title: Abnormal Protein Glycosylation and Activated PI3K/Akt/mTOR Pathway: Role in Bladder Cancer Prognosis and Targeted Therapeutics.
abstract: Muscle invasive bladder cancer (MIBC, stage ≥T2) is generally associated with poor prognosis, constituting the second most common cause of death among genitourinary tumours. Due to high molecular heterogeneity significant variations in the natural history and disease outcome have been observed. This has also delayed the introduction of personalized therapeutics, making advanced stage bladder cancer almost an orphan disease in terms of treatment. Altered protein glycosylation translated by the expression of the sialyl-Tn antigen (STn) and its precursor Tn as well as the activation of the PI3K/Akt/mTOR pathway are cancer-associated events that may hold potential for patient stratification and guided therapy. Therefore, a retrospective design, 96 bladder tumours of different stages (Ta, T1-T4) was screened for STn and phosphorylated forms of Akt (pAkt), mTOR (pmTOR), S6 (pS6) and PTEN, related with the activation of the PI3K/Akt/mTOR pathway. In our series the expression of Tn was residual and was not linked to stage or outcome, while STn was statically higher in MIBC when compared to non-muscle invasive tumours (p = 0.001) and associated decreased cancer-specific survival (log rank p = 0.024). Conversely, PI3K/Akt/mTOR pathway intermediates showed an equal distribution between non-muscle invasive bladder cancer (NMIBC) and MIBC and did not associate with cancer-specif survival (CSS) in any of these groups. However, the overexpression of pAKT, pmTOR and/or pS6 allowed discriminating STn-positive advanced stage bladder tumours facing worst CSS (p = 0.027). Furthermore, multivariate Cox regression analysis revealed that overexpression of PI3K/Akt/mTOR pathway proteins in STn+ MIBC was independently associated with approximately 6-fold risk of death by cancer (p = 0.039). Mice bearing advanced stage chemically-induced bladder tumours mimicking the histological and molecular nature of human tumours were then administrated with mTOR-pathway inhibitor sirolimus (rapamycin). This decreased the number of invasive lesions and, concomitantly, the expression of STn and also pS6, the downstream effector of the PI3K/Akt/mTOR pathway. In conclusion, STn was found to be marker of poor prognosis in bladder cancer and, in combination with PI3K/Akt/mTOR pathway evaluation, holds potential to improve the stratification of stage disease. Animal experiments suggest that mTOR pathway inhibition could be a potential therapeutic approach for this specific subtype of MIBC.
authors.affiliation: Experimental Pathology and Therapeutics Group, Portuguese Institute of Oncology, Rua Dr. António Bernardino de Almeida, Porto, Portugal.|ICBAS, Abel Salazar Biomedical Sciences Institute, University of Porto, Porto, Portugal.|Health Sciences Faculty of University Fernando Pessoa, Porto, Portugal.
authors.forename: Céu
authors.initials: C
authors.lastname: Costa
authors.affiliation: Experimental Pathology and Therapeutics Group, Portuguese Institute of Oncology, Rua Dr. António Bernardino de Almeida, Porto, Portugal.|ICBAS, Abel Salazar Biomedical Sciences Institute, University of Porto, Porto, Portugal.|Health Sciences Faculty of University Fernando Pessoa, Porto, Portugal.
authors.forename: Sofia
authors.initials: S
authors.lastname: Pereira
authors.affiliation: Experimental Pathology and Therapeutics Group, Portuguese Institute of Oncology, Rua Dr. António Bernardino de Almeida, Porto, Portugal.|Nucleo de Investigação e Informação em Farmácia - Centro de Investigação em Saúde e Ambiente (CISA), School of Allied Health Sciences - Polytechnic Institute of Oporto, Porto, Portugal.|Institute of Pathology and Molecular Immunology of the University of Porto (IPATIMUP), Porto, Portugal.
