title: Role of microRNAs in drug-resistant ovarian cancer cells.
abstract: OBJECTIVE
  Chemotherapy is the preferred therapeutic approach for the therapy of advanced ovarian cancer, but a successful long-term treatment is prevented by the development of drug resistance. Recent works have underlined the involvement of non-coding RNAs, microRNAs (miRNAs) in cancer development, with several conjectures regarding their possible involvement in the evolution of drug resistance. This work was aimed to identify selected microRNAs involved in the development of chemoresistance in ovarian cancer.
  
  
  METHODS
  High-throughput analysis of the miRNA profile in a panel of paclitaxel- (A2780TAX, A2780TC1 and A2780TC3) and cisplatin-resistant (A2780CIS) cells was assessed using a microarray platform and subsequent validation with qPCR and Northern blots. Downstream target validation was performed for miR-130a and the target M-CSF.]
  
  
  RESULTS
  Six miRNAs (let-7e, miR-30c, miR-125b, miR-130a and miR-335) were always diversely expressed in all the resistant cell lines. Let-7e was upregulated in A2780TAX cells, while it was downregulated in the other resistant cell lines. The opposite phenomenon was obtained for miR-125b, which was downregulated in A2780TAX and upregulated in the other cell lines. The miR-30c, miR-130a and miR-335 were downregulated in all the resistant cell lines, thereby suggesting a direct involvement in the development of chemoresistance. Finally downstream target validation was proven for the miR-130a, whose downregulation was linked to the translational activation of the M-CSF gene, a known resistance factor for ovarian cancer.
  
  
  CONCLUSIONS
  Our results indicate that ovarian cancer drug resistance is associated with a distinct miRNA fingerprint, and miRNA microarrays could represent a prognostic tool to monitor the chemotherapy outcome.
authors.affiliation: Department of Hematology, Istituto Superiore di Sanità, Rome, Italy. antonio.sorrentino@iss.it
authors.forename: Antonio
authors.initials: A
authors.lastname: Sorrentino
authors.forename: Chang-Gong
authors.initials: CG
authors.lastname: Liu
authors.forename: Antonio
authors.initials: A
authors.lastname: Addario
authors.forename: Cesare
authors.initials: C
authors.lastname: Peschle
authors.forename: Giovanni
authors.initials: G
authors.lastname: Scambia
authors.forename: Cristiano
authors.initials: C
authors.lastname: Ferlini
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D015152:Blotting, Northern; D015153:Blotting, Western; D045744:Cell Line, Tumor; D002945:Cisplatin / Q000494:pharmacology*; D019295:Computational Biology; D019008:Drug Resistance, Neoplasm; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006367:HeLa Cells; D006801:Humans; D016173:Macrophage Colony-Stimulating Factor / Q000096:biosynthesis / Q000235:genetics; D035683:MicroRNAs / Q000096:biosynthesis* / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D010051:Ovarian Neoplasms / Q000188:drug therapy* / Q000235:genetics*; D017239:Paclitaxel / Q000494:pharmacology*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D015854:Up-Regulation
chemical_list: D000970:Antineoplastic Agents; D035683:MicroRNAs; D012333:RNA, Messenger; D016173:Macrophage Colony-Stimulating Factor; D017239:Paclitaxel; D002945:Cisplatin