Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0019204 (hepatocellular carcinoma)
 71,386 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Telomerase is an important tumor marker but few antibodies to the enzyme have been described or used without difficulty in histochemical detection. Here we report specific detection of the enzyme in cell and tissue preparations using a new monoclonal antibody (mAb 476) and a new antigen-retrieval buffer (Enhancing buffer). When used to detect telomerase under normal immunostaining conditions in HL-60 cells or tissue sections of hepatocellular carcinoma or metastatic choriocarcinoma, unexpectedly, the antibody stained the cytoplasm rather than the nucleus. Nuclear staining, however, was revealed using the Enhancing buffer. Since other nuclear antigens in the HL-60 cell could be stained both ordinarily and in the Enhancing buffer, nuclear telomerase appears to be shrouded by the nuclear matrix or blocked by accessory proteins. The cytoplasmic activity seen in normal buffer but absent largely from the Enhancing buffer may be an artifact or the nascent, "naked" enzyme. With a known cytoplasmic antigen (proteinase-3) chosen arbitrarily for comparison, the antigenicity was found enhanced, instead, by the Enhancing buffer. The mode of action of the Enhancing buffer differs from that of microwave irradiation or the signal amplification (CSA) used by some investigators. The latter was found to enhance the cytoplasmic reactivity rather than the nuclear reactivity of mAb 476.
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PMID:Nuclear telomerase is less accessible to antibody probing than known nuclear antigens: retrieval with new immunostaining buffer. 1553 12

The biosynthetic nanoscale peptide Cecropin A is postulated to disrupt microbial phospholipid membranes by forming stable or transient pores. We demonstrated previously that green fluorescent protein (GFP), driven by the survivin promoter, was expressed highly in HepG2 but not in LO2 cells when they were transfected with the recombinant plasmid reporter vector (pSURV-GFP). To investigate the selective killing effect of this survivin promoter-driven peptide toxin gene system on hepatocellular carcinoma (HCC) cells in vitro, the recombinant plasmid pSURV-Cecropin A was constructed. HepG2 and LO2 cells were then transfected with the recombinant plasmid, which was driven by the survivin promoter, and the effects of Cecropin A were evaluated. Forty-eight hours after transfection with pSURV-Cecropin A, the growth of HepG2 cells was inhibited significantly. This finding was confirmed further by immunoblotting, which revealed consistently suppressed expression of proliferating cell nuclear antigen (PCNA) and cysteinyl aspartate specific proteinase-3 (caspase-3). Data demonstrated that the plasmid carrying the gene for the Cecropin A fusion protein was constructed successfully, and that its specific expression in HepG2 cells could provide the basis for targeted gene therapy in HCC. The identification of novel gene therapies for cancer is highly desirable to reduce drug toxicity and improve therapeutic outcomes..
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PMID:Gene therapy with biosynthetic nanoscale peptide Cecropin A driven by the survivin promoter for hepatocarcinoma cells. 2480 59