Taxol Group Research Articles

Rosmarinic acid Ameliorates neuronal regeneration in the bridging silicone rubber conduits of the sciatic nerve in taxol‐treated rats

Background and aimTaxol modulates local inflammatory conditions in peripheral nerves, which may impair their regeneration and recovery when injured. This study aimed to determine the effects of rosmarinic acid (RA, a polyphenol constituent of many culinary herbs) on the regeneration of the sciatic nerves in the bridging conduits. Experimental procedureIn the cell study, RA decreased nuclear factor (NF)-κB activity induced by taxol in a dose dependency. In the animal model, taxol-treated rats were divided into 3 groups (n = 10/group): taxol (2 mg/kg body weight for 4 times) and taxol + RA (3 times/week for 4 weeks at 20 and 40 mg/kg body weight) groups. Macrophage infiltration, calcitonin gene-related peptide (CGRP) expression levels, neuronal connectivity, animal behavior, and neuronal electrophysiology were evaluated. Results and conclusionAt the end of 4 weeks, macrophage density, CGRP expression level, and axon number significantly increased in the RA group compared with the taxol group. The RA administration unaffected heat, cold plate licking latencies, and motor coordination. Moreover, the 40 mg/kg RA group had significantly larger nerve conduction velocity and less latency compared to the taxol group. This study suggested that RA could ameliorate local inflammatory conditions to augment the recovery of regenerating nerves by accelerating their regrowth and improving electrophysiological function in taxol-treated peripheral nerve injury repaired with the silicone rubber conduit.

Esomeprazole improves the acidic microenvironment of epithelial ovarian cancer by inhibiting the expression of VATPase

Purpose: To determine the effect of esomeprazole on apoptosis of ovarian cancer cells and their sensitivity to paclitaxel, and the underlying mechanism.Methods: Human ovarian paclitaxel-resistant cancer cells were cultured in vitro, and treated with esomeprazole at doses of 50, 100 and 250 mol/L. Cell proliferation was determined using MTT assay. Paclitaxel-resistant cells were divided into control group, esomeprazole group, paclitaxel group, and esomeprazole + taxol group. Western blot was employed for the assay of protein levels of bcl-2, Bcl-xl, P-gp and V-ATPase, while BCECF-AM method was employed to determine changes in intracellular pH.Results: Esomeprazole significantly inhibited the proliferation of paclitaxel-resistant cells in a dosedependent manner. The half-maximal inhibitory concentration (IC50) value of esomeprazole + paclitaxel was significantly low, when compared with those of the other treatments (p < 0.05). Apoptosis was significantly higher in esomeprazole + paclitaxel group than in any other treatment group (p < 0.05). The expressions of Bcl-2 and P-gp in esomeprazole + paclitaxel group decreased significantly, relative to the corresponding values for other groups, while protein expression of bcl-xl was markedly increased. The intracellular pH value of esomeprazole + paclitaxel group was significantly lower than those for other treatment groups (p < 0.05).Conclusion: Esomeprazole improves the acidic microenvironment of epithelial ovarian cancer by inhibiting the expression of V-ATPase, and restores the sensitivity of ovarian cancer cells to paclitaxel by inhibiting their proliferation and apoptosis. This revelation may explain patients’ resistance topaclitaxel.
 Keywords: Esomeprazole, V-ATPase, Apoptosis, Ovarian cancer, Taxol, Sensitivity

Synergistic effect of a combination of granulocyte macrophage colony-stimulating factor and thymosin α1 on Lewis lung cancer transplanted tumor in mice

Purpose: To study the synergistic effect of a combination of granulocyte-macrophage colonystimulating factor and thymosin-α1 on the treatment of Lewis lung cancer transplanted tumor.Methods: C57BL/6 mice were used. A mouse model of Lewis lung cancer was established using Lewis lung cancer cell lines. The mice were randomly divided into blank control group, polyene taxol (DTX) group, DTX thymosin α1 (Tα-1) group, and DTX granulocyte-macrophage colony-stimulating factor (GM-CSF) group, with 8 mice per group. The degree of tumor inhibition, thymus mass, thymus index, spleen mass, spleen index, IL-6, TNF-1, IFN-1, CD4+, CD8+ T cells and the ratio of CD4+/CD8+ were determined by ELISA and flow cytometry.Results: Body mass, thymus mass, thymus index, spleen mass, spleen index, IL-6, TNF-1, IFN-1, CD4+, CD8+ T cells and the ratio of CD4+/CD8+ in DTX + Tα-1 group, DTX + GM-CSF group and DTX + Tα-1 + GM-CSF group were significantly elevated (p < 0.05), relative to the corresponding levels in DTXmice (p < 0.05). Body mass, degree of tumor inhibition, thymus mass, thymus index, spleen mass, spleen index, IL-6, TNF-1, IFN-1, CD4, CD8 T cells and CD4+/CD8+ ratio in DTX + Tα-1 + GM-CSF mice were significantly elevated, relative to the DTX + Tα-1 and DTX + GM-CSF groups (p < 0.05). Thestate of the tumor was significantly improved in the DTX + Tα-1 and DTX + GM-CSF mice.Conclusion: A combination treatment of GM-CSF, Tα-1 and DEX effectively enhances the resistance of mice and suppresses chemotherapy-induced decrease in body weight. This finding may be of clinical significance.
 Keywords: Granulocyte macrophage, Colony-stimulating factor, Thymosin, Docetaxel, Lewis lung cancer, Transplanted tumor

