title: Monocarboxylate transporter 4 (MCT4) and CD147 overexpression is associated with poor prognosis in prostate cancer.
abstract: BACKGROUND
  Monocarboxylate transporters (MCTs) are transmembrane proteins involved in the transport of monocarboxylates across the plasma membrane, which appear to play an important role in solid tumours, however the role of MCTs in prostate cancer is largely unknown. The aim of the present work was to evaluate the clinico-pathological value of monocarboxylate transporters (MCTs) expression, namely MCT1, MCT2 and MCT4, together with CD147 and gp70 as MCT1/4 and MCT2 chaperones, respectively, in prostate carcinoma.
  
  
  METHODS
  Prostate tissues were obtained from 171 patients, who performed radical prostatectomy and 14 patients who performed cystoprostatectomy. Samples and clinico-pathological data were retrieved and organized into tissue microarray (TMAs) blocks. Protein expression was evaluated by immunohistochemistry in neoplastic (n = 171), adjacent non-neoplastic tissues (n = 135), PIN lesions (n = 40) and normal prostatic tissue (n = 14). Protein expression was correlated with patients' clinicopathologic characteristics.
  
  
  RESULTS
  In the present study, a significant increase of MCT2 and MCT4 expression in the cytoplasm of tumour cells and a significant decrease in both MCT1 and CD147 expression in prostate tumour cells was observed when compared to normal tissue. All MCT isoforms and CD147 were expressed in PIN lesions. Importantly, for MCT2 and MCT4 the expression levels in PIN lesions were between normal and tumour tissue, which might indicate a role for these MCTs in the malignant transformation. Associations were found between MCT1, MCT4 and CD147 expressions and poor prognosis markers; importantly MCT4 and CD147 overexpression correlated with higher PSA levels, Gleason score and pT stage, as well as with perineural invasion and biochemical recurrence.
  
  
  CONCLUSIONS
  Our data provides novel evidence for the involvement of MCTs in prostate cancer. According to our results, we consider that MCT2 should be further explored as tumour marker and both MCT4 and CD147 as markers of poor prognosis in prostate cancer.
authors.affiliation: Life and Health Sciences Research Institute, School of Health Sciences, University of Minho, Braga, Portugal.
authors.forename: Nelma
authors.initials: N
authors.lastname: Pértega-Gomes
authors.forename: José R
authors.initials: JR
authors.lastname: Vizcaíno
authors.forename: Vera
authors.initials: V
authors.lastname: Miranda-Gonçalves
authors.forename: Céline
authors.initials: C
authors.lastname: Pinheiro
authors.forename: Joana
authors.initials: J
authors.lastname: Silva
authors.forename: Helena
authors.initials: H
authors.lastname: Pereira
authors.forename: Pedro
authors.initials: P
authors.lastname: Monteiro
authors.forename: Rui M
authors.initials: RM
authors.lastname: Henrique
authors.forename: Rui M
authors.initials: RM
authors.lastname: Reis
authors.forename: Carlos
authors.initials: C
authors.lastname: Lopes
authors.forename: Fátima
authors.initials: F
authors.lastname: Baltazar
mesh_terms: D000368:Aged; D051926:Basigin / Q000096:biosynthesis*; D014408:Biomarkers, Tumor / Q000096:biosynthesis*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008562:Membrane Glycoproteins / Q000096:biosynthesis; D008875:Middle Aged; D018832:Molecular Chaperones; D027501:Monocarboxylic Acid Transporters / Q000096:biosynthesis*; D009124:Muscle Proteins / Q000096:biosynthesis*; D011379:Prognosis; D011467:Prostate / Q000378:metabolism / Q000473:pathology; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D027981:Symporters / Q000096:biosynthesis; D046888:Tissue Array Analysis; D000099233:Monocarboxylate Transport Protein 1
chemical_list: D051926:Basigin; D014408:Biomarkers, Tumor; D008562:Membrane Glycoproteins; D018832:Molecular Chaperones; D027501:Monocarboxylic Acid Transporters; D009124:Muscle Proteins; D027981:Symporters; D000099233:Monocarboxylate Transport Protein 1; C497886:BSG protein, human; C069503:EMB protein, human; C406962:SLC16A4 protein, human; C490427:SLC16A7 protein, human