[Detection of tumor cells in peripheral blood of patients with gastric cancer using mRNA of MAGE genes as markers].
OBJECTIVE
To develop a sensitive and specific RT-PCR assay using the mRNA of MAGE-1 and MAGE-3 genes as specific tumor markers for the detection of the tumor cells in the peripheral blood of patients with gastric cancer.


METHODS
Peripheral blood was obtained from 40 patients with gastric cancer and from 20 healthy volunteers. The mRNA of MAGE-1 and MAGE-3 genes in the peripheral blood mononuclear cells (PBMC) was detected by RT-PCR. The expressions of MAGE-1 and MAGE-3 mRNA in the tumor tissues of these gastric cancer patients were also detected by RT-PCR. Meanwhile,CEA expression by nested RT-PCR in PBMC of 40 gastric cancer patients was also detected.


RESULTS
Of 40 gastric cancer patients, MAGE-1 and MAGE-3 mRNA were positive in 47.5% (19/40) and 25% (10/40) of PBMC respectively, and in 62.5% (25/40) and 30% (12/40) of gastric cancer tissues respectively. As a whole, in the PBMC of 40 gastric cancer patients, 25 (62.5%) samples were found to express at least one type of MAGE mRNA. In the patients whose tumors did not express MAGE-1 and/or MAGE-3 genes, the corresponding MAGE mRNA was also undetected in their PBMC. There was no expression of MAGE-1 or MAGE-3 gene in the PBMC from the 20 healthy donors. The positive rate of MAGE mRNA in PBMC was closely correlated with the tumor stage and lymph node metastasis (P <0.05). Positive rate of CEA gene expression was 32.5% (13/40) in the PBMC of 40 gastric cancer patients, 29 (72.5%)samples were detected to express at least one type of MAGE gene and CEA gene mRNA.


CONCLUSIONS
MAGE-1, MAGE-3 and CEA mRNA are specifically detected with high percentage in the PBMC of gastric cancer patients by RT-PCR. They could be used as specific tumor markers for the detection of the circulating gastric cancer cells, and the detection results may be helpful to evaluate the prognosis of gastric cancer patients.
Wang
Wan-xiang
WX
Department of General Surgery, The Affiliated Hospital of Inner Mongolia Medical College, Huhhot 010050, China. doctorwwx@yahoo.com.cn
Li
Ying-bin
YB
Xie
Xiao-liang
XL
Shu
Xiu-lan
XL
Ouyang
Xiao-hui
XH
D000328:Adult; D000368:Aged; D000951:Antigens, Neoplasm / Q000097:blood* / Q000235:genetics; D014408:Biomarkers, Tumor / Q000097:blood*; D002272:Carcinoembryonic Antigen / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D058950:Melanoma-Specific Antigens; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000097:blood* / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D012680:Sensitivity and Specificity; D013274:Stomach Neoplasms / Q000097:blood* / Q000235:genetics / Q000473:pathology
D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen; C072011:MAGEA1 protein, human; C072013:MAGEA3 protein, human; D058950:Melanoma-Specific Antigens; D009363:Neoplasm Proteins; D012333:RNA, Messenger