Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C1140680 (ovarian cancer)
 28,141 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To clarify the significance of the Fas antigen (Ag) in gynecologic tumors, its expression in gynecologic cancer cell lines was examined. The Fas Ag was expressed in 6 of 15 cell lines. Five of 8 ovarian cancer cell lines but none of 4 choriocarcinoma cell lines expressed the Fas Ag. In drug-resistant cell lines derived from one of the Fas-positive cells, its expression was not lost after development of resistance to cisplatin, SN-38 or etoposide, but its expression was absent in the cell line resistant to Adriamycin. The effect of the anti-Fas antibody (Ab) was then studied. Apoptosis was induced in 7 of 9 Fas-positive cell lines, whereas the remaining two cell lines were unaffected. Furthermore, the combination effect of the anti-Fas Ab and drugs was examined in an ovarian cancer cell line and its drug-resistant variants, and a synergistic effect was observed. These results suggest important roles of the Fas Ag in ovarian cancer and the potential for overcoming drug resistance by a combination of the anti-Fas Ab and various drugs.
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PMID:Combination effect of anti-Fas antibody and chemotherapeutic drugs in ovarian cancer cells in vitro. 897 93

We compared the sensitivities to apoptosis via anti-Fas antibody of two human ovarian cancer cell lines, NOS4 and SKOV-3, both of which strongly express the Fas antigen on their cell surface. Treatment with anti-Fas antibody induced extensive DNA fragmentation in NOS4 cells but none in SKOV-3 cells. However; both cell lines underwent apoptosis in response to calcium ionophore A23187 or sphingomyelinase, demonstrating that the latter cell line is capable of DNA fragmentation. DNA fragmentation was not induced in either cell line by treatment with PKC activator PMA, however treatment with protein kinase C (PKC) inhibitor H-7 induced extensive DNA fragmentation in NOS4 cells, but again none in SKOV-3 cells. Protein kinase A inhibitor HA1004 treatment did not induce DNA fragmentation in either cell line. Correspondingly, treatment of cells with PMA before anti-Fas antibody or A23187 treatment partially inhibited induction of DNA fragmentation in NOS4 cells but not in SKOV-3 cells. Both NOS4 and SKOV-3 cell lines expressed isozymes of PKC at comparable levels. These results suggest the presence of a PKC-dependent anti-apoptotic mechanism in association with high sensitivity to anti-Fas antibody in these ovarian cancer cell lines.
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PMID:Protein kinase C-dependent anti-apoptotic mechanism that is associated with high sensitivity to anti-Fas antibody in ovarian cancer cell lines. 1040 49

Several endogenous or viral inhibitors of apoptosis, including Bcl-2, Bcl-xL, FLIP, p35, and CrmA, have been shown to be cleaved by caspases during apoptosis. In this study, we demonstrate that the endogenous inhibitor of apoptosis, hILP/XIAP, is also cleaved in apoptotic T lymphocytes, generating at least one prominent fragment of 29 kDa. This p29 cleaved fragment was detected in Jurkat cells induced to apoptose by anti-Fas antibody, staurosporin, or VP-16. The cleavage of hILP appears to be caspase mediated because the production of the p29 protein was inhibited by the pan-caspase peptide inhibitor, Z-VAD.FMK. In Jurkat cells engineered to overexpress CrmA, cleavage of hILP in response to anti-Fas antibody or staurosporin was inhibited, whereas overexpression of Bcl-2 abrogated the cleavage in response to VP-16. Cleavage of hILP was also observed in cell-free reactions using in vitro translated hILP and recombinant caspase-3 or -7. Moreover, we found that the p29 hILP fragment retained the ability to bind caspase-3 and -7, as shown previously for full-length or BIR-2 hILP. The p29 cleavage product was also detected during T-cell receptor-mediated apoptosis in peripheral blood lymphocytes from normal donors. Furthermore, tumor-associated T lymphocytes purified from ascites of patients with ovarian cancer expressed fragmented hILP, which was not detected in control T cells purified from peripheral blood of normal donors. Our results suggest that the cleavage of hILP represents an important event in apoptosis of T lymphocytes in both normal and pathological in vivo settings.
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PMID:Inhibitor of apoptosis protein hILP undergoes caspase-mediated cleavage during T lymphocyte apoptosis. 1076 65

