Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C1864663 (HCC)
 2,985 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Truncated transcripts terminating within the HBx frame have been recognized previously in tumor and liver tissue of HCC patients. In this study biological activities of a predicted truncated HBx fused to a polylysin stretch (HBtx-polylysin) and of full length HBx were compared in NIH3T3 cells transfected with respective cDNA plasmids. Transactivation of a co-transfecting reporter gene and influence on neor DNA mediated transformation to G418 resistance were determined. In comparison to full length HBx the data indicate for HBtx-polylysin a lower transactivating capacity and as judged by the yield of colonies on a solid surface, a lower capacity to stimulate neor DNA mediated transformation. In soft agar the outgrowth into G418 resistant colonies was dependent on co-transfecting HBx cDNA. In providing this condition HBtx-polylysin had a much higher relative activity than full length HBx. Large cointegrants consisting of the plasmids carrying truncated HBx cDNA and neor DNA respectively were identified by chromosomal in situ hybridization. Based on Southern blot analyses extended concatemeres of the HBx cDNA plasmid constituted a main part of the cointegrants. Expression of truncated HBx cDNA was followed on the RNA and the protein level. The presence of this cDNA could be correlated to a compact spindle like cell appearance, its loss after prolonged passaging in the absence of G418 to a concomitant reversion to the phenotype of the NIH3T3 cell. Interspersed selection for G418 resistance stabilized the morphologically transformed phenotype. These results provide a basis to manipulate expression of truncated HBx and to recognize thereby processes leading to transformation.
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PMID:Biological activities of a putative truncated hepatitis B virus X gene product fused to a polylysin stretch. 805 25

A ribozyme (RZ) gene targeting c-myc mRNA was synthesized and cloned. Cleavage reaction showed that cleavage of the RZ was efficient and specific. The RZ gene-containing retrovirus vector pDOR-RZ was transfected into HCC-9204 hepatoma cells, which constitutively express high levels of c-myc using Lipofectamine. Positively transfected cells were selected using G418. In situ hybridization showed that both pDOR-RZ and pDOR vectors had been integrated into the chromosome of HCC-9204 cells. Dot blot hybridization indicated that expression of the RZ was only evident in pDOR-RZ-transfected HCC-9204 cells. Avidin-biotin complex enzyme-linked immunosorbent assay showed that c-myc expression was down-regulated. Chromatin aggregation into compact masses, cytoplasmic vacuole degeneration, and blurring of cytoplasm structure were observed by transmission electron microscopy in HCC-9204-RZ cells. These results suggest that the use of a c-myc mRNA cleaving enzyme could be most effective in tumor cells that are highly proliferative and constitutively express high levels of c-myc.
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PMID:Inhibition of cell proliferation in HCC-9204 hepatoma cells by a c-myc specific ribozyme. 1076 46