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Editor’s Choice : Evidence for the Conversion of Docetaxel into 7-Epidocetaxel in Patients Receiving Conventional Taxotere® Based Chemotherapy
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Abstract: Purpose:Epimerization at the C7atom of the baccatin moiety is a common in-vitro pathway for all taxanes, including the natural precursor 10-deacetyl baccatin III and the antineoplastic drugs paclitaxel and docetaxel. To date this in-vitro epimerization of both drugs has been elucidated completely, but epimerization of docetaxel in patients during chemotherapy has not yet described. The goal of this study was to identify the epimer of docetaxel in plasma and urine of taxotere treated patients. Patients and Methods:12 patients suffering from mamma carcinoma, lung cancer or prostate cancer were treated with various docetaxel-based schedules. Blood samples were drawn before start of infusion, at the end of infusion and 20 min thereafter, urine was collected and pooled for 6 hours. Docetaxel and its epimer epidocetaxel were quantified by solid phase extraction and reversed phase HPLC. Results:In 8 of 12 patients epidocetaxel could be quantified in plasma at the end of infusion (range 0.05 – 0.54 µg/ml). 20 minutes later concentrations were below LOQ due to rapid distribution of docetaxel into tissue. In urine, epidocetaxel has been found in 7 of 12 patients (range 0.1 – 0.5 µg/ml). Conclusion: Epidocetaxel is a distinct docetaxel metabolite in man. So our knowledge, this is the first time that quantification of epidocetaxel in blood and urine of chemotherapy patients has been reported. This finding is important for designing of new docetaxel generic drugs and the development of new chemotherapeutic schedules using docetaxel. To date the in-vivo pharmacologic and toxic properties of the epimer remain unclear. Keywords: Docetaxel, epidocetaxel, epimerization, patients, plasma, urine. Download Full Article |
Editor’s Choice : Acetylation of 1,2,5,8-tetrahydroxy-9,10-anthraquinone Improves Binding to DNA and Shows Enhanced Superoxide Formation that Explains Better Cytotoxicity on JURKAT T Lymphocyte Cells
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Abstract: Background: Hydroxy-9,10-anthraquinones form the core unit of anthracycline anticancer drugs and are close structural analogues to these drugs. Although they show close resemblance to anthracyclines in physicochemical characteristics and electrochemical behavior their biophysical interactions are somewhat weaker than anthracyclines which is a disadvantage. One reason is the formation of anionic species by hydroxy-9,10-anthraquinones. Hence if formation of anionic species is prevented there could be a possibility hydroxy-9,10-anthraquinones would bind DNA better. Procedure: For this 1, 2, 5, 8-tetrahydroxy-9,10-anthraquinone (THAQ) was acetylated to obtain a tetra-acetylated derivative (THAQ-ace) whose interaction with calf thymus DNA was studied using UV-Vis spectroscopy at different pH.
Results: Binding constant values for THAQ-ace (~105) were higher than THAQ at different pH. Increase in binding constant was attributed to anionic species not formed for THAQ-ace at physiological pH. Hence, unlike THAQ, binding constant values for THAQ-ace interacting with calf thymus DNA did not show variation with pH. In fact, it remained more or less constant. Increase in size of the acetylated form (THAQ-ace) compared to THAQ had a negative influence on binding. THAQ-ace showed enhanced superoxide formation. Both DNA binding and superoxide formation were responsible for a significant improvement in anticancer activity for THAQ-ace compared to THAQ on Jurkat T lymphocyte cells.
