Increased heparanase expression is caused by promoter hypomethylation and up-regulation of transcriptional factor early growth response-1 in human prostate cancer.

Abstract

PURPOSE:

Heparanase degrades heparan sulfate and has been implicated in tumor invasion and metastasis. The transcription factor, early growth response 1 (EGR1), is associated with the inducible transcription of the heparanase gene. We hypothesize that CpG hypomethylation in the heparanase promoter coupled with up-regulation of EGR1 levels may induce heparanase expression in human prostate cancer.

EXPERIMENTAL DESIGN:

Cultured prostate cancer cell lines (Du145, DuPro, LNCaP, and PC-3) with and without 5'-aza-2-deoxycytidine treatment, 177 prostate cancer samples, and 69 benign prostatic hyperplasia (BPH) samples were used. The frequency and level of heparanase promoter methylation were analyzed by methylation-specific primers which covered the core binding motif of EGR1 (GGCG) or SP1 (GGGCGG) or both.

RESULTS:

In cultured Du145, DuPro, LNCaP, and PC-3 cell lines, mRNA transcripts of heparanase were significantly increased after 5'-aza-2-deoxycytidine treatment, suggesting that promoter methylation was involved in the regulation of heparanase mRNA transcript. Significantly higher methylation was found in BPH samples than in prostate cancer samples (P < 0.0001), whereas mRNA transcripts of the heparanase gene were inversely lower in BPH samples than in prostate cancer samples (P < 0.01). EGR1 expression in prostate cancer tissues was significantly higher than in BPH tissues (P < 0.001) and correlated with heparanase expression (P < 0.0001). Moreover, multiple regression analysis revealed that up-regulation of EGR1 contributed significantly more to heparanase expression than did promoter CpG hypomethylation in prostate cancer samples (P < 0.0001).

CONCLUSIONS:

To our knowledge this is the first comprehensive study demonstrating that increased heparanase expression in prostate cancer tissues is due to promoter hypomethylation and up-regulation of transcription factor EGR1.

• Authors: Tatsuya Ogishima, Hiroaki Shiina, Julia E Breault, Laura Tabatabai, William W Bassett, Hideki Enokida, Long-Cheng Li, Toshifumi Kawakami, Shinji Urakami, Leopoldo A Ribeiro-Filho, Masaharu Terashima, Makoto Fujime, Mikio Igawa, Rajvir Dahiya
• Journal: Clinical cancer research : an official journal of the American Association for Cancer Research (Clin Cancer Res) Vol. 11 Issue 3 Pg. 1028-36 (Feb 01 2005) ISSN: 1078-0432 [Print] United States
• PMID: 15709168 (Publication Type: Comparative Study, Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, U.S. Gov't, P.H.S.)

Chemical References

• DNA-Binding Proteins
• EGR1 protein, human
• Early Growth Response Protein 1
• Enzyme Inhibitors
• Immediate-Early Proteins
• RNA, Messenger
• Transcription Factors
• Decitabine
• DNA Modification Methylases
• heparanase
• Glucuronidase
• Azacitidine

Topics

• Aged
• Aged, 80 and over
• Azacitidine (analogs & derivatives, pharmacology)
• Base Sequence
• Cell Line, Tumor
• CpG Islands (genetics)
• DNA Methylation
• DNA Modification Methylases (antagonists & inhibitors)
• DNA-Binding Proteins (genetics)
• Decitabine
• Early Growth Response Protein 1
• Enzyme Inhibitors (pharmacology)
• Gene Expression Regulation, Enzymologic (drug effects)
• Gene Expression Regulation, Neoplastic (drug effects)
• Glucuronidase (genetics)
• Humans
• Immediate-Early Proteins (genetics)
• Male
• Middle Aged
• Promoter Regions, Genetic (genetics)
• Prostatic Hyperplasia (enzymology, genetics, pathology)
• Prostatic Neoplasms (enzymology, genetics, pathology)
• RNA, Messenger (genetics, metabolism)
• Regression Analysis
• Reverse Transcriptase Polymerase Chain Reaction
• Sequence Analysis, DNA
• Transcription Factors (genetics)
• Up-Regulation (genetics)