title: [Chemotherapy with paclitaxel leads to microRNA release].
abstract: BACKGROUND
  During recent years, microRNAs (Greek: micros = small; miRNA) have become more important. miRNAs are highly conserved, noncoding, single-stranded RNA molecules 17–28 nucleotide in length. Secreted by tumor cells, miRNAs regulate many biological processes and are also involved in chemoresistance. Classical forms of cancer treatment lead to miRNA release. Which miRNAs are correlated to head and neck squamous cell carcinomas (HNSCC) and their chemoresistance to paclitaxel remains unknown.
  
  
  OBJECTIVE
  Identification of miRNAs expressed in HNSCC and elucidation of those involved in conferring chemoresistance to paclitaxel.
  
  
  METHODS
  To identify changes in gene expression, HNSCC cell lines were treated with 10 μM paclitaxel for 48 h and analyzed by microarray analysis. Thereafter, changed in expression of single miRNAs (miR221*, miR222 and miR222*) following paclitaxel treatment were analyzed using a quantitative real-time polymerase chain reaction (qRT-PCR).
  
  
  RESULTS
  Under treatment with paclitaxel, miRNAs were released. The dominant change is upregulation of MIR222 gene expression. Regulation of miR222* expression under paclitaxel treatment seems to be different in human papillomavirus (HPV)-negative and HPV-positive HNSCC cell lines.
  
  
  CONCLUSIONS
  Expression of mirR221/222 is correlated to cell cycle regulation, carcinogenesis, and chemoresistance. Detailed knowledge of the molecular mechanisms and effects ofmiRNAs is important for identifying miRNAs as cancermarkers, as well as for increasing the efficiency of cancer therapeutics.
authors.affiliation: Klinik und Poliklinik für Hals-, Nasen- und Ohrenheilkunde, Universitätsklinikum Schleswig-Holstein, Campus Lübeck, Lübeck, Germany
authors.forename: R
authors.initials: R
authors.lastname: Maushagen
authors.forename: R
authors.initials: R
authors.lastname: Pries
authors.forename: B
authors.initials: B
authors.lastname: Wollenberg
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D019008:Drug Resistance, Neoplasm; D004358:Drug Therapy / Q000379:methods; D006258:Head and Neck Neoplasms / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D035683:MicroRNAs / Q000096:biosynthesis*; D017239:Paclitaxel / Q000008:administration & dosage*; D000077195:Squamous Cell Carcinoma of Head and Neck; D016896:Treatment Outcome
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D035683:MicroRNAs; D017239:Paclitaxel; C525709:MIR221, human; C525710:MIR222, human