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)

Human telomerase reverse transcriptase (hTERT) is the catalytic subunit and the key factor which controls the telomerase activity,so it is the best choice to inhibit telomerase through controling hTERT expression.In this work,a hammer head ribozyme directed against the hTERT mRNA (hTERTRZ) was designed and synthesized to serve as a telomerase inhibitor. In order to test its in vitro cleavage activity, two in vitro transcription plasmids containing hTERTRZ and hTERT gene respectively were constructed. Ribozyme RNA and DIG-labeled-hTERT were synthesized by in vitro transcription. In vitro cleavage reactions were carried out by mixing the hTERTRZ with DIG-labeled-hTERT under different reaction conditions, and cleavage bands were detected by digoxin chemiluminescent assay. hTERTRZ showed a specific cleavage activity against the hTERT used as template. To investigate its in vivo effect of telomerase inhibition in tumor cells, a eukaryotic expression plasmid containing the hTERT ribozyme gene was introduced into HeLa cells and hepatoma cells by using LipofectAMINE. In the transfectants, the level of intact hTERT mRNA and the telomerase activity were clearly reduced, and the telomere length of these clones was apparently shortened at the beginning period, then kept a fixed value without further shortening. All the transfectants with ribozyme grew clearly more slowly than the parental cell line. The doubling time of the tansfectants prolonged compared to the negative control, but no apparent apoptosis was shown even at their 37th passage. These findings suggest the potential application of this ribozyme as a new theraputic agent directed against immortalized cancer cells.
Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 2002 May
PMID:[Inhibition of telomerase activity by ribozyme targeted to human telomerase transcriptase]. 1201 45

Kunming mice inoculated with hepatoma cell (H22) suspension subcutaneously at their right axilla were administered orally with antioxidants such as vitamine E, beta-carotene, glutamine, kappa-selenocarrageenan and polysaccharide-peptide of coriolus (PSP) solution. It was found that the inoculated hepatoma growth was suppressed to various extents. The two kinds of polysaccharide antioxidants improved non-specific immunity, enhanced the nitrogen monoxide (NO) content in plasma and strengthened the inhibition of hepatoma. Above antioxidants added in the culture of 7721 human hepatoma cells inhibited the cell proliferation and inducedits apoptosis. Meanwhile, the activity of glutathione peroxidase (GSH-Px) in the plasma of mice increased and the content of malondialdehyde (MDA) decreased. H(2)O(2) in low concentration improved the cancer cell proliferation and inhanced the expression of Mn-SOD c-fos and c-jun, but led to cells apoptosis or necrosis in high concentration. The mechanism of antioxidants inhibiting tumor growth and improving cancer cells apoptosis might be that, on the one hand, the antioxidants blocked the free radicals signal transduction on cancer cells proliferation, and on the other hand, they improved the release of NO through enhancing the non-specific immunity, so inhibiting the cancer cells proliferation directly.
Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 2001
PMID:Inhibition of Proliferation and Expression of N-ras in Hepatoma Cells by Antioxidation Treatment. 1204 Apr 24

Human angiostatin cDNA was amplified from human hepatoma cell line HepG2 using RT-PCR and was cloned into pPIC9K vector. Recombinant Pichia pastoris strain with 4 copies of angiostatin gene was obtained. Recombinant protein was purified by lysine-affinity Sepharose column and the finally purified angiostatin was 25 mg/L, higher than previously reported 17 mg/L. Amino acid sequence analysis revealed the identity of our protein the same with that previously reported. Recombinant angiostatin inhibited specifically the proliferation of bovine aortic endothelial cell stimulated by bFGF, with ED(50) being about 3 mg/L.
Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 2001
PMID:Expression of Human Angiostatin in Pichia pastoris and the Detection of Its Anti-angiogenic Activity. 1205 Jul 88

