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)

Human ovarian carcinomas express the CA-125, HER2/neu, and MUC1 tumor-associated Ags as potential targets for the induction of active specific immunotherapy. In the present studies, human ovarian cancer cells were fused to human dendritic cells (DC) as an alternative strategy to induce immunity against known and unidentified tumor Ags. Fusions of ovarian cancer cells to autologous DC resulted in the formation of heterokaryons that express the CA-125 Ag and DC-derived costimulatory and adhesion molecules. Similar findings were obtained with ovarian cancer cells fused to allogeneic DC. The fusion cells were functional in stimulating the proliferation of autologous T cells. The results also demonstrate that fusions of ovarian cancer cells to autologous or allogeneic DC induce cytolytic T cell activity and lysis of autologous tumor cells by a MHC class I-restricted mechanism. These findings demonstrate that fusions of ovarian carcinoma cells and DC activate T cell responses against autologous tumor and that the fusions are functional when generated with either autologous or allogeneic DC.
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PMID:Fusions of human ovarian carcinoma cells with autologous or allogeneic dendritic cells induce antitumor immunity. 1090 82

The U6 expression system was explored for efficient expression of a ribozyme against the human proto-oncogene c-neu. A hammerhead ribozyme (neuRz) and the control mutant ribozyme (MRz) were targeted to cleave c-neu mRNA at the tyrosine kinase domain. In vitro cleavage showed that neuRz was very active while MRz was not. Near-maximal target cleavage observed at a low ribozyme:target ratio (0.1) suggests that neuRz has good activity and turnover capability under physiological conditions, i.e., <5 mM MgCl(2) and 37 degrees C. Chimeric U6 ribozyme was expressed at about 5 x 10(6) copies/cell at 48 h in the ovarian carcinoma cell line SKOV-3.ip1. Partial down-regulation of c-neu mRNA and protein was observed in a dose-dependent manner in cells transiently transfected with U6neuRz- but not with MRz-containing plasmid. Sorted transient transfectants demonstrated dramatic growth inhibition with the neuRz-expressing cells. Our results demonstrate that the U6 expression system is very efficient and suitable for the expression of a hammerhead ribozyme. Moreover, nonviral delivery of the neuRz-expressing plasmid resulted in specific down-regulation of c-neu and, subsequently, growth inhibition of ovarian cancer cells overexpressing c-neu.
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PMID:Specific down-regulation of HER-2/neu mediated by a chimeric U6 hammerhead ribozyme results in growth inhibition of human ovarian carcinoma. 1123 73

Several new cytotoxic agents with activity in relapsed ovarian cancer are being combined with paclitaxel plus platinum as the first step to assess their impact in randomized trials against the standard treatment. These include topotecan, gemcitabine, epirubicin, and liposomal doxorubicin. Because of overlapping toxicities, there have been challenges in combining some of these agents in full dose with combination paclitaxel plus platinum. These have been overcome by use of sequenced administration. In addition to these new agents, novel non-cytotoxic drugs targeting specific signaling molecules or the tumor microenvironment provide additional avenues for clinical investigation. Many of these agents are rational to assess in ovarian cancer where laboratory research has pinpointed a number of alterations in molecules involved in cell signaling and cell cycle control. Examples include the antibody to HER 2/neu, agents targeting protein kinase C alpha, the p53 gene, and matrix metalloproteinase inhibitors. The challenges facing their assessment include how to determine adequate dosing when toxic effects are minimal and how to assess evidence of antitumor activity, short of conducting randomized studies. Finally, how best to use such agents together with conventional chemotherapy, in combination or in sequence, is unknown. Large clinical studies with some of these agents will provide some answers to their impact and how best to use them in the first-line management of advanced epithelial ovarian cancer.
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PMID:New cytotoxics and non-cytotoxics in epithelial ovarian cancer. 1124 Jul 31

In solid tumors, such as breast and ovarian cancer, the predominant genetic mechanism for oncogene activation is through gene amplification. The HER-2 (also known as ErbB2/c-erbB2/HER-2 / neu) oncogene is the most frequently amplified oncogene in breast cancer and its overexpression is associated with poor clinical outcome. In addition to its role in tumor progression, HER-2 has been implicated in altering tumor cell chemosensitivity to cytotoxic chemotherapy, particularly to anthracyclines. However, sophisticated in vitro studies have recently indicated that HER-2 may not have anything to do with the sensitivity of the cancer cells to cytotoxic drugs. Topoisomerase IIalpha gene is a target gene for many cytotoxic drugs and is located just by the HER-2 at the 17q12-q21. TopoIIalpha amplification and deletion may account for both relative chemosensitivity and resistance to anthracycline-therapy depending on the specific genetic defect at the topoIIalpha locus. Whereas HER-2 is an oncogene that clearly can drive tumor induction and growth, its function as a marker for chemoselection may be due to associated genetic changes in the topoIIalpha gene. Copyright 2000 Harcourt Publishers Ltd.
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PMID:Effects of HER-2/neu on chemosensitivity of tumor cells. 1149 99

