Upregulation of microRNA-100 predicts poor prognosis in patients with pediatric acute myeloid leukemia

Figures & data

Table 1 Characteristics of the 106 patients with pediatric acute myeloid leukemia

Clinical variables	Patients (n, %)	MiR-100 expression (n, %)		P
		Low	High
Sex
Male	58 (54.7)	23 (39.7)	35 (60.3)	0.6
Female	48 (45.3)	15 (31.3)	35 (68.7)
Age (years)
>6	40 (37.7)	10 (25.0)	30 (75.0)	0.2
≤6	66 (62.3)	26 (39.4)	40 (60.6)
Leukocytes (/μL)
>10,000	66 (62.3)	22 (33.3)	44 (66.7)	0.6
≤10,000	40 (37.7)	14 (35.0)	26 (65.0)
FAB classification
M1–M6	96 (90.6)	35 (36.5)	61 (63.5)	0.001
M7	10 (9.4)	1 (10.0)	9 (90.0)
Extramedullary disease
Absent	80 (75.5)	31 (38.8)	49 (61.2)	0.008
Present	26 (24.5)	5 (19.2)	21 (80.8)
Cytogenetics^*
Favorable	35 (33.0)	20 (20.0)	15 (80.0)	0.3
Intermediate	52 (49.1)	9 (17.3)	43 (82.7)
Unfavorable	19 (17.9)	7 (36.8)	12 (63.2)
Day 7 response to treatment
Favorable	65 (61.3)	26 (40.0)	39 (60.0)	0.01
Unfavorable	41 (38.7)	10 (23.3)	31 (76.7)

Notes:

* All patients were divided into three cytogenetic risk groups: favorable (inv[16], t[16;16], t[9;11], t[8;21]) (2,17); intermediate (normal cytogenetics or not classifiable as favorable or unfavorable); and unfavorable (−7, −5, del [5q], abnormal 3q, or complex karyotype) (2,17).

Abbreviations: MiR-100, microRNA-100; FAB, French–American–British.

Figure 1 MicroRNA-100 (miR-100) expression in 106 pediatric acute myeloid leukemia (AML) patients and normal controls.

Notes: After normalization to RNU6B expression levels, the expression level of miR-100 in the bone marrow of 106 pediatric AML patients (mean ± standard deviation [SD]: 10.8 ± 1.9) was significantly higher than that of normal controls (mean ± SD: 2.6 ± 0.7, P < 0.001). P-values were calculated using the Mann–Whitney U test.

Figure 2 Kaplan–Meier curves of relapse-free survival (A) and overall survival (B) of pediatric patients with newly diagnosed acute myeloid leukemia (AML) stratified by the level of microRNA-100 (miR-100) expression.

Notes: High miR-100 expression was associated with shorter relapse-free (P = 0.008) and overall (P = 0.006) survival in pediatric AML patients.

Table 2 Univariate analysis of the impact of variables on relapse-free and overall survival in pediatric acute myeloid leukemia patients

Variable	Patients (n)	Relapse-free survival		Overall survival
		Median (months ± SD)	P	Median (months ± SD)	P
Cytogenetics
Favorable	35	Not reached	<0.001	Not reached	<0.001
Intermediate	52	12.6 ± 1.8		22.9 ± 2.1
Unfavorable	19	3.1 ± 0.5		9.8 ± 1.7
FAB classification
M1–M6	96	14.3 ± 2.2	0.01	36.2 ± 3.8	0.008
M7	10	7.9 ± 1.4		20.7 ± 2.5
MiR-100 expression
Low (<10.8)	36	12.9 ± 1.6	0.008	37.4 ± 3.1	0.006
High (≥10.8)	70	5.8 ± 0.8		22.7 ± 2.9

Abbreviations: SD, standard deviation; FAB, French–American–British; MiR-100, microRNA-100.

Table 3 Multivariate analysis of the impact of variables on relapse-free survival and overall survival in pediatric acute myeloid leukemia patients

Variable	P	Odds ratio
Relapse-free survival
Cytogenetics
Unfavorable vs favorable/intermediate	0.01	5.9
FAB classification
M7 vs M1–M6	0.06	2.3
MiR-100 expression
High vs low	0.03	3.6
Overall survival
Cytogenetics
Unfavorable vs favorable/intermediate	0.009	7.1
FAB classification
M7 vs M1–M6	0.06	2.5
MiR-100 expression
High vs Low	0.01	5.2

Abbreviations: FAB, French–American–British; MiR-100, microRNA-100.