Rats with mammary cancer treated with toremifene and interferon: morphometry and needle aspiration biopsy for determination of ATP and 14C-fluorodeoxyglucose content

Oral administration of the broad-spectrum antibiofilm compound toremifene inhibits Candida albicans and Staphylococcus aureus biofilm formation in vivo

We here report on the in vitro activity of toremifene to inhibit biofilm formation of different fungal and bacterial pathogens, including Candida albicans, Candida glabrata, Candida dubliniensis, Candida krusei, Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis. We validated the in vivo efficacy of orally administered toremifene against C. albicans and S. aureus biofilm formation in a rat subcutaneous catheter model. Combined, our results demonstrate the potential of toremifene as a broad-spectrum oral antibiofilm compound.

Pharmacokinetics and metabolism of 2-[18F]fluoro-2-deoxy-D-glucose (FDG) in mammary tumors of antiestrogen-treated rats

Attempts are being made to evaluate 2-[18F]fluoro-2-deoxy-D-glucose (FDG) as a noninvasive marker of therapy response in malignant tumors. We studied rats with 7,12-dimethylbenzanthracene (DMBA)-induced mammary carcinomas by measuring the differential absorption ratio (DAR) and the metabolites of FDG in tumor homogenates. Half the rats were treated with the antiestrogen toremifene for 14 days and half were untreated. The histology of the tumors was studied by morphometry. The animals were killed 15, 45 or 240 min after injection. Regardless of whether the rats received toremifene or not, the fractional change in tumor volume correlated better with the DAR at 15 min [r = 0.284 (untreated) and r = 0.721 (treated)] and at 240 min [r = 0.932 (untreated)], than at 45 min [r = -0.137 (untreated) and r = 0.265 (treated)]. Inverse relations were found for the fraction of unmetabolized FDG and change in tumor volume [r = 0.070 (45 min) and r = -0.872 (240 min) for untreated tumors and r = -0.963 (15 min) and r = -0.715 (45 min) for treated tumors]. The DAR and the fraction of unmetabolized FDG correlated also [r = -0.420 (15 min), r = -0.647 (45 min) and r = -0.976 (240 min) for untreated tumors, and r = -0.963 (15 min) and r = -0.213 (45 min) for treated tumors]. No significant therapy-induced morphometrical changes were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Combination treatment based on metabolic effects of dinaline

The human colon carcinoma cell line SW 707 was exposed for up to 72 h to the new antineoplastic agent 4-amino-N-(2'-aminophenyl)benzamide (GOE 1734, dinaline). Thereafter, uptake measurements with fluorodeoxy-[14C]glucose (FdGlc) were performed and cell-cycle fractions as well as adenine nucleotide pools were determined by flow cytometry and HPLC. One day after a 24 h exposure to 20-540 microM dinaline a 2.0-to 2.5-fold enhancement of FdGlc uptake was observed, and the values after 48-h or 72-h incubations showed a 2.5- to 3.5-fold or a 2.0-fold increase respectively. For all periods of exposure a diminished S phase (3%-71% of control) was found initially after incubation, demonstrating the antiproliferative effect of dinaline, with total recovery after 1 day. Adenine nucleotide pools were not diminished concomitantly. The enhanced FdGlc uptake caused by dinaline was the basis for choosing 2-deoxyglucose (dGlc) as the combination partner, which acts as an antimetabolite to enzymes involved in glucose metabolism. Several combinations of dinaline and dGlc were analyzed for their effects on growth inhibition. Almost 50% additional decrease in cell number as compared to monotherapy with dinaline was found after coexposure to 12 mM dGlc and 20 microM dinaline 24 h after incubation. Similar effects were observed 2 days after incubation with the two drugs. After 3 days, the cell numbers reached monotherapy levels. Since the cytostatic effect of dinaline could be enhanced by dGlc although incubation with dGlc alone caused no changes in cell number, the combined effect of both agents is synergistic. These results imply that dinaline might have applications in combination treatment in vivo.

Determination of 2-fluoro-2-deoxy-D-glucose uptake and ATP level for evaluating drug effects in neoplastic cells

The glucose analogue 2-fluoro-2-deoxy-D-glucose (FDG) was used to study chemosensitivity of two human ovarian cancer cell lines and of murine L1210 cells. Cell viability was determined by measuring intracellular adenosine triphosphate (ATP) with a bioluminescence method, which has been shown to correlate closely with trypan blue, stem cell, and [3H]TdR assays. All three cell lines were sensitive to cytostatic drugs, which exerted a parallel decrease in the intracellular FDG and ATP levels. The two measures correlated positively (r = 0.66, P less than 0.001), indicating that FDG uptake is closely linked with ATP production. Relatively low hexokinase (HK)-to-glucose 6-phosphatase (HK/G6-Pase) ratios were measured, which suggests that the metabolic trapping of FDG 6-phosphate within the cytosol is incomplete. Apparently, these cell lines may not depend exclusively on glycolysis for their energy requirement. We conclude that cell killing caused by cytostatic drugs is associated with a decreased ATP content and FDG uptake. This indicates that not only ATP but also FDG may be used to study drug effects in vitro.