title: DNA repair gene expression level in peripheral blood and tumour tissue from non-small cell lung cancer and head and neck squamous cell cancer patients.
abstract: BACKGROUND
  The nucleotide excision repair pathway is crucial for cellular DNA integrity and the ERCC1 helicase is also potentially involved in resistance to platinum-based chemotherapy, and high levels of ERCC1 mRNA in tumours have been associated with cisplatin resistance in different human cancers. The aim of this work was to investigate the correlation between DNA repair gene expression levels in tumour tissue, normal tissue and peripheral blood samples from patients with two common human cancers, non-small cell lung cancer (NSCLC) and squamous cell carcinoma of the head and neck (HNSCC), to test if blood gene expression could be a proxy for tumour tissue gene expression to predict response to platinum-based chemotherapy.
  
  
  METHODS
  Using RT-qPCR we determined ERCC1, ERCC2, ERCC4, XPA, XPC, XRCC1, XRCC3, APEX, OGG1, MGMT mRNA levels in fresh NSCLC, normal lung and HNSCC tissue, as well as blood, from NSCLC and HNSCC patients who were treated surgically.
  
  
  RESULTS
  Target gene expression in NSCLC and HNSCC tissue was higher than in blood. A statistically significant correlation (p<0.05) was found between target gene mRNA expression in tumour tissue and blood, in particular ERCC1, MGMT, XPC, XRCC1 and XRCC3 in NSCLC and APEX, ERCC1, ERCC2, ERCC4, XRCC1 and XRCC3 in HNSCC.
  
  
  CONCLUSIONS
  The existence of a significant correlation between blood and tumour tissue expression of some genes of clinical interest, such as ERCC1 in NSCLC and HNSCC, could allow the introduction in clinical practice of a simple test that would measure mRNA levels of DNA repair genes in peripheral blood samples instead of tissue samples to determine prognostic and predictive factors in NSCLC and HNSCC patients.
authors.affiliation: SC Oncologia Medica, San Giovanni Battista Hospital, Turin, Italy.
authors.forename: Marina
authors.initials: M
authors.lastname: Schena
authors.forename: Simonetta
authors.initials: S
authors.lastname: Guarrera
authors.forename: Lucio
authors.initials: L
authors.lastname: Buffoni
authors.forename: Angelica
authors.initials: A
authors.lastname: Salvadori
authors.forename: Floriana
authors.initials: F
authors.lastname: Voglino
authors.forename: Alessandra
authors.initials: A
authors.lastname: Allione
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Pecorari
authors.forename: Enrico
authors.initials: E
authors.lastname: Ruffini
authors.forename: Paolo
authors.initials: P
authors.lastname: Garzino-Demo
authors.forename: Sara
authors.initials: S
authors.lastname: Bustreo
authors.forename: Lorena
authors.initials: L
authors.lastname: Consito
authors.forename: Paolo
authors.initials: P
authors.lastname: Bironzo
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Matullo
mesh_terms: D000328:Adult; D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000097:blood / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D004260:DNA Repair / Q000235:genetics*; D045643:DNA Repair Enzymes / Q000097:blood / Q000235:genetics; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006258:Head and Neck Neoplasms / Q000097:blood / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008175:Lung Neoplasms / Q000097:blood / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D018307:Neoplasms, Squamous Cell / Q000097:blood / Q000201:enzymology / Q000235:genetics* / Q000473:pathology
chemical_list: D045643:DNA Repair Enzymes