Differential expression of the eukaryotic release factor 3 (eRF3/GSPT1) according to gastric cancer histological types.
BACKGROUND
There are now several lines of evidence to suggest that protein synthesis and translation factors are involved in the regulation of cell proliferation and cancer development.


OBJECTIVE
To investigate gene expression patterns of eukaryotic releasing factor 3 (eRF3) in gastric cancer.


METHODS
RNA was prepared from 25 gastric tumour biopsies and adjacent non-neoplastic mucosa. Real time TaqMan reverse transcription polymerase chain reaction (RT-PCR) was performed to measure the relative gene expression levels. DNA was isolated from tumour and normal tissues and gene dosage was determined by a quantitative real time PCR using SYBR Green dye.


RESULTS
Different histological types of gastric tumours were analysed and nine of the 25 tumours revealed eRF3/GSPT1 overexpression; moreover, eight of the 12 intestinal type carcinomas analysed overexpressed the gene, whereas eRF3/GSPT1 was overexpressed in only one of the 10 diffuse type carcinomas (Kruskal-Wallis Test; p < 0.05). No correlation was found between ploidy and transcript expression levels of eRF3/GSPT1. Overexpression of eRF3/GSPT1 was not associated with increased translation rates because the upregulation of eRF3/GSPT1 did not correlate with increased eRF1 levels.


CONCLUSIONS
Overexpression of eRF3/GSPT1 in intestinal type gastric tumours may lead to an increase in the translation efficiency of specific oncogenic transcripts. Alternatively, eRF3/GSPT1 may be involved in tumorigenesis as a result of its non-translational roles, namely (dis)regulating the cell cycle, apoptosis, or transcription.
Malta-Vacas
J
J
Escola Superior de Tecnologia da Saúde de Lisboa, 1990-096 Lisboa, Portugal.
Aires
C
C
Costa
P
P
Conde
A R
AR
Ramos
S
S
Martins
A P
AP
Monteiro
C
C
Brito
M
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004273:DNA, Neoplasm / Q000235:genetics; D018628:Gene Dosage; D006801:Humans; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D010454:Peptide Termination Factors / Q000235:genetics / Q000378:metabolism*; D012334:RNA, Neoplasm / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000473:pathology; D015854:Up-Regulation
D004273:DNA, Neoplasm; D009363:Neoplasm Proteins; D010454:Peptide Termination Factors; D012334:RNA, Neoplasm; C087971:peptide-chain-release factor 3