微小RNA-34a 通过靶向CD44调节膀胱癌细胞J82周期

目的观察微小RNA-34a（miR-34a）对膀胱癌细胞J82周期的影响，并探索其中的机制。方法于J82中转染miR-34a前体
或miR-34a 抑制物并验证转染效率，结合此前研究报道和生物信息学预测miR-34a 的靶点，后通过荧光素酶报告实验验证
miR-34a靶标基因CD44，通过Western blot和实时定量PCR方法检测CD44及其周期相关蛋白及信使RNA表达水平的变化，利
用流式细胞仪检测膀胱癌细胞J82周期的变化。结果miR-34a在膀胱癌细胞J82和组织中表达下调，转染miR-34a 前体和抑制
物后，获得满意的转染效果；双荧光素酶报告实验证实miR-34a对CD44的3’UTR活性显著调节，并伴随相关周期相关因子表达
水平变化，同时观测到其对膀胱癌细胞J82 周期的影响。miR-34a mimics 明显降低膀胱癌细胞J82 中CD44 的表达，miR-34a
inhibitor 明显上调膀胱癌细胞J82 中CD44 的表达；CD44 可以部分回复mir-34a 对膀胱癌细胞J82 周期的影响。结论微小
RNA-34a 通过直接靶向CD44调节膀胱癌细胞J82周期的变化。

MicroRNA-34a regulates cell cycle by targeting CD44 in human bladder carcinoma cells

Objective To investigate the role of microRNA-34a (miR-34a) in regulating the cell cycles of bladder cancer cell line
J82 and explore the underlying mechanism. Methods J82 cells were transfected with a miR-34a mimic or an inhibitor to induce
miR-34a overexpression or silencing. The RNA level of miR-34a in the transfected cells was detected by real-time PCR, and
CD44 expressions at the mRNA and protein levels were detected by real-time PCR and Western blotting. Luciferase reporter
assay was used to detect the activation of 3’UTR of CD44, and flow cytometry was performed to analyze the cell cycle changes.
Results The expression level of miR-34a was significantly increased and CD44 expression significantly lowered in cells
transfected with miR-34a mimic; miR-34a inhibitor transfection caused reverse effects on miR-34a and CD44 expressions.
MiR-34a mimics downregulated while miR-34a inhibitor enhanced the activation of 3’UTR of CD44 with corresponding
changes in the expressions of some cell cycle-related proteins. MiR-34a mimics and miR-34a inhibitor induced opposite
changes in J82 cell cycle, which were partly reversed by CD44. Conclusion MiRNA-34a regulates cell cycles by targeting CD44
in human bladder carcinoma cell line J82.