The relatively high incidence of amplification and overexpression of the neu (c-erb B2/HER-2) oncogene in breast cancer, and its association with poor prognosis, particularly in node negative patients, may allow identification of patients who require aggressive therapy to prevent an early relapse. It's association with ovarian cancer, however, is less well defined than in breast cancer. An ELISA for the c-neu proto-oncogene related protein, p185, has been developed recently using the monoclonal antibodies NB3 and TA1. In the first study of it's kind, we assayed serum samples from patients with primary epithelial ovarian cancer for circulating c-neu p185. Elevated levels were found in 21/178 (11.8%) patients. No correlation was found between serum levels and either the presence or volume of tumor, when assessed either after primary or at second-look surgery. A change in c-neu p185 levels did not correlate with response to chemotherapy. When subjected to univariate and multivariate analyses together with other known prognostic factors, serum c-neu p185 was not a significant predictor of progression-free survival or overall survival. Although c-neu p185 may be involved in the pathogenesis of ovarian cancer, it's assay in serum has no value in prognosis or monitoring.
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PMID:Investigation of the c-neu proto-oncogene related protein, p185, in the serum of primary epithelial ovarian cancer patients. 1157 48

The immunohistochemical expression of HER-2/neu and cytofluorimetric data were retrospectively analyzed in a group of primary advanced ovarian cancers. Thirty-three out of 94 (35%) cases showed a specific p185/neu immunoreaction. No correlation between p185/neu expression and any of the clinico-pathologic parameters examined was observed. As far as cytofluorimetric data are concerned, 38 out of 69 (55%) of the tumors were diploid (DNA index = 1) while 31 (45%) were aneuploid (DNA index from 1.10 to 2.50 with a median value of 1.50). Ovarian tumors were defined as of low and high S-phase fraction in 68% and 32% of the cases, respectively. Tumor ploidy and S-phase fraction did not correlate with the clinico-pathologic characteristics or p185/neu oncoprotein expression. Aneuploid tumors had a higher S-phase fraction (mean: 15.81 +/- 13.44) than diploid tumors (mean: 8.89 +/- 7.98) (P < 0.01). p185/neu expression failed to affect significantly both overall and progression free survival. On the other hand tumor ploidy was found to be related to the prognosis of advanced ovarian cancer patients although the difference was not statistically significant. As far as progression free survival is concerned, the median time to recurrence was not reached for diploid cases whereas it was 21 months for aneuploid cases (P < 0.05). The 5-year survival for patients with a low S-phase fraction (58%) was significantly higher than for patients with high S-phase fraction tumors (28%) (P < 0.01). Median time to recurrence was 48 and 17 months for low and high S-phase fraction tumor patients, respectively (P < 0.05). However, in a multivariate analysis both tumor ploidy and S-phase fraction did not retain their prognostic value. The assessment of the role of the parameters examined in improving the prognostic characterization of ovarian cancer patients should be investigated in large multicenter clinical trials.
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PMID:Expression of HER-2/neu oncoprotein, DNA-ploidy and S-phase fraction in advanced ovarian cancer. 1157 57

Overexpression of the HER2/neu oncogene is a frequent molecular event in multiple human cancers including breast and ovarian cancer. Patients with breast cancer that overexpress HER2/neu have a poor prognosis, shorter relapse time, and low survival rate. In this report, the biologic signaling pathway mediated by HER2/neu tyrosine kinase receptor will be discussed. The mechanisms leading to transformation and tumorigenesis of HER2/neu-overexpressing cells will also be addressed. Treatments that target HER2/neu expression in cancer cells have been shown to be useful strategies to significantly reverse the malignancy induced by HER2/neu overexpression. In this report we will summarize strategies for targeting the HER2/neu gene, including targeting the gene product p185 oncoprotein, or transcriptional downregulation through the oncogene promoter. These fundamental studies, performed by different groups, warrant the clinical potential of targeting HER2/neu in cancer therapy.
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PMID:HER2 overexpression and cancer targeting. 1170 3

