scholarly journals Control and function of the transamination pathways of glutamine oxidation in tumour cells

1991 ◽  
Vol 273 (2) ◽  
pp. 271-275 ◽  
Author(s):  
Z Kovačević ◽  
O Brkljač ◽  
K Bajin
Keyword(s):  
Malic Enzyme ◽  
Hepatoma Cell ◽  
Ehrlich Ascites Carcinoma ◽  
Similar Rate ◽  
Hepatoma Cells ◽  
Metabolizing Enzymes ◽  
Cell Plasma ◽  
Ehrlich Ascites ◽  
And Function ◽  
Low Activity

Parallel investigations of the transamination pathways of glutamine oxidation in Ehrlich ascites carcinoma (EAC) and AS 30D hepatoma revealed that hepatoma cells, unlike EAC, produce very little aspartate. This cannot be explained by differences in the activity of glutamine-metabolizing enzymes. Also, the mitochondria from the hepatoma respired at a similar rate to EAC mitochondria with glutamine as sole substrate producing substantial amounts of aspartate. Unlike their isolated mitochondria, intact hepatoma cells showed a very low rate of glutamine oxidation. Compared with EAC, the rate of L-[U-14C]glutamine consumption by AS 30D hepatoma cells was much lower, with insignificant production of 14C-labelled aspartate and CO2. This suggested that the glutamine-transporting system in the hepatoma cell plasma membrane had a very low activity. Isolated hepatoma mitochondria produced 3 times more pyruvate from malate than did EAC mitochondria, indicating a higher activity of NAD(P)-dependent malic enzyme. We postulate that an active malic enzyme may suppress the synthesis of aspartate in hepatoma cells, but further evidence is needed to confirm this assumption.

scholarly journals Biosynthesis, surface expression and function of the fibronectin receptor after rat liver cell transformation to tumorigenicity

1993 ◽  
Vol 291 (1) ◽  
pp. 247-255 ◽  
Author(s):  
M Decastel ◽  
M A Doyennette-Moyne ◽  
E Gouet ◽  
M Aubery ◽  
P Codogno
Keyword(s):  
Molecular Mass ◽  
Hepatoma Cell ◽  
Rat Hepatocytes ◽  
Hepatoma Cells ◽  
Rat Hepatocyte ◽  
Fibronectin Receptor ◽  
Zajdela Hepatoma ◽  
Sds Page ◽  
Normal Rat ◽  
And Function

Zajdela hepatoma cells are poorly-adherent cells derived from an undifferentiated tumour and transplanted into rat. We compared the biosynthesis, structure and function of the fibronectin receptor in normal rat hepatocytes with that in Zajdela hepatoma cells. The rat hepatocyte fibronectin receptor has been isolated. It is composed of two subunits: alpha 5 (molecular mass 155 kDa) and beta 1 (molecular mass 115 kDa). However, its biosynthesis has not yet been described. Using polyclonal antibodies raised against each of the subunits of the receptor, we observed that the alpha 5-subunit was synthesized as a 155-kDa polypeptide in normal rat hepatocytes and Zajdela hepatoma cells. In contrast, the molecular mass of the beta 1-subunit was 130 kDa in Zajdela hepatoma cells versus 115 kDa in normal rat hepatocytes. Pulse-chase experiments showed that the apparent transition time from the 100-kDa beta 1-precursor to the 130-kDa mature form was abnormally prolonged in Zajdela hepatoma cells since the latter was not detected until 24 h, while the transition from the 100-kDa precursor to the 115-kDa mature form began within 3 h in normal rat hepatocytes. Digestion of both the normal rat hepatocytes and Zajdela hepatoma cells 100-kDa beta 1-precursors with endo-beta-N-acetylglucosaminidase H and peptide N-glycosidase yielded products from 100 kDa to 84 kDa and 82 kDa, respectively, as judged by SDS/PAGE, suggesting that the same polypeptide chain is synthesized in normal rat hepatocytes and in Zajdela hepatoma cells. Incubation of the mature normal rat hepatocyte beta 1-subunit with peptide N-glycosidase reduced its molecular mass from 115 kDa to 82 kDa, as judged by SDS/PAGE, while the molecular mass of the abnormal mature Zajdela hepatoma cell beta 1-subunit decreased from 130 to 110 kDa. Thus, in addition to alterations in the Asn-linked oligosaccharide processing, ‘ascitic growth’ induced other post-translational modifications in the Zajdela hepatoma cell beta 1-subunit. Furthermore, both the abnormal mature 130-kDa and precursor 100-kDa beta 1-subunits were detected on the surface of Zajdela hepatoma cells, associated with the alpha 5-subunit. The relationship between these structural alterations in the fibronectin receptor and the impaired Zajdela hepatoma cell binding to soluble fibronectin or to a coated fibronectin matrix that was observed in this study is discussed.

scholarly journals Mechanism and control of degradation and resynthesis of adenylates in tumour cells

