Enhanced Permeability of Etoposide across Everted Sacs of Rat Small Intestine by Vitamin E-TPGS

Etoposide, a widely used anticancer drug, exhibits low and variable oral bioavailability mainly because of being substrate for the efflux transporter, P-glycoprotein (P-gp). Therefore, the present study was aimed to investigate the effect of D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) and PEG 400 as P-gp inhibitors on the intestinal absorption of etoposide. Everted sacs of rat small intestine were incubated in Krebs buffer solution which contained etoposide in the absence or presence of various concentrations of TPGS or PEG 400. The effect of verapamil as a known P-gp inhibitor on the absorption of drug was also studied. The absorptive transport of etoposide was significantly enhanced (p < 0.001) in the presence of verapamil (100 μg/mL) and TPGS (over the concentration range of 0.002- 0.1 mg/mL), suggesting that the inhibition of P-gp located in the intestine may be involved in the enhancement of etoposide absorption. However, the addition of PEG 400 at various concentrations (0.05, 0.1 and 0.5% w/v) had no effect on the etoposide transport. No significant difference was found between the permeability values in the absence and presence of the maximum concentration of TPGS for two transport markers, lucifer yellow and imipramine, indicating that the enhancement in etoposide permeability in the presence of TPGS was not due to the compromise in tight junctions or membrane integrity of epithelial cells. The results of the study suggest that the use of TPGS as a safe excipient in etoposide formulations may enhance the oral bioavailability of etoposide and result in a predictable oral absorption.

Inhalational system for Etoposide liposomes: formulation development and in vitro deposition

Etoposide is a semisynthetic compound, widely used in treatment of non small cell lung cancer. However, frequent dosing and adverse effects remain a major concern in the use of etoposide. Liposomal systems for pulmonary drug delivery have been particularly attractive because of their compatibility with lung surfactant components. In the present investigation, pulmonary liposomal delivery system of etoposide was prepared by film hydration method. Various parameters were optimized with respect to entrapment efficiency as well as particle size of etoposide liposomes. For better shelf life of etoposide liposomes, freeze drying using trehalose as cryoprotectant was carried out. The liposomes were characterized for entrapment efficiency, particle size, surface topography, and in vitro drug release was carried out in simulated lung fluid at 37° at pH 7.4. The respirable or fine particle fraction was determined by using twin stage impinger. The stability study of freeze dried as well as aqueous liposomal systems was carried out at 2-8° and at ambient temperature (28±4°). The freeze dried liposomes showed better fine particle fraction and drug content over the period of six months at ambient as well as at 2-8° storage condition compared to aqueous dispersion of liposomes.

Primary small cell carcinoma of the tonsil: a case report and review of the literature

Small cell cancer (SCC) of the tonsil is a rare and aggressive cancer. There are only 10 cases of tonsillar SCC reported in the English literature. We present a case of tonsillar SCC successfully treated with induction chemotherapy using carboplatin and etoposide followed by concurrent chemoradiation therapy with cisplatin as radiosensitizer. The patient remained free of recurrence after 3 years of follow-up. We also provide a succinct review of all tonsillar SCC cases reported in the English literature and their outcomes.

PLGA nanoparticles loaded with etoposide and quercetin dihydrate individually: in vitro cell line study to ensure advantage of combination therapy

PLGA nanoparticles, separately loaded with etoposide (ETN) and quercetin dihydrate (QDN), were prepared by adapting the solvent diffusion (nanoprecipitation) technique. The effect of formulation variables such as amount of polymer, theoretical drug loading, surfactant concentration, and aqueous and organic phase volumes on particle size and entrapment efficiency, were systematically studied. The optimal formulations obtained were of submicron size (153.4 ± 4.2 nm for ETN and 148.6 ± 1.6 nm for QDN) and with low polydispersity indices (0.058 ± 0.02 for ETN and 0.088 ± 0.03 for QDN). The entrapment efficiencies were found as 63.88 ± 1.5 % and 41.36 ± 3.4 % for ETN and QDN, respectively. The characterization of ETN and QDN was done by measuring the zeta potential, TEM, and DSC analysis. The comparison was made in respect of in vitro cytotoxicity assay using cancer cell line A549 (human lung adenocarcinoma epithelial cell line). The results revealed significant increase in cytotoxicity in nanoparticle formulations than their respective free drug. The comparison was also made with respect to cytotoxic activity of individual drug and combination of drugs in the form of free drugs as well as nanoparticles. The combination treatment in the form of nanoparticles is found to produce best results among the treatments used in cytotoxicity studies.

