title: Molecular alterations in prostate carcinomas that associate with in vivo exposure to chemotherapy: identification of a cytoprotective mechanism involving growth differentiation factor 15.
abstract: OBJECTIVE
  To identify molecular alterations associating with in vivo exposure of prostate carcinoma to chemotherapy and assess functional roles modulating tumor response and resistance.
  
  
  METHODS
  Patients with high-risk localized prostate cancer (tumor-node-metastasis >or= T(2b) or prostate-specific antigen >or= 15 ng/mL or Gleason glade >or= 4+3) were enrolled into a phase II clinical trial of neoadjuvant chemotherapy with docetaxel and mitoxantrone followed by prostatectomy. Pretreatment prostate tissue was acquired by needle biopsy and posttreatment tissue was acquired by prostatectomy. Prostate epithelium was captured by microdissection, and transcript levels were quantitated by cDNA microarray hybridization. Gene expression changes associated with chemotherapy were determined by a random variance t test. Several were verified by quantitative reverse transcription PCR. In vitro analyses determining the influence of growth differentiation factor 15 (GDF15) on chemotherapy resistance were done.
  
  
  RESULTS
  Gene expression changes after chemotherapy were measured in 31 patients who completed four cycles of neoadjuvant chemotherapy. After excluding genes shown previously to be influenced by the radical prostatectomy procedure, we identified 51 genes with significant transcript level alterations following chemotherapy. This group included several cytokines, including GDF15, chemokine (C-X-C motif) ligand 10, and interleukin receptor 1beta. Overexpression of GDF15 or exposure of prostate cancer cell lines to exogenous recombinant GDF15 conferred resistance to docetaxel and mitoxantrone.
  
  
  CONCLUSIONS
  Consistent molecular alterations were identified in prostate cancer cells exposed to docetaxel and mitoxantrone chemotherapy. These alterations include transcripts encoding cytokines known to be regulated through the nuclear factor-kappaB pathway. Chemotherapy-induced cytokines and growth factors, such as GDF15, contribute to tumor cell therapy resistance and may serve as targets to improve responses.
authors.affiliation: Division of Human Biology and Clinical Research, Fred Hutchinson Cancer Research Center, Seattle, Washington 98105-1024, USA.
authors.forename: Chung-Ying
authors.initials: CY
authors.lastname: Huang
authors.forename: Tomasz M
authors.initials: TM
authors.lastname: Beer
authors.forename: Celestia S
authors.initials: CS
authors.lastname: Higano
authors.forename: Lawrence D
authors.initials: LD
authors.lastname: True
authors.forename: Robert
authors.initials: R
authors.lastname: Vessella
authors.forename: Paul H
authors.initials: PH
authors.lastname: Lange
authors.forename: Mark
authors.initials: M
authors.lastname: Garzotto
authors.forename: Peter S
authors.initials: PS
authors.lastname: Nelson
mesh_terms: D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D016207:Cytokines / Q000096:biosynthesis* / Q000737:chemistry*; D018076:DNA, Complementary / Q000378:metabolism; D005091:Exons; D015972:Gene Expression Regulation, Neoplastic; D055436:Growth Differentiation Factor 15; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D016207:Cytokines; D018076:DNA, Complementary; C526140:GDF15 protein, human; D055436:Growth Differentiation Factor 15; D012333:RNA, Messenger