Administration Of Etoposide Research Articles

Intraventricular etoposide safety and toxicity profile in children and young adults with refractory or recurrent malignant brain tumors

Systemic administration of etoposide is effective in treating metastatic, recurrent or refractory brain tumors, but penetration into the cerebrospinal fluid is extremely poor. This study was designed to determine the safety and toxicity profile of intraventricular etoposide administration and was affiliated with the prospective, multicenter, nonblinded, nonrandomized, multi-armed HIT-REZ-97 trial. The study enrolled 68 patients, aged 1.1-34.6 (median age 11years). Adverse events that could possibly be related to intraventricular etoposide therapy were documented and analyzed. Intraventricular etoposide was simultaneously administered with either oral or intravenous chemotherapy in 426 courses according to three major schedules varying in dosing (0.25-1mg), frequency of administration (bolus injection, every 12 or 24h), course duration (5-10days) and length of interval between courses (2-5weeks). Potential treatment-related adverse effects included transient headache, seizures, infection of the reservoir, nausea and neuropsychological symptoms. Hematological side effects were not observed. One patient, with history of multiple prior therapies, who received long-term intraventricular and oral etoposide treatment developed acute myeloid leukemia as a secondary malignancy. Overall intraventricular etoposide is well tolerated. The results of this study have warranted a phase II trial to determine the effectiveness of this regimen in disease stages with very limited therapeutic options.

Quantitative Evaluation of Primordial Follicles in Rat Ovaries during the Early and Delayed Terms after Different Cytostatic Exposures.

Experiments on female Wistar rats showed that cytostatic agents (farmorubicin, platidiam, carboplatin, and etoposide) induce an initial significant decrease in the number of primordial follicles. Over the next 2-3 estrous cycles after administration of farmorubicin, platidiam, and carboplatin, this index practically did not differ from the control. The number of primordial follicles in the third and fourth estrous cycles after farmorubicin administration, as well as in the second and sixth estrous cycles after etoposide administration was much higher than the follicular reserve after cytostatic treatment (first estrous cycle). The ovarian reserve was exhausted in the delayed period after the start of the experiment. This dynamics of the pool of primordial follicles suggests that the ovary of rats in the postnatal period of life contains a limited number of female germline stem cells.

Application of FLEEOX Preoperative Chemotherapy via Intra-arterial and Intravenous Administration in Treatment of Unresectable Locally Advanced Gastric Cancer

BackgroundThe prognosis of unresectable locally advanced gastric cancer is poor. We applied preoperative chemotherapy via intra-arterial and intravenous administration to convert an initially unresectable gastric cancer to a resectable cancer. MethodsFrom January 2005 to December 2010, 105 patients with unresectable locally advanced gastric cancer (T3-4N1-3M0) were selected for preoperative chemotherapy with 5-FU + leucovorin + etoposide + oxaliplatin + epirubicin (FLEEOX) regimen. 5-Fu (370 mg/m2) and leucovorin (200 mg/m2) were administered by intravenous infusion on days 1–5. Intra-arterial administration of etoposide (80 mg/m2), oxaliplatin (80 mg/m2), and epirubicin (30 mg/m2) was performed by Seldinger method on days 6 and 20, repeated two cycles. Patients who achieved partial response (PR) or complete response (CR) underwent D2 dissection, followed by four to six cycles of XELOX chemotherapy. The response rate, 1- and 3-year survival rate, and R0 resection rate were evaluated. ResultsThe response rate of preoperative chemotherapy was 78.1 % (82 of 105 patients), with 7 cases of CR and 75 cases of PR, respectively. After chemotherapy, a total of 78 patients (74.3 %) underwent surgery, and 67 cases achieved R0 resection (85.9 %). The 1- and 3-year overall survival (OS) rate of all 105 patients was 71.9 and 31.7 % (median survival time, 18 months). The 1- and 3-year OS rate among the 78 patients treated with chemotherapy plus surgery was 84.5 and 40 % (median survival time, 30 months). Patients treated with chemotherapy plus surgery had significantly longer OS times than patients who underwent chemotherapy alone (P < 0.01). ConclusionsPatients with unresectable gastric cancer may obtain a survival benefit from preoperative chemotherapy via intra-arterial and intravenous administration and subsequent surgery.

