Abstract
CCAAT element binding protein beta (C/EBPβ) is an important regulator of cell growth, differentiation and in promoting tumor invasiveness. C/EBPβ is located on chromosome 20q, which is amplified in many solid tumors including gastric cancers (GC). We sought to characterize the status of C/EBPβ expression in GCs, which was recently found to repres TFF1 gene. Microarray analysis revealed overexpression of C/EBPβ in 25 of 27 (93%) GC when compared to 12 normal gastric tissue samples. RT-PCR analysis confirmed the overexpression of C/EBPβ transcripts in 54 of 59 (91%) GC. In total, 15 of 18 gastric tumors exhibited at least fivefold higher C/EBPβ transcript levels compared to their corresponding adjacent normal gastric tissue samples. Moreover, immunohistochemistry analysis demonstrated increased nuclear staining of C/EBPβ in 10 of 13 GC and at least fourfold overexpression of C/EBPβ in three primary GC compared to adjacent normal gastric tissue. Furthermore, a striking correlation of decreased TFF1 expression with increased C/EBPβ was observed in the gastric tumors studied. Microarray analysis demonstrated a loss of TFF1 expression in all 27 GC cases examined, of which 25 exhibited high C/EBPβ expression compared to normal gastric tissue. RT-PCR analysis revealed loss of TFF1 expression in 56 of 59 gastric tumors in which 54 of these tumors exhibited overexpression of C/EBPβ. Immunohistochemical analysis revealed overexpression of C/EBPβ in 10 of 13 gastric tumors that exhibited low expression of TFF1 at the protein level. Thus, overexpression of the transcription factor C/EBPβJ in the majority of GCs is a novel finding.
Original language | English |
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Pages (from-to) | 643-649 |
Number of pages | 7 |
Journal | Oncogene |
Volume | 25 |
Issue number | 4 |
DOIs | |
State | Published - 26 Jan 2006 |
Externally published | Yes |
Keywords
- C/EBPβ
- Gastric cancer
- Overexpression
- TFF1