Frequent epigenetic inactivation of RASSF1A in human bladder carcinoma

M. G. Lee, H. Y. Kim, D. S. Byun, S. J. Lee, C. H. Lee, J. Kim, S. G. Chang, Sung-Gil Chi

Research output: Contribution to journalArticle

146 Citations (Scopus)

Abstract

Allelie deletion or transcriptional silencing of RASSF1, a putative tumor suppressor at 3p21.3, has been found in a considerable proportion of lung, breast, and ovarian cancers. In this study, we analyzed the expression and mutation status of three RASSF1 isoforms (-A, -B, and -C) in 55 primary bladder carcinomas and 10 bladder and prostate cancer cell lines. The RASSF1A transcript was not found in 80% (4 of 5) and 100% (4 of 4) of bladder and prostate cell lines, respectively. Compared with normal bladder tissues, loss or significant reduction of RASSF1A was identified in 62% (34 of 55) of primary bladder carcinomas and 10 (83%) of 12 matched sets showed tumor-specific alteration of RASSF1A expression. Moreover, loss or abnormal down-regulation of RASSF1A correlated with advanced tumor stage. RASSF1B was undetectable in 60% (3 of 5) of bladder cell lines and in 31% (17 of 55) of primary tumors, but none of these tumors showed altered expression exclusively in RASSF1B. RASSF1C transcript was detected in all cell lines and primary tumors we examined. Expression of RASSF1A and RASSF1B was reactivated in all nonexpressor cell lines by treatment with the demethylating agent 5-aza-2′-deoxycytidine. Bisulfite DNA sequencing analysis revealed that aberrant hypermethylation at the CpG island in the RASSF1A promoter is strongly associated with the loss of RASSF1A expression in cell lines and uncultured primary tumors. Methylation-specific PCR and BstUI digestion analyses also demonstrated that 97% (33 of 34) of RASSF1A-nonexpressing primary tumors are methylated. Although somatic mutations were not identified in RASSF1 transcripts expressed in unmethylated tumors, 24% (9 of 37) of methylated cell lines and primary tumors showed detectable reductions in genomic levels of RASSF1, suggesting that RASSF1A inactivation might be caused by both epigenetic and genetic mechanisms in a subset of bladder tumors. Together, our data suggest that RASSF1A inactivation may play a critical role in the malignant progression of human bladder carcinomas.

Original languageEnglish
Pages (from-to)6688-6692
Number of pages5
JournalCancer Research
Volume61
Issue number18
Publication statusPublished - 2001 Sep 15
Externally publishedYes

Fingerprint

Epigenomics
Urinary Bladder
Carcinoma
Neoplasms
Cell Line
decitabine
Tumor Cell Line
Urinary Bladder Neoplasms
Mutation
CpG Islands
DNA Sequence Analysis
Ovarian Neoplasms
Methylation
Prostate
Digestion
Lung Neoplasms
Prostatic Neoplasms
Protein Isoforms
Down-Regulation
Breast Neoplasms

ASJC Scopus subject areas

  • Cancer Research
  • Oncology

Cite this

Lee, M. G., Kim, H. Y., Byun, D. S., Lee, S. J., Lee, C. H., Kim, J., ... Chi, S-G. (2001). Frequent epigenetic inactivation of RASSF1A in human bladder carcinoma. Cancer Research, 61(18), 6688-6692.

Frequent epigenetic inactivation of RASSF1A in human bladder carcinoma. / Lee, M. G.; Kim, H. Y.; Byun, D. S.; Lee, S. J.; Lee, C. H.; Kim, J.; Chang, S. G.; Chi, Sung-Gil.

In: Cancer Research, Vol. 61, No. 18, 15.09.2001, p. 6688-6692.

