The Interaction Between L-selectin And Chemokine Receptor CXCR4 In Mouse Lymphoma P388D1 Cells

BackgroundTumor seriously threats people's lives and health. But the cure rate of cancer is low, because of metastasis,differentiation and non-radical Therefore, it is particularly important to study tumor metastasis.L-selectin is a type-I transmembrane glycoprotein,and its calcium-dependent lectin domain at the N-terminal,namely the carbohydrate recog-nition domain.L-selectin plays an important role in lymphocyte homing, leukocyte rolling and adhesion on endothelial cells. Recent studies revealed that mannose receptor(MR) which serves as a L-selectin receptor is probably involved in tumor cell lymphogeneous metastasis.It indicates that the expression of L-selectin homing recepters of P388D1 cell line is a prerequisite for their dissemination into peripheral lymph nodes.Chemokine is a kind of cytokines, which can been induced.it is a kind of small polypeptide molecular and result from many cells.CXCR4 is CXCL12 (SDF-1) specific receptor, whose main function is mediating lymphatic metastasis of tumor cells by binding chemokine CXCL12.It not only express on cell surface,but also express in cytoplasm.CXCR4 widely express in central nerve system and immunity system and nearly 30 kinds of tumor cells. Previous studies showed that the interaction of CXCR4/SDF-1 can regulate the capability of MMP2 and MMP9 secreting in HcaF and HcaP cells to affect the potential for lymphogenous metastasis.It has been found that the expression of L-selectin and CXCR4 exists on T lymphocytes in normal human blood. L-selectin-mediated signals specifically enhanced the expression and function of CXCR4, suggesting a novel mechanism for the modulation of lymphocyte activation during cell adhesion and transmigration.P388D1 cells belong to Lymphatic system of the tumor cells. The ex-pression of CXCR4 and L-selectin is also showed on membrane of P388D1. It has been demonstrated that L-selectin ligand is expressed on endothelium in the lymph nodes.And it may upregulate the functional expression of CXCR4,when combined with L-selectin,then promote tumor cells through high endothelial vein (HEVs) into lymph nodes from blood vessels.This phenomenon will affect tumor lymphatic metastasis.ObjectivesThe main purpose of this study is to use the natural L-selectin ligand fucoidan treated P388D1 cells. Then, we observe the relationship and the function between L-selectin and chemokine receptor CXCR4 in mouse lymphoma P388D1 cells, and further explore the molecular mechanism of tumor metastasis.Method1)Observe changes of the functional of CXCR4 on P388D1 cells. Intracellular calcium mobilization was assessed in P388D1 cells exposed to SDF-1,after treated P388D1 cells by Fucoidan, HcaF cells as a control; Observe changes of functional of CXCR4 on P388D1 cells,after treated by heparin,Fucoidan and chitosan oligosaccharide represent respectively control; HcaF cells was transfected by L-selectin,then observe changes of functional of CXCR4 on HcaF cells after treated by Fucoidan2)P388D1 was treated by Fucoidan P388D1,then exposed to SDF-1 we observe the secretion of matrix metalloproternase MMP2 and MMP9 by Gelatin zymographyResult1)CXCR4 and L-selectin were expressed on P388D1 cells. The control group Hca-F cells expressed CXCR4, but L-selectin were absent.2)With the Fucoidan stimulating P388D1 cells,intracellular calcium mobilization was assessed in P388D1 cells exposed to SDF-1.we found the functional of CXCR4 was increased, while the Hca-F cells were not found; With the heparin (450U) stimulating P388D1 cells,Fucoidan and chitosan oligosaccharide respectively, we found the functional of CXCR4 was increased except chitosan oligosaccharide; With the Fucoidan stimulating HcaF cells after transfection of L-selectin,we found that the functional of CXCR4 was increased.3)With the natural L-selectin ligand Fucoidan stimulating P388D1 cells, Gelatin zymography showed that the secretion of MMP2 was increased, MMP9 was absent.ConclusionL-selectin may be combined with sulfuric acid of the sugar, mobilized intracellular CXCR4 to significantly increase surface CXCR4 expression, which mediated tumor lymphatic metastasis, in mouse lymphoma P388D1 cells.