Lysosomal alpha-mannosidase (EC 3.2.1.24) is an exoglycosidase in the glycoprotein degradation pathway and is encoded by a 3.0 kb cDNA. A 2.3 kb cDNA from a minor species of HeLa cell mRNA was discovered by RT-PCR cloning. Southern blotting and PCR analysis of the HeLa cell genomic DNA showed that the 2.3 kb message was encoded by the lysosomal alpha-mannosidase gene. Sequence comparison of the cDNA with the corresponding genomic DNA indicated that the 2.3 kb message was generated by an unusual intra-exonic joining event.
*Alternative Splicing ; Base Sequence ; DNA, Complementary/genetics ; Exons ; Hela Cells ; Human ; Lysosomes/*enzymology ; Mannosidases/*genetics ; Molecular Sequence Data ; RNA, Messenger/*genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Support, U.S. Gov't, P.H.S.

Lysosomal alpha-mannosidase (EC 3.2.1.24) is a major exoglycosidase in the glycoprotein degradation pathway. A deficiency of this enzyme causes the lysosomal storage disease, alpha-mannosidosis, which has been described in humans, cattle, domestic cats and guinea pigs. Recently, great progress has been made in studying the enzyme and its deficiency. This includes cloning of the gene encoding the enzyme, characterization of mutations related to the disease, establishment of valuable animal models, and encouraging results from bone marrow transplantation experiments.
Animal ; Cats ; Cattle ; Cloning, Molecular ; Disease Models, Animal ; Guinea Pigs ; Human ; Lysosomes/*enzymology ; Mannosidases/*deficiency/*genetics/metabolism ; Mannosidosis/diagnosis/*etiology/*therapy ; Mutation ; Support, Non-U.S. Gov't ; Support, U.S. Gov't, P.H.S. ; Transcription, Genetic

OBJECTIVETo study the effect of human alpha-mannosidase Man2c1 transgene on tumor growth and metastasis in mice.

METHODSHepatoma cell H22 or squamous epithelial carcinoma cell S180 was subcutaneously inoculated into the right armpit of mice (wild type mice and 28#, 35#, and 54# transgenic mice). Tumor size was measured every week. Mice were sacrificed on day 9 or 10 and then the tumors were exercised and weighted. Tumors and lungs were fixed in formaldehyde and sectioned. The sections were stained with hematoxylin/eosin and examined under microscope. The red blood cells in spleen were destroyed by Tris-NH4Cl. Natural killer (NK) cell activity was detected with Yac-1 cell as target.

RESULTSH22 and S180 tumors grew faster in all the three transgenic mice (28#, 35#, and 54#) than in wild type mice. The average size and weight of tumors between the transgenic mice and wild type mice were significantly different (P<0.05). Most tumors in the transgenic mice invaded the surrounding tissues. In contrast, nearly all the tumors in wild type mice were capsulized. Three of 10 28# transgenic mice, 5 of 10 35# transgenic mice, 3 of 10 54# transgenic mice, and 1 of 10 wild type mice showed lung metastasis of H22 tumor. Two of 6 28# transgenic mice, 3 of 6 35# transgenic mice, 1 of 6 54# transgenic mice, and 0 of 6 wild type mice showed lung metastasis of S180 tumor. No difference of NK activity in spleen cells was observed between the transgenic mice and wild type mice.

CONCLUSIONShMan2c1 transgene promotes growth, invasion, and metastasis of transplanted H22 and S180 tumors in mice. hMan2cl transgene does not affect NK activity in splenocytes.

Animals ; Cell Line, Tumor ; Humans ; Killer Cells, Natural ; immunology ; Lung Neoplasms ; secondary ; Mannosidases ; genetics ; Mice ; Mice, Transgenic ; Neoplasm Invasiveness ; Neoplasm Transplantation ; Neoplasms, Experimental ; immunology ; metabolism ; pathology ; Spleen ; immunology ; Transgenes

OBJECTIVETo define the differences in gene expression patterns between glycidyl methacrylate (GMA)-transformed human lung fibroblast cells (2BS cells) and controls.

METHODSThe mRNA differential display polymerase chain reaction (DD-PCR) technique was used. cDNAs were synthesized by reverse transcription and amplified by PCR using 30 primer combinations. After being screened by dot blot analysis, differentially expressed cDNAs were cloned, sequenced and confirmed by Northern blot analysis.

RESULTSEighteen differentially expressed cDNAs were cloned and sequenced, of which 17 were highly homologous to known genes (homology = 89%-100%) and one was an unknown gene. Northern blot analysis confirmed that eight genes encoding human zinc finger protein 217 (ZNF217), mixed-lineage kinase 3 (MLK-3), ribosomal protein (RP) L15, RPL41, RPS 16, TBX3, stanniocalcin 2 (STC2) and mouse ubiquitin conjugating enzyme (UBC), respectively, were up-regulated, and three genes including human transforming growth factor beta inducible gene (Betaig-h3), alpha-1,2-mannosidase 1A2 (MAN 1A2) gene and an unknown gene were down-regulated in the GMA-transformed cells.

CONCLUSIONAnalysis of the potential function of these genes suggest that they may be possibly linked to a variety of cellular processes such as transcription, signal transduction, protein synthesis and growth, and that their differential expression could contribute to the GMA-induced neoplastic transformation.

Air Pollutants, Occupational ; toxicity ; Carcinoma, Squamous Cell ; genetics ; pathology ; Cell Line, Transformed ; Epoxy Compounds ; toxicity ; Fibroblasts ; cytology ; drug effects ; Gene Expression Profiling ; Glycoproteins ; metabolism ; Humans ; Lung ; cytology ; Male ; Mannosidases ; drug effects ; metabolism ; Methacrylates ; toxicity ; Mitogen-Activated Protein Kinase 3 ; drug effects ; metabolism ; Oligonucleotide Array Sequence Analysis ; Ribosomal Proteins ; metabolism ; Signal Transduction ; genetics ; Transforming Growth Factor beta ; drug effects ; metabolism ; Ubiquitins ; metabolism ; Zinc Fingers ; drug effects ; physiology