scholarly journals MODL-17. SHP2 INHIBITORS SHOW ACTIVITY AGAINST NF1-DEFICIENT GLIOMAS AND ENHANCE MAPK PATHWAY INHIBITION IN BRAF-V600E MUTANT GLIOMAS

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii414-iii414
Author(s):  
Daniel Muldoon ◽  
Guisheng Zhao ◽  
Carly Batt ◽  
Mallika Singh ◽  
Theodore Nicolaides

Abstract INTRODUCTION Activation of the RAS-MAPK signaling cascade is common in pediatric gliomas. Based on the role of SHP2 in RAS pathway signaling, we hypothesized that NF1-deficient pediatric glioma models would respond to SHP2 inhibitor monotherapy whereas BRAF-V600E gliomas would not. However, we postulated that the latter would exhibit increased sensitivity to a BRAF inhibitor (BRAFi) in combination with SHP2i. Here we demonstrate that the SHP2 inhibitors SHP099 and RMC-4550 (SHP2i) show significant single-agent activity in vitro against NF1-deficient glioma cells and that the combination of RMC-4550 with BRAFi shows increased activity in BRAF-V600E glioma cells relative to the single-agents. METHODS Using a panel of NF1 mutant/deficient and BRAF-V600E mutant glioma cell lines we examined effects on cell viability and protein expression levels of total and phosphorylated MEK, ERK, and AKT. RESULTS LN229 and U87 NF1-deficient glioma cells are sensitive to SHP2i alone but not A375 cells (melanoma, BRAF-V600E). Additionally, we show that in multiple BRAF-V600E glioma cell lines BRAFi sensitivity increases when combined with a SHP2i. Immunoblots show decreased expression of pERK and pMEK in LN229 cells following SHP2i exposure, while A375 cells maintain MAPK pathway signaling. A sustained decrease in the expression of pERK after 24 hours was observed in BRAF-V600E glioma cells with BRAFi in combination with SHP2i, consistent with relief of feedback inhibition. In vivo studies using orthotopic xenograft models are underway. CONCLUSION SHP2i shows preclinical activity in vitro against NF1-deficient pediatric glioma cell lines as a single-agent and against BRAF-V600E gliomas in combination with BRAFi.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e14043-e14043
Author(s):  
Xingchen Ding ◽  
Jinming Yu ◽  
Man Hu

e14043 Background: Hypoxia inducible factor-1α (HIF-1α) up-regulates the expression of programmed death ligand-1 (PD-L1) in some extracranial malignancies. However, whether it also increases PD-L1 expression in intracranial tumor is still unknown. Here we explored the relationship between HIF-1α and PD-L1 expression in glioma, and investigated their clinical significance. Methods: Tumor tissues from 120 patients with glioma, were analyzed for PD-L1 and HIF-1α expression using immunohistochemistry. And results were verified in vitro, using U251, U343 glioma cell lines. Gene expression were evaluated by quantitative PCR; protein levels were analyzed by Western blot; ChIP-qPCR (chromatin immunoprecipitation coupled with quantitative PCR) analysis showed the relationship between HIF-1α and PD-L1. Glioma in situ model were used to explore whether HIF-1α inhibitor (PX-478) can enhance anti-PD-L1 therapy responses. Tumor volume was measured twice weekly. Immune data were further analyzed by FACS DIVA 7.0 or Flow Jo 7.6.5 software. Results: In glioma patients, HIF-1α and PD-L1 were markedly overexpressed in high grade glioma (HGG) tissues and were both associated with poorer overall survival(OS) (PD-L1( < 5% vs. ≥ 5%): 3, 5, 10-year OS: 78.1%, 50.5%, 27.2% vs. 45.4%, 11.8%, 0%, P = 0.0026; HIF-1α( < 1% vs. ≥ 1%): 3, 5, 10-year OS:74.2%, 66.8%, 53.4% vs. 61.6%, 21.0%, 0%, P = 0.001). And the expression of PD-L1 was significantly positively correlated with the expression of HIF-1α in glioma patients ( r = 0.412, P < 0.001). In glioma cell lines, PD-L1 expression was significantly induced under hypoxia condition, but the enhanced PD-L1 expression was abrogated by either HIF-1α knock-down or HIF-1α inhibitor treatment. Furthermore, ChIP-qPCR analysis showed the direct binding of HIF-1α to PD-L1 proximal promoter, providing evidence that HIF-1α up-regulate PD-L1 expression in glioma cells. In glioma murine model, combination treatment with HIF-1α inhibitor and anti-PD-L1 antibody caused a more pronounced suppressive effect on tumor growth compared to mice treated with either single agent. Immunologically, the combination treatment improved both dendritic cell (DC) and CD8+ T cell activation. Conclusions: Multiple findings demonstrated that positive relationship between HIF-1α and PD-L1 existed in glioma cells under hypoxia condition. These observations also provide invaluable information that hypoxia contributes to a key phase of glioma cells evading adaptive immunity, thereby promoting malignant progression and poorer clinical outcomes. Given these, it would be a potential strategy to target HIF-1α in combination with the blockage of PD-1/PD-L1 pathway for anti-cancer in the future.


