Identification and cloning of a novel isoform of mouse secretory leukocyte protease inhibitor, mSLPI-beta, overexpressed in murine leukemias and a highly liver metastatic tumor, IMC-HA1 cells.
Several genes showing transcriptional alteration in a highly liver metastatic murine carcinoma cell line, IMC-HA1, were identified by mRNA differential display system. Among them, a gene identical to mSLPI was isolated as mSLPI-alpha and -beta. They were produced through an alternative splicing. Their full-length cDNA sequences were determined, and their expression in various murine tumors and normal tissues was analysed. The deduced translation product of mSLPI-alpha showed 59% identity to hSLPI. Although mSLPI-beta had the same 103-amino-acid sequence from the carboxyl terminus, the amino terminus showed hydrophilicity opposite mSLPI-alpha or hSLPI. The mSLPI-alpha was expressed ubiquitously in various tumor cell lines. Interestingly, however, mSLPI-beta expression was only observed in P388 and L1210 leukemias and IMC-HA1 cells, and in lower amounts in three normal tissues (thymus, lung and spleen), suggesting that mSLPI, and in particular the unusual splicing product, mSLPI-beta, plays a specific role in these cells, including malignant processes of tumor cells.
Morita
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M
Banyu Tsukuba Research Institute, Merck Research Laboratories, Ibaraki, Japan.
Arakawa
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H
Nishimura
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S
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D005260:Female; D015870:Gene Expression; D007942:Leukemia, Experimental / Q000235:genetics*; D008114:Liver Neoplasms, Experimental / Q000235:genetics / Q000556:secondary; D051379:Mice; D008807:Mice, Inbred BALB C; D008811:Mice, Inbred DBA; D008969:Molecular Sequence Data; D009374:Neoplasms, Experimental / Q000235:genetics* / Q000556:secondary; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics; D053491:Proteinase Inhibitory Proteins, Secretory; D011506:Proteins / Q000737:chemistry / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012334:RNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D015842:Serine Proteinase Inhibitors / Q000737:chemistry / Q000235:genetics*; D014018:Tissue Distribution; D014407:Tumor Cells, Cultured
D017931:DNA Primers; D018076:DNA, Complementary; D020033:Protein Isoforms; D053491:Proteinase Inhibitory Proteins, Secretory; D011506:Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D015842:Serine Proteinase Inhibitors