Effects of sodium warfarin and sodium heparin plus anticancer agents on growth of rat C6 glioma cells.

The effects of racemic sodium warfarin (warfarin) and sodium heparin (heparin) on brain tumor cells were assessed in the rat C6 glioma cell line. After anticoagulant treatment lasting up to 5 days, cell growth was not inhibited by warfarin at low doses (10(-4) to 10(-5) M), but both cell growth and cellular adherence to culture plates were inhibited at high doses (10(-3) to 10(-2) M). Sodium heparin, even at high doses, did not affect cell growth or adherence. Warfarin (10(-3) M) significantly decreased and heparin (12.6 U/ml) had no effect on [3H]thymidine and [14C]leucine incorporation after 3- or 24-hour anticoagulant treatment. Colony formation studies examined the effects of 24-hour warfarin (10(-3) M) or heparin (12.6 U/ml) pretreatment plus a 2-hour incubation with one of seven anticancer agents. Supra-additive toxic effects were produced by warfarin plus chlorambucil, heparin plus chlorambucil, heparin plus carmustine, and heparin plus teniposide. At low doses of warfarin (10(-5) M) or heparin (0.126 U/ml), heparin plus carmustine and heparin plus teniposide remained synergistic.

Megestrol acetate v tamoxifen in advanced breast cancer in postmenopausal patients.

One hundred six postmenopausal patients with advanced breast cancer received megestrol acetate or tamoxifen as primary therapy. Response to therapy was comparable for the two agents, with no organ site preference observed for either agent. The median duration of remission was also comparable for the two agents. Both treatments were well tolerated, with weight gain being the most common side effect observed. Initial results of another ongoing study suggest that megestrol acetate is as effective as tamoxifen in hormone-sensitive breast cancer in which receptors have been identified.

Sectional analysis of tumor colony growth in the soft-agar assay: effects of oxygen.

Soft-agar clonogenicity of L1210 mouse leukemia cells and of xenografts of a human melanoma and a carcinoma of the cervix was studied sectionally by the sizes of the colonies grown under hypoxic gradients and aerobic condition. Soft-agar plating efficiency was increased in cultured L1210 cells with decreasing oxygen concentrations. The growth of both cultured L1210 cells and their BDF1 ascites was better in 5% oxygen than in 20% oxygen. Although soft-agar colony development of both melanoma and cervical carcinoma was significantly better in 5% oxygen, the former has a secondary preference for a hypoxic atmosphere and the latter, for an aerobic condition.

Cooperative evaluation of human tumor chemosensitivity in the soft-agar assay and its clinical correlations.

In supporting the human-tumor cloning effort of the Southwest Oncology Group, we conducted an independent retrospective study to evaluate the clinical correlations of the soft-agar colony-forming assay developed by Hamburger and Salmon (1977). This study was made with the cooperation of 76 clinicians and 11 hospitals in Greater New Orleans. In a 10-month trial (July 1982 to May 1983), we received 134 human tumors of 26 classifications and achieved 76% success in colony growth from 122 plated samples. Retrospective correlations between the in vitro chemosensitivity of tumor colonies and clinical drug responses were made possible in 31% of the patients. Evaluation of 45 in vitro and in vivo associations indicated a combined sensitivity of 0.65 and a specificity of 0.68 for the assay. Technical refinements and the selectivity of the assay are discussed.

Pharmacologic assessment of regimen chemosensitivity in the soft-agar assay: effect of oxygen on human tumors.

The influence of oxygen on the growth and the in vitro chemosensitivity of human tumor cells was studied in the soft-agar assay. Tumor cells of pancreatic and ovarian origin prefer a reduced oxygen atmosphere for colony formation, whereas those of pulmonary origin grow better in 20% oxygen. Depending on the physiologic oxygen tension and the histologic origin of a particular cancer type, the in vitro chemosensitivity of many drug obtained with the conventional culture system could be inadequately assessed. The in vitro responses of tumor cells to combinations of drugs were measured by the regimen efficacy index (REI) method. The REI delineates the possible regimen enhancement or regimen default based on the in vitro chemosensitivity of the individual agents tested in the assay. In vitro regimen enhancement was observed only in ascites incubated in a reduced oxygen atmosphere with two-drug combinations. However, regardless of the oxygen gradients used, regimen default was seen in cancer cells of solid tumors treated with all combinations of drugs tested. This study suggests further investigation on the effects of oxygen in the soft-agar assay, and proposes the novel use of the REI method for evaluating the in vitro regimen chemosensitivity of human tumor cells.

