Suppression of Egr-1 expression in human oral squamous carcinoma cells by okadaic acid

Hirohiko Okamura, H. Morimoto, M. Fujita, F. Nasu, E. Sasaki, T. Haneji

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

We examined the expression of early growth response-1 (Egr-1) gene in human oral squamous carcinoma cell lines SCCKN and SCC-25 cells and human osteoblastic cell lines Saos-2 and MG63 cells treated with okadaic acid, a potent inhibitor of protein phosphatases type 1 and type 2A. Western blot analysis revealed that Egr-1 was strongly expressed in SCCKN cells and that okadaic acid decreased the expression of Egr-1 protein in these cells. However, Egr-1 was expressed at lower levels in SCC-25, Saos-2, and MG63 cells and transiently increased with the okadaic acid treatment. Suppression of Egr-1 protein expression in okadaic acid-treated SCCKN cells stemmed from the suppression of the Egr-1 mRNA level, as determined by the RT-RCR method. Formaldehyde-fixed and alcohol-permeabilized cultured SCCKN cells were reacted with the anti-Egr-1 antibody using immunohistochemical methods. Intense fluorescence was observed in the nuclei of the control SCCKN cells interacted with anti-Egr-1 antibody. However, only a weak reaction was observed in the nuclei in SCCKN cells treated with okadaic acid. A gel mobility shift assay showed that treatment of SCCKN cells with okadaic acid suppressed Egr-1 binding to the DIG-labeled Egr-1 consensus oligonucleotide probe. The present results indicate that the alteration of phosphorylation states in SCCKN cells regulates Egr-1 binding to its consensus sequence and its expression at the transcriptional level.

Original languageEnglish
Pages (from-to)779-784
Number of pages6
JournalOral Oncology
Volume38
Issue number8
DOIs
Publication statusPublished - Dec 2002
Externally publishedYes

Fingerprint

Okadaic Acid
Squamous Cell Carcinoma
Growth
Early Growth Response Protein 1
Antibody Formation
Protein Phosphatase 2
Cell Line
Oligonucleotide Probes
Consensus Sequence
Electrophoretic Mobility Shift Assay
Formaldehyde
Cultured Cells
Fluorescence
Western Blotting
Gels
Phosphorylation
Alcohols

Keywords

  • Dephosphorylation
  • Egr-1
  • Okadaic acid
  • Phosphorylation
  • SCCKN cells

ASJC Scopus subject areas

  • Oncology

Cite this

Suppression of Egr-1 expression in human oral squamous carcinoma cells by okadaic acid. / Okamura, Hirohiko; Morimoto, H.; Fujita, M.; Nasu, F.; Sasaki, E.; Haneji, T.

In: Oral Oncology, Vol. 38, No. 8, 12.2002, p. 779-784.

Research output: Contribution to journalArticle

Okamura, Hirohiko ; Morimoto, H. ; Fujita, M. ; Nasu, F. ; Sasaki, E. ; Haneji, T. / Suppression of Egr-1 expression in human oral squamous carcinoma cells by okadaic acid. In: Oral Oncology. 2002 ; Vol. 38, No. 8. pp. 779-784.
@article{2fdeed4eb7bc4cc2b749338751593b09,
title = "Suppression of Egr-1 expression in human oral squamous carcinoma cells by okadaic acid",
abstract = "We examined the expression of early growth response-1 (Egr-1) gene in human oral squamous carcinoma cell lines SCCKN and SCC-25 cells and human osteoblastic cell lines Saos-2 and MG63 cells treated with okadaic acid, a potent inhibitor of protein phosphatases type 1 and type 2A. Western blot analysis revealed that Egr-1 was strongly expressed in SCCKN cells and that okadaic acid decreased the expression of Egr-1 protein in these cells. However, Egr-1 was expressed at lower levels in SCC-25, Saos-2, and MG63 cells and transiently increased with the okadaic acid treatment. Suppression of Egr-1 protein expression in okadaic acid-treated SCCKN cells stemmed from the suppression of the Egr-1 mRNA level, as determined by the RT-RCR method. Formaldehyde-fixed and alcohol-permeabilized cultured SCCKN cells were reacted with the anti-Egr-1 antibody using immunohistochemical methods. Intense fluorescence was observed in the nuclei of the control SCCKN cells interacted with anti-Egr-1 antibody. However, only a weak reaction was observed in the nuclei in SCCKN cells treated with okadaic acid. A gel mobility shift assay showed that treatment of SCCKN cells with okadaic acid suppressed Egr-1 binding to the DIG-labeled Egr-1 consensus oligonucleotide probe. The present results indicate that the alteration of phosphorylation states in SCCKN cells regulates Egr-1 binding to its consensus sequence and its expression at the transcriptional level.",
keywords = "Dephosphorylation, Egr-1, Okadaic acid, Phosphorylation, SCCKN cells",
author = "Hirohiko Okamura and H. Morimoto and M. Fujita and F. Nasu and E. Sasaki and T. Haneji",
year = "2002",
month = "12",
doi = "10.1016/S1368-8375(02)00039-8",
language = "English",
volume = "38",
pages = "779--784",
journal = "Oral Oncology",
issn = "1368-8375",
publisher = "Elsevier Limited",
number = "8",