1990 ◽  
Vol 73 (3) ◽  
pp. 436-440 ◽  
Author(s):  
Jun-ichi Kuratsu ◽  
Yukitaka Ushio

✓ Platelet-derived growth factor (PDGF) is produced by glioma cells. However, there is heterogeneity among glioma cell lines in the production of PDGF. It has been demonstrated that U251MG cells produce a PDGF-like molecule while U105MG cells do not. Trapidil, a specific antagonist of PDGF, competes for receptor binding with PDGF. Therefore, the inhibitory effect of trapidil on the proliferation of glioma cells was investigated in vitro using two glioma cell lines. At 100 µg/ml, trapidil significantly inhibited the proliferation of U251MG cells (which produce the PDGF-like molecule). At the same trapidil concentration, the proliferation of U105MG cells (which do not produce the PDGF-like molecule) was not inhibited. The inhibitory effect of trapidil was remarkable on Days 3 and 4 of culture. After 4 days of incubation, the proliferation of U251MG cells was 46% of the control preparation. Trapidil enhanced the antitumor effect of 3-((4-amino-2-methyl-5-pyrimidinyl)ethyl)-1-(2-chloroethyl)-1-nitro-sourea (ACNU) against U251MG cells. The enhancing effect was highest on Days 4 and 6 of culture. After 6 days of incubation in the presence of 100 µg/ml trapidil and 1 µg/ml ACNU, the proliferation of U251MG cells was 18% of the control preparation. These findings suggest that trapidil interrupts the autocrine loop at the PDGF and PDGF-receptor level and that combination therapy with trapidil and ACNU may be useful in the treatment of glioma.


2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Zhen-yong Qi ◽  
Li-li Wang ◽  
Xu-liang Qu

Background. Accumulating evidence has implicated long noncoding RNAs (lncRNAs) in glioma progression. Here, we aimed to explore the potential roles of a novel lncRNA, LINC00355, in glioma and to clarify the underlying mechanisms. Methods. RT-PCR was used to examine the relative expressions of LINC00355 in glioma cell lines and specimen samples. The clinicopathological and prognostic significances of LINC00355 in glioma patients were statistically analyzed. To determine cell activities, CCK-8, clonogenic assays, flow cytometry, migration, and invasion assays were performed. Moreover, the potential mechanisms of LINC00355 were investigated by bioinformatics assays and luciferase reporter assays. Results. LINC00355 expression was increased in glioma cell lines and specimens, and higher LINC00355 expression predicted advanced clinical progress and reduced overall survival and disease-free survival in glioma patients. Functionally, LINC00355 depletion promoted cell proliferation, invasion, and migration in glioma cells and induced apoptosis of glioma cells, whereas LINC00355 upregulation resulted in the opposite effects in vitro. Mechanistic assays revealed that LINC00355 as a sponge for miR-1225 repressed fibronectin type III domain-containing 3B (FNDC3B) expressions. Conclusion. Our findings revealed the tumor-promotive roles of LINC00355 in the progression of glioma, indicating that LINC00355 exhibited ceRNA functions via modulating miR-1225/FNDC3B axis.