Low-dose paclitaxel via hyaluronan-functionalized bovine serum albumin nanoparticulate assembly for metastatic melanoma treatment.

Due to the critical role of CD44 in mediating cell adhesion and migration, CD44-targeted drug delivery via hyaluronan has been extensively explored. Herein, cationic bovine serum albumin nanoparticles were assembled with hyaluronan (HA) of various molecular weights via simple electrostatic interaction to afford hierarchical nanoparticles (HNPs) with various size distributions and structures. Next, HNPs obtained using 49 kDa HA have been used to encapsulate paclitaxel (PTX-HNPs), which demonstrated selective lung accumulation due to both size effect and CD44-mediated targetability. Biodistribution studies showed that HNPs enhanced the lung specific accumulation of HNPs in the C57BL/6 mice melanoma lung metastasis model. In the antitumor studies, compared with the Taxol or bovine serum albumin nanoparticle (NP) groups, PTX-HNPs significantly inhibited B16F10 lung metastasis at a relatively low dose. Additionally, cell migration and invasion experiments in vitro further confirmed that PTX-HNPs significantly inhibited the migration of B16F10 cells compared to Taxol or paclitaxel-loaded NP groups. Overall, our results suggest that PTX-HNPs represent a highly promising strategy for the treatment of lung metastatic melanoma.

Preparation and characterization of paclitaxel microspheres in situ gel and its antitumor efficacy by local injection

The current difficulties in the treatment of tumor include repeated administration and high recurrence rate after tumor resection. In order to reduce the number of doses, avoid side effects of chemotherapeutic drugs, suppress tumor growth and delay tumor recurrence after surgery, a temperature-sensitive in situ gel with paclitaxel microspheres (PTX/M gel) was prepared. PTX/M gel was administered by intratumoral injection once a month. First of all, paclitaxel microspheres (PTX/M) were prepared by emulsion solvent evaporation method. A laser particle size distribution analyzer was used to investigate the size, distribution, specific surface area of microspheres. Paclitaxel content was determined by high performance liquid chromatography (HPLC). Then encapsulation efficiency of paclitaxel was calculated and in vitro release characteristics were studied. Secondly, PTX/M gel was prepared by cold dissolution method. The phase transition temperature, elastic modulus, dissolution curve, correlation between dissolution and release were measured. Finally, U87 MG and 4T1 subcutaneous tumor models were established respectively to study the efficacy of PTX/M gel in suppressing tumor growth and delaying tumor recurrence after surgery. The median diameter of the selected PTX/M was (32.24±1.09) μm, the specific surface area was (206.61±10.23) m2/kg, the encapsulation efficiency was 85.29%±1.34%, and the cumulative release percentage of paclitaxel from PTX/M was 33.56%±3.33% in one month. Phase transition temperature of PTX/M gel was 33 °C. The elastic modulus of PTX/M gel at 25 °C and 37 °C were 4.2×103 Pa and 18×103 Pa, respectively. The gel could stay in the body for up to 48 hours. It could be seen from the results of animal experiments that were compared with the saline group and the Taxol group, and the tumor-bearing mice of the PTX/M gel group had the slowest tumor growth (P<0.05). Similarly, in the tumor recurrence experiments, the mice of PTX/M gel group had the latest tumor recurrence after surgery. As a local sustained-release preparation, PTX/M gel can effectively suppress tumor growth and delay postoperative recurrence of tumors. It has potential advantages in tumor treatment.