}

TY - JOUR

T1 - Suppression of Egr-1 expression in human oral squamous carcinoma cells by okadaic acid

AU - Okamura, Hirohiko

AU - Morimoto, H.

AU - Fujita, M.

AU - Nasu, F.

AU - Sasaki, E.

AU - Haneji, T.

PY - 2002/12

Y1 - 2002/12

N2 - We examined the expression of early growth response-1 (Egr-1) gene in human oral squamous carcinoma cell lines SCCKN and SCC-25 cells and human osteoblastic cell lines Saos-2 and MG63 cells treated with okadaic acid, a potent inhibitor of protein phosphatases type 1 and type 2A. Western blot analysis revealed that Egr-1 was strongly expressed in SCCKN cells and that okadaic acid decreased the expression of Egr-1 protein in these cells. However, Egr-1 was expressed at lower levels in SCC-25, Saos-2, and MG63 cells and transiently increased with the okadaic acid treatment. Suppression of Egr-1 protein expression in okadaic acid-treated SCCKN cells stemmed from the suppression of the Egr-1 mRNA level, as determined by the RT-RCR method. Formaldehyde-fixed and alcohol-permeabilized cultured SCCKN cells were reacted with the anti-Egr-1 antibody using immunohistochemical methods. Intense fluorescence was observed in the nuclei of the control SCCKN cells interacted with anti-Egr-1 antibody. However, only a weak reaction was observed in the nuclei in SCCKN cells treated with okadaic acid. A gel mobility shift assay showed that treatment of SCCKN cells with okadaic acid suppressed Egr-1 binding to the DIG-labeled Egr-1 consensus oligonucleotide probe. The present results indicate that the alteration of phosphorylation states in SCCKN cells regulates Egr-1 binding to its consensus sequence and its expression at the transcriptional level.

AB - We examined the expression of early growth response-1 (Egr-1) gene in human oral squamous carcinoma cell lines SCCKN and SCC-25 cells and human osteoblastic cell lines Saos-2 and MG63 cells treated with okadaic acid, a potent inhibitor of protein phosphatases type 1 and type 2A. Western blot analysis revealed that Egr-1 was strongly expressed in SCCKN cells and that okadaic acid decreased the expression of Egr-1 protein in these cells. However, Egr-1 was expressed at lower levels in SCC-25, Saos-2, and MG63 cells and transiently increased with the okadaic acid treatment. Suppression of Egr-1 protein expression in okadaic acid-treated SCCKN cells stemmed from the suppression of the Egr-1 mRNA level, as determined by the RT-RCR method. Formaldehyde-fixed and alcohol-permeabilized cultured SCCKN cells were reacted with the anti-Egr-1 antibody using immunohistochemical methods. Intense fluorescence was observed in the nuclei of the control SCCKN cells interacted with anti-Egr-1 antibody. However, only a weak reaction was observed in the nuclei in SCCKN cells treated with okadaic acid. A gel mobility shift assay showed that treatment of SCCKN cells with okadaic acid suppressed Egr-1 binding to the DIG-labeled Egr-1 consensus oligonucleotide probe. The present results indicate that the alteration of phosphorylation states in SCCKN cells regulates Egr-1 binding to its consensus sequence and its expression at the transcriptional level.

KW - Dephosphorylation

KW - Egr-1

KW - Okadaic acid

KW - Phosphorylation

KW - SCCKN cells

UR - http://www.scopus.com/inward/record.url?scp=0037004193&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0037004193&partnerID=8YFLogxK

U2 - 10.1016/S1368-8375(02)00039-8

DO - 10.1016/S1368-8375(02)00039-8

M3 - Article

VL - 38

SP - 779

EP - 784

JO - Oral Oncology

JF - Oral Oncology

SN - 1368-8375

IS - 8

ER -