Abstract
Renal cell carcinoma (RCC) is the most common form of kidney cancer. Vascular endothelial growth factor-C (VEGF-C) and its receptor, VEGFR-3, are involved in lymphangiogenesis. The aim of the present study was to investigate the expression levels of VEGF-C and VEGFR-3 in RCC, and their association with lymphatic vessel density (LVD) and lymph node metastasis. The mRNA expression levels of VEGF-C in 40 RCC tissues and 10 normal renal tissues were determined by reverse transcription-semiquantitative PCR. The differential expression of VEGF-C and VEGFR-3 was examined by immunohistochemistry. Using an anti-D2-40 antibody as a lymphatic marker, the morphology and structure of lymphatic vessels in tissues was examined, and the LVD was calculated. VEGF-C mRNA expression in RCC tissues was higher than that in normal renal tissues, and VEGF-C mRNA expression in the lymph node metastasis group was higher than that in the non-lymph node metastasis group. The positive expression rate of VEGF-C and VEGFR-3 in RCC tissues was significantly higher than that in normal renal tissues. VEGF-C expression in the lymph node metastasis group was significantly higher than that in the non-lymph node metastasis group, and the positive expression of VEGF-C was associated with the clinical staging of RCC. In addition, there was a correlation between VEGF-C and VEGFR-3 expression in tumor cells. The LVD around the tumor was higher than that in the center of the tumor tissues and normal renal tissues, and it was closely associated with lymphatic invasion and lymph node metastasis. Overall, the current findings demonstrated that the VEGF-C/VEGFR-3 signaling pathway promoted lymphangiogenesis around the tumor and provided an approach for tumor lymphatic invasion and lymph node metastasis. Therefore, VEGFC and VEGFR-3 expression may serve an important role in the initiation and development of RCC.