Biomedical subjects
E Reed
Publications and source records attributed to E Reed.
Oxaliplatin, tetraplatin, cisplatin, and carboplatin: spectrum of activity in drug-resistant cell lines and in the cell lines of the National Cancer Institute's Anticancer Drug Screen panel.
The present study was designed to explore the activity of platinum compounds in cisplatin-resistant cell lines, the unselected cell lines of the National Cancer Institute's Anticancer Drug Screen, and the potential for use in combination. The activities of four platinum compounds in cisplatin-resistant KB and A2780 cells were investigated. The cells were highly resistant to cisplatin and cross-resistant to carboplatin, but less than one-tenth as resistant to oxaliplatin and tetraplatin. Cellular accumulation of all platinum compounds was decreased in both resistant cell lines. When the activities of cisplatin and oxaliplatin were evaluated in the National Cancer Institute's Anticancer Drug Screen, marked differences were observed. Evaluation of the activity profile using the COMPARE program revealed a different pattern for both agents: the cisplatin activity profile was similar to those of other diamine-platinum compounds, alkylating agents including melphalan, and camptothecin analogs, whereas the activity profile of oxaliplatin resembled those of other "dach" (diaminocyclohexane) platinum compounds and of acridine derivatives. The sensitivity profiles are influenced by the target(s)/mechanism(s) of action and the mechanism(s) of resistance of a drug. The dissimilarity in profiles suggests that these two platinum compounds have a different target(s)/mechanism(s) of action, a different mechanism(s) of resistance, or most likely both. Studies evaluating combinations of cisplatin/oxaliplatin suggest that the activities of these two agents are at least additive and possibly synergistic. Oxaliplatin has a different spectrum of activity and low cross-resistance to cisplatin and should be valuable in cisplatin refractory patients or in combination with cisplatin.
Enhanced XPA mRNA levels in cisplatin-resistant human ovarian cancer are not associated with XPA mutations or gene amplification.
Enhanced expression of the nucleotide excision repair gene XPA is associated with resistance to cisplatin treatment in human ovarian cancer. Understanding the cause of enhanced XPA expression will provide new molecular targets for therapy directed at overcoming chemoresistance. Enhanced gene expression in cancer cells is often caused by mutations or gene amplification. Molecular analyses of the XPA genes in human ovarian cancers indicate that gene mutation and amplification are not the cause of enhanced XPA mRNA levels in ovarian cancers overexpressing XPA. Altered nucleotide excision repair (NER) gene regulation in chemoresistant tumors is discussed.
Sensitization by interleukin-1alpha of carboplatinum anti-tumor activity against human ovarian (NIH:OVCAR-3) carcinoma cells in vitro and in vivo.
Cytokines are directly cytotoxic to tumor cells in vitro and in vivo, and interleukin-1alpha (IL-1alpha) potentiates the cytotoxicity of a number of clinically active drugs in several human tumor cells, including carcinomas of the breast and ovary. In this study, we found that IL-1alpha potentiated the cytotoxicity of carboplatin in human ovarian NIH:OVCAR-3 cancer cells during simultaneous drug exposure in vitro. Human ovarian carcinoma NIH:OVCAR-3 cells are resistant to clinically relevant concentrations of chemotherapeutic agents, including cisplatin. Both carboplatin and IL-1alpha as single agents inhibited the growth of NIH:OVCAR-3 cells grown as xenograft in nude mice; however, carboplatin was more effective in delaying tumor growth, and this inhibition was dose-dependent. Treatment with IL-1alpha followed by carboplatin caused a significant delay in tumor growth, resulting in a significant enhancement (4-fold) of the anti-tumor effect of carboplatin. In vitro potentiation of carboplatin cytotoxicity by IL-1alpha did not involve formation of nitric oxide as IL-1 or combinations of IL-1 with carboplatin failed to modulate basal nitric oxide production in OVCAR-3 cells. Potentiation of the anti-tumor activity of carboplatin by IL-1alpha was due to a significant (3- to 4-fold) increase in the accumulation of total Pt in IL-1-treated tumor xenograft, resulting in a 2-fold increase in DNA-Pt adduct formation in these tumors. In contrast, IL-1alpha had no significant effect on DNA-Pt adduct formation in the kidney. The potent synergy of IL-1alpha and carboplatin in vitro and in vivo against ovarian carcinoma cells suggests that combinations of carboplatinum and interleukin-1alpha may be effective against this disease in the clinic.
