ABSTRACT
<p><b>OBJECTIVE</b>To investigate the expression of RKIP, p65 and pERK in hepatocellular carcinoma (HCC) and theIr correlation with invasion and metastasis of HCC.</p><p><b>METHODS</b>Reverse transcription polymerase chain reaction (RT-PCR) was used to detect the expression of RKIP mRNA. The expression levels of RKIP, p65 and pERK proteins in HCC tumor and peritumoral tissues were determined by immunohistochemistry and Western blot analysis. Statistical analysis was performed to determine the relationship between their expression and clinicopathological parameters.</p><p><b>RESULTS</b>RKIP protein expression level (RKIP/actin) was 0.579 ± 0.380 in HCCs, 1.178 ± 0.659 in peritumoral tissues and 1.115 ± 0.442 in normal liver tissues. The pERK protein level was 1.023 ± 0.478, 0.605 ± 0.367 and 0.461 ± 0.293, p65 protein level was 0.83 ± 0.376, 0.63 ± 0.337 and 0.466 ± 0.345, respectively. Immunohistochemistry analysis showed that the RKIP positive rates in HCCs, peritumoral tissues and normal liver tissues, were 22.2%, 86.0%, and 93.8%, positive rates of p65 were 73.6%, 56.0% and 37.5%, positive rates of pERK were 65.3%, 38.0% and 31.3%, respectively. Statistical analysis revealed that there was a significant difference in RKIP protein expression levels (P < 0.05), but no significant difference in RKIP mRNA expression levels (P > 0.05) among HCC tumors, peritumoral tissues and normal liver tissues. The p65-positive and pERK-positive rates were higher in tumor tissues than that in peritumoral tissues and in normal liver tissues (P < 0.05), but RKIP-positive rates were lower in tumor tissues than that in paritumoral tissues and normal liver tissues (P < 0.05). RKIP protein expression levels were significantly lower in HCCs with intrahepatic or lymphatic metastasis than that in without. The RKIP positive rates in moderately and well differentiated HCCs were significantly higher than that in poorly differentiated HCCs. There was a relationship between RKIP and pERK expressions (P = 0.04), but RKIP expression was not correlated with p65 expression in HCCs (P = 0.143).</p><p><b>CONCLUSIONS</b>Our findings indicate that the down-regulation of RKIP expression may serve as a predictive marker for HCC development, progression and metastasis, which may contribute to the elevated ERK activity. The inhibiting effect of RKIP on invasion and metastasis of liver cancer cells may be due to the down-regulation of pERK expression rather than p65 expression.</p>
Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Carcinoma, Hepatocellular , Metabolism , Pathology , Down-Regulation , Extracellular Signal-Regulated MAP Kinases , Metabolism , Gene Expression Regulation, Neoplastic , Liver , Metabolism , Liver Neoplasms , Metabolism , Pathology , Lymphatic Metastasis , Neoplasm Invasiveness , Phosphatidylethanolamine Binding Protein , Genetics , Metabolism , Phosphorylation , RNA, Messenger , Metabolism , Transcription Factor RelA , MetabolismABSTRACT
Objective: To study the expressions of vascular endothelial growth factor D (VEGF-D) and its receptor fms-like tyrosine kinase-4 (Flt-4) and to determine whether the presence of VEGF-D and Flt-4 was associated with the clinicopathologic characteristics and prognosis of pancreatic cancer. Methods: The expressions of VEGF-D and Flt-4 proteins were examined by immunohistochemical staining in 48 pancreatic cancer tissues, 32 adjacent pancreatic tissues, and 13 normal pancreatic tissue samples. Differences in distribution of VEGF-D or Flt4 were analyzed using the χ2 test. Kaplan-Meier survival analysis was used to estimate survival time and log-rank test was used to compare differences in survival time between the patients with or without VEGF-D or Flt-4 expression. Results: Immunohistochemical analysis revealed that the positive staining rates of VEGF-D and Flt-4 in pancreatic cancer tissues were significantly lower than that in para-cancerous tissues (P < 0.05), but significantly higher than that in normal pancreatic tissues (P < 0.05). Pancreatic cancer tissues with lymph node metastasis had higher expression of VEGF-D and Flt-4 compared with those without lymph node metastasis (P < 0.01). The median survival time and 1-, 2-, 3-year survival rate of VEGF-D-or Flt-4-positive patients were significantly decreased compared with VEGF-D- or Flt-4-negative patients (P < 0.05). Conclusion: VEGF-D and Flt-4 may contribute to lymph node metastasis and may serve as a prognostic factor for pancreatic cancer patients.