The systemic delivery of an oncolytic adenovirus expressing decorin inhibits bone metastasis in a mouse model of human prostate cancer.

In an effort to develop a new therapy for prostate cancer (PCa) bone metastases, we have created Ad.dcn, a recombinant oncolytic adenovirus carrying the human decorin gene. Infection of PC-3 and DU-145, the human prostate tumor cells, with Ad.dcn or a non-replicating adenovirus Ad(E1-).dcn resulted in decorin expression; Ad.dcn produced high viral titers and cytotoxicity in human prostate tumor cells. Adenoviral-mediated decorin expression inhibited Met, the Wnt/ß-catenin signaling axis, vascular endothelial growth factor A, reduced mitochondrial DNA levels and inhibited tumor cell migration. To examine the antitumor response of Ad.dcn, PC-3-luc cells were inoculated in the left heart ventricle to establish bone metastases in nude mice. Ad.dcn, in conjunction with control replicating and non-replicating vectors were injected via tail vein. The real-time monitoring of mice, once a week, by bioluminescence imaging and X-ray radiography showed that Ad.dcn produced significant inhibition of skeletal metastases. Analyses of the mice at the terminal time point indicated a significant reduction in the tumor burden, osteoclast number, serum tartrate-resistant acid phosphatase 5b levels, osteocalcin levels, hypercalcemia, inhibition of cancer cachexia and an increase in the animal survival. Based on these studies, we believe that Ad.dcn can be developed as a potential new therapy for PCa bone metastasis.

A randomized, phase II study of pazopanib in castrate-sensitive prostate cancer: a University of Chicago Phase II Consortium/Department of Defense Prostate Cancer Clinical Trials Consortium study.

BACKGROUND: Intermittent androgen suppression (IAS) is an increasingly popular treatment option for castrate-sensitive prostate cancer. On the basis of previous data with anti-angiogenic strategies, we hypothesized that pan-inhibition of the vascular endothelial growth factor receptor using pazopanib during the IAS off period would result in prolonged time to PSA failure. METHODS: Men with biochemically recurrent prostate cancer, whose PSA was <0.5 ng ml(-1) after 6 months of androgen deprivation therapy were randomized to pazopanib 800 mg daily or observation. The planned primary outcome was time to PSA progression >4.0 ng ml(-1). RESULTS: Thirty-seven patients were randomized. Of 18 patients randomized to pazopanib, at the time of study closure, 4 had progressive disease, 1 remained on treatment and 13 (72%) electively disenrolled, the most common reason being patient request due to grade 1/2 toxicity (8 patients). Two additional patients were removed from treatment due to adverse events. Of 19 patients randomized to observation, at the time of study closure, 4 had progressive disease, 7 remained under protocol-defined observation and 8 (42%) had disenrolled, most commonly due to non-compliance with protocol visits (3 patients). Because of high dropout rates in both arms, the study was halted. CONCLUSIONS: IAS is a treatment approach that may facilitate investigation of novel agents in the hormone-sensitive state. This trial attempted to investigate the role of antiangiogenic therapy in this setting, but encountered several barriers, including toxicities and patient non-compliance, which can make implementation of such a study difficult. Future investigative efforts in this arena should carefully consider drug toxicity and employ a design that maximizes patient convenience to reduce the dropout rate.

Phase II trial of cisplatin, etoposide, and 5-fluorouracil in advanced non-small-cell lung cancer: an Eastern Cooperative Oncology Group Study (PB586).

