title: Sp1 and c-Myc modulate drug resistance of leukemia stem cells by regulating survivin expression through the ERK-MSK MAPK signaling pathway.
abstract: BACKGROUND
  Acute myeloid leukemia (AML) is initiated and maintained by a subset of self-renewing leukemia stem cells (LSCs), which contribute to the progression, recurrence and therapeutic resistance of leukemia. However, the mechanisms underlying the maintenance of LSCs drug resistance have not been fully defined. In this study, we attempted to elucidate the mechanisms of LSCs drug resistance.
  
  
  METHODS
  We performed reverse phase protein arrays to analyze the expression of anti-apoptotic proteins in the LSC-enriched leukemia cell line KG-1a. Immuno-blotting, cell viability and clinical AML samples were evaluated to verify the micro-assay results. The characteristics and transcriptional regulation of survivin were analyzed with the relative luciferase reporter assay, mutant constructs, chromatin immuno-precipitation (ChIP), quantitative real-time reverse transcription polymerase chain reaction (RT-qPCR), and western blotting. The levels of Sp1, c-Myc, phospho-extracellular signal-regulated kinase (p-ERK), phospho-mitogen and stress-activated protein kinase (p-MSK) were investigated in paired CD34+ and CD34- AML patient samples.
  
  
  RESULTS
  Survivin was highly over-expressed in CD34 + CD38- KG-1a cells and paired CD34+ AML patients compared with their differentiated counterparts. Functionally, survivin contributes to the drug resistance of LSCs, and Sp1 and c-Myc concurrently regulate levels of survivin transcription. Clinically, Sp1 and c-Myc were significantly up-regulated and positively correlated with survivin in CD34+ AML patients. Moreover, Sp1 and c-Myc were further activated by the ERK/MSK mitogen-activated protein kinase (MAPK) signaling pathway, modulating survivin levels.
  
  
  CONCLUSIONS
  Our findings demonstrated that ERK/MSK/Sp1/c-Myc axis functioned as a critical regulator of survivin expression in LSCs, offering a potential new therapeutic strategy for LSCs therapy.
authors.affiliation: College of Life Science and Technology, Jinan University, 510632, Guangzhou, P.R, China. scholarzy@163.com.|Institute of Biomedicine, Jinan University, 510632, Guangzhou, P.R China. scholarzy@163.com.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: College of Medicine, Jinan University, 510632, Guangzhou, P.R China. chx00520@163.com.
authors.forename: Hai-xuan
authors.initials: HX
authors.lastname: Chen
authors.affiliation: Department of Pathological Physiology, Wan-nan Medical College, 241000, Wuhu, P.R China. zhoushuyan_xju2005@126.com.
authors.forename: Shu-yan
authors.initials: SY
authors.lastname: Zhou
authors.affiliation: College of Medicine, Shenzhen University, 518020, Shenzhen, P.R China. hackerwsx@163.com.
authors.forename: Shao-xiang
authors.initials: SX
authors.lastname: Wang
authors.affiliation: College of Medicine, Shenzhen University, 518020, Shenzhen, P.R China. y.k.zheng@163.com.
authors.forename: Kai
authors.initials: K
authors.lastname: Zheng
authors.affiliation: College of Life Science and Technology, Jinan University, 510632, Guangzhou, P.R, China. 496502190@qq.com.
authors.forename: Dan-dan
authors.initials: DD
authors.lastname: Xu
authors.affiliation: College of Life Science and Technology, Jinan University, 510632, Guangzhou, P.R, China. ziziniu@163.com.
authors.forename: Yu-ting
authors.initials: YT
authors.lastname: Liu
authors.affiliation: Institute of Biomedicine, Jinan University, 510632, Guangzhou, P.R China. wangxiaoyan_1016@163.com.
authors.forename: Xiao-yan
authors.initials: XY
authors.lastname: Wang
authors.affiliation: Institute of Biomedicine, Jinan University, 510632, Guangzhou, P.R China. wangxiao0719@163.com.
authors.forename: Xiao
authors.initials: X
authors.lastname: Wang
authors.affiliation: College of Life Science and Technology, Jinan University, 510632, Guangzhou, P.R, China. yanhaizhao@126.com.
authors.forename: Hai-Zhao
authors.initials: HZ
authors.lastname: Yan
authors.affiliation: College of Life Science and Technology, Jinan University, 510632, Guangzhou, P.R, China. 15692002254@163.com.
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Institute of Biomedicine, Jinan University, 510632, Guangzhou, P.R China. qiuying_liu@126.com.
authors.forename: Qiu-ying
authors.initials: QY
authors.lastname: Liu
authors.affiliation: College of Medicine, Jinan University, 510632, Guangzhou, P.R China. tchwanq@jnu.edu.cn.
authors.forename: Wan-qun
authors.initials: WQ
authors.lastname: Chen
authors.affiliation: College of Life Science and Technology, Jinan University, 510632, Guangzhou, P.R, China. twang-yf@163.com.|Institute of Biomedicine, Jinan University, 510632, Guangzhou, P.R China. twang-yf@163.com.
authors.forename: Yi-fei
authors.initials: YF
authors.lastname: Wang
mesh_terms: D000328:Adult; D018952:Antigens, CD34 / Q000235:genetics; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000235:genetics; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D005260:Female; D018922:HL-60 Cells; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins / Q000235:genetics*; D020014:K562 Cells; D015470:Leukemia, Myeloid, Acute / Q000235:genetics*; D020935:MAP Kinase Signaling System / Q000235:genetics*; D008297:Male; D020929:Mitogen-Activated Protein Kinase Kinases / Q000235:genetics*; D014411:Neoplastic Stem Cells / Q000378:metabolism; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics*; D015398:Signal Transduction / Q000235:genetics; D016329:Sp1 Transcription Factor / Q000235:genetics*; D000077022:Survivin; D014158:Transcription, Genetic / Q000235:genetics; D020298:U937 Cells; D015854:Up-Regulation / Q000235:genetics
chemical_list: D018952:Antigens, CD34; C107489:BIRC5 protein, human; D051034:Inhibitor of Apoptosis Proteins; C489427:MYC protein, human; D016271:Proto-Oncogene Proteins c-myc; D016329:Sp1 Transcription Factor; C108209:SP1 protein, human; D000077022:Survivin; D020929:Mitogen-Activated Protein Kinase Kinases