Isolated hypoxic hepatic perfusion with tumor necrosis factor-alpha, melphalan, and mitomycin C using balloon catheter techniques: a pharmacokinetic study in pigs

OBJECTIVE: To validate the methodology of isolated hypoxic hepatic perfusion (IHHP) using balloon catheter techniques and to gain insight into the distribution of tumor necrosis factor-alpha (TNF), melphalan, and mitomycin C (MMC) through the regional and systemic blood compartments when applying these techniques. SUMMARY BACKGROUND DATA: There is no standard treatment for unresectable liver tumors. Clinical results of isolated limb perfusion with high-dose TNF and melphalan for the treatment of melanoma and sarcoma have been promising, and attempts have been made to extrapolate this success to the isolated liver perfusion setting. The magnitude and toxicity of the surgical procedure, however, have limited clinical applicability. METHODS: Pigs underwent IHHP with TNF, melphalan, and MMC using balloon catheters or served as controls, receiving equivalent dosages of these agents intravenously. After a 20-minute perfusion, a washout procedure was performed for 10 minutes, after which isolation was terminated. Throughout the procedure and afterward, blood samples were obtained from the hepatic and systemic blood compartments and concentrations of perfused agents were determined. RESULTS: During perfusion, locoregional plasma drug concentrations were 20- to 40-fold higher than systemic concentrations. Compared with systemic concentrations after intravenous administration, regional concentrations during IHHP were up to 10-fold higher. Regional MMC and melphalan levels steadily declined during perfusion, indicating rapid uptake by the liver tissue; minimal systemic concentrations indicated virtually no leakage to the systemic blood compartment. During isolation, concentrations of TNF in the perfusate declined only slightly, indicating limited uptake by the liver tissue; no leakage of TNF to the systemic circulation was observed. After termination of isolation, systemic TNF levels showed only a minor transient elevation, indicating that the washout procedure at the end of the perfusions was fully effective. CONCLUSIONS: Complete isolation of the hepatic vascular bed can be accomplished when performing IHHP using this balloon catheter technique. Thus, as in extremities, an ideal leakage-free perfusion of the liver can now be performed, and repeated, without major surgery. The effective washout allows the addition of TNF in this setting

In vitro and in vivo chemosensitizing effect of cyclosporin A on an intrinsic multidrug-resistant rat colon tumour

Colon tumours are intrinsically resistant to chemotherapy and most of them express the multidrug transporter P glycoprotein (Pgp). Whether this Pgp expression determines their resistance to anticancer agents in patients is not known. We report here on the reversibility of intrinsic multidrug resistance in a syngeneic, solid tumour model. CC531 is a rat colon carcinoma that expresses Pgp, as was shown with the monoclonal antibody C-219. In vitro the sensitivity to doxorubicin, daunorubicin and colchicine was enhanced by the addition of the chemosensitizers verapamil and cyclosporin A (CsA), while the sensitivity to cisplatin was not enhanced. In a daunorubicin accumulation assay verapamil and CsA enhanced the daunorbicin content of CC531 cells. In vivo CsA was injected intramuscularly for 3 consecutive days at a dose of 20 mg kg-1 day-1. This resulted in whole-blood CsA levels above 2 μmol/l, while intratumoral CsA levels amounted to 3.6 μmol/kg. In a subrenal capsule assay the maximal tolerable dose of doxorubicin (4 mg/kg) significantly reduced tumour growth. Doxorubicin at 3 mg/kg was not effective, but in combination with CsA this dose was as effective as 4 mg/kg doxorubicin. These experiments show that adequate doses of the chemosensitizing drug CsA can be obtained in vivo, resulting in increased antitumoral activity of doxorubicin in vivo. The in vitro and in vivo data together suggest that the chemosensitization by CsA is mediated by Pgp. This finding may have implications for the application of CsA and CsA-like chemosensitizers in the clinical setting

Drug resistance in rat colon cancer cell lines is associated with minor changes in susceptibility to cytotoxic cells

The development of resistance to anticancer drugs urges the search for different treatment modalities. Several investigators have reported the concomitant development of drug resistance and resistance to natural killer (NK), lymphokine-activated killer (LAK) or monocyte/macrophage cell lysis, while others described unchanged or even increased susceptibility. We investigated this subject in the rat colon carcinoma cell line, CC531-PAR, which is intrinsically multidrug-resistant (MDR), and in three sublines derived from this parental cell line: a cell line with an increased MDR phenotype (CC531-COL), a revertant line from CC531-COL (CC531-REV), which demonstrates enhanced sensitivity to anticancer drugs of the MDR phenotype, and an independently developed cisplatin-resistant line (CC531-CIS). In a 4-h51Cr-release assay we found no difference in susceptibility to NK cell lysis. No significant differences in lysability by adherent LAK (aLAK) cells were observed in a 4-h assay. In a prolonged 20-h51Cr-release assay an enhanced sensitivity to aLAK-cell-mediated lysis was observed in the revertant, P-glycoprotein-negative cell line and in the cisplatin-resistant cell line (CC531-CIS). None of the cell lines was completely resistant to lysis by aLAK cells. Therefore, a role for immunotherapy in the treatment of drug-resistant tumors remains a realistic option

Simultaneous analysis of gamma-hydroxybutyric acid and its precursors in urine using liquid chromatography-tandem mass spectrometry

We have developed a rapid method that enables the simultaneous analysis of gamma-hydroxybutyrate (GHB) and its precursors, i.e. gamma-butyrolactone (GBL) and 1,4-butanediol (1,4-BD) in urine. The method comprised a simple dilution of the urine sample, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Chromatographic separation was achieved using an Atlantis dC18 column, eluted with a mixture of formic acid and methanol. The method was linear from 1-80 mg/L for GHB and 1,4-BD and from 1-50 mg/L for GBL. The limit of quantification was 1 mg/L for all analytes. The procedure, which has a total analysis time (including sample preparation) of less than 12 min, was fully validated and applied to the analysis of 182 authentic urine samples; the results were correlated with a previously published GC-MS procedure and revealed a low prevalence of GHB-positive samples. Since no commercial immunoassay is available for the routine screening of GHB, this simple and rapid method should prove useful to meet the current increased demand for the measurement of GHB and its precursors. © 2004 Elsevier B.V. All rights reserved.SCOPUS: cp.jinfo:eu-repo/semantics/publishe