title: Methylthioadenosine phosphorylase inactivation depends on gene deletion in laryngeal squamous cell carcinoma.
abstract: OBJECTIVE
  Methylthioadenosine phosphorylase (MTAP) is an essential enzyme for the methionine and adenosine salvage pathway in normal cells, frequently inactivated in many different human cancers. MTAP status could be important for tumour cell sensitivity to adjuvant chemotherapy. To our knowledge, there have been no reports to date on MTAP status in laryngeal carcinoma.
  
  
  RESULTS
  A series of 31 laryngeal squamous cell carcinomas was investigated for MTAP mRNA expression using reverse transcription and quantitative polymerase chain reaction (qPCR), as well as for MTAP gene deletion and/or promoter hypermethylation using qPCR and methylation-specific PCR, respectively. Low MTAP mRNA expression was found in 32% of cases, and was associated with MTAP gene deletion (in 70%; P<0.001) but not with MTAP promoter hypermethylation, indicating that, in this tumour, gene deletion is the main mechanism for MTAP inactivation. Neither low mRNA expression nor gene deletion was associated with any of the clinicopathological parameters investigated.
  
  
  CONCLUSIONS
  Given the significance of MTAP status for cell sensitivity to different chemotherapeutic regimens, our results suggest that determination of MTAP inactivation should be taken into consideration in managing laryngeal squamous cell carcinomas.
authors.affiliation: Fundació Clínic per a la Recerca Biomèdica, Barcelona, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Conde
authors.forename: Isabel
authors.initials: I
authors.lastname: Vilaseca
authors.forename: Llucia
authors.initials: L
authors.lastname: Alós
authors.forename: Manuel
authors.initials: M
authors.lastname: Bernal-Sprekelsen
authors.forename: Antonio
authors.initials: A
authors.lastname: Cardesa
authors.forename: Alfons
authors.initials: A
authors.lastname: Nadal
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000235:genetics* / Q000378:metabolism; D019468:Disease Management; D005500:Follow-Up Studies; D017353:Gene Deletion; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D006801:Humans; D053208:Kaplan-Meier Estimate; D007822:Laryngeal Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011683:Purine-Nucleoside Phosphorylase / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D016896:Treatment Outcome
chemical_list: D012333:RNA, Messenger; D011683:Purine-Nucleoside Phosphorylase; C021784:5'-methylthioadenosine phosphorylase