PMID- 9358542
OWN - NLM
STAT- MEDLINE
DCOM- 19980122
LR  - 20190818
IS  - 0724-8741 (Print)
IS  - 0724-8741 (Linking)
VI  - 14
IP  - 10
DP  - 1997 Oct
TI  - Transient expression of a purine-selective nucleoside transporter (SPNTint) in a 
      human cell line (HeLa).
PG  - 1316-21
AB  - PURPOSE: The goal of this study was to develop a mammalian expression system for 
      the cloned rat intestinal, Na(+)-dependent, purine-selective nucleoside 
      transporter (SPNTint) and to study the interactions of nucleosides and nucleoside 
      analogs with this transporter. METHODS: Lipofection was used to transfect HeLa 
      cells with a mammalian expression vector (pcDNA3) containing the cDNA insert 
      encoding SPNTint. Nucleoside transport activity was measured using [3H]inosine, 
      [3H]uridine, [3H]-dideoxyinosine (ddI), and [3H]-2-chloro-2'-deoxyadenosine 
      (2CdA) as model substrates. RESULTS: Expression of SPNTint was observed between 
      36 and 90 h post-transfection, with maximal expression at 66 h. At 66 h, 
      Na(+)-stimulated uptake of [3H]inosine in cells transiently transfected with 
      SPNTint was approximately threefold greater than that in cells transfected with 
      empty vector (p < 0.05). The Na(+)-stimulated uptake of both inosine and uridine 
      was saturable (K(m) = 28.1 +/- 7.1 microM and 20.6 +/- 5.6 microM, respectively) 
      in the transfected cells and was significantly inhibited by the naturally 
      occurring nucleosides (1 mM) inosine and uridine and to a lesser extent by 
      thymidine. The nucleoside analogs ddI (IC50 = 46 microM) and 2CdA (IC50 = 13 
      microM) also significantly inhibited the Na(+)-stimulated uptake of [3H]inosine. 
      A Na(+)-stimulated uptake of [3H]2CdA was observed suggesting that 2CdA is also a 
      permeant of SPNTint. CONCLUSIONS: HeLa cells transiently transfected with SPNTint 
      represent a useful tool to study the kinetics and interactions of drugs with 
      SPNTint.
FAU - Schaner, M E
AU  - Schaner ME
AD  - Department of Biopharmaceutical Sciences, University of California San Francisco 
      94143, USA.
FAU - Wang, J
AU  - Wang J
FAU - Zevin, S
AU  - Zevin S
FAU - Gerstin, K M
AU  - Gerstin KM
FAU - Giacomini, K M
AU  - Giacomini KM
LA  - eng
GR  - GM42230/GM/NIGMS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Pharm Res
JT  - Pharmaceutical research
JID - 8406521
RN  - 0 (Carrier Proteins)
RN  - 0 (Membrane Transport Proteins)
RN  - 0 (Purine Nucleosides)
RN  - 0 (cif nucleoside transporter)
RN  - 47M74X9YT5 (Cladribine)
RN  - 5A614L51CT (Inosine)
RN  - 9NEZ333N27 (Sodium)
RN  - K3GDH6OH08 (Didanosine)
RN  - WHI7HQ7H85 (Uridine)
SB  - IM
MH  - Animals
MH  - Carrier Proteins/*biosynthesis/genetics/metabolism
MH  - Cladribine/metabolism
MH  - Didanosine/metabolism
MH  - HeLa Cells
MH  - Humans
MH  - Inosine/antagonists & inhibitors/metabolism
MH  - Kinetics
MH  - *Membrane Transport Proteins
MH  - Purine Nucleosides/*biosynthesis/genetics/metabolism
MH  - Rats
MH  - Sodium/pharmacology
MH  - *Transfection
MH  - Uridine/antagonists & inhibitors/metabolism
EDAT- 1997/11/14 00:00
MHDA- 1997/11/14 00:01
CRDT- 1997/11/14 00:00
PHST- 1997/11/14 00:00 [pubmed]
PHST- 1997/11/14 00:01 [medline]
PHST- 1997/11/14 00:00 [entrez]
AID - 10.1023/a:1012148016794 [doi]
PST - ppublish
SO  - Pharm Res. 1997 Oct;14(10):1316-21. doi: 10.1023/a:1012148016794.