To investigate the expression level and prognostic value of cell division cycle protein 10 dependent transcript 1 (CDT1) in patients with hepatocellular carcinoma (HCC).

Clinical data of 237 HCC patients (HCC group) who underwent hepatectomy in the No.900 Hospital of Joint Logistics Support Force of PLA from January 2014 to January 2016 were retrospectively analyzed, and 200 healthy volunteers were assigned into the control group. The informed consents of all patients were obtained and the local ethical committee approval was received. In the HCC group, 149 patients were male and 88 female, aged from 31 to 82 years, with a median age of 51 years. In the control group, 110 patients were male and 90 female, aged from 30 to 70 years, with a median age of 48 years. The expression level of CDT1 protein in the HCC and adjacent tissues was detected by Western blot. The expression level of CDT1 mRNA in the HCC tissues was determined by fluorescence in situ hybridization. The expression level of CDT1 mRNA in the serum was detected by RT-PCR. According to the average relative expression level of CDT1 mRNA in the HCC tissues, patients in the HCC groups were further divided into the high and low CDT1 expression groups. The relationship between the expression of CDT1 mRNA in the HCC tissues and clinicopathological parameters of HCC patients before operation was assessed by t test or one-way ANOVA. The relationship between serum expression of CDT1 mRNA and serum AFP level was determined by the linear correlation analysis. Survival analysis was conducted by Kaplan-Meier method and Log-rank test. The influencing factors of postoperative recurrence and metastasis of HCC were identified by multivariate Cox regression model.

The average relative expression level of CDT1 mRNA in the HCC tissues was 2.20±0.18, significantly higher than 1.86±0.24 in the adjacent tissues (t=16.705, P<0.05). The relative expression level of serum CDT1 mRNA in the HCC group was 1.62±0.18, significantly higher than 1.34±0.15 in the control group (t=17.398, P<0.05). In the HCC group, the expression level of CDT1 protein in the HCC tissues was significantly higher than that in adjacent tissues. The relative expression level of CDT1 mRNA in the HCC tissues was correlated with preoperative tumor diameter, tumor encapsulation, preoperative HBsAg, microvascular invasion and tumor differentiation of patients with HCC (t=-3.107, -8.352, -2.221, -2.981, 3.745; P<0.05). The relative expression of serum CDT1 mRNA before surgery and after recurrence of HCC was positively correlated with serum AFP level (r=0.507, 0.403; P<0.05). The 3-year recurrence rates were 35.11% and 24.53% in the high and low CDT1 expression groups, and the 5-year survival rates were 56.49% and 73.58%, respectively, where significant difference was observed (χ²=6.520, 5.566; P<0.05). Multivariate Cox regression analysis showed that the relative expression level of CDT1 mRNA≥2.20 was an independent risk factor for the postoperative HCC recurrence and metastasis (HR=1.950, 95%CI: 1.217-3.124, P<0.05).

CDT1 is highly expressed in HCC patients. It is associated with the recurrence and progression of HCC. High recurrence rate and poor prognosis are observed in patients with high expression of CDT1.