Role of electrochemotherapy in the treatment of metastatic melanoma and other metastatic and primary skin tumors

Electroporation is a novel therapeutic modality that uses pulsed electrical currents to enhance the uptake of drugs, vaccines and genes into cells, and has been used for over 20 years. Electroporation therapy using cytotoxic drugs is called electrochemotherapy. Electrochemotherapy has been studied in vitro, in vivo and in clinical trials. It is potentially useful for treating patients with metastatic tumors, such as melanoma, and even select primary tumors, such as head and neck squamous cell carcinomas and basal cell carcinoma. Various chemotherapeutic agents have been tested with electroporation therapy, but bleomycin and cisplatin are the two most widely used. The biological basis of electroporation therapy is outlined in this review and basic science studies and the limited clinical studies that have involved electrochemotherapy are reviewed. Particular focus is placed on trials involving melanoma, head and neck cancers and other primary and metastatic skin cancers.

[Determining the relative content of cisplatin in cells by acridine orange fluorescence intensity]

The fluorescence intensity of acridine orange (AO) dye bound to living human leukocytes, rat leukocytes, and Pliss lymphosarcoma cells of rat has been studied by fluorescence microscopy. The cell suspension of each test was divided into two parts, to one of which the drug cisplatin was added to a final concentration of 0.1 μg/mL and the mixture was incubated for 20 - 60 min. Acridine orange was then added and the average intensity of red and green fluorescence of cells was determined. The brightness of AO in the green region of the spectrum was reduced approximately 3-fold (p = 0.001) in cells with cisplatin. In the red region of the fluorescence, differences in the brightness of cells with and without cisplatin were not observed. These data indicate that a decrease in the brightness of green fluorescence of AO can be a test for the presence of cisplatin in cells.

Duration of cisplatin excretion in breast milk

Cisplatin, a platinum-based chemotherapy agent, is commonly used in treating cancers that may affect women of childbearing age, including cervical cancer, triple-negative breast cancer, and pediatric tumors in adolescents. The authors found that platinum was undetectable in breast milk at 66 hours and beyond following a 70-mg dose of intravenous cisplatin. Relative infant dose of platinum was calculated to be between 0.29% and 0.40% of the maternal dose corrected for body weight. This case demonstrates minimal exposure to platinum via breast milk, following a single 70-mg intravenous dose of cisplatin.

Phase III study of afatinib or cisplatin plus pemetrexed in patients with metastatic lung adenocarcinoma with EGFR mutations

PURPOSE

The LUX-Lung 3 study investigated the efficacy of chemotherapy compared with afatinib, a selective, orally bioavailable ErbB family blocker that irreversibly blocks signaling from epidermal growth factor receptor (EGFR/ErbB1), human epidermal growth factor receptor 2 (HER2/ErbB2), and ErbB4 and has wide-spectrum preclinical activity against EGFR mutations. A phase II study of afatinib in EGFR mutation-positive lung adenocarcinoma demonstrated high response rates and progression-free survival (PFS).

PATIENTS AND METHODS

In this phase III study, eligible patients with stage IIIB/IV lung adenocarcinoma were screened for EGFR mutations. Mutation-positive patients were stratified by mutation type (exon 19 deletion, L858R, or other) and race (Asian or non-Asian) before two-to-one random assignment to 40 mg afatinib per day or up to six cycles of cisplatin plus pemetrexed chemotherapy at standard doses every 21 days. The primary end point was PFS by independent review. Secondary end points included tumor response, overall survival, adverse events, and patient-reported outcomes (PROs).

RESULTS

A total of 1,269 patients were screened, and 345 were randomly assigned to treatment. Median PFS was 11.1 months for afatinib and 6.9 months for chemotherapy (hazard ratio [HR], 0.58; 95% CI, 0.43 to 0.78; P = .001). Median PFS among those with exon 19 deletions and L858R EGFR mutations (n = 308) was 13.6 months for afatinib and 6.9 months for chemotherapy (HR, 0.47; 95% CI, 0.34 to 0.65; P = .001). The most common treatment-related adverse events were diarrhea, rash/acne, and stomatitis for afatinib and nausea, fatigue, and decreased appetite for chemotherapy. PROs favored afatinib, with better control of cough, dyspnea, and pain.

