Alterations of the p16INK4a gene in resected nonsmall cell lung tumors and exfoliated cells within sputum

Jung Ta Chen, Yi Chun Chen, Yu Chien Wang, Ruo Chia Tseng, Chih Yi Chen, Yi-Ching Wang

Research output: Contribution to journalArticle

46 Citations (Scopus)

Abstract

Recently, we reported that p16 protein expression was nondetectable in 49.5% of 107 resected nonsmall cell lung cancers (NSCLCs), suggesting that the p16INK4a gene is frequently inactivated in primary NSCLC. To identify the molecular basis for this p16 immunohistochemical negativity further, we performed a genetic and epigenetic study of p16INK4a status in a series of 115 NSCLC samples parallel to the clinicopathologic and prognostic analyses. Microdissected tumor DNA samples were screened for homozygous deletion using comparative multiplex-polymerase chain reaction (PCR), for intragenic mutation using direct sequencing and for loss of heterozygosity (LOH) using an intragenic microsatellite marker, D9S942. Of these samples, 67 were further analyzed by Smal-based PCR methylation assay to evaluate aberrant methylation at the gene. To examine the correlation of aberrant methylation in tumor and sputum samples, sputum samples from 12 matched patients were assessed for this change. We found that methylation of the p16INK4a gene was present in 38 of the 67 (56.7%) tumors and was significantly associated with negative p 16 protein expression (p = 0.029). A 92% (11/12) concordance of sputum samples with matched resected tumors was found. The survival rates among adenocarcinoma patients with p16INK4a methylation were lower, but at a level of borderline significance compared with those patients without methylation (p = 0.071). In addition, 29.4% of the informative cases were found to harbor LOH at D9S942. None of the 115 microdissected tumors exhibited homozygous deletion in the p16INK4a gene. Only 1 patient exhibited a complex mutation at the fourth ankyrin repeat consensus sequence and concordantly demonstrated p16 immunohistochemical negativity. Overall, 69% (79/115) of NSCLC tumors had at least 1 type of p16INK4a alteration. Our data provide compelling evidence that p16INK4a alterations are involved in NSCLC tumorigenesis and that promoter methylation is the predominant mechanism in p16INK4a deregulation.

Original languageEnglish
Pages (from-to)724-731
Number of pages8
JournalInternational Journal of Cancer
Volume98
Issue number5
DOIs
Publication statusPublished - 2002 Apr 10

Fingerprint

p16 Genes
Sputum
Methylation
Non-Small Cell Lung Carcinoma
Lung
Neoplasms
Loss of Heterozygosity
Ankyrin Repeat
Mutation
Multiplex Polymerase Chain Reaction
Consensus Sequence
Epigenomics
Microsatellite Repeats
Carcinogenesis
Proteins
Adenocarcinoma
Survival Rate
Polymerase Chain Reaction
DNA

All Science Journal Classification (ASJC) codes

  • Oncology
  • Cancer Research

Cite this

Chen, Jung Ta ; Chen, Yi Chun ; Wang, Yu Chien ; Tseng, Ruo Chia ; Chen, Chih Yi ; Wang, Yi-Ching. / Alterations of the p16INK4a gene in resected nonsmall cell lung tumors and exfoliated cells within sputum. In: International Journal of Cancer. 2002 ; Vol. 98, No. 5. pp. 724-731.
@article{b3abfb69299241ed90bd7e370531579f,
title = "Alterations of the p16INK4a gene in resected nonsmall cell lung tumors and exfoliated cells within sputum",
abstract = "Recently, we reported that p16 protein expression was nondetectable in 49.5{\%} of 107 resected nonsmall cell lung cancers (NSCLCs), suggesting that the p16INK4a gene is frequently inactivated in primary NSCLC. To identify the molecular basis for this p16 immunohistochemical negativity further, we performed a genetic and epigenetic study of p16INK4a status in a series of 115 NSCLC samples parallel to the clinicopathologic and prognostic analyses. Microdissected tumor DNA samples were screened for homozygous deletion using comparative multiplex-polymerase chain reaction (PCR), for intragenic mutation using direct sequencing and for loss of heterozygosity (LOH) using an intragenic microsatellite marker, D9S942. Of these samples, 67 were further analyzed by Smal-based PCR methylation assay to evaluate aberrant methylation at the gene. To examine the correlation of aberrant methylation in tumor and sputum samples, sputum samples from 12 matched patients were assessed for this change. We found that methylation of the p16INK4a gene was present in 38 of the 67 (56.7{\%}) tumors and was significantly associated with negative p 16 protein expression (p = 0.029). A 92{\%} (11/12) concordance of sputum samples with matched resected tumors was found. The survival rates among adenocarcinoma patients with p16INK4a methylation were lower, but at a level of borderline significance compared with those patients without methylation (p = 0.071). In addition, 29.4{\%} of the informative cases were found to harbor LOH at D9S942. None of the 115 microdissected tumors exhibited homozygous deletion in the p16INK4a gene. Only 1 patient exhibited a complex mutation at the fourth ankyrin repeat consensus sequence and concordantly demonstrated p16 immunohistochemical negativity. Overall, 69{\%} (79/115) of NSCLC tumors had at least 1 type of p16INK4a alteration. Our data provide compelling evidence that p16INK4a alterations are involved in NSCLC tumorigenesis and that promoter methylation is the predominant mechanism in p16INK4a deregulation.",
author = "Chen, {Jung Ta} and Chen, {Yi Chun} and Wang, {Yu Chien} and Tseng, {Ruo Chia} and Chen, {Chih Yi} and Yi-Ching Wang",
year = "2002",
month = "4",
day = "10",
doi = "10.1002/ijc.10262",
language = "English",
volume = "98",
pages = "724--731",
journal = "International Journal of Cancer",
issn = "0020-7136",
publisher = "Wiley-Liss Inc.",
number = "5",

}

Alterations of the p16INK4a gene in resected nonsmall cell lung tumors and exfoliated cells within sputum. / Chen, Jung Ta; Chen, Yi Chun; Wang, Yu Chien; Tseng, Ruo Chia; Chen, Chih Yi; Wang, Yi-Ching.

