of SOD and NO were markedly increased (P<0.05 or P<0.01).

Conclusions

It is shown that corilagin is a potential component to relieve cholestasis through inflammation-related and oxidation-related pathway.

Preliminary Exploration on Anti-Fibrosis Effect of Kaempferol in Mice with Schistosoma Japonicum Infection

This study is to explore the effectiveness and mechanism of kaempferol on treatment of hepatic fibrosis induced by schistosoma egg. Thirty-six healthy male balb/c mice were randomly divided into 6 groups, including negative group, positive group, and 4 different dosages of kaempferol treatment groups. Each mouse was infected with 20 schistosoma Cercariae japonicum, except the ones in the negative group. Four weeks later, every infected mouse was administrated with 500mg/kg/day praziquantel for 2 days, and all kaempferol groups were followed by a 4-week administration of kaempferol with 5, 10, 15 and 20mg/kg/day respectively, while both control groups were administrated with normal saline. AH the mice were sacrificed on the 59th day after infection. The liver tissues were taken for Masson staining to detect collagen and real-time quantitative PCR to detect the mRNA expression of IL-13, collagen 1 and MMP-2. As a result, Masson stain showed that the optical density of the interested region in the positive group was significantly higher than that in the negative group (P<0.01), and the optical density in all kaempferol groups was significantly lower than that in the positive group (P<0.05 or P<0.01). Real-time PCR showed that the mRNA expression of IL-13 in the positive group was significantly higher than that in the negative group (P<0.01), and the expression of IL-13 in the 20mg/kg and 15mg/kg kaempferol groups was significantly lower than that in the positive group, respectively (P<0.05). The mRNA expression of collagen 1 in the positive group was significantly higher than that in the negative group (P<0.01), and mRNA expression of collagen 1 in the 20mg/kg kaempferol group was significantly lower than that in the positive group (P<0.05). There were no significant differences between the positive and negative groups on mRNA expression of MMP-2. The mRNA expression of MMP-2 in all kaempferol groups was significantly higher than that in the positive group (P<0.05 or P<0.01). In conclusion, kaempferol can ameliorate schistosoma egg-induced hepatic fibrosis via regulating the IL-13 signal pathway. Kaempferol is very likely to be an IL-13 targeted anti-fibrosis medicine.

Activity of Corilagin on Post-Parasiticide Liver Fibrosis in Schistosomiasis Animal Model

This study investigates the effects and possible molecular mechanisms of corilagin extraction on prevention of Schistosoma japonicum ova-induced granulomas and liver fibrosis. As a result, under a light microscope, when compared to a model group, the corilagin group showed smaller granulomas, less liver cell denaturation and less inflammatory cell infiltration, and the connective tissues were significantly decreased. By Masson staining, the liver sections from the corilagin group showed less collagen distributed around granulomas, decreased liver fibrosis in the portal tracts and less formed interlobular tissue. The expression of hydroxyproline, IL-13 in liver and GATA3 in spleen in the model group was significantly higher than that in the normal group (P<0.05 or 0.01), while the level of hydroxyproline, IL-13 and GATA3 in the corilagin group were significantly lower than that in the model group (P<0.05). In conclusion, corilagin extraction can decrease the level of Th2-associated profibrotic cytokine IL-13, and down-regulate the transcription of GATA3 mRNA in spleen cells, which alleviate the hepatic fibrosis caused by egg granuloma in Schistosoma japonicum infection.

Selective uptake of boronophenylalanine by glioma stem/progenitor cells

The success of boron neutron capture therapy (BNCT) depends on the amount of boron in cells and the tumor/blood and tumor/(normal tissue) boron concentration ratios. For the first time, measurements of boron uptake in both stem/progenitor and differentiated glioma cells were performed along with measurements of boron biodistribution in suitable animal models. In glioma stem/progenitor cells, the selective accumulation of boronophenylalanine (BPA) was lower, and retention of boron after BPA removal was longer than in differentiated glioma cells in vitro. However, boron biodistribution was not statistically significantly different in mice with xenografts.

Human brain glioma stem cells are more invasive than their differentiated progeny cells in vitro

Glioma, the most commonly occurring primary intracranial tumor, remains associated with a dismal outcome, despite the availability of multimodal therapies. Recently, however, the identification of brain glioma stem cells (BGSC) has opened up new avenues for research. BGSC are now accepted as the progenitor cells of gliomas and are thought to determine the biological features of the resulting tumors. Thus, the diffuse invasiveness of gliomas should also be theoretically driven by BGSC. However, little research effort has been directed at understanding the invasiveness of BGSC. In the present study, BGSC from eight surgical glioma specimens were cultured and identified. Using Matrigel invasion assays, the invasiveness of these cells was measured and compared with that of their respective differentiated progeny cells in vitro. For all eight clinical specimens, the BGSC were significantly more invasive than their differentiated progeny cells. These findings indicate a key role for BGSC in glioma infiltration and invasion. We also found that BGSC tended to aggregate and reform into new spheres after travelling into the Matrigel, preserving some of the morphological characteristics of the suspended cells. The invasiveness of the BGSC did not correlate with the pathological grade of glioma in the present study, so further investigations using larger sample sizes are needed to better understand the mechanisms underlying the invasiveness of BGSC.