title: Effect of shRNA-Mediated Gene Silencing of Bmi-1 Expression on Chemosensitivity of CD44+ Nasopharyngeal Carcinoma Cancer Stem-Like Cells.
abstract: In this study, we investigate the effect of short hairpin RNA-mediated gene silencing of Bmi-1 expression on chemosensitivity of CD44(+) nasopharyngeal carcinoma cancer stem-like cells. The sequence-specific short hairpin RNA lentivirus targeting at human Bmi-1 was synthesized and used to infect CD44(+) nasopharyngeal cells that were sorted by flow cytometry. We also employed flow cytometry to detect transfection efficiency. Real-time polymerase chain reaction was used to detect Bmi-1 and its downstream repressor genes p16(INK4a) and p14(ARF) messenger RNA, while each protein expression level of Bmi-1, p16(INK4a), p14(ARF), and p53 was confirmed by Western blotting protocol. Tumor spheroid assay was used to evaluate the self-renewal capacity. 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay and colony formation assay were applied to detect proliferation capacity and colony-forming capacity under different concentrations of chemotherapeutic drugs 5-fluorouracil or cisplatin. Transwell cell migration and invasion assay were employed to observe migration and invasion capacity after cells were exposed to cisplatin for 24 hours. The constructed short hairpin RNA lentivirus targeting Bmi-1 gene successfully infected into the CD44(+) nasopharyngeal carcinoma cells and effectively inhibited the Bmi-1 messenger RNA and protein expression level, while the expression level of Bim-1 target genes, p16(INK4a), p14(ARF), and p53 was significantly increased (P < .05). Notably, the proliferation, colony formation, migration, and invasion capabilities of the sequence-specific short hairpin RNA lentivirus-infected CD44(+) nasopharyngeal carcinoma cells reduced significantly under chemotherapeutic treatments (P < .05). Our results indicated that Bmi-1 may play an important role in the chemosensitivity of CD44(+) nasopharyngeal carcinoma cancer stem-like cells. Bmi-1 may be a potential new target for the treatment of nasopharyngeal carcinoma displaying chemotherapy resistance.
authors: The First College of Clinical Medical Science, China Three Gorges University & Department of Oncology, Yichang Central People's Hospital, Yichang, China Oncology Institute, China Three Gorges University, Yichang, China xuxinhua@medmail.com.cn.
authors: Xin-Hua
authors: XH
authors: Xu
authors: The First College of Clinical Medical Science, China Three Gorges University & Department of Oncology, Yichang Central People's Hospital, Yichang, China Oncology Institute, China Three Gorges University, Yichang, China.
authors: Yang
authors: Y
authors: Liu
authors: The First College of Clinical Medical Science, China Three Gorges University & Department of Oncology, Yichang Central People's Hospital, Yichang, China Oncology Institute, China Three Gorges University, Yichang, China.
authors: Dao-Jun
authors: DJ
authors: Li
authors: The First College of Clinical Medical Science, China Three Gorges University & Department of Oncology, Yichang Central People's Hospital, Yichang, China Oncology Institute, China Three Gorges University, Yichang, China.
authors: Juan
authors: J
authors: Hu
authors: The First College of Clinical Medical Science, China Three Gorges University & Department of Oncology, Yichang Central People's Hospital, Yichang, China.
authors: Jin
authors: J
authors: Su
authors: The First College of Clinical Medical Science, China Three Gorges University & Department of Oncology, Yichang Central People's Hospital, Yichang, China.
authors: Qiao
authors: Q
authors: Huang
authors: The First College of Clinical Medical Science, China Three Gorges University & Department of Oncology, Yichang Central People's Hospital, Yichang, China.
authors: Ming-Qian
authors: MQ
authors: Lu
authors: The First College of Clinical Medical Science, China Three Gorges University & Department of Oncology, Yichang Central People's Hospital, Yichang, China Oncology Institute, China Three Gorges University, Yichang, China.
authors: Fang
authors: F
authors: Yi
authors: The First College of Clinical Medical Science, China Three Gorges University & Department of Oncology, Yichang Central People's Hospital, Yichang, China Oncology Institute, China Three Gorges University, Yichang, China.
authors: Dan
authors: D
authors: Bao
authors: The First College of Clinical Medical Science, China Three Gorges University & Department of Oncology, Yichang Central People's Hospital, Yichang, China Oncology Institute, China Three Gorges University, Yichang, China.
authors: Yan-Zhi
authors: YZ
authors: Fu
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D015415:Biomarkers; D002277:Carcinoma / Q000235:genetics* / Q000378:metabolism; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics; D000066673:Cell Self Renewal / Q000235:genetics; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D015972:Gene Expression Regulation, Neoplastic; D020868:Gene Silencing; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D018960:Hyaluronan Receptors / Q000235:genetics* / Q000378:metabolism; D016086:Lentivirus / Q000235:genetics; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000235:genetics* / Q000378:metabolism; D014411:Neoplastic Stem Cells / Q000187:drug effects* / Q000378:metabolism*; D063150:Polycomb Repressive Complex 1 / Q000235:genetics*; D012333:RNA, Messenger; D034741:RNA, Small Interfering / Q000235:genetics*
chemical_list: D000970:Antineoplastic Agents; C069077:BMI1 protein, human; D015415:Biomarkers; D018960:Hyaluronan Receptors; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D063150:Polycomb Repressive Complex 1
keywords: Bmi-1 gene; CD44; cancer stem-like cells; chemosensitivity; nasopharyngeal carcinoma