TY - JOUR
T1 - Marrow stromal cells induce B7-H1 expression on myeloma cells, generating aggressive characteristics in multiple myeloma
AU - Tamura, H.
AU - Ishibashi, M.
AU - Yamashita, T.
AU - Tanosaki, S.
AU - Okuyama, N.
AU - Kondo, A.
AU - Hyodo, H.
AU - Shinya, E.
AU - Takahashi, H.
AU - Dong, H.
AU - Tamada, K.
AU - Chen, L.
AU - Dan, K.
AU - Ogata, K.
N1 - Funding Information:
This work was supported in part by a Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (20591157).
PY - 2013/2
Y1 - 2013/2
N2 - Tumor-associated B7-H1 molecules inhibit antitumor immunity in some malignancies. We found that B7-H1 expression on patient myeloma cells and human myeloma cell lines (HMCLs) was upregulated by cultivating the cells with autologous stromal cells and the human stromal cell line HS-5. Among major cytokines produced by HS-5 cells, interleukin (IL)-6-induced B7-H1 expression on HMCLs. Moreover, HS-5 cell-mediated B7-H1 expression was downregulated by inhibiting IL-6. B7-H1+ HMCLs were more proliferative and less susceptible to antimyeloma chemotherapy compared with B7-H1-HMCLs. Moreover, the former cells showed higher levels of Bcl-2 and FasL expression than the latter. Finally, B7-H1 molecules on HMCLs induced T-cell apoptosis and anergy of tumor-specific T cells. Consistent with these in vitro observations, patients whose myeloma cells expressed high levels of B7-H1 had higher myeloma cell percentages in the bone marrow (BM) and higher serum lactate dehydrogenase levels compared with other myeloma patients. In addition, B7-H1 expression levels were often upregulated after myeloma patients relapsed or became refractory to therapy. Our data indicate that the BM microenvironment upregulates B7-H1 expression on myeloma cells, which links to the two biological actions of inducing T-cell downregulation and enhancing aggressive myeloma-cell characteristics. Modulating the B7-H1 pathway may be worthwhile in myeloma.
AB - Tumor-associated B7-H1 molecules inhibit antitumor immunity in some malignancies. We found that B7-H1 expression on patient myeloma cells and human myeloma cell lines (HMCLs) was upregulated by cultivating the cells with autologous stromal cells and the human stromal cell line HS-5. Among major cytokines produced by HS-5 cells, interleukin (IL)-6-induced B7-H1 expression on HMCLs. Moreover, HS-5 cell-mediated B7-H1 expression was downregulated by inhibiting IL-6. B7-H1+ HMCLs were more proliferative and less susceptible to antimyeloma chemotherapy compared with B7-H1-HMCLs. Moreover, the former cells showed higher levels of Bcl-2 and FasL expression than the latter. Finally, B7-H1 molecules on HMCLs induced T-cell apoptosis and anergy of tumor-specific T cells. Consistent with these in vitro observations, patients whose myeloma cells expressed high levels of B7-H1 had higher myeloma cell percentages in the bone marrow (BM) and higher serum lactate dehydrogenase levels compared with other myeloma patients. In addition, B7-H1 expression levels were often upregulated after myeloma patients relapsed or became refractory to therapy. Our data indicate that the BM microenvironment upregulates B7-H1 expression on myeloma cells, which links to the two biological actions of inducing T-cell downregulation and enhancing aggressive myeloma-cell characteristics. Modulating the B7-H1 pathway may be worthwhile in myeloma.
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U2 - 10.1038/leu.2012.213
DO - 10.1038/leu.2012.213
M3 - Article
C2 - 22828443
AN - SCOPUS:84873569613
SN - 0887-6924
VL - 27
SP - 464
EP - 472
JO - Leukemia
JF - Leukemia
IS - 2
ER -