• Journal of Pharmaceutical Investigation
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• v.38 no.4
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• pp.241-247
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• 2008

Paclitaxel is a taxane diterpene amide, which was first extracted from the stem bark of the western yew, Taxus brevifolia. This natural product has proven to be useful in the treatment of a variety of human neoplastic disorders, including ovarian cancer, breast and lung cancer. Paclitaxel is a highly hydrophobic drug that is poorly soluble in water. It is mainly given by intravenous administration. Therefore, The pharmaceutical formulation of paclitaxel ($Taxol^{(R)}$; Bristol-Myers Squibb) contains 50% $Cremophor^{(R)}$ EL and 50% dehydrated ethanol. However the ethanol/Cremophor EL vehicle required to solubilize paclitaxel in $Taxol^{(R)}$ has a pharmacological and pharmaceutical problems. To overcome these problems, new formulations for paclitaxel that do not require solubilization by $Cremophor^{(R)}$ EL are currently being developed. Therefore this study utilized a supercritical fluid antisolvent (SAS) process for cremophor-free formulation. To select hydrophilic polymers that require solubilization for paclitaxel, we evaluated polymers and the ratio of paclitaxel/polymers. HP-${\beta}$-CD was used as a hydrophilic polymer in the preparation of the paclitaxel solid dispersion. Although solubility of paclitaxel by polymers was increased, physical stability of solution after paclitaxel/polymer powder soluble in saline was unstable. To overcome this problem, we investigated the use of surfactants. At 1/20/40 of paclitaxel/hydrophilic polymer/ surfactant weight ratio, about 10 mg/mL of paclitaxel can be solubilized in this system. Compared with the solubility of paclitaxel in water ($1\;{\mu}g/mL$), the paclitaxel solid dispersion prepared by SAS process increased the solubility of paclitaxel by near 10,000 folds. The physicochemical properties was also evaluated. The particle size distribution, melting point and amophorization and shape of the powder particles were fully characterized by particle size distribution analyzer, DSC, SEM and XRD. In summary, through the SAS process, uniform nano-scale paclitaxel solid dispersion powders were obtained with excellent results compared with $Taxol^{(R)}$ for the physicochemical properties, solubility and pharmacokinetic behavior.

• BMB Reports
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• v.34 no.3
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• pp.237-243
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• 2001

Taxol, a natural product extracted from the Taxus brevifolia, is known to have significant anti-tumor activities against many common cancers, including ovarian and breast cancers. Despite the pronounced anti-tumor activity of this compound, its poor solubility in aqueous solutions hampers its clinical applications. We studied the anticancer mechanisms of the water-soluble taxol diethylenetriamine pentaacetate (DTPA) used for radiolabeling, and compared it to that of taxol. In vitro cytotoxicities of taxol and taxol-DTPA conjugate were tested in HT29 human colorectal cancer cells by the MTT method. As the result, the $IC_{50}$ value of the taxol-DTPA conjugate was about three fold higher than that of taxol. When analyzed by an agarose gel electrophoresis, the DNA ladders became evident after the incubation of cells with the taxol-DTPA conjugate for 24 h. We also found morphological changes of the cells undergoing apoptosis with electron microscopy Next, we examined the signal pathway of taxol-DTPA conjugate-induced apoptosis in HT29 cells. The activation of extracellular signal-regulated protein kinase (ERK1/2) occurred at 10, 30, 60 and 120 min after 200 nM taxol-DTPA conjugate treatment. The pretreatment of the MEK inhibitor (PD98059) completely blocked the taxol-DTPA conjugate-induced ERK1/2 activation. The activated ERK1/2 translocated into the nucleus at the same time and phosphorylated its transcriptional factor, c-Jun. These results suggest that the taxol-DTPA conjugate has an apoptotic activity in HT29 cells, and that its proapoptic activity might be related with the signal transduction via ERK1/2 and c-Jun similar to that of taxol.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.2
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• pp.95-110
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• 2006

