Preferential transcription of a gene for alpha amylase in the carcinoid tumor of African rodent Mastomys natalensis.
The carcinoid tumor in Mastomys natalensis provides a useful animal model of tumorigenesis. We investigated preferentially transcribed genes in this carcinoid tumor by differential hybridization. Fourteen clones corresponding to high levels of transcription were isolated from a cDNA library. Sequencing analysis and a homology search revealed that the clones corresponded to genes for chromogranin and alpha-amylase. High-level transcription of a gene for alpha-amylase gene in Mastomys carcinoid tumor was confirmed by Northern blotting analysis. Furthermore, Western blotting analysis confirmed the expression of alpha-amylase in tumors at the protein level. Immunohistochemical staining revealed alpha-amylase in the cytoplasm of Mastomys carcinoid tumors. Our results demonstrated that an exocrine enzyme 'amylase' could be produced ectopically by a neuroen docrine tumor.
Daa
T
T
First Dept. of Pathology, Oita Medical University, Japan. daatom@oita-med.ac.jp
Sato
T
T
Kashima
K
K
Nakayama
I
I
Yokoyama
S
S
Takeno
S
S
Noguchi
T
T
Uchida
Y
Y
D000349:Africa; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002276:Carcinoid Tumor / Q000201:enzymology* / Q000473:pathology; D003001:Cloning, Molecular; D004273:DNA, Neoplasm / Q000378:metabolism; D020869:Gene Expression Profiling; D015723:Gene Library; D007124:Immunoenzyme Techniques; D008969:Molecular Sequence Data; D009115:Muridae / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D012334:RNA, Neoplasm / Q000378:metabolism; D012377:Rodentia; D012689:Sequence Homology, Nucleic Acid; D000516:alpha-Amylases / Q000235:genetics* / Q000302:isolation & purification
D004273:DNA, Neoplasm; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D000516:alpha-Amylases