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Abstract : Caspase Pathway Activation and Reactive Oxygen Species Generation in Apoptotic Cell Death of Human Leukemic U937 and K562 Cell Line in Response to King Cobra (Ophiophagus hannah) Venom
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Abstract: Resistance and decreasing efficacy of current synthetic drug for chemotherapy of leukemic cancer draws attention for development of newer anticancer agent from natural resources. In the present study, king cobra venom (OHV) significantly inhibited leukemic cell growth in dose and time dependent manner. For U937 and K562 cell line, the IC50 dose (72 h) was found to be 4.1 µg/ml and 3.9 µg/ml respectively, observed by trypan blue exclusion method and tetrazolium bromide reduction assay. OHV treated morphometry of leukemic cell showed the characteristic features of apoptosis. Both U937 and K562 cells were arrested in the G1 phase of cell cycle with most cells exhibiting the biochemical feature of early and late apoptosis. Mitochondrial membrane potential was lost and reactive oxygen species generated highly in OHV treated leukemic cell line (U937 and K562). Western blot analysis showed OHV increased expression of Bax and decreased expression of Bcl2 in OHV treated cell as compared to untreated control U937 and K562 cell. Upregulation of Cytochrome c, Bid, Bad, Caspase 3/8/9, p21 and NF-κB down regulation of Cyclin D1, CDK4 was also showed by western blot analysis which revealed the possible pathway of OHV in cellular level. The results of this study demonstrated that OHV significantly and selectively induced leukemic cell death through both extrinsic and intrinsic apoptotic pathway. Keywords: Ophiophagus hannah, Venom, Leukemic cell, Apoptosis, Flow cytometry, Cell cycle.Download Full Article |
Abstract : 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 |
Abstract : GHK, the Human Skin Remodeling Peptide, Induces Anti-Cancer Expression of Numerous Caspase, Growth Regulatory, and DNA Repair Genes
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Abstract: GHK (glycyl-L-histidyl-L-lysine) is a human plasma copper-binding peptide that declines during aging. Numerous studies have established many biological actions of GHK: it improves tissue regeneration, possesses anti-oxidant and anti-inflammatory effects, increases cellular stemness; increases decorin, angiogenesis, and nerve outgrowth. In recent studies, GHK was found to switch gene expression from a diseased state to a healthier state for certain cancers and for chronic obstructive pulmonary disease. In studies of aggressive, metastatic human colon cancer, the Broad Institute's Connectivity Map indicated that GHK, out of 1,309 bioactive molecules studied, reversed the expression of 70% of 54 genes over-expressed genes. GHK also reactivates programmed cell death in several cultured human cancer lines. To determine GHK's potential as a cancer treatment, we analyzed the molecule's effect on the human gene expression using the Connectivity Map. GHK induces a 50% or greater change of expression in 31.2% of human genes. GHK increased gene expression in 6 of the 12 human caspase genes that activate programmed cell death. In 28 other genes, GHK altered the pattern of gene expression in a manner that would be expected to inhibit cancer growth. For DNA repair genes, there was a one-sided increase in the expression of such genes (47 UP, 5 DOWN). A previous study found that a copper peptide plus ascorbic acid inhibited Ehrlich ascites cancer in mice. Using this method with GHK-copper gave a strong suppression of Sarcoma 180 in mice. These results support the idea that GHK may help to impede or suppress cancer growth. Keywords: Copper peptides, cancer therapy, cancer inhibition, sarcoma, connectivity map. Download Full Article |
Abstract : 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 |
Abstract : Exploring Time-Resolved Characterization of the Heterogeneity and Dynamics of Ligand-Receptor Interactions on Living Cells
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Abstract: The time-resolved interaction analysis was applied on living cells to extract detailed interaction characteristics of two therapeutic antibodies and natural ligand binding to the same receptor expressed on two different human carcinoma cell lines. The observed differences in the antibody binding characteristics and heterogeneity could be attributed both to differences in antibodies and cell lines. The stability of antibody binding to EGFR on cells is significantly higher than the binding stability to isolated EGFR. This higher stability can be of fundamental importance as it potentially shifts the drug-target residence time into a domain that is limiting in pharmacokinetics and hence is of importance for in vivo drug efficacy. EGF binding to its receptor was more heterogeneous and it was demonstrated for the first time that time-resolved interaction measurements in combination with Interaction Map analysis could be used to probe the dynamics of a ligand (protein) induced dimerization and/or oligomerization process. Keywords: Cetuximab, EGF receptor, Interaction Map, kinetics, panitumumab, tracer. Download Full Article |