A validated stability-indicating LC method for estimation of etoposide in bulk and optimized self-nano emulsifying formulation: Kinetics and stability effects

The present investigation was aimed to establish a validated stability-indicating liquid chromatographic method for the estimation of etoposide (ETP) in bulk drug and self-nano emulsifying formulation. ETP was successfully separated from the degradation products formed under stress conditions on LiChrospher 100 C18 reverse-phase column (a 250 mm × 4.6 mm i.d., 5-μm particle size) using 55:45 (v/v) acetonitrile-phosphate buffer saline (pH 4.5) as the mobile phase, at a flow rate of 1.0 mL min(-1) and detection at 283 nm. The response was a linear function of analyte concentration (R(2) > 0.9997) over the concentration range of 0.05-50 μg mL(-1). The method was validated for precision, accuracy, robustness, sensitivity and specificity. The % recovery of ETP at three different levels (50%, 100% and 150%) ranged between 93.84% and 100.06% in optimized self-nano emulsifying formulation, Etosid® soft-gelatin capsule and Fytosid® injection. First-order degradation kinetics of ETP were observed under acidic and alkaline conditions. The method was also applied for the stability assessment of self-nano emulsifying formulation under accelerated conditions, the formulation was found to be stable at all storage conditions with the shelf-life of 2.37 years at 25 °C. The method holds promise for routine quality control of ETP in bulk, pharmaceutical formulations as well as in stability-indicating studies.

Cytotoxic effects of human calprotectin on gastric cancer cell line is attenuated by etoposide

AIM

In this paper effect of combinational usage of calprotectin and etoposide on AGS cell line is studied.

BACKGROUND

Application of combined toxic agents such as etoposide and cicplatin are commonly used for chemotherapy purposes. As a matter of fact, calprotectin and etoposide were both applied on human gastric adenocarcinoma cell line (AGS) as antitumor agents. Both calprotectin and etoposide are topo II inhibitor. Etoposide is a lipophilic agent that can easily transport from membrane while calprotectin active intracellular pathway, probably by membrane surface receptor.

PATIENTS AND METHODS

Calprotectin was purified from human neutrophil by chromatography methods. The human gastric adenocarcinoma cell line was exposed to different concentrations and combinations of calprotectin and etoposide. MTT assay was applied for evaluation of cytotoxicity assay.

RESULTS

Viability of AGS cell line was reduced in high dosages of calprotectin and etposide. In fact, overnight incubation of these two agents together has been shown less effective than individual usage.

CONCLUSION

The result indicates that, the combination of both calprotectin and etoposide is considerably less cytotoxic on gastric cancer cells (AGS) than applying individually.

EILDV-conjugated, etoposide-loaded biodegradable polymeric micelles directing to tumor metastatic cells overexpressing α4β1 integrin

