Shear stress activates ATOH8 via autocrine VEGF promoting glycolysis dependent-survival of colorectal cancer cells in the circulation
Shear stress activates ATOH8 via autocrine VEGF promoting glycolysis dependent-survival of colorectal cancer cells in the circulation
复制标题
剪切应力通过自分泌 VEGF 激活 ATOH8，促进循环中结直肠癌细胞的糖酵解依赖性存活。
DOI：
10.1186/s13046-020-1533-0
复制
发表时间：
2020-01-30
影响因子：
11.3
通讯作者：
Shi, Min
中科院分区：
文献类型：
--
作者：
Huang, Qiong;Li, Shaowei;Shi, Min
背景转移和复发是导致结直肠癌(CRC)死亡的主要原因，其中循环肿瘤细胞(CTCs)起着重要作用。启动转移的CTCs在失巢、免疫攻击和重要的剪切力作用下维持血管内存活；然而，其潜在的机制仍然知之甚少。方法针对血液中CTCs稀少的特点，根据前人的研究，将悬浮的结直肠癌细胞注入循环层流切应力(LSS)。然后，我们对这些具有CK8+/CD45-/DAPI+表型的悬浮细胞进行检测，并将其命名为模拟循环肿瘤细胞(m-CTCs)，为后续CTCs的相关研究做准备。采用定量聚合酶链式反应、免疫印迹和免疫荧光等方法分析对LSS刺激敏感的m-CTCs基因表达变化。此外，我们通过荧光原位杂交和流式细胞术检测了156例结直肠癌患者和小鼠的CTCs中无性型bHLH8转录因子(ATOH8)的表达。用糖酵解试验、活/死细胞活力试验、失巢凋亡试验和免疫组织化学方法检测ATOH8的促代谢和促生存功能。进一步探讨了ATOH8促进m-CTC存活的具体机制。结果m-CTCs通过激活流体机械传感器ATOH8的表达对LSS产生积极反应，ATOH8在血管内存活和代谢可塑性中起执行作用。具体地说，ATOH8是通过LSS诱导的VEGFR2/AKT信号通路的激活而上调的。ATOH8然后转录激活HK2介导的糖酵解，从而促进循环中结直肠癌细胞的血管内存活。结论本研究阐明了LSS触发的VEGF-VEGFR2-AKT-ATOH8信号轴介导m-CTCs存活的新机制，为预防和治疗结直肠癌血行转移提供了新的靶点。
Background Metastasis and recurrence, wherein circulating tumour cells (CTCs) play an important role, are the leading causes of death in colorectal cancer (CRC). Metastasis-initiating CTCs manage to maintain intravascular survival under anoikis, immune attack, and importantly shear stress; however, the underlying mechanisms remain poorly understood. Methods In view of the scarcity of CTCs in the bloodstream, suspended colorectal cancer cells were flowed into the cyclic laminar shear stress (LSS) according to previous studies. Then, we detected these suspended cells with a CK8+/CD45-/DAPI+ phenotype and named them mimic circulating tumour cells (m-CTCs) for subsequent CTCs related researches. Quantitative polymerase chain reaction, western blotting, and immunofluorescence were utilised to analyse gene expression change of m-CTCs sensitive to LSS stimulation. Additionally, we examined atonal bHLH transcription factor 8 (ATOH8) expressions in CTCs among 156 CRC patients and mice by fluorescence in situ hybridisation and flow cytometry. The pro-metabolic and pro-survival functions of ATOH8 were determined by glycolysis assay, live/dead cell vitality assay, anoikis assay, and immunohistochemistry. Further, the concrete up-and-down mechanisms of m-CTC survival promotion by ATOH8 were explored. Results The m-CTCs actively responded to LSS by triggering the expression of ATOH8, a fluid mechanosensor, with executive roles in intravascular survival and metabolism plasticity. Specifically, ATOH8 was upregulated via activation of VEGFR2/AKT signalling pathway mediated by LSS induced VEGF release. ATOH8 then transcriptionally activated HK2-mediated glycolysis, thus promoting the intravascular survival of colorectal cancer cells in the circulation. Conclusions This study elucidates a novel mechanism that an LSS triggered VEGF-VEGFR2-AKT-ATOH8 signal axis mediates m-CTCs survival, thus providing a potential target for the prevention and treatment of hematogenous metastasis in CRC.