Plasma long noncoding RNAs PANDAR, FOXD2-AS1, and SMARCC2 as potential novel diagnostic biomarkers for gastric cancer

Figures & data

Table 1 General characteristics of gastric cancer patients compared with health controls

		Health controls	Gastric cancer	P-value
N (%)/Median (min,max)	N (%)/Median (min,max)
Gender
	Female	55 (51.9%)	27 (24.8%)	<0.001*
	Male	51 (48.1%)	82 (75.2%)
Age
	<65	80 (75.5%)	66 (60.6%)	0.02*
	≥65	26 (24.5%)	43 (39.4%)
CEA		2.45 (0.51,8.19)	3.08 (0.63,147.10)	<0.001*
AFP		2.84 (0.66,10.03)	2.74 (0.88,22.46)	0.42
CA125		9.57 (3.25,37.95)	11.85 (4.39,114.20)	0.11
CA153		9.05 (3.41,27.75)	7.76 (2.50,92.65)	0.03*
CA199		10.51 (0.00,47.01)	9.93 (1.18,770.50)	0.40

Notes: For variable including gender and age, Chi-square was used. For CEA, AFP, CA125, CA153, and CA199, which did not fit normal distribution, nonparametric statistical test was used. *P<0.05.

Figure 1 Expression levels of plasma lncRNAs PANDAR (A), FOXD2-AS1 (B), and SMARCC2 (C) in gastric cancer (GC) and healthy subjects (Normal) evaluated by real-time PCR. *When compared with healthy subjects, a P<0.05 was considered statistically significant.

Table 2 Correlation between plasma lncRNAs and clinicopathological parameters of gastric cancer (n=109)

Features	Number of cases	plasma PANDAR levels(-ΔCt)	P-value	plasma FOXD2-AS1 levels(-ΔCt)	P-value	plasma SMARCC2 levels(-ΔCt)	P-value
Age (years)
<65	66	−0.51±0.21	0.054	−1.60±0.16	0.37	−1.37±0.15	0.20
≥65	43	−1.13±0.23		−1.82±0.18		−1.68±0.20
Gender
Male	82	−0.94±0.18	0.04*	−1.56±0.12	0.15	−1.56±0.14	0.33
Female	27	−0.19±0.28		−1.98±0.32		−1.29±0.21
Tumor size (cm)
<5	63	−0.96±0.20	0.12	−1.88±0.16	0.053	−1.67±0.16	0.07
≥5	46	−0.46±0.24		−1.41±0.17		−1.25±0.17
Pathological differentiation
Well+Moderate	37	−1.28±0.24	0.02*	−2.14±0.24	0.006*	−1.90±0.22	0.01*
Poor	72	−0.48±0.20		−1.45±0.13		−1.28±0.13
Invasion depth
T1+ T2+ T3	50	−1.15±0.22	0.20	−1.93±0.20	0.054	−1.76±0.14	0.04*
T4	59	−0.42±0.22		−1.47±0.14		−1.27±0.18
Lymph nodes metastasis
Negative	35	−1.11±0.28	0.12	−2.15±0.24	0.007*	−1.94±0.19	0.008*
Positive	74	−0.58±0.19		−1.46±0.13		−1.28±0.14
TNM stage
I and II	44	−1.17±0.25	0.03*	−2.06±0.21	0.009*	−1.92±0.17	0.002*
III and IV	65	−0.47±0.20		−1.43±0.13		−1.20±0.15

Notes: A parametric comparison was performed using Student’s t-test, and a non-parametric comparison was conducted using the Mann–Whitney U test. Chi-square test was used to verify the differences of nominative variables between the two groups. *P<0.05.

Figure 2 The ROC curves of current biomarkers including CEA, CA153, AFP, CA125, and CA199. (A) The ROC curves of each current biomarker. The area under the curve (AUC) for CEA was 0.661. The AUC for CA153 was 0.589. The AUC for AFP was 0.536. The AUC for CA125 was 0.558. The AUC for CA199 was 0.533. (B) The ROC curve of combined CEA, CA153, AFP, CA125, and CA199. The AUC was 0.709, P<0.001.

Figure 3 The ROC curves of plasma lncRNAs PANDAR, FOXD2-AS1, and SMARCC2. (A) The ROC curves of each plasma lncRNA. The AUC for PANDAR was 0.767. The AUC for FOXD2-AS1 was 0.700. The AUC for SMARCC2 was 0.748. (B) The ROC curve of combined lncRNAs PANDAR, FOXD2-AS1, and SMARCC2. The AUC was 0.839, P<0.001.

Table 3 Multivariable analysis of risk factors for gastric cancer using logistic regression analysis

	Multivariable		95% CI
P-value	OR
Gender
Female vs male	0.001	0.219	0.090	0.532
Age
>65 years vs ≤65 years	0.358	1.496	0.633	3.537
CEA
	0.022	1.243	1.032	1.496
AFP
	0.807	0.980	0.836	1.150
CA125
	0.540	1.013	0.972	1.055
CA153
	0.074	0.941	0.881	1.006
CA199
	0.089	1.025	0.996	1.056
PANDAR
	<0.001	1.690	1.313	2.176
FOXD2-AS1
	0.029	1.358	1.032	1.787
SMARCC2
	<0.001	1.681	1.293	2.186

Table S1 Primers for lncRNAs

LncRNAs	Forward primer (5ʹ-3ʹ)	Reverse primer (5ʹ-3ʹ)	Product length (bp)	TM (ºC)
PANDAR	TCCCAACAAACAAGGGGTGG	GTGGCCAAAGGATCTGACGA	92	60
FOXD2-AS1	AAGCGATCAGCTCCCTTAGC	CAGACGCGTGGTGGTTATCT	184	60
SMARCC2	ACAGCAGAATGAACTCCGCT	GTCTGAGTGCTGCAGGTAGG	110	60