Attention deficit hyperactivity disorder in a multigenerational pedigree.
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Clinical investigation of a cytostatic calcium influx inhibitor in patients with refractory cancers.
Carboxyamido-triazole (CAI) is a synthetic inhibitor of non-excitable calcium channels that reversibly inhibits angiogenesis, tumor cell proliferation, and metastatic potential. Inhibition of calcium influx and calcium-dependent events is a potential common mechanism underlying these effects of CAI. The cytostatic and antiangiogenic properties of CAI led to its development for clinical investigation. In a Phase I clinical trial open to patients with refractory solid tumors, 49 patients received p.o. administered CAI daily or every other day. Two oral formulations, PEG-400 CAI solution and a gelatin capsule containing CAI in PEG-400, were tested. All administered dosages of CAI yielded plasma concentration at or above the range demonstrated to be effective in inhibiting signaling and cancer progression in vitro and in preclinical models (1 microgram/ml, 2.3 microM). Toxicity of p.o. administered CAI most commonly consisted of dose-related grade 1-2 nausea, vomiting, and occasional anorexia. CAI administration at bedtime ameliorated gastrointestinal complaints in many patients; others required addition of simple antiemetic regimens, usually consisting of metoclopropamide or prochlorperazine. Gastrointestinal complaints were the cause for compliance-limiting toxicity at 175 mg/m2/day of the liquid formulation and 125 mg/m2/day of the gelatin capsule formation. Reversible and rare sensory axonal neuropathy (grade 3, 1 patient) and neutropenia (grade 4, 1 patient) were dose-limiting toxicities observed at the 330 mg/m2 every-other-day liquid CAI dose level. No evidence of cumulative end organ damage or central nervous system injury was observed. Disease stabilization and improvement in performance status was observed. Disease stabilization and improvement in performance status was observed in 49% of evaluable patients who had disease progression before CAI. Disease stabilization and associated improvement in performance status was seen in patients with renal cell carcinoma (7 months), pancreaticobiliary carcinomas (3, 5, and 5 months), melanoma (7 months), ovarian cancer (7 months), and non-small cell lung cancer (3 months). The recommended Phase II doses from this trial are 150 mg/m2/day in the liquid formation and 100 mg/m2/day in the gelatin capsule formation.
In vitro propagation and production of hepatitis E virus from in vivo-infected primary macaque hepatocytes.
Hepatitis E virus (HEV) is responsible for sporadic cases as well as large epidemics of acute viral hepatitis in many developing countries. The nucleotide sequence of HEV appears to be unique among known viruses and thus may represent a prototype human pathogen in a novel class of single-stranded, positive-sense RNA viruses. To facilitate further studies of the biology of HEV, a tissue culture system using a serum-free medium formulation has been developed to propagate the virus in vitro. Hepatocytes were isolated from livers of cynomolgus macaques experimentally infected with a HEV (Burma strain) inoculum and maintained in long-term cultures. Using a highly strand-specific RT-PCR assay, both the positive-sense and the negative replicative strands of HEV RNA were detected in these hepatocytes throughout the course of the experiments. Positive-strand genomic RNA was also detected in the culture medium, suggesting the production and secretion of HEV virus particles. The virus particles were successfully concentrated 200-fold from the medium using ultrafiltration, and they could be observed by immunoelectron microscopy using anti-HEV-positive immune serum. These results demonstrate the capacity of this hepatocyte culture system to replicate HEV in vitro, thus providing an experimental means to study the replicative process of the virus.
Chemotherapy plus local treatment in the management of intraocular retinoblastoma.