Advanced non-small-cell lung cancer (NSCLC) remains an incurable disease despite significant progress in chemotherapy. We conducted a phase II clinical trial to investigate the efficacy and toxicity of a cisplatin, etoposide, and 5-fluorouracil (5-FU) combination in advanced metastatic and/or recurrent NSCLC. Forty patients with advanced, recurrent, or metastatic, measurable NSCLC were treated with cisplatin, 60 mg/m2 intravenously (i.v.) on day 1; etoposide, 120 mg/m2/day i.v. on days 1, 2, and 3; and 5-FU. 1,000 mg/m2/day i.v. continuous infusion on days 1 through 5. Treatment was administered in 4-week cycles. Thirty patients had distant metastases and were previously untreated, and 10 patients had recurrent disease after prior treatment with either surgery (1 patient), radiation therapy (5 patients), or both treatments (4 patients). Twenty-nine patients were evaluable for response. Seven (24%) patients achieved a partial remission (PR), 18 (62%) had stable disease (SD), and 8 (14%) had progressive disease (PD). Overall median survival was 7.9 months (range, 0.4-27.4 months). Patients who achieved a PR had a median survival of 23.5 months (9.3-27.4 months). In contrast, patients with SD had a median survival of 9.9 months (2.5-25.3 months), and patients with PD had a median survival of 2.1 months (1-9.3 months). Median duration of response of 27.1 weeks (4.9-76.5 weeks) for patients with PR, and time to progression was 13.4 weeks (3.7-54.5 weeks) for patients with SD. Toxicity was primarily hematologic and gastrointestinal, and there were three deaths due to infection. The combination of cisplatin, 5-FU, and etoposide as administered in this study appears to have considerable toxicity and does not appear to be superior to other cisplatin-containing regimens used for the treatment of advanced NSCLC.

Assessment of coagulation system activation using spot urine measurements.

Coagulation system activation is most commonly assessed by measuring levels of one or more proteins in peripheral blood. Because faulty blood-drawing can cause activation of the coagulation system, artifactual elevations of such markers have been reported. We have therefore investigated the possibility of using randomly collected ('spot') urine samples as a non-invasive means of assessing the state of coagulation system activation. Using a commercially available enzyme-linked immunosorbent assay kit designed to measure plasma levels of fragment 1 + 2, we found immunoreactive fragment 2 in healthy control subjects, and significantly increased levels in diabetic and non-diabetic pregnant subjects, and patients with venous thromboembolism, prostate cancer, and diabetes. Measurements of excretion of immunoreactive fragment 2 are worth further study as an adjunct or alternative to plasma-based assays designed to detect or quantify coagulation system activation.

A case of therapy-related extramedullary acute promyelocytic leukemia.

We report a patient with extramedullary acute promyelocytic leukemia (APL) occurring after radiation therapy for carcinoma of the prostate. To the authors' knowledge, this patient represents the first case of cytogenetically and fluorescence in situ hybridization (FISH) confirmed therapy-related extramedullary APL. In contrast to the majority of previously reported t-APL, this case underwent a very unfavorable course.

A phase II study of continuous infusion 5-fluorouracil in advanced hormone refractory prostate cancer. An Illinois Cancer Center Study.

BACKGROUND: 5-Fluorouracil (5-FU) has been previously associated with therapeutic benefit in hormone refractory prostate cancer. However, no previous study has administered 5-FU as a prolonged continuous infusion, which may be the optimal schedule for this cell-cycle specific agent. METHODS: Therefore, 25 patients were treated with 5-FU administered as a continuous intravenous infusion at a dose of 1000 mg/m2/day for 5 days every 28 days. Eligibility required disease defined by bidimensionally measurable lesions or evaluable lesions on bone scan or radiograph with elevated serum levels of prostate-specific antigen (PSA), no severe cytopenias, and an Eastern Cooperative Oncology Group performance status less than 3. Prior chemotherapy was not allowed. Dose modifications were specified for mucositis and hematologic toxicity. RESULTS: Eighteen of 22 patients were evaluable for response and toxicity, whereas 4 were evaluable for toxicity alone. Toxicity was significant using this dose and schedule and included episodes of sudden death (one patient), paroxysmal supraventricular tachycardia (one patient), and congestive heart failure (one patient). Other Grade 3 toxicities included stomatitis (two patients) and diarrhea (one patient). Significant myelosuppression did not occur. Objective responses were not observed, but 12 patients experienced stable disease with a median duration of 4 months. CONCLUSIONS: Infusional 5-FU can not be recommended for the treatment of advanced hormone refractory prostate cancer.

In vivo and in vitro approaches to study metastasis in human prostatic cancer.