In the present study, poly(ethylene glycol)-b-poly(ε-caprolactone) micelles loaded with etoposide (ETO) were formulated and further conjugated with pentapeptide Glu-Ile-Leu-Asp-Val (EILDV) to target α4β1 integrin receptor overexpressed on metastatic tumor cell. Using a distinct ratio of carboxyl-terminated poly(ethylene glycol)-block-poly(ε-caprolactone) (HOOC-PEG-b-PCL) to methoxy-poly(ethylene glycol)-block-poly(ε-caprolactone (CH₃O-PEG-b-PCL) polymers, we formulated a series of micellar formulations having different surface densities of EILDV and observed optimum cellular uptake of micelles with 10% EILDV surface density by B16F10 cells. The cytotoxicity of EILDV-conjugated micelles was observed close to 1.5-fold higher than plain ETO after 72 h of drug incubation, demonstrating controlled release of drug inside the cell after enhanced intracellular uptake with the ability to selectively target cancer cells. In addition, EILDV-conjugated micelles inhibited the migration of B16F10 cells effectively compared with plain ETO and non-conjugated micellar formulations when cells were treated with equivalent cytotoxic concentration of the drug, i.e., IC₂₅. B16F10 cells treated with EILDV-conjugated micelles showed a significant reduction in the attachment of cells to the substrate-coated plate compared with non-conjugated micellar formulations, implying retention of the biological activity of EILDV after coupling to micelles. Furthermore, the in vivo experimental metastasis assay conducted on C57BL/6 mice demonstrated significant activity of EIDLV-conjugated micelles in the reduction of pulmonary metastatic nodule formation in both pretreatment and post-treatment methods. In conclusion, EIDLV-conjugated micelles showed higher efficacy in the treatment of metastasis and would be a promising approach in the treatment of metastasis.

Dual-Positive (CD4+/CD8+) Acute Adult T-Cell Leukemia/Lymphoma Associated with Complex Karyotype and Refractory Hypercalcemia: Case Report and Literature Review

We describe a rare case of adult T-cell leukemia characterized by an expansion of CD4+ CD8+ double-positive lymphocytes associated with human T-lymphotropic virus type 1 (HTLV-1) and a complex karyotype in a 43-year-old Caribbean male who was initially admitted to our hospital with significant lethargy, visual disturbances, dysphagia, right facial palsy and numbness in both feet for 3 days. He was found to have severe hypercalcemia (15.6 mg/dl). Peripheral blood smear showed multilobulated clover-shaped nuclei. Bone marrow and CSF flow cytometries revealed abnormal monoclonal expansion of T cells positive for CD4, CD5, CD8 and CD25 but negative for CD7, CD20, CD56, CD68 and terminal deoxynucleotidyl transferase. The polymerase chain reaction analysis showed a distinct band of the T-cell receptor γ gene, revealing T-cell clonal integration of the proviral DNA of HTLV-1, thus confirming the diagnosis of acute adult T-cell leukemia/lymphoma. Cytogenetic study revealed a male karyotype with monosomy 12, unbalanced translocation 5q and 13q and additional material on 5q, 7q, 14q and 17q. The patient underwent prednisone (EPOCH) chemotherapy followed by autologous transplantation with BEAM regimen. Although patients with a rare mixed CD4+ CD8+ immunophenotype usually present with an aggressive clinical course and have a poor prognosis, our patient was able to survive for 2.5 years.

Phase II study of combination chemotherapy with etoposide and ifosfamide in patients with heavily pretreated recurrent or persistent epithelial ovarian cancer

The aim of this trial was to investigate the efficacy and toxicity of combination chemotherapy with etoposide and ifosfamide (ETI) in the management of heavily pretreated recurrent or persistent epithelial ovarian cancer (EOC). Patients with recurrent or persistent EOC who had measurable disease and at least two prior chemotherapy participating in this phase II trial were to receive etoposide at a dose of 100 mg/m(2)/day intravenously (IV) on days 1 to 3 in combination with ifosfamide 1 g/m(2)/day IV on days 1 to 5, every 21 days. Thirty-seven patients were treated; about 78% had previously received more than two separate regimens. The response rate (RR) was 18.9% and median duration of response was 7 months (range, 1-15). Treatment free interval prior to ETI (TFI) has significant correlation with RR rate (P=0.034). Patients (n=6) with TFI > or =6 months had 50% of RR, while patients (n=31) with TFI <6 months had 12.9%. Median survival was 9 months at a median follow-up of 9.2 months. Grade 3 or 4 toxicities included neutropenia in 20.1% of the 139 cycles of ETI, anemia in 7.2% and thrombocytopenia in 8.6%. The ETI produces relatively low toxicity and modest activity in heavily pretreated recurrent or persistent EOC. This is significant in patients with TFI > or =6 months.

