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)

Integrin-basement membrane interactions provide essential signals that promote survival and growth of epithelial cells, whereas loss of such adhesions triggers programmed cell death. We found that HSC-3 human squamous carcinoma cells survived and grew readily as monolayers, but when they were suspended as single cells, they ceased proliferating and entered into the apoptotic death pathway, characterized by DNA fragmentation. In contrast, if the suspended carcinoma cells were permitted to form E-cadherin-mediated multicellular aggregates, they not only survived but proliferated. However, aggregated normal keratinocytes were unable to survive in suspension culture and rapidly became apoptotic. Anchorage independence and resistance to apoptosis of HSC-3 cell aggregates required high levels of extracellular Ca2+ and was inhibited with function-perturbing anti-E-cadherin antibody. Resistance to suspension-induced apoptosis in cell aggregates paralleled the up-regulation of Bcl-2 but occurred in the absence of focal adhesion kinase activation. Analysis of suspension-induced death in a set of cloned squamous epithelial cell lines with different levels of E-cadherin expression revealed that receptor-positive cell clones evaded apoptosis and proliferated in three-dimensional aggregate culture, whereas cadherin-negative clones failed to survive. Collectively, these observations indicate that cadherin-mediated intercellular adhesions generate a compensatory mechanism that promotes anchorage-independent growth and suppresses apoptosis.
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PMID:E-cadherin regulates anchorage-independent growth and survival in oral squamous cell carcinoma cells. 964 58

While enhanced expression of cyclooxygenase (COX)-2 has been observed in human skin epidermal cancer, the mechanisms underlying COX-2 expression have not been completely elucidated. Recently, a role for the phosphatidylinositol-3 (PI3) kinase pathway in COX-2 expression has attracted attention. We investigated COX-2 expression, PI3 kinase activity, and the phosphorylation level of Akt, a downstream effector of PI3 kinase, in the human skin cancer cell line HSC-5. Compared to the nontumorigenic keratinocyte HaCaT, in HSC-5 cells, COX-2 protein expression and PI3 kinase activity were increased. The PI3 kinase inhibitor LY294002 reduced COX-2 expression in HSC-5 cells and, contrary to our expectation, the phosphorylation of Akt was significantly decreased. The expression of Bcl-2, which is regulated by Akt, was reduced, and apoptosis was induced in HSC-5 cells compared to HaCaT cells. COX-2 inhibitor NS398 up-regulated Akt phosphorylation. These results imply that constitutively over-expressed COX-2 down-regulates the Akt phosphorylation through a negative feedback mechanism.
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PMID:Negative feedback regulation of phosphatidylinositol 3-kinase/Akt pathway by over-expressed cyclooxygenase-2 in human epidermal cancer cells. 1549 14

The biological activities of Moxa, used as moxibustion, have not been well documented. We investigated here Moxa smoke for its tumor-specific cytotoxicity, anti-HIV activity, radical intensity and radical scavenging activity, in comparison with previously published data of Moxa extract. Moxa smoke showed slightly higher cytotoxicity against human tumor cell lines (oral squamous cell carcinoma HSC-2, HSC-3, promyelocytic leukemia HL-60) than against normal oral cells (gingival fibroblast HGF, pulp cell HPC, periodontal ligament fibroblast HPLF), yielding a tumor specificity index of 1.29. Moxa smoke dose-dependently induced internucleosomal DNA fragmentation, activation of caspases 3, 8 and 9, and slightly modified the expression of apoptosis-related proteins (Bcl-2, Bad, Bax) in HL-60 cells, but to much lesser extents than attained by positive controls (UV irradiation, actinomycin D treatment). ESR spectroscopy showed that Moxa smoke generated semiquinone-type radicals under alkaline conditions, and scavenged O2(-), hydroxyl radical, singlet oxygen and NO. All Moxa smoke preparations showed no apparent anti-HIV activity. These data demonstrate the antitumor potential of Moxa smoke.
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PMID:Cytotoxicity and radical modulating activity of Moxa smoke. 1579 3

Doxorubicin (adriamycin), an anthracycline antibiotic, showed higher cytotoxic activity against human tumor cell lines (oral squamous cell carcinoma HSC-2, HSC-3, submandibular gland carcinoma HSG, promyelocytic leukemia HL-60) than against normal human cells (gingival fibroblast HGF, pulp cell HPC, periodontal ligament fibroblast HPLF). Doxorubicin activated caspases 3, 8 and 9 in both HSC-2 and HL-60 cells, but induced internucleosomal DNA fragmentation only in HL-60 cells. Western blot analysis showed that doxorubicin did not significantly change the intracellular concentration of Bcl-2, Bax and Bad in HL-60 cells. Real-time PCR analysis showed that HPC cells expressed the highest amount of mdr1 mRNA, followed by HSC-2 > HGF > HSC-3 > HPLF > HSG > HL-60. ESR spectroscopy showed that doxorubicin produced no discernible radical under alkaline conditions (pH 7.4 to 10.5) except at pH 12.5, and it did not scavenge O2-, NO and DPPH radicals. The present study demonstrates that doxorubicin induces the tumor-specific cytotoxicity and some, but not all, apoptosis markers possibly by a radical-independent mechanism, and that mdr1 expression in the tumor cells is not related to the tumor specificity of doxorubicin.
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PMID:Induction of tumor-specific cytotoxicity and apoptosis by doxorubicin. 1586 24

