Hypoxic stress simultaneously stimulates vascular endothelial growth factor via hypoxia-inducible factor-1α and inhibits stromal cell-derived factor-1 in human endometrial stromal cells.

BACKGROUND: Hypoxia of the human endometrium is a physiologic event occurring during the perimenstrual period and the local stimulus for angiogenesis. The aim of this study was to investigate the effects of hypoxic stress on the regulation of vascular endothelial growth factor (VEGF) and stromal cell-derived factor-1 (SDF-1/CXCL12), and the potential role of hypoxia-inducible factor-1α (HIF-1α) in the endometrium. METHODS: Human endometrial stromal cells (ESCs, n= 22 samples) were studied in vitro. ESCs were cultured under hypoxic and normoxic conditions and treated with cobalt chloride (CoCl2; a hypoxia-mimicking agent) and/or echinomycin, a small-molecule inhibitor of HIF-1α activity. The mRNA levels and production of VEGF and SDF-1 were assessed by real-time PCR and ELISA, respectively. The HIF-1α protein levels were measured using western blot analysis. RESULTS: Hypoxia simultaneously induced the expression of mRNA and production of VEGF and attenuated the expression and production of SDF-1 from ESCs in a time-dependent manner. Similar changes were observed in the ESCs after stimulation with CoCl2 in a dose-dependent manner. CoCl2 significantly induced the expression of HIF-1α protein, and its highest expression was observed at 6 h. Echinomycin inhibited hypoxia-induced VEGF production without affecting the HIF-1α protein level and cell toxicity and had no effect on SDF-1 secretion (P < 0.01). CONCLUSIONS: Hypoxia simultaneously acts to increase VEGF via HIF-1α and to decrease SDF-1 in a HIF-1α-independent manner in ESCs. These results indicate a potential mechanism for the action of hypoxic conditions that could influence angiogenesis in the human endometrium.

A randomized phase II trial of echinomycin, trimetrexate, and cisplatin plus etoposide in patients with metastatic nonsmall cell lung carcinoma: an Eastern Cooperative Oncology Group Study (E1587).

BACKGROUND: Patients with metastatic nonsmall cell lung carcinoma (NSCLC) usually have a poor prognosis. A chemotherapy regimen containing cisplatin is commonly used for symptom palliation. Echinomycin is a potent bifunctional intercalator of double-strand DNA; trimetrexate is a new derivative of methotrexate and is active against methotrexate-resistant tumor cells in vitro. METHODS: The Eastern Cooperative Oncology Group conducted a randomized Phase II study. Eligible patients were assigned to receive echinomycin 1200 microg/m2 by intravenous (i.v.) infusion over 30-60 minutes once a week for 4 weeks, repeated every 6 weeks; trimetrexate 12 mg/m2 i.v. bolus on Days 1-5 every 3 weeks, or 8 mg/m2 i.v. bolus on Days 1-5 for patients who had prior radiation to greater than 30% of their bone marrow; or cisplatin 60 mg/m2 i.v. on Day 1 and etoposide 120 mg/m2 i.v. on Days 1-3 every 4 weeks. Patients were evaluated before each cycle for tumor response, toxicity, and quality-of-life measurements. RESULTS: One hundred thirty-six patients were entered on the study, and 118 were evaluable for toxicity and response. The response rates were 16%, 5%, and 5% in patients treated with cisplatin and etoposide, echinomycin, and trimetrexate, respectively. There were no complete responses. The median survival was 37.9, 24.3, and 28.0 weeks for patients who received cisplatin and etoposide, echinomycin, and trimetrexate, respectively. Although cisplatin and etoposide appeared to give better therapeutic results, the response rate or survival did not reach statistical significance. This may have been due to inadequate sample size. Neither did quality-of-life measurement show any significant differences among treatments. CONCLUSIONS: Echinomycin and trimetrexate had minimal antitumor activity in patients with metastatic NSCLC: Response rate and survival remained poor in all three treatment arms. Patients should be encouraged to participate in clinical trials so that more effective therapy can be identified.

A phase II clinical trial of echinomycin in metastatic soft tissue sarcoma. An Illinois Cancer Center Study.