Influence of Estrogen, Bevacizumab and Other Factors on VEGF Expression in SKBR-3 Breast Cancer Cells

OBJECTIVE: To investigate expression of VEGF of SKBR-3 breast cancer cells in different estrogen and to investigate the expression of VEGF after Bevacizumab, Trastuzumab, Taxol and Insulin-like growth factor 1 receptor (IGF-1R)antibodies treatment in different estrogen. METHODS: RT-PCR was used to detect the expression of VEGF in SKBR-3 breast cancer cells under different concentrations of estrogen and VEGF monoclonal antibody, HER-2 monoclonal antibody, paclitaxel and IGF-1R antibody. At the same time, ELISA was used to detect the concentration of VEGF protein in the culture supernatant. RESULTS: The expression of VEGF in no estrogen group was 1.0618±0.0085 (VEGF/GAPDH); the expression of VEGF in low concentration group (50pg/L) was 1.0047±0.0061, the difference was statistically significant compared with the no estrogen group (P=0.002); the expression of VEGF in high concentration group (0.2 μg/mL) was 1.0868±0.0135, the difference was statistically significant compared with the no estrogen group (P<0.001). The expression of VEGF were 1.0496±0.0288 and 1.0618±0.0085 in Taxol group and contral Group (F=0.058), the expression of VEGF were 1.0884±0.0036, 1.0618 ±0.0085 in antibody of IGF-1R group and contral group (F=0.073), the expression of VEGF were 0.9887±0.0037, 1.0618±0.0085 in Trastuzumab group and contral group (F=0.075). The expression of VEGF in the paclitaxel group and the control group were 1.0496±0.0288 and 1.0618±0.0085(F=0.058);The expression of VEGF in IGF-1R group and control group were 1.0884±0.0036 and 1.0618±0.0085(F=0.073);The expression of VEGF in the trastuzumab group and the control group were 0.9887±0.0037 and 1.0618±0.0085(F=0.075); There was no significant change in the expression of VEGF in the paclitaxel group, the IGF-1R group antibody and the trastuzumab group with estrogen. The expression of VEGF in the bevacizumab group and the control group were 1.0057±0.0043 and 1.0618±0.0085( F=0.132, P=0.04), and There is no synergistic effect of estrogen and VEGF monoclonal antibody on the expression of VEGF. Conclusion: The influence of different estrogen on VEGF-expression in SKBR-3 breast cancer cells is remarkable. Taxol, antibody of IGF-1R and Trastuzumab do not change the expression of VEGF in SKBR-3 breast cancer cells, and this has no synergistic effect with estrogen.. Bevacizumab increases the expression of VEGF, and this also has no synergistic effect with estrogen.

Effects of decline of pH value on cardiomyocyte viability of rats and the mechanism

Objective: To explore the effects of decline of pH value on cardiomyocyte viability of rats, and to analyze the possible mechanism. Methods: Hearts of five newborn Sprague-Dawley rats were isolated, and then primary cardiomyocytes were cultured and used in the following experiments. (1) The primary cardiomyocytes were divided into pH 7.4+ 6 h, pH 7.0+ 6 h, pH 6.5+ 6 h, pH 6.0+ 6 h, pH 6.5+ 1 h, and pH 6.5+ 3 h groups according to the random number table, with 4 wells in each group. After being routinely cultured for 48 h (similarly hereinafter), cells in pH 7.4+ 6 h, pH 7.0+ 6 h, pH 6.5+ 6 h, and pH 6.0+ 6 h groups were cultured with pH 7.4, pH 7.0, pH 6.5, and pH 6.0 DMEM-F12 medium (similarly hereinafter), respectively, and then they were cultured for 6 h. Cells in pH 6.5+ 1 h and pH 6.5+ 3 h groups were cultured with pH 6.5 medium, and then they were cultured for 1 h and 3 h, respectively. Viability of cells was detected by methyl-thiazolyl-tetrazolium (MTT) method. (2) The primary cardiomyocytes were divided into pH 7.4, pH 6.5, and pH 6.5+ taxol groups according to the random number table, with 2 wells in each group. Cells in pH 7.4 group were cultured with pH 7.4 medium, while cells in pH 6.5 and pH 6.5+ taxol groups were cultured with pH 6.5 medium. Cells in pH 6.5+ taxol group were added with taxol of a final molarity of 0.2 μmol/L in addition, and then they were cultured for 6 h. Morphology and density of microtubule of cells was detected by immunofluorescence assay. (3) The primary cardiomyocytes were grouped and treated as in experiment (2), with 2 wells in each group. The expressions of polymerized microtubulin and free microtubulin were determined with Western blotting. (4) The primary cardiomyocytes were grouped and treated as in experiment (2), with 4 wells in each group. Viability of cells after treated with taxol was detected by MTT method. Data were processed with one-way analysis of variance and LSD-t test. Results: (1) The viability of cells in pH 7.4+ 6 h, pH 7.0+ 6 h, pH 6.5+ 6 h, pH 6.0+ 6 h, pH 6.5+ 1 h, and pH 6.5+ 3 h groups were 1.00±0.08, 0.90±0.08, 0.85±0.06, 0.83±0.04, 0.91±0.10, and 0.89±0.10, respectively. Compared with that in pH 7.4+ 6 h group, viability of cells in pH 7.0+ 6 h, pH 6.5+ 6 h, pH 6.0+ 6 h, pH 6.5+ 1 h, and pH 6.5+ 3 h groups were all decreased in different degrees (t=2.476, 4.002, 4.996, 2.168, 2.400, P<0.05). (2) Microtubules of cells in pH 7.4 group were radially distributed around the nucleus with clear tubular structure. Compared with that in pH 7.4 group, the skeleton of microtubules of cells in pH 6.5 group was obviously damaged, with broken structure of microtubule and reduced density. Compared with that in pH 6.5 group, the damage degree of microtubules of cells in pH 6.5+ taxol group was obviously alleviated, and the structure of microtubules basically returned to normal. (3) Compared with that in pH 7.4 group, the expression of free microtubulin of cells in pH 6.5 group was significantly increased (t=3.030, P<0.05), while the expression of polymerized microtubulin of cells was significantly decreased (t=8.604, P<0.05). Compared with that in pH 6.5 group, the expression of free microtubulin of cells in pH 6.5+ taxol group was significantly decreased (t=4.559, P<0.05), while the expression of polymerized microtubulin of cells was significantly increased (t=5.472, P<0.05). (4) Viability of cells in pH 7.4, pH 6.5, and pH 6.5+ taxol groups were 1.00±0.10, 0.83±0.04, and 0.93±0.10, respectively. Compared with that in pH 7.4 group, the viability of cells in pH 6.5 group was obviously declined (t=4.412, P<0.05). Compared with that in pH 6.5 group, the viability of cells in pH 6.5+ taxol group was obviously increased (t=2.461, P<0.05). Conclusions: The decline of pH value reduces the viability of cardiomyocytes of rats through destroying the skeleton of microtubule. Stabilizing microtubule skeleton can significantly reduce acidic treatment-induced damage and ameliorate cardiomyocyte viability.

