[Effect of BAFF/APRIL mRNA expression induced by glucocorticoid and bortezomib in multiple myeloma cells in vitro].

The study was purposed to detect BAFF/APRIL gene expression changes in bone marrow mononuclear cells (BMMNC) and myeloma cell line U266 after interference with glucocorticoid and bortezomib. After separation of BMMNC from 7 patients with multiple myeloma, BAFF/APRIL mRNA expression in BMMNC and U266 cell line was detected by real-time PCR after treated with dexamethasone 100, 200 µg/ml, methylprednisolone 100, 200 µg/ml, bortezomib 0.1 µg/ml alone and dexamethasone or methylprednisolone combined with bortezomib respectively for 48 hours. The results showed that U266 cells and BMMNC of untreated MM patients highly expressed BAFF/APRIL genes. When dexamethasone, methylprednisolone or bortezomib was added to U266 cells or BMMNC alone, BAFF/APRIL gene expression decreased as compared with the blank control (p < 0.01). The inhibiting effect of bortezomib to BAFF/APRIL expression was obviously strong(p < 0.05). When dexamethasone or methylprednisolone combined with bortezomib, the BAFF/APRIL gene expression further decreased compared with dexamethasone or methylprednisolone alone (p < 0.01). As compared with the group of methylprednisolone combined with bortezomib, BAFF/APRIL gene expression decreased in dexamethasone combined with bortezomib with a statistically significant difference (p < 0.05). It is concluded that the expression of BAFF/APRIL gene is down-regulated after bing treated with glucocorticoids and bortezomib, which suggests that besides the glucocorticoid receptor and proteasomes targets, BAFF/APRIL and their receptor sites may be new targets of glucocorticoids and bortezomib.