title: Intravesical bacillus Calmette-Guérin efficiently reduces p70S6K1 but not 4E-BP1 phosphorylation in nonmuscle invasive bladder cancer.
abstract: OBJECTIVE
  We characterized the functional consequences of intravesical bacillus Calmette-Guérin on the molecular mechanism of the AKT/mTOR signaling pathway in nonmuscle invasive bladder cancer. To our knowledge this has not been reported previously.
  
  
  METHODS
  At age 7 weeks female Fischer 344 rats received 1.5 mg/kg MNU intravesically every other week for 6 weeks. They were randomized at 10 per group to MNU (0.2 ml vehicle), bacillus Calmette-Guérin (10(6) cfu Connaught strain), rapamycin (15 μg/ml) and bacillus Calmette-Guérin plus simultaneous rapamycin, each intravesically for 6 weeks. At week 15 the bladders were collected for histopathology, immunohistochemistry and immunoblot to determine p-AKT, Rictor, Raptor, p-4E-BP1, p-p70S6K1, p-AMPK-α, p-mTOR and p-p53.
  
  
  RESULTS
  Papillary carcinoma (pTa) and high grade intraepithelial neoplasia (pTis) predominated in the MNU group while normal urothelium, papillary and flat hyperplasia were more common in treated groups. Nonmuscle invasive bladder cancer treated with bacillus Calmette-Guérin showed suppression of p70S6K1 but not 4E-BP1 phosphorylation. This suggests that 4E-BP1 is regulated differently than p70S6K1, escaping the bacillus Calmette-Guérin action that occurs in a mTOR independent manner. The association of bacillus Calmette-Guérin with rapamycin but not rapamycin monotherapy affected p70S6K1 and 4E-BP1 phosphorylation with no features of in situ carcinoma (pTis).
  
  
  CONCLUSIONS
  The activation status of p70S6K1 and 4E-BP1 might be used to stratify patients who could benefit from targeting such molecular elements with multitarget/multidrug intravesical therapy. In the future 4E-BP1 might be a worthwhile new target for bacillus Calmette-Guérin refractory nonmuscle invasive bladder cancer.
authors.affiliation: Departments of Urology and Pathology, School of Medical Sciences, University of Campinas, UNICAMP, Campinas, São Paulo, Brazil.
authors.forename: Karen Linares
authors.initials: KL
authors.lastname: Ferrari
authors.affiliation: Departments of Urology and Pathology, School of Medical Sciences, University of Campinas, UNICAMP, Campinas, São Paulo, Brazil.
authors.forename: Juliana Alves
authors.initials: JA
authors.lastname: de Camargo
authors.affiliation: Departments of Urology and Pathology, School of Medical Sciences, University of Campinas, UNICAMP, Campinas, São Paulo, Brazil.
authors.forename: Guilherme Zweig
authors.initials: GZ
authors.lastname: Rocha
authors.affiliation: Departments of Urology and Pathology, School of Medical Sciences, University of Campinas, UNICAMP, Campinas, São Paulo, Brazil.
authors.forename: José B C
authors.initials: JB
authors.lastname: Carvalheira
authors.affiliation: Departments of Urology and Pathology, School of Medical Sciences, University of Campinas, UNICAMP, Campinas, São Paulo, Brazil.
authors.forename: Mário J A
authors.initials: MJ
authors.lastname: Saad
authors.affiliation: Departments of Urology and Pathology, School of Medical Sciences, University of Campinas, UNICAMP, Campinas, São Paulo, Brazil.
authors.forename: Athanase
authors.initials: A
authors.lastname: Billis
authors.affiliation: Departments of Urology and Pathology, School of Medical Sciences, University of Campinas, UNICAMP, Campinas, São Paulo, Brazil. Electronic address: reisleo.l@gmail.com.
authors.forename: Leonardo O
authors.initials: LO
authors.lastname: Reis
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D000276:Adjuvants, Immunologic / Q000008:administration & dosage* / Q000627:therapeutic use; D000283:Administration, Intravesical; D000818:Animals; D001500:BCG Vaccine / Q000008:administration & dosage* / Q000627:therapeutic use; D018797:Cell Cycle Proteins; D005260:Female; D009361:Neoplasm Invasiveness; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D051381:Rats; D011916:Rats, Inbred F344; D038762:Ribosomal Protein S6 Kinases, 70-kDa / Q000378:metabolism*; D001749:Urinary Bladder Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D000276:Adjuvants, Immunologic; D001500:BCG Vaccine; D018797:Cell Cycle Proteins; C087000:EIF4EBP1 protein, human; D010750:Phosphoproteins; D038762:Ribosomal Protein S6 Kinases, 70-kDa
keywords: BCG vaccine; Eif4ebp1 protein; carcinoma; mTOR protein; rat; urinary bladder