Targeted Genetics is developing, tgDCC-E1A, a E1A tumor suppressor gene therapy formulated in a non-viral, lipid-based delivery system as a potential treatment for solid tumors which overexpress the her-2/neu oncogene [221611]. Fournier is the European development partner [244180]. Preclinical studies of E1A in mouse models for human breast and ovarian cancer demonstrated inhibition of expression of the her-2/neu oncogene, a significant reduction in tumors and increased survival rate in the treated animals [244180]. Results of a phase I study of intratumoral liposomal-E1A gene therapy in patients with recurrent/refractory breast cancer and head and neck cancer were presented at the 1998 American Society of Clinical Oncology (ASCO) meeting. Results demonstrated that intratumoral delivery of the E1A gene caused a subsequent downregulation of HER-2/neu expression and tumor response. The phase I dose-escalation study treated nine patients with recurrent breast cancer and nine patients with head and neck cancer. In 16 patients evaluable for response, nine had stable disease, five had progressive disease and two had minor responses despite tumor progression at other sites. In one of six patients who had repeat biopsies of treated tumors, no pathological evidence of tumor was found. In four of seven patients evaluated to date (May 1998), evidence of downregulation of HER-2/neu was reported [287387,290118]. The first phase I trial in patients with breast and ovarian cancer was completed by the end of 1997. The second phase I trial, enrolling 12 to 24 patients with solid tumors, was initiated in April 1997. Its aim was to determine dosing and safety of tgDCC-E1A and evaluate levels of gene transfer and tumor response. Patients were administered tgDCC-E1A by intratumoral injections. The company completed this trial by the end of 1997. In October 1998, Targeted Genetics initiated a multicenter, open-label phase II clinical trial of tgDCC-E1A in patients with recurrent head and neck squamous cell carcinoma who have exhibited disease progression despite standard therapies. The study to be conducted at six medical institutions in the US will enrole up to 60 patients with an interim analysis scheduled to be performed after the first 20 evaluable patients have been enrolled. Patients will be treated with ten direct intratumoral injections of the E1A gene over a period of 8 weeks, with follow-up performed at week 12. Patients who demonstrate a response will be eligible for continued treatment and will be monitored for 1 year [300424]. Targeted Genetics has issued three patents covering methods and compositions of use of the E1A and LTgenes (qv) to treat a variety of cancers. US-05651964 covers the use of the E1A gene, US-05643567 and US-05641484 cover the use of either the E1A gene or the LT gene as cancer therapies. These three patents provide the company with broad patent protection for tgDCC-E1A and all future products based on the use of the E1A or LT gene as tumor suppressors [259808].
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PMID:Technology evaluation: tgDCC-E1A, targeted genetics/MD Anderson. 1171 50

During the past decade there has been renewed interest in the use of vaccine immunotherapy for the treatment of cancer. This review focuses on HER2/neu, a tumour-associated antigen that is overexpressed in 10-40% of breast cancers and other carcinomata. Several immunogenic HER2/neu peptides recognized by T lymphocytes have been identified to be included in cancer vaccines. Some of these peptides have been assessed in clinical trials of patients with breast and ovarian cancer. Although it has been possible to detect immunological responses against the peptides in the immunized patients, no clinical responses have so far been described. Immunological tolerance to self-antigens like HER2/neu may limit the functional immune responses against them. It will be of interest to determine whether immune responses against HER2/neu epitopes can be of relevance to cancer treatment.
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PMID:Update on HER-2 as a target for cancer therapy: HER2/neu peptides as tumour vaccines for T cell recognition. 1173 93

Overexpression of the HER2/neu oncogene (also known as c-erbB2) is a frequent molecular event in multiple human cancers, including breast and ovarian cancer. Patients with cancer that overexpress HER2/neu are associated with unfavorable prognosis, shorter relapse time, and low survival rate. Treatments that target HER2/neu expression in cancer cells have been shown to be useful strategies to significantly reverse the malignancy induced by HER2/neu overexpression. The humanized anti-HER2/neu antibody, trastuzumab (Herceptin; Genentech, Inc, South San Francisco, CA) has proven to be effective in clinical trials in patients with metastatic breast cancer. In addition, tyrosine kinase inhibitors such as emodin can also target the HER2/neu oncogenic activity. Emodin treatment inhibits HER2/neu tyrosine kinase activity and preferentially suppresses the transformation of HER2/neu-overexpressing breast cancer cells. Emodin also sensitizes HER2/neu-overexpressing cancer cells to chemotherapeutic agents, including cisplatin, doxorubicin, etoposide, and paclitaxel. Alternatively, HER2/neu overexpression can be repressed by attenuating the promoter activity of the HER2/neu gene. We have identified a number of potent transcriptional regulators, including the ets family member PEA3 and the adenovirus type 5 E1A, which are able to repress HER2/neu gene expression. Expression of these transcriptional regulators resulted in downregulation of HER2/neu promoter activity and reversed the transformed phenotype of the cancer cells in vitro. In vivo studies show that these HER2/neu repressors can act therapeutically as tumor suppressor genes for tumors that overexpress HER2/neu. These preclinical studies clearly indicate that transcriptional repressors that downregulate HER2/neu can be effective regimens for cancer treatment in a gene therapy format. More importantly, the tumor-free survival rate of treated animals is dramatically increased under nontoxic doses compared with untreated animals. A phase I clinical trial using E1A-liposome in breast and ovarian patients has recently been completed. Following treatment, we observed downregulation of the HER2/neu protein accompanied by E1A expression in both cancer and noncancer cells. Numbers of tumor cells in the pleural effusion or ascites were found to be dramatically reduced after treatment. Furthermore, apoptosis was strongly induced in the tumor cells. A phase II study has been started to further evaluate therapeutic efficacy and tumor suppression mechanisms of E1A. These studies show the clinical potential of targeting HER2/neu in cancer therapy.
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PMID:Targeting HER2: recent developments and future directions for breast cancer patients. 1177 2


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