authors.forename: Luís
authors.initials: L
authors.lastname: Lima
authors.affiliation: Experimental Pathology and Therapeutics Group, Portuguese Institute of Oncology, Rua Dr. António Bernardino de Almeida, Porto, Portugal.
authors.forename: Andreia
authors.initials: A
authors.lastname: Peixoto
authors.affiliation: Experimental Pathology and Therapeutics Group, Portuguese Institute of Oncology, Rua Dr. António Bernardino de Almeida, Porto, Portugal.
authors.forename: Elisabete
authors.initials: E
authors.lastname: Fernandes
authors.affiliation: Experimental Pathology and Therapeutics Group, Portuguese Institute of Oncology, Rua Dr. António Bernardino de Almeida, Porto, Portugal.
authors.forename: Diogo
authors.initials: D
authors.lastname: Neves
authors.affiliation: Experimental Pathology and Therapeutics Group, Portuguese Institute of Oncology, Rua Dr. António Bernardino de Almeida, Porto, Portugal.
authors.forename: Manuel
authors.initials: M
authors.lastname: Neves
authors.affiliation: Experimental Pathology and Therapeutics Group, Portuguese Institute of Oncology, Rua Dr. António Bernardino de Almeida, Porto, Portugal.
authors.forename: Cristiana
authors.initials: C
authors.lastname: Gaiteiro
authors.affiliation: Experimental Pathology and Therapeutics Group, Portuguese Institute of Oncology, Rua Dr. António Bernardino de Almeida, Porto, Portugal.|Department of Pathology, Portuguese Institute of Oncology, Porto, Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Tavares
authors.affiliation: Experimental Pathology and Therapeutics Group, Portuguese Institute of Oncology, Rua Dr. António Bernardino de Almeida, Porto, Portugal.|Faculty of Engineering, Laboratory for Process, Environment, Biotechnology and Energy Engineering (LEPABE), University of Porto, Porto, Portugal.
authors.forename: Rui M
authors.initials: RM
authors.lastname: Gil da Costa
authors.affiliation: Department of Urology, Portuguese Institute of Oncology, Porto, Portugal.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Cruz
authors.affiliation: Department of Urology, Hospital Pedro Hispano, Matosinhos, Portugal.
authors.forename: Teresina
authors.initials: T
authors.lastname: Amaro
authors.affiliation: Department of Veterinary Sciences, CITAB, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal.
authors.forename: Paula A
authors.initials: PA
authors.lastname: Oliveira
authors.affiliation: Experimental Pathology and Therapeutics Group, Portuguese Institute of Oncology, Rua Dr. António Bernardino de Almeida, Porto, Portugal.|Mass Spectrometry Center of the University of Aveiro, Campus de Santiago, Aveiro, Portugal.
authors.forename: José Alexandre
authors.initials: JA
authors.lastname: Ferreira
authors.affiliation: Experimental Pathology and Therapeutics Group, Portuguese Institute of Oncology, Rua Dr. António Bernardino de Almeida, Porto, Portugal.|Health Sciences Faculty of University Fernando Pessoa, Porto, Portugal.|Department of Surgical Oncology, Portuguese Institute of Oncology, Porto, Portugal.
authors.forename: Lúcio L
authors.initials: LL
authors.lastname: Santos
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D015295:Antigens, Tumor-Associated, Carbohydrate / Q000378:metabolism; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006031:Glycosylation; D006801:Humans; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D008875:Middle Aged; D009367:Neoplasm Staging; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D011379:Prognosis; D016016:Proportional Hazards Models; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D012189:Retrospective Studies; D015398:Signal Transduction; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism*; D016896:Treatment Outcome; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis / Q000378:metabolism* / Q000401:mortality / Q000628:therapy*
chemical_list: D015295:Antigens, Tumor-Associated, Carbohydrate; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; D058570:TOR Serine-Threonine Kinases; C055491:sialosyl-Tn antigen; C546842:MTOR protein, human; C494918:AKT1 protein, human