| 1. |
- Danielsson, Anna, 1973, et al.
(författare)
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The biological effect of pentoxifylline on the survival of human head and neck cancer cells treated with continuous low and high dose-rate irradiation
- 2005
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Ingår i: J Cancer Res Clin Oncol. ; 131:7, s. 459-67
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Tidskriftsartikel (refereegranskat)abstract
- AIM: The aim of this study was to compare the radiosensitivity effect of the G2/M arrest-abrogating substance, pentoxifylline (PTX), with high dose-rate irradiation (HDRI) and low dose-rate irradiation (LDRI), during which DNA repair and cell proliferation occur. METHODS: Three squamous cell carcinoma cell lines, FaDu, RPMI 2650 and SCC-61, with differences in genomic imbalance and intrinsic radiosensitivity, were irradiated with 140 cGy/min (HDRI) and 0.7 cGy/min (LDRI) in the presence and absence of 2.0 mM PTX. The surviving fraction at 2.0 Gy (SF2) and cell-cycle phase distribution were assessed by DNA flow cytometry analysis and bromodeoxyuridine incorporation. RESULTS: With HDRI and LDRI the SF2 of FaDu cells decreased by 38.5% and 27.6%, respectively, while the corresponding figures for RPMI 2650 were 28.5% and 48.5%, and for SCC-61 were 44.2% and 28.6%. Increases in G2 populations were evident after both HDRI and LDRI of all cell lines. CONCLUSIONS: The enhancement in the cytotoxic effect of PTX was statistically significant after HDRI as well as after LDRI in all three cell lines. We therefore conclude that PTX in combination with LDRI is worth further study, both in vitro, for disclosing underlying mechanisms, and in vivo, to confirm the findings.
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| 2. |
- Gritli Linde, Amel, 1959, et al.
(författare)
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Effects of suramin on polyamine metabolism in B16 murine melanoma cells
- 1998
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Ingår i: Anticancer Res. - 0250-7005. ; 18:2A, s. 855-62
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Tidskriftsartikel (refereegranskat)abstract
- Polyamines and their biosynthetic enzymes, such as ornithine decarboxylase (ODC) and S-adenosylmethionine decarboxylase (AdoMetDC), are crucial for normal and neoplastic cell growth and differentiation. Suramin inhibits the growth of several tumor cells by affecting various intracellular targets, but its effects on polyamines are not known. In this study, the effects of suramin on some parameters of polyamine metabolism in B16 melanoma cells were investigated in vitro. Suramin increased cellular ODC activity and ODC mRNA levels, whereas the drug was directly inhibitory to the enzyme. AdoMetDC was not affected. Cellular putrescine levels were enhanced by suramin, whereas spermidine and spermine pools were unaltered. Cells cultured in the presence of suramin showed decreased cellular polyamine transport, but no direct inhibitory effect on the polyamine transporter could be found. Fluorescence spectroscopy demonstrated a direct interaction between suramin and spermine. It may be concluded that suramin affects polyamine metabolism, and that its effects in some respects are opposite to those of alpha-difluoromethylomithine (DFMO), a specific inhibitor of ODC.
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| 3. |
- Gritli Linde, Amel, 1959, et al.
(författare)
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Opposing effects of suramin and DL-alpha-difluoromethylornithine on polyamine metabolism contribute to a synergistic action on B16 melanoma cell growth in vitro
- 1998
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Ingår i: Anticancer Res. - 0250-7005. ; 18:2A, s. 863-70
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Tidskriftsartikel (refereegranskat)abstract
- Polyamines are crucial for normal and neoplastic cell growth. Treatment with the polyanionic drug suramin has pronounced antigrowth activity in several tumor cell lines, but its clinical use has been hampered by its toxicity. We have earlier shown that suramin affects cellular polyamine metabolism and transport, and that these effects were, in some respects, opposite to those of alpha-difluoromethylomithine (DFMO), a specific inhibitor to ornithine decarboxylase, a key metabolic enzyme for polyamines. DFMO has been used in anticancer trials, although with limited success. Combinations of suramin and DFMO were, hence, evaluated in vitro and were found to strongly inhibit B16 melanoma cell proliferation. DFMO alone induced melanoma cell differentiation, and suramin used in combination with DFMO did not abrogate this DFMO-induced differentiation. Synergy analysis demonstrated a pronounced growth-inhibitory synergism between suramin and DFMO. The results suggest that the efficacy of combinations of DFMO with suramin or its analogues should be further explored, especially in cells requiring high levels of polyamines for their growth.
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| 4. |
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| 5. |
- Karlsson, Elin, 1979, et al.
(författare)
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Chromosomal changes associated with clinical outcome in lymph node-negative breast cancer.
