title: Death-associated protein kinase (DAP kinase) alteration in soft tissue leiomyosarcoma: Promoter methylation or homozygous deletion is associated with a loss of DAP kinase expression.
abstract: The death-associated protein kinase (DAP kinase) was initially identified as a positive mediator of programmed cell death induced by interferon-gamma. To investigate the potential role and the alteration of the DAP kinase gene in soft tissue leiomyosarcoma (LMS), we first searched for homozygous deletion and promoter hypermethylation in 45 LMSs for which genomic DNA was available, using differential PCR and methylation-specific PCR, respectively. Promoter methylation was recognized in 10 of 45 cases (22%), and homozygous deletion was detected in 3 of 45 cases (7%). p53 mutation was detected in 11 of 45 LMS cases (24%). Cases with DAP kinase alteration or p53 mutation showed a close correlation with high French Federation of Cancer Centers grade or with poor prognosis (P = 0.0244, P = 0.0491, respectively). Next, to determine that DAP kinase promoter methylation or homozygous deletion is involved in the down-regulation of DAP kinase expression, we examined the expression of DAP kinase protein by immunohistochemistry. Decreased expression of DAP kinase protein was recognized in 13 of 45 LMS cases (29%). Seven of 13 cases (54%) with decreased expression of DAP kinase protein revealed promoter methylation or homozygous deletion of DAP kinase, and the methylation status or homozygous deletion of its gene showed a close correlation with decreased DAP kinase expression (P = 0.0300). In conclusion, although DAP kinase alteration was relatively rare, DAP kinase alteration and/or p53 mutation may associate with tumor progression in soft-tissue LMSs. Furthermore, although further detailed analyses are necessary, promoter methylation or homozygous deletion status of DAP kinase may present a major alternative mechanism of a loss of or decrease in DAP kinase expression.
authors.affiliation: Department of Anatomic Pathology, Pathological Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Kawaguchi
authors.forename: Yoshinao
authors.initials: Y
authors.lastname: Oda
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Saito
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Tomonari
authors.initials: T
authors.lastname: Takahira
authors.forename: Sadafumi
authors.initials: S
authors.lastname: Tamiya
authors.forename: Yukihide
authors.initials: Y
authors.lastname: Iwamoto
authors.forename: Masazumi
authors.initials: M
authors.lastname: Tsuneyoshi
mesh_terms: D000328:Adult; D000368:Aged; D051017:Apoptosis Regulatory Proteins; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000235:genetics*; D019175:DNA Methylation; D064550:Death-Associated Protein Kinases; D005260:Female; D017353:Gene Deletion; D016158:Genes, p53; D006801:Humans; D007150:Immunohistochemistry; D007890:Leiomyosarcoma / Q000235:genetics* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D018807:Polymorphism, Single-Stranded Conformational; D011401:Promoter Regions, Genetic; D012983:Soft Tissue Neoplasms / Q000235:genetics* / Q000473:pathology
chemical_list: D051017:Apoptosis Regulatory Proteins; D064550:Death-Associated Protein Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases