HOXD3 Plays a Critical Role in Breast Cancer Sternness and Drug Resistance
HOXD3 Plays a Critical Role in Breast Cancer Sternness and Drug Resistance
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HOXD3 在乳腺癌恶化和耐药性中发挥关键作用
DOI：
10.1159/000489249
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发表时间：
2018-01-01
影响因子：
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通讯作者：
Pang, Da
中科院分区：
文献类型：
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作者：
Zhang, Yue;Zhang, Qingyuan;Pang, Da
背景/目标：同源异型盒D3（HOXD 3）是同源异型盒基因家族的成员，其主要已知在所有多细胞生物中的形态发生的转录调控。在这项研究中，我们试图探索HOXD 3在乳腺癌细胞的干细胞样能力或干细胞性和耐药性中的作用。方法：采用RT-PCR和免疫组织化学方法检测HOXD 3在临床乳腺组织中的表达。用RT-PCR和Western blot检测乳腺癌细胞系中HOXD 3的表达。MTT法和集落形成实验显示，乳腺癌细胞的耐药能力明显增强。我们使用细胞荧光染色、RT-PCR和蛋白质印迹检测干细胞标记物表达。最后，通过FOPflash荧光素酶测定分析wnt信号传导的活性。对wnt信号下游基因进行RT-PCR和western blot检测。结果：我们证明HOXD 3在乳腺癌组织中过表达，与正常乳腺组织相比。HOXD 3过表达增强乳腺癌细胞耐药性此外，HOXD 3在相同细胞系中的上调增加了球体形成以及干细胞生物标志物的表达水平，表明HOXD 3确实增加了乳腺癌细胞的干细胞性。因为我们先前已经表明HOXD 3表达与乳腺癌患者中的整合素β 3表达密切相关，所以我们假设HOXD 3可能通过整合素β 3调节乳腺癌细胞的干性和耐药性。细胞活力测定表明，整合素β 3敲低增加了细胞活力，HOXD 3不能恢复癌细胞的干性或耐药性。鉴于整合素β 3与Wnt/β-连环蛋白信号传导的关系，我们确定HOXD 3是否通过Wnt/β-连环蛋白信号传导调节整合素β 3活性。我们发现，尽管HOXD 3增加了Wnt/β-连环蛋白下游基因的表达，但它并没有恢复Wnt/β-连环蛋白信号传导活性，这在整合素β 3敲低的乳腺癌细胞中受到抑制。结论：我们证明HOXD 3通过整合素β 3介导的Wnt/β-连环蛋白信号传导在乳腺癌的干性和耐药性中起关键作用。我们的研究结果打开了通过设计克服癌细胞干性和耐药性障碍的靶向分子疗法来改善乳腺癌患者当前护理标准的可能性。(C)2018作者（S）由S发布。Karger AG，巴塞尔。
Background/Aims: Homeobox D3 (HOXD3) is a member of the homeobox family of genes that is known primarily for its transcriptional regulation of morphogenesis in all multicellular organisms. In this study, we sought to explore the role that HOXD3 plays in the stem-like capacity, or sternness, and drug resistance of breast cancer cells. Methods: Expression of HOXD3 in clinical breast samples were examined by RT-PCR and immunohistochemistry. HOXD3 expression in breast cancer cell lines were analyzed by RT-PCR and western blot. Ability of drug resistance in breast cancer cells were elevated by MTT cell viability and colony formation assays. We examined sternness using cell fluorescent staining, RT-PCR and western blot for stem cell marker expression. Finally, activity of wnt signaling was analyzed by FOPflash luciferase assays. RT-PCR and western blot were performed for downstream genes of wnt signaling. Results: We demonstrated that HOXD3 is overexpressed in breast cancer tissue as compared to normal breast tissue. HOXD3 overexpression enhances breast cancer cell drug resistance. Furthermore, HOXD3 upregulation in the same cell lines increased sphere formation as well as the expression levels of stern cell biomarkers, suggesting that HOXD3 does indeed increase breast cancer cell sternness. Because we had previously shown that HOXD3 expression is closely associated with integrin beta 3 expression in breast cancer patients, we hypothesized that HOXD3 may regulate breast cancer cell sternness and drug resistance through integrin beta 3. Cell viability assays showed that integrin beta 3 knockdown increased cell viability and that HOXD3 could not restore cancer cell sternness or drug resistance. Given integrin beta 3's relationship with Wnt/beta-catenin signaling, we determine whether HOXD3 regulates integrin beta 3 activity through Wnt/beta-catenin signaling. We found that, even though HOXD3 increased the expression of Wnt/beta-catenin downstream genes, it did not restore Wnt/beta-catenin signaling activity, which was inhibited in integrin beta 3 knockdown breast cancer cells. Conclusion: We demonstrate that HOXD3 plays a critical role in breast cancer sternness and drug resistance via integrin beta 3-mediatedWnt/beta-catenin signaling. Our findings open the possibility for improving the current standard of care for breast cancer patients by designing targeted molecular therapies that overcome the barriers of cancer cell sternness and drug resistance. (C) 2018 The Author(s) Published by S. Karger AG, Basel.