Nuclear ING2 expression is reduced in osteosarcoma.

Osteosarcoma is a high-grade malignant bone tumor. Loss of inhibitor of growth 2 (ING2) expression has been demonstrated in numerous types of cancers. However, no study has shown the relationship between ING2 expression and osteosarcoma. In the present study, we confirmed that the levels of ING2 mRNA and protein were lower in cancer tissues than these levels in normal tissues. Loss of nuclear ING2 protein was significantly associated with a decreased survival time of patients. Osteosarcoma cells were transfected with ING2 protein without a nuclear localization signal or intact ING2 protein to examine the effects of exogenous expression of ING2 in vitro. Compared to the control cells, intact ING2-expressing cells exhibited increased apoptosis, G1 phase arrest and senescence. Taken together, these results suggest that ING2 acts as a tumor suppressor in osteosarcoma.