OBJECTIVE: To describe platinum-based chemotherapy combined with local treatment modalities as an alternative to external beam radiotherapy for intraocular retinoblastoma. DESIGN: Platinum levels were measured by atomic absorption analysis in the tumors of 2 patients with retinoblastoma given carboplatin 5 or 2.5 hours before enucleation. Platinum levels in heated vs nonheated Greene melanoma tumors in rabbits were compared. A retrospective review of 172 affected eyes in 136 consecutive patients treated for retinoblastoma between January 1990 and December 1995 was performed. From 1990 to 1992, all treatable eyes initially received systemic carboplatin, 560 mg/m2, followed by 15 to 30 minutes of continuous diode laser hyperthermia (thermochemotherapy). Since 1992, larger tumors were treated initially with 3 monthly cycles of carboplatin, etoposide, and vincristine sulfate to reduce tumor volume (chemoreduction) followed by sequential aggressive local therapy (SALT) during examinations under anesthesia every 2 to 3 weeks. OUTCOME MEASURE: Treatment success was defined as eradication of tumor without enucleation or external beam radiotherapy. RESULTS: Significant therapeutic platinum levels were measured in the human tumors 2.5 and 5 hours after carboplatin administration. Increasing the temperature by 9 degrees C for 15 minutes doubled platinum levels in the rabbit model. Of the 38 eyes with Reese-Ellsworth group 1 through 5b tumors that were treated primarily with thermochemotherapy, all 24 eyes with group 1 and 2 tumors were treated successfully and two of the 4 eyes with group 3 tumors and all 10 eyes with group 5b tumors were treated unsuccessfully. Chemoreduction plus SALT was the primary treatment in 35 eyes and was successful in all 10 eyes with group 1 through 4 tumors and unsuccessful in all 7 eyes with extensive subretinal seeding and all 18 eyes with group 5b tumors with vitreous seeding. Seventy patients received carboplatin or carboplatin, vincristine, and etoposide, with myelosuppression, occasionally associated with bacteremia, being the main side effect. Transfusions were required in 15% of patients. Radiation retinopathy occurred in all 6 eyes treated with iodine 125 plaques. CONCLUSIONS: Thermochemotherapy is successful primary treatment for Reese-Ellsworth group 1 and 2 retinoblastomas. For larger tumors in the absence of vitreous or extensive subretinal seeding, 3 cycles of chemoreduction followed by SALT eradicates residual viable tumor. Chemoreduction plus SALT was not successful in eyes with diffuse vitreous or extensive subretinal seeding. Prior chemotherapy increases the risk for radiation retinopathy following 125I plaque therapy. External beam radiotherapy can safely be avoided in the primary treatment of Reese-Ellsworth groups 1 through 4 nondispersed retinoblastoma.
Severe thrombocytopenia in patients treated with suramin: evidence for an immune mechanism in one.
Although suramin has long been used to treat human trypanosomiasis, recent clinical trials have tested its efficacy against the acquired immunodeficiency syndrome (AIDS) and various malignancies. Thromobocytopenia was observed in early trials with suramin in AIDS, but has been uncommon in patients treated for solid tumors. Here we describe 5 patients out of a total of 67 (7%) who developed severe thrombocytopenia while receiving suramin as part of a phase II clinical trial for metastatic prostate carcinoma refractory to hormonal therapy. IgG purified from one patient's plasma caused suramin-dependent platelet aggregation. There was also evidence of crossreactivity between suramin and heparin in this system. An immune mechanism, however, could not be documented in the other cases, suggesting that multiple mechanisms may be responsible for severe thrombocytopenia in this patient population.
Comparative analyses of relative ERCC3 and ERCC6 mRNA levels in gliomas and adjacent non-neoplastic brain.
