FBLN4 as candidate gene associated with long-term and short-term survival with primary glioblastoma

Figures & data

Table 1 Independent glioma RNA expression microarray data sets

	Platform		Sample	LTS	STS
GSE16011	HU133 plus 2.0 arrays	GPL570	Frozen sample	6	14
GSE53733	HU133 plus 2.0 arrays	GPL570	Frozen sample	24	15
GSE13041	HG-U133A arrays	GPL96	Frozen sample	22	71
	HU133 plus 2.0 arrays	GPL570	Frozen sample	0	8
	Human Genome	GPL8300	Frozen sample	6	27
	U95Av2 array

Notes: LTS: n=58; STS: n=135.

Abbreviations: LTS, long-term survivor; STS, short-term survivor.

Table 2 Clinical characteristics of GBM patients

Characteristics	LTS (n=15)		STS (n=62)		P-value
	Number of samples	%	Number of samples	%
Age at diagnosis (years)					<0.01
Median (years)	49		56
Range (years)	21–76		17–81
>50	7	46.7	45	72.6
≤50	8	53.3	17	27.4
Gender					>0.05
Male	9	60.0	36	58.1
Female	6	40.0	26	41.9
KPS value					>0.05
90–100	9	60.0	40	64.5
70–89	4	26.7	15	24.2
<70	2	13.3	7	11.3
Extent of resection					>0.05
Gross	12	80.0	47	75.8
Subtotal	3	20.0	15	24.2
Radiation therapy					>0.05
No	2	13.3	10	16.1
Yes	13	86.7	52	83.9
Chemotherapy					>0.05
No	1	6.7	3	4.8
Yes	14	93.3	59	95.2
MGMT methylation					<0.01
Methylated	11	73.3	24	38.7
Unmethylated	4	26.7	38	61.3

Notes: Multivariate analysis on prognosis of the patients; n=59.

Abbreviations: GBM, glioblastoma multiforme; KPS, Karnofsky performance score; LTS, long-term survivor; STS, short-term survivor.

Figure 1 Distribution of (A) LTS and (B) STS status in the data from the 3 microarray data sets among the 4 subtypes of GBM.

Notes: LTS: n=58; STS: n=135.
Abbreviations: GBM, glioblastoma multiforme; LTS, long-term survivor; STS, short-term survivor.

Table 3 Classification of the 3 microarray data sets into the 4 subtypes of GBM

GBM subtype	GSE16011		GSE53733		GSE13041		Total
	LTS	STS	LTS	STS	LTS	STS	LTS	STS
Classical	1	5	12	12	21	82	34	99
Mesenchymal	0	5	0	1	3	10	3	16
Neural	1	0	1	0	1	6	3	6
Proneural	4	4	11	2	3	8	18	14
Total	6	14	24	15	28	106	58	135

Abbreviations: GBM, glioblastoma multiforme; LTS, long-term survivor; STS, short-term survivor.

Table 4 Comparison of mRNA expression of FBLN4, IGFBP-2, and CHI3L1 in tumor tissue by qRT-PCR and microarray analysis

Gene	Unique ID	Gene title	Gene origin	P-value
				LTS→normal	STS→normal	STS→LTS
FBLN4	206580_s_at	EGF-containing fibulin-like extracellular matrix protein 2	qRT-PCR Microarray	2.95E-02 4.68E-01	1.62E-03 6.83E-04	3.53E-03 1.01E-04
IGFBP-2	202718_at	Insulin-like growth factor binding protein 2	qRT-PCR Microarray	3.05E-02 1.08E-02	2.59E-03 8.28E-07	5.12E-03 2.40E-04
CHI3L1 (YKL-40)	209395_at	Chitinase 3-like 1	qRT-PCR Microarray	1.86E-02 4.14E-01	1.26E-02 3.87E-03	1.04E-02 3.18E-03

Notes: Significant values are shown in bold; P<0.01; P<0.05.

Abbreviations: GBM, glioblastoma multiforme; LTS, long-term survivor; qRT-PCR, quantitative reverse transcription polymerase chain reaction; STS, short-term survivor.

Table 5 Multivariate analysis on prognosis of the patients

Parameter	HR	95% CI	P-value
Gender	1.283	0.637–2.216	0.473
Age (>50), years	3.562	2.581–4.268	0.024
FBLN4	3.119	1.647–3.983	0.018
IGFBP-2	2.847	1.490–3.621	0.039
CHI3L1 (YKL-40)	2.051	2.409–5.277	0.052
MGMT methylation	3.781	2.195–5.263	0.009

Notes: LTS: n=15; STS: n=62. P<0.05.

Abbreviations: CI, confidence interval; HR, hazard ratio; LTS, long-term survivor; STS, short-term survivor.

Figure 2 Kaplan–Meier estimates of OS in relation to FBLN4 and IGFBP-2 expression as determined by qPCR.

Notes: Cutoff value for dichotomization of FBLN4 and IGFBP-2 expression and P-values were determined by maximally selected log-rank statistics. (A) High FBLN4 expression appeared to be strongly associated with poor OS in GBM patients; (B) IGFBP-2 expression appeared to be a strongly positive prognostic factor in GBM patients (P<0.01).
Abbreviations: GBM, glioblastoma multiforme; OS, overall survival; qPCR, quantitative polymerase chain reaction.