Expression And Significance Of Lymphatic Vessel Endothelial Hyaluronic Acid Receptor-1 In Rectal Cancer

Background and objectiveThe invasion and metastasis of neoplasm was constituted by some complicated and multi-steps procedure, which related with the adhesion, angiogenesis and lymphatic metastasis of the tumor cells. Recent years, with the discovery of many lymphatic vessel markers such as VEGF-C, VEGF-D, VEGFR-3, LYVE-1, Podoplanin, Prox-1, and so on, the study on the tumor lymphagiogenesis and metastasis has been gradually increased. Among those lymphatic vessel markers, lymphatic vessel endothelial hyaluronan receptor (LYVE-1) was regarded as one of the most specific markers for the lymphatic vessel, which is a receptor specifically expressed on lymphatic vessel endothelial cells. It was not reported at home and abroad to study tumor lymphangiogenesis in rectal cancer using LYVE-1 as a specifically lymphatic vessel endothelial marker. The purpose of the study was to observe the expression of lymphatic vessel endothelial hyaluronic acid receptor-1 (LYVE-1) in rectal cancer and count the microlymphatic vessel density(MLD), then to investigate its relationship with the lymphatic metastasis and biological behaviour of the rectal cancer, combining with the propotional clinical data.METHODSImmunohistochenmistry was used to detect the expression of LYVE-1 in(1) 60 cases of rectal cancer tissue and 40 cases of normal colorectal tissue were collected from April 2005 to October 2006 in the general surgery department of SHANTOU university medical college, the second affiliated hospital. All cases did not include inflammatory bowel diease(IBD). After disposal, we detected the samples with certain kinds of method and analysis the data.(2) LYVE-1 protein expression in rectal cancer tissue and normal rectal tissue was evaluated by SABC of IHC method, and count the microlymphatic vessel density (MLD) in every cases.(3) All of statistical analysis was performed with statistical package SPSS version 13.0 software. RESULTS(1) LYVE-1 was expressed in the endothelial cytoplasm of lymphatic vessels, showing as brown and yellow staining.(2) LYVE-1-positive lymphatics appeared in both peritumor and intratumor of rectal cancer and he intratumoral tissues in rectal cancer.(3) The peritumoral MLD was significantly higher than not only the intratumoral MLD but also the MLD of normal tissues, and the difference between the two latters was also significant.(4) In the peritumoral tissues of rectal cancer, the value of LYVE-1 positive MLD in the peritumoral tissues was markedly relevant to the diameter of tumor, Dukes stage, lymph node metastasis and distant metastasis, rather than pathological classification, location and the infiltration of plasma membrane.(5) In the intratumoral area of rectal cancer, there were no significant relationship bewteen the value of MLD with the clinicopathological parameters such as gender, age, tumor size, infiltration depth, histologic type, gross morphology, differentiation grade, Dukes stage, lymph node metastasis and distant metastasis, and so on.CONCLUSION(1) Lymphangiogenesis exists mainly in the peritumoral tissues of rectal cancer.(2) There was little lymphangiogenesis in intratumoral area of rectal cancer, and the lymphatic vessels were compressed to be a linear state.(2) The more value of the peritumoral area of rectal cancer, the more the metastasis of rectal cancer, lymphangiogenesis may promotes lymphatic metastasis.(3) The detection of the lymphatic vessel density in the peritumoral area of rectal cancer may be a index which can evaluate the lymphangiogenesis of tumor or a judgement of the lymph node metastasis of rectal cancer.