Nucleotide excision repair (NER) is an ordered process in nonmalignant cells, in both human and nonhuman systems. We previously reported that in human brain there is discordant mRNA expression of excision repair cross-complementing (ERCC) 1 and ERCC2 in malignant tissues, concurrent with excellent concordance of these genes in nonmalignant tissues from the same patients. Here we have extended these studies to compare low-grade tumors to high-grade tumors and to include ERCC3 (which links DNA repair with DNA transcription) and ERCC6 (which is essential for gene-specific repair). Glial tumor and adjacent normal brain specimens from 19 individuals were studied. Paired malignant and nonmalignant tissues were obtained from 12 of these patients. For ERCC3, there was excellent concordance of mRNA expression between malignant and nonmalignant tissues from the same individuals (P = 0.003). For ERCC6, no concordance was observed (P = 0.314). Tumor tissue from patients with high-grade gliomas exhibited marked discordance of mRNA expression patterns in situations in which good concordance was observed in tumor tissue from low-grade gliomas. We previously established that malignant brain tumors show increased disorder of genes in the NER process, as compared with nonmalignant tissues. These data suggest that increasing disorder in the NER process may occur as cells move from low-grade to high-grade malignancy.
The relationship between borderline ovarian tumors and epithelial ovarian carcinoma: epidemiologic, pathologic, and molecular aspects.
Borderline ovarian tumors (BOT) are a low-grade form of ovarian malignancy with significantly less aggressive behavior than classical epithelial ovarian carcinoma (EOC). Yet, a subset of these tumors can progress and be lethal. Prognostic factors related to the development of BOT are similar to those for EOC. BOT with aneuploid DNA content have a worse prognosis; this trend is similar to that found in EOC. Patterns of loss of heterozygosity of some chromosomal abnormalities suggest that some, but not all BOT may evolve into more invasive tumors. Molecular biology has provided some clues to the pathogenesis of this entity. Increasing frequency of K-ras mutations are associated with EOC compared to BOT or benign lesions of the ovary. Platelet-derived growth factor and PDGF-alpha receptor are overexpressed in some BOT and EOC, but not in benign tumors or normal ovaries. These genetic markers suggest a closer relationship between a subset of BOT and invasive EOC. Further analysis of genetic abnormalities may delineate the relationship between BOT and EOC better, and will hopefully lead to a unifying hypothesis as to the origin of these important ovarian lesions.
A phase I study of paclitaxel and cyclophosphamide in recurrent adenocarcinoma of the ovary.
We have conducted a disease specific phase I study of paclitaxel and cyclophosphamide in recurrent adenocarcinoma of the ovary. This was done to take advantage of the cellular and molecular synergism between paclitaxel and DNA-damaging agents, with the hope of avoiding paclitaxel-cisplatin toxicities. Paclitaxel was given as a 24-hr CIVI, after which cyclophosphamide was given as a 60-min infusion. Cycles of therapy were repeated every 3 weeks; and granulocyte colony-simulating factor (G-CSF) was given in a "flexible" dosing fashion. Starting doses were 170 mg/m2 paclitaxel and 750 mg/m2 cyclophosphamide. Dose-limiting toxicity (DLT) was seen at the doses of 250 mg/m2 paclitaxel and 1250 mg/m2 cyclophosphamide. DLT was cumulative thrombocytopenia. There were six nonhematologic grade 3 or 4 toxicities experienced in the study. Eleven of 20 evaluable patients (55%) have achieved an objective response (4 CCR;7 PR). Three of four CCRs were confirmed by negative findings at peritoneoscopy. The median number of prior therapies was 2 (range 1-4) and 17 individuals had platinum-refractory disease. We conclude that paclitaxel followed by cyclophosphamide is an active combination in recurrent ovarian cancer and that further study is needed to determine if this combination is truly better than paclitaxel alone.
A phase I/II study of dose-intense paclitaxel with cisplatin and cyclophosphamide as initial therapy of poor-prognosis advanced-stage epithelial ovarian cancer.
