RAB5C, a new mRNA binding target of HuR, regulates breast cancer cell proliferation
RAB5C, a new mRNA binding target of HuR, regulates breast cancer cell proliferation
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DOI：
10.1002/cbin.11969
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发表时间：
2022-12
影响因子：
3.9
通讯作者：
Zhenzhen Wang;Fang Li;Huahua Zhang;Xiaoyi Hu;Yanke Chen;Chen Huang
中科院分区：
文献类型：
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作者：
Zhenzhen Wang;Fang Li;Huahua Zhang;Xiaoyi Hu;Yanke Chen;Chen Huang
由RNA结合蛋白（RBP）介导的基因表达的转录后控制对于决定肿瘤细胞的命运至关重要。HuR是在各种癌症类型中表达增加的RBP。本研究旨在阐明HuR通过诱导RAB 5C表达促进乳腺癌细胞增殖的调控机制。首先，我们通过免疫组织化学、qRT-PCR和western blot分析了HuR和RAB 5C在BC组织和细胞系中的表达水平。接下来，为了进一步研究HuR对RAB 5C表达的影响，我们使用短发夹RNA（shRNAs）来沉默BC细胞系MCF 7和MDA-MB-231中的内源性HuR表达。RNA免疫沉淀法证实了RAB 5C mRNA与HuR的结合位点。最后，使用流式细胞术、集落形成和MTT测定来研究RAB 5C的功能。我们发现，HuR和RAB 5C的表达在BC组织和MCF-7和MDA-MB 231细胞系中显著上调。重要的是，RAB 5C mRNA的稳定性通过HuR与其3′UTR的结合而增加。使用shRNA抑制HuR表达降低了RAB 5C mRNA，表明HuR在调节RAB 5C表达水平中起作用。此外，RAB 5C表达的抑制降低了BC细胞的生长。这些结果表明，在BC细胞中，RAB 5C作为癌基因起作用，HuR通过促进RAB 5C表达而促进BC细胞存活。我们的研究结果表明，HuR和RAB 5C在BC细胞存活中起重要作用。
The posttranscriptional control of gene expression mediated by RNA‐binding proteins (RBPs) is essential to determine tumor cell fate. HuR is an RBP with increased expression in various cancer types. This study aimed to clarify the regulatory mechanism of HuR's contribution to breast cancer (BC) cell proliferation by inducing RAB5C expression. First, we analyzed the expression level of HuR and RAB5C in BC tissues and cell lines by immunohistochemistry, qRT‐PCR, and western blot. Next, to further investigate the effect of HuR on RAB5C expression, we used short hairpin RNAs (shRNAs) to silence endogenous HuR expression in BC cell lines MCF7 and MDA‐MB‐231. The binding site of RAB5C mRNA and HuR was confirmed by RNA immunoprecipitation. Finally, the function of RAB5C was investigated using flow cytometry, colony formation, and MTT assays. We found that the expression of HuR and RAB5C was significantly upregulated in BC tissues and MCF‐7 and MDA‐MB231 cell lines. Importantly, RAB5C mRNA stability was increased through binding of HuR to its 3′UTR. Inhibition of HuR expression using shRNA decreased RAB5C mRNA, suggesting that HuR plays a role in regulating RAB5C expression level. In addition, suppression of RAB5C expression reduced BC cell growth. These results suggest RAB5C functions as an oncogene in BC cells, HuR promoted BC cell survival by facilitating RAB5C expression. Our findings suggest that HuR and RAB5C play important roles in BC cell survival.