目的：通过建立稳定过表达溶酶体相关穿膜蛋白5(lysosomal associated protein transmembrane 5, Laptm5) 3′不翻译区（3′UTR）的B细胞淋巴瘤38B9细胞株，探讨Laptm5 3′UTR对小鼠B细胞淋巴瘤38B9细胞株增殖、凋亡的影响。方法： 荧光定量PCR及Western blotting检测小鼠B细胞及38B9细胞中Laptm5miRNA及其蛋白质的表达水平；将小鼠Laptm5 3′UTR 及其含有的microRNA结合位点突变的突变型基因片段构建入逆转录病毒表达载体pMSCV-PIG，包装成逆转录病毒，感染小鼠B细胞淋巴瘤细胞38B9，流式细胞术检测逆转录病毒感染率，细胞计数法及流式细胞术观察Laptm5 3′UTR或其突变型过表达后389B9细胞的增殖、凋亡情况。结果：相比小鼠B细胞，B细胞淋巴瘤细胞中Laptm5的miRNA及蛋白均显著降低（P<0.01）。成功获得稳定过表达Laptm5 3′UTR（突变型）的38B9细胞株。Laptm5 3′UTR细胞株比Laptm5 3′UTR突变型过表达细胞株的增殖能力显著减慢，凋亡率显著增加\[（7.87±1.08)% vs (0.45±0.07)%, P<0.01\]。结论： 小鼠Laptm5 3′UTR具有抑制B细胞淋巴瘤增殖、促进其凋亡的作用，该作用可能与其影响相关microRNA的调控有关。

Objective:To explore effect of lysosomal associated protein transmembrane 5 (Laptm5) 3′untranslated region (3′UTR) on proliferation and apoptosis of mouse B-cell lymphoma 38B9 line cell, by means of establishing B-cell lymphoma cell line with stable overexpression of Laptm5 3′UTR. Methods:Expressions of Laptm5 miRNA and its protein in normal mouse B cell and the mouse B-cell lymphoma 38B9 line cell were respectively examined by Western blotting and fluorescence quantitative PCR. A mouse Laptm5 3′UTR and Laptm5 3′UTR mutation gene fragment containing mutated miRNA 17-3p binding sites were inserted into retrovirus expression vector pMSCV-PIG. The retrovirus was constructed and the mouse B-cell lymphoma 38B9 line cell was infected by the retrovirus. Infection rate of the retrovirus was detected by flow cytometry assay. Cell counting method and flow cytometry assay observed proliferation and apoptosis of the 38B9 cells with Laptm5 3′UTR or mutated overexpression of Laptm5 3′UTR respectively. Results: Expressions of Laptm5 miRNA and its protein in the B-cell lymphoma cell all were more significantly reduced than those in the mouse B cell (all P<0.01). The 38B9 line cell with stable overespression of Laptm5 3′UTR (mutated Laptm5 3′UTR) was succesfully constructed. Proliferation ability of the 38B9 cell with Laptm5 3′UTR was more obviously decreased than that in the 38B9 cell with the mutated Laptm5 3′UTR and apoptosis of the 38B9 cell with Laptm5 3′UTR was more significantly increased than that in the 38B9 cell with the mutated Laptm5 3′UTR （\[7.87±1.08\]% vs \[0.45±0.07\]%, P<0.01). Conclusion: Mouse Laptm5 3′UTR might have functions of inhibiting growth of B-cell lymphoma and promoting its apoptosis. The functions could be associated with regulating its effected-miRNA.

国家自然科学基金资助项目（No. 81302041）；江苏省自然科学基金资助项目（No. BK20130454）