title: Temsirolimus improves cytotoxic efficacy of cisplatin and gemcitabine against urinary bladder cancer cell lines.
abstract: OBJECTIVE
  To analyze the cytotoxic action of temsirolimus using 3 established human bladder cancer cell lines and to assess whether temsirolimus potentiates the anticancer activity of gemcitabine and cisplatin.
  
  
  METHODS
  Temsirolimus (500, 1,000, 2,000, and 4,000 nM), in isolation, and combined with gemcitabine (100 nM) and cisplatin (2.5 µg/ml), was given to 5637, T24, and HT1376 bladder cancer cell lines. Cell proliferation, autophagy, early apoptosis, and cell cycle distribution were analyzed after a 72-hour period. The expression of mammalian target of rapamycin baseline, Akt, and their phosphorylated forms, before and after treatment with temsirolimus, was evaluated by immunoblotting.
  
  
  RESULTS
  Temsirolimus slightly decreased the bladder cancer cell proliferation in all 3 cell lines. No significant differences in the expression of mammalian target of rapamycin, Akt, and their phosphorylated forms because of temsirolimus exposure were found in the 3 cell lines. As part of a combined regime along with gemcitabine, and especially with cisplatin, there was a more pronounced antiproliferative effect. This pattern of response was similar to the other parameters analyzed (increased autophagy and apoptosis). Also, in the combined regime, an enhanced cell cycle arrest in the G0/G1 phase was observed. The non-muscle invasive 5637 bladder cancer cell line was most sensitive to both combinations.
  
  
  CONCLUSIONS
  Temsirolimus makes a moderate contribution in terms of cell proliferation, apoptosis, and autophagy. However, it does potentiate the activity of gemcitabine and particularly cisplatin. Therefore, cisplatin- or gemcitabine-based chemotherapy regimen used in combination with temsirolimus to treat bladder cancer represents a novel and valuable treatment option, which should be tested for future studies in urinary bladder xenograft models.
authors.affiliation: Genetic Service, Cytogenetic Laboratory, Hospital Center of Trás-os-Montes and Alto Douro, Vila Real, Portugal.
authors.forename: Rosário
authors.initials: R
authors.lastname: Pinto-Leite
authors.affiliation: Department of Veterinary Sciences, School of Agrarian and Veterinarian Sciences, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal.
authors.forename: Regina
authors.initials: R
authors.lastname: Arantes-Rodrigues
authors.affiliation: QOPNA, Mass Spectrometry Center, Department of Chemistry, University of Aveiro, Aveiro, Portugal.
authors.forename: Rita
authors.initials: R
authors.lastname: Ferreira
authors.affiliation: Experimental Pathology and Therapeutics Group, Portuguese Institute of Oncology, Porto, Portugal; Health School, University Fernando Pessoa, Porto, Portugal.
authors.forename: Carlos
authors.initials: C
authors.lastname: Palmeira
authors.affiliation: Department of Veterinary Sciences, School of Agrarian and Veterinarian Sciences, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal.
authors.forename: Aura
authors.initials: A
authors.lastname: Colaço
authors.affiliation: Department of Urology, Portuguese Institute of Oncology, Porto, Portugal.
authors.forename: Vítor
authors.initials: V
authors.lastname: Moreira da Silva
authors.affiliation: CECA, ICETA, University of Porto, Porto, Portugal. Electronic address: pamo@utad.pt.
authors.forename: Paula
authors.initials: P
authors.lastname: Oliveira
authors.affiliation: Experimental Pathology and Therapeutics Group, Portuguese Institute of Oncology, Porto, Portugal; Health School, University Fernando Pessoa, Porto, Portugal.
authors.forename: Lúcio
authors.initials: L
authors.lastname: Lara Santos
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D001343:Autophagy / Q000187:drug effects; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002945:Cisplatin / Q000494:pharmacology*; D003841:Deoxycytidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D006801:Humans; D015151:Immunoblotting; D008856:Microscopy, Fluorescence; D010766:Phosphorylation / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D020123:Sirolimus / Q000031:analogs & derivatives* / Q000494:pharmacology; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism; D001749:Urinary Bladder Neoplasms / Q000378:metabolism / Q000473:pathology; D000093542:Gemcitabine
chemical_list: D000970:Antineoplastic Agents; D003841:Deoxycytidine; C401859:temsirolimus; D051057:Proto-Oncogene Proteins c-akt; D058570:TOR Serine-Threonine Kinases; D002945:Cisplatin; D020123:Sirolimus; D000093542:Gemcitabine
keywords: Bladder cancer cell lines; Cisplatin; Combination chemotherapy; Gemcitabine; Temsirolimus