Alpha1,2-fucosyl transferase gene, the key enzyme of Lewis y synthesis, promotes Taxol resistance of ovarian carcinoma through apoptosis-related proteins.

We aimed to investigate the role of FUT1 gene in Taxol resistance and to explore its mechanism in epithelial ovarian cancer. Three ovarian cancer cell lines, ES-2, SK-OV-3 and OVCAR-3 were selected from epithelial ovarian cancer in this experiment. Western blot was used to validate the protein expression level of FUT1 and the apoptosis proteins. The expression level of the corresponding carrier was validated by RT-PCR. Transfection and isolation of stable transfectants were carried out to establish the cell line models. The different concentrations of Taxol on the inhibition of cell growth rate was measured by MTT, in which Taxol resistance profiling in ovarian cancer cells was determined by IC50 data. Flow cytometry was conducted to compare cell apoptosis ability. Caspase-3 activity and the apoptosis proteins were measured by colorimetry and western blot, respectively, to further compare the cell apoptosis ability in different groups. To demonstrate the inhibition of miR-FUT1 combined with Taxol therapy against ovarian cancer, xenograft assay was carried out for the in vivo effect. The western blot results indicate that FUT1 is expressed in all of the ovarian cancer cells with different expression level: ES-2 > SK-OV-3 > OVCAR-3. Besides, FUT1 siRNA was used in the maximum expression of FUT1 cell line ES-2, or over-expression plasmid was used in the minimum expression of FUT1 cell line OVCAR-3, to establish stable expression cell lines. After the treatment with Taxol, the inhibition rate of Taxol was obviously decreased with the established cell model above, and the IC50 level was significantly increased in the FUT1 over-expression + Taxol group (p Keywords: FUT1, Lewis y, Taxol resistance, ovarian cancer, apoptosis.

Therapeutic effect of targeted Fas-expressing adenoviruses method combining γδ T cells in a mouse model of human ovarian carcinoma

The present study aimed to investigate the therapeutic effect and safety of targeted use of Fas-expressing adenoviruses combined with γδ T cell-mediated killing to treat human ovarian cancer xenografts in BALB/c mice. Shuttle plasmids containing control elements of human telomerase reverse transcriptase promoter and two-step transcriptional amplification system were constructed and packaged into adenovirus-5 vectors to generate expression of an exogenous Fas gene. A mouse xenograft model of human ovarian carcinoma was constructed. A total of 35 BALB/c mice were randomly divided into five groups, which were injected with PBS, γδ T cells, Fas-expressing adenoviruses, taxol, or Fas-expressing adenovirus and γδ T cells. The weight and volume of tumors in mice in each group was monitored. Tissue sections of the various tissues of mice in the Fas-expressing adenovirus and γδ T cells group was compared with those in the PBS group to evaluate the safety of Fas-expressing adenovirus and γδ T cells in the treatment of human ovarian cancer xenograft tumors. The results of the present study indicated that mice in all treatment groups were alive at the end of the treatment course. Tumor weight and volume was the highest in the PBS group, followed successively by the adenovirus group, the γδ T cell group, the adenovirus and γδ T cell group, and the taxol group. The weight and volume inhibition rate in adenovirus and γδ T cell group were significantly higher compared with in the PBS group (P<0.05). Pathological observation of tissue samples revealed that none of vital organs in the adenovirus and γδ T cell group developed any evident morphological changes during treatment, when compared with healthy controls. In conclusion, the combined therapy with Fas-expressing adenoviruses and γδ T cells is efficient and safe for the treatment of mouse human ovarian carcinoma xenografts.

