scholarly journals Heterogeneity in the Rate of Benzo[a]pyrene Metabolism in Single Cells: Quantitation Using Flow Cytometry

1982 ◽  
Vol 2 (6) ◽  
pp. 625-632 ◽  
Author(s):  
Arthur G. Miller ◽  
James P. Whitlock
Keyword(s):  
Flow Cytometry ◽  
Enzyme Activity ◽  
Cell Line ◽  
Single Cells ◽  
Hepatoma Cells ◽  
Microsomal Enzyme ◽  
Clonal Population ◽  
Enzyme Inducer ◽  
Mouse Hepatoma ◽  
Low Activity

We describe a method for quantitating heterogeneity in the rate of benzo[a]pyrene metabolism in single cells by using flow cytometry. We have used the technique to study the response of Hepa-1c1c7 mouse hepatoma cells to the microsomal enzyme inducer 2,3,7,8-tetrachlorodibenzo-p-dioxin. Cells responded in a relatively homogeneous fashion at different times of induction with a maximally inducing concentration of the inducer. However, the induction response could be heterogeneous at a submaximal inducer concentration. We found even higher heterogeneity of enzyme activity among low-activity variants derived from the Hepa-1c1c7 cell line. When cells of either high or low activity were isolated from such a clonal population, propagated, and reanalyzed, they displayed average enzyme activity and heterogeneity identical to the parental cells; therefore, the heterogeneity represents transient, nonheritable differences between cells within the population.

Heterogeneity in the Rate of Benzo[ a ]pyrene Metabolism in Single Cells: Quantitation Using Flow Cytometry

1982 ◽  
Vol 2 (6) ◽  
pp. 625-632
Author(s):  
Arthur G. Miller ◽  
James P. Whitlock
Keyword(s):  
Flow Cytometry ◽  
Enzyme Activity ◽  
Cell Line ◽  
Single Cells ◽  
Hepatoma Cells ◽  
Microsomal Enzyme ◽  
Clonal Population ◽  
Enzyme Inducer ◽  
Mouse Hepatoma ◽  
Low Activity

We describe a method for quantitating heterogeneity in the rate of benzo[ a ]pyrene metabolism in single cells by using flow cytometry. We have used the technique to study the response of Hepa-1c1c7 mouse hepatoma cells to the microsomal enzyme inducer 2,3,7,8-tetrachlorodibenzo- p -dioxin. Cells responded in a relatively homogeneous fashion at different times of induction with a maximally inducing concentration of the inducer. However, the induction response could be heterogeneous at a submaximal inducer concentration. We found even higher heterogeneity of enzyme activity among low-activity variants derived from the Hepa-1c1c7 cell line. When cells of either high or low activity were isolated from such a clonal population, propagated, and reanalyzed, they displayed average enzyme activity and heterogeneity identical to the parental cells; therefore, the heterogeneity represents transient, nonheritable differences between cells within the population.

Stable Expression of MouseCyplaland HumanCYP1A2cDNAs Transfected into Mouse Hepatoma Cells Lacking Detectable P450 Enzyme Activity

1990 ◽  
Vol 9 (6) ◽  
pp. 425-436 ◽  
Author(s):  
ALVARO PUGA ◽  
BAISAKHI RAYCHAUDHURI ◽  
KALMAN SALATA ◽  
YOU-HUI ZHANG ◽  
DANIEL W. NEBERT
Keyword(s):  
Enzyme Activity ◽  
Hepatoma Cells ◽  
Stable Expression ◽  
Mouse Hepatoma ◽  
P450 Enzyme

Hepatocellular expression of glucose-6-phosphatase is unaltered during hepatic regeneration

1998 ◽  
Vol 275 (4) ◽  
pp. G717-G722 ◽  
Author(s):  
Wisam F. Zakko ◽  
Carl L. Berg ◽  
John L. Gollan ◽  
Richard M. Green
Keyword(s):  
Gene Expression ◽  
Enzyme Activity ◽  
Protein Expression ◽  
Partial Hepatectomy ◽  
Initial Phase ◽  
Physiological Function ◽  
Liver Homogenate ◽  
Hepatic Regeneration ◽  
Mrna Levels ◽  
Microsomal Enzyme