Antimutagenicity and antigenotoxicity of Aloe arborescens Miller and Aloe barbadensis Miller in Aspergillus nidulans and Wistar rats.

Medicinal plants such as Aloe arborescens Miller and Aloe barbadensis Miller are used by the general population to treat various diseases. Therefore, the aim of this study was to evaluate the antimutagenicity of these two species using a methG1 system in Aspergillus nidulans and the comet assay in rats. The animals were treated with the plants at concentrations of 360 and 720 mg/kg body weight (1 and 2, respectively) by gavage for 14 days, followed by the administration of etoposide on treatment day 8. Blood samples were prepared for analysis of DNA damage. For the test in A. nidulans, the biA1methG1 lineage conidia were treated for 4 h with both plant species at concentrations of 4 and 8% (w/v). Then, they were washed and plated on a selective medium for frequency analysis of survival and mutation. The results of the comet assay showed that both plants were antigenotoxic compared to etoposide, which was not a typical response of methG1 systems, where only the highest concentration of plant extracts usually exhibit beneficial effects. This study demonstrates the potential antigenotoxicity and antimutagenicity of the Aloe plants tested and, therefore, supports their use as a form of preventive therapy and for health maintenance by the population.

Carboplatin and Etoposide in Heavily Pretreated Patients with Progressive High-Grade Glioma

Background: Treatment of recurrent anaplastic glioma and glioblastoma remains a particular challenge in neurooncology. The lack of controlled trials results in poor evidence for all therapeutic options. Upon recurrence, many patients are treated with bevacizumab or one of the frequently used nitrosoureas such as lomustine. However, patients who still present in overall good condition after failure of multiple lines of therapy may ask for additional therapy. Methods: Here, we report our experience with the use of carboplatin in combination with etoposide as fourth- or fifth-line therapy in patients with progressive high-grade glioma. Results: The median Karnofsky performance status at the beginning of treatment was 80%. The median progression-free survival (PFS) was 2.5 months. PFS at 6 months was 0%. Administration of carboplatin and etoposide was associated with grade 3 or 4 hematotoxicity in 8 of 12 patients. Conclusion: Carboplatin in combination with etoposide has an unfavorable risk-benefit profile in heavily pretreated glioma patients.

Etoposide pharmacokinetics impact the outcomes of lymphoma patients treated with BEAM regimen and ASCT: a multicenter study of the LYmphoma Study Association (LYSA).

Relationships between pharmacokinetic (PK) parameters of etoposide and toxicity survivals were reported in cancer patients treated at standard doses. The clinical impact of PK variations of etoposide high doses has never been explored in lymphoma patients. The primary objective of LYMPK study was to prospectively assess the impact of etoposide PK parameters on outcomes in lymphoma patients receiving high-dose chemotherapy regimen (carmustine, cytarabine, etoposide and melphalan) followed by autologous stem cell transplant (ASCT). Individual etoposide PK parameters were estimated with a previously reported bi-compartment model using NONMEM(®) program. The impact of PK parameters on toxicity and survival was assessed using univariate/multivariate analyses. A total of 91 patients with malignant lymphoma [non-Hodgkin's lymphoma (NHL): 79; Hodgkin's lymphoma: 12] at first line (n = 49) or relapse (n = 42) were enrolled in five centers. Large inter-individual variabilities in individual PK values were found for the same administration doses. In NHL patients, cumulative higher trough concentrations over the eight administrations of the first cycle (TotC min, categorized by the median 58.71 mg/L) had significant prognostic value regarding the 5-year progression-free survival (PFS: 73.6 vs 46.5 %, P = 0.015) and 5-year overall survival (OS: 74.0 vs 52.2 %, P = 0.034). Using a Cox model analysis, integrating disease settings (first line vs recurrent disease), simplified IPI and other prognostic factors, TotC min was the only significant independent prognostic factor influencing PFS, disease-specific survival and OS. This prospective study suggests survival of NHL patients treated with BEAM regimen and ASCT might be improved by increasing etoposide administration dose, or plasma concentration-based adjustment.

