Proteomic analysis of gastric cancer and immunoblot validation of potential biomarkers

Table 1 Patient and tumor characteristics

Characteristics	n (%)
Sex
Male	19 (59.4)
Female	13 (40.6)
Lauren’s classification
Intestinal	20 (62.5)
Diffuse	11 (34.4)
Mixed	1 (3.1)
Location
Corpus	8 (25)
Antrum	7 (21.9)
Cardia/gastroesophageal border	10 (31.2)
Several parts	7 (21.9)
Grade
Well-differentiated	2 (6.2)
Moderately differentiated	12 (37.5)
Poorly differentiated	12 (37.5)
Undifferentiated	6 (18.8)
pT
pT1b	1 (3.1)
pT2a	5 (15.6)
pT2b	15 (46.9)
pT3	11 (34.4)
pN
pN0	8 (25)
pN1	16 (50)
pN2	6 (18.8)
pN3	2 (6.2)

Table 2 Results of mass spectrometry identification

Protein name	Gene name	Swiss-Prot ID	pI/MW	Frequency1	Fold2	P value	Coverage3	No. of pep.4
Down-regulated
Gastrokine-1 precursor	GKN1	Q9NS71	5.3/21.0	75% (9/12)	15.17	0.000	16%	6
15-hidroxyprostaglandin dehydrogenase isoform 1	HPGD	P15428	5.6/25.2	66% (8/12)	3.85	0.016	23%	5
Enoyl CoA hydratase, mitochondrial precursor	ECHS1	P30084	5.8/27.9	66% (8/12)	3.38	0.001	49%	15
39S ribosomal protein L12, mitochondrial precursor	MRPL12	P52815	5.1/20.6	58.3% (7/12)	10.95	0.016	16%	4
Acyl-CoA dehydrogenase	ACADS	P16219	6.1/39.9	58.3% (7/12)	4.94	0.005	12%	5
NADH dehydrogenase (ubiquinone) flavoprotein 2, mitochondrial precursor	NDUFV2	P19404	5.7/24.2	50% (6/12)	2.26	0.027	58%	16
Phenazine biosynthesis-like domain-containing protein isoform a	PBLD	P30039	6.1/31.8	50% (6/12)	3.60	0.007	25%	5
Plasma cell-induced resident endoplasmic reticulum protein	PACAP	Q8WU39	5.2/22.0	41.6% (5/12)	4.41	0.042	39%	5
ATP synthase subunit d, mitochondrial	ATP5H	O75947	5.2/20.5	41.6% (5/12)	2.40	0.012	26%	5
Glutathione S-transferase mu 3	GSTM3	P21266	5.3/26.3	33.3% (4/12)	3.35	0.042	29%	4
Transthyretin	TTR	P02766	5.4/16.4	25% (3/12)	2.74	0.027	53%	7
Up-regulated
Septin-2	SEPT2	Q15019	6.0/41.0	75% (9/12)	4.58	0.009	34%	7
Maspin	SERPINB5	P36952	5.6/40.2	58.3% (7/12)	4.99	0.007	14%	5
Phosphoglycerate kinase 1	PGK1	P00558	6.0/40.1	58.3% (7/12)	6.46	0.016	22%	6
Pyruvate kinase, muscle	PKM2	P14619	6.0/38.8	58.3% (7/12)	5.25	0.021	20%	8
Actin, cytoplasmic 1	ACTB	P60709	4.8/32.2	58.3% (7/12)	7.77	0.005	44%	12
Tumor necrosis factor receptor superfamily member 16 precursor	NGFR	P08138	5.2/35.5	50% (6/12)	3.94	0.002	17%	5
Heat shock 70 kDa protein 1A/1B	HSPA1	P08107	5.1/36.9	50% (6/12)	4.77	0.009	14%	8
Heterochromatin-like protein 1	CBX3	Q13185	5.2/22.0	50% (6/12)	4.12	0.027	19%	3
Ubiquitin-conjugating enzyme E2 N	UBE2N	P61088	5.7/16.4	41.6% (5/12)	4.94	0.001	40%	5
Transaldolase	TALDO1	P37837	5.9/38.5	41.6% (5/12)	3.12	0.003	18%	5
Cathepsin D precursor	CTSD	P07339	5.3/28.4	41.6% (5/12)	3.49	0.034	27%	11
Annexin A4	ANXA4	P09525	5.6/31.3	41.6% (5/12)	13.31	0.027	54%	26
Myotrophin	MTPN	P58546	5.1/13.5	41.6% (5/12)	2.45	0.000	22%	4
Enolase 1 variant	ENO1	P06733	5.5/42.6	41.6% (5/12)	3.95	0.034	19%	7
Nicotinamide N-methyltransferase	NNMT	P40261	5.4/28.5	41.6% (5/12)	4.24	0.000	9%	3
Eukaryotic translation initiation factor 2 subunit 1	EIF2S1	P05198	4.9/33.5	41.6% (5/12)	6.61	0.042	24%	8
Translationally-controlled tumor protein	TPT1	P13693	4.8/20.7	25% (3/12)	2.50	0.002	18%	4
Annexin A5	ANXA5	P08758	5.0/32.4	25% (3/12)	3.24	0.005	70%	25
Nucleoside diphosphate kinase A isoform a	NME1	P15531	5.7/19.0	25% (3/12)	3.11	0.016	33%	5

¹Frequency shows the number of patients where the protein was differentially expressed in two-dimensional gel electrophoresis analysis;

²Fold stands for the average fold change in the relative spot volume between non-tumor and tumor (downregulated) or tumor and non-tumor (upregulated) tissue;

³Coverage stands for the sequence coverage in mass spectrometry (MS) analysis;

⁴No. of pep. stands for the number of matched peptides in MS analysis. MW: Molecular weight.