Proteomic profiling of fetal esophageal epithelium, esophageal cancer, and tumor-adjacent esophageal epithelium and immunohistochemical characterization of a representative differential protein, PRX6

Table 1 Identification of differentially expressed proteins in tumor-adjacent normal esophageal epithelial tissue, esophageal squamous cell carcinoma tissue, and fetal esophageal tissue

Spot	Protein name and theoretical pI and Mr	Observed pI and Mr	No. of matched peptide fragments	Sequence coverage	MOWSE score
2	USP30 6.87/45546	9.3/32	2	4	21
4	Thyroid hormone receptor interactor 4.56/11 8489	7.8/31	3	56	51
5	Cardiac muscle 5.34/22563	6.25/29	5	24	66
6	Chain A, crystal structure of a recombinant glutathione transferase 5.09/23202	6.2/24	5	43	85
7	Dermatopontin precursor 4.7/23989	5.3/21.5	5	29	82
10	Heat shock protein 27 7.83/22313	7.1/20.5	5	29	79
11	S100 calcium-binding protein A9 5.71/13234	6.3/15	5	40	74
12	G-gamma-hemoglobin 6.17/11033	7.5/16	3	45	65
13	MB protein 9.24/10863	8.4/15.5	3	32	65
14	Immunoglobulin heavy chain variable region 9.78/13026	8.6/14	3	34	70
15	PREDICTED: hypothetical protein 5.27/6706	8.1/12	2	44	52
16	Immunoglobulin heavy chain variable region 9.04/13053	7.1/11	2	26	49
17	Heat shock 27kDa protein 1 5.98/22768	9.2/16	6	33	80
18	hCG1659706 10.28/5287	9.5/21	2	64	37
19	Smooth muscle protein 8.56/22461	9.4/19	6	26	86
21	hCG1997574 9.07/29453	7.3/32	7	31	93
22	Heat shock 27 kDa protein 1 5.98/22768	6.8/32	6	35	84
23	Disabled homolog 1 (Drosophila) 9.40/22903	7.15/31	6	26	66
24	Phosphoglycerate mutase 1 (brain), 6.40/24669	7.3/31	8	40	117
25	Peroxiredoxin 6 6.00/25019	7.1/27.8	8	41	116
26	Chain A, human triosephosphate isomerase of new crystal form 6.50/26666	7.3/30	10	38	160

Table 2 Expression of PRX6 protein in different types of esophageal lesions n (%)

Tissue	PRX6
	No. of cases	Negative	Positive
Tumor-adjacent
NOR	37	3 (8)	34 (92)
BCH	37	3 (8)	34 (92)
DYS	29	18 (62)	11 (38)
CIS	28	22 (79)	6 (21)
Esophageal cancer
W-SCC	7	0	7 (100)
M-SCC	16	3 (19)	13 (81)
P-SCC	6	5 (83)	1 (17)

P < 0.05, NOR vs DYS, CIS, M-SCC or P-SCC; BCH vs CIS, DYS, M-SCC or P-SCC; DYS vs W-SCC or M-SCC; CIS vs W-SCC or M-SCC; P-SCC vs W-SCC or M-SCC. NOR: Normal; BCH: Basal cell hyperplasia; DYS: Dysplasia; CIS: Carcinoma in situ; W-SCC: Well differentiated squamous cell carcinoma; M-SCC: Moderately differentiated; P-SCC: Poorly differentiated.

Table 3 Expression of PRX6 expression in esophageal tissues from fetuses of different gestational age n (%)

Age (mo)	PRX6
	No. of cases	Negative	Positive
3	6	0	6 (100)
4	4	0	4 (100)
5	6	1 (17)	5 (83)
6	6	0	6 (100)
7	5	1 (20)	4 (80)
8	6	1 (17)	5 (83)
9	6	2 (33)	4 (67)

P < 0.05, 3 mo vs 4 mo, 4 mo vs 7 mo, or 6 mo vs 7 mo.