CONCLUSION

Afatinib is associated with prolongation of PFS when compared with standard doublet chemotherapy in patients with advanced lung adenocarcinoma and EGFR mutations.

Efficacy of cisplatin and Lipoplatin™ in combined treatment with radiation of a colorectal tumor in nude mouse

BACKGROUND

Optimal conditions for efficient concomitant chemoradiation treatment of colorectal cancer with cisplatin still need to be better defined. In addition, intolerance of healthy tissue to cisplatin prevents the full exploitation of its radiosensitizing potential. A liposomal formulation of cisplatin, Lipoplatin™, was proposed to overcome its toxicity. Using an animal model of colorectal cancer, we determined the platinum window, defined by studying the pharmacokinetics and time-dependent intracellular distribution of cisplatin and Lipoplatin™.

MATERIALS AND METHODS

In nude mice bearing HCT116 human colorectal carcinoma treated with cisplatin or Lipoplatin™, the platinum accumulation in blood, serum, different normal tissues, tumor and different tumor cell compartments was measured by inductively coupled plasma mass spectrometry. Radiation treatment (15 Gy) was given 4, 24, and 48 h after drug administration and was correlated to the amount of platinum-DNA adducts in the cancer cells. The resulting tumor growth delay is reported and correlated to apoptosis analysis.

RESULTS

The greatest effects and highest apoptosis were observed when radiation was given at 4 h or 48 h after drug injection. These times correspond to the times of maximal platinum binding to tumor DNA. An enhancement factor (ratio of group treated by combined treatment compared to chemotherapy alone) of 13.00 was obtained with Lipoplatin™, and 4.09 for cisplatin when tumor irradiation was performed 48 h after drug administration.

CONCLUSION

The most efficient combination treatment of radiation with cisplatin or Lipoplatin™ was observed when binding of platinum to DNA was highest. These results improve our understanding over the mechanisms of platinum-induced radiosensitization and should have significant impact on the design of more efficient treatment protocols.

Shell crosslinked knedel-like nanoparticles for delivery of cisplatin: effects of crosslinking

Polymeric micelles and shell crosslinked knedel-like (SCK) nanoparticles were loaded with up to 48% (w/w) cisplatin. These spherical cisplatin-loaded nanoparticles displayed sustained platinum release over 5 days in PBS, enhanced stability over free cisplatin in aqueous milieu, and significant antitumor activity in vitro against two cancer cell lines.

Constancy in Integrated Cisplatin Plasma Concentrations Among Pediatric Patients

The authors report on the variability in the integrated quantity of free (unbound) plasma cisplatin (area under curve of plasma concentration versus time, AUC). The AUC was measured in 19 patients receiving cisplatin doses proportional to body surface areas (BSA), 30 mg/m2 over 1 hour. The relative standard deviation (RSD, population standard deviation divided by mean value) for the maximum free plasma cisplatin concentration (Cmax, microM) was 0.338; for the half-life (t1/2, minute), 0.210; and for the AUC (microM minute), 0.320. Thus, BSA-based dosing gave significant variability in the AUC. We attempted to use (weight)a(height)b, seeking values of a and b that gave the smallest RSD in AUC, but only minimal improvement could be obtained by deviating from the BSA formula (a=b=0.5). However, dosing proportional to (weight)d(Cmax)f (with d approximately 3/4 and f approximately -1) reduced the RSD in AUC from approximately 1/3 to approximately 1/10. Dosing proportional to (weight)m (Cmax)n(t1/2)p (with m approximately 0.7, n approximately -1, and p approximately -1/2) reduced it further, to approximately 1/32. In contrast, using (weight)d(Cmax)f(age)g gave no improvement over (weight)d(Cmax)f. The authors conclude that the inconsistency in AUC can be reduced 10-fold with dosing proportional to the weight and the drug pharmacokinetic parameters [(weight0.7)/(Cmaxxt1/2(0.5))].