Gluconeogenesis and glycogenolysis are essential hepatic functions required for glucose homeostasis. During the initial phase of hepatic regeneration, the immediate-early genes (IEG) are rapidly expressed, and the IEG RL-1 encodes for glucose-6-phosphatase (G-6- Pase). G-6- Pase is a microsomal enzyme essential for gluconeogenesis and glycogenolysis. This study employs a partial-hepatectomy model to examine the expression and activity of G-6- Pase. After partial hepatectomy, rat hepatic G-6- Pase gene expression is transcriptionally regulated, and mRNA levels are increased ≈30-fold. However, in contrast to this rapid gene induction, microsomal enzyme activity is unchanged after partial hepatectomy. Western blotting demonstrates that microsomal G-6- Pase protein expression is also unchanged after partial hepatectomy, and similar results are also noted in whole liver homogenate. Thus, despite marked induction in gene expression of the IEG G-6- Pase after partial hepatectomy, protein expression and enzyme activity remain unchanged. These data indicate that, although this hepatocyte IEG is transcriptionally regulated, the physiologically important level of regulation is posttranscriptional. This highlights the importance of correlating gene expression of IEG with protein expression and physiological function.

scholarly journals Substance P Antagonism as a Novel Therapeutic Option to Enhance Efficacy of Cisplatin in Triple Negative Breast Cancer and Protect PC12 Cells against Cisplatin-Induced Oxidative Stress and Apoptosis

Cancers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 3871
Author(s):  
Emma Rodriguez ◽  
Guangsheng Pei ◽  
Sang T. Kim ◽  
Alexis German ◽  
Prema Robinson
Keyword(s):  
Breast Cancer ◽  
Flow Cytometry ◽  
Cell Line ◽  
Pc12 Cells ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Therapeutic Option ◽  
Neuronal Cell ◽  
Receptor Antagonism ◽  
Tnbc Cell

Although cisplatin is very effective as a treatment strategy in triple-negative breast cancer (TNBC), it has unwarranted outcomes owing to recurrence, chemoresistance and neurotoxicity. There is critically important to find new, effective and safe therapeutics for TNBC. We determined if SP-receptor antagonism in combination with cisplatin may serve as a novel, more efficacious and safer therapeutic option than existing therapies for TNBC. We used a neuronal cell line (PC12) and two TNBC cell lines (Sum 185 and Sum 159) for these studies. We determined that the levels of cells expressing the high-affinity SP-receptor (neurokinin 1 receptor (NK1R)), as determined by flow-cytometry was significantly elevated in response to cisplatin in all three cells. We determined that treatment with aprepitant, an SP-receptor antagonist decreased cisplatin-induced, loss of viability (studied by MTT assay), production of reactive oxygen species (by DCFDA assay) and apoptosis (by flow-cytometry) in PC12 cells while it was increased in the two TNBC cells. Furthermore, we demonstrated that important genes associated with metastases, inflammation, chemoresistance and cell cycle progression are attenuated by SP-receptor antagonism in the TNBC cell line, Sum 185. These studies implicate that SP-receptor antagonism in combination with cisplatin may possibly serve as a novel, more efficacious and safer therapeutic option than existing therapies for TNBC.

Phenobarbital inhibits calpain activity and expression in mouse hepatoma cells

2016 ◽  
Vol 397 (1) ◽  
pp. 91-96 ◽  
Author(s):  
Nicola Groll ◽  
Ferdinand Kollotzek ◽  
Jens Goepfert ◽  
Thomas O. Joos ◽  
Michael Schwarz ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Transcriptional Regulation ◽  
Antiepileptic Drug ◽  
Signaling Pathway ◽  
Constitutive Androstane Receptor ◽  
Hepatoma Cells ◽  
Liver Cells ◽  
Mrna Levels ◽  
Calpain Activity ◽  
Mouse Hepatoma

Abstract The antiepileptic drug phenobarbital (PB) exerts hepatic effects related to cell proliferation and tumorigenesis which are closely linked to the Wnt/β-catenin signaling pathway. This pathway is, amongst others, regulated by calpain proteases. We now identified PB as an inhibitor of Wnt/β-catenin signaling in mouse hepatoma cells. Further analyses revealed that PB inhibits calpain activity, an effect which is at least in parts mediated by a transcriptional regulation of calpain mRNA levels and which is furthermore independent of the constitutive androstane receptor, the known mediator of most effects of PB in liver cells.

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