title: Chinese herbal medicine Xiaoji decoction inhibited growth of lung cancer cells through AMPKα-mediated inhibition of Sp1 and DNA methyltransferase 1.
abstract: BACKGROUND
  Xiaoji decoction (XJD), which was considered as a Chinese herbal prescription, has been used for cancer treatment, especially lung cancer, for decades to improve quality of life and prolong the patient survival. However, the molecular mechanisms underlying the therapeutic potential have not been well elucidated.
  
  
  METHODS
  The cell viability was examined by MTT assays. The phosphorylation and expression of AMP-activated protein kinase alpha (AMPKα), DNA methyltransferase 1 (DNMT1) and transcription factor Sp1 proteins were assessed by Western Blot. Exogenous expression of Sp1 and DNMT1 were performed by transient transfection methods. The effects of XJD on the growth of xenograft tumors were evaluated by in vivo bioluminescence imaging.
  
  
  RESULTS
  We showed that XJD inhibited growth of human non small cell lung cancer (NSCLC) cells in vitro. We also found that XJD increased phosphorylation of AMPKα and inhibited protein expression of DNTM1, the latter was not observed in the presence of the inhibitor of AMPK (compound C). Overexpression of DNTM1 reversed the effect of XJD on cell growth. In addition, XJD decreased Sp1 protein expression, which was eliminated by compound C. Conversely, exogenous expressed Sp1 abrogated XJD-inhibited DNTM1 protein expression. Interestingly, exogenous expression of DNMT1 feedback antagonized the XJD-induced phosphorylation of AMPKα. In in vivo studies, we found that XJD inhibited tumor growth in xenograft nude mice model, which was accompanied by induction of phosphorylation of AMPKα and suppression of DNMT1 protein from xenograft tumors.
  
  
  CONCLUSIONS
  Our results show that XJD inhibits NSCLC cell growth via AMPKα-mediated inhibition of transcription of Sp1, followed by the reduction of DNMT1 expression both in vitro and in vivo. The negative feedback regulation loop of AMPKα further demonstrates the critical role of DNMT1 in mediating the overall effects of XJD in this process. This study unveils novel molecular mechanism by which XJD controls NSCLC cell growth.
authors: Laboratory of Tumor Biology, Guangdong Provincial Hospital of Chinese Medicine, The Second Clinical Medical Collage, University of Guangzhou Traditional Chinese Medicine, Guangzhou, Guangdong Province 510120, China.
authors: ShunYu
authors: S
authors: Zhao
authors: Laboratory of Tumor Biology, Guangdong Provincial Hospital of Chinese Medicine, The Second Clinical Medical Collage, University of Guangzhou Traditional Chinese Medicine, Guangzhou, Guangdong Province 510120, China.
authors: Jingjing
authors: J
authors: Wu
authors: Laboratory of Tumor Biology, Guangdong Provincial Hospital of Chinese Medicine, The Second Clinical Medical Collage, University of Guangzhou Traditional Chinese Medicine, Guangzhou, Guangdong Province 510120, China.
authors: Qing
authors: Q
authors: Tang
authors: Laboratory of Tumor Biology, Guangdong Provincial Hospital of Chinese Medicine, The Second Clinical Medical Collage, University of Guangzhou Traditional Chinese Medicine, Guangzhou, Guangdong Province 510120, China.
authors: Fang
authors: F
authors: Zheng
authors: Laboratory of Tumor Biology, Guangdong Provincial Hospital of Chinese Medicine, The Second Clinical Medical Collage, University of Guangzhou Traditional Chinese Medicine, Guangzhou, Guangdong Province 510120, China.
authors: LiJun
authors: L
authors: Yang
authors: Laboratory of Tumor Biology, Guangdong Provincial Hospital of Chinese Medicine, The Second Clinical Medical Collage, University of Guangzhou Traditional Chinese Medicine, Guangzhou, Guangdong Province 510120, China.
authors: YuQin
authors: Y
authors: Chen
authors: Department of Medical Oncology, Guangdong Provincial Hospital of Chinese Medicine, The Second Clinical Medical Collage, University of Guangzhou Traditional Chinese Medicine, Guangzhou, Guangdong Province 510120, China.
authors: Liuning
authors: L
authors: Li
authors: Laboratory of Tumor Biology, Guangdong Provincial Hospital of Chinese Medicine, The Second Clinical Medical Collage, University of Guangzhou Traditional Chinese Medicine, Guangzhou, Guangdong Province 510120, China. Electronic address: 18718844345@163.com.
authors: Swei Sunny
authors: SS
authors: Hann
mesh_terms: D000072283:A549 Cells; D055372:AMP-Activated Protein Kinases / Q000378:metabolism*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004247:DNA / Q000378:metabolism*; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D008780:Methyltransferases / Q000378:metabolism*; D051379:Mice; D008819:Mice, Nude; D010766:Phosphorylation / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects; D016329:Sp1 Transcription Factor / Q000378:metabolism*
chemical_list: D004365:Drugs, Chinese Herbal; D016329:Sp1 Transcription Factor; C000597954:xiaoji; D004247:DNA; D008780:Methyltransferases; D055372:AMP-Activated Protein Kinases
keywords: AMPKα; DNMT1; NSCLC; Sp1; Xiaoji decoction