Phase I study of paclitaxel and day 1/day 8 gemcitabine in patients with solid malignancies.

A phase I study was designed to evaluate the toxicity of escalating doses of gemcitabine along with fixed-dose paclitaxel in patients heavily pretreated with chemotherapy or radiotherapy. All patients had no prior therapy with the study drugs and possessed both adequate performance and end organ function. Eighteen patients were entered in the study. Characteristics included a median age of 66 years (range, 41 to 77) and stage IV disease in all patients; there were six patients with colon cancer, two with bladder cancer, three with non-small-cell lung cancer, two with esophageal cancer, three with pancreatic cancer, and two with cancer of unknown primary. Paclitaxel (150 mg/m2 over 3 hours) was given on day 1 and gemcitabine (800, 900, and 1,000 mg/m2 over 15 minutes) was given in three separate dose-escalating cohorts (1-3) on days 1 and 8. The treatment cycled every 21 days. The dose-limiting toxicity (DLT) proved to be neutropenia. All nonhematologic toxicities were mild and included gastrointestinal (nausea, vomiting, and diarrhea), dermatologic (rash), and neurologic (paresthesias) disturbances along with transient elevations of liver function tests. The combination of gemcitabine and paclitaxel seems to be well tolerated, and the recommended starting dose for a phase II study, in pretreated patients using a day 1/day 8 treatment schedule, should be 900 mg/m2 for gemcitabine (days 1 and 8) along with 150 mg/m2 for paclitaxel (day 1).

Suppository delivery of 5-fluorouracil in rectal cancer.

BACKGROUND: Preoperative radiotherapy with concomitant intravenous 5-fluorouracil (5-FU-i.v.) is effective in shrinking locally advanced rectal cancers and facilitating subsequent surgery. Topical 5-FU application may enhance its radiosensitizing and cytotoxic effects. Suppository and intravenous 5-FU administration were compared with respect to myelo-suppression and tissue concentrations. METHODS: Rats received 120 mg/kg 5-FU-i.v. or via suppository (5-FU-S). White blood cell count, serum albumin, alkaline phosphatase, creatinine, and aspartate aminotransferase (AST) were determined before and serially after 5-FU administration. In a separate experiment, rats received 5-FU-S or 5-FU-i.v. as already described. Portal and systemic blood, rectal, iliac lymph node, liver, and lung tissue were harvested for high-performance liquid chromatography determination of 5-FU concentrations 30 min, 1, 3, 6, and 12 h after drug administration. RESULTS: No toxicity was observed in 5-FU-S animals, whereas 63% of 5-FU-IV animals had diarrhea. Weight loss and myelosuppression occurred only in 5-FU-i.v. animals. Rectal drug concentrations were significantly higher in the 5-FU-S animals compared with 5-FU-i.v. animals, 0.5-6 h after drug administration. Blood, liver, and lung 5-FU concentrations with 5-FU-S were comparable to those with 5-FU-i.v. CONCLUSIONS: 5-FU suppositories are associated with fewer systemic side effects and higher rectal 5-FU concentrations than with 5-FU-i.v. administration.

Suramin interference with transforming growth factor-beta inhibition of human renal cell carcinoma in culture.

Suramin is a polyanionic compound used clinically for the treatment of trypanosomiasis, which is known to inhibit the action of many protein factors in vitro. Transforming growth factor-beta (TGF-beta) is a multifunctional regulatory protein which inhibits the growth of renal cell carcinoma in culture. While suramin at 50-500 micrograms/ml had no significant effect on the growth of renal cell carcinoma in culture in our experiments, it did partially reverse the growth inhibition induced by TGF-beta in the two cell lines tested. This effect apparently is caused by suramin's direct interference with 125I-labeled TGF-beta's ability to bind to the cell, and not by any effect of suramin on the TGF-beta receptor. Furthermore, suramin dissociates TGF-beta bound to the cell with a t1/2 of less than 30 min. These results are consistent with those previously reported regarding suramin's interaction with other protein growth factors, and suggest that suramin may interact with the TGF-beta protein itself to inactivate it.

Suramin in advanced platinum-resistant ovarian cancer.

10 patients with ovarian cancer, whose disease had progressed while receiving platinum-based therapy, were entered onto a phase II clinical trial of the antiproliferative agent suramin. Suramin was administered in a fashion that is associated with durable objective disease response in patients with hormonally resistant metastatic prostate cancer. No individual had an objective response to therapy in this study, but 3 of 9 evaluable patients (33%) experienced disease stabilisation and subjective clinical improvement for periods ranging from 2 to 5 months. Disease stabilisation was associated with prolonged periods of comparatively high plasma levels of drug, which appeared to be determined primarily by reduced drug clearance. We conclude that suramin has potential activity in platinum-resistant ovarian cancer, and we have initiated a second clinical trial using pharmacological information derived from this study.

Use of suramin in treatment of prostatic carcinoma refractory to conventional hormonal manipulation.

