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Protein phosphorylation is a major mode of regulation of metabolism, gene expression and cell architecture. In chloroplasts, reversible phosphorylation of proteins is known to regulate a number of prominent processes, for instance photosynthesis, gene expression and starch metabolism. The complements of the involved chloroplast protein kinases (cpPKs) and phosphatases (cpPPs) are largely unknown, except 6 proteins (4 cpPKs and 2 cpPPs) which have been experimentally identified so far. We employed combinations of programs predicting N-terminal chloroplast transit peptides (cTPs) to identify 45 tentative cpPKs and 21 tentative cpPPs. However, test sets of 9 tentative cpPKs and 13 tentative cpPPs contain only 2 and 7 genuine cpPKs and cpPPs, respectively, based on experimental subcellular localization of their N-termini fused to the reporter protein RFP. Taken together, the set of enzymes known to be involved in the reversible phosphorylation of chloroplast proteins in A. thaliana comprises altogether now 6 cpPKs and 9 cpPPs, the function of which needs to be determined in future by functional genomics approaches. This includes the calcium-regulated PK CIPK13 which we found to be located in the chloroplast, indicating that calcium-dependent signal transduction pathways also operate in this organelle.

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The purpose of this study was to investigate the potential effects of epothilones (EPOs), a new class of microtubule stabilizing cytotoxic drugs, on glioma cells in vitro. The effects of 1, 10 and 100 nM concentrations of EPO D in four malignant human glioma cell lines were measured using a microtiter-tetrazolium assay. Besides the cell lines U87MG, U138MG and LN405, one cell line was used, which had been derived from a recurrent and therapy-resistant glioblastoma in our laboratory. In addition, changes of the cell morphology were followed by light microscopy and changes in the microtubule and actin cytoskeleton were visualized by a confocal laser microscope. In all four human glioma cell lines, 10 and 100 nM concentrations of the drug, applied for 96 h, lead to a highly significant decrease in the viable cell number (p < 0.001). A mean reduction of the viable cell number between 30% and 40% (60% and 90%) was observed for a drug concentration of 10 nM (100 nM). A round cell morphology occured in most EPO treated cells and the organized network of microtubules was shrunk in these round cells. The tubulin immunostaining now appeared amorphous and was restricted to small perinuclear regions. Large actin filaments also disappeared, but actin staining was present in the whole cytosplasm. These results prove that EPOs have antiproliferative effects in glioma cells and affect their tubulin cytoskeleton, as it was previously observed in several types of carcinoma cells.

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Because of the low number of active cytotoxic drugs and their limited activity, the evaluation of new anti-cancer agents for their activity in soft tissue sarcomas is a continuing need. The objectives of this prospective phase II trial of gemcitabine were to estimate the response rate and to define the toxicities of prolonged infusions of low-dose gemcitabine in patients with pretreated advanced soft tissue sarcomas. Patients were eligible if they had a histologic diagnosis of unresectable, recurrent or metastatic, progressive soft tissue sarcoma, and if they had been treated with at least one prior chemotherapy consisting of an anthracycline- and/or ifosfamide-containing regimen. Gemcitabine was administered as a 360 min infusion on days 1, 8 and 15 of a 28 day cycle. The initial dose of gemcitabine was 200 mg/m2 in all patients. Dose escalation to 250 mg/m2 was allowed in the case of stable disease and good tolerability of the drug. All 18 patients (median age 58 years) who enrolled were treated with gemcitabine, and all were assessable for toxicity, response and survival. Only two of these 18 patients had an objective response to a previous palliative chemotherapy. A median of 3 cycles (range 1-7) of gemcitabicin were administered. Two (11%) of the patients had a partial response lasting 5 and 6 months, respectively. Both of these patients had only lung metastases. Whereas one of these patients had a transient partial response to the foregoing chemotherapy (consisting of ifosfamide and doxorubicin), the other patient has been progressive on these drugs. One additional patient, progressive on ifosfamide and doxorubicin, had an objective response of greater than 50% confined to the lungs and stable local recurrence for 6 months. Six patients had stable disease for 3-6 months and nine patients had disease progression. The median survival was 8 months. Treatment generally was well tolerated with six patients having transient grade 3 non-hematologic toxicity, four having grade 3 neutropenia, and one having grade 4 neutropenia and thrombocytopenia. Gemcitabine, given as a prolonged infusion at a low dose level, has a favorable toxicity profile and displays antitumor activity in patients with intensively pretreated, advanced soft tissue sarcomas.

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An episode of subacute encephalopathy after the infusion of a moderate dose of methotrexate (1500 mg/m2) (MTX) is reported in a young adult with metastastic gastric cancer. Weakness of the right arm, focal seizures, lethargy and confusion appeared on day 10. High signal intensity in periventricular white matter was observed on T2-weighted magnetic resonance imaging. Symptoms resolved spontaneously and completely after 48 h. We believe that this represents an unusual case of moderate-dose MTX-induced neurotoxicity in a patient with gastric cancer, which has not previously been reported.

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During the last decades, improvements in the median survival time in patients with metastasized carcinoma of the mamma were hardly achieved. There ist still a lack of evidence that the increase in the rate of remissions due to conventional chemotherapy leads to an improvement in survival time. In 450 female patients with metastasized carcinoma of the mamma, the survival time was analyzed with the begin of the metastatic spread in relation to the treatment success of the first palliative chemotherapy. The survival time of the responder group was not significantly different to the group with a stationary tumor (p = 0.5). As patients with primary hormone therapy were included, this result changed if patients only with prognostically unfavorable characteristics (high-risk group) were selected, which received primarily and exclusively a cytostatic chemotherapy. The responder only (partial and complete responder) are profitting from the chemotherapy with a significant increase in survival time in comparison to the group with a stationary tumor (p = 0.02 and p = 0.006). Therefore, a stationary tumor in the high risk group is a result as bad as tumor progression.

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