1994 ◽  
Vol 81 (3) ◽  
pp. 402-410 ◽  
Author(s):  
Satoshi Tanaka ◽  
Tadashi Nagashima ◽  
Shinya Manaka ◽  
Tomokatsu Hori ◽  
Shigeru Yasumoto

✓ The effect of recombinant human interleukin-1 (rHuIL-1) derivatives on human glioma cell lines was examined in vitro. Five glioma cell lines, U-251 MG, U-373 MG, U-87 MG, A-172, and T98G, were incubated in medium containing 1% fetal calf serum and various concentrations of different types of rHuIL-1: OCT-43 (rHuIL-1β), OCT-7000 (rHuIL-1α), and OCT-8000 (rHuIL-1α). The high-affinity IL-1 receptors were expressed in the U-251 MG and U-373 MG cell lines, and rHuIL-1 was found to suppress cell growth and to induce morphological differentiation of these cell lines. Growth inhibition occurred in a dose-dependent manner in concentrations or rHuIL-1 ranging between 1 and 100 ng/ml. Interestingly, rHuIL-1 induced a transient growth of glioma cells shortly after administration, then suppressed cell growth with accompanying elongation of cytoplasmic processes. This unique process of transient growth stimulation followed by growth suppression was parallel to the efficacy of bromodeoxyuridine uptake in the rHuIL-1-treated cells. Concomitantly, accumulation of glial fibrillary acidic protein and cyclic adenosine monophosphate contents was observed in four glioma cell lines. Continuous rHuIL-1 treatment for longer than 30 days elicited irreversible astrocytic terminal differentiation. These results indicate that IL-1 is an effector on the growth regulation of glioma cells, resulting in astrocytic differentiation in vitro.


2017 ◽  
Vol 37 (5) ◽  
Author(s):  
Peng Du ◽  
Haiting Zhao ◽  
Renjun Peng ◽  
Qing Liu ◽  
Jian Yuan ◽  
...  

Temozolomide (TMZ) is the most commonly used alkylating agent in glioma chemotherapy. However, growing resistance to TMZ remains a major challenge for clinicians. Recent evidence emphasizes the key regulatory roles of non-coding RNAs (lncRNAs and miRNAs) in tumor biology, including the chemoresistance of cancers. However, little is known about the role and regulation mechanisms of lncRNA cancer X-inactive specific transcripts (XIST) in glioma tumorigenesis and chemotherapy resistance. In the present study, higher XIST expression was observed in glioma tissues and cell lines, which was related to poorer clinicopathologic features and shorter survival time. XIST knockdown alone was sufficient to inhibit glioma cell proliferation and to amplify TMZ-induced cell proliferation inhibition. Moreover, XIST knockdown can sensitize TMZ-resistant glioma cells to TMZ. XIST can inhibit miR-29c expression by directly targetting TMZ-resistant glioma cells. DNA repair protein O6-methylguanine-DNA methytransferase (MGMT) plays a key role in TMZ resistance; transcription factor specificity protein 1 (SP1), a regulator of DNA mismatch repair (MMR) key protein MSH6, has been reported to be up-regulated in TMZ-resistant glioma cell lines. In the present study, we show that XIST/miR-29c coregulates SP1 and MGMT expression in TMZ-resistant glioma cell lines. Our data suggest that XIST can amplify the chemoresistance of glioma cell lines to TMZ through directly targetting miR-29c via SP1 and MGMT. XIST/miR-29c may be a potential therapeutic target for glioma treatment.


BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Michael T. C. Poon ◽  
Morgan Bruce ◽  
Joanne E. Simpson ◽  
Cathal J. Hannan ◽  
Paul M. Brennan

Abstract Background Malignant glioma cell line models are integral to pre-clinical testing of novel potential therapies. Accurate prediction of likely efficacy in the clinic requires that these models are reliable and consistent. We assessed this by examining the reporting of experimental conditions and sensitivity to temozolomide in glioma cells lines. Methods We searched Medline and Embase (Jan 1994-Jan 2021) for studies evaluating the effect of temozolomide monotherapy on cell viability of at least one malignant glioma cell line. Key data items included type of cell lines, temozolomide exposure duration in hours (hr), and cell viability measure (IC50). Results We included 212 studies from 2789 non-duplicate records that reported 248 distinct cell lines. The commonest cell line was U87 (60.4%). Only 10.4% studies used a patient-derived cell line. The proportion of studies not reporting each experimental condition ranged from 8.0–27.4%, including base medium (8.0%), serum supplementation (9.9%) and number of replicates (27.4%). In studies reporting IC50, the median value for U87 at 24 h, 48 h and 72 h was 123.9 μM (IQR 75.3–277.7 μM), 223.1 μM (IQR 92.0–590.1 μM) and 230.0 μM (IQR 34.1–650.0 μM), respectively. The median IC50 at 72 h for patient-derived cell lines was 220 μM (IQR 81.1–800.0 μM). Conclusion Temozolomide sensitivity reported in comparable studies was not consistent between or within malignant glioma cell lines. Drug discovery science performed on these models cannot reliably inform clinical translation. A consensus model of reporting can maximise reproducibility and consistency among in vitro studies.


