Deletion and downregulation of MTAP contribute to the motility of esophageal squamous carcinoma cells

Figures & data

Figure 1 MTAP deletion in ESCC analyzed by array-based comparative genomic hybridization.

Notes: The squares represent probes on the microarrays. The vertical ordinates represent the log₂ ratio of copy number changes of each probe.
Abbreviation: ESCC, esophageal squamous cell carcinoma.

Table 1 MTAP deletions in ESCC

Studies of ESCC genomic changes (number of cases)	Platform	Positive case
		Number	Frequency, %
Shi et al^Citation12 (n=59)	Array-CGH	23	39.0
Song et al^Citation9 (n=123)	Array-CGH	9	7.3
Sawada et al^Citation17 (n=40)	Array-CGH	5	12.5
Bass et al^Citation18 (n=29)	SNP array	6	20.7
The Cancer Genome Atlas	SNP array	22	24.4
Research Network^Citation19 (n=90)
Total (n=341)		64	19.1

Abbreviations: Array-CGH, array-based comparative genomic hybridization; ESCC, esophageal squamous cell carcinoma; SNP, single-nucleotide polymorphism.

Table 2 Relationship between MTAP deletion and clinicopathological parameters of ESCC patients

Parameters	Frequency, %	P-value
Gender		1.000a
Male	18.3 (46/251)
Female	19.0 (11/58)
Age		0.001a
<;60 years	10.9 (16/147)
≥60 years	25.3 (41/162)
pT		0.732a
T1 + T2	20.3 (15/74)
T3 + T4	18.0 (42/233)
LNM		0.558a
Negative	17.3 (28/162)
Positive	20.1 (29/144)
Grade		0.504b
G1	24.2 (8/33)
G2	34.2 (27/79)
G3	25.0 (7/28)

Notes:

a Mann–Whitney test.

b Kruskal–Wallis test.

Abbreviations: ESCC, esophageal squamous cell carcinoma; LNM, lymph node metastasis.

Figure 2 Decreased expression of MTAP mRNA and protein in ESCC.

Notes: (A) Distribution of log₂ ratio of MTAP copy number and mRNA expression in each case. (B) MTAP mRNA expression in primary ESCC tumors with and without MTAP deletions. (C) MTAP mRNA expression in esophageal epithelial cell lines and ESCC cell lines. (D) MTAP protein expression in primary ESCC tumors detected by Western blotting.
Abbreviations: ESCC, esophageal squamous cell carcinoma; N, esophageal epithelial cells from the paired surgical margins; T, tumors; RPKM, reads per kilobase per million mapped reads.

Table 3 Correlation of deletion and mRNA expression of MTAP in ESCC

Deletion	Downregulation of mRNA expression		Correlation	P-value
	Positive	Negative
Positive	20	2	0.826	1.17×10^−23
Negative	4	64

Abbreviation: ESCC, esophageal squamous cell carcinoma.

Figure 3 MTAP knockdown increased the motility of ESCC cells.

Notes: (A) MTAP protein expression in ESCC cell lines detected by Western blotting. (B) KYSE150 and KYSE450 cells were transfected with siMTAP or a nonsilencing siRNA. Transwell assays were carried out 24 hours after transfection of siRNA. (C) KYSE510 was transfected with pcDNA3.1 (control) or pcDNA3.1-MTAP. Transwell assays were carried out 24 hours after transfection of the plasmids. Representative images are shown. Scale bar: 50 μm. Magnification 100×.
Abbreviations: ESCC, esophageal squamous cell carcinoma; nonsilencing, nontargeting siRNA control; siMTAP, MTAP-specific siRNA; siRNA, small interfering RNA.

Figure 4 MTAP knockdown regulated the expression of proteins related with cell motility in ESCC.

Note: After MTAP knockdown in KYSE150 and KYSE450 cells, E-cadherin and p-GSK3β were downregulated, whereas Slug was upregulated.
Abbreviations: siMTAP, MTAP-specific siRNA; ESCC, esophageal squamous cell carcinoma.

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