Suramin and related compounds, in view of their growth factor and enzyme binding properties, represent in many respects a novel approach to the treatment of cancer. Although in this preliminary analysis of suramin use in the treatment of metastatic prostate cancer, the objective response rate does not appear impressive, much work still needs to be done to optimize suramin's administration to patients and to elucidate its various postulated mechanisms of action. The development of related compounds with more specific enzyme and growth factor antagonist properties is under way.

Characteristics of cell lines established from human gastric carcinoma.

We report the establishment and characterization of four continuous cell lines derived from human primary and metastatic gastric carcinomas, and we compare their properties with a panel of colorectal carcinoma cell lines previously established and reported by us. Our success rate in culturing gastric carcinomas was relatively low, especially from primary tumors, compared to colorectal carcinoma. These observations may reflect the relatively modest number of gastric carcinoma cell lines established (mainly from Japan), compared to the abundance of colorectal carcinoma lines established worldwide. All four gastric lines expressed the surface glycoproteins carcinoembryonic antigen and TAG-72 and three lines expressed CA 19-9. Two of the lines expressed aromatic amino acid decarboxylase but lacked other markers for neuroendocrine differentiation. All four lines were positive for vasoactive intestinal peptide receptors but lacked gastrin receptors. In addition, two lines expressed receptors for muscarinic/cholinergic receptors but not beta-adrenergic receptors. Cytogenetic evidence for gene amplification was present in the cell lines. All four lines contained varying numbers of double-minute chromosomes. One line, SNU-16, was amplified for the c-myc proto-oncogene and contained four homogeneously staining regions. While c-myc and c-erb-B-2 RNA were expressed by all lines, there was no evidence of amplification or overexpression of several other proto-oncogenes and growth factors. The multiple properties we have described in our gastric carcinoma cell lines are remarkably similar to those found in the panel of colorectal carcinoma cell lines. These properties include morphology, growth characteristics, expression of surface glycoproteins, partial expression of neuroendocrine cell markers, frequent chromosomal evidence of gene amplification, and occasional amplification of the c-myc proto-oncogene. Our four well characterized cell lines should provide useful additions to the modest number currently available for in vitro studies of gastric carcinoma.

Patterns of proto-oncogene expression in human glioma cell lines.

Previously reported studies have suggested that variations in the pattern of proto-oncogene expression within a specific tumor type may denote an underlying difference in the biology and clinical behavior of those tumors. To more sensitively characterize malignant tumors of the central nervous system, we have used Northern blot hybridization analysis to determine the patterns of expression of seven proto-oncogenes in 20 cell lines established from biopsy specimens of patients with malignant glioma. The following proto-oncogenes are expressed at detectable levels in 30 micrograms of total RNA from most glioma cell lines examined: c-myc (20/20), c-mil/raf-1 (18/18), neu (19/20), c-erbB (19/20), and c-myb (17/20). In contrast, only half of the cell lines expressed detectable c-sis (10/20). In none of the cell lines tested was N-myc (0/20) mRNA detected. Morphologic analysis of these 20 cell lines revealed three different growth patterns: bipolar, epithelial, and pleomorphic-glial. Detectable levels of c-sis mRNA typically occurred with either an epithelial or pleomorphic-glial morphology. The pleomorphic-glial subgroup was also characterized by the expression of glial fibrillary acidic protein.

Suramin: an anticancer drug with a unique mechanism of action.

We administered suramin, an anti-parasitic drug and reverse transcriptase inhibitor, to 15 patients with metastatic cancer. This compound is known to inhibit the binding of growth factors (eg, epidermal growth factor [EGF], platelet-derived growth factor [PDGF], tumor growth factor-beta [TGF-beta]) to their receptors and thus antagonize the ability of these factors to stimulate growth of tumor cells in vitro. There were no complete responses (CRs), four partial responses (PRs) (two of ten adrenal cortex, one of four renal, one of one adult T-cell leukemia-lymphoma [HTLV-1]), and two minimal responses (MRs) (two of ten adrenal cortex). Toxicity included proteinuria (14 patients), reversible liver function test abnormalities (eight), vortex keratopathy (five), adrenal insufficiency (three), coagulopathy secondary to increased circulating levels of glycosaminoglycans (11), and one case of a reversible acute demyelinating polyneuropathy resembling the Guillain-Barrè syndrome. We conclude that suramin is an active agent in the treatment of metastatic cancer, and further work is necessary to define its scope.

Circulating glycosaminoglycan anticoagulants associated with suramin treatment.

