Ectopic cyclin D1 overexpression increases chemosensitivity but not cell proliferation in multiple myeloma
Ectopic cyclin D1 overexpression increases chemosensitivity but not cell proliferation in multiple myeloma
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DOI：
10.3892/ijo_00000110
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发表时间：
2008-12-01
影响因子：
5.2
通讯作者：
Kimura, Akiro
中科院分区：
文献类型：
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作者：
Kuroda, Yoshiaki;Sakai, Akira;Kimura, Akiro
我们建立了细胞周期蛋白D1过表达的骨髓瘤细胞系（RPMI8226），其中转染的细胞周期蛋白D1基因稳定表达。 D1 转染子显示细胞周期蛋白 D2 下调。细胞增殖分析未显示 RPMI8226、模拟对照和 D1 转染子之间存在任何差异。 D1转染子中S期细胞数量增加，而G(0)/G(1)-和G(2)/M期细胞数量减少，这表明cyclin D1转染导致S期细胞延长。在 t(11;14)(q13;q32) 易位患者的骨髓瘤细胞中也检测到 G(2)/M 期细胞数量减少。蛋白质印迹分析显示，D1 转染子中视网膜母细胞瘤 (Rb) 蛋白的过度磷酸化形式有所增加；然而，p53、p16、Bax、Bad、Bcl-2和Mcl-1的表达没有显着变化。与 RPMI8226 和模拟对照相比，抗骨髓瘤药物（美法仑、地塞米松、硼替佐米和免疫调节化合物）治疗通过激活 caspase-8 和 -9 更早诱导 D1 转染子发生细胞凋亡。然而。我们无法检测到细胞周期蛋白 D1 表达与 VAD 和硼替佐米治疗反应之间的关系。因此，我们假设抗骨髓瘤药物的高敏感性取决于 S 期的持续时间，但临床反应可能取决于细胞周期蛋白 D1 过度表达的骨髓瘤细胞的数量。
We established a myeloma cell line (RPMI8226) with cyclin D1 overexpression in which the transfected cyclin D1 gene was stably expressed. D1 transfectants showed down-regulation of cyclin D2. Cell proliferation analysis did not show any differences among RPMI8226, mock control, and D1 transfectants. The number of S-phase cells increased while the number of G(0)/G(1)- and G(2)/M-phase cells decreased in D1 transfectants, which indicates a prolonged S-phase caused by cyclin D1 transfection. A decreased number of G(2)/M-phase cells was also detected in myeloma cells of patients with translocation t(11;14)(q13;q32). Western blot analysis revealed an increase in the hyperphosphorylated form of retinoblastoma (Rb) protein in D1 transfectants; however, the expression of p53, p16, Bax, Bad, Bcl-2, and Mcl-1 did not significantly change. Treatment with anti-myeloma drugs (melphalan, dexamethasone, bortezomib and immunomodulatory compounds) induced apoptosis earlier in D1 transfectants compared with RPMI8226 and mock control via the activation of both caspase-8 and -9. However. we could not detect a relationship between cyclin D1 expression and the response to treatment with VAD and bortezomib. Therefore, we assume that high sensitivity to anti-myeloma drugs depends on the duration of the S-phase, but a clinical response might depend on the number of myeloma cells with cyclin D1 overexpression.