The treatment for oral and maxillofacial carcinoma with chemotherapeutic agents is evaluated by many effective methods to reduce the tumor mass and cancer cell proliferation. However these chemotherapy have many serious side effects, such as bone marrow suppression, renal toxicity, G-I troubles. Therefore a possible approach to develop a clinically applicable chemotherapeutic agent is to screen anticancer activity of Taxol which is known to have very little side effect and have been used to breast cancer and ovarian carcinoma. Taxol is a new anti-microtubular anti-cancer agent extracted from the bark of the Pacific yew, Taxus brevifolia. Paclitaxel(Taxol) acts by promoting tubulin polymerization and over stabilizing microtubules agianst depolymerization. Despite the constant improvements of methods of the cancer treatment especially chemotherapy, the rate of cancer metastasis and recurrent are not decreased. Thus the investigation of new drug which have very little side effect and a possible clinically application continues to be a high priority. Considering that the Taxol have shown very effective chemotherapeutic agent with relatively low toxicity in many solid tumors, it deserves to evaluate its efficacy in oral squamous cell carcinoma. In this study, to investigate the in-vivo and in-vitro anti-cancer efficacy of Taxol in oral squamous cell carcinoma and lastly, the potency of Paclitaxel in the clinical application for oral cancer was evaluated. In vivo study, after HN22 cell line were xenografted in nude mice, the growth of tumor mass was observed, 3 mg/Kg taxol was injected intraperitoneally into nude mice containing tumor mass. The methods of these study were measurement of total volume of tumor mass, histopathologic study, immunohistochemical study, drug resistance assay, growth curve, MTT assay, flow cytometry, cDNA microarray in vivo and in vitro. The results were obtained as following. 1. The visual inspection of the experimental group showed that the volume of the tumor mass was slightly decreased but no significant difference with control group. 2. Ki-67 index was decreased at weeks 4 in experimental group. 3. Microscopic view of the xenografted tumor mass showed well differentiated squamous cell carcinoma and after Taxol injection, some necrotic tissue was seen weeks 4. 4. The growth curve of the tumor cells were decreased after 1day Taxol treatment. 5. According to the MTT assay, HN22 cell line showed relative drug resistancy above $5\;{\mu}g/ml$ concentrations of Taxol. 6. In drug resistance assay, the decrease of cell counts was seen relatively according to concentration. 7. In Flow cytometry, G2M phase cell arrests were seen in low concentration of the Taxol, while S phase cell arrests were seen in high concentration of the Taxol. 8. Using cDNA microarray technique, variable gene expression of ANGPTL4, TXNRD1, FAS, RRAGA, CTGF, CYCLINEA, P19, DUSP5, CEBPG, BTG1 were detacted in the oral squamous cell carcinoma cell after taxol treatment. In this study paclitaxel is effective against oral squamous cell carcinoma cell lines in vitro, but week effect was observed in vivo. So we need continuous study about anticancer effect of taxol in vivo in oral squamous cell carcinoma.

• The Journal of the Korean bone and joint tumor society
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• v.4 no.1
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• pp.13-21
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• 1998

Taxol, the extract from the Taxus brevifolia which is a Pacific yew tree has aroused the interest of the tumor investigators since the 1960s. As well, it is shown to have broad antitumor activity in preclinical experimental models. Its action mechanism is an anti-microtubule effect by duplication of tubulin. The most impressive antitumor activity of taxol has been observed in advanced ovarian cancer and metastatic breast cancer. The purpose of this study was to determine how taxol acts on malignant bone tumor cell lines, to compare its cytotoxic effect with those of other chemotherapeutic agents, and to ascertain the its combination effect with adriamycin. Cell lines used in this study were G-292(osteosarcoma, human), SaOS-2(osteosarcoma, primary, human), and HT-1080(fibrosarcoma, human). Methotrexate, adriamycin, cisplatinum, ifosfamide and taxol were used as testing chemotherapeutic agents and their maximum test concentration were $500{\mu}g/ml$, $200{\mu}g/ml$, $500{\mu}g/ml$, $1000{\mu}g/ml$, and $600{\mu}g/ml$, respectively. The media for cell culture was RPMI-1640 with 10% fetal bovine serum and gentamycin. The results were as follows. The $IC_{50}$ of methotrexate, ifosfamide, cisplatinum, adriamycin and Taxol in G-292 were $2.3{\times}10^{-1}{\mu}g/ml$, $8.0{\times}10^0{\mu}g/ml$, $3.5{\times}10^0{\mu}g/ml$, $9.8{\times}10^{-1}{\mu}g/ml$, $2.7{\times}10^{-2}{\mu}g/ml$ respectively, in SaOS-2 $3.5{\times}10^{-1}{\mu}g/ml$, $1.5{\times}10^1{\mu}g/ml$, $2.8{\times}10^0{\mu}g/ml$, $9.9{\times}10^{-2}{\mu}g/ml$, $1.0{\times}10^{-2}{\mu}g/ml$, respectively, in HT-1080 $4.2{\times}10^{-2}{\mu}g/ml$, $5.4{\times}10^1{\mu}g/ml$, $3.8{\times}10^0{\mu}g/ml$, $5.5{\times}10^{-3}{\mu}g/ml$, $1.1{\times}10^{-3}{\mu}g/ml$, respectively. In conclusion, taxol had very potent cytotoxic effect on the malignant bone tumor cell lines with adriamycin, and was more potent than methotrexate, cisplatinum and ifosfamide. There were synergistic antitumor effects on G-292 and SaOS-2 cell lines in combination test of taxol and adriamycin. From the above results, it would be estimated that taxol could be a new antitumor drug for the malignant bone tumors, providing measures against the side effects and followed by the clinical tests.