| 1. |
- Ceberg, Crister, et al.
(author)
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Enhanced boron uptake in RG 2 rat gliomas by electropermeabilization in vivo--a new possibility in boron neutron capture therapy
- 1994
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In: Anti-Cancer Drugs. - 0959-4973. ; 5:4, s. 463-466
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Journal article (peer-reviewed)abstract
- Accumulation of boron in tumor tissue is an indispensable requirement for boron neutron capture therapy and it is important that the uptake is as high as possible. In this work we have studied the influence of electropermeabilization in vivo on the uptake of boron in normal and RG 2 glioma bearing Fischer 344 rats. Two different boron compounds, a sulfhydryl boron hydride (BSH) and a boronated porphyrin (BOPP), have been investigated. The rats were infused intravenously during 5 min with 175 micrograms BSH/g body weight or 12 micrograms BOPP/g body weight. Two electrodes were placed 5 mm apart in the brain and electropermeabilization was performed with eight square 400 V pulses at 4 and 7 min after the end of the infusion. After 6 h the animals were killed, and the boron content in the tumors and the surrounding brain was measured with neutron-activated autoradiography. In electropermeabilized healthy animals the BOPP uptake was low and limited to the electrode lesions, whereas BSH was spread extensively throughout the hemisphere. Rats with gliomas showed doubled (BOPP) to 10-fold (BSH) uptake of boron in the tumor when electropermeabilization was performed as compared with untreated animals. We conclude that electropermeabilization in the future may provide an interesting possibility to increase the uptake of certain boron compounds before neutron capture therapy.
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| 2. |
- Cirenajwis, Helena, et al.
(author)
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Reduction of the putative CD44+CD24- breast cancer stem cell population by targeting the polyamine metabolic pathway with PG11047.
- 2010
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In: Anti-Cancer Drugs. - 0959-4973. ; 21:10, s. 897-906
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Journal article (peer-reviewed)abstract
- Cancer stem cells (CSCs) are considered to be of particular concern in cancer as they possess inherent properties of self-renewal and differentiation, along with expressing certain genes related to a mesenchymal phenotype. These features favour the promotion of tumour recurrence and metastasis in cancer patients. Thus, the optimal chemotherapeutic treatment should target the CSC population, either by killing these cells and/or by inducing their transition to a more differentiated epithelial-like phenotype. Experiments were carried out on the trastuzumab-resistant human epidermal growth factor receptor 2-overexpressing breast cancer cell line JIMT-1 to unravel the chemotherapeutic effects of the polyamine analogue [N,N]bis(ethyl)-cis-6,7-dehydrospermine (PG11047) and of the polyamine biosynthetic inhibitor 2-difluoromethylornithine (DFMO) on the CD44CD24 CSC population. Furthermore, effects on the properties of self-renewal and epithelial/mesenchymal markers were also investigated. Treatment with PG11047 reduced the CD44CD24 subpopulation of JIMT-1 cells by approximately 50%, inhibited and/or reduced self-renewal capability of the CSC population, decreased cell motility and induced expression of mesenchymal to epithelial transition-associated proteins that are involved in promoting an epithelial phenotype. By contrast, DFMO slightly increased the CD44CD24 subpopulation, increased cell motility and the level of mesenchymal-related proteins. DFMO treatment reduced the self-renewal capability of the CSC population. Both PG11047 and DFMO reduced the expression of the human epidermal growth factor receptor 2 protein, which is correlated to malignancy and resistance to trastuzumab in JIMT-1 cells. Our findings indicate that treatment with PG11047 targeted the CSC population by interfering with several stem cell-related properties, such as self-renewal, differentiation, motility and the mesenchymal phenotype.
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| 3. |
- Ekblad, Lars, et al.
(author)
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Reduced drug accumulation is more important in acquired resistance against oxaliplatin than against cisplatin in isogenic colon cancer cells.
