title: MicroRNA-375 Suppresses Extracellular Matrix Degradation and Invadopodial Activity in Head and Neck Squamous Cell Carcinoma.
abstract: BACKGROUND
  Head and neck squamous cell carcinoma (HNSCC) is a highly invasive cancer with an association with locoregional recurrence and lymph node metastasis. We have previously reported that low microRNA-375 (miR-375) expression levels correlate with poor patient survival, increased locoregional recurrence, and distant metastasis. Increasing miR-375 expression in HNSCC cell lines to levels found in normal cells results in suppressed invasive properties. HNSCC invasion is mediated in part by invadopodia-associated degradation of the extracellular matrix.
  
  
  OBJECTIVE
  To determine whether elevated miR-375 expression in HNSCC cell lines also affects invadopodia formation and activity.
  
  
  METHODS
  For evaluation of the matrix degradation properties of the HNSCC lines, an invadopodial matrix degradation assay was used. The total protein levels of invadopodia-associated proteins were measured by Western blot analyses. Immunoprecipitation experiments were conducted to evaluate the tyrosine phosphorylation state of cortactin. Human protease arrays were used for the detection of the secreted proteases. Quantitative real time-polymerase chain reaction measurements were used to evaluate the messenger RNA (mRNA) expression of the commonly regulated proteases.
  
  
  RESULTS
  Increased miR-375 expression in HNSCC cells suppresses extracellular matrix degradation and reduces the number of mature invadopodia. Higher miR-375 expression does not reduce cellular levels of selected invadopodia-associated proteins, nor is tyrosine phosphorylation of cortactin altered. However, HNSCC cells with higher miR-375 expression had significant reductions in the mRNA expression levels and secreted levels of specific proteases.
  
  
  CONCLUSIONS
  MicroRNA-375 regulates invadopodia maturation and function potentially by suppressing the expression and secretion of proteases.
authors.forename: Lizandra
authors.initials: L
authors.lastname: Jimenez
authors.forename: Ved P
authors.initials: VP
authors.lastname: Sharma
authors.forename: John
authors.initials: J
authors.lastname: Condeelis
authors.forename: Thomas
authors.initials: T
authors.lastname: Harris
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Ow
authors.forename: Michael B
authors.initials: MB
authors.lastname: Prystowsky
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Childs
authors.affiliation: From the Departments of Pathology (Ms Jimenez and Drs Harris, Ow, Prystowsky, Childs, and Segall) and Anatomy & Structural Biology (Ms Jimenez and Drs Sharma, Condeelis, and Segall), Albert Einstein College of Medicine, Bronx, New York.
authors.forename: Jeffrey E
authors.initials: JE
authors.lastname: Segall
mesh_terms: D015153:Blotting, Western; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D022081:Cell Surface Extensions / Q000378:metabolism*; D051356:Cortactin / Q000378:metabolism; D010450:Endopeptidases / Q000235:genetics* / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic; D006258:Head and Neck Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007610:Kallikreins / Q000235:genetics / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics*; D040081:Protein Array Analysis / Q000379:methods; D011485:Protein Binding; D060066:Protein Interaction Maps / Q000235:genetics; D020543:Proteome / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012697:Serine Endopeptidases
chemical_list: D051356:Cortactin; C540933:MIRN375 microRNA, human; D035683:MicroRNAs; D020543:Proteome; D010450:Endopeptidases; C100936:KLK10 protein, human; C103551:KLK6 protein, human; D007610:Kallikreins; D012697:Serine Endopeptidases; C579270:MMP9 protein, human; D020780:Matrix Metalloproteinase 9