Deletions of the INK4A gene in superficial bladder tumors: Association with recurrence Journal Article


Authors: Orlow, I.; LaRue, H.; Osman, I.; Lacombe, L.; Moore, L.; Rabbani, F.; Meyer, F.; Fradet, Y.; Cordon-Cardo, C.
Article Title: Deletions of the INK4A gene in superficial bladder tumors: Association with recurrence
Abstract: The INK4A and the INK4B genes map to chromosome 9p21, an area frequently deleted in bladder neoplasms. In addition to the p16 protein, the INK4A encodes for a second product, termed p19(ARF). We analyzed tissues from 121 patients with initial Ta and T1 tumors. Deletions of the INK4A gene were observed in 17 of 121 (14.1%) cases. Point mutations were identified in 2 of 64 (3.1%) tumors. The INK4A-exon 1β and the INK4B gene were codeleted with INK4A in all of the homozygously deleted cases analyzed. The p16 promoter underwent de novo methylation in 7 of 47 (14.9%) evaluable cases. The p16- positive phenotype was observed in 18 of 56 (32%) evaluable cases, p16 negative phenotype correlated with deletion and methylation status. A statistically significant association between INK4A homozygous deletions and tumor size was observed (P = 0.003). Patients bearing tumors with INK4A homozygous deletions had a lower recurrence-free survival (P = 0.040) than those with wild type INK4A. In conclusion, deletions and methylation of the INK4A gene occur frequently in superficial bladder tumors. However, only those deletions that affect both the p16 and the p19(ARF), deregulating both the pRb and p53 pathways, correlated with clinicopathological parameters of worse prognosis.
Keywords: cancer survival; human tissue; unclassified drug; major clinical study; promoter region; exon; gene deletion; histopathology; phenotype; protein p16; tumor volume; chromosome 9p; gene product; dna methylation; bladder tumor; recurrent disease; protein p19; point mutation; prognosis; human; priority journal; article
Journal Title: American Journal of Pathology
Volume: 155
Issue: 1
ISSN: 0002-9440
Publisher: Elsevier Science, Inc.  
Date Published: 1999-07-01
Start Page: 105
End Page: 113
Language: English
PUBMED: 10393843
PROVIDER: scopus
PMCID: PMC1866649
DOI: 10.1016/S0002-9440(10)65105-X
DOI/URL:
Notes: Article -- Export Date: 16 August 2016 -- Source: Scopus
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MSK Authors
  1. Iman Osman
    36 Osman
  2. Farhang Rabbani
    84 Rabbani
  3. Irene Orlow
    247 Orlow