中文摘要：

目的 研究3′-磷酸腺苷-5′-磷酰硫酸转运体1（adenosine-3-phospho-5-phosphosulfate transporter 1，PAPST1）在髓母细胞瘤中的表达情况，探讨其对髓母细胞瘤细胞系增殖活性的影响。 方法 采用qRT-PCR法检测25例髓母细胞瘤标本、1例原代培养髓母细胞瘤细胞、3例髓母细胞瘤细胞系PAPST1表达，并与正常小脑组织比较，利用免疫组织化学检测PAPST1在髓母细胞瘤中的表达分布，采用PAPST1 siRNA 处理髓母细胞瘤细胞系DAOY，利用qRT-PCR、Western blot法检测PAPST1表达变化，CCK-8法检测处理后的DAOY细胞系增殖活性。 结果 与正常小脑组织相比,PAPST1在18/25 （72%）的髓母细胞瘤标本及DAOY、ONS-76细胞系中呈2倍以上的高表达，免疫组化显示PAPST1定位于细胞质中,且染色明显强于正常小脑组织，PAPST1 siRNA在mRNA及蛋白的水平明显干扰了PAPST1的表达（P〈0.05），DAOY细胞的增殖活性受到明显抑制（P〈0.05）。 结论 PAPST1在髓母细胞瘤中有广泛的高表达，下调PAPST1的表达可以降低髓母细胞瘤细胞的增殖活性。

英文摘要：

Objective To investigate the expression pattern of adenosine-3-phospho-5-phosphosulfate transporter 1 （PAPST1） in medulloblastoma （MB）, and its role in proliferation of MB cells. Methods The expression of PAPST1 was examined by qRT-PCR in 25 MB tumor samples, 1 primary cultured MB cells （pri-MB）, 3 MB cell lines （DAOY, D341 and ONS-76） and the normal cerebellums. The distribution of PAPST1 protein was stained by immunohistochemical technique. siRNA technique was applied in DAOY cells to knockdown the expression PAPST1 at mRNA and protein levels, which was confirmed by qRT-PCR and Western blot analysis. CCK-8 assay was carried out to determine the proliferation activity of DAOY cells after PAPST1 knockdown. Results qRT-PCR revealed 〉2 folds up-regulation in 18/25 （72%） MB samples and in DAOY and ONS-76 MB cell lines, compared with normal human cerebellum. Immunohistochemical staining revealed that the PAPST1 protein was located in the cytoplasm, and the stronger expression of PAPST1 in MB tumor tissues. The results of qRT-PCR and Western blotting showed a significant knockdown of PAPST1 at mRNA and protein levels in DAOY MB cells, and the CCK-8 assay revealed that cell proliferation was inhibited by siRNA technique. Conclusion High expression of PAPST1 is a common event in MB, and down-regulation of PAPST1 can induce proliferation inhibition in MB cells.