title: Immunohistochemical detection of Helicobacter pylori without association of TLR5 expression in oral squamous cell carcinoma.
abstract: BACKGROUND
  Approximately 15% of human deaths from cancer are associated with chronic viral or bacterial infections. Helicobacter pylori (HP), a flagellated, Gram-negative, spiral, microaerophilic bacteria is considered to be the most common chronic bacterial infection in humans. Toll-like receptor 5 (TLR5) is involved in recognition of bacterial flagella and is thought to promote tumour growth through inflammation-dependent mechanisms in epithelial cells.
  
  
  METHODS
  Expression of HP and TLR5 was analysed in OSCC specimen (n = 191) by immunohistochemistry. TLR5 expression specificity was conducted by Western blotting in cancer cell lines (BICR3, BICR56). TLR5-stained sections were scanned and digitally analysed using ImageJ and the immunomembrane plug-in. HP expression and TLR5 expression were associated with clinicopathological characteristics and impact on survival.
  
  
  RESULTS
  Helicobacter pylori detection was significantly associated with recurrence of the tumour, whereas TLR5 expression was not. Multivariate analysis demonstrated HP expression as an independent prognostic factor (P = 0.0260). TLR5 specificity was confirmed by Western blot analysis.
  
  
  CONCLUSIONS
  For the first time, this study provides evidence that immunohistochemically detected HP expression in OSCC is associated with reduced disease-free survival in a large patient cohort. Although TLR5 was not associated with any clinicopathological characteristics or impact on survival, investigation of the TLR family seems to be reasonable due to the possible existence of other pathogenic bacterial or viral compounds in oral cavity cancer.
authors: Department of Oral and Maxillofacial Surgery, University Hospital Tuebingen, Tuebingen, Germany.
authors: Martin
authors: M
authors: Grimm
authors: Adelheid
authors: A
authors: Munz
authors: Alexandros
authors: A
authors: Exarchou
authors: Joachim
authors: J
authors: Polligkeit
authors: Siegmar
authors: S
authors: Reinert
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis; D002294:Carcinoma, Squamous Cell / Q000382:microbiology* / Q000473:pathology / Q000556:secondary; D018929:Cell Culture Techniques; D045744:Cell Line, Tumor; D015331:Cohort Studies; D018572:Disease-Free Survival; D004848:Epithelium / Q000382:microbiology / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D016480:Helicobacter pylori / Q000302:isolation & purification*; D006801:Humans; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009061:Mouth Mucosa / Q000382:microbiology / Q000473:pathology; D009062:Mouth Neoplasms / Q000382:microbiology* / Q000473:pathology; D009364:Neoplasm Recurrence, Local / Q000382:microbiology / Q000473:pathology; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D017154:Stromal Cells / Q000473:pathology; D015996:Survival Rate; D051198:Toll-Like Receptor 5 / Q000032:analysis*
chemical_list: D014408:Biomarkers, Tumor; C495346:TLR5 protein, human; D051198:Toll-Like Receptor 5
keywords: Helicobacter pylori; immunohistochemistry; oral squamous cell carcinoma; toll-like receptor