Prostate cancer is the most common malignancy in American males and is second only to lung cancer as a cause of death in the United States. Clinically, radical prostatectomy offers a patient with locally contained disease an excellent chance for cure. For patients with metastatic disease, the current therapies are merely palliative. Understanding the biology of prostate cancer metastasis should facilitate the development of novel and effective therapeutic modalities. Crucial to this objective is the availability of human tumor systems in which the biology of metastasis can be studied. The present chapter will briefly assess various in vivo and in vitro approaches to study metastasis in human prostate cancer. Utilization of athymic nude mice has played an important role in maintaining human prostatic cancer cells as xenografts and has provided an opportunity to establish site-specific subpopulations of the parental cell lines for further characterization and investigation. At present, a few established cell lines have been useful for this purpose. Fresh tumor specimens, unfortunately, have shown limited ability to grow in nude mice. The recent development of novel approaches to permit the maintenance of freshly harvested prostate cancers has been encouraging. The use of reconstituted basement membrane (Matrigel) for co-injection with cancer cells into the subcutaneous tissues has supported growth of biologically indolent tumors. Another approach is to administer tumor cells orthotopically into the prostate of recipient nude mice. Bone marrow metastases in nude mice have been rare in the past. Recently, three approaches have been shown to be successful in accomplishing bony metastasis with PC-3 cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Use of clonidine to treat hot flashes secondary to leuprolide or goserelin.

OBJECTIVE: To determine the effects of clonidine, a centrally acting adrenergic agonist, in abating symptoms of hot flashes in men receiving either leuprolide or goserelin for prostate cancer. DESIGN: Patients were administered transdermal or oral clonidine 0.1-0.2 mg/d. Dosages were increased in increments of 0.1-0.3 mg/d every two to four weeks if symptoms persisted or until adverse effects developed. SETTING: Medical oncology clinic at the University of Illinois and the hypertension clinic at the Veterans Affairs West Side Medical Center. PARTICIPANTS: Consenting male patients were eligible for the study if they were receiving leuprolide or goserelin for prostate cancer and were experiencing hot flashes. Exclusion criteria included diastolic blood pressure of 75 mm Hg or below or a history of adverse reactions to clonidine. MAIN OUTCOME MEASURES: Effectiveness of clonidine was determined by questioning patients about frequency, severity, and duration of hot flashes at baseline and at two- to four-week intervals. RESULTS: All four patients receiving clonidine experienced a partial response within two weeks of starting treatment. No dose-dependent response was observed. Adverse effects were noted in one patient but did not result in discontinuation. CONCLUSIONS: Our results document the first report of the use of clonidine to treat hot flashes secondary to leuprolide or goserelin therapy. Symptomatic improvement was noted in all four patients. Further evaluation of clonidine as well as other centrally acting adrenergic agonists is needed.

Effect of etidronate disodium on the development of bone lesions in an animal model of bone metastasis using the human prostate cancer cell line PC-3.

We have established an animal model of bone metastasis using the PC-3 human prostate tumor cell line. In order to assess whether inhibition of bone resorption would prevent the development of bone metastasis, the diphosphonate etidronate (EHDP) was administered to 20 mice at a dose of 30 mg/kg subcutaneously daily starting 2 days prior to injection of tumor cells. Control mice received daily injections of the saline vehicle. In the EHDP-treated mice, there was no significant reduction in the incidence of bone metastasis, the size of the lesions, or the number of bone lesions per mouse. Approximately 50% of the mice developed bone metastasis, which was similar to the control group and similar to what was observed in earlier studies with this animal model. Histomorphometric analysis of bones showed marked inhibition of mineralization in EHDP-treated mice, thus indicating biological effect on the bone. Therefore, the use of EHDP in biologically effective doses failed to reduce the incidence, size, or number of bone metastases in this animal model.

Tumor resection and antibodies to parathyroid hormone-related protein cause similar changes on bone histomorphometry in hypercalcemia of cancer.

Bone resorption is increased in both humoral hypercalcemia of malignancy (HHM) and primary hyperparathyroidism. On the other hand, bone formation parameters are increased in primary hyperparathyroidism and decreased in HHM. Recently, a PTH-related protein (PTHrP) has been shown to be responsible for the hypercalcemia in the syndrome of HHM. In the present study we evaluated the effects of a neutralizing antiserum to PTHrP on bone histomorphometric parameters in hypercalcemic athymic mice bearing a human squamous cell lung cancer. These effects were compared to those of tumor resection. Similar to the effects of tumor resection, the antiserum to PTHrP resulted in a decrease in serum Ca levels, a decrease in bone resorption, and an increase in bone formation parameters. The studies, therefore, indicate that PTHrP is the major factor responsible for all of the features, including the decreased bone formation seen in HHM.