- 2007
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Ingår i: Cancer genetics and cytogenetics. - : Elsevier BV. - 0165-4608 .- 1873-4456. ; 172:2, s. 139-46
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Tidskriftsartikel (refereegranskat)abstract
- Breast cancer is the most common malignancy among women and accounts for over one million new cases worldwide per year. Lymph node-negative breast cancer patients are reputed as having a better prognosis than lymph node-positive ones. Around 20% of the lymph node-negative patients die within 10 years after diagnosis. To improve the prognostics of node-negative breast cancer, it is important to understand the underlying biologic mechanisms promoting survival, such as specific genetic changes in the tumor genome. In this study, CGH was applied to analyze 64 tumors from node-negative breast cancer patients to identify DNA copy number changes in chromosomes and chromosome regions that may be correlated to survival. The main findings show gains at 4q, 5q31 approximately qter, 6q12 approximately q16, and 12q14 approximately q22, as well as losses of 17p, 18p, and Xq, which were significantly more recurrent in tumors from deceased patients than in tumors from survivors. The average number of chromosomal changes was higher in the tumors from deceased compared to the survivor tumors. Our findings suggest that tumors with specific chromosomal aberrations at 4q, 5q31 approximately qter, 6q12 approximately q16, 12q14 approximately q22, 17p, 18p, and Xq result in an aggressive form of breast cancer and that these patients are predisposed to succumb to breast cancer.
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| 6. |
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| 7. |
- Köpf, Istvan, et al.
(författare)
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Characterization of four melanoma cell lines with electron microscopy, immunocytochemistry, cytogenetics, flow cytometry, and southern analysis.
- 1992
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Ingår i: Cancer genetics and cytogenetics. - : Elsevier BV. - 0165-4608. ; 62:2, s. 111-23
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Tidskriftsartikel (refereegranskat)abstract
- Four cell lines established from human metastatic malignant melanoma, derived from four patients, were analyzed. Ultrastructurally and immunocytochemically, the cultured tumor cells had retained characteristic features of melanocytes and of the primary malignant melanomas. The genetic stability was investigated by repeated flow-cytometric and cytogenetic analyses over 24 months of continuous cultivation. The DNA indices ranged from 1.7 to 2.1 and were stable during the entire period. The same was true for the karyotypes, which had modal numbers ranging from 50 to 84. The most common types of abnormalities were: isochromosomes i(1q), i(9q), translocations (1;17) and (3;6), and other aberrations (1p+,4p+,5p+,11p+,11q-,11q+). Abnormalities involving chromosome 1 were present in all cell lines, but loss of genetic material from chromosome 1p was demonstrated in only one of four cell lines when tested by the Southern blotting technique using a lambda MS1 probe.
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| 8. |
- Köpf, J, et al.
(författare)
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Action of interferon alpha and beta on four human melanoma cell lines in vitro.
- 1996
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Ingår i: Anticancer research. - 0250-7005. ; 16:2, s. 791-798
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Tidskriftsartikel (refereegranskat)abstract
- Four human melanoma cell lines with different copy numbers of chromosomes 9 and 21q, as studied by the G-band technique, fluorescent in situ hybridisation (FISH) and Polymerase chain reaction (PCR), were tested for their sensitivity to Interferon-alpha (IFN-alpha) and Interferon-beta (IFN-beta) in relation to dosage of interferon genes (#9) and interferon receptor genes (#21p). The two most sensitive cell lines were those containing the highest numbers of #9 per cell, while the number of #21q copies (receptor genes) seemed to have no influence on the interferon sensitivity.
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| 9. |
- Larsson, D. E., et al.
(författare)
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Chromosomal damage in two X-ray irradiated cell lines: influence of cell cycle stage and irradiation temperature
- 2007
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Ingår i: Anticancer Research. - 0250-7005 .- 1791-7530. ; 27:2, s. 749-53
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate if irradiation with X-rays in different cell cycle phases resulted in a different response as measured with the micronucleus technique. In addition, the influence of irradiation temperature was investigated. MATERIALS AND METHODS: Cells from a non-transformed human fibroblast cell line, HS2429, and a human breast cancer cell line, MCF-7, were synchronized by thymidine block and irradiated at either 2 degrees C or 37 degrees C in the G1-, S- and G2/M-phases. After cytokinesis-block by cytochalasin B, the frequency of micronuclei was determined. RESULTS: Clear dose-response relationships were found. More micronuclei were detected in fibroblast cells irradiated in G1 and S than in G2/M, while the differences were not as prominent in MCF-7 cells. The irradiation temperature had no significant influence on the formation of micronuclei in either of the cell lines. CONCLUSION: The formation of micronuclei varies with the cell cycle stage at the time of irradiation.
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| 10. |
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