Adaptive and innovative Radiation Treatment FOR improving Cancer treatment outcomE (ARTFORCE); a randomized controlled phase II trial for individualized treatment of head and neck cancer

BACKGROUND

Failure of locoregional control is the main cause of recurrence in advanced head and neck cancer. This multi-center trial aims to improve outcome in two ways. Firstly, by redistribution of the radiation dose to the metabolically most FDG-PET avid part of the tumour. Hereby, a biologically more effective dose distribution might be achieved while simultaneously sparing normal tissues. Secondly, by improving patient selection. Both cisplatin and Epidermal Growth Factor Receptor (EGFR) antibodies like Cetuximab in combination with Radiotherapy (RT) are effective in enhancing tumour response. However, it is unknown which patients will benefit from either agent in combination with irradiation. We will analyze the predictive value of biological markers and (89)Zr-Cetuximab uptake for treatment outcome of chemoradiation with Cetuximab or cisplatin to improve patient selection.

METHODS

ARTFORCE is a randomized phase II trial for 268 patients with a factorial 2 by 2 design: cisplatin versus Cetuximab and standard RT versus redistributed RT. Cisplatin is dosed weekly 40 mg/m(2) for 6 weeks. Cetuximab is dosed 250 mg/m(2) weekly (loading dose 400 mg/m(2)) for 6 weeks. The standard RT regimen consists of elective RT up to 54.25 Gy with a simultaneous integrated boost (SIB) to 70 Gy in 35 fractions in 6 weeks. Redistributed adaptive RT consists of elective RT up to 54.25 Gy with a SIB between 64-80 Gy in 35 fractions in 6 weeks with redistributed dose to the gross tumour volume (GTV) and clinical target volume (CTV), and adaptation of treatment for anatomical changes in the third week of treatment.Patients with locally advanced, biopsy confirmed squamous cell carcinoma of the oropharynx, oral cavity or hypopharynx are eligible.Primary endpoints are: locoregional recurrence free survival at 2 years, correlation of the median (89)Zr-cetuximab uptake and biological markers with treatment specific outcome, and toxicity. Secondary endpoints are quality of life, swallowing function preservation, progression free and overall survival.

DISCUSSION

The objective of the ARTFORCE Head and Neck trial is to determine the predictive value of biological markers and (89)Zr-Cetuximab uptake, as it is unknown how to select patients for the appropriate concurrent agent. Also we will determine if adaptive RT and dose redistribution improve locoregional control without increasing toxicity.ClinicalTrials.gov Identifier: NCT01504815.

Development of pH-sensitive pectinate/alginate microspheres for colon drug delivery

The purposes of this study were to develop and evaluate calcium pectinate/alginate microspheres (PAMs) and to exploit their pH-sensitive properties for colon-targeted delivery of encapsulated cisplatin. PAMs were prepared using an electrospraying method. The PAMs, as cores, were then coated with Eudragit S100 using a polyelectrolyte multilayer coating technique in aqueous solution. The morphology of the microspheres was observed under scanning electron microscopy. In vitro drug release studies were performed in simulated gastrointestinal fluid, and the results indicated that approximately 5 % of the cisplatin was released from the Eudragit S100-coated PAMs, and 51 % of the cisplatin was released from the uncoated PAMs at 1 h. The release of cisplatin from the Eudragit S100-coated PAMs was more sustained in simulated gastric fluid than in simulated intestinal fluid due to the increased solubility of the coating polymer in media with pH >7.0. Drug release from the Eudragit S100-coated PAMs was best described by the Higuchi's square root model. From these results, it was concluded that Eudragit S100-coated PAMs are a potential carrier for delivery of cisplatin to the colon.