The aim of our study was to clarify the apoptosis pathway induced by aloe emodin, an hydroxyanthraquinone present in aloe vera leaves, in rat hepatic stellate cells transformed by simian virus 40 (t-HSC/Cl-6), which retain the features of activated rat stellate cells. Apoptosis was determined by DNA fragmentation, caspase activity assay and western blotting analysis. Treatment of t-HSC/Cl-6 cells with 12.5, 25, or 50 microM aloe emodin inhibited t-HSC/Cl-6 cell viability in a dose- and time-dependent manner. The induction of apoptosis by aloe emodin was confirmed by typical DNA ladder formation and annexin v-propidium iodide flow-cytometric analysis. Aloe emodin treatment of t-HSC/Cl-6 cells caused activation of caspase-3 and caspase-9, detected with a caspase activity assay, although no change was observed in caspase-8 activity. Western blotting showed caspase-3 and caspase-9 active forms and the subsequent proteolytic cleavage of poly(ADP-ribose) polymerase. Aloe emodin induced mitochondrial membrane depolarization. Our data also show that cytochrome c increased in the cytosol but decreased in the mitochondria in a time-dependent manner. Increased Bax and unchanged Bcl-2 levels resulted in an increased Bax/Bcl-2 ratio. Thus, our research provides evidence that aloe emodin-induced apoptosis involves a mitochondria-associated apoptosis pathway.
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PMID:Aloe emodin-induced apoptosis in t-HSC/Cl-6 cells involves a mitochondria-mediated pathway. 1591 Apr 15

In search of compounds which show tumor-specific cytotoxic activity, two 3,5-dibenzoyl-1, 4-dihydropyridines (GB5, GB12) were found to show one or two orders higher cytotoxic activity against human tumor cell lines (squamous cell carcinoma HSC-2, HSC-3, submandibular gland carcinoma HSG, promyelocytic leukemia HL-60) than human normal cells (gingival fibroblast HGF, pulp cells HPC, periodontal ligament fibroblasts HPLF). GB5 and GB12 weakly induced several apoptosis-associated properties, such as internucleosomal DNA fragmentation, and activation of caspases -3, -8 and -9, in both HL-60 and HSC-2 cells. Western blot analysis showed that GB5 and GB12 transiently increased the expression of both anti-apoptotic protein (Bcl-2) and proapoptotic proteins (Bax and Bad) in HL-60 cells. ESR spectroscopy showed these compounds did not produce any detectable amount of radicals, nor scavenged superoxide (generated by hypoxanthine-xanthine oxidase reaction) or nitric oxide (generated by 1-hydroxy-2-oxo-3-(N-3-methyl-3-aminopropyl)-3-methyl-1-triazene), suggesting that the induction of cytotoxic action is not via a radical-mediated reaction. The present study suggests that GB5 and GB12 may induce non-apoptotic cell death in tumor cell lines.
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PMID:Tumor-specific cytotoxicity of 3,5-dibenzoyl-1,4-dihydropyridines. 1615 41

A total of eleven stilbenes [1-6] and flavonoids [7-11] were investigated for their tumor- specific cytotoxicity and apoptosis-inducing activity, using four human tumor cell lines (squamous cell carcinoma HSC-2, HSC-3, submandibular gland carcinoma HSG and promyelocytic leukemia HL-60) and three normal human oral cells (gingival fibroblast HGF, pulp cell HPC, periodontal ligament fibroblast HPLF). All of the compounds, especially sophorastilbene A [1], (+)-alpha-viniferin [2], piceatannol [5], quercetin [9] and isoliquiritigenin [10], showed higher cytotoxicity against the tumor cell lines than normal cells, yielding tumor-specific indices of 3.6, 4.7, >3.5, >3.3 and 4.0, respectively. Among the seven cell lines, HSC-2 and HL-60 cells were the most sensitive to the cytotoxic action of these compounds. Sophorastilbene A [1], piceatannol [5], quercetin [9] and isoliquiritigenin [10] induced internucleosomal DNA fragmentation and activation of caspases -3, -8 and -9 dose-dependently in HL-60 cells. (+)-alpha-Viniferin [2] showed similar activity, but only at higher concentrations. All the compounds failed to induce DNA fragmentation and activated caspases to much lesser extents in HSC-2 cells. Western blot analysis showed that sophorastilbene A [1], piceatannol [5] and quercetin [9] did not induce any consistent changes in the expression of pro-apoptotic proteins (Bax, Bad) and antiapoptotic protein (Bcl-2) in HL-60 and HSC-2 cells. An undetectable expression of Bcl-2 protein in control and drug-treated HSC-2 cells may explain the relatively higher sensitivity of this cell line to stilbenes and flavonoids.
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PMID:Tumor-specificity and apoptosis-inducing activity of stilbenes and flavonoids. 1615 45

