Dexamethasone induces altered binding of regulatory factors to HLA class I enhancer sequence in MCF-7 breast tumour cell line

1998 ◽  
Vol 46 (4) ◽  
pp. 194-200 ◽  
Author(s):  
F. Rodriguez ◽  
Maximino Redondo ◽  
Francisco Ruiz-Cabello
Keyword(s):  
Cell Line ◽  
Tumour Cell ◽  
Hla Class I ◽  
Breast Tumour ◽  
Class I ◽  
Tumour Cell Line ◽  
Enhancer Sequence ◽  
Regulatory Factors ◽  
Breast Tumour Cell ◽  
Mcf 7

Identification and Quantification of Antigens Associated with HLA Class I Molecules on a Bladder Tumour Cell Line

2003 ◽  
Vol 70 (3) ◽  
pp. 154-160 ◽  
Author(s):  
Nasir Torabi-Pour ◽  
W. John W. Morrow ◽  
Roghieh Saffie ◽  
Prashant G. Gowda ◽  
D. Perrett ◽  
...  
Keyword(s):  
Cell Line ◽  
Tumour Cell ◽  
Bladder Tumour ◽  
Hla Class I ◽  
Class I ◽  
Tumour Cell Line ◽  
Hla Class I Molecules ◽  
Identification And Quantification

scholarly journals The differential processing of proenkephalin A in mouse and human breast tumour cell lines

1999 ◽  
Vol 161 (3) ◽  
pp. 475-484 ◽  
Author(s):  
BK Brar ◽  
PJ Lowry
Keyword(s):  
Cell Line ◽  
Cell Lines ◽  
Tumour Cell ◽  
Breast Tumour ◽  
Human Breast ◽  
Human Breast Tumour ◽  
Breast Tumour Cell ◽  
Cell Lysates ◽  
Human Breast Tumour Cell ◽  
Tumour Cell Lines

We have carried out an investigation into the processing of the enkephalin-like immunoreactivity reported in breast tissue using two human breast tumour cell lines and a mouse tumour cell line. A 46 kDa form of proenkephalin (PE) has been observed in the cell lysates of two human breast tumour cell lines (MCF-7, ZR-75-1) and the mouse androgen-responsive Shionogi breast carcinoma cell line (SC115). PE processing in the cell lysates of these cells was assessed by a specific met-enkephalin RIA. The basal levels of processed PE in the MCF-7, ZR-75-1 and SC115 cell lysates were 30, 30 and 76% respectively. The processing enzymes PC1 and PC2, which have been implicated in the differential processing of PE, were detected by immunoblot analysis in these cells. PC1 was found within the cell extracts of all three cell lines. PC2 was only observed in the SC115 cell line, which may account for the higher percentage of processed PE measured. The cDNA of PC2 has been transfected into ZR-75-1 cells and this was accompanied by an increase in the level of processed PE from 30 to 76%. These breast tumour cell lines may provide a useful insight into the function of enkephalin-containing peptides in breast cancer.

Tumour cell growth in culture: dependence on arginine

2004 ◽  
Vol 107 (4) ◽  
pp. 371-379 ◽  
Author(s):  
Giuseppe CASO ◽  
Margaret A. McNURLAN ◽  
Nelson D. McMILLAN ◽  
Oleg EREMIN ◽  
Peter J. GARLICK
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Tumour Cell ◽  
Urea Cycle ◽  
Breast Tumour ◽  
Cell Protein ◽  
Tumour Cell Line ◽  
Intracellular Enzyme ◽  
Polyamine Synthesis ◽  
Mcf 7

The amino acid arginine has been shown to affect the growth of several tumours, although the mechanisms of its action are not clear. In the present study, using a human breast tumour cell line (MCF-7), we investigated the arginine requirements of tumour cells for optimal protein synthesis and growth, and the metabolic pathway responsible for the arginine-dependent growth. The results showed that MCF-7 cells are highly dependent on arginine for growth and that the requirement for arginine is much higher than for an indispensable amino acid, leucine, indicating that arginine is needed for pathways other than protein synthesis. In arginine-free cultures, growth could be completely restored by the urea cycle intermediate citrulline. However, arginine could not be replaced by the urea cycle intermediate and the direct precursor for polyamine synthesis, ornithine, or by the polyamine putrescine, suggesting that the high dependence on arginine is not due to a requirement for polyamine synthesis. Moreover, inhibition of NOS [NO (nitric oxide) synthase] did not affect cell protein synthesis and growth, and the arginine analogue and substrate for NOS, homoarginine, could not replace arginine, implying that the conversion of arginine into NO is not involved in the growth-promoting effects of arginine. The major determinant for the high dependence of MCF-7 cells for arginine was found to be the irreversible conversion of this amino acid into ornithine by the intracellular enzyme arginase. The conversion into ornithine caused a progressive depletion of arginine from the culture medium, which ultimately inhibited cell protein synthesis and halted growth. Intracellular arginase activity may be the major factor determining the requirement for arginine of all cells in culture.

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