Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P10415 (Bcl-2)
 33,771 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have isolated two stable human bcl-2 transfected cell lines, HCC-T-bcl and PLC-bcl, that were derived from the transfection of two human hepatocellular carcinoma cell lines (HCC-T and PLC/PRF/5, respectively) with a plasmid vector containing recombinant bcl-2 (pCAGGS-bcl).) Cell lines transfected with the plasmid alone (pCAGGS-neo) were also established as controls (HCC-T-neo and PLC-neo). HCC-T-neo and PLC-neo were sensitive to doxorubicin-induced apoptosis, as defined by morphological observation. Although HCC-T-neo expressed endogenous Bcl-2, the sensitivity of HCC-T-neo to doxorubicin-induced cytotoxicity was similar to that of PLC-neo, which does not express endogenous Bcl-2. In contrast, both HCC-T-bcl and PLC-bcl were more resistant to doxorubicin-induced cytotoxicity. Although these bcl-2 transfectants were resistant to the drug-induced apoptosis, Bcl-2 overexpression did not affect doxorubicin-induced growth suppression. These results suggest that the overexpression of Bcl-2 renders human HCC cells resistant to doxorubicin-induced cytotoxicity.
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PMID:Bcl-2 prevents doxorubicin-induced apoptosis of human liver cancer cells. 1264 56

3-Bromopropionylamino benzoylurea (JIMB01) is a small molecular weight compound (MW 313) that has been synthesized in our laboratory. This compound showed antiproliferative activities in a panel of thirteen human tumor cell lines with IC(50) values in the range of 0.25 to 0.51 micro M for leukemia and lymphoma cell lines and 0.33 to 9.26 micro M for solid tumor cell lines. The primary action of JIMB01 is to inhibit microtubule polymerization but not depolymerization. A 4 micro M concentration of the compound caused a complete inhibition of microtubule assembly in a cell-free reaction. An increase in the number of human hepatocarcinoma cells blocked in the M-phase was detected 12hr after exposure to JIMB01. The kinase activity of cyclin B1, which is responsible for the G(2)/M transition, was increased accordingly. Bcl-2 phosphorylation became visible, in a western blot, within 6hr in hepatocarcinoma cells treated with JIMB01 at 0.8 micro M or higher. JIMB01-induced apoptosis in liver cancer cells was confirmed by morphological methods, flow cytometry, as well as DNA gel electrophoresis, which clearly demonstrated DNA degradation in the form of a multiple-unit DNA ladder. Furthermore, in vivo experiments using nude mice showed that intraperitoneal injection of JIMB01 at 15mg/kg (with seven injections at 4-day intervals) significantly inhibited the growth of a human hepatocarcinoma (BEL-7402) by 66% in tumor volume (P=0.01), at least compatible to the inhibition by vincristine (43% inhibition), indicating good bioavailability of the compound in the circulation. Side-effects of the compound were not observed, and the body weight of the treated mice remained stable during the 4-week treatment. Since JIMB01 is a small compound, targets a specific molecule in tumor cells, and has promising activity against human hepatocarcinoma in vivo, we believe JIMB01 merits consideration for further investigation.
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PMID:Inhibition of microtubule polymerization by 3-bromopropionylamino benzoylurea (JIMB01), a new cancericidal tubulin ligand. 1275 5

Exposure to agonists of peroxisome proliferator-activated receptor alpha (PPARalpha) causes liver cancer in rodents, with aged animals being more susceptible than their younger counterparts to this effect. Treatment with these chemicals produced a five- to sevenfold higher yield of grossly visible hepatic tumors in old rats compared to young animals. The enhanced susceptibility of the aged livers to the carcinogenic effect of PPAR agonists could not be explained by differences in levels of peroxisomal and/or cell proliferation between young and old animals, as neither of these responses was exaggerated with aging. Reported studies have shown that activating PPARalpha results in the suppression of hepatic apoptosis. This effect is expected to diminish the ability of the liver to purge itself of pre-existing neoplastic cells, allowing them to progress to tumors. New findings from our laboratories show that the aged liver is exceedingly sensitive to the antiapoptotic effect of PPAR agonists. In addition, aged livers showed remarkably higher levels of the antiapoptotic protein Bcl-2 than livers of young, adult, and middle-aged animals. Interestingly, the PPARalpha agonist Wy-14,643 significantly diminished elements of the proapoptotic machinery (e.g., Bax, caspases, and fas) in the aged liver, while remarkably increasing elements of this machinery in younger animals. Taken together, while activation of PPARs appears to inhibit apoptosis in livers of senescent animals, activating these receptors seems to stimulate the apoptotic machinery in young animals. This paradoxical effect may be responsible for the exaggerated sensitivity of the aged liver to the carcinogenic effect of agents that activate PPARs.
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PMID:Enhanced hepatocarcinogenicity due to agonists of peroxisome proliferator-activated receptors in senescent rats: role of peroxisome proliferation, cell proliferation, and apoptosis. 1280 35