Antigenotoxic properties of chlorophyll b against cisplatin-induced DNA damage and its relationship with distribution of platinum and magnesium in vivo

The chemotherapeutic agent cisplatin (cDDP) is widely used to treat a variety of solid and hematological tumors. However, cDDP exerts severe side effects, such as nephrotoxicity, neurotoxicity, and bone-marrow suppression. The use of some dietary compounds to protect organs that are not targets in association with chemotherapy has been encouraged. This study evaluated the protective effects of chlorophyll b (CLb) on DNA damage induced by cDDP by use of single-cell gel electrophoresis (SCGE) assays. Further, this investigation also determined platinum (Pt) and magnesium (Mg) bioaccumulation in mice tissues after treatment with CLb alone and/or in association of cDDP (simultaneous treatment) by inductively coupled plasma-mass spectroscopy (ICP-MS). All parameters were studied in peripheral blood cells (PBC), kidneys, and liver of mice after administration of CLb (0.2 or 0.5 mg/kg of body weight [b.w.]), cDDP (6 mg/kg b.w.), and the combination CLb 0.2 plus cDDP or CLb 0.5 plus cDDP. Pt accumulation in liver and kidneys was higher than that found in PBC, while DNA damage was higher in kidneys and liver than in PBC. Further, treatment with CLb alone did not induce DNA damage. Evidence indicates that genotoxic effects produced by cDDP may not be related to Pt accumulation and distribution. In combined treatments, CLb decreased DNA damage in tissues, but the PT contents did not change and these treatments also showed that CLb may be an important source of Mg. Thus, our results indicate that consumption of CLb-rich foods may diminish the adverse health effects induced by cDDP exposure.

Selective induction of glutathione S-transferases in round spermatids from the Brown-Norway rat by the chemotherapeutic regimen for testicular cancer

Chemotherapeutic drugs can affect DNA in male germ cells, thereby impacting on the integrity of the genome transmitted to offspring. Drug metabolizing enzymes can protect cells from xenobiotic insult. We analyzed the expression pattern of such enzymes in isolated round spermatids from rats exposed to drugs used to treat testicular cancer: bleomycin, etoposide, and cisplatin (BEP). The number of isozymes expressed and the overall relative expression values were highest for the glutathione S-transferases (GSTs). Moreover, BEP treatment significantly increased the expression of 8 GSTs and 3 aldehyde dehydrogenases. Increased expression of GST isozymes was confirmed by qRT-PCR and Western blot analysis. Although Gst genes can be targets for epigenetic modifications, promoter DNA methylation was not affected by BEP treatment. As GSTs are involved in drug resistance mechanisms, we hypothesize that BEP induction of GST expression may lead to the survival of damaged germ cells and the production of abnormal sperm.

Preparation, biodistribution and neurotoxicity of liposomal cisplatin following convection enhanced delivery in normal and F98 glioma bearing rats

The purpose of this study was to evaluate two novel liposomal formulations of cisplatin as potential therapeutic agents for treatment of the F98 rat glioma. The first was a commercially produced agent, Lipoplatin™, which currently is in a Phase III clinical trial for treatment of non-small cell lung cancer (NSCLC). The second, produced in our laboratory, was based on the ability of cisplatin to form coordination complexes with lipid cholesteryl hemisuccinate (CHEMS). The in vitro tumoricidal activity of the former previously has been described in detail by other investigators. The CHEMS liposomal formulation had a Pt loading efficiency of 25% and showed more potent in vitro cytotoxicity against F98 glioma cells than free cisplatin at 24 h. In vivo CHEMS liposomes showed high retention at 24 h after intracerebral (i.c.) convection enhanced delivery (CED) to F98 glioma bearing rats. Neurotoxicologic studies were carried out in non-tumor bearing Fischer rats following i.c. CED of Lipoplatin™ or CHEMS liposomes or their "hollow" counterparts. Unexpectedly, Lipoplatin™ was highly neurotoxic when given i.c. by CED and resulted in death immediately following or within a few days after administration. Similarly "hollow" Lipoplatin™ liposomes showed similar neurotoxicity indicating that this was due to the liposomes themselves rather than the cisplatin. This was particularly surprising since Lipoplatin™ has been well tolerated when administered intravenously. In contrast, CHEMS liposomes and their "hollow" counterparts were clinically well tolerated. However, a variety of dose dependent neuropathologic changes from none to severe were seen at either 10 or 14 d following their administration. These findings suggest that further refinements in the design and formulation of cisplatin containing liposomes will be required before they can be administered i.c. by CED for the treatment of brain tumors and that a formulation that may be safe when given systemically may be highly neurotoxic when administered directly into the brain.

