Wang Hang, Yang Miqing, Lin Ling, Ren Hongzhen, Lin Chaotong, Lin Suling, Shen Guoying, Ji Binfeng, Meng Chun
Institute of Pharmaceutical Biotechnology and Engineering, College of Biological Science and Biotechnology, Fuzhou University, Fuzhou, Fujian, 350108, China.
, Qi Shan Campus, 2 Xue Yuan Road, University Town, Fuzhou, Fujian, 350108, People's Republic of China.
Cell Oncol (Dordr). 2016 Feb;39(1):35-45. doi: 10.1007/s13402-015-0249-1. Epub 2015 Dec 9.
The presence of cancer stem cells (CSCs) is currently regarded as one of the main culprits of tumor formation and therapy failure. It is known that chronic inflammation is associated with CSCs, but it is not clear yet how inflammation affects the development of CSCs. In the present study we aimed to examine the relationship between cancer cell stimulation mediated by immune cells and the acquisition of a CSC-like phenotype.
Cancer cells derived from single hepatocarcinoma HepG2 cells were treated with mouse splenic B cells (MSBCs) and mouse peritoneal macrophage cells (MPMCs), respectively. The stem cell-like characteristics of the resulting HepG2 cells (MSBC-HepG2 and MPMC-HepG2) were evaluated using different assays, including biomarker assays, in vitro tumoroid and colony forming assays, in vivo tumor forming assays and signal transduction pathway activation assays.
Various stemness characteristics of HepG2 cells, including self-renewal, proliferation, chemoresistance and tumorigenicity were evaluated. The expression levels of stemness-related genes and its encoded proteins in the MSBC-HepG2 and MPMC-HepG2 cells were assessed using RT-PCR and FACS analyses. We found that MSBC-HepG2 and MPMC-HepG2 cells possess hepatic CSC properties, including persistent self-renewal, extensive proliferation, drug resistance, high tumorigenic capacity and over-expression of CSC-related genes and proteins (i.e., EpCAM, ALDH, CD133 and CD44), compared to the parental cells. We also found that 1x10(3) MSBC-HepG2 and MPMC-HepG2 cells were able to form tumors in NOD/SCID mice and that the Notch and SHH signaling pathways were highly activated in MSBC-HepG2 cells.
We conclude that the immune system may have a double-edge effect on cancer development. On one hand, immune cells such as B lymphocytes and macrophages may recognize, attack and eliminate cancer cells, whereas on the other hand, they may promote a subset of cancer cells to acquire stem cell-like characteristics.
癌症干细胞（CSCs）的存在目前被认为是肿瘤形成和治疗失败的主要原因之一。已知慢性炎症与癌症干细胞有关，但炎症如何影响癌症干细胞的发展尚不清楚。在本研究中，我们旨在研究免疫细胞介导的癌细胞刺激与获得癌症干细胞样表型之间的关系。
分别用小鼠脾脏B细胞（MSBCs）和小鼠腹腔巨噬细胞（MPMCs）处理源自单个肝癌HepG2细胞的癌细胞。使用不同的检测方法评估所得HepG2细胞（MSBC-HepG2和MPMC-HepG2）的干细胞样特征，包括生物标志物检测、体外肿瘤球和集落形成检测、体内肿瘤形成检测以及信号转导通路激活检测。
评估了HepG2细胞的各种干性特征，包括自我更新、增殖、化学抗性和致瘤性。使用RT-PCR和FACS分析评估了MSBC-HepG2和MPMC-HepG2细胞中干性相关基因及其编码蛋白的表达水平。我们发现，与亲代细胞相比，MSBC-HepG2和MPMC-HepG2细胞具有肝癌症干细胞特性，包括持续自我更新、广泛增殖、耐药性、高致瘤能力以及癌症干细胞相关基因和蛋白（即EpCAM、ALDH、CD133和CD44）的过表达。我们还发现，1×10³个MSBC-HepG2和MPMC-HepG2细胞能够在NOD/SCID小鼠中形成肿瘤，并且Notch和SHH信号通路在MSBC-HepG2细胞中高度激活。
我们得出结论，免疫系统可能对癌症发展具有双刃剑效应。一方面，B淋巴细胞和巨噬细胞等免疫细胞可能识别、攻击和消除癌细胞，而另一方面，它们可能促进一部分癌细胞获得干细胞样特征。
