Effects of 2-deoxy-D-glucose and quercetin on osteoblastic differentiation and mineralization in irradiated MC3T3-E1 cells

Ahn, Hyoun Suk; Kim, Kyoung A; Koh, Kwang Joon

Abstract

PURPOSE: To investigate the in vitro response of MC3T3-E1 osteoblastic cells to X-ray in the presence and absence of 2 deoxy-D-glucose (2-DG) and quercetin (QCT).
MATERIALS AND METHODS
The MC3T3-E1 cells were cultured in an alpha-MEM supplemented with 5 mM 2-DG or 10 micrometer QCT and then the cells were incubated for 12 h prior to irradiation with 2, 4, 6, and 8 Gy using a linear accelerator (Mevaprimus, Germany) delivered at a rate of 1.5 Gy/min. At various times after the irradiation, the cells were processed for the analyses of proliferation, viability, cytotoxicity, and mineralization.
RESULTS
Exposure of the cells to X-ray inhibited the tritium incorporation, 3-(4, 5-dimethylthiazol-2yl-)-2, 5- diphenyl tetrazolium bromide (MTT)-reducing activity, and alkaline phosphatase (ALP) activity, and caused cytotoxicity and apoptosis in a dose-dependent manner of the X-ray. This effect was further apparent on day 3 and 7 after the irradiation. RA+2-DG showed the decrease of DNA content, cell viability, and increase of cytotoxicity rather than RA. ALP activity increased on day 7 and subsequently its activity dropped to a lower level. 2-DG suppressed the calcium concentration, but visual difference of number of calcified nodules between RA and RA+2-DG was not noticed. RA+QCT showed the increase of DNA content, cell viability, but decrease of cytotoxicity and subG1 stage cells in the cell cycle, and increased calcified nodules in von Kossa staining rather than the RA. ALP activity showed significant increases on day 7 and subsequently its activity dropped to a lower level.
CONCLUSION
The results showed that the 2-DG acted as a radiosensitizing agent and QCT acted as a radioprotective agent respectively in the irradiated MC3T3-E1 osteoblast-like cells.