Identification of functional promoter haplotypes of human concentrative nucleoside transporter 2, hCNT2 (SLC28A2).
The human concentrative nucleoside transporter 2 (hCNT2) plays a major role in the intestinal absorption of naturally occurring nucleosides as well as some nucleoside analog drugs. To determine if single nucleotide polymorphisms (SNPs) in the promoter region of hCNT2 affect gene expression, we examined approximately 1 kb upstream the hCNT2 transcription start site. Ninety Chinese samples were screened and seven SNPs were identified: -115T>G, -146T>A, -264A>G, -564G>A, -861A>C, -880T>C and -906C>T. Based on these seven variants and their relative positions, eight haplotypes were identified using PHASE v2.1.1. Three naturally occurring haplotypes were cloned into the pGL3-Basic vector and transfected into HEK293 cells. Dual luciferase assay revealed that haplotype 4 (GTAGACC) and 7 (GAGAACT) exhibited significantly lower expression levels compared to the published haplotype 1 (TTAGATC). Results from our in-vitro study showed that the hCNT2 promoter region haplotype may modulate gene expression and cause different drug responses.
Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
Linghui
L
Li
Seok Hwee
SH
Koo
Ivan Hee Kean
IH
Hong
Edmund Jon Deoon
EJ
Lee
D044466:Asian People / Q000235:genetics; D003001:Cloning, Molecular; D004252:DNA Mutational Analysis; D033721:Equilibrative Nucleoside Transporter 1 / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D014644:Genetic Variation; D006239:Haplotypes; D006801:Humans; D026901:Membrane Transport Proteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic / Q000235:genetics* / Q000502:physiology; D017422:Sequence Analysis, DNA; D014162:Transfection
D033721:Equilibrative Nucleoside Transporter 1; D026901:Membrane Transport Proteins; C065171:cif nucleoside transporter