Relative bioavailability of 4,4'-dihydroxybenzophenone-2,4-dinitrophenylhydrazone (A-007) in rats and monkeys.

4,4'-Dihydroxybenzophenone-2,4-dinitrophenylhydrazone (A-007) is being evaluated for its anticancer activities in melanoma, breast cancer, Kaposi's sarcoma and lymphoproliferative disorders. A single oral dose of 1 g/kg of A-007 in rats resulted in prolonged and low plasma levels, typically less than 150 ng/ml for several days. Similarly, a single oral dose of 5 g/kg of A-007 in monkeys resulted in prolonged and low plasma levels, typically less than 22 ng/ml for several days. Oral bioavailability data suggests that this is not an efficient mode of drug administration and availability diminishes as one progresses from rodents to primates (relative oral bioavailability 2%); thus suggesting an alternative form of drug delivery is required in higher species. A-007 is not detected in plasma after a 0.25% gel is applied topically to the skin daily for 28 days. Early clinical support the topical use of A-007 to treat cutaneous metastasis for human breast cancer. The present data further support a dermal approach for the use of A-007 to treat metastatic cutaneous cancers.

Acyl derivatives of demethylpenclomedine, an antitumor-active, non-neurotoxic metabolites of penclomedine.

PURPOSE: The purpose of this investigation was to compare the antitumor activities of a series of acyl derivatives of 4-demethylpenclomedine (DM-PEN), the major plasma metabolite of penclomedine (PEN) observed to be an active antitumor agent in vivo and non-neurotoxic in a rat model with that of DM-PEN. METHODS: Acyl derivatives were prepared from DM-PEN and evaluated in vivo against human MX-1 breast tumor xenografts implanted subcutaneously (s.c.) or intracerebrally (i.c.). Several derivatives were also evaluated against other human tumor xenografts and murine P388 leukemia cell lines. RESULTS: Several of the acyl derivatives were found to be superior to DM-PEN against MX-1, human ZR-75-1 breast tumor, human U251 CNS tumor and the P388 leukemia parent cell line and lines resistant to cyclophosphamide and carmustine. 4-Demethyl-4-methoxyacetylpenclomedine showed inferior activity to current clinical brain tumor drugs against a glioma cell line, superior activity to temozolomide and procarbazine against the derived mismatch repair-deficient cell line, and superior activity to cyclophosphamide and carmustine but inferior activity to temozolomide against two ependymoma cell lines, all of which were implanted s.c. CONCLUSION: Proposed mechanisms of activation and action of DM-PEN and the acyl derivatives support the potential clinical superiority of the acyl derivatives.

Exposure to male siblings facilitates the response to estradiol in sexually naive female prairie voles.

Female prairie voles undergo induced estrus, and require both physical contact with males and exposure to male urine to become reproductively active. This study attempted to determine if physical contact with males enhanced female response to estradiol. Two groups of sexually naive females were tested. One was reared without any exposure to males after weaning, and the other was reared with sibling males to 60 days of age. Sibling males were used because females avoid direct contact with the urine of related males, allowing for the establishment of a group of females that experienced physical contact in the relative absence of exposure to male pheromones associated with urine. Females were then subcutaneously injected with 0.5 microg estradiol benzoate once a day for 7 days. Sexual receptivity was tested with novel adult males 48 h and 168 h after the first injection. There was a significant difference between the treatment groups, with 10% of sexually naive females reared without sibling males displaying lordosis compared to 70% of females raised with sibling males. The results indicate that exposure to sibling males significantly increased a female's behavioral response to estradiol.

Adoptive immunotherapy of advanced renal cell cancer using PHA-stimulated autologous lymphocytes.

Patients with advanced renal cell carcinoma, previously failed maximal treatment with standard chemo-hormonal-radiation therapies, were treated with plant lectin phytohemagglutinin (PHA)-stimulated autologous peripheral blood lymphocytes in a 10-year study with a 16-year follow up period. In a phase I-II setting, 52 patients were given subcutaneously 40-80 x 10(6) PHA-stimulated lymphocytes weekly for 3 weeks and then escalated to a maximum number of 80 x 10(9) lymphocytes over the next 9 weeks at 3 week intervals. In vitro blastogenesis under study conditions (10 micrograms/ml PHA for 72 hr) measured by [3H]thymidine uptake was optimal with lymphocyte stimulating indexes approaching 300. Lymphocytes obtained from patients with breast cancer, melanoma and renal cell carcinoma responded to PHA similarly to those from normal volunteers. All patients that responded developed erythematous reactions at the sites of injection; malaise, joint paint and chill-fever for 24-48 hr. The patients that responded the best were those with at least 1 positive reaction out of 4 skin tests (tuberculosis, yeast, dermatophytin, mumps) prior to therapy. All toxicity was transient and did not exceed Grade I based on criteria of the Southwest Oncology Group. The majority of patients developed a lymphopenia in the first 24 hr followed by a lymphocytosis 48-72 hr later. For some patients the lymphocytosis was as much as 30% atypical lymphocytes. Of 41 evaluable patients, there were 5 complete responses, 8 partial responses, 3 stable diseases, and 25 progressive disease. The overall response rate was 32% and the median survival was 2.8 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparative dermal pharmacology and toxicology of 4,4'-dihydroxybenzophenone-2,4-dinitrophenylhydrazone (A-007) in rodents and primates.