Epithelial ovarian cancer patients with bulky residual tumor have a poor response to therapy and limited survival. We investigated the addition of dose-intense paclitaxel to cisplatin and cyclophosphamide for patients with FIGO III/IV epithelial ovarian cancer. Paclitaxel dose was intensified from 135 to 250 mg/m2 and administered in combination with cisplatin at > or = 75 mg/m2 and cyclophosphamide at 750 mg/m2. Thirty-one of 36 patients (86%) and 25 (70%) had > or = 2 and > or = 3 cm residual disease after surgery, respectively. One-third had stage IV disease, and 80% had grade 3 tumors. The maximally tolerated doses (MTD) were paclitaxel at 250 mg/m2, cisplatin at 75 mg/m2, and cyclophosphamide at 750 mg/m2 on a 21-day cycle with G-CSF, 10 micrograms/kg/day. Administered dose intensity at the MTD was > or = 86%. Reversible grade 3 peripheral neuropathy occurred in 28% of patients and fever during neutropenia in 2/352 cycles (0.5%). The pathologic response rate is 36% with an additional 25% having minimal microscopic disease. Median progression-free and overall survivals for patients receiving paclitaxel at 250 mg/m2 at a median potential follow-up of 22 months have not been reached for the cohort nor for the > or = 3-cm subgroup. This regimen should be evaluated in a prospective, randomized clinical trial.
A phase I/II study of continuous infusion suramin in patients with hormone-refractory prostate cancer: toxicity and response.
INTRODUCTION: Suramin is a synthetic polysulfonated naphthylurea which has been used for the treatment of African trypanosomiasis and onchocerciasis, but since the mid-1980s has received attention as a possible antiretroviral and antineoplastic agent. OBJECTIVE: This clinical trial of suramin was undertaken as a phase I/II study in patients with hormone-refractory prostate cancer, with the hypothesis that the intensity of therapy with suramin could be increased significantly if measures were undertaken to maintain the plasma concentrations of the drug under 300 microg/ml. METHODS: We report the clinical results of this trial, wherein patients were treated at three different targeted plasma suramin concentrations (275, 215 and 175 microg/ml) for varying periods of time (2, 4 or 8 weeks), with delivery of the drug by continuous intravenous infusion. RESULTS: The major toxicity observed in this trial was neurologic, consisting of a motor and sensory peripheral neuropathy that resulted in both paresis and paralysis of the limbs. Nearly all of this severe (CTEP grade III, IV) neurologic toxicity was observed in the patients treated at a plasma suramin concentration of 275 microg/ml for 4 or more weeks. A single patient treated at 215 microg/ml for 8 weeks developed moderate (CTEP grade III) proximal lower extremity weakness, and no patient treated at 175 microg/ml developed this toxicity. The second most common toxicity observed was infection of the central venous catheter. The overall response rate for all of the evaluable patients was 17% (13 of 75 patients). In addition, prostate-specific antigen (PSA)-defined responses were observed in six patients receiving therapy at 175 microg/ml, but these responses were confounded by cessation of therapy with flutamide during suramin treatment. CONCLUSIONS: In summary, although plasma suramin concentrations were maintained below 300 microg/ml, neurologic toxicity nonetheless occurred with high frequency in patients treated at 275 microg/ml for 4 or more weeks. Therapy at 215 and 175 microg/ml was in general well tolerated, but central venous catheter-related infection, as well as the inconvenience and expense of continuous infusional therapy, make this method of drug delivery impractical. Only moderate antitumor activity was observed during this trial, but it is possible that both continuation of flutamide and flutamide withdrawal during suramin therapy confounded the assessment of suramin's activity in hormone-refractory prostate cancer.
Borderline ovarian tumors.