In: International Journal of Cancer, Vol. 98, No. 5, 10.04.2002, p. 724-731.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Alterations of the p16INK4a gene in resected nonsmall cell lung tumors and exfoliated cells within sputum

AU - Chen, Jung Ta

AU - Chen, Yi Chun

AU - Wang, Yu Chien

AU - Tseng, Ruo Chia

AU - Chen, Chih Yi

AU - Wang, Yi-Ching

PY - 2002/4/10

Y1 - 2002/4/10

N2 - Recently, we reported that p16 protein expression was nondetectable in 49.5% of 107 resected nonsmall cell lung cancers (NSCLCs), suggesting that the p16INK4a gene is frequently inactivated in primary NSCLC. To identify the molecular basis for this p16 immunohistochemical negativity further, we performed a genetic and epigenetic study of p16INK4a status in a series of 115 NSCLC samples parallel to the clinicopathologic and prognostic analyses. Microdissected tumor DNA samples were screened for homozygous deletion using comparative multiplex-polymerase chain reaction (PCR), for intragenic mutation using direct sequencing and for loss of heterozygosity (LOH) using an intragenic microsatellite marker, D9S942. Of these samples, 67 were further analyzed by Smal-based PCR methylation assay to evaluate aberrant methylation at the gene. To examine the correlation of aberrant methylation in tumor and sputum samples, sputum samples from 12 matched patients were assessed for this change. We found that methylation of the p16INK4a gene was present in 38 of the 67 (56.7%) tumors and was significantly associated with negative p 16 protein expression (p = 0.029). A 92% (11/12) concordance of sputum samples with matched resected tumors was found. The survival rates among adenocarcinoma patients with p16INK4a methylation were lower, but at a level of borderline significance compared with those patients without methylation (p = 0.071). In addition, 29.4% of the informative cases were found to harbor LOH at D9S942. None of the 115 microdissected tumors exhibited homozygous deletion in the p16INK4a gene. Only 1 patient exhibited a complex mutation at the fourth ankyrin repeat consensus sequence and concordantly demonstrated p16 immunohistochemical negativity. Overall, 69% (79/115) of NSCLC tumors had at least 1 type of p16INK4a alteration. Our data provide compelling evidence that p16INK4a alterations are involved in NSCLC tumorigenesis and that promoter methylation is the predominant mechanism in p16INK4a deregulation.

AB - Recently, we reported that p16 protein expression was nondetectable in 49.5% of 107 resected nonsmall cell lung cancers (NSCLCs), suggesting that the p16INK4a gene is frequently inactivated in primary NSCLC. To identify the molecular basis for this p16 immunohistochemical negativity further, we performed a genetic and epigenetic study of p16INK4a status in a series of 115 NSCLC samples parallel to the clinicopathologic and prognostic analyses. Microdissected tumor DNA samples were screened for homozygous deletion using comparative multiplex-polymerase chain reaction (PCR), for intragenic mutation using direct sequencing and for loss of heterozygosity (LOH) using an intragenic microsatellite marker, D9S942. Of these samples, 67 were further analyzed by Smal-based PCR methylation assay to evaluate aberrant methylation at the gene. To examine the correlation of aberrant methylation in tumor and sputum samples, sputum samples from 12 matched patients were assessed for this change. We found that methylation of the p16INK4a gene was present in 38 of the 67 (56.7%) tumors and was significantly associated with negative p 16 protein expression (p = 0.029). A 92% (11/12) concordance of sputum samples with matched resected tumors was found. The survival rates among adenocarcinoma patients with p16INK4a methylation were lower, but at a level of borderline significance compared with those patients without methylation (p = 0.071). In addition, 29.4% of the informative cases were found to harbor LOH at D9S942. None of the 115 microdissected tumors exhibited homozygous deletion in the p16INK4a gene. Only 1 patient exhibited a complex mutation at the fourth ankyrin repeat consensus sequence and concordantly demonstrated p16 immunohistochemical negativity. Overall, 69% (79/115) of NSCLC tumors had at least 1 type of p16INK4a alteration. Our data provide compelling evidence that p16INK4a alterations are involved in NSCLC tumorigenesis and that promoter methylation is the predominant mechanism in p16INK4a deregulation.

UR - http://www.scopus.com/inward/record.url?scp=0037051666&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0037051666&partnerID=8YFLogxK

U2 - 10.1002/ijc.10262

DO - 10.1002/ijc.10262

M3 - Article

C2 - 11920642

AN - SCOPUS:0037051666

VL - 98

SP - 724

EP - 731

JO - International Journal of Cancer

JF - International Journal of Cancer

SN - 0020-7136

IS - 5

ER -