The present study was to investigate the chemopreventive effects of tea pigments. In vitro study showed that tea pigments induced QR activity and GST activity in Hep G2 cells. Three animal models were used to observe the preventive effects of tea pigments on liver cancer, colorectal cancer and oral cancer. Oral administration of 0.1% tea pigments increased GST activity in rat liver by 18%, and this increase was accompanied by the significant increase of GST 1-1, 1-2, and 3-3 protein expression in rat liver. Tea pigments inhibited the proliferating cell nuclear antigen labeling index (PCNA-LI), the expression of Bcl-2 protein and ras-p21 protein, and induced the expression of Bax protein in rat colorectal cancer. PCNA-LI, silver-stained nucleolar organizer regions (AgNOR) and epidermal growth factor receptor (EGFR) expression were also inhibited by tea pigments in hamster oral cancer. Our results suggested that tea pigments had chemopreventive effects on cancer, and the anti-cancer properties may be due to the activation of detoxifying enzymes such as QR and GST, the inhibition of cell proliferation and the induction of apoptosis.
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PMID:[Studies on cancer chemoprevention by tea pigments]. 1496 10

Sodium butyrate is a short-chain fatty acid produced by fermentation in the gastrointestinal tract. It induces differentiation of several kinds of cancer by inhibiting histone deacetylase activity. We have reported that butyrate stimulates hepatocellular carcinoma cells into their normal phenotype. Since sodium butyrate affects both differentiation and apoptosis, we investigated expression of bcl-2-related genes in a human hepatocellular carcinoma cell line HCC-T. The expression of anti-apoptotic Bcl-2 and Mcl-1/EAT was up-regulated 4 h after the treatment, while pro-apoptotic Bax expression did not change. Gene expressions in the early stage of butyrate-stimulation were investigated by the differential display assay and the cDNA expression array. Laminin and keratin 18 were increased 6 h after the stimulation with sodium butyrate. The results of cDNA expression array revealed up-regulation of cell cycle inhibitory genes such as cyclin-dependent kinase 4 inhibitor, and interferon-related genes such as STAT2 and 3, while down-regulation of cyclin-dependent kinase 2 and cyclin E. Up-regulated production of p21WAF-1 and Mcl-1/EAT was also confirmed by Western blotting. The cytoskeletal change indicated by up-regulation of laminin and keratin 18 may be an important factor in the decrease in malignant phenotype of cancer cells. Up-regulation of interferon-related genes indicated that butyrate-treatment might induce a similar phenotypic change to that induced by type 1 interferons. This study suggests several target genes for the future gene therapy of cancer or genes preventing cancer development from pre-malignant tissues.
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PMID:Gene expression associated with the decrease in malignant phenotype of human liver cancer cells following stimulation with a histone deacetylase inhibitor. 1558 45

The fruiting body of Antrodia camphorata is well known in Taiwan as a traditional medicine for treating cancer and inflammation. The purpose of this study was to evaluate the apoptotic effects of ethylacetate extract from A. camphorata (EAC) fruiting bodies in two human liver cancer cell lines, Hep G2 and PLC/PRF/5. Treatment with EAC decreased the cell growth of Hep G2 and PLC/PRF/5 cells in a dose dependent manner. In Fas/APO-1 positive-Hep G2 cells, EAC increased the expression level of Fas/APO-1 and its two forms of ligands, membrane-bound Fas ligand (mFasL) and soluble Fas ligand (sFasL), in a p53-indenpendent manner. In addition, EAC also initiated mitochondrial apoptotic pathway through regulation of Bcl-2 family proteins expression, release of cytochrome c, and activation of caspase-9 both in Hep G2 and PLC/PRF/5 cells. Furthermore, EAC also inhibited the cell survival signaling by enhancing the amount of IkappaBalpha in cytoplasm and reducing the level and activity of NF-kappaB in the nucleus, and subsequently attenuated the expression of Bcl-X(L) in Hep G2 and PLC/PRF/5 cells. EAC therefore decreased the cell growth and induced apoptosis both in Hep G2 and PLC/PRF/5 cells.
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PMID:Apoptotic effects of extract from Antrodia camphorata fruiting bodies in human hepatocellular carcinoma cell lines. 1579 30

Interferon (IFN)-alpha directly inhibits proliferation of liver cancer cells by inducing apoptosis, but the molecular mechanisms by which IFN-alpha induces apoptosis in these cells are not fully understood. We examined the effect of broad spectrum caspase inhibitor, Z-VAD-fmk, and the caspase activation in IFN-alpha-mediated apoptosis by using 4 liver cancer cell lines that were sensitive or resistant to IFN-alpha-mediated apoptosis. Involvement of apoptosis-related mitochondrial proteins and Bcl-2 family proteins in IFN-alpha-mediated apoptosis was further examined in 1 sensitive cell line (KIM-1). The Z-VAD-fmk completely or moderately inhibited IFN-alpha-mediated apoptosis in the sensitive cells. IFN-alpha induced time-dependent activation of caspase-3 in the sensitive cells, while the resistant cells showed mild or no activation. Activation of caspase-9, caspase-8, and caspase-7, and the cleavage of poly(ADP-ribose)polymerase were identified in either or both of the sensitive cell lines, but not in the resistant cells. In KIM-1 cells, the release of cytochrome c and Smac/DIABLO from mitochondria to cytosole was confirmed. Meanwhile, Bcl-xL was upregulated, and Bid activation or translocation, or conformational changes of Bax were not identified. In conclusion, our results suggest IFN-alpha-mediated apoptosis in liver cancer cells involves the mitochondrial apoptotic pathway and is induced by activating various caspases.
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PMID:Expression and activation of apoptosis-related molecules involved in interferon-alpha-mediated apoptosis in human liver cancer cells. 1587 Aug 81

