Guan Guo-Fang, Zhang De-Jun, Zheng Ying, Wen Lian-Ji, Yu Duo-Jiao, Lu Yan-Qing, Zhao Yan
Department of Otolaryngology, Head and Neck Surgery, The Second Hospital of Jilin University, Changchun, Jilin 130041, P.R. China.
Department of Otolaryngology, Head and Neck Surgery, Tumor Hospital of Jilin Province, Changchun, Jilin 130012, P.R. China.
Mol Med Rep. 2015 Sep;12(3):4352-4357. doi: 10.3892/mmr.2015.3935. Epub 2015 Jun 16.
The presence of cancer stem cells (CSCs) has major implications in the choice of cancer treatment strategy and is responsible for tumor relapse. CSCs have been isolated and characterized in several types of cancer; however, studies concerning the CSCs from nasopharyngeal carcinoma (NPC) are limited. Thus, the present study was designed to isolate and characterize the cancer stem-like side population (SP) cells from NPC samples. The fluorescence-activated cell sorting (FACS)-based Hoechst 33342 dye exclusion technique identified that 3.9% of cells from NPC samples were cancer stem-like SP cells. Upon treatment with verapamil (ABC transporter inhibitor), the percentage of SP cells was significantly reduced to 0.7%, which confirms that the ABC transporter protein exhibits a significant role in drug exclusion. Fluorescence microscopy analysis revealed that the FACS purified SP cells showed increased expression of ABCG2 (ATP transporter protein), Oct-4 and CD44 (stem cell surface protein). Furthermore, these SP cells exhibited increased mRNA expression of ABCG2 and anti-apoptotic factor Bmi-1, which contribute to multi-drug resistance and increased cell survival rate. Notably, the Wnt/β-catenin signaling pathways are altered in SP cells. In addition, using reverse transcription‑quantitative polymerase chain reaction analysis it was observed that the cells exhibited increased expression of DKK1 and AXIN2. In conclusion, data from the present study clearly demonstrated that the presence of cancer stem-like SP cells from NPC may be responsible for chemotherapeutic drug resistance, tumor recurrence and invasion.
癌症干细胞（CSCs）的存在对癌症治疗策略的选择具有重要意义，并且是肿瘤复发的原因。CSCs已在多种癌症类型中被分离和鉴定；然而，关于鼻咽癌（NPC）中CSCs的研究有限。因此，本研究旨在从NPC样本中分离和鉴定癌症干细胞样侧群（SP）细胞。基于荧光激活细胞分选（FACS）的Hoechst 33342染料排除技术鉴定出，NPC样本中3.9%的细胞为癌症干细胞样SP细胞。用维拉帕米（ABC转运蛋白抑制剂）处理后，SP细胞的百分比显著降低至0.7%，这证实了ABC转运蛋白在药物排除中发挥了重要作用。荧光显微镜分析显示，FACS纯化的SP细胞显示ABCG2（ATP转运蛋白）、Oct-4和CD44（干细胞表面蛋白）的表达增加。此外，这些SP细胞表现出ABCG2和抗凋亡因子Bmi-1的mRNA表达增加，这导致多药耐药性和细胞存活率增加。值得注意的是，Wnt/β-连环蛋白信号通路在SP细胞中发生改变。此外，通过逆转录-定量聚合酶链反应分析观察到，这些细胞表现出DKK1和AXIN2的表达增加。总之，本研究的数据清楚地表明，NPC中癌症干细胞样SP细胞的存在可能是化疗耐药、肿瘤复发和侵袭的原因。