Conclusion: Binding constant values for THAQ-ace binding to DNA were close to that reported for some standard anthracyclines. Hence, suitable modification of the less costly hydroxy-9,10-anthraquinones could provide alternatives to anthracyclines in cancer chemotherapy. Keywords: Acetylated1,2,5,8-tetrahydroxy-9,10-anthraquinone (THAQ-ace), anthracycline, calf thymus DNA, superoxide, JURKAT T lymphocyte cells. Download Full Article |
Editor’s Choice : Auto-Analysis for Ki-67 Indices of Breast Cancer Using Specified Computer Software and a Virtual Microscopy
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Abstract: Ki-67 index is one of important markers that is correlated with chemotherapy response and prognosis of breast cancer patients. However, Ki-67 index is not easily provided and are limited by intra-observer error and potentially subjective decision making. We performed this study to develop an objective auto-analysis system to count Ki-67 indices. A total of185 invasive breast cancer cases were used. Immunohistochemical staining was performed using auto-stainer and MIB-1 antibody. The results were stored digitally by virtual microscopy and auto-analyzed by Genie/Aperio software (Vista, CA, USA). As for Ki-67 indices, a good correlation was observed between direct ocular observations and auto-analysis techniques (r = 0.94, p < 0.001). The index examined by auto-analysis was significantly correlated with nuclear atypia, mitotic counts, and nuclear grade of pT1 breast cancers. Auto-analysis of 5 high power fields was better correlated with nuclear grade than that of whole fields. Further, the Ki-67 index was better correlated with mitotic counts than with nuclear atypia.Auto-analysis can provide results concordant with those obtained by direct ocular observation in a short time. Auto-analysis is more likely to result in an objective observation and provide a means by which to standardize methods for immunohistochemical Ki-67 indices of breast cancer. Keywords: Breast cancer, Ki-67, auto-analysis, virtual microscopy, immunohistochemistry, prognosis, objective analysis, nuclear grade. Download Full Article |
Editor’s Choice : Can Mutations in the BAP1 Gene be Detected by Immunohisto-chemistry in Hereditary Kidney Cancers?
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Abstract: Background: Hereditary renal cell carcinoma (RCC) constitutes about 5% of all RCCs. The most common and well studied syndromes include, VHL, HLRCC, BHD, Familial Oncocytoma, RCC Papillary Type 1, TSC, RCC associated with Succinate dehydrogenase B (SHDB) mutations and others. Several genes, including VHL, MET, FLCN, FH and genes encoding the succinate dehydrogenase (SDH) subunits B/C/D have been identified as causative. However, the genetic basis of a significant percentage of familial RCC, some with clear cell morphology remain unknown. BAP1 (BRCA1 associated protein-1), a tumor suppressor gene that encodes a nuclear deubiquitinase, is inactivated in 15% of sporadic clear cell RCCs and its loss was associated with high tumor grade and poor prognosis. In this study, we investigated the possible role of this gene in the spectrum of RCC part of hereditary syndromes. Materials and Methods: To elucidate the role of BAP1 in all the spectrum of hereditary RCC, we studied by IHC a panel of RCCs which covers the spectrum of kidney cancers and included 10 VHL tumors, 6 HLRCCs, 8 chromophobe, 5 Hereditary Papillary Type 1, 6 Oncocytomas, 3 BHD (hybrid), and 24 sporadic clear cell RCCs. To analyze the BAP1 expression in these tumors, formalin fixed paraffin embedded (FFPE) tissues were immunostained with mouse monoclonal anti-human BAP1 antibody (Clone C-4, Santa Cruz). Results: We found that all the tumors except two showed positive nuclear staining for BAP1. The two negative cases that were negative for BAP1 were Clear cell type and belonged to two siblings. Molecular analysis in a prepublished study showed both patients harboring the p.L14H mutation. Conclusion: Our study supports the hypothesis that BAP1 mutations can play a role in hereditary syndromes predominantly in clear cell tumors. Staining for BAP1 should be done when there is no definite known mutation in a clear cell cancer but the patient gives history of familial kidney cancer. The two related patients who had similar mutations had aggressive, metastatic disease, which suggests that probably BAP1 does play a role in hereditary RCC clear cell type. Keywords: Hereditary kidney cancer, BAP1, mutation, immunohistochemistry.Download Full Article |
