Drug-induced DNA modification in buccal cells of cancer patients receiving carboplatin and cisplatin combination chemotherapy, as determined by an immunocytochemical method: interindividual variation and correlation with disease response.

Twenty-six patients with a variety of tumor types were treated according to a phase 1 experimental treatment protocol consisting of repetitive cycles of cis-diammine(1,1-cyclobutanedicarboxylato)platinum(II) (carboplatin, 200-480 mg/m2) at day 1 and cis-diamminedichloroplatinum(II) (cisplatin, 50-100 mg/m2) at day 3. Buccal cells were collected in one or two treatment cycles prior to carboplatin, 24 h after carboplatin, just prior to cisplatin, and approximately 24 h after cisplatin administration. Drug-induced DNA modification was visualized at the single cell level by anti-serum NKI-A59 and quantitated by microdensitometry.

Dose-escalation study of carboplatin (day 1) and cisplatin (day 3): tolerance and relation to leukocyte and buccal cell platinum--DNA adducts.

Carboplatin and cisplatin have similar antitumor activities but different toxicities. Combining these two analogs may be expected to balance the toxicities and allow higher doses of platinum compounds to be administered with tolerable toxicity. To test this concept, a Phase I trial of carboplatin in combination with cisplatin was performed.

Formation of interaction products of carboplatin with DNA in vitro and in cancer patients.

Binding of the cytostatic drug carboplatin to DNA was studied in solution, in RIF-1 and CHO cell lines and in human buccal cells after in vitro or in situ drug exposure. Results were compared with DNA adduction by cisplatin. The rate of binding in solution, determined by atomic absorption spectroscopy, was 35 times lower for carboplatin than for cisplatin.

Continuous infusion carboplatin on a 21-day schedule: a phase I and pharmacokinetic study.

A phase I study with continuous infusion carboplatin for 21 days every 6 weeks using a venous access port and portable pump was performed over a dose range of 12 to 32 mg/m2/d, with increments of 2 mg/m2/d. Forty-four patients received 107 courses (median, two; range, one to nine). World Health Organization (WHO) grade III/IV leukopenia and thrombocytopenia occurred in one of seven patients at 30 mg/m2/d, and in two of six and four of six patients at 32 mg/m2/d.

Antibodies against cisplatin-modified DNA and cisplatin-modified (di)nucleotides.

Cytotoxic effects of cis-diamminedichloroplatinum-(II) (cis-DDP) are thought to be mediated by binding to DNA. Studies on binding of cis-DDP to cellular DNA rely heavily on the availability of specific antibodies. We therefore raised and characterized four rabbit antisera: one against cis-DDP-modified DNA (antiserum NKI-A59) and three others against the cis-DDP-modified (di)nucleotides cis-Pt(NH3)2d(pApG) (NKI-A68), cis-Pt(NH3)2d(GMP)2 (NKI-A10), and Pt(NH3)3dGMP (NKI-A39).

Correlation between cell killing by cis-diamminedichloroplatinum(II) in six mammalian cell lines and binding of a cis-diamminedichloroplatinum(II)-DNA antiserum.

The relationship between cell killing and the binding of the anticancer drug cis-diamminedichloroplatinum(II) (cis-DDP) to DNA was studied in six mammalian cell lines. Two of the human cell lines (COV413B) were of the same origin, comprising one sensitive to cis-DDP and the other with induced resistance to the drug. The four other lines, two rodent (RIF-1, Chinese hamster ovary) and two human (A2780, A1847), were unrelated.

Cellular distribution of cis-diamminedichloroplatinum(II)-DNA binding in rat dorsal root spinal ganglia: effect of the neuroprotecting peptide ORG.2766.

The in situ binding of the anticancer drug cis-diamminedichloroplatinum(II) (cisDDP) to DNA was studied in the rat dorsal root spinal ganglion (DRG), using an antiserum against cisDDP-modified calf thymus DNA in a quantitative immunocytochemical assay. Rats received a dose of cisDDP (1 mg/kg), two times a week, up to a cumulative dose of 15 mg/kg (group I) or 34 mg/kg (group II). Rats of group III were given a single dose of 15 mg/kg.

