title: WNT1 gene expression alters in heterogeneous population of prostate cancer cells; decreased expression pattern observed in CD133+/CD44+ prostate cancer stem cell spheroids.
abstract: OBJECTIVE
  Established cancer cell lines contain cancer stem cells (CSCs) which can propagate to form three dimensional (3D) tumor spheroids in vitro. Aberrant activation of WNT signaling is strongly implicated in the progression of cancer and controls CSCs properties. In this study we hypothesized that when cells were maintained as spheroids, the structure of CSCs could show differentiation between CSCs and non- CSCs.
  
  
  METHODS
  CD133+/CD44+ cancer-initiating cells were isolated from DU-145 human prostate cancer cell line monolayer cultures, propagated as tumor spheroids and compared with the remaining heterogeneous cancer cells bulk population. The expression levels of WNT1, FZD1, ADAR, APC, AXIN, BTRC, FRAT1 and PPARD genes were measured by polymerase chain reaction (PCR) array assay and the protein expression levels of WNT1, FZD and AXIN by immunohistochemistry.
  
  
  RESULTS
  The expression levels of WNT pathway-related molecules were found to increase in both CSCs and non- CSCs when CSCs were maintained as spheroids. However, different expression profiles were observed when CSCs and non-CSCs were compared. In spheroids, the expression levels of FZD1, APC, ADAR, WNT1, PPARD genes in CSCs decreased when compared to non-CSCs. Interestingly, when CSCs from spheroids were compared with CSCs from monolayers the most significant decrease was observed in FZD1 and increase in APC genes.
  
  
  CONCLUSIONS
  It is possible to assume that intracellular signaling of WNT-related molecules in the nucleus and/or cytoplasm might play an important role but it is independent from increased ligand expression and this expression strongly differentiate CSCs and non-CSCs population. This unexpected expression could be important for CSCs behavior and targeting this pathway could have therapeutic implications in cancer.
authors.affiliation: Celal Bayar University Faculty of Medicine, Department of Medical Oncology, Manisa, Turkey.
authors.forename: Gamze
authors.initials: G
authors.lastname: Goksel
authors.forename: Ayhan
authors.initials: A
authors.lastname: Bilir
authors.forename: Ruchan
authors.initials: R
authors.lastname: Uslu
authors.forename: Hakan
authors.initials: H
authors.lastname: Akbulut
authors.forename: Ummu
authors.initials: U
authors.lastname: Guven
authors.forename: Gulperi
authors.initials: G
authors.lastname: Oktem
mesh_terms: D000071916:AC133 Antigen; D015703:Antigens, CD / Q000235:genetics*; D019070:Cell Lineage; D015972:Gene Expression Regulation, Neoplastic; D006023:Glycoproteins / Q000235:genetics*; D006801:Humans; D018960:Hyaluronan Receptors / Q000235:genetics*; D008297:Male; D014411:Neoplastic Stem Cells / Q000378:metabolism / Q000473:pathology; D010455:Peptides / Q000235:genetics*; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000473:pathology; D018874:Spheroids, Cellular / Q000378:metabolism / Q000473:pathology; D051155:Wnt1 Protein / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D000071916:AC133 Antigen; D015703:Antigens, CD; C497483:CD44 protein, human; D006023:Glycoproteins; D018960:Hyaluronan Receptors; C000606023:PROM1 protein, human; D010455:Peptides; C495247:WNT1 protein, human; D051155:Wnt1 Protein