Research output: Contribution to journalArticle

Lee, MG, Kim, HY, Byun, DS, Lee, SJ, Lee, CH, Kim, J, Chang, SG & Chi, S-G 2001, 'Frequent epigenetic inactivation of RASSF1A in human bladder carcinoma', Cancer Research, vol. 61, no. 18, pp. 6688-6692.
Lee MG, Kim HY, Byun DS, Lee SJ, Lee CH, Kim J et al. Frequent epigenetic inactivation of RASSF1A in human bladder carcinoma. Cancer Research. 2001 Sep 15;61(18):6688-6692.
Lee, M. G. ; Kim, H. Y. ; Byun, D. S. ; Lee, S. J. ; Lee, C. H. ; Kim, J. ; Chang, S. G. ; Chi, Sung-Gil. / Frequent epigenetic inactivation of RASSF1A in human bladder carcinoma. In: Cancer Research. 2001 ; Vol. 61, No. 18. pp. 6688-6692.
@article{ef0fd41050bb412d85d64f27e20b11cd,
title = "Frequent epigenetic inactivation of RASSF1A in human bladder carcinoma",
abstract = "Allelie deletion or transcriptional silencing of RASSF1, a putative tumor suppressor at 3p21.3, has been found in a considerable proportion of lung, breast, and ovarian cancers. In this study, we analyzed the expression and mutation status of three RASSF1 isoforms (-A, -B, and -C) in 55 primary bladder carcinomas and 10 bladder and prostate cancer cell lines. The RASSF1A transcript was not found in 80{\%} (4 of 5) and 100{\%} (4 of 4) of bladder and prostate cell lines, respectively. Compared with normal bladder tissues, loss or significant reduction of RASSF1A was identified in 62{\%} (34 of 55) of primary bladder carcinomas and 10 (83{\%}) of 12 matched sets showed tumor-specific alteration of RASSF1A expression. Moreover, loss or abnormal down-regulation of RASSF1A correlated with advanced tumor stage. RASSF1B was undetectable in 60{\%} (3 of 5) of bladder cell lines and in 31{\%} (17 of 55) of primary tumors, but none of these tumors showed altered expression exclusively in RASSF1B. RASSF1C transcript was detected in all cell lines and primary tumors we examined. Expression of RASSF1A and RASSF1B was reactivated in all nonexpressor cell lines by treatment with the demethylating agent 5-aza-2′-deoxycytidine. Bisulfite DNA sequencing analysis revealed that aberrant hypermethylation at the CpG island in the RASSF1A promoter is strongly associated with the loss of RASSF1A expression in cell lines and uncultured primary tumors. Methylation-specific PCR and BstUI digestion analyses also demonstrated that 97{\%} (33 of 34) of RASSF1A-nonexpressing primary tumors are methylated. Although somatic mutations were not identified in RASSF1 transcripts expressed in unmethylated tumors, 24{\%} (9 of 37) of methylated cell lines and primary tumors showed detectable reductions in genomic levels of RASSF1, suggesting that RASSF1A inactivation might be caused by both epigenetic and genetic mechanisms in a subset of bladder tumors. Together, our data suggest that RASSF1A inactivation may play a critical role in the malignant progression of human bladder carcinomas.",
author = "Lee, {M. G.} and Kim, {H. Y.} and Byun, {D. S.} and Lee, {S. J.} and Lee, {C. H.} and J. Kim and Chang, {S. G.} and Sung-Gil Chi",
year = "2001",
month = "9",
day = "15",
language = "English",
volume = "61",
pages = "6688--6692",
journal = "Cancer Research",
issn = "0008-5472",
publisher = "American Association for Cancer Research Inc.",
number = "18",

}

TY - JOUR

T1 - Frequent epigenetic inactivation of RASSF1A in human bladder carcinoma

AU - Lee, M. G.

AU - Kim, H. Y.

AU - Byun, D. S.

AU - Lee, S. J.

AU - Lee, C. H.

AU - Kim, J.

AU - Chang, S. G.

