scholarly journals OS5 - 173 Inhibition of eEF2K as a Novel Therapeutic Strategy in Neuroblastoma and Medulloblastoma

Author(s):  
A Delaidelli ◽  
D Khan ◽  
G Leprivier ◽  
SM Pfister ◽  
MD Taylor ◽  
...  

Medulloblastoma and neuroblastoma are aggressive solid pediatric tumors, with 5 year survival rates lower than 50-60%. In addition, more than 80% of the survivors develop permanent neurological impairments. Hence, there is a dire need to identify and validate novel, more effective and less toxic therapeutic approaches. Tumors are continually exposed to acute changes in the micro-environment, including nutrient availability. We previously showed that eukaryotic Elongation Factor-2 Kinase (eEF2K) is a critical regulator of cellular adaptation to acute metabolic stress. Based on those findings, we hypothesize that eEF2K is a marker of outcome and mediates medulloblastoma and neuroblastoma adaptation to acute stress. METHODS – Proprietary gene expression datasets (for medulloblastoma) and the R2 genomic analysis platform (for neuroblastoma) were analyzed for links between eEF2K expression and outcome. Effects of eEF2K knockdown on cell survival were evaluated in BE(2)C neuroblastoma cells. Immunoblotting and immunohistochemistry were performed on neuroblastoma cell lines and tissue microarrays (TMAs) for key molecules in the pathway. Similar studies are underway in medulloblastoma cell lines and TMAs. RESULTS - Low eEF2K mRNA expression is predictive of improved survival in medulloblastoma and neuroblastoma. Low p-eEF2 protein expression, indicative of low eEF2K activity, improves survival in human neuroblastoma. Neuroblastoma cell lines with eEF2K knockdown are more sensitive than controls to nutrient deprivation. CONCLUSIONS - eEF2K may represent a critical mechanism for adaptation to acute metabolic stress in neuroblastoma and medulloblastoma, and is therefore a promising therapeutic target. We are currently exploring the pharmacological inhibition of eEF2K in xenograft tumor models.

Symmetry ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1907
Author(s):  
Hideki Izumi ◽  
Yasuhiko Kaneko ◽  
Akira Nakagawara

Neuroblastoma is one of the most common childhood solid tumors and develops from neural stem cells that normally comprise the embryonic structure termed the neural crest. Human neuroblastoma cell lines have special properties as they exhibit cell growth and are induced to become mature neurons by drugs such as retinoid. Therefore, we examined asymmetric cell division (ACD) using human neuroblastoma cells as an ACD model, and confirmed that ACD in human cancer cells is evolutionally conserved. Furthermore, we demonstrated that MYCN is involved in cell division fate. We introduce the brief history of ACD study using neuroblastoma cell lines and discuss why human neuroblastoma cells are an ideal model system for clarifying the mechanism of ACD.


PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0246244
Author(s):  
Laura V. Bownes ◽  
Adele P. Williams ◽  
Raoud Marayati ◽  
Laura L. Stafman ◽  
Hooper Markert ◽  
...  

Investigation of the mechanisms responsible for aggressive neuroblastoma and its poor prognosis is critical to identify novel therapeutic targets and improve survival. Enhancer of Zeste Homolog 2 (EZH2) is known to play a key role in supporting the malignant phenotype in several cancer types and knockdown of EZH2 has been shown to decrease tumorigenesis in neuroblastoma cells. We hypothesized that the EZH2 inhibitor, GSK343, would affect cell proliferation and viability in human neuroblastoma. We utilized four long-term passage neuroblastoma cell lines and two patient-derived xenolines (PDX) to investigate the effects of the EZH2 inhibitor, GSK343, on viability, motility, stemness and in vivo tumor growth. Immunoblotting confirmed target knockdown. Treatment with GSK343 led to significantly decreased neuroblastoma cell viability, migration and invasion, and stemness. GSK343 treatment of mice bearing SK-N-BE(2) neuroblastoma tumors resulted in a significant decrease in tumor growth compared to vehicle-treated animals. GSK343 decreased viability, and motility in long-term passage neuroblastoma cell lines and decreased stemness in neuroblastoma PDX cells. These data demonstrate that further investigation into the mechanisms responsible for the anti-tumor effects seen with EZH2 inhibitors in neuroblastoma cells is warranted.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Yaoli Pu Yang ◽  
Simeng Wang ◽  
Xingguo Li ◽  
Nina F. Schor

Neuroblastoma is a childhood neural crest tumor. Fenretinide, a retinoic acid analogue, induces accumulation of mitochondrial reactive oxygen species and consequent apoptosis in neuroblastoma cells. The p75 neurotrophin receptor (p75NTR) enhances the antineuroblastoma cell efficacy of fenretinidein vitro. We examined the role of the retinoid binding protein, CRABP1, in p75NTR-mediated potentiation of the efficacy of fenretinide. Knockdown and overexpression, respectively, of either p75NTR or CRABP1 were effected in neuroblastoma cell lines using standard techniques. Expression was determined by qRT-PCR and confirmed at the protein level by Western blot. Metabolic viability was determined by Alamar blue assay. While protein content of CRABP1 correlated roughly with that of p75NTR in the three neuroblastoid or epithelioid human neuroblastoma cell lines studied, manipulation of p75NTR expression resulted in cell line-dependent, variable change in CRABP1 expression. Furthermore, in some cell lines, induced expression of CRABP1 in the absence of p75NTR did not alter cell sensitivity to fenretinide treatment. The effects of manipulation of p75NTR expression on CRABP1 expression and the effects of CRABP1 expression on fenretinide efficacy are therefore neuroblastoma cell line-dependent. Potentiation of the antineuroblastoma cell effects of fenretinide by p75NTR is not mediated solely through CRABP1.


