Role of MRP-1 and GST-Pi in MDR and their inhibition by indomethacin in AML

Peer review under responsibility of Alexandria University Faculty of Medicine.

Available online 16 August 2016

Figures & data

Table

MRP-1	F-5′-GGTCACGCACAGCATG and
	R-5′-GTACACGGAAAGCTTGAC produce a 417 bp fragment,
GST-Pi	F-5′-GGCTCACTAAAAGCCTCCTG and
	R-5′-CTACTGATACACTTCCGTGA produce a 244 bp fragment,
β-actin	(house-keeping gene): F-5′-GCACCACACCTTCTACAATGA and
	R-5′-GTCATCTTCTCGCGGTTGGC produce a 100 bp fragment.

Figure 1 Gel electrophoresis of PCR products. Lanes 1–4 show the 417 bp band of MRP-1, while lanes 5–8 show the 244 bp band of GST-Pi and the 100 bp band of β-actin.

Table 1 Mean ± standard error (M ± SE) of all hematological parameters in control group, AML patients, complete remission group and UR group.

Parameter		WBCs count (×10^9/L)	Blast cells (%)	Platelets count (×10^9/L)	RBCs count (×10^6/L)	Hb conc. (g/dL)
Controls (n = 20)		5.59 ± 0.33	0.0 ± 0.0	250.3 ± 11.3	4.38 ± 0.11	12.02 ± 0.27
AML patients (n = 50)		32.15 ± 6.29	55.20 ± 5.20	107.6 ± 17.1	2.98 ± 0.16	8.57 ± 0.45
CR group (n = 20)	At presentation	33.44 ± 12.12	62.6 ± 7.7	129.1 ± 33.0	3.01 ± 0.25	8.74 ± 0.72
	After 1st cycle	4.6 ± 0.7^^	0.9 ± 0.48^^	118.7 ± 13.5^⁎	3.41 ± 0.22^⁎	9.68 ± 0.68^⁎
UR group (n = 20)	At presentation	23.03 ± 7.29	44.40 ± 7.44	108.7 ± 25.9	3.02 ± 0.24	8.76 ± 0.52
	At relapse	30.53 ± 11.69^⁎^,^θ	52.70 ± 9.75^⁎	85.1 ± 24.2^⁎	2.89 ± 0.21^⁎	8.36 ± 0.52^⁎
	After 2nd cycle + indomethacin	5.74 ± 2.19^θ	1.5 ± 1.5^#^,^θ	128.3 ± 24.1^⁎	3.25 ± 0.09^⁎	8.66 ± 0.37^⁎

Student’s t-test, significant when P < 0.05.

⁎ Significant when comparing with control group.

^ Significant when comparing mean values at presentation with corresponding values after 1st cycle of chemotherapy in CR group.

# Significant when comparing mean values after induction cycle and after 2nd cycle + indomethacin with corresponding values at presentation in UR group.

θ Significant when comparing mean values after 2nd cycle + indomethacin with corresponding mean values after induction cycle in UR group.

Table 2 Number and percent of AML patients with positive GST-Pi and MRP-1 expression and comparisons of groups and subgroups.

Parameter		GST-Pi expression		MRP-1 expression
		+ve/total	%	+ve/total	%
Controls (n = 20)		10/20	50	4/20	20
AML patients (n = 50)		25/50	50	6/50	12
CR group (n = 20)	At presentation	12/20	60	4/20	20
	After 1st cycle	6/20	30^^	2/20	10
			P2 = 0.020
UR group (n = 20)	At presentation	6/20	30	2/20	10
	At relapse	16/20	80^⁎^,^#^,^♦	2/20	10
			P1 = 0.016
			P3 = 0.000
			P5 = 0.000
	After 2nd cycle + indomethacin	4/20	20^⁎^,^θ	0/20	0
			P1 = 0.016
			P4 = 0.000

Cochran’s Q test, significant when P ⩽ 0.05.

⁎ P1: significant when comparing with control group.

^ P2: significant when comparing values at presentation with corresponding values after 1st cycle of chemotherapy in CR group.

# P3: significant when comparing values after induction cycle and after 2nd cycle + indomethacin with corresponding values at presentation in UR group.

θ P4: significant when comparing values after 2nd cycle + indomethacin with corresponding values after induction cycle in UR group.

♦ P5: significant when comparing values after the 1st cycle of chemotherapy in CR group with that after induction cycle in UR group.

Figure 2 The percent positivity of both GST-Pi and MRP-1 in CR and UR groups through all study points.

Figure 3 Disease free survival according to (a) GST-Pi and (b) MRP-1 expression and overall survival according to (c) GST-Pi and (d) MRP-1 expression in AML patients.

Figure 4 Overall survival according to chemotherapy with and without indomethacin in all patients with AML.

Table 3 Correlation of GST-Pi and MRP-1 with laboratory parameters in all studied groups.

			WBCs count	Blast cells %
GST-Pi	CR group (n = 20)	At presentation	r = 0.583, P = 0.038	r = 0.612, P = 0.030
	UR group (n = 20)	After induction cycle	r = 0.612, P = 0.030	r = 0.667, P = 0.018
		After 2nd cycle + indomethacin	r = 0.667, P = 0.018	r = 0.667, P = 0.018
MRP-1	CR group (n = 20)	At presentation	r = 0.612, P = 0.030

p: Statistical significance (correlation is significant at P ⩽ 0.05).

r: Pearson’s two-tailed correlation coefficient.