The increasing number of factors to be taken into account in the oestrogen transcriptional process has created a need to develop a rapid screening method to evaluate their role in physiology and pathology. Molecular biology techniques enable gene expression studies at the mRNA level with small amounts of tissues. We therefore developed a semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) technique using fluorescent oligonucleotides to analyse simultaneously a large panel of interrelated genes involved in the oestrogen transcriptional pathway using a moderately expressed housekeeping gene, the hypoxanthine phosphoribosyltransferase gene (HPRT), as the reference gene. Expression levels of oestrogen receptors (ERalpha, ERbeta), cofactors AIB1, RIP140, SMRT and the Fas-associated protein-tyrosine phophatase-1 (FAP-1) genes were evaluated in breast, endometrial and ovarian cancer cell lines and in three ERalpha-positive and three ERalpha-negative breast cancer tumours. This technique provides a rapid and reliable way to quantitate simultaneously numerous mRNAs of genes involved in the oestrogen pathway from small amounts of tissues.
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PMID:Semiquantitative reverse transcription-polymerase chain reaction to evaluate the expression patterns of genes involved in the oestrogen pathway. 1082 36

The BRCA1 tumor suppressor gene has previously been implicated in induction of high levels of apoptosis in osteocarcinoma cell lines. Overexpression of BRCA1 was shown to induce an apoptotic signaling pathway involving the c-Jun N-terminal kinase (JNK), but the signaling steps upstream and downstream of JNK were not delineated. To better understand the role of BRCA1 in apoptosis, we examined the effect of wild-type and C-terminal-truncated dominant negative BRCA1 on breast and ovarian cancer cell lines subjected to a number of different pro-apoptotic stimuli, including growth factor withdrawal, substratum detachment, ionizing radiation, and treatment with anticancer agents. All of these treatments were found to induce substantial levels of apoptosis in the presence of wild-type BRCA1, whereas dominant negative BRCA1 truncation mutants diminished the apoptotic response. Subsequent mapping of the apoptotic pathway induced by growth factor withdrawal demonstrated that BRCA1 enhanced signaling through a pathway that sequentially involved H-Ras, MEKK4, JNK, Fas ligand/Fas interactions, and caspase-9 activation. In addition, the pathway functioned independently of the p53 tumor suppressor. These data suggest that BRCA1 is an important modulator of the response to cellular stress and that loss of this apoptotic potential due to BRCA1 mutations may contribute to tumor development.
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PMID:BRCA1 facilitates stress-induced apoptosis in breast and ovarian cancer cell lines. 1093 85

Cytotoxic drugs commonly used in cancer therapy promote tumor cell death by inducing apoptosis, but the cell death pathway(s) is likely dependent on the mechanism of drug action. In the present study, we investigated the mechanisms of cell death induced by doxorubicin (DXR) and the novel disaccharide anthracycline MEN 10755, in a human ovarian cancer cell line (A2780). Exposure to either anthracycline induced the up-regulation of several genes known to promote cell cycle arrest and DNA repair (WAF1/p21, GADD45) or apoptosis (bax, Fas). Although the expression of Fas was increased, an antagonistic anti-Fas antibody ZB4 did not inhibit anthracycline-induced apoptosis, suggesting that the stimulation of the Fas receptor did not play a critical role in the induction of apoptosis in this cell line. We also observed that neither MEN 10755 nor DXR were able to induce apoptosis in A2780 cells deprived of the nucleus but retaining an intact mitochondrial function (cytoplasts) and that apoptosis induced by either anthracycline was inhibited by cycloheximide, indicating that it is an active process requiring new protein synthesis. Both the caspases inhibitors, ZVAD-fmk and DEVD-cho, inhibited at similar extent apoptosis induced by either DXR or MEN 10755, suggesting an involvement of caspase-3 in this response. We conclude that, in a tumor cell line of epithelial origin, the apoptosis following exposure to anthracyclines is an active process requiring protein synthesis and drug interaction with nuclear structures. The pathway was Fas-independent but likely involved bax and caspase-3 as effectors of the cascade culminating in apoptosis.
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PMID:Apoptotic events in a human ovarian cancer cell line exposed to anthracyclines. 1116 Jun 8

We found that a short synthetic peptide corresponding to the "antisense homology box" of Fas ligand induced apoptotic cell death of Fas-expressing human ovarian cancer cell lines. The peptide was deduced from residues 256-265 of human Fas ligand, based on the hypothesis that it should contain a specific binding site to the corresponding Fas. Interestingly, the ovarian cancer cell line NOS4, which was sensitive to anti-Fas antibody induced apoptosis, was not affected by the peptide, whereas another cell line, SKOV-3, which was insensitive to anti-Fas antibody, was killed by the peptide. Thus, this short peptide was shown to have a unique activity to induce apoptosis in human ovarian cancer cells in a manner different from anti-Fas antibody.
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PMID:A short peptide derived from the antisense homology box of Fas ligand induces apoptosis in anti-Fas antibody-insensitive human ovarian cancer cells. 1122 89

