TABLE 1

Generation of REFiP-gp and REFiBCRP from human jejunum and Caco-2 from relative mRNA expression and protein abundance (relative and absolute) data available in the literature for P-gp (MDR1) and BCRP

Transporter and MethodReference Standard Gene/Protein/PeptideJejunum Abundance Mean (S.D., Sample n)Caco-2 Abundance Mean (S.D., Sample n)REFSource
P-gp (MDR1)
 RT-PCRVillin7.90 (± 1.4, n = 13)11.0 (n = 1)0.7Taipalensuu et al., 2001a
 RT-PCRCyclophilin-A0.63 (± 0.23, n = 4)0.13 (n = 1)5.0Seithel et al., 2006b
 RT-PCRCyclophilin-A1.1 (± 0.67, n=5)0.21 (± 0.04, n=3 - 6)5.1Hilgendorf et al., 2007b
 Western blotNot run in blot2.12 (n = 1)1.04 (± 0.16, n = 3)2.0Troutman and Thakker, 2003bc
 Western blotNot run in blot1.00 (n = 5, pooled)1.29 (n = 2)0.8Von Richter et al., 2009c
 LC-MS/MSAGAVAEEVLAAIR1.89 (± 1.07, n = 3)4.67 (± 0.47, n = 3)0.4Harwood et al., 2016d
 LC-MS/MSFYDPLAGK0.77 (± 0.35, n = 3)2.08 (± 0.19, n = 3)0.4Harwood et al., 2016e
BCRP
 RT-PCRVillin2.7 (± 1.4, n = 13)0.03 (n = 1)90Taipalensuu et al., 2001a
 RT-PCRCyclophilin-A0.38 (± 0.08, n = 4)0.07 (n = 1)5.5Seithel et al., 2006b
 RT-PCRCyclophilin-A2.36 (± 0.29, n = 5)0.36 (n = 3 - 6)6.6Hilgendorf et al., 2007b
 Western blotNot run in blot1.00 (n = 5, pooled)0.84 (n = 2)1.2Von Richter et al., 2009c
 LC-MS/MSVIQELGLDK(2.56 ± 0.82, n = 3)(1.16 ± 0.04, n = 3)2.2Harwood et al., 2016d
 LC-MS/MSSSLLDVLAAR(2.06 ± 1.11, n = 3)(1.86 ± 0.14, n = 3)1.1Harwood et al., 2016e
  • RT-PCR, reverse-transcription polymerase chain reaction.

  • a Units for expression of mRNA are number of transcripts per microgram of total RNA.

  • b Units for expression given as relative units of target to reference gene (2-ΔCt).

  • c Values for expression given as signal intensity as measured by densitometry image analysis.

  • d Units for abundance given as fmol protein/µg total membrane protein; abundance determined at UoM. The same samples were quantified.

  • e Units for abundance given as fmol protein/µg total membrane protein; abundance determined at BPh. The same samples were quantified.