Effects of thalidomide on Annexin Ⅱ gene regulation

Objective To investigate the effect of thalidomide on Annexin Ⅱ (AnxA2) gene regula-tion in multiple myeloma cell line RPMI8226 and human microvascular endothelial cell line HMEC-1 cells in vitro, and explore the potential mechanism of thrombosis induced by thalidomide. Methods RPMI8226 and HMEC-I cells were cultivated in vitro. Real time quantitative PCR (RQ-PCR) was used to detect the influ-ence of thalidomide at different concentration on the expression of AnxA2 mRNA, flow cytometry(FCM) and confocal microscopy were used to detect the cell surface protein level after the samples were stimulated with different concentrations of thalidomide. Results AnxA2 mRNA level in RPMI8226 cells treated with thalido-mide at 12.5 μg/ml, 25.0 μg/ml and 50.0 μg/ml was decreased compared with the control group (0.60 ±0. 15, 0.33 ± 0. 14, 0.42 ±0. 16, vs 1.07 ±0. 16, respectively, P <0.05)and did so in HMEC-1 cells (0.21 ±0.20, 0.08 ±0.08, 0.17 ±0. 16 vs 1.16 ±0.24, respectively, P <0.05). The AnxA2 protein lev-el in RPMI8226 cells treated with above mentioned concentrations of thalidomide was also decreased compared with the control (3.39 ± 0.32, 2.82 ± 0.28, 3.21 ± 0.23 vs 5.53 ± 0.32, repectively, P < 0. 05) and that did so in HMEC-1 cells (0.72±0. 11, 0.64 ±0.08, 0.67 ±0.08 vs 1.40 ±0. 15, respectively, P<0.05). Conclusions Thalidomide can inhibit the expression of AnxA2 mRNA and protein in RPMI8226 and HMEC-1 cells, which may be one of the mechanisms for the development of thrombosis induced by thalido-mide in multiple myeloma patients.