Primary hepatocellular carcinoma(HCC) is one of the common malignant tumors in China. In our previous work, a gene named fup1(function-unknown protein 1) was isolated that was expressed differently in HCC and in normal liver. We assumed that it might be a candidate oncogene for the HCC. The fup1 gene had a ORF of 1 233 bp, encoding a protein with M(r) of 46 kD and isoelectric point of 5.48. The sequence characteristics showed its possible localization in nuclei. Northern blots showed that this gene was weakly expressed in many types of human tissues, except in the heart, implying its tissue-specific expression pattern. MTT assay of the NIH 3T3 cells transfected with this gene in the form of recombinant eukaryotic expression plasmid showed its enhancing role to cellular proliferation.
Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 2001
PMID:Cloning and Characterization of fup1, A Gene Highly Expressed in Hepatocellular Carcinoma. 1205 Aug 6

Three hammerhead ribozymes (RS3, RC2 and RC1) targeting to the HBV genome have been designed. Plasmids were constructed by inserting the genes of naked and tRNA-embedded ribozymes into RNA trimming vector pRG523 and then were transferred to eukaryotic expression vector. By the similar cloning method the shotgun-type plasmids carrying homogeneous RS3 or RtS3 unitconnected in tandem were obtained. After co-transfecting the above plasmids and HBV genome containing plasmid into human hepatoma cell line HepG2 respectively and selection by G418, the HBV-inhibiting activity of different kinds of ribozyme in G418-resistant cells was achieved by measuring the decrease of HBV-RNA, progeny DNA and the antigens expressed. The results showed that all the ribozymes were active with more than 70% inhibition activity against the HBV and that tRNA-embedded ribozymes had higher activity than naked ribozymes. It is worth particular interest that shotgun-type ribozymes with the connected unit in tandem with 8 and 12 units constructed in the plasmid revealed the highest activity, reaching >90% inhibition.
Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 2001
PMID:Hammerhead Ribozymes Suppress HBV(adr) in HepG2 Cells. 1205 84

NF-IL6 (Nuclear factor for IL-6 expression) is involved in inflammatory reaction, expression of acute-phase proteins and cytokines, apoptosis and suppression of tumor cells, and maintenance of macrophage immunological functions. To investigate the role of highly expressed exogenous NF-IL6 in macrophage tumor cytotoxicity, a recombinant expression plasmid, pCN, which harbored the coding region of NF-IL6, was transfected into murine primary cultured peritoneal resident macrophages by an improved DEAE-dextran method. Western blot showed the high expression of NF-IL6 in these macrophages. Then the tumor cytotoxicity of the NF-IL6-overexpressing macrophages from normal and nude mice was measured by an alkaline phosphatase assay, using the human hepatocarcinoma cell line SMMC 7721 as target cells. Results showed that the overexpression of NF-IL6 enhanced the tumor cytotoxicity in both types of macrophages, demonstrating that the expression level of the NF-IL6 gene was directly related to the tumoricidal activity in these cells.
Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 2001
PMID:Enhancement of Macrophage Cytotoxicity by Overexpression of Exogenous NF-IL6 Gene. 1205 86

To explore the role of FAK in TNF-alpha/cycloheximide-induced apoptos is of human hepatocellular carcinoma cell line SMMC-7721, the FAK antisense plasmid was constructed and transfected into SMMC-7721 cells. Western blot assay was adopted to examine PKB level. Flow cytometry assay was used to detect apoptosis. It was shown that the SMMC-7721 cells were insensitive to TNF-alpha cytotoxicity, but they entered apoptosis quickly in the presence of cycloheximide and TNF-alpha. PKB was decreased during TNF-alpha/cycloheximide-induced apoptosis. No significant change of PKB level was found in the presence of TNF-alpha or cycloheximide, respectively, seeming that PKB level was closely correlated with apoptosis. When FAK was 60% reduced as a result of the transfection of SMMC-7721 cells with FAK antisense construct, the percentage of TNF-alpha/cycloheximide-induced apoptosis was enhanced at lower dose of TNF-alpha but decreased at higher dose of TNF-alpha, compared with the control. Correspondingly, the PKB level in FAK-down-regulated transfectants was lower at lower dose of TNF-alpha, but higher at higher dose of it. Therefore, FAK regulated TNF-alpha/cycloheximide-induced apoptosis in a biphase manner. This function might be related with PKB level.
Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 2001
PMID:Role of FAK in TNF-alpha/Cycloheximide-induced Apoptosis of SMMC-7721 Cells. 1205 89