Regulation and function of Myb-binding protein 1A (MYBBP1A) in cellular senescence and pathogenesis of head and neck cancer

Myb-binding protein 1A (MYBBP1A) is a nucleolar protein implicated in stress response and carcinogenesis; however, its functional contribution to senescence remains elusive. In this study we show decreased MYBBP1A protein levels in tumor cells after treatment with etoposide, a potent inducer of DNA damage. Although silencing of MYBBP1A expression was not sufficient to induce senescence, it significantly increased the relative abundance of senescent cells after DNA damage. We found an inverse regulation of MYBBP1A and AKT phosphorylation (pAKT(Ser473)), which was characteristic for the pre-senescent state after etoposide administration in vitro. Tissue microarrays with tumor specimens from primary oropharyngeal squamous cell carcinoma (OPSCC) patients (n = 61) by immunohistochemistry revealed a significant correlation between MYBBP1AlowpAKT(Ser473)high staining pattern and shorter progression-free (p = 0.007) or overall survival (p < 0.001). Multivariate analysis showed that MYBBP1AlowpAKT(Ser473)high staining pattern is an independent prognosticator for OPSCC. Taken together, our study points to a critical role of MYBBP1A in the regulation of senescence under genotoxic stress and that a MYBBP1AlowAKT(Ser473)high staining pattern serves not only as a marker for the pre-senescent stage but also as an indicator of OPSCC patients at high risk for treatment failure.

Acute Kidney Injury in Adults With Hemophagocytic Lymphohistiocytosis

Acute kidney injury (AKI) in the setting of hemophagocytic lymphohistiocytosis (HLH) is poorly characterized. This study aims to describe the incidence, clinical and biological features, and outcome associated with AKI in this population. Case series. Patients with secondary HLH admitted to a single center from February 2007 through January 2013. 95 patients were included in the study. AKI. Recovery of kidney function, 6-month mortality, and complete remission of the underlying disease. AKI was defined according to the KDIGO 2012 guideline. Recovery of kidney function was defined as improvement in serum creatinine level, with return to baseline serum creatinine level ±26.5μmol/L. HLH was related to hematologic malignancy in 73 (77%), infectious disease in 21 (22%), and autoimmune disease in 9 (10%) patients and was multifactorial in 10 (11%) patients. The cause was undetermined in 2 (2%) patients. The incidence of AKI during HLH is high (62%), and 59% of the AKI population required renal replacement therapy. Main causes of AKI were acute tubular necrosis (49%), hypoperfusion (46%), tumor lysis syndrome (29%), or HLH-associated glomerulopathies (17%). At 6 months, 32% of the patients with AKI had chronic kidney disease. Two factors were associated independently with 6-month mortality by multivariable analysis: AKI stage≥ 2 (OR, 2.61; 95% CI, 1.08-6.29; P=0.03) and an underlying hematologic malignancy (OR, 3.1; 95% CI, 1.05-9.14; P=0.04). In patients with hematologic malignancy, AKI was associated with lower 6-month complete remission (non-AKI, 25%; AKI patients, 5%; P=0.05). Retrospective study, lack of histologic data. AKI in patients with HLH is frequent and adversely affects remission and survival. Early intensive management, including administration of etoposide, nephrotoxic drug withdrawal, prevention of tumor lysis syndrome, or aggressive supportive care, might improve kidney function and survival.

OP27 * ETOPOSIDE PHARMACOKINETICS FOLLOWING INTRA-CEREBROSPINAL FLUID ADMINISTRATION IN PATIENTS WITH LEPTOMENINGEAL METASTASES

INTRODUCTION: Daily intra-cerebrospinal fluid (CSF) etoposide administration regimens are in use, by-passing the blood-brain-barrier and offering higher CSF drug concentrations at 1/30th to 1/340th the dose in conventional systemically administered standard and high dose etoposide regimens, respectively. METHOD: 42 pharmacokinetic samples were obtained from a paediatric (36) and adult patient (6). Etoposide 0.75 mg was administered over 1-2 minutes via the intra-ventricular (IVT) or lumbar route (LR), on 5 consecutive days for 1-3 weeks. CSF sampling at 4h (IVT: 3, LR: 3), 8h (IVT: 3, LR: 2), 18h (IVT: 1, LR: 1), 24h (IVT: 11, LR: 9), and 72h (IVT: 5, LR: 4). Etoposide concentrations were determined by LC/MS analysis, with a detection limit of 0.1 µg/ml. RESULTS: No acute neurotoxicity was observed. Single IVT administration with LR sampling yielded higher concentrations than LR administration with IVT sampling at 4h and 8h (1.73 and 0.93 µg/ml, vs. 1.42 and 0.76 µg/ml, respectively), also observed with simultaneous LR and IVT administration (median LR concentration 5.11 and 1.77 µg/ml at 4h and 8h; median IVT concentration 3.64 and 1.48 µg/ml at 4h and 8h). Concentrations at 24h were <0.2 (median 0.15, 14 samples) and at 72h <0.1 µg/ml (8 samples), irrespective of routes and sample sites. CONCLUSION: Intra-CSF etoposide administration at this dose level is safe, with almost complete clearence at 24h, and good distribution throughout the CSF compartment, irrespective of delivery route. Higher LR compared to IVT concentrations are probably related to CSF stasis. The rapid clearance characteristic warrants investigation of continuous drug infusion to sustain targeted CSF steady state etoposide concentrations.