Fas-associated phosphatase-1 (FAP-1) is a protein-tyrosine phosphatase that binds the cytosolic tail of Fas (Apo1, CD95), presumably regulating Fas-induced apoptosis. Elevations of FAP-1 protein levels in some tumor cell lines have been correlated with resistance to Fas-induced apoptosis. To explore the expression of FAP-1 in ovarian cancer cell lines and archival tumor specimens, mouse monoclonal and rabbit polyclonal antibodies were generated against a FAP-1 peptide and recombinant FAP-1 protein. These antibodies were used for immunoblotting, immunohistochemistry, and flow-cytometry analysis of FAP-1 expression in the Fas-sensitive ovarian cancer lines HEY and BG-1, and in the Fas-resistant lines OVCAR-3 FR and SK-OV-3. All methods demonstrated high levels of FAP-1 in the resistant lines OVCAR-3 FR and SK-OV-3, but not in the Fas-sensitive lines HEY and BG-1. Furthermore, levels of FAP-1 protein also correlated with the amounts of FAP-1 mRNA, as determined by reverse transcriptase-polymerase chain reaction analysis. FAP-1 protein levels were investigated by immunoblotting in the National Cancer Institute's panel of 60 human tumor cell lines. Although FAP-1 failed to correlate with Fas-resistance across the entire tumor panel, Fas-resistance correlated significantly with FAP-1 expression (P: < or = 0.05) and a low Fas/FAP-1 ratio (P: < or = 0.028) in ovarian cancer cell lines. FAP-1 expression was also evaluated in 95 archival ovarian cancer specimens using tissue-microarray technology. FAP-1 was expressed in nearly all tumors, regardless of histological type or grade, stage, patient age, response to chemotherapy, or patient survival. We conclude that FAP-1 correlates significantly with Fas resistance in ovarian cancer cell lines and is commonly expressed in ovarian cancers.
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PMID:Expression and potential role of Fas-associated phosphatase-1 in ovarian cancer. 1129 May 51

Macrophages can kill tumor cells by releasing high levels of nitric oxide (NO) and related reactive nitrogen species such as nitroxyl and peroxynitrite, after up-regulation of expression of the inducible nitric oxide synthase gene (iNOS). In this paper we describe two novel human cell lines that are capable of expressing high levels of iNOS under the control of analogues of either the insect hormone ecdysone or tetracycline. We have entrapped these iNOS-expressing cells within a semipermeable alginate-poly-L-lysine membrane as a means of delivery to tumor sites in a nude mouse model. These encapsulated cells can be induced to generate sustainable high concentrations NO and reactive nitrogen species at tumor sites after treatment either with ponasterone A or muristerone A or with doxycycline. Delivery of these iNOS-expressing cells to tumors formed from human ovarian cancer SKOV-3 cells results in 100% killing, whereas treatment of tumors formed from human colon cancer DLD-1 cells results in 54% killing. We show that in these iNOS-expressing cells, tumor killing is associated with concomitant up-regulation of the Fas/FasL proteins.
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PMID:Microencapsulated iNOS-expressing cells cause tumor suppression in mice. 1177 48

Two ovarian cancer cell lines named NOS4 and SKOV-3 have been shown to have different sensitivities to a cytotoxic anti-Fas antibody, CH-11. Although both cell lines express Fas molecules on the cell surfaces at the same intensities, apoptosis is induced by CH-11 in NOS4 cells but not in SKOV-3 cells. In this study, the different apoptosis-sensitivities of these cells were assessed. Both cell lines express almost the same levels of FADD, RIP, c-FLIP, FAP-1, Bax, Bcl-2 and Bcl-XL. Evidence of caspase-8, caspase-9 and caspase-3 activation and of cleavage of PARP and Bid was obtained in NOS4 cells but not in SKOV-3 cells. When triggered by FasL protein, DNA fragmentation and caspase-8 activation were observed in SKOV-3 cells, though they were not as clear as in NOS4 cells. All the anti-Fas antibody-mediated signals for apoptosis induction in NOS4 cells were completely blocked by a caspase-8-specific inhibitor, Z-IETD-FMK. These results indicate that the different sensitivities to the anti-Fas antibody are solely dependent on the activation of caspase-8, which could be influenced by yet unknown qualitative or quantitative abnormalities in molecules involved in DISC formation.
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PMID:Activation of caspase-8 is critical for sensitivity to cytotoxic anti-Fas antibody-induced apoptosis in human ovarian cancer cells. 1186 94


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