Chemosensitivity is affected by molecular biological factors, including factors related to the induction of apoptosis and the activity of proliferation. We analyzed immunohistochemically the expression of p53, Bcl-2, and Ki-67 in various types of cancers and assessed the correlation between this expression and chemosensitivity. Moreover, we investigated whether the expression of these factors could be a useful predictor for the clinical response to chemotherapy. Study subjects comprised 63 preoperative patients with untreated malignant tumors (9 with esophageal cancer, 12 with stomach cancer, 12 with colon cancer, 16 with liver cancer, and 14 with breast cancer). Immunohistochemical staining (the labeled streptavidin biotin technique: LSAB method) was used to assess expression of p53 protein, Bcl-2 protein, and Ki-67. A chemosensitivity test was carried out with the histoculture drug response assay method using four drugs: mitomycin C, 5-fluorouracil, doxorubicin hydrochloride (ADM), and cisplatin (CDDP). Immunohistochemical studies for p53 were found to be useful for predicting chemosensitivity.
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PMID:Immunohistochemistry of p53, Bcl-2, and Ki-67 as predictors of chemosensitivity. 1590 38

The hepatic cancer HA22T/VGH cell line, which constitutively expresses activated nuclear factor-kappaB (NF-kB), was chosen as a model to examine the antitumor activity of curcumin, also in relationship to its possible influences on the activation of the transcription factor and on the expression of the inhibitory of apoptosis proteins (IAPs) and of other NF-kB target genes. Curcumin exerted cell growth inhibitory and apoptotic effects, related, at least part, to free radical generation and mainly dependent on caspase-9 and -3 activation. The combination of curcumin with cisplatin resulted in a synergistic antitumor activity and that with doxorubicin in additivity or sub-additivity. Curcumin exerted biphasic changes in the levels of NF-kB, with an increase at 8 h after its administration and a decrease at 16 h. For the combinations of curcumin with the other drugs, the levels of the transcription factor were lower than those predicted from the effects of the single agents, especially with a blunting of the remarkable increases in NF-kB activation induced by doxorubicin. Except for Bcl-2, the HA22T/VGH cells expressed different other genes, including the IAPs, implicated in cell proliferation and survival. Curcumin determined early changes in COX-2 and c-myc mRNAs, which were down-regulated, and in livin mRNA, which was up-regulated. Later it decreased Bcl-X(L) mRNA and increased Bcl-X(S) and c-IAP-2 mRNAs. Cisplatin and doxorubicin exerted distinct effects on gene expression. The cytotoxic interactions between curcumin and these agents were accompanied by synergistic (in particular with cisplatin) or additive effects of decrease in the expression of different genes, including c-myc, Bcl-X(L), c-IAP-2, NAIP and XIAP. However, the combinations attenuated also certain other influences on mRNA expression of the single agents, like, for example, the increases in Bcl-X(s) given by curcumin and doxorubicin. Overall, the effects of the drugs, alone or in combination, on tumor cell growth, cell death and gene expression did not show a simple relationship to the relative influences on NF-kB activation, inferring that they can be due also to other mechanisms.
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PMID:Antitumor effects of curcumin, alone or in combination with cisplatin or doxorubicin, on human hepatic cancer cells. Analysis of their possible relationship to changes in NF-kB activation levels and in IAP gene expression. 1591 Nov 1

Glycyrrhetinic acid (GA) and its related compounds are known to have anti-inflammatory activity and also to inhibit liver carcinogenesis and tumor growth. GA and related compounds inhibited cell proliferation of the human hepatoma cell line, HepG2. Among five compounds tested, ursolic acid and 18beta-olean-12-ene-3beta, 23, 28-triol (18beta-erythrotriol) were comparatively effective, where the 50% inhibitory dose was 20 microM and 25 microM, respectively. Flow-cytometric analysis showed that GA and the related compounds arrested the cell cycle in the G1-phase; in addition, GA-related compounds induced apoptosis at high dose. Western blot analysis indicated that the induction of apoptosis by GA and ursolic acid was accompanied with an activation of caspase-8 and a reduction in the anti-apoptotic proteins, Bcl-2 and Bcl-xL, although the pro-apoptotic proteins, Bax and Bak, remained unaffected. These results suggest that GA and its related compounds may be potent agents in liver cancer treatment.
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PMID:Glycyrrhetinic acid and related compounds induce G1 arrest and apoptosis in human hepatocellular carcinoma HepG2. 1630 97


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