Background & Aims

Cytokinesis can fail during normal postnatal liver development, leading to polyploid hepatocytes. We investigated whether inhibiting cytokinesis in the liver slows tumor growth without compromising the health of normal hepatocytes. We inhibited cytokinesis in cancer cells by knocking down ANLN, a cytoskeletal scaffolding protein that regulates cytokinesis and might promote tumorigenesis, in mice with liver disease.

Methods

We analyzed clinical and gene expression data from The Cancer Genome Atlas, Oncomine, PrognoScan, and a hepatocellular carcinoma (HCC) tissue microarray. We knocked down ANLN with small interfering RNAs (siRNAs) in H2.35 liver cells and performed image analyses of cells undergoing cytokinesis. siRNAs were delivered to LAP-MYC mice, which develop hepatoblastoma, using lipid nanoparticles. H2.35 cells with knockdown of ANLN or control cells were injected into FRG mice, which develop chronic liver damage, and tumor growth was monitored. We also developed mice with inducible expression of transgenes encoding small hairpin RNAs (shRNAs) against Anln messenger RNA and studied liver tumorigenesis after administration of diethylnitrosamine and carbon tetrachloride. siRNAs against Anln messenger RNA were conjugated to N-acetylgalactosamine to reduce toxicity and increase hepatocyte tropism; their effects were studied in mouse models of liver cancer and regeneration.

Results

Levels of ANLN messenger RNA were increased in human HCC tissues compared to non-tumor liver tissues. siRNA knockdown of ANLN blocked cytokinesis in H2.35 liver cells. Administration of siRNA against ANLN increased survival times of LAP-MYC mice, compared to mice given a control siRNA. H2.35 liver cells with shRNA knockdown of ANLN formed tumors more slowly in FRG mice than control H2.35 cells. Mice with inducible expression of shRNAs against Anln mRNA developed fewer liver tumors after administration of diethylnitrosamine and carbon tetrachloride than control mice. Knockdown of ANLN did not affect liver regeneration after acute and chronic liver injuries.

Conclusions

Knockdown of ANLN in liver cells blocks cytokinesis and inhibits development of liver tumors in mice. Agents that inhibit ANLN in the liver might be effective for prevention or treatment of HCC.

中文翻译：

---

击倒Anillin肌动蛋白结合蛋白可阻断肝细胞的胞质分裂，并在不影响再生的情况下降低小鼠肝肿瘤的发展

背景与目标

在正常的产后肝脏发育过程中，胞质分裂可能会失败，从而导致多倍体肝细胞。我们调查了抑制肝脏中的胞质分裂是否会减慢肿瘤的生长而不损害正常肝细胞的健康。我们通过敲低患有肝病的小鼠ANLN（一种调节细胞分裂并可能促进肿瘤发生的细胞骨架支架蛋白）来抑制癌细胞的细胞分裂。

方法

我们分析了来自癌症基因组图谱，Oncomine，PrognoScan和肝细胞癌（HCC）组织微阵列的临床和基因表达数据。我们用H2.35肝细胞中的小干扰RNA（siRNA）敲低了ANLN，并对细胞进行胞质分裂的细胞进行了图像分析。siRNA使用脂质纳米颗粒递送至发展成肝母细胞瘤的LAP-MYC小鼠。将具有ANLN基因敲低的H2.35细胞或对照细胞注射到FRG小鼠中，使其发展为慢性肝损伤，并监测肿瘤的生长。我们还开发了可诱导表达编码抗Anln Messenger的小发夹RNA（shRNA）的转基因的小鼠，并研究了在施用二乙基亚硝胺和四氯化碳后肝脏的肿瘤发生情况。抗Anln的siRNA将信使RNA与N-乙酰半乳糖胺缀合以减少毒性并增加肝细胞向性。在肝癌和再生小鼠模型中研究了它们的作用。

结果

与非肿瘤肝组织相比，人肝癌组织中ANLN信使RNA的水平增加。siRNA敲低ANLN阻断了H2.35肝细胞的胞质分裂。与给予对照siRNA的小鼠相比，针对ANLN施用siRNA可以增加LAP-MYC小鼠的存活时间。具有HNL敲低ANLN的H2.35肝细胞在FRG小鼠中形成肿瘤的速度比对照H2.35细胞慢。与对照小鼠相比，给予二乙基亚硝胺和四氯化碳后，具有针对Anln mRNA的shRNA诱导表达的小鼠出现的肝脏肿瘤更少。急性和慢性肝损伤后，击倒ANLN不会影响肝再生。

结论

剔除肝细胞中的ANLN会阻止细胞分裂并抑制小鼠肝肿瘤的发展。抑制肝脏中ANLN的药物可能有效预防或治疗HCC。