Comparison of gene expression profiles between primary tumor and metastatic lesions in gastric cancer patients using laser microdissection and cDNA microarray.
OBJECTIVE
To study the differential gene expression profiles of target cells in primary gastric cancer and its metastatic lymph nodes using laser microdissection (LMD) in combination with cDNA microarray.


METHODS
Normal gastric tissue samples from 30 healthy individuals, 36 cancer tissue samples from primary gastric carcinoma and lymph node metastasis tissue samples from 58 patients during gastric cancer resection were obtained using LMD in combination with cDNA microarray independently. After P27-based amplification, aRNA from 36 of 58 patients (group 1) with lymph node metastasis and metastatic tissue specimens from the remaining 22 patients (group 2) were applied to cDNA microarray. Semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemical assay verified the results of microarray in group 2 and further identified genes differentially expressed in the progression of gastric cancer.


RESULTS
The expression of 10 genes was up-regulated while the expression of 15 genes was down-regulated in 22 gastric carcinoma samples compared with that of genes in the normal controls. The results were confirmed at the level of mRNA and protein, and suggested that four genes (OPCML, RNASE1, YES1 and ACK1) could play a key role in the tumorigenesis and metastasis of gastric cancer. The expression pattern of 3 genes (OPCML, RNASE1 and YES1) was similar to tumor suppressor genes. For example, the expression level of these genes was the highest in normal gastric epithelium, which was decreased in primary carcinoma, and further decreased in metastatic lymph nodes. On the contrary, the expression pattern of gene ACK1 was similar to that of oncogene. Four genes were further identified as differentially expressed genes in the majority of the cases in the progression of gastric cancer.


CONCLUSIONS
LMD in combination with cDNA microarray provides a unique support foe the identification of early expression profiles of differential genes and the expression pattern of 3 genes (OPCML, RNASE1 and YES1) associated with the progression of gastric cancer. Further study is needed to reveal the molecular mechanism of lymph node metastasis in patients with gastric cancer.
Wang
Long
L
Department of Gastroenterology, Sixth People's Hospital Affiliated to Shanghai Jiaotong University, Shanghai 200233, China.
Zhu
Jin-Shui
JS
Song
Ming-Quan
MQ
Chen
Guo-Qiang
GQ
Chen
Jin-Lian
JL
D000368:Aged; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism; D004273:DNA, Neoplasm / Q000235:genetics; D018450:Disease Progression; D005260:Female; D058851:GPI-Linked Proteins; D020869:Gene Expression Profiling / Q000379:methods*; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D052138:Genes, Neoplasm / Q000235:genetics; D006801:Humans; D007834:Lasers; D008207:Lymphatic Metastasis / Q000235:genetics*; D008297:Male; D042282:Microdissection / Q000379:methods*; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D051575:Proto-Oncogene Proteins c-yes / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012259:Ribonuclease, Pancreatic / Q000235:genetics / Q000378:metabolism; D013274:Stomach Neoplasms / Q000235:genetics* / Q000378:metabolism; D015854:Up-Regulation / Q000235:genetics
D015815:Cell Adhesion Molecules; D004273:DNA, Neoplasm; D058851:GPI-Linked Proteins; C059785:OPCML protein, human; D011505:Protein-Tyrosine Kinases; D051575:Proto-Oncogene Proteins c-yes; C403262:TNK2 protein, human; C489834:YES1 protein, human; D012259:Ribonuclease, Pancreatic