title: Activation of cyclic AMP/PKA pathway inhibits bladder cancer cell invasion by targeting MAP4-dependent microtubule dynamics.
abstract: OBJECTIVE
  With the notorious reputation of the vicious invasion, the bladder cancer is the most common malignant tumor of the urinary system. Inhibiting invasion through microtubule dynamics interruption has emerged as an important treatment of bladder cancer. Here we investigated the role of the cyclic adenosine monophosphate/protein kinase A (cAMP/PKA) pathway in human bladder cancer cells invasion.
  
  
  METHODS
  With or without the treatment of various cAMP elevators, we assessed invasive and migrated capabilities of T24 and UM-UC-3, two high-grade invasive bladder cancer cell lines, using matrigel transwell inserts assay and scratch wound healing assay. The microtubule (MT) dynamics were examined by immunofluorescence and immunoblotting. Microtubule-Associated Protein 4 (MAP4) was silenced to investigate its role in tumor invasion. We also analyzed gene expression of MAP4 in 34 patients with bladder cancer using immunohistochemical staining assay. The interaction between PKA and MAP4 was examined by co-immunoprecipitation.
  
  
  RESULTS
  We used cAMP elevators and small interfering RNA of MAP4 here, found that both of them can potently inhibit the invasion and the migration of bladder cancer cells by disrupting microtubule (MT) cytoskeleton. Consistently, the bladder cancer grade is positively correlated with the protein level of MAP4. Furthermore, we found that cAMP/PKA signaling can disrupt MT cytoskeleton by the phosphorylation of MAP4.
  
  
  CONCLUSIONS
  Our results indicated that the cAMP/PKA signaling pathway might inhibit bladder cancer cell invasion by targeting MAP4-dependent microtubule dynamics, which could be exploited for the therapy of invasive bladder cancer.
authors.affiliation: Department of Pharmacology, Zhong-shan Medical College, Sun Yat-Sen University, Guangzhou, P.R. China; Guangdong Provincial Cardiovascular Institute, Guangdong General Hospital, Guangdong Provincial Academy of Medical Sciences, Guangzhou, P.R. China.
authors.forename: Yanqiu
authors.initials: Y
authors.lastname: Ou
authors.affiliation: Department of Phathology, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, P.R. China; Department of Pharmacology, Zhong-shan Medical College, Sun Yat-Sen University, Guangzhou, P.R. China.
authors.forename: Xiaoke
authors.initials: X
authors.lastname: Zheng
authors.affiliation: Department of Neurobiology, College of Basic Medical Science, The Third Military Medical University, Chongqing, P.R. China.
authors.forename: Yixing
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Department of Pharmacology, Zhong-shan Medical College, Sun Yat-Sen University, Guangzhou, P.R. China.
authors.forename: Minfeng
authors.initials: M
authors.lastname: Shu
authors.affiliation: Department of Pharmacology, Zhong-shan Medical College, Sun Yat-Sen University, Guangzhou, P.R. China.
authors.forename: Tiandong
authors.initials: T
authors.lastname: Leng
authors.affiliation: Department of Pharmacology, Zhong-shan Medical College, Sun Yat-Sen University, Guangzhou, P.R. China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Biochemistry, Zhong-shan Medical College, Sun Yat-Sen University, Guangzhou, P.R. China.
authors.forename: Wei
authors.initials: W
authors.lastname: Yin
authors.affiliation: Department of Pharmacology, Zhong-shan Medical College, Sun Yat-Sen University, Guangzhou, P.R. China.
authors.forename: Wenbo
authors.initials: W
authors.lastname: Zhu
authors.affiliation: Department of Pharmacology, Zhong-shan Medical College, Sun Yat-Sen University, Guangzhou, P.R. China.
authors.forename: Yijun
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Department of Pharmacology, Zhong-shan Medical College, Sun Yat-Sen University, Guangzhou, P.R. China.
authors.forename: Yuxi
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Department of Pharmacology, Zhong-shan Medical College, Sun Yat-Sen University, Guangzhou, P.R. China.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Tang
authors.affiliation: Department of Pharmacology, Zhong-shan Medical College, Sun Yat-Sen University, Guangzhou, P.R. China.
authors.forename: Pengxin
authors.initials: P
authors.lastname: Qiu
authors.affiliation: Department of Pharmacology, Zhong-shan Medical College, Sun Yat-Sen University, Guangzhou, P.R. China.
authors.forename: Guangmei
authors.initials: G
authors.lastname: Yan
authors.affiliation: Department of Microbiology, Zhong-shan School of Medcine, Sun Yat-Sen University, Guangzhou, P.R. China; Department of Pharmacology, Zhong-shan Medical College, Sun Yat-Sen University, Guangzhou, P.R. China. Electronic address: hujun@mail.sysu.edu.cn.
authors.forename: Jun
authors.initials: J
authors.lastname: Hu
authors.affiliation: Department of Neurobiology, College of Basic Medical Science, The Third Military Medical University, Chongqing, P.R. China. Electronic address: Ruanhzruan61@yahoo.com.
authors.forename: Huaizhen
authors.initials: H
authors.lastname: Ruan
authors.affiliation: Department of Pharmaceutics, School of Pharmaceutical Science, Sun Yat-Sen University, Guangzhou, P.R. China. Electronic address: lsshhy@mail.sysu.edu.cn.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Hu
mesh_terms: D003994:Bucladesine / Q000494:pharmacology; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D002772:Cholera Toxin / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism*; D054751:Cyclic AMP-Dependent Protein Kinase Catalytic Subunits / Q000235:genetics / Q000378:metabolism*; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D018613:Microscopy, Confocal; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D008870:Microtubules / Q000187:drug effects / Q000378:metabolism; D009361:Neoplasm Invasiveness; D010766:Phosphorylation / Q000187:drug effects; D011485:Protein Binding; D034622:RNA Interference; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D014404:Tubulin / Q000378:metabolism; D001749:Urinary Bladder Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology
chemical_list: D008869:Microtubule-Associated Proteins; D014404:Tubulin; D003994:Bucladesine; D002772:Cholera Toxin; D000242:Cyclic AMP; D054751:Cyclic AMP-Dependent Protein Kinase Catalytic Subunits
keywords: Cyclic AMP/PKA pathway; Human bladder cancer; Invasion; MAP4; Microtubules