AU - Chi, Sung-Gil

PY - 2001/9/15

Y1 - 2001/9/15

N2 - Allelie deletion or transcriptional silencing of RASSF1, a putative tumor suppressor at 3p21.3, has been found in a considerable proportion of lung, breast, and ovarian cancers. In this study, we analyzed the expression and mutation status of three RASSF1 isoforms (-A, -B, and -C) in 55 primary bladder carcinomas and 10 bladder and prostate cancer cell lines. The RASSF1A transcript was not found in 80% (4 of 5) and 100% (4 of 4) of bladder and prostate cell lines, respectively. Compared with normal bladder tissues, loss or significant reduction of RASSF1A was identified in 62% (34 of 55) of primary bladder carcinomas and 10 (83%) of 12 matched sets showed tumor-specific alteration of RASSF1A expression. Moreover, loss or abnormal down-regulation of RASSF1A correlated with advanced tumor stage. RASSF1B was undetectable in 60% (3 of 5) of bladder cell lines and in 31% (17 of 55) of primary tumors, but none of these tumors showed altered expression exclusively in RASSF1B. RASSF1C transcript was detected in all cell lines and primary tumors we examined. Expression of RASSF1A and RASSF1B was reactivated in all nonexpressor cell lines by treatment with the demethylating agent 5-aza-2′-deoxycytidine. Bisulfite DNA sequencing analysis revealed that aberrant hypermethylation at the CpG island in the RASSF1A promoter is strongly associated with the loss of RASSF1A expression in cell lines and uncultured primary tumors. Methylation-specific PCR and BstUI digestion analyses also demonstrated that 97% (33 of 34) of RASSF1A-nonexpressing primary tumors are methylated. Although somatic mutations were not identified in RASSF1 transcripts expressed in unmethylated tumors, 24% (9 of 37) of methylated cell lines and primary tumors showed detectable reductions in genomic levels of RASSF1, suggesting that RASSF1A inactivation might be caused by both epigenetic and genetic mechanisms in a subset of bladder tumors. Together, our data suggest that RASSF1A inactivation may play a critical role in the malignant progression of human bladder carcinomas.

AB - Allelie deletion or transcriptional silencing of RASSF1, a putative tumor suppressor at 3p21.3, has been found in a considerable proportion of lung, breast, and ovarian cancers. In this study, we analyzed the expression and mutation status of three RASSF1 isoforms (-A, -B, and -C) in 55 primary bladder carcinomas and 10 bladder and prostate cancer cell lines. The RASSF1A transcript was not found in 80% (4 of 5) and 100% (4 of 4) of bladder and prostate cell lines, respectively. Compared with normal bladder tissues, loss or significant reduction of RASSF1A was identified in 62% (34 of 55) of primary bladder carcinomas and 10 (83%) of 12 matched sets showed tumor-specific alteration of RASSF1A expression. Moreover, loss or abnormal down-regulation of RASSF1A correlated with advanced tumor stage. RASSF1B was undetectable in 60% (3 of 5) of bladder cell lines and in 31% (17 of 55) of primary tumors, but none of these tumors showed altered expression exclusively in RASSF1B. RASSF1C transcript was detected in all cell lines and primary tumors we examined. Expression of RASSF1A and RASSF1B was reactivated in all nonexpressor cell lines by treatment with the demethylating agent 5-aza-2′-deoxycytidine. Bisulfite DNA sequencing analysis revealed that aberrant hypermethylation at the CpG island in the RASSF1A promoter is strongly associated with the loss of RASSF1A expression in cell lines and uncultured primary tumors. Methylation-specific PCR and BstUI digestion analyses also demonstrated that 97% (33 of 34) of RASSF1A-nonexpressing primary tumors are methylated. Although somatic mutations were not identified in RASSF1 transcripts expressed in unmethylated tumors, 24% (9 of 37) of methylated cell lines and primary tumors showed detectable reductions in genomic levels of RASSF1, suggesting that RASSF1A inactivation might be caused by both epigenetic and genetic mechanisms in a subset of bladder tumors. Together, our data suggest that RASSF1A inactivation may play a critical role in the malignant progression of human bladder carcinomas.

UR - http://www.scopus.com/inward/record.url?scp=0035884193&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0035884193&partnerID=8YFLogxK

M3 - Article

VL - 61

SP - 6688

EP - 6692

JO - Cancer Research

JF - Cancer Research

SN - 0008-5472

IS - 18

ER -