The SUMO-targeted ubiquitin ligase RNF4 localizes to etoposide-exposed mitotic chromosomes: Implication for a novel DNA damage response during mitosis

RNF4, a SUMO-targeted ubiquitin ligase (STUbL), localizes to the nucleus and functions in the DNA damage response during interphase of the cell cycle. RNF4 also exists in cells undergoing mitosis, where its regulation and function remain poorly understood. Here we showed that administration of etoposide, an anticancer DNA topoisomerase II poison, to mitotic human cervical cancer HeLa cells induced SUMO-2/3-dependent localization of RNF4 to chromosomes. The FK2 antibody signals, indicative of poly/multi-ubiquitin assembly, were detected on etoposide-exposed mitotic chromosomes, whereas the signals were negligible in cells depleted for RNF4 by RNA interference. This suggests that RNF4 functions as a STUbL in the etoposide-induced damage response during mitosis. Indeed, RNF4-depletion sensitized mitotic HeLa cells to etoposide and increased cells with micronuclei. These results indicate the importance of the RNF4-mediated STUbL pathway during mitosis for the maintenance of chromosome integrity and further implicate RNF4 as a target for topo II poison-based therapy for cancer patients.

The effect of quercetin on oxidative DNA damage and myelosuppression induced by etoposide in bone marrow cells of rats.

There is increasing evidence for the existence of an association between the presence of etoposide phenoxyl radicals and the development of treatment-related acute myeloid leukemia (t-AML), which occurs in a few percent of patients treated with this chemotherapeutic agent. The most common side effect caused by etoposide is myelosuppression, which limits the use of this effective drug. The goal of the study was to investigate the influence of antioxidant querectin on myelosuppression and oxidative DNA damage caused by etoposide. The influence of quercetin and/or etoposide on oxidative DNA damage was investigated in LT-12 cell line and bone marrow cells of rats via comet assay. The effect of quercetin on myelosuppression induced by etoposide was invetsigated by cytological analysis of bone marrow smears stained with May-Grünwald-Giemsa stain. Etoposide caused a significant increase in oxidative DNA damage in bone marrow cells and LT-12 cell line in comparison to the appropriate controls. Quercetin significantly reduced the oxidative DNA damage caused by etoposide both in vitro and in vivo. Quercetin also significantly protected against a decrease in the percentage of myeloid precursors and erythroid nucleated cells caused by etoposide administration in comparison to the group treated with etoposide alone. The results of the study indicate that quercetin could be considered a protectively acting compound in bone marrow cells during etoposide therapy.

Convection-enhanced delivery of etoposide is effective against murine proneural glioblastoma