Detoxifying antitumoral drugs via nanoconjugation: the case of gold nanoparticles and cisplatin

Nanoparticles (NPs) have emerged as a potential tool to improve cancer treatment. Among the proposed uses in imaging and therapy, their use as a drug delivery scaffold has been extensively highlighted. However, there are still some controversial points which need a deeper understanding before clinical application can occur. Here the use of gold nanoparticles (AuNPs) to detoxify the antitumoral agent cisplatin, linked to a nanoparticle via a pH-sensitive coordination bond for endosomal release, is presented. The NP conjugate design has important effects on pharmacokinetics, conjugate evolution and biodistribution and results in an absence of observed toxicity. Besides, AuNPs present unique opportunities as drug delivery scaffolds due to their size and surface tunability. Here we show that cisplatin-induced toxicity is clearly reduced without affecting the therapeutic benefits in mice models. The NPs not only act as carriers, but also protect the drug from deactivation by plasma proteins until conjugates are internalized in cells and cisplatin is released. Additionally, the possibility to track the drug (Pt) and vehicle (Au) separately as a function of organ and time enables a better understanding of how nanocarriers are processed by the organism.

Platinum concentration in sentinel lymph nodes after preoperative intra-arterial cisplatin chemotherapy targeting primary tongue cancer

CONCLUSION

We conclude that intra-arterially injected cisplatin passed via lymph flow into sentinel nodes (SNs) as the platinum concentration in the SNs was higher than that in the non-sentinel nodes (NSNs). It is possible that preoperative intra-arterial chemotherapy targeting primary cancer also has a therapeutic effect on subclinical metastatic SNs.

OBJECTIVES

Intra-arterial chemoradiotherapy has been reported to be effective against not only primary tumors but also nodal metastases. We considered the hypothesis that intra-arterially injected cisplatin passed via lymph flow into regional nodes. This study aimed to investigate intra-arterially injected cisplatin distribution to regional nodes by comparing platinum concentrations in SNs and NSNs.

METHODS

Five patients with T1-2 N0 tongue cancer were treated with preoperative intra-arterial chemotherapy (cisplatin, 100 mg/m(2)) targeting primary cancer. Partial glossectomy together with SN biopsy and elective neck dissection were performed 2 weeks after intra-arterial chemotherapy. Platinum concentrations in the lymph nodes were measured using a Zeeman atomic absorption spectrometer.

RESULTS

Thirteen SNs were harvested together with eight NSNs from the areas adjacent to the SNs. Platinum concentrations were then measured, revealing a significant difference in platinum concentration between the SNs and the NSNs (mean ± SD, 0.682 ± 0.246 µg/g vs 0.506 ± 0.274 µg/g; p = 0.049).

Phase I study of miriplatin combined with transarterial chemotherapy using CDDP powder in patients with hepatocellular carcinoma

BACKGROUND

There is no standard therapeutic procedure for the hepatocellular carcinoma (HCC) in patients with poor hepatic reserve function. With the approval of newly developed chemotherapeutic agent of miriplatin, we have firstly conducted the phase I study of CDDP powder (DDP-H) and miriplatin combination therapy and reported its safety and efficacy for treating unresectable HCC in such cases. To determine the maximum tolerated dose (MTD) and dose-limiting toxicity (DLT) for the combination of transarterial oily chemoembolization (TOCE) and transarterial chemotherapy (TAC) using miriplatin and DDP-H for treating unresectable hepatocellular carcinoma (HCC).

METHODS

Transarterial chemotherapy using DDP-H was performed through the proper hepatic artery targeting the HCC nodules by increasing the dose of DDP-H (35-65 mg/m(2)) followed by targeting the HCC nodules by transarterial oily chemoembolization with miriplatin.

RESULTS

A total of nine patients were enrolled in this study and no DLT was observed with any dose of DDP-H in all cases in whom 80 mg (median, 18-120) miriplatin was administered. An anti-tumour efficacy rating for partial response was obtained in one patient, while a total of four patients (among eight evaluated) showed stable disease response, leading to 62.5% of disease control rate. The pharmacokinetic results showed no further increase in plasma platinum concentration following miriplatin administration.