Establishment of VP16-resistant gastric cell line and its multi-drug resistance mechanism

AIM: To establish the VP16 resistant gastric cell line and to explore its potential multi-drug resistant mechanism.

METHODS: We used the drug concentration step-elevation method to establish VP16 resistant sub-line of gastric cell line OCUM-2M. Growth curves of cells were delineated and cell doubling times of cells were calculated using cell-counting methods. IC50 of chemotherapy drugs in two cell lines were determined by MTT methods. Cell cycle distributions were tested by FCM analysis. mRNA expression levels of caspase-3, P53, DAPK-1, DAPK-2, DAPK-3, Bcl-2, ERCC-1, MDR-1, and MRP were determined by RT-PCR.

RESULTS: OCUM-2M was a successful drug-resistant cell line, and the resistance index to VP16 was 40.53. The cell doubling time of OCUM-2M/VP16 was 30.29 ± 2.55 h, while that of parental cell line OCUM-2M was 22.96 ± 0.96 h (P < 0.01). The cross-drug-resistance of Sn38, oxaliplatin, and gemcitabine in OCUM-2M/VP16 was observed, while chemo-sensitivity of 5-FU and paclitaxol in OCUM-2M/VP16 remained the same with OCUM-2M. In OCUM-2M/VP16, the mean expression levels of apoptosis related genes, DAPK-2, DAPK-3 and Bcl-2 were respectively 0.24, 0.45, and 0.44, which were lower than OCUM-2M (0.61, 0.79 and 0.81). The expression levels of drug-resistance related genes ERCC-1 and MDR-1 in OCUM-2M/VP16 were respectively 0.84 and 0.41, which were higher than OCUM-2M (0.53 and 0.20, P < 0.01). The expression levels of caspase-3, P53, DAPK-1 and MRP had no significant change in the two cell lines.

CONCLUSION: OCUM-2M/VP16 is a successful VP16-resistant gastric cell line with cross-resistance ability, and the expression level changes of apoptosis and drug resistance related genes might contribute to drug-resistance in OCUM-2M/VP16.

PI3K/Akt/p27kip1 pathway mediates chemoresistance to Etoposide and Doxorubicin in gastric carcinoma cell line BGC-823 and its mechanism

AIM: To investigate the effect of chemo-resistance to Etoposide and Doxorubicin mediated by the PI3K/Akt/p27 pathway on human gastric carcinoma cell line BGC-823 and its mechanism.

METHODS: Cultured BGC-823 gastric cancer cells were divided into control group, PI3K/Akt/p27 Kip1 channel inhibitor Wort (Wort) group, Etoposide (Eto) group, Doxorubicin (Dox) group, Eto + Wort group and Dox + Wort group. Cell survival was assessed with MTT method. Cell cycle and apoptosis were detected using a flow cytometer (FCM). Expression level of p27 Kip1 and p27 gene mRNA was determined by Western blotting analysis and reverse transcription-polymerase chain reaction, respectively.

RESULTS: The cell survival rate at 24 h was lower in Wort group, Eto +Wort group and Dox +Wort group than in control group (57.8%, 46.5%, 44.3% vs 46.5%, 44.3%, P < 0.01). The cell ratio in G₀-G₁ phase was higher in Wort group, Eto +Wort group and Dox + Wort group than in control group (85.0 ± 3.54, 91.5 ± 3.63, 92.4 ± 3.64 vs 71.5 ± 3.25, P < 0.01) and the protein expression was increased at 12 h and 24 h. The cell survival rate in Eto and Dox groups was higher than that in control group, but no obvious change was found in G₀ - G₁ phase. The p27 mRNA expression was similar in different groups.

CONCLUSION: Activation of PI3K/Akt/p27 channel can mediate chemo-resistance to tumor cells.