Glioblastoma subtypes have been defined based on transcriptional profiling, yet personalized care based on molecular classification remains unexploited. Topoisomerase II (TOP2) contributes to the transcriptional signature of the proneural glioma subtype. Thus, we targeted TOP2 pharmacologically with etoposide in proneural glioma models. TOP2 gene expression was evaluated in mouse platelet derived growth factor (PDGF)(+)phosphatase and tensin homolog (PTEN)(-/-)p53(-/-) and PDGF(+)PTEN(-/-) proneural gliomas and cell lines, as well as human glioblastoma from The Cancer Genome Atlas. Correlation between TOP2 transcript levels and etoposide susceptibility was investigated in 139 human cancer cell lines from the Cancer Cell Line Encyclopedia public dataset and in mouse proneural glioma cell lines. Convection-enhanced delivery (CED) of etoposide was tested on cell-based PDGF(+)PTEN(-/-)p53(-/-) and retroviral-based PDGF(+)PTEN(-/-) mouse proneural glioma models. TOP2 expression was significantly higher in human proneural glioblastoma and in mouse proneural tumors at early as well as late stages of development compared with normal brain. TOP2B transcript correlated with susceptibility to etoposide in mouse proneural cell lines and in 139 human cancer cell lines from the Cancer Cell Line Encyclopedia. Intracranial etoposide CED treatment (680 μM) was well tolerated by mice and led to a significant survival benefit in the PDGF(+)PTEN(-/-)p53(-/-) glioma model. Moreover, etoposide CED treatment at 80 μM but not 4 μM led to a significant survival advantage in the PDGF(+)PTEN(-/-) glioma model. TOP2 is highly expressed in proneural gliomas, rendering its pharmacological targeting by intratumoral administration of etoposide by CED effective on murine proneural gliomas. We provide evidence supporting clinical testing of CED of etoposide with a molecular-based patient selection approach.

Involvement of PtdIns(4,5)P2 in the Regulatory Mechanism of Small Intestinal P-Glycoprotein Expression

AbstractPreviously, we reported that repeated oral administration of etoposide (ETP) activates the ezrin/radixin/moesin (ERM) scaffold proteins for P-glycoprotein (P-gp) via Ras homolog gene family member A (RhoA)/Rho-associated coiled-coil containing protein kinase (ROCK) signaling, leading to increased ileal P-gp expression. Recent studies indicate that phosphatidyl inositol 4,5-bisphosphate [PtdIns(4,5)P2] regulates the plasma-membrane localization of certain proteins, and its synthase, the type I phosphatidyl inositol 4-phosphate 5-kinase (PI4P5K), is largely controlled by RhoA/ROCK. Here, we examined whether PtdIns(4,5)P2 and PI4P5K are involved in the increased expression of ileal P-gp following the ERM activation by ETP treatment. Male ddY mice (4-week-old) were treated with ETP (10 mg/kg/day, per os, p.o.) for 5 days. Protein-expression levels were measured by either western blot or dot blot analysis and molecular interactions were assessed using immunoprecipitation assays. ETP treatment significantly increased PI4P5K, ERM, and P-gp expression in the ileal membrane. This effect was suppressed following the coadministration of ETP with rosuvastatin (a RhoA inhibitor) or fasudil (a ROCK inhibitor). Notably, the PtdIns(4,5)P2 expression in the ileal membrane, as well as both P-gp and ERM levels coimmunoprecipitated with anti-PtdIns(4,5)P2 antibody, were increased by ETP treatment. PtdIns(4,5)P2 and PI4P5K may contribute to the increase in ileal P-gp expression observed following the ETP treatment, possibly through ERM activation via the RhoA/ROCK pathway.

Pharmacokinetic Assessment of Absorptive Interaction of Oral Etoposide and Morphine in Rats

Etoposide and morphine are well known P-glycoprotein (P-gp) substrates. The pharmacokinetic effect of morphine on plasma etoposide concentration after the oral concomitant use of etoposide and morphine in rats was assessed using a population analysis approach. A P-gp substrate quinidine and the anticholinergic drug propantheline were also administered with etoposide to compare with the effects of morphine. Plasma etoposide concentration after oral administration was well described using a linear 2-compartment open model with first-order kinetic absorption from the intestine, although a flip-flop phenomenon was shown. After administration of etoposide with morphine, an increased concentration and extended time at maximum concentration were observed compared with the administration of etoposide alone. However, coadministered quinidine significantly increased the maximum concentration without changing the time of the peak concentration of etoposide. Coadministered propantheline significantly extended the time at maximum concentration, although no changes in the peak concentration of etoposide were observed. These coadministered drugs resulted in different pharmacokinetic parameters of etoposide and acted as a significant covariate. That is, morphine and quinidine significantly increased the bioavailability of etoposide believed to be due to competitive P-gp inhibition in the intestine. In contrast, morphine and propantheline decreased the absorption rate constant and were associated with the suppression of enterokinesis. These results indicate that it is necessary to understand the effects on P-gp as well as have information on other effects on the gastrointestinal tract, such as enterokinesis suppression, and to appropriately assess the pharmacokinetic interactions of the combined oral use of P-gp substrate drugs.

