Pleiotrophin and N-syndecan promote perineural invasion and tumor progression in an orthotopic mouse model of pancreatic cancer

Table 1 Associations between expression of pleiotrophin and N-syndecan with anatomical factors in an orthotopic mouse model of pancreatic cancer n (%)

Factor	PTN positive cases	N-syndecan positive cases
Peritoneal dissemination
Negative (n = 14)	71.4 (10)	57.1 (8)
Positive (n = 22)	63.6 (14)	63.6 (14)
Histological grade
I (n = 4)	50.0 (2)	25.0 (1)
II (n = 19)	73.7 (14)	68.4 (13)
III (n = 13)	61.5 (8)	61.5 (8)
Tumor size
≤ 1 cm (n = 8)	50.0 (4)	25.0 (2)a
> 1 cm but ≤ 2 cm (n = 21)	61.9 (13)	66.7 (14)a
> 5 cm (n = 7)	100.0 (7)	85.7 (6)a
Bloody ascites
V ≤ 1 mL (n = 8)	37.5 (3)b	50.0 (4)
1 cm < V ≤ 2 mL (n = 22)	68.2 (15)b	59.1 (13)
V > 2 mL (n = 6)	100.0 (6)b	83.3 (5)
Liver metastases
Negative (n = 14)	35.7 (5)a	42.8 (6)
Positive (n = 22)	86.4 (19)a	72.7 (16)
Lymph node metastasis
Negative (n = 20)	50.0 (10)	50.0 (10)
Positive (n = 16)	87.5 (14)	75.0 (12)

^aP < 0.05,

^bP < 0.01. Little bloody ascites: V ≤ 1 mL; Medium bloody ascites: 1 cm < V ≤ 2 mL; Large bloody ascites: V > 2 mL. PTN: Pleiotrophin.

Table 2 Relationship between expression of pleiotrophin and N-syndecan

Protein	PTN expression		P value
	Positive	Negative
N-syndecan (+) (n = 22)	17	5	0.048
N-syndecan (-) (n = 14)	7	7

(-), negative; (+), positive. PTN: Pleiotrophin.

Table 3 Associations between pleiotrophin and N-syndecan protein expression and perineural invasion in pancreatic cancer

Protein	PIN			P value
	0	1	2
PTN (+) (n = 24)	3	10	11	0.019
PTN (-) (n = 12)	6	4	2
N-syndecan (+) (n = 22)	2	8	12	0.032
N-syndecan (-) (n = 14)	6	5	3

PNI was scored as follows: 0, PNI was difficult to find, with ≤ one occurrence per slide; 1, PNI was easy to find, with two to four occurrences per slide; and 2, PNI was easy to find, with more than four occurrences per slide or intraneural invasion. PNI: Perineural invasion; PTN : Pleiotrophin.