Randomized, multi-center phase II trial of docetaxel plus cisplatin versus etoposide plus cisplatin as the first-line therapy for patients with advanced non-small cell lung cancer

PURPOSE

We prospectively conducted a multi-center, open-label, randomized phase II trial to compare the efficacy and safety of docetaxel plus cisplatin (DC) and etoposide plus cisplatin (EC) for treating advanced stage non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

Seventy-eight previously untreated patients with locally advanced, recurrent or metastatic NSCLC were enrolled in this study. The patients received cisplatin 75 mg/m(2) on day 1 and either docetaxel 75 mg/m(2) on day 1 or etoposide 100 mg/m(2) on days 1 to 3 in the DC or EC arm, respectively, every 3 weeks.

RESULTS

The objective response rate was 39.4% (15/38) and 18.4% (7/38) (p=0.023) in the DC and EC arms, respectively. The median time to progression (TTP) was 5.9 and 2.7 months (p=0.119), and the overall survival was 12.1 and 8.7 months (p=0.168) in the DC and EC arms, respectively. The prognostic factors for longer survival were an earlier disease stage (stage III, p=0.0095), the responders to DC (p=0.0174) and the adenocarcinoma histology (p=0.0454). The grades 3 and 4 toxicities were similar in both arms, with more febrile neutropenia (7.9% vs. 0%) and fatigue (7.9% vs. 0%) being noted in the DC arm.

CONCLUSION

DC offered a superior overall response rate than does EC, along with tolerable toxicity profiles, although the DC drug combination did not show significantly improved survival and TTP.

Treatment of Small Cell Lung Cancer

Among patients with lung cancer, approximately 15% have small cell lung cancer (SCLC), SCLC is usually staged as either limited and extensive. Extensive-stage SCLC is treated primarily with chemotherapy. A recent Japanese randomized trial compared cisplatin and irinotecan (IP) with cisplatin and etoposide (EP). Patients in the IP arm did significantly better than patients in the EP arm. In the IP arm, the response rate was 84%, and the median overall survival period was 12.8 months. Limited- stage SCLC is usually treated with concurrent chemotherapy and accelerated radiation therapy, and approximately 20% of patients are cured. Future research should focus on optimizing chemotherapy regimens and radiation therapy schedules. The role of molecular targeted drugs in the treatment of SCLC must also be evaluated.

Phase II Study of Topotecan and Etoposide as Second-line Treatment in Chemotherapy-refractory Small-cell Lung Cancer

PURPOSE

Refractory small-cell lung cancer (SCLC) has a poor prognosis, and current salvage chemotherapy for refractory SCLC, such as CAV (cyclophosphamide, adriamycin, vincristine) or topotecan, has an unsatisfactory outcome, with a response rate and overall survival of less than 10% and 6 months, respectively. This phase II study evaluated the role of topotecan combined with etoposide in SCLC patients that have progressed, or relapsed, within 3 months following completion of the initial chemotherapy.

MATERIALS AND METHODS

Twenty-seven patients were entered into this study. Eligible patients had an ECOG performance status of less than, or equal to, 2, at least one bidimensionally measurable lesion and adequate end organ function. IV topotecan, 1.0 mg/m2/d for 5 consecutive days, and etoposide, 100 mg/m2/d through days 1 to 3, were administered every 3 weeks until disease progression or undue toxicity.

RESULTS

The major toxicity was myelosuppression. Grade 3/4 anemia, granulocytopenia, and thrombocy-topenia occurred in 14.2, 34.8, and 27.3% of cycles, respectively. There was no treatment-related death, and other non-hematologic toxicities were generally mild. Four patients achieved partial responses, with a response rate RR of 14.8%. The progression-free survival PFS ranged from 1 to 7 months, with a median of 2.0 months (95% confidence interval 1.22~2.78 months). Twenty-five patients died, with a median overall survival of 5.5 months (ranging from 1 to 21 months, 95% CI 4.32~6.68 months), and the 6-month survival rate was 32.1% (95% confidence interval 14.4~49.8%).

CONCLUSION

The combination of topotecan and etoposide chemotherapy showed a modest response rate, but failed to prolong survival of refractory SCLC patients compared to topotecan monotherapy.