Objective: To investigate the effect of UCHL5 on proliferation and apoptosis of breast cancer cells. Methods: SW527 cells were infected with lentiviral vector carrying short hairpin RNA to delete the expression of UCHL5. 3-(4, 5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay was used to examine cell proliferation, and subcutaneous transplantation experiments were performed to detect tumor growth. Cell apoptosis was detected using Annexin V/ Propidium iodide (PI) double staining. The correlation between UCHL5 expression and the expressions of proliferation and apoptosis associated genes was analyzed using TCGA breast invasive carcinoma data set. The relationship between UCHL5 expression and breast cancer patients'survival was analyzed using Kaplan-Meier Plotter online tool. Results: After knockdown of UCHL5, A values of SW527 cells on day 2 and day 4 were 0.822±0.017 and 1.045±0.023, respectively, which were significantly lower than 0.976±0.016 and 1.284±0.025 of control cells on day 2 and day 4 (P<0.001). In vivo xenografted mouse model, the volume in UCHL5-suppressed group was (166.90±75.05) mm(3,) significantly smaller than (329.80±35.84) mm(3) in control group (P=0.029). Flow cytometry analysis showed the apoptotic rate of SW527 cells was (8.60±1.13)% after knockdown of UCHL5, significantly higher than (2.95±0.07)% of control group (P=0.020). TCGA database analysis showed that the expression of UCHL5 was positively correlated with the expressions of genes related to cell proliferation, in paralled with the increased expression of UCHL5, the expression of the pro-apoptosis associated genes was decreased. Kaplan-Meier Plotter analysis demonstrated that the overall survival and relapse-free survival of breast cancer patients with high expression of UCHL5 were much shorter (all P<0.001). Conclusions: Down-regulation of UCHL5 inhibits the proliferation and tumor formation and promotes apoptosis of SW527 cells. High expression of UCHL5 may predict poor prognosis of breast cancer patients.
目的： 探讨泛素羧基末端水解酶L5(UCHL5)在乳腺癌细胞增殖和凋亡过程中的作用。 方法： 以慢病毒介导的shRNA系统敲低SW527细胞中UCHL5基因的表达，采用MTS法检测UCHL5表达改变对SW527细胞增殖的影响，采用裸鼠皮下成瘤实验检测UCHL5对SW527细胞裸鼠体内成瘤能力的影响，采用annexinV－PI双染法检测SW527细胞的凋亡。以TCGA浸润性乳腺癌数据分析UCHL5的表达与乳腺癌增殖凋亡相关基因表达的相关性。以Kaplan Meier－plotter在线数据库分析UCHL5表达与乳腺癌患者预后的关系。 结果： 敲低UCHL5的表达后，SW527细胞第2、4天的A值分别为0.822±0.017和1.045±0.023，均明显低于对照组细胞在第2、4天的A值(分别为0.976±0.016和1.284±0.025，P<0.001)。在裸鼠成瘤实验中，UCHL5敲低后SW527细胞的成瘤体积为(166.90±75.05)mm(3)，明显小于对照组细胞的成瘤体积[(329.80±35.84)mm(3)，P＝0.029]。流式细胞术检测结果显示，敲低UCHL5的表达后，SW527细胞的凋亡比例为(8.60±1.13)%，明显高于对照组[(2.95±0.07)%，P＝0.020]。TCGA数据库分析表明，UCHL5的表达与细胞增殖相关基因的表达呈正相关，且随着UCHL5表达升高，促凋亡相关基因表达下降。Kaplan Meier－plotter分析显示，UCHL5高表达乳腺癌患者的总生存时间和无复发生存时间均明显短于UCHL5低表达患者(均P<0.001)。 结论： 敲低UCHL5的表达可抑制SW527细胞的增殖和裸鼠皮下成瘤能力，促进细胞凋亡，并且UCHL5的高表达预示着乳腺癌患者的不良预后。.
Keywords: Apoptosis; Breast neoplasms; Cell proliferation; Prognosis; SW527 cell; UCHL5.