CONCLUSION

Our results suggest that a combination of DDP-H and miriplatin can be safely administered up to their respective MTD for treating HCC.

TRIAL REGISTRATION

This study was registered with the University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR000003541).

Comparative evaluation of small-molecule chemosensitizers in reversal of cisplatin resistance in ovarian cancer cells

Cisplatin-resistance is one of the major challenges in the treatment of epithelial ovarian cancer. Small-molecule chemosensitizers provide a therapeutically feasible approach to overcome cisplatin resistance in ovarian cancer. However, proper selection of chemosensitizer is of prime importance owing to phenotypic differences in cisplatin-resistant ovarian cancers. The resistance reversal activity of chemosensitizers buthionine sulfoximine (BSO), triethylenetetramine (TETA), genistein, rapamycin and colchicine was investigated in various cisplatin-resistant ovarian cancer cells, 2008 C13, CP70 and OVCAR 8 using MTT assays. Cellular accumulation of cisplatin in the presence of chemosensitizers was analyzed by inductively-coupled plasma-mass spectroscopy (ICP-MS). Chemosensitizers exhibited resistance reversal activity in 2008 C13 and CP70 cells in the following order; colchicine> genistein>TETA> rapamycin ≥ BSO (p<0.05), which is in correlation with cellular accumulation of cisplatin. In conclusion, our study demonstrates that resistance reversal activity of chemosensitizers varies with phenotypic behavior of cisplatin-resistant ovarian cancer cells. Data from our study can be utilized to choose a specific chemosensitizer for individualized combination therapy for cisplatin-resistant ovarian cancer.

Gold nanoparticles conjugated with cisplatin/doxorubicin/capecitabine lower the chemoresistance of hepatocellular carcinoma-derived cancer cells

BACKGROUND AND AIMS

The aim of the current study was to evaluate in vitro the anti-tumor efficacy of gold nanoparticles (GNPs) conjugated with conventional chemotherapy drugs for the treatment of liver cancer. This approach based on gold proposes a novel platform therapy with minimal toxicity and increased efficacy profiles for the destruction of hepatic cancer cells.

METHODS

GNPs, stabilized with a monolayer of L-aspartate and additional cytostatic drugs, were successfully used as a complex tumor-targeting drug-delivery system. The drugs (doxorubicin, cisplatin, and capecitabine) were non-covalently conjugated onto the hydrophilic assemblies of GNPs-L-Aspartate nanostructure. Transmission electron microscopy was used to characterize the morphological and structural properties of these drug-metallic nanostructures.

RESULTS

The cellular proliferation rates in the presence of the anti-cancer drugs delivered by the GNPs were found to be statistically lower than those of cells exposed to the cytostatic drugs alone, indicating that GNPs facilitated an increased susceptibility of cancer cells to cisplatin, doxorubicin, and capecitabine plus ribavirin.

CONCLUSION

This approach could offer a new chemotherapy strategy for patients diagnosed with unresectable hepatocellular carcinoma (HCC).

Intralymphatic delivery of platinum-based chemotherapeutics is possible: an experimental study

PURPOSE

Systemic chemotherapy regimens with cisplatinum have been associated with several toxicities. Thus, a loco-regional therapy approach may greatly reduce the toxicity. For this purpose, we designed this experimental study to investigate whether local chemotherapeutic injection is superior to systemic cisplatinum injection for retroperitoneal lymph nodes.

METHODS

A total of 48 male Wistar rats were included to the study. Rats were divided into six groups. In the first three groups, systemic applications of cisplatinum, carboplatinum and oxaliplatin were performed, respectively. In the last three, local administration of cisplatinum, carboplatinum and oxaliplatin was performed, respectively. One hour after the chemotherapeutic agent applications, retroperitoneal lymph nodes were dissected and platinum concentrations were analyzed.

RESULTS

When compared with systemic route, achieving higher platinum concentrations in the local chemotherapeutic application groups was the most spectacular result of the study. Serum platinum concentrations were also lower in the local application groups than systemic ones. When we compared local and systemic applications between three chemotherapeutic agents, the most significant concentration difference was seen in carboplatinum group.

