Huang Ai-Hua, Wang Hong-Bo, Wu Zhi-Feng, Wang Yi-Hong, Hu Bo, Jiang Zhi-Nong, Jin Mei, Wang Lin-Bo, Gao Ya-Bo
Department of Pathology, Sir Run Run Shaw Hospital, Zhejiang University College of Medicine, Hangzhou 310016, China.
Department of General Surgery, Xiangyang Central Hospital, Hubei University of Arts and Science, Xiangyang 441053, China.
Transl Cancer Res. 2019 Oct;8(6):2405-2415. doi: 10.21037/tcr.2019.09.54.
Regulatory T (Treg) cells are a major component of the microenvironment of hepatocellular carcinoma (HCC) contributing to immunosuppression. The present study aimed to evaluate the effects of Treg cells on the invasion potential of HCC.
Infiltrating Treg cells were isolated from fresh HCC tissues by immunomagnetic bead separation and detected by flow cytometry. Circulating tumor cells (CTCs) were detected using the CellSearch platform. The cell migration and invasion potentials were evaluated by Transwell assays. The cell viability was tested by the cell counting kit-8 (CCK8) approach, and the apoptosis rates were determined by flow cytometry. The concentrations of active transforming growth factor-β1 (TGFβ1) were measured by enzyme-linked immunosorbent assay.
Infiltrating Treg cells significantly correlated with the number of CTCs and vascular invasion (both P<0.05). Moreover, these cells could greatly promote HCC migration, invasion, and proliferation, and inhibit HCC apoptosis. Polymerase chain reaction and Western blot assays revealed that Treg cells significantly decreased the expression levels of epithelium-related molecules and increased the expression levels of mesenchyme-related molecules. Treg cells could activate Smad2/3 via secreting TGFβ1, and these effects could be impaired by knocking down the expression of TGFβ1 in Treg cells.
The involvement of infiltrating Treg cells in triggering the TGFβ1 signaling pathway and promoting the epithelial-mesenchymal transition (EMT) of cancer cells during tumor hematogenous dissemination is presumably responsible for increasing the invasiveness potential of HCC cells. Targeting Treg cells in microenvironments can be a promising therapeutic strategy to improve the prognosis for patients with HCC undergoing resection.
调节性T（Treg）细胞是肝细胞癌（HCC）微环境的主要组成部分，有助于免疫抑制。本研究旨在评估Treg细胞对HCC侵袭潜能的影响。
通过免疫磁珠分离从新鲜HCC组织中分离浸润性Treg细胞，并通过流式细胞术进行检测。使用CellSearch平台检测循环肿瘤细胞（CTC）。通过Transwell试验评估细胞迁移和侵袭潜能。采用细胞计数试剂盒-8（CCK8）法检测细胞活力，通过流式细胞术测定凋亡率。采用酶联免疫吸附测定法测量活性转化生长因子-β1（TGFβ1）的浓度。
浸润性Treg细胞与CTC数量和血管侵犯显著相关（均P<0.05）。此外，这些细胞可极大地促进HCC迁移、侵袭和增殖，并抑制HCC凋亡。聚合酶链反应和蛋白质印迹分析显示，Treg细胞显著降低上皮相关分子的表达水平，并增加间充质相关分子的表达水平。Treg细胞可通过分泌TGFβ1激活Smad2/3，而在Treg细胞中敲低TGFβ1的表达可削弱这些作用。
浸润性Treg细胞在肿瘤血行播散过程中参与触发TGFβ1信号通路并促进癌细胞上皮-间质转化（EMT），可能是导致HCC细胞侵袭潜能增加的原因。针对微环境中的Treg细胞可能是改善接受切除术的HCC患者预后的一种有前景的治疗策略。