Echinomycin, a cyclic peptide in the family of quinoxaline antibiotics, was evaluated in patient with metastatic, soft tissue sarcoma not previously treated for metastatic disease. The starting dose of echinomycin was 1,200 mcg/m2 administered intravenously, once weekly x 4, followed by a two-week break. The protocol design called for dose escalation on subsequent cycles of therapy, but because of significant toxicity, dose escalation occurred in only 5 of 25 treatment cycles. Severe nausea and vomiting was the most common toxicity. No clinical responses were observed in the 12 evaluable patients. Echinomycin at this dose and schedule is inactive in metastatic soft tissue sarcoma.

Phase II trial of echinomycin in patients with advanced or recurrent colorectal cancer.

Echinomycin is a novel bifunctional intercalating agent derived from Streptomyces echinatus. A phase II clinical trial of echinomycin in patients with advanced, measurable colorectal cancer was initiated to determine the efficacy and toxicities of this agent. Echinomycin, 1.5 mg/m2, was given initially as a 30- to 60-min infusion every 4 weeks. After 4 episodes of anaphylaxis had occurred among the first 14 patients, the schedule was changed to a 24-h infusion, and an additional 16 patients were treated on this schedule. Treatment was given every 3 weeks. A total of 30 patients were eligible and evaluable; there were 3 (10%; 90% confidence interval, 3%-23%) clinical responses lasting 3, 3+, and 12 months, respectively. The most serious toxicity encountered was anaphylaxis, which occurred in 5 patients, although with no serious sequelae. A premedication regimen with dexamethasone, diphenhydramine, and cimetidine and a change of the duration of the infusion to 24 h reduced the incidence of this complication. Grade 2-3 vomiting occurred among earlier patients treated; however, with the 24-h schedule this toxicity was substantially reduced. The sole important case of hematologic toxicity was a single patient with grade 3 thrombocytopenia. Echinomycin employed in this dose and schedule had modest activity against colorectal cancer, comparable with that observed with 5-fluorouracil. Further studies in patients with gastrointestinal malignancies using a 24-h infusion with a dexamethasone premedication regimen similar to that employed prior to administration of taxol may be warranted.

Phase II study of echinomycin in the treatment of renal cell carcinoma ECOG study E2885.

Seventeen patients were treated with echinomycin for metastatic renal cell carcinoma. Echinomycin is a bifunctional DNA intercalating agent with broad preclinical antitumor activity. It was given at 1200 mg/m2 by intravenous infusion over 30-60 min weekly for 4 weeks. The treatment was repeated every 6 weeks. There were no responses observed in the study. No life threatening or lethal toxicity was documented in 13 eligible patients. The median survival of these patients was 13.7 months. We conclude that echinomycin is not active against metastatic renal cell carcinoma at the dose and schedule tested.

Phase II trial of echinomycin for the treatment of advanced renal cell carcinoma. A Southwest Oncology Group study.

Forty-nine patients with metastatic or recurrent renal cell carcinoma were treated on a phase II trial of Echinomycin. Treatment consisted of Echinomycin 1.25 mg/m2 intravenously every 28 days. Among the 47 evaluable patients there were no complete responses and only one partial response for an overall response rate of 2% (95% confidence interval, 0-11%). Eighteen patients (38%) experienced toxicity of grade 3 or worse. The most common toxicities were nausea and vomiting. The results of this study indicate that Echinomycin is not sufficiently active to warrant further trials for the treatment of renal cell carcinoma.

Phase II evaluation of echinomycin (NSC-526417) in patients with central nervous system malignancies. A Southwest Oncology Group study.

The objective of this trial was to determine the efficacy of echinomycin (1.2 mg/m2) administered on a weekly times four schedule in the treatment of patients with recurrent or progressive central nervous malignancies despite adequate radiotherapy. Thirty-five patients were registered on study. The majority of patients (20) had glioblastoma multiforme. Ten had anaplastic astrocytoma. Eight patients had received prior nitrosoureas. SWOG performance status was 1 in 11 patients and 2 in 22. The median age was 51 years (25-75 years). One patient had a partial remission (3%:95% confidence interval: 1%-16%). Twenty two patients had progressive disease. The median survival was 5.9 months. Toxicity was primarily gastrointestinal with nausea and vomiting in 13 patients and nausea only in 11 patients. Hepatotoxicity occurred in 10 patients. Echinomycin given at this dose and schedule is not effective in treating patients with recurrent or progressive glioblastoma multiforme or anaplastic astrocytomas.

