[Expression of membrane/soluble MHC class I chain-related molecule A and NKG2D receptor in osteosarcoma and its clinical significance].

Objective: To study the expression of membrane MICA (mMICA), soluble MICA (sMICA) and NKG2D receptor in cases of osteosarcoma and to analyze its clinical significance.

Methods: Expression of mMICA in osteosarcoma tissue of 43 cases was detected with immunohistochemistry. Expression of NKG2D in peripheral blood lymphocytes of 16 cases was analyzed by flow cytometry. Serum level of soluble MICA (sMICA) was measured by ELISA.

Results: mMICA was widely expressed in osteosarcoma tissue (37/43). Expression of NKG2D in peripheral blood lymphocytes was significantly decreased. High levels of mMICA and NKG2D expression were associated with better differentiation and earlier tumor stage of osteosarcoma (P < 0.05). A significant increase in serum level of sMICA was demonstrated in patients with metastasis and advanced tumor.

Conclusions: The mMICA expression in tumor tissue, NKG2D expression in peripheral lymphocytes and serum sMICA level correlate with the differentiation and stage of osteosarcoma. These parameters may thus represent potential diagnostic and prognostic markers in patients with osteosarcoma. Manipulation of the MICA-NKG2D pathway may become a target of immunotherapy for osteosarcoma.