- 2010
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In: Anti-Cancer Drugs. - 0959-4973. ; 21, s. 523-531
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Journal article (peer-reviewed)abstract
- Preclinical studies have indicated that there is only partial cross-resistance between cisplatin and oxaliplatin. The molecular background for this is incompletely known. To investigate the differences in resistance, we rendered a colon cancer cell line (S1) resistant against cisplatin and oxaliplatin and characterized the subclones with regard to cross-resistance, platinum uptake, and gene expression profiles. Four oxaliplatin and four cisplatin-resistant cell lines were produced from S1 by step-wise increasing the concentrations of the drugs in the growth medium. Cytotoxicity was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and platinum accumulation in cell lysates and DNA preparations by inductively coupled plasma mass spectroscopy. Gene expression was investigated by cDNA microarrays. The protein expression of the ATP-binding cassette B1 (ABCB1) was measured by immunohistochemistry. The cisplatin-resistant cell lines were 1.5-6.2-fold resistant against cisplatin and the oxaliplatin-resistant sublines 2.6-17-fold resistant against oxaliplatin. There was a limited degree of cross-resistance. Oxaliplatin resistance could be explained to a larger degree by reduced drug accumulation whereas mechanisms for increased tolerance against platinum incorporation in DNA seemed to be of higher importance for resistance against cisplatin. A greater number of ABC transporters were upregulated in the oxaliplatin-resistant cell lines compared with those selected for cisplatin resistance. ABCB1 was highly overexpressed in the three most oxaliplatin-resistant sublines, but significantly underexpressed in the two most cisplatin-resistant cell lines. This was also confirmed by immunohistochemistry. However, functional tests did not show any increase in ABCB1 transport activity in the oxaliplatin-resistant sub-lines compared with S1.
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| 4. |
- Holst, Martina, et al.
(author)
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Molecular mechanisms underlying N1, N11-diethylnorspermine-induced apoptosis in a human breast cancer cell line.
- 2008
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In: Anti-Cancer Drugs. - 0959-4973. ; 19:9, s. 871-883
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Journal article (peer-reviewed)abstract
- Polyamine analogue treatment results in growth inhibition and sometimes in cell death. Therefore, polyamine analogues are considered in the treatment of cancer; however, the cellular properties that govern sensitivity are not known. The objective of this study was to elucidate molecular mechanisms behind apoptosis induced by the polyamine analogue N, N-diethylnorspermine (DENSPM). Four different breast cancer cell lines were treated with DENSPM. Cell death was evaluated with flow cytometry and a caspase 3 assay. The levels of a number of proapoptotic and antiapoptotic proteins in subcellular compartments were evaluated with western blot. In the most sensitive cell line, DENSPM treatment induced the release of cytochrome c from mitochondria, resulting in activation of caspase 3 but without decreasing the mitochondrial transmembrane potential. However, in the three other cell lines DENSPM treatment did not induce extensive cell death. This is partly explained by the high levels of antiapoptotic proteins Bcl-2 and Bad and low levels of proapoptotic proteins Bax and procaspase 3 in these three cell lines. The results are also partly explained by the degree of activation of the catabolic enzyme spermidine/spermine-N-acetyltransferase and polyamine pool reduction achieved by DENSPM treatment. Our results show that the protein profile of proapoptotic and antiapoptotic proteins may contribute to the outcome to treatment with the polyamine analogue DENSPM. The results also indicate that it should be possible to find molecular markers for sensitivity to DENSPM that could be used in the clinic to predict sensitivity to a polyamine analogue.
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| 5. |
- Jönsson, Peter, et al.
(author)
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Methotrexate concentrations in cerebrospinal fluid and serum, and the risk of central nervous system relapse in children with acute lymphoblastic leukaemia
- 2007
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In: Anti-Cancer Drugs. - 0959-4973. ; 18:8, s. 941-948
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Journal article (peer-reviewed)abstract
- The aim of the study was to characterize the relationship between the pharmacolkinetics of methotrexate in serum and concentrations in the cerebrospinal fluid, and to analyse the association to risk of a central nervous system relapse in children with acute lymphoblastic leukaemia. In this retrospective study, 353 children with acute lymphoblastic leukaemia treated with high-dose methotrexate according to the Nordic Society of Pediatric Haematology and Oncology-92 acute lymphoblastic leukaemia protocol were studied. Data from 18 patients with a subsequent central nervous system relapse and 335 event-free patients were available. In 34 patients the methotrexate concentrations were monitored repeatedly during each 24-h methotrexate intravenous infusion and a cerebrospinal fluid sample was taken at the end of the infusion. Using statistics separating interindividual and intraindividual variability, methotrexate concentration in cerebrospinal fluid was found to be significantly dependent upon both serum concentrations at the end of infusion and the area under the concentration curve in serum (P<0.0017 and <0.002, respectively). The logistic regression analysis revealed that high patient median serum methotrexate concentrations at the end of infusion were significantly associated with decreased risk for a central nervous system relapse in the standard risk group (P=0.02) and the number of courses with a calculated cerebrospinal fluid concentration of more than 1 mu mol/l (P=0.048) with a decreased risk of a central nervous system relapse in the combined (standard risk and intermediate) risk group. In conclusion, methotrexate concentrations in cerebrospinal fluid are dependent on methotrexate concentrations in serum and serum area under the concentration curve. Multivariate analysis indicates that an increased exposure to methotrexate is related to decreased risk for central nervous system relapse.
