Reinforcing radiotherapy of gallbladder cancer with aclarubicin and neocarzinostatin.
(33/93)
Cancer of the gallbladder is radioresistant. When a 59-year-old woman was found to have an inoperable cancer of the gallbladder, she was subjected to radiotherapy combined with aclarubicin and neocarzinostatin. Therapeutic effectiveness was confirmed at autopsy as she later succumbed to uterine cervical cancer. Thus, the present radiochemotherapeutic regimen would probably provide a means of overcoming those radioresistant inoperable malignancies. (+info)
Antagonistic effect of aclarubicin on the cytotoxicity of etoposide and 4'-(9-acridinylamino)methanesulfon-m-anisidide in human small cell lung cancer cell lines and on topoisomerase II-mediated DNA cleavage.
(34/93)
The effect of combinations of the anthracycline aclarubicin and the topoisomerase II targeting drugs 4'-demethylepipodophyllotoxin-9-(4,6-O-ethylidene-beta-D-glucopyra noside) (VP-16) and 4'-(9-acridinylamino)methanesulfon-m-anisidide (m-AMSA) was investigated in a clonogenic assay. The cytotoxicity of VP-16 was almost completely antagonized by preincubating cells with nontoxic concentrations of aclarubicin. The inhibition of cytotoxicity was not seen when the cells were exposed to aclarubicin after exposure to VP-16. The inhibition was significant over a wide range of aclarubicin concentrations (3 nM to 0.4 microM), above which the toxicity of aclarubicin became apparent. A similar effect was seen on the toxicity of m-AMSA. In contrast to aclarubicin, preincubation with Adriamycin did not antagonize the effect of VP-16. With purified topoisomerase II and naked DNA, aclarubicin did not stimulate the formation of cleavable complexes between topoisomerase II and DNA. Aclarubicin concentrations above 1 microM inhibited the baseline formation of cleavable complexes elicited with the enzyme alone. Low (1 to 10 nM) aclarubicin concentrations increased the formation of cleavable complexes obtained with VP-16 and m-AMSA; however, at aclarubicin concentrations above 1 microM an antagonistic effect was obtained. In cells, the m-AMSA- and VP-16-induced, protein-concealed DNA strand breaks were completely inhibitable by aclarubicin preincubation with no synergic dose levels. Our results suggest that aclarubicin inhibits topoisomerase II-mediated DNA cleavage. This inhibition could represent the mechanism of action of the drug and explain the lack of cross-resistance to the classical anthracyclines. The observed antagonism could have consequences for scheduling of aclarubicin with topoisomerase II-active anticancer drugs. (+info)
Induction of the differentiation of WEHI-3B D+ monomyelocytic leukemia cells by inhibitors of topoisomerase II.
(35/93)
Topoisomerase II has been suggested to have a role in the early events of differentiation. This possibility was evaluated by measuring the effects of inhibitors of topoisomerase II on the induction of the differentiation of WEHI-3B D+ monomyelocytic leukemia cells. Differentiation of this cell line was induced along the granulocytic pathway by treatment with the topoisomerase II inhibitors novobiocin (150-300 microM), teniposide (20-50 nM), etoposide (0.1 microM), elsamicin (0.5 microM), and doxorubicin (40 nM). Maturation was assessed by the morphological appearance of mature forms of the granulocytic lineage, an increase in cell surface Fc receptors, the ability to reduce nitroblue tetrazolium, and the loss of proliferative capacity. In contrast, the non-topoisomerase II-reactive agent cisplatin and the topoisomerase I-reactive drug camptothecin did not cause the maturation of WEHI-3B D+ cells. Aclacinomycin A and retinoic acid, which are known efficacious inducers of the differentiation of this cell line, affected topoisomerase II extracted from WEHI-3B D+ cells in vitro, causing concentration-dependent inhibition of the strand-passing activity of the enzyme. Treatment of WEHI-3B D+ cells with novobiocin at 150 microM for 3 h or with teniposide at 50 nM for 24 h resulted in a 2- to 3-fold increase in etoposide-induced protein-DNA cross-links. Nuclear proteins in 0.35 M NaCl extracts from cells treated with novobiocin at 150 microM for 3 h or with teniposide at 50 nM for 24 h showed a slight increase in topoisomerase II activity compared to untreated cells. No changes in topoisomerase II levels, as measured by immunoblotting, were detected after treatment of WEHI-3B D+ cells with 150 microM novobiocin or 50 nM teniposide during the first 2 days of treatment. At day 3 of treatment, however, a decrease in topoisomerase II was observed in cells treated with either drug, possibly due to decreased cellular proliferation consequent to cell differentiation. The findings support the conclusion that topoisomerase II may have a role in the induction of granulocytic differentiation of WEHI-3B D+ leukemia cells. (+info)
A meta-analysis of CAG (cytarabine, aclarubicin, G-CSF) regimen for the treatment of 1029 patients with acute myeloid leukemia and myelodysplastic syndrome.
(36/93)
Gallium-67 scanning in patients with malignant pleural mesothelioma.
(38/93)
The findings of Gallium-67 scans in eleven patients with malignant pleural mesothelioma were reviewed and compared to those of chest CT findings. All patients had an abnormal thoracic Ga-67 accumulation. Six out of 11 showed a diffuse accumulation over the entire involved hemithorax and a localized uptake was shown in 5. A marked diffuse thickening of pleura in the absence of adequate gallium accumulation was observed in one patient. Two out of 11 had a reduction of gallium uptake after having combination chemotherapy. These results suggest that a diffusely increased uptake over the entire involved hemithorax is the most characteristic finding of Ga-67 scan in malignant pleural mesothelioma, and that Ga-67 scans may be helpful as a valuable indicator of the proper therapy. However, the superiority of Ga-67 scan to thoracic CT as a means of determining the extent of disease process could not be verified. (+info)
TOP2A is overexpressed and is a therapeutic target for adrenocortical carcinoma.
(39/93)