1990 ◽  
Vol 110 (6) ◽  
pp. 2185-2193 ◽  
Author(s):  
S Dedhar ◽  
V Gray

We report the isolation from two human neuroblastoma cell lines of an Arg-Gly-Asp-dependent integrin complex capable of binding to vitronectin, fibronectin, and type I collagen. The two neuroblastoma cell lines, SK-N-SH and IMR-32, exhibit specific attachment to fibronectin and type I collagen. SK-N-SH cells exhibit a much stronger attachment to vitronectin than the IMR-32 cells, which attach poorly to this substrate. Affinity chromatography of octylglucoside extracts of 125I surface-labeled cells on GRGDSPK-Sepharose columns resulted in the specific binding and elution with GRGDSP of three radiolabeled polypeptides with relative molecular masses of 135, 115, and 90 kD when analyzed by SDS-PAGE under nonreducing conditions. In the SK-N-SH cells the 135- and 90-kD polypeptides were more abundant whereas in the IMR-32 cells the 135- and 115-kD polypeptides were more highly expressed. Liposomes prepared from fractions containing all three polypeptides bound to vitronectin, fibronectin, and type I collagen, whereas liposomes prepared from the 135- and 115-kD polypeptides bound only to fibronectin and type I collagen. Polyclonal antibodies against the alpha/beta complexes of both the vitronectin receptor and the fibronectin receptor immunoprecipitated all three polypeptides. A monoclonal antibody against beta 1 immunoprecipitated only the 135- and the 115-kD polypeptides, whereas a monoclonal antibody against beta 3 subunit immunoprecipitated the 135- and 90-kD polypeptides. Although, the 115-kD polypeptide could be recognized by an anti-beta 1 antibody, a comparison of peptide maps generated by V8 protease digestion of the 115-kD polypeptide and beta 1 subunit immunoprecipitated from GRGDSPK-Sepharose flow-through material indicated that these two polypeptides are distinct. Depletion of the 90-kD polypeptide with an anti-beta 3 monoclonal antibody did not effect the ability of the 115- and 135-kD polypeptides to bind to GRGDSPK-Sepharose. These data indicate that the SK-N-SH and IMR-32 neuroblastoma cells express a novel "beta 1-like" integrin subunit that can associate with alpha v and can bind to RGD. We propose to name this beta 1-like subunit beta n. The data reported here thus demonstrate that in these two cell lines alpha v associates with two beta subunits, beta n and beta 3, forming two heterodimers. The alpha v beta n complex mediates binding to fibronectin and type I collagen, whereas the alpha v beta 3 complex mediates binding to vitronectin.


1988 ◽  
Vol 8 (4) ◽  
pp. 1677-1683 ◽  
Author(s):  
C J Thiele ◽  
P S Cohen ◽  
M A Israel

We detected expression of the c-myb proto-oncogene, which was initially thought to be expressed in a tissue-specific manner in cells of hematopoietic lineage, in human tissues of neuronal origin. Since the level of c-myb expression declined during fetal development, we studied the regulation of its expression in human neuroblastoma cell lines induced to differentiate by retinoic acid. The expression of c-myb declined during the maturation of neuroblastoma cells, and this change was mediated by a decrease in c-myb transcription.


1992 ◽  
Vol 3 (2-3) ◽  
pp. 139-150 ◽  
Author(s):  
Jacob S. Manaster ◽  
Tony Feuerman ◽  
C. Patrick Reynolds ◽  
Charles H. Markham

Cultured human catecholaminergic and noncatecholaminergic donor cells were used in neural transplantation experiments in a rat model of Parkinson's disease. Using two different human catecholaminergic neuroblastoma cell lines, one control non-catecholaminergic neuroblastoma cell line, and one sham control (tissue culture medium), transplants were made into the striatum using a modified Ungerstedt hemiparkinsonian rat model. Significant decreases in apomorphine-induced rotational behavior were produced by two of three catecholaminergic cell lines. Grafted cells staining positively for tyrosine hydroxylase (TH) and catecholamine fluorescence indicated viable catecholamine activity in the two cell lines which produced reductions in rotational behavior. Catecholamine fluorescence was not detected in either of the two controls. These data suggest a link between catecholamine secretion by transplanted cells and motor improvement using a rat rotational behavior model.


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