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| 6. |
- Myhre, Louise, et al.
(author)
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Different cell cycle kinetic effects of N1,N11-diethylnorspermine-induced polyamine depletion in four human breast cancer cell lines.
- 2008
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In: Anti-Cancer Drugs. - 0959-4973. ; 19:4, s. 359-368
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Journal article (peer-reviewed)abstract
- Polyamine analogues are presently undergoing clinical evaluation in the treatment of cancer. To better understand under what circumstances treatment with a polyamine analogue will yield beneficial results, we have investigated the effect of N,N-diethylnorspermine (DENSPM) on cell cycle kinetics of the human breast cancer cell lines SK-BR-3, MCF-7, HCC1937, and L56Br-C1. A bromodeoxyuridine-DNA flow cytometry method was used to evaluate the treatment with 10 micromol/l DENSPM on cell cycle kinetics. A correlation between polyamine pool size after DENSPM treatment and cell cycle kinetic effects was found. The most sensitive cell cycle phase was the S phase, followed by an effect on the G2+M phase and then the G1/S transition. The levels of a number of cell cycle regulatory proteins such as cyclin E1, cyclin A2, and cyclin B1 were lowered by DENSPM treatment, which may explain the effects on cell cycle kinetics. The two cell lines that were most sensitive to DENSPM treatment belong to the basal-like subtype of breast cancer and they were deficient with respect to p53, BRCA1, and RB1.
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| 7. |
- Myhre, Louise, et al.
(author)
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Normal-like breast cells, but not breast cancer cells, recovered from treatment with N ',N ''-diethylnorspermine
- 2009
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In: Anti-Cancer Drugs. - 0959-4973. ; 20:4, s. 230-237
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Journal article (peer-reviewed)abstract
- A number of polyamine analogs are currently used in various clinical trials as cancer treatment and it is important to investigate their effects not only on cancer cells but also on normal cells. Treatment with polyamine analogs depletes cells of polyamines and inhibits cell proliferation, but the analogs cannot take over the normal function of the natural polyamines in the cell. In this study, the normal-like breast epithelial cell line MCF-10A was treated with the polyamine analog N',N ''-diethylnorspermine (DENSPM). The cells were then studied using a bromodeoxyuridine-DNA flow cytometry method as well as western blot. The ability of both normal-like and breast cancer cells to recover from DENSPM treatment was also studied. DENSPM treatment of MCF-10A cells resulted in a prolongation of the S and G(2) + M phases, followed by a G(1)/S block. The p53/p21/RB1 pathway was involved in the G(1)/S block as shown by increased levels of p53 and p21 detected by western blot. Decreased levels of cyclin E1, cyclin A2, and cyclin B1 in DENSPM-treated cells can explain the prolongation of cell cycle phases that occurred before the G(1)/S block. We also show that MCF-10A cells rapidly recover from DENSPM-induced growth inhibition in contrast to four human breast cancer cell lines. The goal of cancer treatment is to cause minimal and reversible damage to normal cells, while cancer cells should be eliminated. Altogether, the data show that treatment with polyamine analogs spares normal cells, while negatively affecting the cancer cells. Anti-Cancer Drugs 20:230-237 (C) 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins.
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| 8. |
- Okroj, Marcin, et al.