GST fusion protein expression system combined with protein truncation test(PTT) protocol was used to detect gene frame shift mutation. The RT-PCR products of Lis1 genes from hepatocarcinoma samples were respectively cloned into a GST fusion protein expression vector pGEX-1, then expressed in E.coli. The results showed a truncated 33 kD fusion protein in SDS-PAGE, although the full-translated product of Lis1 gene should be of 71 kD. Sequencing revealed insertion of an A residue, causing the premature termination of translation, between the 163th and 164th nucleotide of Lis1 gene. This improved PTT assay was proved to be a fast and effective way in detecting gene frame shift mutation.
Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 2000
PMID:Detection of Lis1 Gene Frame Shift Mutation in Human Hepatocarcinoma. 1207 32

The effects of some inhibitors of protein kinase C(PKC) and tyrosine protein kinase(TPK)as well as the antibodies to PKC isotypes on the activity of phosphatidylcholine-specific phospholipase D(PLD)in 7721 human hepatocarcinoma cells were determined in order to study the regulation of PKC and TPK on PLD in these cells. It was found that all of the four inhibitors of PKC (chelerythrine, H-7, calphostin C and stausporine) and two inhibitors of TPK (tyrphostin 46 and genistein) partially inhibited the basal activity of PLD. Among them, the inhibition rates of staurosporine and calphostin C were the highest. The effects of TPK inhibitors were less than that of PKC inhibitors. When the inhibitors of PKC and TPK were added in combination, the inhibitory effect was greater than that used separately. A well known physiological inhibitor of PKC, D-sphingosine, did not show any inhibition, but did show stimulation on PLD activity. The mechanism is probably related to the transformation of D-sphingosine to D-sphingosine 1-phosphate, a stimulator of PLD via the activation TPK (and probably also PKC). The stimulating effects of both D-sphingosine and D-sphingosine 1-phosphate were blocked by TPK inhibitors and other PKC inhibitors. Among the 3 common PKC isotypes in human hepatocarcinoma cells, PKCalpha and PKCbetaI may be the main isotypes of PKC in the regulation of PLD.
Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 1999
PMID:Regulation of Phospholipase D Activity in Human Hepatocacinoma Cells by Protein Kinases and D-sphingosine. 1211 73

The effects of the epidermal growth factor (EGF), a stimulator of tyrosine protein kinase (TPK), and phorblol-12-myristate-13-acetate (PMA), a stimulator of protein kinase C (PKC), on the activity of N-acetylglucosaminyltransferase V (GnT-V) were studied in human hepatocarcinoma cell line 7721 in order to elucidate the regulation of TPK and PKC on GnT-V. It was found that the GnT-V activity obviously increased after treatment of the cells with EGF or PMA for 48 h. A non-specific protein kinase inhibitor, quercetin, inhibited the activities of TPK and PKC(inhibited mainly the membranous TPK and PKC)as well as GnT-V simulatanously. Moreover, quercetin completely eliminated the stimulating effect of EGF or PMA on GnT-V. When Tyrohostin-25, a specific inhibitor of TPK, or sphingosine, the specific inhibitor of PKC, was used separately to substitute for quercetin, the induction effect of EGF of PMA on GnT-V was only partially eliminated. However, when both Tyrphostin-25 and sphingosine were added to the culture medium, the elevation of GnT-V caused by EGF or PMA was entirely blocked. Cycloheximide, a well-known inhibitor of protein synthesis, showed an effect similar to the inhibition of protein kinases;it not only inhibited the basal activity of GnT-V, but also abolished the inducing stimulation of GnT-V by EGF of PMA. These results indicate that EGF or PMA regulates the activity of GnT-V via protein kinases, and GnT-V is regulated by dual mechanism of membranous TPK and PKC. Membranous TPK is more important that membranous PKC in the regulation of GnT-V.
Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 1998
PMID:Dual Regulation of Tyrosine Protein Kinase and Protein Kinase C on N-acetylglucosaminyltransferase V. 1216 8


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