CONCLUSION

The results of this study demonstrate that intralymphatic delivery of cisplatinum, carboplatinum and oxaliplatin leads to higher drug concentrations in the retroperitoneal lymph nodes when compared with intravenous administration.

NOXA-induced alterations in the Bax/Smac axis enhance sensitivity of ovarian cancer cells to cisplatin

Ovarian cancer is the most common cause of death from gynecologic malignancy. Deregulation of p53 and/or p73-associated apoptotic pathways contribute to the platinum-based resistance in ovarian cancer. NOXA, a pro-apoptotic BH3-only protein, is identified as a transcription target of p53 and/or p73. In this study, we found that genetic variants of Bcl-2 proteins exist among cisplatin-sensitive and -resistant ovarian cancer cells, and the responses of NOXA and Bax to cisplatin are regulated mainly by p53. We further evaluated the effect of NOXA on cisplatin. NOXA induced apoptosis and sensitized A2780s and SKOV3 cells to cisplatin in vitro and in vivo. The effects were mediated by elevated Bax expression, enhanced caspase activation, release of Cyt C and Smac into the cytosol. Furthermore, gene silencing of Bax or Smac significantly attenuated NOXA and/or cisplatin-induced apoptosis in chemosensitive A2780s cells, whereas overexpression of Bax or addition of Smac-N7 peptide significantly increased NOXA and/or cisplatin-induced apoptosis in chemoresistant SKOV3 cells. To our knowledge, these data suggest a new mechanism by which NOXA chemosensitized ovarian cancer cells to cisplatin by inducing alterations in the Bax/Smac axis. Taken together, our findings show that NOXA is potentially useful as a chemosensitizer in ovarian cancer therapy.

Imaging tumor-stroma interactions during chemotherapy reveals contributions of the microenvironment to resistance

Little is known about the dynamics of cancer cell death in response to therapy in the tumor microenvironment. Intravital microscopy of chemotherapy-treated mouse mammary carcinomas allowed us to follow drug distribution, cell death, and tumor-stroma interactions. We observed associations between vascular leakage and response to doxorubicin, including improved response in matrix metalloproteinase-9 null mice that had increased vascular leakage. Furthermore, we observed CCR2-dependent infiltration of myeloid cells after treatment and that Ccr2 null host mice responded better to treatment with doxorubicin or cisplatin. These data show that the microenvironment contributes critically to drug response via regulation of vascular permeability and innate immune cell infiltration. Thus, live imaging can be used to gain insights into drug responses in situ.

[Structure-functional organization of eukaryotic high-affinity copper importer CTR1 determines its ability to transport copper, silver and cisplatin]

It was shown recently, that high affinity Cu(I) importer eukaryotic protein CTR1 can also transport in vitro abiogenic Ag(I) ions and anticancer drug cisplatin. At present there is no rational explanation how CTR1 can transfer platinum group, which is different by coordination properties from highly similar Cu(I) and Ag(I). To understand this phenomenon we analyzed 25 sequences of chordate CTR1 proteins, and found out conserved patterns of organization of N-terminal extracellular part of CTR1 which correspond to initial metal binding. Extracellular copper-binding motifs were qualified by their coordination properties. It was shown that relative position of Met- and His-rich copper-binding motifs in CTR1 predisposes the extracellular CTR1 part to binding of copper, silver and cisplatin. Relation between tissue-specific expression of CTR1 gene, steady-state copper concentration, and silver and platinum accumulation in organs of mice in vivo was analyzed. Significant positive but incomplete correlation exists between these variables. Basing on structural and functional peculiarities of N-terminal part of CTR1 a hypothesis of coupled transport of copper and cisplatin has been suggested, which avoids the disagreement between CTR1-mediated cisplatin transport in vitro, and irreversible binding of platinum to Met-rich peptides.

