Abstract
In vitro culture of H9 human lymphoid cells in the presence of 5.0 μM dideoxycytidine (ddC), for about 40-45 days, selected cells (H9-ddC cells), which were resistant to the drug and cross-resistant to AZT (zidovudine) and 5-fluoro-2′-deoxyuridine (FdUR). The major mechanism of cross-resistance to AZT and FdUR in these cells was low cellular activity of thymidine kinase (TK). To explore molecular mechanisms of the reduced TK activity in H9-ddC cells, the mRNA expression of TK1 and TK2 and western blot analysis of TK1 protein were performed. RT-PCR analysis revealed that in H9-ddC cells the expression of both TK1 and TK2 mRNA was reduced to 27.1% and 79.4%, respectively. The reduced TK1 gene expression was confirmed by an absence of a detectable TK1 protein band in western blot of H9-ddC cells. These results demonstrate that long-term treatment of H9 cells in the presence of ddC down-regulated TK1 and TK2 gene expression and reduced the expression and activity of TK in the resistant cells.
| Original language | English |
|---|---|
| Pages (from-to) | 835-842 |
| Number of pages | 8 |
| Journal | Life Sciences |
| Volume | 74 |
| Issue number | 7 |
| DOIs | |
| State | Published - Jan 2 2004 |
| Externally published | Yes |
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Keywords
- Cross-resistance
- Deoxycytidine kinase
- Dideoxycytidine
- Gene down regulation
- Thymidine kinase 2
- Thymidine kinase1
ASJC Scopus subject areas
- Pharmacology
Cite this
2′, 3′-Dideoxycytidine represses thymidine kinases 1 and 2 expression in T-lymphoid cells. / Han, Tieran; Fernandez, Marilyn; Sarkar, Malancha; Agarwal, Ram P.
In: Life Sciences, Vol. 74, No. 7, 02.01.2004, p. 835-842.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - 2′, 3′-Dideoxycytidine represses thymidine kinases 1 and 2 expression in T-lymphoid cells
AU - Han, Tieran
AU - Fernandez, Marilyn
AU - Sarkar, Malancha
AU - Agarwal, Ram P.
PY - 2004/1/2
Y1 - 2004/1/2
N2 - In vitro culture of H9 human lymphoid cells in the presence of 5.0 μM dideoxycytidine (ddC), for about 40-45 days, selected cells (H9-ddC cells), which were resistant to the drug and cross-resistant to AZT (zidovudine) and 5-fluoro-2′-deoxyuridine (FdUR). The major mechanism of cross-resistance to AZT and FdUR in these cells was low cellular activity of thymidine kinase (TK). To explore molecular mechanisms of the reduced TK activity in H9-ddC cells, the mRNA expression of TK1 and TK2 and western blot analysis of TK1 protein were performed. RT-PCR analysis revealed that in H9-ddC cells the expression of both TK1 and TK2 mRNA was reduced to 27.1% and 79.4%, respectively. The reduced TK1 gene expression was confirmed by an absence of a detectable TK1 protein band in western blot of H9-ddC cells. These results demonstrate that long-term treatment of H9 cells in the presence of ddC down-regulated TK1 and TK2 gene expression and reduced the expression and activity of TK in the resistant cells.
AB - In vitro culture of H9 human lymphoid cells in the presence of 5.0 μM dideoxycytidine (ddC), for about 40-45 days, selected cells (H9-ddC cells), which were resistant to the drug and cross-resistant to AZT (zidovudine) and 5-fluoro-2′-deoxyuridine (FdUR). The major mechanism of cross-resistance to AZT and FdUR in these cells was low cellular activity of thymidine kinase (TK). To explore molecular mechanisms of the reduced TK activity in H9-ddC cells, the mRNA expression of TK1 and TK2 and western blot analysis of TK1 protein were performed. RT-PCR analysis revealed that in H9-ddC cells the expression of both TK1 and TK2 mRNA was reduced to 27.1% and 79.4%, respectively. The reduced TK1 gene expression was confirmed by an absence of a detectable TK1 protein band in western blot of H9-ddC cells. These results demonstrate that long-term treatment of H9 cells in the presence of ddC down-regulated TK1 and TK2 gene expression and reduced the expression and activity of TK in the resistant cells.
KW - Cross-resistance
KW - Deoxycytidine kinase
KW - Dideoxycytidine
KW - Gene down regulation
KW - Thymidine kinase 2
KW - Thymidine kinase1
UR - http://www.scopus.com/inward/record.url?scp=0344196764&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0344196764&partnerID=8YFLogxK
U2 - 10.1016/j.lfs.2003.07.023
DO - 10.1016/j.lfs.2003.07.023
M3 - Article
VL - 74
SP - 835
EP - 842
JO - Life Sciences
JF - Life Sciences
SN - 0024-3205
IS - 7
ER -