Expression and predictive value of miR-489 and miR-21 in melanoma metastasis

Table 1 Primer sequences of miR-489, miR-21, and internal reference U6

Group	Forward primer	Reverse primer
miR-489	5'-ACACTCCAGCTGGGG TGACATCACATA-3'	5'-TGGTGTCGTGGAGTCG-3'
miR-21	5'-GCGGCGGTAGCTTATCAGACTG⁃3'	5'-ATCCAGTGCAGGGTCCGAGG⁃3'
U6	5'-CTCGCTTCGGCAGCACA-3'	5'-AACGCTTCACGAATTTGCGT-3'

Table 2 General clinical data of patients

Variable	Research group (n = 60)	Control group (n = 40)	t	P-value
Age (yr)			0.733	0.392
≤ 50	23 (38.33)	(30.00)
> 50	37 (61.67)	28 (70.00)
Gender			0.000	1.000
Male	30 (50.00)	20 (50.00)
Female	30 (50.00)	20 (50.00)
Tumor size (cm)
≤ 2	17 (28.33)	-	-	-
> 2	43 (71.67)	-	-	-
Lesion site
Non-acral	44 (73.33)	-	-	-
Acral	16 (26.67)	-	-	-
TNM stage
I	7 (11.67)	-	-	-
II	8 (13.33)	-	-	-
III	25 (41.67)	-	-	-
IV	20 (33.33)	-	-	-
Lymph node metastasis
Yes	45 (75.00)	-	-	-
No	15 (25.00)	-	-	-

Table 3 Relationship between expression of miR-489 and clinicopathological characteristics of melanoma

Variable	n	miR-489	t/F	P-value
Age (yr)			1.341	0.185
≤ 50	23	0.43 ± 0.26
> 50	37	0.51 ± 0.20
Gender			1.975	0.063
Male	30	0.54 ± 0.18
Female	30	0.42 ± 0.28
Tumor size (cm)			0.439	0.779
≤ 2	17	0.45 ± 0.30
> 2	43	0.39 ± 0.16
Lesion site			0.912	0.366
Non-acral	44	0.50 ± 0.22
Acral	16	0.44 ± 0.24
TNM stage			4.269	0.009
I	7	0.62 ± 0.29
II	8	0.48 ± 0.24
III	25	0.47 ± 0.22
IV	20	0.31 ± 0.17
Metastasis			5.622	< 0.001
Yes	45	0.30 ± 0.16
No	15	0.64 ± 0.30

Table 4 Relationship between clinicopathological characteristics of melanoma and miR-21 expression

Variable	n	miR-21	t/F	P-value
Age (yr)			1.984	0.052
≤ 50	23	4.72 ± 2.00
> 50	37	5.84 ± 2.20
Gender			0.582	0.563
Male	30	5.12 ± 1.75
Female	30	5.44 ± 2.45
Tumor size (cm)			0.386	0.873
≤ 2	17	4.99 ± 1.68
> 2	43	5.57 ± 2.52
Lesion site			0.386	0.873
Non-acral	44	5.16 ± 1.55
Acral	16	5.40 ± 2.65
TNM stage			5.040	0.004
I	7	3.60 ± 1.79
II	8	5.23 ± 2.13
III	25	5.28 ± 2.01
IV	20	7.01 ± 2.47
Metastasis			3.295	0.002
Yes	45	6.38 ± 2.35
No	15	4.18 ± 1.85

Table 5 Diagnostic value of serum miR-489 and miR-21 in patients before treatment

Index	miR-489	miR-21
AUC	0.852	0.844
95%CI	0.7678-0.9359	0.7633-0.9256
Std. Error	0.0429	0.0414
Cut-off value	0.451	4.841
Sensitivity (%)	75.56	77.78
Specificity (%)	80.00	82.22

Table 6 Assignment description of related factors of melanoma metastasis

Correlative factor	Assignment description
Age (yr)	< 50 = 0; ≥ 50 = 1
Gender	Male = 0; female = 1
Tumor size (cm)	≤ 2 = 0; > 2 = 1
Lesion site	Non-arcal = 0; arcal =1
TNM stage	I-II = 0; III-IV =1
miR-489	< 0.451 = 0; > 0.451 = 1
miR-21	< 4.841= 0; > 4.841 = 1

Table 7 Single-factor analysis of melanoma metastasis

Factor	Metastasis of melanoma (n = 45)	Melanoma is non-metastatic (n = 15)	t/X2	P-value
Age (yr)			6.792	0.009
≤ 50	13 (28.89)	10 (66.67)
> 50	32 (71.11)	5 (33.33)
Gender			2.222	0.136
Male	25 (55.56)	5 (33.33)
Female	20 (44.44)	10 (66.67)
Tumor size (cm)			14.470	< 0.001
≤ 2	7 (15.56)	10 (66.67)
> 2	38 (84.44)	5 (33.33)
Lesion site			0.000	1.000
Non-acral	33 (73.33)	11 (73.33)
Acral	12 (26.67)	4 (26.67)
TNM stage			35.920	< 0.001
I	0 (0.00)	7 (46.67)
II	3 (6.67)	5 (33.33)
III	22 (48.89)	3 (20.00)
IV	20 (44.44)	0 (0.00)
miR-489	0.64 ± 0.30	0.30 ± 0.16	4.179	< 0.001
miR-21	6.38 ± 2.35	4.18 ± 1.85	3.295	0.002

Table 8 Multivariate analysis of melanoma metastasis

Factor	β	SE	Wald	P	Exp (β)	95%CI
TNM stage	1.393	0.752	4.172	0.041	4.890	1.038-19.304
miR-489	1.385	1.625	0.762	0.529	3.146	0.182-34.021
mir-21	-2.037	1.232	6.514	0.038	0.391	0.059-1.449