| Gastric cancer is one of most common cancer, and the second-highest cause ofcancer-related deaths in the world. Despite more and more research to identify noveldiagnostic and therapeutic agents,patients with advanced gastric cancer suffer from poorprognosis and a poor quality of life, and treatment is also dependent mainly on conventionalcytotoxic chemotherapy.Over the past decade, the importance of the tumor microenvironment (TME) inmolding tumor evolution has become increasingly.The remolding of TME is determined bymolecular interactions not only malignant cells, but also many other non-malignant celltypes that contains many resident (epithelial cells,fibroblasts, vascular endothelial cells)and migratory non-malignant immune cell types (multitudes of innate and adaptive immunecells).Currently, it is accepted that the regulation of immune cells in the TME play animportant role in gastric cancer progression, and that these immune cells within the TMEmay be largely as a therapeutic target for gastric cancer.Mast cells originate from the bone marrow and the immature progenitor cells migrateto peripheral tissue and become mature mast cells in situ. Mast cells are of paramountimportance for allergies, pathogen-induced immune responses during infections,andangiogenesis, as well as innate and adaptive immune regulations.Beside all these roles,mast cells are now more and more being recognized as modulators of the TME. Recentresearch indicate that mast cells promote tumor growth mainly through flowing threeaspects:(1) Mast cells are potential of promoting angiogenesis.Several angiogenic factorsare secreted by mast cells via promotion of angiogenesis,thus contributing to the growth oftumor.(2) Mast cells can facilitate to tissue remolding,thus redounding to tumor growth andmetastasis.(3) Mast cells have immune regulatory effects.However,in human tumortissue,mast cells play role on immunological enhancement or immunosuppression,and haveto be confirmed by further research. Notwithstanding mounting evidences of mast cellaccumulation in tumors, their exact role in tumor microenvironment is still incompletely understood.Particularly noteworthy, it is not clear that phenotype,function and distributionof mast cells in human gastric canccer.Objectives1. To definite the distribution of mast cells in gastric cancer2. To study the phenotypic charaterisitics and chemokine receptors expression of mastcell in gastric cancer.3. To investigate immunosuppressive function of mast cells in gastric cancer.Methods1. The distribution of mast cells in gastric cancerThe flesh peripheral blood and tumor tissue of GC patients were collected in GeneralSurger of Southwest hospital,The Third Medical University.Distribution of mast cells weredetected by flow cytometry and immunohistochemicstry.H&E staining definite gastrichistopathology.The phenotype of mast cells were assayed by flow cytometry.At the sametime,the expression of chemokine receptors on mast cells was examined by flow cytometryin gastric cancer.2. The phenotypic charaterisitics and chemokine receptors expression of mast cell ingastric cancer.The expression of costimulatory molecules CD80CD86and HLA-DR on MC ingastric cancer were detected by flow cytometry.The chemokine receptors of MC werefiltered.3. The inflammatory role of HMC-1on gastric cancer cellsHMC-1cell and BGC-823cell1:1ratio, or individual BGC-823cells or HMC-1cellsalone, were cultured.Afterward, the culture supernatant was collected. The protein levels ofIL-6and TNF-ɑ in the culture supernatant were measured by ELISA.4. The inhibition effect of HMC-1on the proliferation of CD3+T cellsHMC-1were stimulated by20%or40%TCCS, NCCS, TTCS or NTCS.CD3+T cellswere isolated from the peripheral blood of healthy human using magnetic bead and werelabeled with CSFE in vitro.Then,the CD3+T cells and HMC-1with stimulation wereco-cultured for5d..Afterward,the cells were collected to stain for detecting by flowcytometry.At last, the proliferation of CD3+T cells was analyzed. Results1. The distribution of mast cells in GC1.1The percentage of mast cells in peripheral blood of normal people and patientswith GC are respectively0.892%and1.22%.By analysis of statistical, there are have nosignificant difference between the two groups(P>0.05).The percentage of mast cells arerespectively14.39%,11.77%and11.81%in tumor tissue,peritumoral tisswe and normaltisswe.In patient with GC,tumor tissue show a significantly higher MC percentage thanother tissues (P<0.05).1.2It was exhibited by immunohistochemical staining that MC in tumor tissueinfiltrated obviously.These results indicate that the infiltration of MC in tumor tissueclearly increase.2. The phenotypic characteristics and chemokine receptors expression of MC in GC2.1Infiltrating MC expressed costimulatory molecule CD80and CD86in tumor tissuewas not significant different with other tissues,but expressed higher level ofHLA-DR.These results suggest that MC in tumor may have immune suppressivephenotype.2.2MC in tumor tissue expressed hardly CCR2,CXCR3and CXCR2,but showed highexpression level of CXCR4.Meanwhile,the CXCR4expression of MC in peritumoral ornon-tumor tissues reduced obviously.3. The effect of HMC-1on the inflammatory cytokine of tumor cellsIn the coculture system of HMC-1and GC cell lines,BGC-823was individual cultureto secret a lot of IL-6and TNF-ɑ.while BGC-823was culture with HMC-1,the protein levelof IL-6and TNF-ɑ decreased significantly.This show that MC can inhibit pro-inflammatory effect of gastric tumor cells,and MC have immunosuppression function.4. The regulate effect of HMC-1on the proliferation of CD3+T cellsDeal with TCCS TCCS, HMC-1can inhibit the proliferation of CD3+T cells than TTCSor NTCS.Conclusion1. The infiltration of MC in tumor tissue of GC patients clearly increase.MC in tumormay have immune suppressive phenotype.2. MC showed high expression level of CXCR4in tumor tissue3. HMC-1can inhibit the pro-inflammatory effect of gastric tumor cells. 4. Conditional HMC-1inhibit the proliferation of CD3+T cells... |
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