Involvement of other uptake transporters (e.g., OATP2B1, OATP1A2, OAT2, and OAT7) and apical transporters (such as MATE1, MRP2, BCRP, and MDR1/3) could not be excluded.
Fromm, "Characterization of ursodeoxycholic and norursodeoxycholic acid as substrates of the hepatic uptake transporters OATP1B1, OATP1B3, OATP2B1 and NTCP," Basic & Clinical Pharmacology & Toxicology, vol.
Tirona et al., "Characterization of OATP1B3 and OATP2B1
transporter expression in the islet of the adult human pancreas," Histochemistry and Cell Biology, vol.
Funk, "Substrate-dependent drug-drug interactions between gemfibrozil, fluvastatin and other organic anion-transporting peptide (OATP) substrates on OATP1B1, OATP2B1
, and OATP1B3," Drug Metabolism & Disposition, vol.
Expression and localization of the uptake transporters OATP2B1
, OATP3A1 and OATP5A1 in non-malignant and malignant breast tissue.
We compared these methods using four hepatic drug transporter proteins, that is, organic anion transporter polypeptide (OaTp) 1B1, OATP1B3, OATP2B1
, and P-glycoprotein (P-gp).
OATP Signature sequence OATP1A2 D T R W V G A OATP1B1 D S R [W.bar] V G A OATP1B3 D S R W V G A OATP1C1 D P Q W V G A OATP2A1 D P R W I G A OATP2B1
D P R W V G A OATP3A1 D P R W I G A OATP4A1 S P L W V G A OATP4C1 D P R W L G A OATP5A1 D P R F I G N OATP6A1 S P E W L W T OATP Signature sequence OATP1A2 W W F G F L OATP1B1 [W.bar] [W.bar] L [N.bar] F L OATP1B3 W W L G F L OATP1C1 W W L G Y L OATP2A1 W W L G L L OATP2B1
W W L G F L OATP3A1 W W G G F L OATP4A1 W W V G F L OATP4C1 W W I G F L OATP5A1 W W S G F L OATP6A1 W W I N F L
Previous in vitro studies showed that green tea catechins such as EGCG inhibited the activities of OATP1A2 and OATP2B1
which are expressed in the apical side of the intestinal epithelium in human (Roth et al.
We found significantly higher expression of OATP3A1, low expression of OATP1B3 and OATP2B1
, and similar expression of OATP4A1 and OATP5A1 in liver cancer patient samples compared to levels in normal tissue samples (Figure 6(c)).
The OATP2 family comprises two members, OATP2A1 and OATP2B1
. OATP2A1 was originally identified as the prostaglandin transporter (PGT).
Within this concept, transporters from the OATP (SLC21) family such as OATp1A2, OATP1B3, OATP2B1
, and OATP3A1 contribute to the cellular accumulation of E1S [11, 12], while ABC-efflux pumps from the MRP-family (ABCC1 and ABCC2), and the breast-cancer resistance protein (BCRP, ABCG2) mediates the efflux of E1S from the cells  ( Figure 2).
(SLC[O.sub.2]B1) expressed at the sinusoidal membrane of