2019 ◽  
Vol 18 ◽  
pp. 153303381882140 ◽  
Author(s):  
Ye Zhang ◽  
Rui Zhang ◽  
Rui Sui ◽  
Yi Chen ◽  
Haiyang Liang ◽  
...  

MicroRNA-374a has been abnormally expressed in several cancer types; however, its role in glioma remains unclear. Therefore, we aimed to investigate whether microR-374a participated in the progression of glioma. Expression of microR-374a in glioma cell lines and normal cell line was measured by quantitative real-time polymerase chain reaction. Luciferase reporter assay and Western blot were used to detect the targets of microR-374a. In vitro functional experiments were conducted to investigate the biological role of microR-374a. Low expression of microR-374a was found in glioma cell lines. Prokineticin 2 was identified as a direct target of microR-374a in glioma. Investigations on the mechanisms related to glioma progression showed that microR-374a inhibited glioma cell proliferation, cell cycle progression, and cell invasion through targeting Prokineticin 2. Taken together, these results revealed that microR-374a functions as tumor suppressor by targeting Prokineticin 2, suggesting it might be a novel therapeutic target for glioma.


2002 ◽  
Vol 13 (3) ◽  
pp. 1-11 ◽  
Author(s):  
Jay Jaganathan ◽  
Joshua H. Petit ◽  
Barbara E. Lazio ◽  
Satyendra K. Singh ◽  
Lawrence S. Chin

Object Tumor necrosis factor (TNF)–related apoptosis-inducing ligand (TRAIL) is a member of the TNF cytokine family, which mediates programmed cell death (apoptosis) selectively in tumor cells. The selective tumoricidal activity of TRAIL is believed to be modulated by agonistic (DR4 and DR5) and antagonistic receptors (DcR1 and DcR2), which appear to compete for ligand binding. Because TRAIL is expressed in a wide range of tissues, including brain, kidney, and spleen, and seems consistently to induce cell death in tumor cells, the cytokine has been identified as a promising approach for selectively inducing tumor cell death. In this study, the authors examine the importance of TRAIL's receptors in both its selectivity for tumor cells and its ability to induce apoptosis. Methods The authors first examined sensitivity to TRAIL and expression of TRAIL receptors in four established and four primary cultured glioma cell lines by using viability and fluorescent apoptosis assays. They then evaluated DR5 expression and JNK, caspase 3, and caspase 7 activation by conducting immunoblot analyses. Reverse transcriptase–polymerase chain reaction (RT-PCR) was performed to study expression of DR4, DR5, DcR1, and DcR2. The DR5 transcripts from one TRAIL-sensitive, one partially TRAIL-resistant, and one TRAIL-resistant cell line were subsequently sequenced. The expression of TRAIL receptors in normal and glial brain tumor pathological specimens were then compared using immunohistochemistry. Finally, to study the direct effects of DR5 on glioma cells, the authors conducted transient and stable transfections of the fulllength DR5 transcript into glioma cells with and without preestablished overexpression of the antiapoptotic gene bcl-2. The established glioma cell lines T98G and U87MG, and all primary cell lines, were apoptotic at greater than or equal to 100 ng/ml TRAIL. The A172 cells, by contrast, were susceptible only with cycloheximide, whereas U373MG cells were not susceptible to TRAIL. The JNK, caspase 3, and caspase 7 activity evaluated after treatment with TRAIL showed that TRAIL-sensitive cell lines exhibited downstream caspase activation, whereas TRAIL-resistant cells did not. The DR5 sequences in T98G, A172, and U373MG cell lines were identical to published sequences despite these differences in sensitivity to TRAIL. The RT-PCR performed on extracts from the eight glioma cell lines showed that all expressed DR5. Immunohistochemistry revealed ubiquitous expression of DR5 in glioma specimens, with an associated lack of decoy receptor expression. Normal brain specimens, by contrast, stained positive for both DR5 and DcR1. Overexpression of DR5 under both transfection conditions resulted in cell death in all three cell lines. The previously seen resistance of U373 cells to TRAIL was not observed. Apoptotic cell death was confirmed using DNA fragmentation in T98G cell lines and fluorescent miscroscopy in all cell lines. The T98G cells stably transfected with bcl-2 before DR5 overexpression were protected from cell death. Conclusions The authors conclude that DR5 represents a promising new approach to directly activating the intrinsic caspase pathway in glioma cells. The fact that TRAIL-resistant gliomas do not express decoy receptors suggests a mechanism of resistance unique from that proposed for normal tissues. The overexpression of DR5 induced apoptotic cell death in glioma cells without TRAIL and was able to overcome the resistance to TRAIL demonstrated in U373 cells. The Bcl-2 protects cells from DR5 by acting downstream of the receptor, most likely at the level of caspase activation.


