Liu Yutao, Cui Pingping, Chen Jiming, Li Wanshan
Department of Oral and Maxillofacial Surgery, Children's Hospital, Chongqing Medical University, Chongqing 400014, P.R. China.
Department of Stomatology, Central Hospital, Shengli Oil Field, Dongying, Shandong 257000, P.R. China.
Mol Med Rep. 2015 May;11(5):3642-6. doi: 10.3892/mmr.2014.3133. Epub 2014 Dec 24.
A subset of cancer stem cells termed 'side population' (SP) cells has been identified in several types of solid tumor and is known to be responsible for the failure of chemotherapy and for cancer relapse. In the present study, the oral squamous cell carcinoma (OSCC) cell line SCC‑55 was used for analysis of the SP cells based on Hoechst 33342 exclusion, via the ATP‑binding cassette (ABC) transporter, with and without verapamil using fluorescence activated cell sorting. The results demonstrated that the presence of SP cells in the SCC‑55 cell line was 2.8%, which was reduced to 0.6% in the presence of verapamil, an inhibitor of the ABC transporter. In addition, following exposure to the chemotherapeutic drug 5‑fluorouracil, a high survival rate was observed in the SP cells due to overexpression of the ABCG2 and B‑cell lymphoma 2 proteins. In addition, overexpression of stem cell surface markers, including CD44 and CD147 was observed in the SP cells. Therefore, these findings suggested that OSCC contains SP cells, which share certain characteristics with stem cells. The coexpression of ABC transporters and stem cell surface markers in SP cells may be associated with resistance to chemotherapeutic agents and also supports a role for these cells in tumor recurrence, metastasis and invasion.
在几种实体瘤中已鉴定出一类称为“侧群”（SP）细胞的癌症干细胞亚群，已知其与化疗失败和癌症复发有关。在本研究中，口腔鳞状细胞癌（OSCC）细胞系SCC-55用于基于Hoechst 33342排除法，通过ATP结合盒（ABC）转运蛋白，在有和没有维拉帕米的情况下，使用荧光激活细胞分选来分析SP细胞。结果表明，SCC-55细胞系中SP细胞的存在率为2.8%，在ABC转运蛋白抑制剂维拉帕米存在的情况下，该比例降至0.6%。此外，在暴露于化疗药物5-氟尿嘧啶后，由于ABCG2和B细胞淋巴瘤2蛋白的过表达，在SP细胞中观察到高存活率。另外，在SP细胞中观察到包括CD44和CD147在内的干细胞表面标志物的过表达。因此，这些发现表明OSCC含有SP细胞，其与干细胞具有某些共同特征。SP细胞中ABC转运蛋白和干细胞表面标志物的共表达可能与对化疗药物产生抗性有关，也支持这些细胞在肿瘤复发、转移和侵袭中的作用。