1991 ◽  
Vol 273 (2) ◽  
pp. 277-281 ◽  
Author(s):  
Z Kovačević ◽  
O Brkljač ◽  
D Jeranče
Keyword(s):  
Adenine Nucleotide ◽  
Essential Feature ◽  
Ehrlich Ascites Carcinoma ◽  
Hepatoma Cells ◽  
Tumour Cells ◽  
Ehrlich Ascites ◽  
Purine Nucleotide Cycle ◽  
Adenine Nucleotide Pool ◽  
Energy Buffer ◽  
And Control

A comparative study revealed that Ehrlich ascites carcinoma (EAC) cells use glutamine plus inosine for regeneration of adenylates via the purine nucleotide cycle, whereas AS 30D hepatoma cells use adenosine instead. This observation can be correlated with the very low production of aspartate from glutamine in hepatoma cells. Although glucose is an important energy fuel for EAC, it cannot maintain a high enough level of adenylates unless glutamine is also present. Kinetic analysis of hydrolysis of ATP and ADP in the presence of rotenone suggests that deamination of AMP does not maintain a high enough ATP/ADP ratio and probably does not act as energy buffer after inhibition of cell respiration. It seems that, compared with normal cells, malignant cells have the ability for a very rapid regeneration of adenylates. It is proposed that instability of the adenine nucleotide pool, owing to frequent aerobic-anaerobic transitions, represents an essential feature of neoplasia, with profound impact on the whole metabolism of tumour cells.

Trichosanthes dioica seed lectin inhibits Ehrlich ascites carcinoma cells growth in vivo in mice by inducing G 0 /G 1 cell cycle arrest

2021 ◽  
Author(s):  
Shaikh Shohidul Islam ◽  
Md. Rezaul Karim ◽  
A. K. M. Asaduzzaman ◽  
A. H. M. Khurshid Alam ◽  
Zahid Hayat Mahmud ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Ehrlich Ascites Carcinoma ◽  
Carcinoma Cells ◽  
Cycle Arrest ◽  
Ehrlich Ascites ◽  
Trichosanthes Dioica

scholarly journals Expression of laminin γ 1 cultured hepatocytes involves repeated CTC and GC elements in the LAMC1 promoter

1996 ◽  
Vol 313 (3) ◽  
pp. 745-752 ◽  
Author(s):  
Françoise LEVAVASSEUR ◽  
Jocelyne LIÉTARD ◽  
Kohei OGAWA ◽  
Nathalie THÉRET ◽  
Peter D. BURBELO ◽  
...  
Keyword(s):  
Transcriptional Activation ◽  
Hepatoma Cell ◽  
Primary Cultures ◽  
Regulatory Elements ◽  
Hepatoma Cells ◽  
Basement Membranes ◽  
Major Protein ◽  
Cultured Hepatocytes

Laminin γ1 chain is present in all basement membranes and is expressed at high levels in various diseases, such as hepatic fibrosis. We have identified cis- and trans-acting elements involved in the regulation of this gene in normal rat liver, as well as in hepatocyte primary cultures and hepatoma cell lines. Northern-blot analyses showed that laminin γ1 mRNA was barely detectable in freshly isolated hepatocytes and expressed at high levels in hepatocyte primary cultures, as early as 4 h after liver dissociation. Actinomycin D and cycloheximide treatment in vivo and in vitro indicated that laminin γ1 overexpression in cultured hepatocytes was under the control of transcriptional mechanisms. Transfection of deletion mutants of the 5´ flanking region of murine LAMC1 gene in hepatoma cells that constitutively express laminin γ1 indicated that regulatory elements were located between -594 bp and -94 bp. This segment included GC- and CTC-containing motifs. Gel-shift analyses showed that two complexes were resolved with different affinity for the CTC sequence depending on the location of the GC box. The pattern of complex formation with nuclear factors from freshly isolated and cultured hepatocytes was different from that obtained with total liver and similar to that with hepatoma cells. Southwestern analysis indicated that several polypeptides bound the CTC-rich sequence. Affinity chromatography demonstrated that a Mr 60000 polypeptide was a major protein binding to the CTC motif. This polypeptide is probably involved in the transcriptional activation of various proto-oncogenes and extracellular matrix genes that are expressed at high levels in both hepatoma cells and early hepatocyte cultures.

Antioxidant, cytotoxic and apoptotic potentials of seeds of Momordica subangulata subsp. renigera inhibit the growth of Ehrlich ascites carcinoma in mice

2019 ◽  
Vol 13 (4) ◽  
pp. 3049-3059
Author(s):  
Polash Chandra Karmakar ◽  
Rumana Yesmin ◽  
Hanif Ali ◽  
M. Rowshanul Habib ◽  
Dhirendra Nath Barman ◽  
...  
Keyword(s):  
Ehrlich Ascites Carcinoma ◽  
Ehrlich Ascites
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