1998 ◽  
Vol 88 (3) ◽  
pp. 529-534 ◽  
Author(s):  
Shiro Isoe ◽  
Hirofumi Naganuma ◽  
Shin Nakano ◽  
Atsushi Sasaki ◽  
Eiji Satoh ◽  
...  

Object. The aim of this study was to investigate the mechanism by which malignant glioma cells escape from growth inhibition mediated by transforming growth factor-β (TGF-β), a ubiquitous cytokine that inhibits cell proliferation by causing growth arrest in the G1 phase of the cell cycle. Methods. The authors measured the response of eight malignant glioma cell lines to the growth-inhibiting activity of TGF-β in vitro and the expression of TGF-β Types I and II receptors in malignant glioma cells. The effect of TGF-β on the expression of a p27Kip1 cyclin-dependent kinase inhibitor was also investigated to assess the downstream signal transmission from TGF-β receptors. All malignant glioma cell lines were insensitive to growth inhibition by TGF-β1 and TGF-β2. Analyses of TGF-β receptors by means of affinity labeling in which 125I-TGF-β1 was used showed that six glioma lines had both TGF-β Types I and II receptors on their cell surfaces, whereas two lines had very small amounts of TGF-β Type I and/or Type II receptors. Northern blot analysis showed that all tumor lines expressed variable levels of messenger RNAs for both TGF-β Types I and II receptors. Flow cytometric analyses revealed that treatment of malignant glioma cells with TGF-β1 significantly downregulated the expression of p27Kip1 protein in all malignant glioma cell lines except one. Conclusions. The authors suggest that most malignant glioma cells express TGF-β Types I and II receptors, which can transmit some signals downstream and that the loss of response to TGF-β growth inhibition may not be caused by an abnormality of the TGF-β receptors.


1995 ◽  
Vol 82 (6) ◽  
pp. 1035-1043 ◽  
Author(s):  
Jörg-Christian Tonn ◽  
Hans Kristian Haugland ◽  
Jaakko Saraste ◽  
Klaus Roosen ◽  
Ole Didrik Laerum

✓ The aim of this study was to investigate the antimigratory and antiinvasive potential of vincristine sulfate (VCR) on human glioma cells and to analyze whether phenytoin (5,5-diphenylhydantoin; DPH) might act synergistically with VCR. Vincristine affects the cytoplasmic microtubules; DPH has been reported to enhance VCR cytotoxicity in murine cells. In two human glioma cell lines, GaMG and D-37MG, we found VCR to reduce monolayer growth and colony formation in a dose-dependent fashion at concentrations of 10 ng/ml and above. Phenytoin increased the cytotoxic and cystostatic effects of VCR in monolayer cells but not in spheroids. Multicellular spheroids were used to investigate directional migration. A coculture system of GaMG and D-37MG spheroids with fetal rat brain aggregates was used to analyze and quantify tumor cell invasion. A dose-dependent inhibition of migration and invasion by VCR was observed in both cell lines without further enhancement by DPH. Immunofluorescence microscopy with antibodies against α-tubulin revealed dose-dependent morphological alterations in the microtubules when the cells were exposed to VCR but not after incubation with DPH. Based on the combination of standardized in vitro model systems currently in use and the present data, the authors strongly suggest that VCR inhibits migration and invasion of human glioma cells. This is not altered by DPH, which inhibits cell proliferation in combination with VCR.


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