(author)
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A novel mechanism of action of the fumagillin analog, TNP-470, in the B16F10 murine melanoma cell line
- 2005
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In: Anti-Cancer Drugs. - 0959-4973. ; 16:8, s. 817-823
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Journal article (peer-reviewed)abstract
- TNP-470, a semisynthetic derivative of fumagillin, is an acknowledged angiogenesis inhibitor, presently undergoing clinical trials. It exerts an anti-proliferative effect directed against endothelial cells. This effect is known to be based on cell cycle inhibition effected by the p53/p21 pathway. We observed short-term toxicity of TNP-470 in the B16F10 murine melanoma cell line in vitro and investigated the mechanism of action. Cell death occurred as soon as 2 h after the addition of TNP-470, without typical apoptotic features. The toxic effect could be modulated and it depended on the type of culture medium or supplementation with anti-oxidants. Addition of N-acetylcysteine protected B16F10 cells from TNP-470-induced death and inhibited an increase in the generation of reactive oxygen species (ROS), which are detected by the 2',7'-dichlorodihydrofluorescein diacetate probe. We conclude that TNP-470 can induce intracellular generation of ROS, which act toxically inside B16F10 cells. One may suggest that this novel activity of TNP-470 might be beneficial in some cases, but it could also be responsible for some undesirable side-effects. The possibility of its modulation gives a prospect for controlling the action of this potential drug and probably its derivatives.
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| 9. |
- Riesbeck, Kristian
(author)
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Cisplatin at clinically relevant concentrations enhances interleukin-2 synthesis by human primary blood lymphocytes
- 1999
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In: Anti-Cancer Drugs. - 0959-4973. ; 10:2, s. 219-227
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Journal article (peer-reviewed)abstract
- Cytotoxic drugs influence the expression of certain genes in cancer cells. Cisplatin has recently been shown to modulate interleukin (IL)-1 and tumor necrosis factor (TNF)-α production in macrophages. In this study, we wanted to investigate whether cisplatin interferes with the IL-2, IL-2 receptor (IL-2R), interferon (IFN)-γ, and TNF-α expression in phytohemagglutin-stimulated human peripheral blood lymphocytes. IL-2 was analyzed in a bioassay, while IFN-γ and TNF-α were measured by ELISA. Northern blots were performed to quantify steady-state cytokine mRNA levels. Furthermore, T cell subsets and IL-2R surface expression were analyzed by means of flow cytometry. A maximum stimulatory effect on IL-2 production (1.8-fold increase) was observed with cisplatin at 5-10 μM while IFN-γ and TNF-α synthesis and IL-2R density were unaffected. However, cisplatin-treated cells displayed enhanced IL-2, IL-2R, IFN-γ and TNF-α mRNA levels compared to drug-free controls. Cisplatin did not prolong cytokine mRNA half-life as revealed with the transcriptional inhibitor actinomycin D. In contrast to an inhibited growth of CD4+ T lymphocytes, CD3+CD8+ cell density was unaffected at intermediate cisplatin concentrations (10 μM). Bleomycin, carboplatin, doxorubicin, novobiocin or etoposide, which were included for comparison, did not interfere with IL-2 expression. Our data imply that cisplatin most likely stimulated cytokine transcription via a putative stress induced signaling pathway.
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| 10. |
- Sjöholm, H, et al.
(author)
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Necrosis of malignant gliomas after intratumoral injection of 201Tl in vivo in the rat
- 1995
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In: Anti-Cancer Drugs. - 0959-4973. ; 6:1, s. 109-114
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Journal article (peer-reviewed)abstract
- Fourteen adult Fischer 344 rats were inoculated in vivo unilaterally in the caudate nucleus in the brain with malignant RG 2 glioma cells. By 3 weeks a tumor with a diameter of 3-6 mm normally develops. Ten animals which survived the repeated periods of anesthesia and thallium (Tl) injections (intratumorally three times of 201Tl, 15-23 days after inoculation) showed a prolonged retention of radioactivity at the site of injection with no uptake in other organs except for the kidneys. Singular circumscribed necroses were found post-mortem at the site of injection, comprising malignant glioma tumor tissue, which in six animals was absent, in three animals was markedly reduced in size compared with controls and in one animal had the expected size. In four animals metastases were found in distant locations in the brain; in three of these cases there was a retention of radioactivity in the tumor. The selective necrotizing effect on the tumor cells is interpreted as mainly due to emission of Auger electrons from intracellularly accumulated 201Tl, giving rise to very high energy deposition in the vicinity of the cell nucleus. The results should also have implications for the treatment of human malignant gliomas.
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