scholarly journals FSMP-13. HYPOXIC REGULATION OF LACTATE DEHYDROGENASE GENES (LDHA/B) IN T98 GLIOBLASTOMA MULTIFORME CELLS

2021 ◽  
Vol 3 (Supplement_1) ◽  
pp. i18-i18
Author(s):  
Brian E White ◽  
Russell J Buono
Keyword(s):  
Lactate Dehydrogenase ◽  
Glioblastoma Multiforme ◽  
Gel Electrophoresis ◽  
Therapeutic Strategies ◽  
Qrt Pcr ◽  
Hypoxic Induction ◽  
Hypoxic Tumor ◽  
Native Gel ◽  
Ldh Isoforms ◽  
Ldha Gene

Abstract Glioblastoma multiforme (GBM) is the most common primary brain cancer and carries a poor prognosis. GBM cells exhibit extensive metabolic alterations that enhance survival and proliferation in the mixed normoxic-hypoxic tumor microenvironment. Lactate dehydrogenase (LDH) enzymes are critical mediators of the normoxic to hypoxic transition in cells. Two LDH genes (A/B) encode monomers that combine to form five isoenzymes (LDH1-5) with different properties for pyruvate to lactate interconversion. Hypoxic induction of LDHA in all cells appears to occur via HIF-1 mediated transcription. However, little is known about hypoxic regulation of LDHB in cancer. We report on hypoxic regulation of LDHA/B in T98G, a rare cell line that has both normal and neoplastic features. Human T98 GBM cell lines were cultured in a humidified incubator at 37° C and 5% CO2 and were grown in normoxia (21% O2) or hypoxia (95% N2, 5% C02) for 72 hours. Relative expression of LDH isoforms 1-5 was assessed using native gel electrophoresis. Expression of the LDHA and LDHB genes was measured using qRT-PCR. LDHA-dominant isoforms (4/5) were detected in T98G cells subjected to normoxia and hypoxia via gel electrophoresis, however, LDHB-dominant isoforms (1/2) were not. The LDHA/B-equimolar isoform (3) was decreased in T98G cells subjected to hypoxia. LDHA gene expression was over two-fold greater than LDHB in normoxia (p = .00256 by one-tailed Mann-Whitney U test), and over nine-fold greater in hypoxia (p = .00256). LDHA:LDHB expression in hypoxia compared to normoxia was significantly different (p = .00256). LDHA expression increased three-fold in hypoxia (p = .00256), while LDHB expression decreased 0.3-fold in hypoxia (p = .03288). We document LDHB dysregulation in T98G cells as the gene is minimally responsive to oxygen. Therapeutic strategies aimed at promoting LDHB expression may complement inhibition of LDHA and reduce GBM survival in hypoxia.

scholarly journals Knockdown ofAKT3(PKBγ) andPI3KCASuppresses Cell Viability and Proliferation and Induces the Apoptosis of Glioblastoma Multiforme T98G Cells

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Monika Paul-Samojedny ◽  
Renata Suchanek ◽  
Paulina Borkowska ◽  
Adam Pudełko ◽  
Aleksander Owczarek ◽  
...  
Keyword(s):  
Glioblastoma Multiforme ◽  
Cell Viability ◽  
Poor Prognosis ◽  
Therapeutic Strategy ◽  
Inhibitory Effect ◽  
Therapeutic Strategies ◽  
Human Brain Tumor ◽  
Qrt Pcr ◽  
Wide Range ◽  
Human Gbm

Glioblastoma multiforme (GBM) is the most malignant and invasive human brain tumor that is difficult to treat and has a very poor prognosis. Thus, new therapeutic strategies that target GBM are urgently needed. The PI3K/AKT/PTEN signaling pathway is frequently deregulated in a wide range of cancers. The present study was designed to examine the inhibitory effect ofAKT3orPI3KCAsiRNAs on GBM cell growth, viability, and proliferation.T98G cells were transfected withAKT3and/orPI3KCAsiRNAs. AKT3 and PI3KCA protein-positive cells were identified using FC and Western blotting. The influence of specific siRNAs on T98G cell viability, proliferation, cell cycle, and apoptosis was evaluated as well using FC. Alterations in the mRNA expression ofAKT3,PI3KCA, and apoptosis-related genes were analyzed using QRT-PCR. Knockdown ofAKT3and/orPI3KCAgenes in T98G cells led to a significant reduction in cell viability, the accumulation of subG1-phase cells and, a reduced fraction of cells in the S and G2/M phases. Additionally, statistically significant differences in the BAX/BCL-2 ratio and an increased percentage of apoptotic cells were found. The siRNA-inducedAKT3andPI3KCAmRNA knockdown may offer a novel therapeutic strategy to control the growth of human GBM cells.

scholarly journals The ldhA Gene Encoding Fermentative L-Lactate Dehydrogenase in Corynebacterium glutamicum Is Positively Regulated by the Global Regulator GlxR

2021 ◽  
Vol 9 (3) ◽  
pp. 550
Author(s):  
Koichi Toyoda ◽  
Masayuki Inui
Keyword(s):  
Lactate Dehydrogenase ◽  
Binding Site ◽  
Corynebacterium Glutamicum ◽  
Lactate Production ◽  
Exponential Phase ◽  
Aerobic Bacterium ◽  
Global Regulator ◽  
Gene Encoding ◽  
Fermentation Products ◽  
Ldha Gene