Borderline tumor of the ovary (BOT) is an epithelial tumor with a low rate of growth and a low potential to invade or metastasize. This tumor often is associated with a significantly better prognosis than epithelial ovarian cancer. Most tumors are either serous or mucinous in histology and present as early stage lesions. However, stage III lesions with peritoneal implants are not uncommon. Patients with early stage lesions have an excellent prognosis. Patients with higher stage lesions have a worse prognosis. Long-term follow-up of patients with BOT is required since the tumor can recur up to 20 years after the initial diagnosis. Recently, investigators have begun to identify subsets of patients with a worse prognosis, such as patients with aneuploid tumors. Treatment for early stage lesions is surgical and conservative surgery can be accomplished successfully in younger patients who desire to maintain fertility. Treatment for later stage lesions has been approached in a variety of ways. All approaches initially begin with maximal cytoreductive surgery. Studies suggest that early stage disease should be managed with surgery alone. Conflicting results on the usefulness of adjuvant therapy for patients with later stage disease have been obtained. At this time, the usefulness of adjuvant therapy for advanced disease remains undetermined. Further understanding of the basis of the disease and analysis of specific higher risk subsets might identify patients in whom adjuvant therapy could be tested in the setting of controlled clinical trials.
The impact of disease severity on the informed consent process in clinical research.
PURPOSE: To assess the efficacy of informed consent in subjects differing in disease severity, ranging from those with immediately life-threatening disease to healthy volunteers. SUBJECTS AND METHODS: A total of 127 subjects, enrolled in four types of clinical research protocols, were tested. Subjects completed questionnaires before entry into the protocol, within 24 hours of signing the primary protocol's consent document, and 4 to 6 weeks after entry. RESULTS: Healthy volunteers retained the most information about risks and side effects, and severely ill Phase I subjects retained the least (P <0.0001). Phase I and II subjects had the best long-term retention of information about procedures, whereas Phase III subjects and healthy volunteers retained the least (P <0.001). Information about the scientific purpose and confidentiality of data were retained best by symptom-free, Phase III subjects (P <0.05). Phase I subjects entered the study primarily for treatment purposes, and the consent document was rated less useful by subjects with more advanced disease (P <0.05). CONCLUSIONS: Subjects with differing disease processes and illness severities focused on and retained different aspects of experimental protocols for dissimilar reasons. During the informed consent process, research staff should inquire of potential subjects' personal goals for participating in experimental protocols and develop means for ensuring subjects' understanding of the inherent risks and alternative interventions available.
Treatment approaches for metastatic cancer of the prostate based on recent molecular evidence.
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A phase I study of pentosan polysulfate sodium in patients with advanced malignancies.
BACKGROUND: Pentosan polysulfate (xylanopolyhydrogensulfate) is a semi-synthetic sulfated heparinoid polysaccharide which has been used as an anticoagulant for nearly thirty years in Europe. It antagonizes the binding of bFGF to cell surface receptors and has thus been evaluated for antitumor activity in several animal models and human tumor cell lines. In two angiogenic models pentosan has been shown to inhibit bFGF stimulation of angiogenesis. Previous clinical studies have determined the coagulation effects of pentosan to be the dose-limiting toxicity. PATIENTS AND METHODS: We conducted a phase I study designed to define the duration-limiting toxicity associated with progressive prolongation of a continuous intravenous infusion (three, five, and eight weeks). This study was not designed to escalate the dose of pentosan beyond that required to maintain the activated partial thromboplastin time (aPTT) between 1.8 and 2.2 times the baseline value. RESULTS: Thirteen patients with advanced stage metastatic cancer were enrolled (median age 50 years, range 34 to 61 years). Four patients were treated in cohort #1 (three weeks of infusional therapy), five patients were treated in cohort #2 (five weeks of therapy), and four patients in cohort #3 (eight weeks of therapy). All patients experienced a progressive prolongation of their aPTT and PT. Furthermore, all patients experienced at least grade I thrombocytopenia. Other complications were, in general, mild. One patient developed grade III liver abnormalities while receiving the eight-week infusion and another patient developed grade IV thrombocytopenia while receiving the same regimen. One patient with colon cancer had stable disease for 24 weeks, while the remaining 12 patients had no objective evidence of response. CONCLUSION: Pentosan was well tolerated when doses were adjusted for aPTT prolongations and a five-week cycle appeared to be the maximum tolerated duration of infusion (initially 4 mg/kg/day). One patient had stable disease, but there was no objective tumor response noted in the remaining 12 patients.