Berberine iodide (IK-1) and acetoneberberine (IK-2) showed higher cytotoxicity against five human oral squamous cell carcinoma (HSC-2, HSC-3, HSC-4, NA, CA9-22) and one human promyelocytic leukemia (HL-60) cell lines, than against normal human oral tissue-derived cells (gingival fibroblast HGF, pulp cell HPC, periodontal ligament fibroblast HPLF), producing a tumor specificity index of 4.0 and 3.6, respectively. IK-1 was more potent than IK-2 in inducing the production of apoptotic cells, internucleosomal DNA fragmentation, the activation of caspases-3, -8 and -9, and the increased expression of proapoptotic BAD protein, with a corresponding decrease in the expression of anti-apoptotic Bcl-2 protein in HL-60 cells. These compounds did not induce internucleosomal DNA fragmentation (only producing larger DNA fragment), nor increased the Bad protein expression in HSC-2 cells. The present study demonstrated the tumor-specific cytotoxicity and apoptosis-inducing activity of berberines, suggesting their possible antitumor potentiaL
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PMID:Tumor-specific cytotoxicity and apoptosis-inducing activity of berberines. 1630 99

Three antitumor antibiotics, mitomycin C, bleomycin sulfate and peplomycin sulfate, were compared for their tumor-specific cytotoxicity, using human oral squamous cell lines (HSC-2, HSC-3, HSC-4, Ca9-22 and NA), human promyelocytic leukemic cell line HL-60 and human normal oral cell types (gingival fibroblast HGF, pulp cell HPC and periodontal ligament fibroblast HPLF). Among these three compounds, mitomycin C showed the highest tumor-specificity, due to its higher cytotoxic activity against human oral tumor cell lines than bleomycin and peplomycin. However, there was considerable variation of drug sensitivity among the six tumor cell lines. Mitomycin C induced internucleosomal DNA fragmentation and caspase-3, -8 and -9 activation in HL-60 cells only after 24 h. On the other hand, mitomycin C induced no clear-cut DNA fragmentation in HCS-2 cells, although it activated caspase-3, -8 and -9 to a slightly higher extent. Western blot analysis demonstrated that mitomycin C did not induce any apparent change in the intracellular concentration of anti-apoptotic protein (Bcl-2) and pro-apoptotic proteins (Bax, Bad). Electron microscopy of mitomycin C-treated HL-60 cells showed intact mitochondria (as regards to integrity and size) and cell surface microvilli, without production of an apoptotic body or autophagosome, at an early stage after treatment. The present study suggests the incomplete induction of apoptosis or the induction of another type of cell death by mitomycin C treatment.
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PMID:Re-evaluation of tumor-specific cytotoxicity of mitomycin C, bleomycin and peplomycin. 1709 55

The purpose of this study was to determine whether phosphatidylinositol 3-kinase (PI 3-K) inhibitors could modulate the apoptotic activity of the anticancer drugs cisplatin, 5-fluorouracil or docetaxel in an oral squamous cell carcinoma (OSCC) cell line, HSC-2. In preliminary experiments, cisplatin, 5-fluorouracil and docetaxel inhibited the proliferation of OSCC cells in a dose-dependent manner. We found that two PI 3-K inhibitors, wortmannin and LY294002, markedly suppressed the phosphorylation of Akt in OSCC cells. Treatment of OSCC cells with PI 3-K inhibitors significantly enhanced cisplatin-, 5-fluorouracil- or docetaxel-induced apoptosis. Caspase-3 and -9 inhibitors, but not a caspase-8 inhibitor, reduced anticancer drug-mediated apoptosis in PI 3-K inhibitor-treated OSCC cells, suggesting that the apoptotic pathway induced by the combination of anticancer drug therapy and PI 3-K inhibition may be functionally related to the intrinsic apoptotic pathway in OSCC cells. Expression of Bcl-2, cellular inhibitor of apoptosis protein-1 (cIAP-1), and X-linked IAP was down-regulated, and expression of Bax was up-regulated by PI 3-K inhibitors, while that of Bcl-xL, Bak and cIAP-2 was not attenuated. We also found that Bad phosphorylation was down-regulated by PI 3-K inhibitors. These results suggested that inhibition of PI 3-K enhances the susceptibility of OSCC cells to anticancer drug-mediated apoptosis through regulation of expression and post-translational modification of both pro- and anti-apoptotic proteins. These findings could potentially lead to new strategies for improving the efficacy of anticancer drugs in OSCC cells.
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PMID:Enhanced susceptibility to apoptosis of oral squamous cell carcinoma cells subjected to combined treatment with anticancer drugs and phosphatidylinositol 3-kinase inhibitors. 1791 41


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