Article

Unfavorable clinical implications for HLA-G expression in acute myeloid leukemia.

Medical Research Center, Taizhou Hospital of Zhejiang province, Wenzhou Medical College, Linhai, Zhejiang 317000, People's Republic of China.
Journal of Cellular and Molecular Medicine (Impact Factor: 4.75). 12/2007; DOI: 10.1111/j.1582-4934.2007.00175.x
Source: PubMed

ABSTRACT Human leukocyte antigen-G (HLA-G) molecule exerts multiple immunoregulatory functions which have been suggested to contribute to the immune evasion of tumor cells. Studies on HLA-G expression in malignant hematopoietic diseases are controversial and the functions of HLA-G on this context are limited. In the current study, HLA-G expression was analyzed in different types of patients: de novo acute myeloid leukemia (AML, n=54), B cell acute lymphoblastic leukemia (B-ALL, n=13), chronic myeloid leukemia (CML, n=9) and myelodysplastic syndrome (MDS, n=11). HLA-G expression was observed in 18.5% cases of AML, 22.2% in CML and 18.2% in MDS, but not in B-ALL patients. In AML, HLA-G-positive patients had a significant higher bone marrow leukemic blast cell percentage when compared with that of HLA-G negative patients (p<0.01). Total T cell percentage was dramatically decreased in HLA-G positive patients (p<0.05). Cytogenetic karyotyping results showed that all HLA-G positive AML patients (n=5) were cytogenetically abnormal which was markedly different from that of HLA-G negative patients (p<0.01). ex vivo cytotoxicity analysis revealed that HLA-G expression in AML leukemic cells could directly inhibit NK cell cytolysis (p<0.01). These findings indicated that HLA-G expression in AML is of unfavorable clinical implications, and that HLA-G could be a potential target for therapy.

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