Effects of Taxol on Regeneration in a Rat Sciatic Nerve Transection Model

Recent studies describe taxol as a candidate treatment for promoting central nerve regeneration. However, taxol has serious side effects including peripheral neurotoxicity, and little information is known about the effect of taxol on peripheral nerve regeneration. We investigated the effects of taxol on regeneration in a rat sciatic nerve transection model. Rats were divided into four groups (n = 10): normal saline (i.p.) as the control, Cremophor EL vehicle, and 2 or 6 mg/kg of taxol in the Cremophor EL solution (four times in day-2, 4, 6, and 8), respectively. We evaluated neuronal electrophysiology, animal behaviour, neuronal connectivity, macrophage infiltration, location and expression levels of calcitonin gene-related peptide (CGRP), and expression levels of both nerve growth factors and immunoregulatory factors. In the high-dose taxol group (6 mg/kg), neuronal electrophysiological function was significantly impaired. Licking latencies were significantly changed while motor coordination was unaffected. Neuronal connectivity, macrophage density, and expression levels of CGRP was dramatically reduced. Expression levels of nerve growth factors and immunoregulatory factors was also reduced, while it was increased in the low-dose taxol group (2 mg/kg). These results indicate that taxol can modulate local inflammatory conditions, impair nerve regeneration, and impede recovery of a severe peripheral nerve injury.

Vitamin E derivative-based multifunctional nanoemulsions for overcoming multidrug resistance in cancer

The multidrug resistance (MDR), including intrinsic and acquired multidrug resistance, is a major problem in tumor chemotherapy. Here, we proposed a strategy for modulating intrinsic and/or acquired multidrug resistance by altering the levels of Bax and Bcl-2 expression and inhibiting the transport function of P-gp, increasing the intracellular concentration of its substrate anticancer drugs. Vitamin E derivative-based nanoemulsions containing paclitaxel (MNEs-PTX) were fabricated in this study, and in vitro anticancer efficacy of the nanoemulsion system was evaluated in the paclitaxel-resistant human ovarian carcinoma cell line A2780/Taxol. The MNEs-PTX exhibited a remarkably enhanced antiproliferation effect on A2780/Taxol cells than free paclitaxel (PTX) (p < 0.01). Compared with that in the Taxol group, MNEs-PTX further decreased mitochondrial potential. Vitamin E derivative-based multifunctional nanoemulsion (MNEs) obviously increased intracellular accumulation of rhodamine 123 (P-gp substrate). Overexpression of Bcl-2 is generally associated with tumor drug resistance, we found that MNEs could reduce Bcl-2 protein level and increase Bax protein level. Taken together, our findings suggest that anticancer drugs associated with MNEs could play a role in the development of MDR in cancers.

Taxol prevents myocardial ischemia-reperfusion injury by inducing JNK-mediated HO-1 expression

Context: Ischemia/hypoxia and reperfusion impair mitochondria and produce a large amount of reactive oxygen species (ROS), which lead to mitochondrial and brain damage. Furthermore, heme oxygenase-1 (HO-1) as a cytoprotective gene protects cells against ROS-induced cell death in ischemia–reperfusion injury. Induction of HO-1 is involved in cytoprotective effects of taxol.Objective: We hypothesize that taxol protects cardiac myocytes possibly by preserving myocardial mitochondrial function and inducing HO-1 expression through the JNK pathway.Materials and methods: In this project, the perfused Langendorff hearts isolated from rats were randomly divided into five groups: control, ischemic, ischemic + taxol (0.1 μM), ischemic + taxol (0.3 μM), and ischemic + taxol (1 μM). Briefly, following a 15 min equilibration period, the control group was subject to normoxic perfusion for 120 min; the ischemia group, normoxic reperfusion for 120 min after 30 min ischemia; the taxol groups, normoxic reperfusion for 120 min after 30-min ischemia with taxol (0.1, 0.3, or 1 μM). The microtubule disruption score, ROS levels, and the activity of mitochondrial electron transport chain complexes I and III were examined by using immunohistochemical methods and free radical detection kits. Western blot assay was employed to study the underlying mechanisms.Results: After Taxol treatment (0.1 µM), the ischemic microtubule disruption score was reduced to 9.8 ± 1.9%. The study revealed that 0.1, 0.3, and 1 μM taxol reduced the level of ROS by 33, 46 and 51%, respectively (p < 0.05). In additional, 0.3 and 1 μM taxol dramatically increased the activity of mitochondrial electron transport chain complex I (99.11 ± 2.59, 103.49 ± 3.89) and mitochondrial electron transport chain complex III (877.82 ± 12.08; 907.42 ± 16.21; 914.73 ± 19.39, *p < 0.05). Additionally, phosphorylation levels of JNK1 were significantly increased in the taxol group. Furthermore, the expression level of HO-1 increased with taxol treatments, which could be inhibited by the specific inhibitor of JNK, SP600125.Discussion and conclusion: Taxol stabilized microtubules and effectively reduced ROS levels during ischemia. It also preserved the activity of mitochondrial complexes I and III. Interestingly, taxol induced the expression of HO-1 via the JNK pathway in cardiac myocytes.