Changes in PtdIns(4,5)P2 induced by etoposide treatment modulates small intestinal P-glycoprotein via radixin.

Previously, we reported that repeated oral administration of etoposide (ETP) increases P-glycoprotein (P-gp) expression in association with activation of ezrin/radixin/moesin (ERM) via Ras homolog gene family member A (RhoA)/Rho-associated coiled-coil containing protein kinase (ROCK) signaling in the small intestine. However, the detailed mechanisms of this pathway have yet to be fully elucidated. Recently, phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2], one of the most abundant phosphoinositides in the plasma membrane, has attracted attention regarding its involvement in the plasma membrane localization of various membrane proteins. PtdIns(4,5)P2 is an essential factor in the dissociation and subsequent membrane translocation (activation) of ERM, and its synthetic pathway is known to be highly regulated by RhoA/ROCK signaling. Here, we examined the involvement of PtdIns(4,5)P2 in the mechanism by which ETP treatment increases small intestinal P-gp levels, and we determined which protein within ERM contributes to this phenomenon. Repeated oral treatment with ETP (10 mg/kg/d) over 5 d significantly increased PtdIns(4,5)P2 expression in the ileal membrane as measured by dot blot. Furthermore, this increase was suppressed by co-administration of a RhoA inhibitor, rosuvastatin (5 mg/kg/d, per os (p.o.)), or a ROCK inhibitor, fasudil (5 mg/kg/d, p.o.). In immunoprecipitation assays, radixin (but not ezrin or moesin) binding to PtdIns(4,5)P2 was observed to increase in association with the up-regulation of P-gp in the same fraction, and immunofluorescence studies indicated that radixin co-localized with PtdIns(4,5)P2 in the ileal tissue. In conclusion, ETP treatment appears to up-regulate PtdIns(4,5)P2 expression via RhoA/ROCK signaling, leading to the activation of ERM, presumably through the physical interaction of radixin with PtdIns(4,5)P2. This in turn increases the expression of ileal P-gp.

Prognostic Factors for Locally Advanced Cervical Cancer Treated With Neoadjuvant Intravenous and Transuterine Arterial Chemotherapy Followed by Radical Hysterectomy

The aim of this study was to identify prognostic factors associated with neoadjuvant transuterine arterial chemotherapy (TUAC) followed by type III radical hysterectomy. The medical histories of patients with stage IB2 to IIB cervical cancer who received neoadjuvant TUAC between 1996 and 2009 at our institution were retrospectively reviewed. Seventy-three patients received TUAC using cisplatin combined with intravenous nedaplatin, irinotecan, paclitaxel, or etoposide administration. Forty-seven patients (64%) had squamous cell carcinoma. The radiological response rate was 96% (95% confidence interval, 91%-100%). Radical hysterectomy was completed for 95% of enrolled patients. Examination of the resected cervical specimens showed that tumor cells were absent in 19 cases and stromal invasion was less than 3 mm in 7 cases. Among these 26 patients, 23 (32%) had pathologically negative pelvic lymph nodes and no recurrence during the follow-up period. The 5-year relapse-free survival and overall survival rates were 69% and 74%, respectively. Among 23 patients with recurrence or progressive disease, the median survival time after recurrence or progression was 12 months. In multivariate analysis, a tumor size of more than 60 mm and pathological positive lymph nodes were negative prognostic factors for overall survival. Tumor size, pathological response, and lymph node metastases were prognostic factors for cervical cancer. The high pathological response rate associated with TUAC makes it a promising treatment for bulky cervical cancer.

Expression of MDR‐transporter, ABCB5, in Merkel cell carcinoma

Merkel cell carcinoma (MCC) is a rare and aggressive cutaneous neuroendocrine neoplasm notoriously refractory to chemotherapy. We have previously found that the multidrug resistance (MDR) transporter, ABCB5, mediates drug resistance in human colonic adenocarcinoma and melanoma where it also defines stem‐like cells responsible for tumor initiation and self‐renewal. The aim of this study was to evaluate the possible role of ABCB5 in MCC. Primary and metastatic MCCs (n=74) were assessed for ABCB5, and mRNA expression and immunoreactivity was confirmed in all cases. Of note, co‐expression of ABCB5 with stem cell markers SOX2 and CD271 was documented in a subset of MCC cells in human tissue, while CD44 and ABCB5 defined separate cell populations. ABCB5+ cells were enriched in patient biopsies after chemotherapy, consistent with relative chemoresistance of this tumor cell subset. In cell line‐derived MCC xenografts in NSG mice, tumors formed by WaGa and MKL‐1 cells demonstrated increased ABCB5 expression after administration of etoposide or carboplatin. In summary, MCCs express ABCB5, and this biomarker may have functional significance regarding both chemoresistance and tumorigenic potential. NIH P50CA93683, Dermatology Foundation Career Development Award and BWH Dermatology new investigator funding.