Echinomycin (NSC 526417) in recurrent and metastatic squamous cell carcinoma of the cervix. A phase II trial of the Gynecologic Oncology Group (GOG).

Nineteen evaluable patients with recurrent or metastatic squamous cell carcinoma of the uterine cervix were treated with 1,500 micrograms/m2 of echinomycin every 4 weeks. No patient had received prior chemotherapy. There was one partial response (5% response, 95% confidence interval for response of 0% to 26%). The major toxicity was nausea and vomiting which was moderate to severe in six patients. Myelosuppression was not observed. Echinomycin, in this dose and schedule displays no major activity in chemotherapy-naive patients with advanced squamous-cell carcinoma of the cervix.

Phase II study of echinomycin in patients with advanced breast cancer: a report of Cancer and Leukemia Group B protocol 8641.

Twenty-five women with advanced histologically documented stage IV recurrent or inoperable breast cancer were enrolled on a phase II study of echinomycin administered at a dose of 1.2 mg/m2 intravenously over 30 minutes weekly for 4 weeks followed by a two week rest period. Seventy-six percent of patients had visceral dominant disease at study entry and all patients had previously received chemotherapy. One of 21 eligible patients had a partial response lasting 147 days. The median survival for this group of patients was 5.9 months and the median time to treatment failure was 1.7 months. Nausea and vomiting was the primary toxic effect and was severe or life-threatening in 43% of patients. Transient elevation of liver enzymes occurred in 30% of patients. Bone marrow suppression was not significant. Echinomycin as employed in this study did not demonstrate significant antitumor activity in previously treated patients with advanced breast cancer.

Phase II trial of echinomycin in advanced soft tissue sarcomas. A Southwest Oncology Group study.

Thirty-four patients with advanced soft tissue sarcomas were entered in a phase II trial of echinomycin. Patients received 1.2 mg/m2 intravenously (i.v.) weekly times four followed by a two week rest period. There were no objective responses. Dose limiting toxicity was gastrointestinal. Echinomycin given on this weekly schedule is inactive in treating previously treated patients with advanced soft tissue sarcomas.

Echinomycin (NSC 526417) in squamous-cell carcinoma of the cervix. A phase II trial of the Gynecologic Oncology Group.

Twenty-eight evaluable patients with advanced or recurrent squamous-cell carcinoma of the cervix were treated with 1,500 micrograms/m2 of echinomycin every 4 weeks. All patients had prior chemotherapy. Two patients had partial responses (7% response, 95% confidence interval for response of 1 to 24%). The major toxicity was nausea and vomiting. Myelosuppression and other toxicity were modest. Echinomycin, at this dose and schedule, displays minimal activity in patients with squamous-cell carcinoma of the cervix who have had prior chemotherapy.

Phase I study of echinomycin.

Echinomycin was administered to patients with advanced carcinoma in escalating doses ranging from 60 to 1500 micrograms/m2 given weekly by 15-minute iv infusions for four doses, with a subsequent 2-week rest period. Dose-limiting nausea, vomiting, and anorexia associated with varying degrees of renal and hepatic dysfunction proved dose-limiting at the 1500-micrograms/m2 level. Thrombocytopenia was noted in 15% of patients receiving greater than or equal to 700 micrograms/m2 and was severe in 11% without an evident dose-response relationship. Leukopenia was rare and mild when encountered. Allergic reactions were observed. Phase II trials are feasible using a dose schedule of 1200 micrograms/m2/week X 4 weeks.

Phase I study of echinomycin administered on an intermittent bolus schedule.

We have conducted a phase I study of the cyclic peptide echinomycin (Quinomycin A) on a schedule of administration of once every 4 weeks. Ten dose levels between 20 and 1800 micrograms/m2 were studied. Acute gastrointestinal toxicity, thrombocytopenia, and transient elevations of serum transaminases occurred at doses of greater than or equal to 1000 micrograms/m2. Gastrointestinal toxicity was severe and dose-limiting in several patients at doses of 1800 micrograms/m2. Thrombocytopenia was erratic, but generally increased with drug doses. Platelet count nadirs occurred 5-10 days after administration. Hepatic toxicity was reflected in transient elevations of serum transaminases without hyperbilirubinemia. Three patients experienced apparent anaphylactic reactions to doses of 1500 micrograms/m2. The maximum tolerated single dose of echinomycin was 1800 micrograms/m2. A starting phase II dose of 1500 micrograms/m2 is recommended.