Linear-dendritic copolymer composed of polyethylene glycol and all-trans-retinoic acid as drug delivery platform for paclitaxel against breast cancer.

A new linear-dendritic copolymer composed of poly(ethylene glycol) (PEG) and all-trans-retinoic acid (ATRA) was synthesized as the anticancer drug delivery platform (PEG-G3-RA8). It can self-assemble into core-shell micelles with a low critical micelle concentration (CMC) at 3.48 mg/L. Paclitaxel (PTX) was encapsulated into PEG-G3-RA8 to form PEG-G3-RA8/PTX micelles for breast cancer treatment. The optimized formulation had high drug loading efficacy (20% w/w of drug copolymer ratio), nanosized diameter (27.6 nm), and narrow distribution (PDI = 0.103). Compared with Taxol, PEG-G3-RA8/PTX remained highly stable in the serum-containing cell medium and exhibited 4-fold higher cellular uptake. Besides, near-infrared fluorescence (NIR) optical imaging results indicated that fluorescent probe loaded micelle had a preferential accumulation in breast tumors. Pharmacokinetics and biodistribution studies (10 mg/kg) showed the area under the plasma concentration-time curve (AUC0-∞) and mean residence time (MRT0-∞) for PEG-G3-RA8/PTX and Taxol were 12.006 ± 0.605 mg/L h, 2.264 ± 0.041 h and 15.966 ± 1.614 mg/L h, 1.726 ± 0.097 h, respectively. The tumor accumulation of PEG-G3-RA8/PTX group was 1.89-fold higher than that of Taxol group 24 h postinjection. With the advantages like efficient cellular uptake and preferential tumor accumulation, PEG-G3-RA8/PTX showed superior therapeutic efficacy on MCF-7 tumor bearing mice compared to Taxol.

Reversal of Chemoresistance in Human Lung Cancer Cell Line A549/Taxol by Synthetic Second Mitochondria-Derived Activator of Caspase Peptide

Chemoresistance is a leading cause of treatment failure in advanced lung cancer, including that with the extensively prescribed taxol. Recently, a series of structurally unique second mitochondria-derived activators of caspase (Smac) that act as antagonists of inhibitor of apoptosis proteins (IAPs) have been discovered, exhibiting the ability of inducing enhanced apoptosis of various cancer cell types when combined with chemotherapy. In the present study, we synthesized the second mitochondria-derived activator of caspase peptide (Smac-N7 for short) and explored its capacity in combination with taxol in vitro. The sensitivity assay and reversal ability of Smac-N7 were tested by MTT. Flow cytometry was used to analyze apoptosis of cells with Annexin V/PI double staining technique. Cell cloning ability was performed to reflect its biological behavior in each group. Concentrations with inhibitory rates < 10% were selected as the reversal value of Smac-N7 peptide using MTT. The reversal folds were 2.52, 3.26, 3.67, and 5.4 in taxol + Smac-N7 (0.0390625, 0.078125, 0.15625, 0.3125 μg/mL, respectively), and concentrations of Smac-N7 and reversal folds appeared in an obvious positive correlation (r(s) = 1, p = 0.000). Apoptosis analyzed at 48 hours by flow cytometry showed the apoptotic rates in taxol and 0.0390625, 0.078125, 0.15625, and 0.3125 μg/mL Smac-N7 + taxol groups were 15.4 ± 1.09%, 20.8% ± 2.18%, 28.4% ± 4.17%, 37.64% ± 6.41%, and 46.6% ± 7.76%, respectively. Concentrations of Smac-N7 appeared to have negative correlations with PE and SF (r(s) = -1, p < 0.05), which showed that the cells' cloning ability in 0.3125 μg/mL Smac-N7 + taxol group was worse than that of other groups. When combined with taxol, 0.3125 μg/mL Smac-N7 peptide may significantly increase taxol-induced apoptosis in chemoresistant A549/taxol lung cells at 48 hours, and is potentially useful as a reversal agent in lung cancer therapy.

