[Cloning and primary expression analyses of down-regulated cDNA fragment in human gastric cancer].
OBJECTIVE
To identify human gastric cancer related genes.


METHODS
Specimens of paired tumor, paratumor and normal gastric mucosa tissues were collected from five patients (male 3, female 2, with average age 48.8 +/- 18.1 years) who suffered from stomach antrum adenocarcinoma. Total RNA samples were extracted from these specimens, then studied by fluorescent differential display reverse transcription polymerase chain reaction (DDRT- PCR) analysis. The differentially expressed bands of interest were recovered, purified and cloned, then they were analyzed by sequencing, Northern blot and RT-PCR. Through BLAST, the sequencing results were compared with GenBank database for homology analysis.


RESULTS
One of the interesting cDNA bands expressed much lower in all five tested tumor samples than in their normal and paratumor counterparts. This band was named W4. Northern blot analysis showed a consistent result with that of DDRT-PCR. W4 was cloned into pGEM-T easy vector. Sequence analysis showed that W4 consists of 712bp, this sequence was named W44. BLAST analysis revealed that W44 has extremely low sequence identity with any genes from GenBank and any sequences from EST database. This sequence data was submitted to GenBank with accession No. AF150631. RT-PCR analysis showed that W4 was expressed much lower in 11/15 gastric cancer tissue than in paratumor and normal samples.


CONCLUSIONS
A novel cDNA sequence related to human stomach adenocarcinoma was identified.
Wang
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Department of Gastroenterology, General Hospital of Chinese PLA, Beijing, 100853 P.R. China. wanggangshi@hotmail.com
Wang
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You
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Li
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D000328:Adult; D000368:Aged; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000032:analysis*; D015536:Down-Regulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000235:genetics*
D018076:DNA, Complementary