Knockdown of ribonuclease inhibitor expression with siRNA in non-invasive bladder cancer cell line BIU-87 promotes growth and metastasis potentials
Knockdown of ribonuclease inhibitor expression with siRNA in non-invasive bladder cancer cell line BIU-87 promotes growth and metastasis potentials
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在非侵袭性膀胱癌细胞系 BIU-87 中用 siRNA 敲低核糖核酸酶抑制剂表达可促进生长和转移潜力
DOI：
10.1007/s11010-010-0663-7
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发表时间：
2011-03-01
影响因子：
4.3
通讯作者：
Rong, Jiang
中科院分区：
文献类型：
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作者：
Chen, Junxia;Ou-Yang, Xi;Rong, Jiang
人核糖核酸酶抑制因子（RI）是一种细胞质酸性蛋白。RI几乎完全由富含亮氨酸的重复序列组成，除了抑制RNA酶A和血管生成素活性外，还可能与其他结构相似的蛋白质一样参与一些未知的生物学功能。我们前期的实验表明，上调RI可能有效抑制某些肿瘤的生长和转移。然而，RI下调对肿瘤的影响至今未见报道，RI抗肿瘤的机制尚未完全阐明。本研究利用质粒载体构建了RI的高效RNA干扰物，经RT-PCR、Western blot和免疫细胞化学鉴定后，转染非侵袭性膀胱癌BIU-87细胞。体外实验表明，RI基因敲低可明显改变BIU-87细胞的形态，使细胞微丝重排，板状伪足延长，并可促进细胞增殖，增加细胞的迁移、侵袭能力，增加细胞内基质金属蛋白酶的水平，降低细胞的黏附能力。转染RI siRNA的BIU-87细胞注射BALB/C裸鼠后，肿瘤重量明显增加，微血管密度增加，nm 23-H1和E-Cadherin表达明显降低。综上所述，这些实验表明，RI的敲低可以促进BIU-87细胞的生长和转移潜力。我们的研究结果揭示了新的机制，RI的抗肿瘤作用，也参与了抑制生长和转移，除了抗血管生成。结果表明，RI可能是膀胱癌治疗的靶蛋白，具有重要的生物学意义。
Human ribonuclease inhibitor (RI) is a cytoplasmic acidic protein. RI is constructed almost entirely of leucine-rich repeats, which might be involved in some unknown biological functions like other structurally similar proteins besides inhibiting RNase A and angiogenin activities. Our previous experiments demonstrated that up-regulating RI might effectively inhibit some tumor growth and metastasis. However, the down-regulating RI influence on the tumor does not have any report until now, the mechanisms underlying antitumor of RI have not been fully understood. In this study, the efficient RNA interferences of RI were constructed using a plasmid vector and identified with RT-PCR, Western blot and Immunocytochemistry, then were transfected into non-invasive bladder cancer BIU-87 cells. We demonstrated that knockdown RI expression in BIU-87 cells could obviously change the cell morphology, rearrange the microfilaments and extend the lamellipodia, as well as enhance proliferation, increase migration, invasion and matrix metalloprotease level, and also reduce adhesion in vitro. BALB/C nude mice that were injected with the BIU-87 cells transfected RI siRNA showed a significant facilitation of the tumor with heavier tumor weight, higher density of microvessels, lower nm23-H1 and E-Cadherin expressions than those in the control group. Taken together, these experiments suggest that knockdown of RI could promote growth and metastasis potentials of BIU-87 cells. Our present findings reveal the novel mechanism that anti-tumor effect of RI is also involved in suppressing growth and metastasis, besides antiangiogenesis. The results show that RI may be a therapeutic target protein for bladder cancer and may be of biological importance.