Role of Smac in apoptosis of lung cancer cells A549 induced by Taxol.

A series of structurally unique second mitochondria-derived activators of caspase (Smac) that act as antagonists of inhibitor of apoptosis proteins (IAPs) directly have been discovered and have been shown to promote chemotherapy-induced apoptosis. In this study, we investigate the role of Smac in Taxol-induced apoptosis of lung cancer cell in vitro. PcDNA3.1/Smac recombinants were transfected into the non-small cell lung cancer cell line A549. Smac expression was detected by RT-PCR and Western blot. The invasive ability of cells was examined. Flow cytometry was used to analyze apoptosis of cells induced by Taxol with Annexin V/PI double staining technique. Smac expression was significantly higher in the PcDNA3.1/Smac recombinant group than in the untransfected group at mRNA and protein level (p < 0.05) and lower invasion through a basal membrane was apparent after transfection (p < 0.05). A small number of cells were promoted to apoptosis in the PcDNA3.1/Smac group. There were significant differences compared to the empty vector group and control group. The apoptosis rate was significantly higher in PcDNA3.1/Smac + Taxol group than in other groups (p < 0.05). Transfected Smac can enhance the chemosensitivity of the non-small cell lung cancer cell line A549 to Taxol.

Paclitaxel-loaded niosomes for intravenous administration: pharmacokineticsand tissue distribution in rats

The purpose of this study was to investigate and compare the pharmacokinetic behavior and tissue distribution of paclitaxel, delivered as commercial preparation Taxol or through Span 40 niosomes, after intravenous injection to rats.Paclitaxel-loaded Span 40 niosomes were prepared using the thin-film method. An HPLC method was developed and validated for paclitaxel determination in rat plasma and tissues.The area under the curve value of the niosome-recipient group (3.22 ± 0.255 μg h/mL) was significantly higher compared to that of the Taxol group (0.725 ± 0.163 μg h/mL). The mean residence time and the elimination half-life of paclitaxel were 1.66 ± 0.133 h and 1.15 ± 0.085 h for Taxol administration, respectively. The elimination half-life (7.63 ± 0.380 h) and the mean residence time (11.0 ± 0.6 h) of paclitaxel were significantly increased, and a pronounced delay was observed in general excretion of paclitaxel from plasma (0.0925 ± 0.00490 h(-1)) after niosomal administration. The spleen was the main tissue that accumulated paclitaxel from both niosomes and Taxol.The findings of this study show that niosomal formulation might be a useful drug delivery system for intravenous administration of paclitaxel.

Down-regulated βIII-tubulin expression can reverse paclitaxel resistance in A549/taxol cells lines

背景与目的化疗耐药导致肿瘤很快复发和/或转移, 是目前肺癌死亡的主要原因之一。β-tubulin是抗微管药物的主要细胞靶点。已有的研究证明:βⅢ-tubulin高表达与非小细胞肺癌(non-small cell lung cancer, NSCLC)耐药有关。利用RNA干扰技术沉默耐紫杉醇A549细胞(A549/Taxol)中βⅢ-tubulin基因表达, 探讨靶基因下调后对化疗药物紫杉醇的敏感性的变化以及细胞周期和细胞凋亡情况。方法构建靶向βⅢ-tubulin的siRNA, 以脂质体为载体介导βⅢ-tubulin siRNA转染A549/Taxol细胞, 利用qRT-PCR检测细胞内βⅢ-tubulin mRNA的变化情况, 并筛选出最佳干扰序列; Western blot法检测A549/Taxol细胞内βⅢ-tubulin蛋白表达的变化; MTT法检测转染后细胞株对紫杉醇敏感性的变化; 流式细胞仪检测细胞周期和细胞凋亡的变化。结果实时荧光qRT-PCR法显示转染后细胞株靶基因水平较对照组降低, 其中βⅢ-tubulin siRNA-1序列抑制率最高为(87.73±4.87)%(P < 0.01);Western blot显示转染后靶蛋白水平较对照组明显降低; MTT法表明紫杉醇处理转染后细胞株的细胞抑制率较对照组明显增加(51.77±4.60)%(P < 0.01);细胞凋亡显示βⅢ-tubulin siRNA+Taxol组细胞早期凋亡率较对照组明显增加(P < 0.01), 两者的差异有统计学意义; 细胞周期检测结果显示紫杉醇处理组的G2/M期细胞百分率高于对照组, 且转染后紫杉醇处理组的细胞晚期凋亡率较对照组增加。结论βⅢ-tubulin表达下调明显提高A549/Taxol细胞株对Taxol的敏感性。