Neonatal hemophagocytic lymphohistiocytosis associated with a vertical transmission of coxsackievirus B1

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening syndrome characterized by fever, cytopenias, hepatosplenomegaly, and coagulopathy with the background of hypercytokinemia. Early diagnosis and etoposide therapy are not established for affected newborns. An afebrile infant suffered from apnea 4 days after birth, showing leukocytosis, thrombocytopenia, coagulopathy, and cerebrospinal fluid pleocytosis. Serum levels of ferritin and sIL-2R were high. Bone marrow studies revealed activated/hemophagocytosing macrophages. Coxsackievirus B1 (CB1) was isolated from the throat and stool. Serum anti-CB1 antibody titers were elevated in the patient (4→16; 6→43days after birth) and mother (128; 10days after delivery). Normal expressions of perforin and CD107a precluded inherited HLH. The vertically transmitted CB1-HLH was successfully treated without administration of corticosteroid, cyclosporine, or etoposide. Serum cytokine levels showed dominant expression of monokines (IL-1β/6/8, and TNF-α) but not IFN-γ, which is the central player of inherited HLH. The cytokine profile might represent a unique pathophysiology of enterovirus-driven neonatal HLH.

Gene Expression Profiles in the Fetal Mouse Brain after Etoposide (VP-16) Administration

The aim of this study was to analyze the response of gene expression caused by etoposide (VP-16) in the fetal mouse brain. Four miligrams/kilogram of VP-16 was intraperitoneally injected into pregnant mice on day 12 of gestation (GD 12). Gene expression profiling of the VP-16-treated fetal mouse brain by DNA microarray was performed. The expression changes of the target genes of p53 were also examined by real-time RT-PCR. VP-16 induced S-phase accumulation, G2/M arrest, and eventually apoptosis of neuroepithelial cells in the fetal brain. DNA microarray analysis revealed that 8 of cell cycle control- and apoptosis-related genes were upregulated and that 5 of DNA damage, repair, replication, and transcription genes were also upregulated in the fetal telencephalons at 4 h after VP-16 treatment (HAT). The results of real-time RT-PCR demonstrated that the expression of topoisomerase IIα was increased at 4 and 8 HAT. The expression of pro-apoptotic factors such as puma, noxa, bax, and cyclin G was also increased from 4 to 12 HAT. These results suggest that VP-16 induces DNA damage, DNA repair, cell cycle alternation, and apoptosis in the fetal mouse brain. In addition, VP-16-induced apoptosis is mediated through the mitochondrial pathway in a p53-related manner. The present study will provide a better understanding of the mechanisms of VP-16-induced fetal brain injury.

Radixin Influences the Changes in the Small Intestinal P-Glycoprotein by Etoposide Treatment

Previously, we reported that repeated oral administration of etoposide (ETP) increases P-glycoprotein (P-gp) expression in association with activation of ezrin/radixin/moesin (ERM) in the small intestine. Radixin has recently attracted attention for its critical role in the plasma membrane localization of certain drug transporters including P-gp by working as a scaffold protein. However, there have been no report investigating that radixin really interacts with small intestinal P-gp and is involved in the mechanism by which the levels of P-gp are altered. Here, we examined whether radixin is involved in the increased P-gp expression in the small intestine after ETP treatment. Repeated oral treatment with ETP (10 mg/kg/day) for 7 d significantly increased ERM proteins bound to P-gp in the small intestine as determined by immunoprecipitation analysis. In particular, radixin but not ezrin or moesin bound to P-gp was dramatically increased in association with the up-regulation of P-gp in the small intestinal membrane, and radixin was highly co-localized with P-gp as measured by immunofluorescence analysis. In conclusion, radixin may contribute, at least in part, to an increase in the expression of the small intestinal P-gp upon induction with repeated oral treatment with ETP.