Comprehensive analysis of the potential role and prognostic value of sine oculis homeobox homolog family in colorectal cancer

Table 1 Expression levels of sine oculis homeobox homolog family members in human normal tissues

Organs	SIX1		SIX2		SIX3		SIX4		SIX5		SIX6
	RNA	Protein	RNA	Protein	RNA	Protein	RNA	Protein	RNA	Protein	RNA	Protein
Cerebral cortex	+	-	+	NE	++	NE	+	NE	+	+	-	-
Thyroid gland	+	-	+	NE	-	NE	+	NE	++	++	-	-
Lung	+	-	+	NE	-	NE	+	NE	+	-	-	-
Esophagus	+	-	+	NE	-	NE	+	NE	+	+	-	-
Stomach	+	-	+	NE	-	NE	+	NE	++	++	-	-
Colon/rectum	-	-	+	NE	-	NE	+	NE	+++	++	-	-
Liver	-	-	-	NE	-	NE	+	NE	++	++	-	-
Pancreas	+	+	+	NE	+	NE	+	NE	+++	+	-	-
Kidney	-	-	+	NE	+	NE	+	NE	++	++	-	-
Urinary bladder	+	+	+	NE	-	NE	+	NE	++	++	-	-
Testis	+	++	+	NE	+	NE	+	NE	+	++	+	-
Prostate	+	++	+	NE	-	NE	+	NE	+++	++	-	-
Ovary	+	-	+	NE	-	NE	+	NE	+++	-	-	-
Endometrium	-	-	+	NE	-	NE	+	NE	+++	++	-	-
Uterine cervix	+	+++	+	NE	+	NE	+	NE	+++	-	-	-
Breast	+	-	+	NE	+	NE	+	NE	++	++	-	-
Skin	-	-	+	NE	-	NE	+	NE	+	-	-	-
Lymph node	+	-	+	NE	+	NE	-	NE	+	-	-	-
Bone marrow	-	-	-	NE	-	NE	+	NE	+	-	-	-

-: Not detected; +: Low levels; ++: Medium levels; +++: High levels; NE: Not examined; SIX: Sine oculis homeobox homolog.

Table 2 Expression levels of sine oculis homeobox homolog family members in different types of malignant tumors

Organs	SIX1		SIX2		SIX3		SIX4		SIX5		SIX6
	RNA	Protein	RNA	Protein	RNA	Protein	RNA	Protein	RNA	Protein	RNA	Protein
Cerebral cortex	-	-	-	NE	-	NE	-	-	-	-	-	-
Thyroid gland	+	-	+	NE	+	NE	+	+++	+	+++	+	-
Lung	+	+	+	NE	+	NE	+	+	+	+	+	-
Esophagus	-	-	-	NE	-	NE	-	-		-	-	-
Stomach	-	-	+	NE	+	NE	+	-	+	+	+	-
Colon/rectum	+	-	+	NE	+	NE	+	++	+	++	+	-
Liver	+	-	+	NE	+	NE	+	++	+	++	+	-
Pancreas	+	+	+	NE	+	NE	+	+	+	++	+	-
Kidney	+	-	+	NE	+	NE	+	+	+	+	+	-
Urinary bladder	+	-	+	NE	+	NE	+	+	+	+	+	-
Testis	+	-	+	NE	+	NE	+	+	+	+	+	-
Prostate	+	++	+	NE	+	NE	+	++	+	+++	+	-
Ovary	+	-	+	NE	+	NE	+	+	+	+++	+	+
Endometrium	+	+	+	NE	+	NE	+	+	+	++	+	-
Cervix uterine	+	++	+	NE	+	NE	+	++	+	+	+	-
Breast	+	++	+	NE	+	NE	+	+++	+	+++	+	-
Skin	-	-	-	NE	-	NE	-	+++	-	-	-	-
Lymph node	-	-	-	NE	-	NE	-	+	-	-	-	-
Bone marrow	-	-	-	NE	-	NE	-	-	-	-	-

-: Not detected; +: Low levels; ++: Medium levels; +++: High levels; NE: Not examined; SIX: Sine oculis homeobox homolog.

Table 3 The etiological and demographic information of colorectal cancer patients

Characteristic
Patients, n (M/F)	93 (44/49)
Type of tumor (colon tumor/others)	93 (93/0)
age in yr, mean ± SD (range)	67.7 ± 9.8 (43-90)
Histologic type, n (carcinoma/adjacent)	93 (93/87)
Pathological stage, n (I/II/III)	93 (1/77/15)
Primary tumor, n (T1/T2/T3/T4)1	92 (1/4/70/15)
Lymph node status, n (N0/N1/N2)	93 (58/26/9)
Survival state, n (life/death)	93 (48/45)

¹One patient with an undetected primary tumor was excluded.

F: Female; M: Male; SD: Standard deviation.

Table 4 Expression of sine oculis homeobox homolog 4 in colorectal cancer tissues and paired adjacent tissue

Tissue type	n	Low (%)	High (%)	χ2	P value
Adjacent tissues	87	60 (69.0)	27 (31.0)	22.10	< 0.0001
CRC tissues	87	29 (33.3)	58 (66.7)

CRC: Colorectal cancer.

Table 5 Relationship between the expression of sine oculis homeobox homolog 4 and clinicopathological parameters of colon cancer patients

Clinicopathological parameter	n	SIX4 expression		χ2	P value
		Low	High
Age
≤ 60 yr	22	10 (45.5%)	12 (54.5%)	1.558	0.2120
> 60 yr	71	22 (31.0%)	49 (69.0%)
Sex
Male	44	17 (38.6%)	27 (61.4%)	0.6614	0.4161
Female	49	15 (30.6%)	34 (69.4%)
Maximum tumor diameter1
< 5 cm	37	13 (35.1%)	24 (64.9%)	0.0034	0.9563
≥ 5 cm	55	19 (34.5%)	36 (65.5%)
Pathological stage
I-II	78	29 (37.2%)	49 (62.8%)	-	0.2470
III	15	3 (20.0%)	12 (80.0%)
Primary tumor
T1-T2	5	2 (40.0%)	3 (60.0%)	0.0696	0.9658
T3	70	24 (34.3%)	46 (65.7%)
T4	17	6 (35.3%)	11 (64.7%)
N
N0	58	24 (41.4%)	34 (58.6%)	3.318	0.0685
N1-N2	35	8 (22.9%)	27 (77.1%)

¹One patient with an undetected primary tumor was excluded.

SIX: Sine oculis homeobox homolog.