Bacterial metabolism shifts from aerobic respiration to fermentation at the transition from exponential to stationary growth phases in response to limited oxygen availability. Corynebacterium glutamicum, a Gram-positive, facultative aerobic bacterium used for industrial amino acid production, excretes L-lactate, acetate, and succinate as fermentation products. The ldhA gene encoding L-lactate dehydrogenase is solely responsible for L-lactate production. Its expression is repressed at the exponential phase and prominently induced at the transition phase. ldhA is transcriptionally repressed by the sugar-phosphate-responsive regulator SugR and L-lactate-responsive regulator LldR. Although ldhA expression is derepressed even at the exponential phase in the sugR and lldR double deletion mutant, a further increase in its expression is still observed at the stationary phase, implicating the action of additional transcription regulators. In this study, involvement of the cAMP receptor protein-type global regulator GlxR in the regulation of ldhA expression was investigated. The GlxR-binding site found in the ldhA promoter was modified to inhibit or enhance binding of GlxR. The ldhA promoter activity and expression of ldhA were altered in proportion to the binding affinity of GlxR. Similarly, L-lactate production was also affected by the binding site modification. Thus, GlxR was demonstrated to act as a transcriptional activator of ldhA.

scholarly journals Friend or Foe: Paradoxical Roles of Autophagy in Gliomagenesis

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1411
Author(s):  
Don Carlo Ramos Batara ◽  
Moon-Chang Choi ◽  
Hyeon-Uk Shin ◽  
Hyunggee Kim ◽  
Sung-Hak Kim
Keyword(s):  
Brain Tumor ◽  
Glioblastoma Multiforme ◽  
Cancer Biology ◽  
Molecular Mechanisms ◽  
Primary Brain Tumor ◽  
Molecular Target ◽  
Therapeutic Strategies ◽  
Homeostatic Mechanism ◽  
Cellular Context ◽  
Cellular Components

Glioblastoma multiforme (GBM) is the most common and aggressive type of primary brain tumor in adults, with a poor median survival of approximately 15 months after diagnosis. Despite several decades of intensive research on its cancer biology, treatment for GBM remains a challenge. Autophagy, a fundamental homeostatic mechanism, is responsible for degrading and recycling damaged or defective cellular components. It plays a paradoxical role in GBM by either promoting or suppressing tumor growth depending on the cellular context. A thorough understanding of autophagy’s pleiotropic roles is needed to develop potential therapeutic strategies for GBM. In this paper, we discussed molecular mechanisms and biphasic functions of autophagy in gliomagenesis. We also provided a summary of treatments for GBM, emphasizing the importance of autophagy as a promising molecular target for treating GBM.

scholarly journals Lactate dehydrogenase-A inhibition induces human glioblastoma multiforme stem cell differentiation and death

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Simona Daniele ◽  
Chiara Giacomelli ◽  
Elisa Zappelli ◽  
Carlotta Granchi ◽  
Maria Letizia Trincavelli ◽  
...  
Keyword(s):  
Stem Cell ◽  
Cell Differentiation ◽  
Lactate Dehydrogenase ◽  
Glioblastoma Multiforme ◽  
Stem Cell Differentiation ◽  
Human Glioblastoma ◽  
Human Glioblastoma Multiforme

Advances in the targeting of HIF-1α and future therapeutic strategies for glioblastoma multiforme

2016 ◽  
Vol 37 (2) ◽  
pp. 657-670 ◽  
Author(s):  
Gang Wang ◽  
Jun-Jie Wang ◽  
Xing-Li Fu ◽  
Rui Guang ◽  
Shing-Shun Tony To
Keyword(s):  
Glioblastoma Multiforme ◽  
Therapeutic Strategies

scholarly journals Subunit composition of CP43-less photosystem II complexes of Synechocystis sp. PCC 6803: implications for the assembly and repair of photosystem II

2012 ◽  
Vol 367 (1608) ◽  
pp. 3444-3454 ◽  
Author(s):  
M. Boehm ◽  
J. Yu ◽  
V. Reisinger ◽  
M. Beckova ◽  
L. A. Eichacker ◽  
...  
Keyword(s):  
Photosystem Ii ◽  
Gel Electrophoresis ◽  
Photochemical Activity ◽  
Subunit Composition ◽  
Null Mutant ◽  
Trap Potential ◽  
Native Gel ◽  
Oxygen Evolving ◽  
Pcc 6803

Photosystem II (PSII) mutants are useful experimental tools to trap potential intermediates involved in the assembly of the oxygen-evolving PSII complex. Here, we focus on the subunit composition of the RC47 assembly complex that accumulates in a psbC null mutant of the cyanobacterium Synechocystis sp. PCC 6803 unable to make the CP43 apopolypeptide. By using native gel electrophoresis, we showed that RC47 is heterogeneous and mainly found as a monomer of 220 kDa. RC47 complexes co-purify with small Cab-like proteins (ScpC and/or ScpD) and with Psb28 and its homologue Psb28-2. Analysis of isolated His-tagged RC47 indicated the presence of D1, D2, the CP47 apopolypeptide, plus nine of the 13 low-molecular-mass (LMM) subunits found in the PSII holoenzyme, including PsbL, PsbM and PsbT, which lie at the interface between the two momomers in the dimeric holoenzyme. Not detected were the LMM subunits (PsbK, PsbZ, Psb30 and PsbJ) located in the vicinity of CP43 in the holoenzyme. The photochemical activity of isolated RC47-His complexes, including the rate of reduction of P680 + , was similar to that of PSII complexes lacking the Mn 4 CaO 5 cluster. The implications of our results for the assembly and repair of PSII in vivo are discussed.

scholarly journals Analysis of Polymerase II Elongation Complexes by Native Gel Electrophoresis

2004 ◽  
Vol 279 (22) ◽  
pp. 23223-23228 ◽  
Author(s):  
Zhiqiang Zhang ◽  
Chwen-Huey Wu ◽  
David S. Gilmour
Keyword(s):  
Gel Electrophoresis ◽  
Native Gel
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