OBJECTIVE:To investigate whether cancer stem cells(CSCs) more efficiently activating platelets and evading immune surveillance than non-CSCs thus promoting metastasis.METHODS:We enriched and identified sphereforming c...OBJECTIVE:To investigate whether cancer stem cells(CSCs) more efficiently activating platelets and evading immune surveillance than non-CSCs thus promoting metastasis.METHODS:We enriched and identified sphereforming cells(SFCs) and coincubated washed platelets with several platelet activators including collagen,4T1 and SFCs.Platelet-coating tumor cells,platelet activation and TGF-β1 release were analyzed.Then natural kell cells(NK) were incubated with supernatants of different activated platelet samples what we called sample release(SR).The degranulation assay and NKG2 D expression on NK cells were conducted by flow cytometry.Finally tissue factor(TF) expression of SFCs or 4T1 were evaluated by western blot.RESULTS:Breast cancer cell line 4T1 could form spheres in serum-free medium at low adherence.Sphere-forming cells expressed high levels of the CD24-/lowCD44 + stem cell phenotype.Both sphere-forming cells or 4T1 were coated with abundant platelets while sphere-forming cells induced significantly higher expression of platelet activating receptor CD62 p than 4T1 did(P < 0.01).And sphere-forming cells induced platelets to produce more TGF-β1 than 4T1 did(P < 0.01).Furthermore,sample releases induced by sphere-forming cells caused more vigorous inhibition of NK cells antitumor reactivity(P < 0.05) and reduced NKG2 D expression(P < 0.01).The final results showed that sphere-forming cells expressed higher levels of TF than 4T1(P < 0.05).CONCLUSION:Our findings indicate that CSCs could efficiently activate platelets,induce platelets to secrete more TGF-β1,decrease NKG2 D expression and inhibit antitumor activity of NK cell,compared with 4T1.And higher levels of TF expression of CSCs may account for this correlation of CSCs and platelets.展开更多
基金Supported by the National Natural Science Foundation of China(the Research of Traditional Chinese Medicien Regulating the Tumor Metastasis due to Cancer Stem Cell Related Expression of TF and TF/FⅦSignal Pathway Based on Traditional Chinese Mediceory of"Fu Du",No.81273947)the International S&T Cooperation Program Office of China(Herbal Medicine with Different Treatment Principles on Regulating the Biological Behaviour of Cancer Stem Cells and its Regulatory Factors,No.2013DFA32540)
文摘OBJECTIVE:To investigate whether cancer stem cells(CSCs) more efficiently activating platelets and evading immune surveillance than non-CSCs thus promoting metastasis.METHODS:We enriched and identified sphereforming cells(SFCs) and coincubated washed platelets with several platelet activators including collagen,4T1 and SFCs.Platelet-coating tumor cells,platelet activation and TGF-β1 release were analyzed.Then natural kell cells(NK) were incubated with supernatants of different activated platelet samples what we called sample release(SR).The degranulation assay and NKG2 D expression on NK cells were conducted by flow cytometry.Finally tissue factor(TF) expression of SFCs or 4T1 were evaluated by western blot.RESULTS:Breast cancer cell line 4T1 could form spheres in serum-free medium at low adherence.Sphere-forming cells expressed high levels of the CD24-/lowCD44 + stem cell phenotype.Both sphere-forming cells or 4T1 were coated with abundant platelets while sphere-forming cells induced significantly higher expression of platelet activating receptor CD62 p than 4T1 did(P < 0.01).And sphere-forming cells induced platelets to produce more TGF-β1 than 4T1 did(P < 0.01).Furthermore,sample releases induced by sphere-forming cells caused more vigorous inhibition of NK cells antitumor reactivity(P < 0.05) and reduced NKG2 D expression(P < 0.01).The final results showed that sphere-forming cells expressed higher levels of TF than 4T1(P < 0.05).CONCLUSION:Our findings indicate that CSCs could efficiently activate platelets,induce platelets to secrete more TGF-β1,decrease NKG2 D expression and inhibit antitumor activity of NK cell,compared with 4T1.And higher levels of TF expression of CSCs may account for this correlation of CSCs and platelets.
