Ectopic Expression of DAN Enhances the Retinoic Acid-Induced Neuronal Differentiation in Human Neuroblastoma Cell Lines

1998 ◽  
Vol 243 (3) ◽  
pp. 722-726 ◽  
Author(s):  
Yohko Nakamura ◽  
Toshinori Ozaki ◽  
Shingo Ichimiya ◽  
Akira Nakagawara ◽  
Shigeru Sakiyama
1989 ◽  
Vol 9 (10) ◽  
pp. 4337-4344
Author(s):  
S E Bates ◽  
L A Mickley ◽  
Y N Chen ◽  
N Richert ◽  
J Rudick ◽  
...  

Expression of a multidrug resistance gene (mdr1) and its protein product, P-glycoprotein (Pgp), has been correlated with the onset of multidrug resistance in vitro in human cell lines selected for resistance to chemotherapeutic agents derived from natural products. Expression of this gene has also been observed in normal tissues and human tumors, including neuroblastoma. We therefore examined total RNA prepared from human neuroblastoma cell lines before and after differentiation with retinoic acid or sodium butyrate. An increase in the level of mdr1 mRNA was observed after retinoic acid treatment of four neuroblastoma cell lines, including the SK-N-SH cell line. Western blot (immunoblot) analysis demonstrated concomitant increases in Pgp. However, studies of 3H-vinblastine uptake failed to show a concomitant Pgp-mediated decrease in cytotoxic drug accumulation. To provide evidence that Pgp was localized on the cell surface, an immunotoxin conjugate directed against Pgp was added to cells before and after treatment with retinoic acid. Incorporation of [3H]leucine was decreased by the immunotoxin in the retinoic acid-treated cells compared with the undifferentiated cells. These results demonstrate that whereas expression of the mdr1 gene can be modulated by differentiating agents, increased levels of expression are not necessarily associated with increased cytotoxic drug accumulation.


Peptides ◽  
1997 ◽  
Vol 18 (6) ◽  
pp. 835-841 ◽  
Author(s):  
James A Waschek ◽  
Vincent Lelievre ◽  
Dawn T Bravo ◽  
Thinh Nguyen ◽  
Jean-Marc Muller

1989 ◽  
Vol 9 (10) ◽  
pp. 4337-4344 ◽  
Author(s):  
S E Bates ◽  
L A Mickley ◽  
Y N Chen ◽  
N Richert ◽  
J Rudick ◽  
...  

Expression of a multidrug resistance gene (mdr1) and its protein product, P-glycoprotein (Pgp), has been correlated with the onset of multidrug resistance in vitro in human cell lines selected for resistance to chemotherapeutic agents derived from natural products. Expression of this gene has also been observed in normal tissues and human tumors, including neuroblastoma. We therefore examined total RNA prepared from human neuroblastoma cell lines before and after differentiation with retinoic acid or sodium butyrate. An increase in the level of mdr1 mRNA was observed after retinoic acid treatment of four neuroblastoma cell lines, including the SK-N-SH cell line. Western blot (immunoblot) analysis demonstrated concomitant increases in Pgp. However, studies of 3H-vinblastine uptake failed to show a concomitant Pgp-mediated decrease in cytotoxic drug accumulation. To provide evidence that Pgp was localized on the cell surface, an immunotoxin conjugate directed against Pgp was added to cells before and after treatment with retinoic acid. Incorporation of [3H]leucine was decreased by the immunotoxin in the retinoic acid-treated cells compared with the undifferentiated cells. These results demonstrate that whereas expression of the mdr1 gene can be modulated by differentiating agents, increased levels of expression are not necessarily associated with increased cytotoxic drug accumulation.


2014 ◽  
Vol 219 (3) ◽  
pp. S76-S77
Author(s):  
Alicia M. Waters ◽  
Jerry Stewart ◽  
Venkatram Atigadda ◽  
Donald Muccio ◽  
Clinton Grubbs ◽  
...  

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