Inhibition of Nemo-like Kinase Increases Taxol Sensitivity in Laryngeal Cancer

Several studies have shown that nemo-like kinase (NLK) plays a vital role in apoptosis of cancer cells. The present research concerned effects and mechanisms of Taxol on NLK knockdown human laryngeal cancerHep-2 cell lines in vitro. Using RNAi, methyl-thiazoltetrazolium (MTT) assays, real-time RT-PCR, Western blotting and flow cytometry analysis, growth and the cell cycle progression of NLK knockdown Hep-2 cells and expression of downstream molecules were observed. Cell growth was obviously suppressed in the Taxol treated group (P<0.001, 48 hours). Cell numbers of combined Taxol-based chemotherapy with lentivirus mediated RNAi treatment group (Lv-shNLK+Taxol goup) were significantly different from NLK-specific siRNA lentivirus infected group (Lv-shNLK group) (p<0.001). Flow cytometry analysis revealed that Lv-shNLK+Taxol caused the G0/G1-phase DNA content to decrease from 44.1 to 3.33% (p<0.001) and the S-phase DNA content to increase from 38.4 to 82.0% (p<0.001), in comparison with the Lv-shNLK+Taxol group. Immunoblot analysis showed that knockdown of NLK led to significant reduction in the levels of cyclin D1, PCNA and PARP, whereas cyclin B1 was elevated in. Cell growth was also obviously suppressed in the Hep-2 cell line, knockdown of NLK making them more sensitive to Taxol treatment. NLK is expected to become a target of new laryngeal cancer gene therapies.

IRGD Conjugated TPGS Mediates Codelivery of Paclitaxel and Survivin shRNA for the Reversal of Lung Cancer Resistance

Multidrug resistance (MDR) is one of the major obstacles in tumor treatment. Herein, we reported an active targeting strategy with peptide-mediated nanoparticles deep into tumor parenchyma, which iRGD conjugated d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) mediated codelivery of paclitaxel (PTX) and survivin shRNA (shSur) for the reversal of lung cancer resistance. Pluronic P85-polyethyleneimine/TPGS complex nanoparticles incorporated with iRGD-TPGS conjugate codelivering PTX and shSur systems (iPTPNs) could induce effective cellular uptake, RNAi effects, and cytotoxicity on A549 and A549/T cells. In particular, iPTPNs showed superiority in biodistribution, survivin expression, tumor apoptosis, and antitumor efficacy by simultaneously exerting an enhanced permeability and retention (EPR) effect and iRGD mediated active targeting effects. iPTPNs significantly enhanced the accumulation of PTX and shSur, down-regulated survivin expression, and induced cell apoptosis in tumor tissue. The in vivo antitumor efficacy showed the tumor volume of iPTPNs group (10 mg/kg) was only 12.7% of the Taxol group. Therefore, the iRGD mediated PTX and shSur codelivery system could be a very powerful approach for the reversal and therapy of lung cancer resistance.

Effect of blocking Ras signaling pathway with K-Ras siRNA on apoptosis in esophageal squamous carcinoma cells

ObjectiveTo study the effect of RNAi silencing of the K-Ras gene on Ras signal pathway activity in EC9706 esophageal cancer cells. MethodsEC9706 cells were treated in the following six groups: blank group (no transfection), negative control group (transfection no-carrier), transfection group (transfected with pSilencer-siK-ras), taxol chemotherapy group, taxol chemotherapy plus no-carrier group, taxol chemotherapy plus transfection group. Immunocytochemistry, Reverse transcription-polymerase chain reaction and western blotting were used to analyze the expression of MAPK1 (mitogen-activated protein kinases 1) and cyclin D1 in response to siRNA (small interfering RNA) transfection and taxol treatment. ResultsK-Ras (K-Ras gene) siRNA transfection of EC9706 esophageal squamous carcinoma cells decreased the expression of K-Ras, MAPK1 and cyclin D1 at the mRNA and protein level. Reverse transcription-polymerase chain reaction indicated that the expression levels of MAPK1 and cyclin D1 mRNAs were significantly lower in the transfection group than in the blank group (P<0.05). Western blotting showed that 72 h after EC9706 cell transfection, the expression levels of MAPK1 and cyclin D1 proteins had decreased in all groups, and the expression levels in the transfection group were significantly inhibited as compared with the blank group. Apoptosis increased significantly in the transfection group or after addition of taxol as compared with the blank group and the no-carrier group. The degree of apoptosis in the taxol plus transfection group was more severe. ConclusionApoptosis increased significantly in EC9706 esophageal carcinoma cells after siRNA-mediated inhibition of Ras signaling, with the most obvious increase observed in the transfection plus taxol chemotherapy group. Ras knockdown therefore increased cellular sensitivity to the chemotherapeutic agent, taxol. Ras knockdown also down-regulated the expression of the downstream genes, MAPK1 and cyclin D1, thus inhibiting the growth, proliferation and metabolism of esophageal cancer cells.