TABLE 3

Approximate number of mRNA copies per cell a in human hepatocytes and HepG2 cells


Gene

Human Hepatocytes (n = 4)

HepG2 (n = 4)

Ratio of Human Hepatocytes to HepG2
Mean
S.D.
Mean
S.D.
CYP1A1 40.14 16.39 2.93 0.93 13.71
CYP1A2 129.02 93.78 0.04 0.02 3657.56
CYP2B6 260.75 95.31 2.14 1.76 121.62
CYP2C9 495.53 101.12 0.10 0.03 5027.60
CYP2D6 30.13 19.72 0.94 0.47 32.07
CYP2E1 555.29 188.78 0.38 0.11 1464.42
CYP3A4 393.06 132.06 Not detectable
CYP3A7 0.84 0.59 0.66 0.73 1.26
EPHX1 101.00 52.10 42.83 28.38 2.36
GSTM1 96.58 44.93 8.23 3.26 11.73
UGT1A6 332.11 160.71 15.02 8.69 22.12
SULT1A1 37.24 13.92 122.33 18.28 0.30
NQO1 9.73 1.73 346.70 86.28 0.03
NAT1 9.14 5.16 10.91 3.04 0.84
GAPD b
3322.50
980.40
3947.49
1385.56
0.84
  • EPHX1, microsomal epoxide hydrolase; UGT, UDP-glucuronosyltransferase.

  • a Calculated on the basis that 40 pg of total RNA corresponds to one cell.

  • b For GAPD, data result from 45 and 40 probes from human hepatocytes and HepG2 samples, respectively, including treated and untreated samples.