[Identification of a new molecular marker related to tumorigenesis of the stomach and small intestine].
OBJECTIVE
Screening and identification of molecular markers associated with tumorigenesis of the gastrointestinal tract.


METHODS
Techniques of random amplified polymorphic DNA (RAPD), restriction fragment length polymorphism (RFLP), Southern blot and Northern blot, gene cloning and sequencing were employed to reveal new molecular markers from tumors of different origins.


RESULTS
Of 32 RAPD fragments possibly associated with tumorigenesis, 29 were cloned into pCAPs vector. Further analysis by Southern blot revealed that the majority of the cloned fragments was repetitive sequences. Among the remaining single-copy fragments, one was found deleted in malignant tumors of the stomach and small intestine. It did not hybridize with mRNA extracted from blood lymphocyte and cultured fibroblasts. Sequence analysis indicated that this single-copy fragment contained a motif similar to eukaryotic cis-acting "CACA" box promoter. At its downstream there was an "ATG" transcription activator codon. No homologous sequence was found in the GenBank and it was therefore accepted by the GenBank. (Accession Number: AF151005).


CONCLUSIONS
A single-copy fragment containing cis-acting "CACA" box has been identified, which might be the upstream of a new tumor suppressor gene deleted in tumors of the stomach and small intestine.
Wang
J
J
Central Laboratory, First Affiliated Hospital of Guangdong Medical College, Zhanjiang 524001, China.
Ye
F
F
D014408:Biomarkers, Tumor / Q000032:analysis; D016147:Genes, Tumor Suppressor / Q000502:physiology; D006801:Humans; D007414:Intestinal Neoplasms / Q000209:etiology / Q000235:genetics*; D009154:Mutation; D012150:Polymorphism, Restriction Fragment Length; D011401:Promoter Regions, Genetic; D013274:Stomach Neoplasms / Q000209:etiology / Q000235:genetics*
D014408:Biomarkers, Tumor