A complex coagulopathy appeared in three women receiving suramin as treatment for metastatic adrenocortical carcinoma. Although hepatocellular dysfunction accounted for some of the abnormality, a unique feature of the coagulopathy was the presence of an inhibitor of the thrombin clotting time. The potency of this circulating anticoagulant increased markedly during exacerbations of hepatic injury. The anticoagulant was removed from plasma samples from two of the patients by passage over a column of diethylaminoethyl (DEAE)-Sephacel. It eluted from the DEAE at salt concentrations that removed "high-charge" glycosaminoglycans. Elimination of the purified anticoagulant activity in vitro required a combination of heparitinase and chondroitinase ABC, suggesting that the activity was mediated by both heparan sulfate and dermatan sulfate. Suramin is hypothesized to inhibit enzymes that normally degrade glycosaminoglycans, resulting in accumulation of these substances, which are released from the liver into the circulation during periods of hepatic injury.

Effects of suramin on the function and structure of the adrenal cortex in the cynomolgus monkey.

There have been reports of adrenal failure in patients treated with suramin, an agent that has recently been used as therapy for acquired immune deficiency syndrome. We conducted this study to assess the effect of suramin on adrenal function and structure in a primate, the cynomolgus monkey. Five male monkeys were treated with suramin (800 mg/m2, im) once a week, for 5 weeks. Five other animals (controls) received saline. The treated animals had progressive elevations of plasma ACTH (P less than 0.05) and PRA (P less than 0.02) and decreased serum cortisol responses 30 min after the administration of synthetic ACTH (P less than 0.05) compared to controls. There was disruption of the architecture of the adrenal cortex, a diffuse inflammatory cell infiltrate, and thinning of the zona glomerulosa and zona fasciculata in the suramin-treated animals. We conclude that suramin is toxic to adrenal cortical tissue and might be useful in treating conditions with adrenal cortical hyperfunction, such as adrenal cortical carcinoma and Cushing's syndrome.

c-myc expression in the thyroid. I: Normal, adenomatous, and cancerous thyroid tissue.

Recent investigations have suggested that myc oncogene expression may be important in the development or progression of thyroid tumors. The purposes of the present study were to assess cellular (c)-myc expression in thyroid adenomas (n = 5), as well as in thyroid cancer (n = 4) and in normal thyrocytes (n = 7). Total RNA was prepared by extraction with guanididium thiocyanate and ultracentrifugation through a CsCl2 cushion. 30 micrograms total RNA was size fractionated on a 1% (w/v) agarose/formaldehyde gel and transferred to nylon membranes. These membranes were hybridized to a 32P-labelled third exon c-myc DNA. Following hybridization, blots were washed under high stringency and subjected to autoradiography; radioautographic bands were assessed visually or were quantitated by scanning densitometry. Nodular tissue had approximately the same degree of expression of the 2.4 Kb c-myc message as the surrounding normal tissue from the same gland (0.66 +/- 0.09 vs. 1.0 +/- 0.26, respectively); normal thyrocytes were capable in every instance of expressing the 2.4 Kb c-myc message. Thyroid cancer tissue expressed this message (0.91 +/- 0.17) but only at a level comparable to normal tissue. No other bands of hybridization were detected in any samples. We conclude that c-myc oncogene expression is comparable in normal thyrocytes and in thyroid nodules or thyroid cancer samples. These findings support a role for c-myc in both normal and neoplastic thyrocyte growth.

c-myc expression in the thyroid. II: Thyrocytes and peripheral and intrathyroidal lymphocytes from patients with autoimmune thyroid disease.

Enhanced oncogene expression observed in lymphocytes from patients with systemic lupus erythematosus has suggested the importance of studying oncogene expression and regulation in the cellular events of autoimmune thyroid diseases (AITD). The present study examines oncogene expression in peripheral and intrathyroidal lymphocytes from patients with Hashimoto's disease (HD) and Graves' disease (GD). Intrathyroidal lymphocytes from a patient with primary thyroid lymphoma were also examined. Lymphocytes were isolated by Ficoll-Hypaque gradients, and total RNA was prepared by extraction with guanididium thiocyanate and ultracentrifugation through a cesium chloride cushion. RNA concentrations were determined by O.D. readings at 260/280 nm and each sample subjected to gel electrophoresis with ethidium bromide staining to assure the integrity of the RNA. 30 micrograms total RNA was size fractionated on a 1% (w/v) agarose/formaldehyde gel and transferred to nylon membranes. These membranes were hybridized with nick-translated 32P labelled c-myc DNA (exon III), washed at high stringency and subjected to autoradiography. Specific bands were quantitated by scanning densitometry. Five RNA samples from GD thyroids had 2.4 Kb bands corresponding to c-myc with a mean O.D. (+/- SD) of 0.76 +/- 0.23, whereas 7 from normal thyroid glands had mean O.D. of 1.0 +/- 0.26. Peripheral lymphocytes from 7 GD patients had a mean O.D. of 1.41 +/- 0.25, 4 HD patients had a mean O.D. of 1.05 +/- 0.10 and 2 normal patients had a mean O.D. of 1.4 +/- 0.14. The readings for a sample obtained from intrathyroidal lymphocytes of a patient with HD and thyroid lymphoma were 1.0 and 1.4, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)