4,4'-Dihydroxybenzophenone-2,4-ditrophenylhydrazone (A-007) has demonstrated anticancer activities, when administered topically to patients with metastatic cancer to the skin. Acute, subacute and subchronic dermal studies with A-007 in adult rabbits, rats, guinea pigs and monkeys failed to demonstrate local or systemic toxicity when applied topically as a 0.25% gel. A-007 did not penetrate the dermal lymphatics and did not produce detectable levels of A-007 in the plasma when applied as a 0.25% gel topically to skin. In the above studies, topically administered A-007 stimulated local sub-epithelial and dermal lymphocyte modulation, with increased CD8+ cytotoxic lymphocytes (CTL) noted, in guinea pig skin. Generally topical A-007 is well tolerated and may have useful immune modulation properties.

Comparative preclinical toxicology and pharmacology of 4,4'-dihydroxybenzophenone-2,4-dinitrophenylhydrazone (A-007) in vitro and in rodents and primates.

4,4'-Dihydroxybenzophenone-2,4-dinitrophenylhydrazone (A-007) is being evaluated for its anticancer activities. Acute, subacute and chronic oral, dermal, opthalmic and dermal LD50 and acceptance studies in adult mice, rats, rabbits and monkeys demonstrated some vomiting at 5 g/kg doses in monkeys but otherwise no unacceptable toxicities. In vitro, T.I. for A-007 were calculated using murine bone marrow GM-CFC and human cancer cell lines. A relative oral bioavailability factor of 2% was calculated for rats and monkeys for plasma A-007. Non-compartmental pharmacokinetic analysis suggests enterohepatic circulation. Plasma A-007 could not be detected after applying a 0.25% gel topically. Generally, A-007 is well tolerated.

Mandibular reconstruction. Current state of the art.

At the present time several techniques of bone grafting for restoration of mandibular defects are being employed. These methods are well established by clinical trials and animal research. Other methods are in the experimental stage. Regardless of the technique utilized it remains paramount that the surgeon plan the initial procedure with great care as each failure results in diminished blood supply to the graft bed and makes subsequent procedures less likely to succeed. The well known principles of bone grafting involve establishing good nutritional status of the patient, proper preparation of the graft bed by insuring adequate soft tissue and adequate blood supply, elimination of infection from the graft bed, provision of adequate fixation and immobilization of the graft, and careful closure of soft tissues to prevent hematoma formation. These principles remain inviolable if the procedure is to succeed.

Tumor physiology and charge dynamics of anticancer drugs: implications for camptothecin-based drug development.

Charge is an important characteristic of drug molecules, since ionization sites determine the pKa at a particular pH. The pKa in turn can affect many parameters, including solubility, dissolution rate, reaction kinetics, formulation, cell permeability, tissue distribution, renal elimination, metabolism, protein binding and receptor interactions. The impact of charge dynamics is amplified in human solid tumors that exhibit the glycolytic phenotype and associated acidic extracellular microenvironment. This phenotype is driven by hypoxia and creates a pH gradient in tumors that favors uptake of weak acids and exclusion of weak bases. Established anticancer drugs exhibit a range of pKa's and thus variable ability to exploit the tumor pH gradient. The camptothecins are a prime example as they represent a diverse class of approved anticancer drugs and drug candidates whose charge distribution varies with pH. An in silico method was used to predict charge distribution of camptothecins at physiological versus acidic pH in both the lactone and carboxylate forms. A significant amount of uncharged carboxylate was predicted at acidic pH that could enter tumor cells and accumulate in mitochondria to inhibit mitochondrial topoisomerase I. A model is presented to describe the charge dynamics of a new camptothecin analog and the impact on nuclear and mitochondrial mechanism(s) of action. This example illustrates the importance of integrating tumor physiology and charge dynamics into anticancer drug development.