Single cell analysis of DNA modifications induced by chemical carcinogens and cytostatic drugs.

Antibodies recognizing specific DNA modifications allow the immunocytochemical visualization and quantification of these modifications at the level of the individual cell. Thus, the formation and repair of DNA adducts induced by chemical mutagens and carcinogens and by cytostatic drugs can be studied in very small samples in relation to e.g.

Monitoring of interaction products of cis-diamminedichloroplatinum(II) and cis-diammine(1,1-cyclobutanedicarboxylato)platinum(II) with DNA in cells from platinum-treated cancer patients.

The formation and stability of interaction products between the anti-cancer drug cis-diamminedichloroplatinum(II) (cis-DDP) and DNA were studied in buccal epithelial and urinary cells from ten cancer patients who received cis-DDP-based therapy. Buccal cells were collected 1 h before and 1-2 h after i.v.

Immunocytochemical analysis of DNA adducts in single cells: a new tool for experimental carcinogenesis, chemotherapy and molecular epidemiology.

The immunocytochemical staining of carcinogen-DNA adducts by a double peroxidase-anti-peroxidase (PAP) method is critically described. It is a powerful new tool for the investigation of the initial processes of chemical carcinogenesis--such as metabolic activation of carcinogens, and modification/repair of DNA--at the level of individual, putative target cell types. It is the method of choice if the cell populations are too small for determination of adducts in isolated DNA, or if information on the tissue distribution of DNA damage is needed.

Immunocytochemical detection of interaction products of cis-diamminedichloroplatinum(II) and cis-diammine(1,1-cyclobutanedicarboxylato)platinum(II) with DNA in rodent tissue sections.

Calf thymus DNA was modified in vitro by cis-diamminedichloroplatinum(II) (cisDDP), complexed with methylated bovine serum albumin and used to immunize rabbits. The anti-cisDDP-DNA antiserum obtained was applied in a double peroxidase-antiperoxidase staining procedure to localize cisDDP-DNA and cis-diammine(1,1-cyclobutanedicarboxylato)platinum(II) (CBDCA)-DNA interaction products in cryostat tissue sections of mice and rats. Rats received cisDDP (0-10 mg/kg) and were killed after 24 h.

Macrophage-like tumor cells as tools to study chemoattractive activity.

Macrophage-like tumor cells can be obtained in large quantities as rather homogeneous populations, making these cells useful for chemotaxis assays. Therefore, macrophage-like cells J774A, WEHI-3, P388D1, IC-21, and NCTC 1469, all of murine origin, and U937 of human origin, were tested for chemotactic activity to a number of chemoattractive agents, such as casein, an N-formyl tetrapeptide (N-formyl-L-norleucyl-L-leucyl-L-phenylalanyl-L-tyrosine), and culture supernatants of murine SL2 lymphoma cells. J774A and WEHI-3 macrophage-like cells of murine (BALB/c) origin expressed the strongest chemotactic activity to casein and N-formyl tetrapeptide, respectively.

A role for mast cells and the vasoactive amine serotonin in T cell-dependent immunity to tumors.

The involvement of mast cells in anti-tumor resistance was studied by employing 2 strains of mast cell deficient but otherwise immunocompetent mice on a C57BL/6 (H-2b) background (W/Wv and Sl/Sld) and their respective normal +/+ littermate controls. Sensitization of control mice with irradiated semisyngeneic B16 melanoma cells (H-2b) resulted in protection against subsequent challenge with viable B16 cells, in contrast to sensitization of either W/Wv or Sl/Sld mice. The involvement of serotonin in antitumor resistance was studied by employing 2 serotonin active drugs: reserpine, that depletes mast cells of serotonin; and methysergide, a serotonin antagonist.