Low PLCE1 levels are correlated with poor prognosis in hepatocellular carcinoma

Figures & data

Figure 1 Real-time polymerase chain reaction analysis of PLCE1 expression in 20 pairs of hepatocellular carcinomas and matched adjacent nontumorous tissues.

Note: **P<0.01.
Abbreviations: mRNA, messenger RNA; PLCE1, phospholipase C epsilon-1.

Figure 2 Western blotting analysis of PLCE1 expression in tissues from HCC tumorous tissues or cell lines and adjacent nontumorous tissues or normal liver epithelial cells.

Notes: (A) Representative results of PLCE1 protein expression in paired HCC tumorous tissues (T) and the matched ANT from 3 patients. PLCE1-protein expression was normalized to β-actin. (B) All of the paired HCC tissues and the matched adjacent noncancerous tissues from 20 patients. *P<0.05. (C) PLCE1 protein expression in THLE3 and 4 cultured HCC cell lines. β-actin was used as internal control.
Abbreviations: ANT, adjacent nontumorous tissues; HCC, hepatocellular carcinoma; PLCE1, phospholipase C epsilon-1.

Figure 3 Representative immunohistochemical staining of PLCE1 in HCC and matched adjacent noncancerous liver tissues.

Notes: (A, D) Low expression of PLCE1 in HCC tissue cells. (B, E) Positive expression of PLCE1 in matched adjacent noncancerous tissue cells. (C, F) Low expression of PLCE1 in adjacent noncancerous tissue cells. (A–C) Magnification 100×; (D–F) Magnification 400×. Bar =50 μm.
Abbreviations: HCC, hepatocellular carcinoma; PLCE1, phospholipase C epsilon-1.

Table 1 Expression of PLCE1 in relation to clinicopathologic features

Variable	Total	PLCE1 expression		χ^2 test	P-value
		Positive	Negative
Age (years)				0.166	0.684
≤50	37	19	18
>50	53	35	18
Gender				2.937	0.087
Male	77	49	28
Female	13	5	8
Tumor capsular				5.030	0.025
Absent	42	20	22
Present	48	34	14
Tumor size (cm)				3.117	0.077
≤5	35	25	10
>5	55	29	26
Vascular invasion				7.500	0.006
No	30	24	6
Yes	60	30	30
Edmondson grade				6.750	0.009
I–II	50	36	14
III–IV	40	18	22
AFP (ng/mL)				6.433	0.011
≤20	53	26	27
>20	37	28	9
HBsAg				2.411	0.121
Negative	20	15	5
Positive	70	39	31
Cirrhosis				2.141	0.143
Absent	16	7	9
Present	74	47	27
Child–Pugh grade				0.010	0.921
A	67	40	27
B	23	14	9
TNM stage				6.750	0.009
I–II	58	36	14
III–IV	32	18	22
Tumor nodule				0.100	0.752
1	71	42	29
≥2	19	12	7

Abbreviations: AFP, alpha-fetoprotein; HBsAg, hepatitis B surface antigen; PLCE1, phospholipase C epsilon 1; TNM, tumor-node-metastasis.

Figure 4 Kaplan–Meier analysis of OS and DFS curves of patients with HCC based on PLCE1 expression as positive or negative.

Notes: (A) OS curve of patients with HCC based on PLCE1 expression; (B) DFS curve of patients with HCC based on PLCE1 expression. HCC patients with PLCE1+ showed markedly better OS and DFS rates than those with PLCE1−.
Abbreviations: DFS, disease-free survival; HCC, hepatocellular carcinoma; OS, overall survival; PLCE1, phospholipase C epsilon-1.

Table 2 Univariate analysis of parameters associated with OS and DFS

Features	OS			DFS
	Median survivaltime (months)	95% CI	P-value	Median survivaltime (months)	95% CI	P-value
PLCE1			<0.001			<0.001
Positive	51	36.200–65.800		28	23.202–32.798
Negative	15	11.080–18.920		9	7.831–10.169
Age (years)			0.857			0.230
≥50	33	25.867–40.133		21	16.924–25.076
<50	29	19.466–38.534		21	16.247–25.753
Gender			0.413			0.334
Male	32	25.793–38.207		21	17.875–24.125
Female	27	11.734–42.266		21	0.000–45.661
Tumor size (cm)			0.023			0.014
>5	27	22.156–31.844		18	12.550–23.450
≤5	51	34.951–67.049		32	20.409–43.591
Tumor nodule			0.294			0.174
Single	29	23.500–34.500		32	16.534–47.466
Multiple	47	18.334–75.666		20	16.247–23.753
Tumor capsulae			<0.001			<0.001
Present	52	24.471–79.529		27	22.150–31.850
Absent	17	7.473–26.527		9	3.713–14.287
Vascular invasion			<0.001			<0.001
Yes	23	18.624–29.376		15	9.213–20.787
No	49	19.254–79.267		38	22.443–53.557
TNM stage			<0.001			<0.001
I–II	52	27.581–76.419		29	21.298–36.702
III–IV	18	10.562–25.438		9	7.767–10.233
Edmondson grade			0.006			0.016
I–II	38	23.610–52.390		25	19.089–30.911
III–IV	23	15.765–30.235		17	11.394–22.606
Cirrhosis			0.956			0.902
Present	31	25.971–36.029		20	15.785–24.215
Absent	24	10.933–37.067		21	14.467–27.533
AFP (ng/mL)			0.008			0.640
≥20	27	21.905–32.095		20	15.930–24.070
<20	51	33.538–68.462		23	19.027–26.973
Child–Pugh grade			0.748			0.937
A	31	23.043–38.957		21	17.505–24.495
B	31	18.479–43.521		21	16.417–25.583
HBsAg			0.803			0.478
Positive	29	22.426–35.574		21	16.902–25.098
Negative	31	24.898–37.102		21	16.639–25.361

Abbreviations: AFP, alpha-fetoprotein; CI, confidence interval; DFS, disease-free survival; HBsAg, hepatitis B surface antigen; OS, overall survival; PLCE1, phospholipase C epsilon 1; TNM, tumor-node-metastasis.

Table 3 Multivariate analysis of prognostic features associated with OS and DFS

Features	OS			DFS
	HR	95% CI	P-value	HR	95% CI	P-value
PLCE1 (positive vs negative)	3.356	1.847–6.096	<0.001	2.335	1.349–4.043	0.003
AFP, ng/mL, (≥20 vs <20)	0.528	0.299–0.930	0.027	–	–	–
Tumor size, cm, (>5 vs ≤5)	1.300	0.734–2.301	0.368	1.364	0.826–2.254	0.226
Vascular invasion (no vs yes)	3.718	1.852–7.464	<0.001	2.670	1.531–4.655	0.001
TNM stage (I–II vs III–IV)	1.677	0.921–3.053	0.091	1.825	1.055–3.158	0.032
Edmondson grade (I–II vs III–IV)	1.149	0.651–2.028	0.633	0.872	0.507–1.498	0.620
Tumor capsluae (absent vs present)	2.228	1.177–4.216	0.014	2.124	1.208–3.732	0.009

Abbreviations: AFP, alpha-fetoprotein; CI, confidence interval; DFS, disease-free survival; HR, hazard ratio; OS, overall survival; PLCE1, phospholipase C epsilon 1; TNM, tumor-node-metastasis.