Effects of hypercalcemia-producing tumor extract and parathyroid hormone on osteoclast ultrastructure.

Hypercalcemia is a frequent complication of cancer. Recently, parathyroid hormone-related protein has been isolated from tumors associated with this syndrome. In the present study, the effects of tumor-derived hypercalcemic factor and bovine parathyroid hormone (PTH) on bone were compared in an organ culture system using calvarial bones from newborn mice. Mouse calvaria were incubated for 72 h with control medium or media containing 0.15 mg/m tumor extract (TE) or 2 x 10(-9) M PTH. Bone resorption, as assessed by the amount of calcium released into the medium and the number of osteoclasts counted on light microscopy, was increased by both PTH and TE. On electron microscopy, areas for cytoplasm, ruffled border and clear zone were statistically increased in PTH- and TE-treated calvaria as compared to control. These values were not significantly different between PTH- and TE-treated calvaria. The study therefore demonstrates that the ultrastructural changes in osteoclasts induced by the hypercalcemia-producing TE are similar to those induced by PTH.

Phase II trial of spirogermanium in advanced non-small cell lung cancer. An Illinois Cancer Council Study.

A phase II trial of spirogermanium was conducted in advanced previously untreated non-small cell lung cancer patients. The drug was given by intravenous infusion 3 times per week for 2 weeks, twice per week for the next 2 weeks, and then weekly. Starting dose was 125 mg/m2, and dose escalation of 25 mg/m2 per week was required in the absence of toxicity to a maximum dose of 200 mg/m2 per infusion. Fifteen eligible patients were treated, and no objective responses were seen. Primary toxicity was neurologic and reversible after withdrawal of the drug. We conclude that spirogermanium is not active against non-small cell lung cancer in the dosage used in this study.

Phase II trial of fludarabine phosphate in advanced renal cell carcinoma: an Illinois Cancer Council Study.

Fludarabine Phosphate (FP), the 2-fluoro, 5'phosphate derivative of adenosine arabinoside (ara-A), was studied in 18 patients with advanced renal cell carcinoma. These patients had measurable disease and had not received chemotherapy. FP was administered at a loading dose of 20 mg/m2 followed by a 48-hour infusion at 30 mg/m2/day given every 21 days. There were no complete or partial responses seen. Toxicity was mainly hematologic, with leukopenia most commonly observed. FP given in this manner had no activity in advanced renal cell carcinoma.

Effect of hypercalcemia-producing tumor on 1,25(OH)2D3 biosynthesis in athymic mice.

Serum 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] levels are low in patients with malignancy-associated hypercalcemia (MAH), whereas murine models of MAH have high circulating 1,25(OH)2D3. To determine the effects of a hypercalcemia-producing tumor on circulating 1,25(OH)2D3, in vitro 25-hydroxyvitamin D1-hydroxylase (1OHase) activity was measured in kidneys from BALB/c athymic mice implanted with a hypercalcemia-producing human lung tumor. Twelve days of low-phosphorus diet (LPD) in control animals lowered serum phosphorus to levels found in tumor-bearing mice fed normal phosphorus diet (NPD; 4.1 +/- 0.3 vs. 4.4 +/- 0.7 mg/dl, P = NS) and increased 1OHase activity (1.6 +/- 0.2 vs. 3.9 +/- 0.7 pmol.mg protein-1.5 min-1, NPD vs. LPD, P less than 0.05). 1OHase activity was greater in tumor-bearing animals fed NPD compared with control animals fed LPD (8.4 +/- 0.6 vs. 3.9 +/- 0.7 pmol.mg protein-1.5 min-1, P less than 0.01). High-phosphorus intake suppressed 1OHase activity in both control and tumor-bearing animals. Seven days of parathyroid hormone infusion in control animals fed NPD raised serum calcium (9.4 +/- 0.2 vs. 13.3 +/- 1.6 mg/dl, P less than 0.05) and suppressed 1OHase activity (0.25 +/- 0.02 vs. 0.02 +/- 0.002 pmol.mg protein-1.5 min-1, P less than 0.001). The inverse relationship of serum phosphorus and 1OHase activity was much steeper in the tumor-bearing animals, with greater enzyme activity at comparable levels of serum phosphorus. The present study indicates that 1) factors produced by the tumor stimulate 1OHase activity, and 2) hypophosphatemia is required for expression of enhanced enzyme activity.

