Wang Xiaobo, Pan Jingxuan, Li Juan
Department of Hematology, The First Affiliated Hospital, Sun Yat‑sen University, Guangzhou, Guangdong 510080, P.R. China.
Mol Med Rep. 2015 Aug;12(2):2056-62. doi: 10.3892/mmr.2015.3656. Epub 2015 Apr 22.
The present study investigated the differential expression of cytokine-induced apoptosis inhibitor 1 (CIAPIN1) in human multiple myeloma (MM) bone marrow tissue and adjacent healthy bone marrow tissue. In addition, the effect of a transduced CIAPIN1 gene on the growth of the RPMI-8226 human MM cell line was investigated. CIAPIN1 protein expression was detected in 32 samples of paraffin-embedded MM and adjacent healthy bone marrow tissue using immunohistochemistry. The CIAPIN1 gene (Ad-CIAPIN1, small interfering RNA) was inserted into a lentiviral vector and transfected into the RPMI-8226 human MM cell line. The expression of target proteins CIAPIN1 and insulin-like growth factor 1 U (IGF-1), cell cycle-regulatory proteins and functional proteins was detected using western blotting. MTT and soft agar colony formation assays were conducted, and cellular tumorigenicity in nude mice was assessed, in order to investigate the proliferative capacity of cells in vitro and in vivo. Flow cytometry was applied in order to analyze changes in the cell cycle and cell apoptosis. CIAPIN1 expression was significantly reduced in cells from the 32 MM samples compared with those from healthy bone marrow (P<0.05). Upregulation of CIAPIN1, following transduction by lentiviral vectors, caused cells to arrest in G1/S phase of the cell cycle and significantly inhibited the growth of the RPMI-8226 MM cell line in vitro and in vivo. CIAPIN1 was shown to inhibit cell growth. Specifically, it inhibited cyclin-dependent kinase 2, cyclin-dependent kinase 4 and insulin-like growth factor-1. Increased expression of CIAPIN1 also led to an increase in the levels of p27 and Rb, an effect that may have been achieved via regulation of cell cycle proteins and functional proteins. The results of the present study suggest that downregulation of the CIAPIN1 gene in MM cells may be associated with the development of this disease. CIAPIN1 transfection in RPMI-8226 cells significantly inhibited the growth of tumor cells, suggesting that the CIAPIN1 gene is a potential tumor suppressor.
本研究调查了细胞因子诱导的凋亡抑制因子1（CIAPIN1）在人多发性骨髓瘤（MM）骨髓组织及相邻健康骨髓组织中的差异表达。此外，还研究了转导CIAPIN1基因对RPMI-8226人MM细胞系生长的影响。采用免疫组织化学法检测了32例石蜡包埋的MM及相邻健康骨髓组织样本中CIAPIN1蛋白的表达。将CIAPIN1基因（腺病毒载体CIAPIN1、小干扰RNA）插入慢病毒载体并转染至RPMI-8226人MM细胞系。采用蛋白质免疫印迹法检测靶蛋白CIAPIN1和胰岛素样生长因子1U（IGF-1）、细胞周期调节蛋白和功能蛋白的表达。进行MTT和软琼脂集落形成试验，并评估裸鼠体内的细胞致瘤性，以研究细胞在体外和体内的增殖能力。应用流式细胞术分析细胞周期和细胞凋亡的变化。与健康骨髓细胞相比，32例MM样本细胞中的CIAPIN1表达显著降低（P<0.05）。慢病毒载体转导后CIAPIN1上调，使细胞停滞于细胞周期的G1/S期，并显著抑制RPMI-8226 MM细胞系在体外和体内的生长。结果表明CIAPIN1可抑制细胞生长。具体而言，它抑制细胞周期蛋白依赖性激酶2、细胞周期蛋白依赖性激酶4和胰岛素样生长因子-1。CIAPIN1表达增加还导致p27和Rb水平升高，这一效应可能是通过调节细胞周期蛋白和功能蛋白实现的。本研究结果提示，MM细胞中CIAPIN1基因的下调可能与该疾病的发生发展有关。CIAPIN1转染RPMI-8226细胞可显著抑制肿瘤细胞生长，提示CIAPIN1基因是一种潜在的肿瘤抑制基因。