[Ototoxicity of cisplatin]

The objective of this publication is to summarize "classical" and modern concepts of pathogenesis, clinical features of cisplatin ototoxicity, its screening, and prophylaxis. It is argued that pathogenesis of a cisplatin-induced injury to the inner ear shares common features with the ototoxic mechanisms of action of other pharmaceuticals even though it is characterized by certain important differences. The authors consider the mechanisms of ototropicity, specific cytochemical aspects of cisplatin cytotoxicity that aggravate risk factors, and genetic predisposition to the development of iatrogenic problems. The data are presented on monitoring and experimental aspects of otoprotection for the prevention of cisplatin-induced damage to the auditory analyzer.

[Impact of different methods of estimating renal function on determining eligibility for cisplatin (CDDP)-based chemotherapy in patients with invasive urothelial carcinoma]

Assessment of renal function is important to determine the appropriate dose for cisplatin (CDDP)-based chemotherapy. Many previous CDDP-based chemotherapy trials for bladder cancer have required a creatinine-clearance (Ccr) ≧60 ml/min for entry. However, there is little evidence on renal function assessed by estimated glomerular filtration rate (eGFR) using the 4-variable Modification of Diet in Renal Disease Study Equation (MDRD), which has recently been introduced, to determine the eligibility for CDDP-based chemotherapy. To evaluate the proportion of patients with invasive urothelial carcinoma(UC) who would be ineligible ("unfit") to receive CDDP-based chemotherapy based on eGFR criteria (eGFR ＜60 ml/min/1.73 m2), and to determine the side effects of chemotherapy in these "unfit" patients, we conducted a retrospective clinical study. Our study population consisted of 61 consecutive patients who underwent 100% dose CDDP-based chemotherapy for invasive UC with 24 h-Ccr≧50 ml/min between June 2001 and July 2009. We assessed renal function using 3 equations (eGFR, Ccr according to Cockcroft-Gault formula (C-G Ccr), and Ccr examined by 24-hour urine collection (24 h-Ccr)) as well. Mean values of eGFR, C-G Ccr, and 24 h-Ccr were 58.6, 68.9, and 82.8 ml/min, respectively (P＜ 0.001). In total, 29/61(48%) patients were ineligible ("unfit") to receive chemotherapy based on eGFR criteria. However, there was no difference in the frequency of side effects between eGFR ≧60 ml/min/ 1.73 m2 and eGFR ＜60 ml/min/1.73 m2 groups. Our observations suggest that 24 h-Ccr≧50 ml/min would be a reasonable cutoff for CDDP-based chemotherapy even when eGFR ＜60 ml/min/1.73 m2.

Pharmacokinetic analysis of capecitabine and cisplatin in combination with trastuzumab in Japanese patients with advanced HER2-positive gastric cancer

PURPOSE

To evaluate the pharmacokinetics (PK) of capecitabine and cisplatin, administered in combination with or without trastuzumab, in Japanese patients with HER2-positive advanced gastric cancer (AGC).

METHODS

Patients eligible for this PK study (study JP19959), which was carried out during treatment Cycle 1 of the ToGA study, received either capecitabine and cisplatin (XP arm) or trastuzumab plus capecitabine and cisplatin (HXP arm). All patients received capecitabine (1,000 mg/m(2) orally, twice daily for 14 days) and cisplatin (80 mg/m(2) intravenous infusion on Day 1). Patients in the HXP arm also received trastuzumab (8 mg/kg intravenous infusion on Day 1), concurrently with capecitabine. No further study medication was administered during study JP19959. Serial plasma samples for PK analysis were obtained at intervals before and after the administration of capecitabine and cisplatin on Day 1.

RESULTS

Twenty-two patients were enrolled in this PK study: eight in the HXP arm and 14 in the XP arm. All blood samples were available for PK analysis. Co-administration of trastuzumab resulted in no statistically or clinically significant changes in the PK profiles of capecitabine or its metabolites, or of cisplatin (total or unbound platinum).

CONCLUSIONS

Variability in the AUC(last) and C (max) values for the capecitabine was consistent with the known PK profile of capecitabine and fell within established limits. Concurrent trastuzumab therapy is unlikely to alter the PK or safety profile of capecitabine or cisplatin in Japanese patients with HER2-positive AGC.