Patterns of metastasis by the human prostate cancer cell line PC-3 in athymic nude mice.

Cells from the PC-3 human prostate cancer cell line were evaluated in athymic nude mice in order to determine the influence of size of the primary tumor and site inoculation on the incidence and pattern of metastasis. At autopsy, all organs, including the skeleton, were evaluated for metastasis. Subcutaneous injections resulted in metastases to the draining axillary lymph node and lungs (56% and 13%, respectively), and were correlated with size of the primary tumor. Tail vein injection resulted in a high incidence of lung metastasis, while injection into the peritoneal space, spleen, and seminal vesicles resulted in intraabdominal tumor growth, liver metastasis, and large tumors within the seminal vesicles, respectively. Skeletal metastases were not observed in any of the animals studied. We conclude that injection of PC-3 cells into various sites results in different patterns of metastasis, but may not constitute an entirely suitable animal model of human prostate cancer due to the lack of metastasis to the skeleton.

Antibodies to parathyroid hormone-related protein lower serum calcium in athymic mouse models of malignancy-associated hypercalcemia due to human tumors.

A parathyroid hormone-related protein (PTHrP) has recently been isolated from tumors associated with hypercalcemia. In the present study, we tested the effects of neutralizing antisera to the PTHrP on serum calcium and urine cAMP in two animal models of malignancy-associated hypercalcemia. The animal models consisted of (a) a human squamous cell lung cancer and (b) a human laryngeal cancer, both serially carried in athymic mice. The antisera specifically reduced the elevated serum calcium and urinary cAMP levels in the tumor-bearing animals. We conclude that PTHrP plays a major role in the pathogenesis of malignancy-associated hypercalcemia.

Effects of cisplatin on parathyroid hormone- and human lung tumor-induced bone resorption.

We have previously shown that dichlorodiamine platinum (DDP), or cisplatin, a cancer chemotherapeutic agent, is effective in the treatment of malignancy-associated hypercalcemia. In the present studies, we evaluated its effects on bovine parathyroid hormone (PTH)- or tumor-induced bone resorption in vitro in the neonatal mouse calvarial bone resorption assay. PTH alone or tumor extract (TE) of a human squamous cell lung cancer alone caused a significant increase in the bone resorption and in the number of osteoclasts in the calvaria. The addition of 3 and 10 micrograms/ml DDP inhibited the PTH- or TE-induced bone resorption. Lower doses of 1 and 2 micrograms/ml DDP, although not effective in inhibiting the PTH-induced bone resorption, were effective in lowering the TE-induced bone resorption. The number of osteoclasts was also reduced by DDP treatment. We therefore conclude that DDP is effective in the treatment of malignancy-associated hypercalcemia by virtue of its inhibitory effects on osteoclast numbers and on bone resorption.

Increased renal calcium reabsorption in an animal model of hypercalcemia of human malignancy.

The present studies examined renal calcium (Ca) clearance in an animal model of malignancy-associated humoral hypercalcemia (MAHH) (a human squamous cell lung carcinoma carried in athymic mice). Three groups of animals--controls, normocalcemic tumor-bearing animals and hypercalcemic tumor-bearing animals--were studied in the basal state and during Ca infusion. Baseline Ca clearance was slightly but significantly elevated in the tumor-bearing hypercalcemic animals compared with the other two groups of animals. This clearance value was, however, inappropriately low for the serum Ca value. In the control and in the normocalcemic tumor-bearing animals, Ca clearance increased markedly during Ca infusion. This increase in renal Ca clearance was markedly blunted in the hypercalcemic animals compared with both the controls and the normocalcemic tumor-bearing animals. We conclude that increased renal Ca resorption contributes significantly to the pathogenesis of hypercalcemia of malignancy.