| ObjectiveIFN-a has variety of biologic properties, including antiviral, immunomodulatory, antiproliferative and antiangiogenic effects. Previous studies showed that IFN-a exerted its inhibitory effect on HCC growth mainly through antiangiogenesis by down-regulation of VEGF-A. In this study, we investigate the inhibitory effect of IFN-a on the VEGF and HGF expression in nude mice orthotopic transplanted with human hepatocelllular carcinoma with highly metastatic potential.Material and MethodsEstablish an nude mice mode with highly metastatic potential (LCI-D20) with HCC-LM3 transfected with green-fluorescent protein (GFP) gene in nude mice,1 day after transplantation, nude mice were divided into two groups randomly and then treated with IFN-a (1.5*104u/kg-d) in treatment group and normal saline in control group, respectively. Sacrificed the mice at the end of 2w,3w,4w and 5w. the volume of tumor and intrahepatic metastases in two groups were compared. The microvessel density (MVD) of tumor was observed by immunohistochemistry. PCR-array was used to detect the gene expression, Real-time RT-PCR was used to validate the difference.ResultsThe tumor size in treatment group and control group are 0.11±0.03 cm3 and 0.99±0.37 cm3, respectively (P< 0.05), The metastasis rate in treatment group and control group are 33.3%(4/12) and 83.3%(10/12), respectively (P< 0.05). The average number of metastatic nodules in treatment group and control group are 0.67±0.31 and 1.91±0.43, respectively (P< 0.05). intratumoral MVD in treatment group and control group are 3.19±0.52 and 4.85±0.72, respectively (P< 0.05). The date from PCR-array showed that IFN-a can significantly inhibit the VEGF and HGF expression at the end of 4th week. The VEGF expression (-ACT) in treatment group and control group are-8.16±0.54 and-6.95±0.86, respectively (P< 0.05). The HGF expression in treatment group and control group are-11.62±0.63 and-10.56±0.48, respectively (P< 0.05).ConclusionIFN-a significantly inhibited the growth of tumor and the intrahepatic metastases of HCC-LM3, it also decrease the intratumoal MVD and suppress the HGF expression, may be the inhibition of HGF and VEGF is the mechanism of anti-angiogenesis effect of IFN-a. Hepatocellular carcinoma (HCC) is a common solid organ malignancy worldwide, with about 600,000 new cases diagnosed each year, and it is the third most common cause of cancer-related death worldwide. VEGF targeted therapy is a promising treatment for hepatocellular carcinoma (HCC), but its clinical benefit is often accompanied by acquired resistance. Recently, the crosstalk between DLL4/Notch and VEGF is widely studied, more and more research suggested that DLL4 holds promise as an additional strategy for angiogenesis-based cancer therapy. The aim of study is to assess the expression and prognostic value of DLL4 in HCC after curative resection.Material and MethodsPaired tumor with corresponding peritumoral liver tissues from patients who underwent curative resection in Zhongshan Hospital during January 1999 and march 2008 were enrolled. DLL4 and CD31 expression was investigated in tumor and peritumoral liver tissues from 105 HCC patients by immunohistochemistry in tissue microarrays. The peritumoral DLL4 expression and intratumoral DLL4 expression were compared. Its association with clinicopathologic features and patients'outcomes were evaluated, and its correlation with expression of CD31 and VEGF-A was investigated.ResultDLL4 staining was mainly on the cytoplasm or/and membrane in tumor or peritumoral liver tissue, respectively, its expression can be also observed in the cytoplasm of the endothelial cells lining vessels adjacent to cancer and vessels in the tumor tissue. Most of the stroma cells were negative staining. There is no significant difference of DLL4 protein expression between peritumoral liver tissue and corresponding tumor tissue (P=0.528). Low intratumoral DLL4 expression is associated with younger and poor differentiation (P= 0.049 and P= 0.028, respectively), whereas patients with low peritumoral DLL4 expression had a high incidence of large tumor size and poor differentiation (P= 0.037 and P= 0.004, respectively). In univariate analysis, patients with low peritumoral DLL4 expression had poor prognosis. The median OS time and DFS time were 25.3 and 23.2 months, respectively, in patients with low peritumoral DLL4 expression; both were significantly shorter than patients with high peritumoral DLL4 expression (107.0 months and 87.7 months, respectively; P= 0.002 and P= 0.017, respectively). Intratumoral DLL4 expression was associated with OS but not DFS (P= 0.031 and P = 0.186, respectively). The median OS time in patients with low intratumoral DLL4 expression were significantly shorter than patients with high intratumor DLL4 expression (45.2 months vs 107.0 months). All clinicopathological factors were adopted in multivariate Cox proportional hazards analysis. DLL4 expression in peritumoral liver tissue was an independent risk factor for OS (HR= 2.042; 95%CI, 1.130 to 3.688; P= 0.018) and DFS (HR=1.979; 95%CI,1.071 to 3.733; P= 0.030), whereas low intratumoral DLL4 expression was an independent risk factor for OS (HR=2.029; 95%CI,1.107 to 3.717; P= 0.022) but not DFS. CD31 staining was mainly on the cytoplasm or/and membrane of the endothelial cells lining vessels adjacent to cancer and vessels in the tumor tissue. CD31 expression was found to be negatively correlated with DLL4 expression in peritumoral liver tissue (r =-0.229, P= 0.019), but not in tumor tissue (r=-0.131, P= 0.073). Furthermore, VEGF-A expression data were obtained from the same cohort, and its relation with DLL4 expression was analyzed. DLL4 expression were positively correlated with VEGF-A expression in peritumoral liver tissue (r= 0.248, P= 0.011) and in tumor (r = 0.154, P= 0.012).ConclusionsLow DLL4 expression was associated with tumor recurrence and survival after resection of HCC. DLL4 is potential to be a useful prognostic factor for HCC after curative resection. Activation of DLL4/Notch in the tumor microenvironment might be a novel means of HCC adjuvant therapy. |
PDF Full Text Request