Anticancer Properties of Platinum Nanoparticles and Retinoic Acid: Combination Therapy for the Treatment of Human Neuroblastoma Cancer.

Neuroblastoma is the most common extracranial solid tumor in childhood. The different treatments available for neuroblastoma are challenged by high rates of resistance, recurrence, and progression, most notably in advanced cases and highly malignant tumors. Therefore, the development of more targeted therapies, which are biocompatible and without undesired side effects, is highly desirable. The mechanisms of actions of platinum nanoparticles (PtNPs) and retinoic acid (RA) in neuroblastoma have remained unclear. In this study, the anticancer effects of PtNPs and RA on neuroblastoma were assessed. We demonstrated that treatment of SH-SY5Y cells with the combination of PtNPs and RA resulted in improved anticancer effects. The anticancer effects of the two compounds were mediated by cytotoxicity, oxidative stress (OS), mitochondrial dysfunction, endoplasmic reticulum stress (ERS), and apoptosis-associated networks. Cytotoxicity was confirmed by leakage of lactate dehydrogenase (LDH) and intracellular protease, and oxidative stress increased the level of reactive oxygen species (ROS), 4-hydroxynonenal (HNE), malondialdehyde (MDA), and nitric oxide (NO), and protein carbonyl content (PCC). The combination of PtNPs and RA caused mitochondrial dysfunction by decreasing the mitochondrial membrane potential (MMP), adenosine triphosphate (ATP) content, number of mitochondria, and expression of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α). Endoplasmic reticulum-mediated stress and apoptosis were confirmed by upregulation of protein kinase RNA-like endoplasmic reticulum kinase (PERK), inositol-requiring enzyme 1 (IRE1), activating transcription factor 6 (ATF6), activating transcription factor 4 (ATF4), p53, Bax, and caspase-3 and down regulation of B-cell lymphoma 2 (BCl-2). PtNPs and RA induced apoptosis, and oxidative DNA damage was evident by the accumulation of 8-hydroxy-2-deoxyguanosine (8-OHdG) and 8-hydroxyguanosine (8-OHG). Finally, PtNPs and RA increased the differentiation and expression of differentiation markers. Differentiated SH-SY5Y cells pre-treated with PtNPs or RA or the combination of both were more sensitive to the cytotoxic effect of cisplatin than undifferentiated cells. To our knowledge, this is the first study to demonstrate the effect of the combination of PtNPs and RA in neuroblastoma cells. PtNPs may be a potential preconditioning or adjuvant compound in chemotherapeutic treatment. The results of this study provide a rationale for clinical evaluation of the combination of PtNPs and RA for the treatment of children suffering from high-risk neuroblastoma.

Peritoneal Surface Disease Severity Score (PSDSS), AGO-score and TIAN model in patients with platinum-sensitive recurrent ovarian cancer treated by cytoreductive surgery plus HIPEC.

In patients with platinum sensitive recurrent ovarian cancer selected for a secondary cytoreduction, the use of prognostic scores allows predicting the possibilities of a new complete cytoreduction. The aim of this work is to evaluate the usefulness of PSDSSov, the AGO-score and the TIAN-model as prognostic tools in these patients. Sixty four patients with recurrent platinum sensitive ovarian cancer treated by cytoreduction and HIPEC were analyzed between January 2008 and December 2016. Since 2012, the data needed to calculate the PSDSS, AGO-score and TIAN model were collected prospectively. Fifty patients (78%) received systemic chemotherapy before cytoreduction and HIPEC. In 57 patients (89%) a CC-0 was achieved. Patients with PSDSSov I-II and TIAN model of "low risk" had a DFS at 1 and 5 years of 71% and 57%, respectively, without reaching the median of DFS. PSDSSov is a useful prognostic tool and can be used in decision making in patients with peritoneal carcinomatosis due to recurrent platinum-sensitive ovarian cancer. Its combination with the Tian model makes it possible to identify patients with an especially favorable prognosis.

Immunotherapy: last bullet in platinum refractory germ cell testicular cancer.

Testicular germ cell tumors are chemosensitive with very high cure-rates even in the metastatic setting. However, patients with platinum-refractory and relapsing tumors after autologous stem cell transplant have very poor outcomes despite salvage treatments, and with no effective alternative therapies. Immunotherapy, notably with PD-1 inhibitors, has proven to be very effective in treating various solid tumors. This review summarizes the experience with anti-PD-1 agents (pembrolizumab, nivolumab) in the treatment of testicular germ cell tumor relapsing after multiple lines of treatment, and exposes future trials evaluating newer checkpoint inhibitors in this setting.

Clinical impact of pretreatment prognostic nutritional index (PNI) in small cell lung cancer patients treated with platinum-based chemotherapy.

INTRODUCTION: Numbers of prognostic factors of small cell lung cancer (SCLC) have been demonstrated in previous studies. However, the identification of biomarkers with easy access, convenience, and low consumption is of great value in clinics. OBJECTIVES: In order to find such a biomarker, a single institution study with 1156 SCLC patients was retrospectively conducted to assess the prognostic value of prognostic nutritional index (PNI) on SCLC patients treated with platinum-based chemotherapy. METHODS: The optimal cut-off values were determined by a receiver operating characteristic (ROC) curve analysis. Univariate and multivariate analyses were used to assess their prognostic values for overall survival (OS). RESULTS: On univariate analysis, age, smoking history, tumor stage, PNI, radiotherapy, and surgery were significantly associated with OS. Age, stage, PNI, radiotherapy, and surgery held statistical significance on multivariate analysis. High PNI was closely associated with younger age, limited disease, and radiotherapy. PNI was also demonstrated to be an independent prognostic factor in subgroups analysis, especially in patients with age ≤ 60, no smoking history, no family history of tumor, and no radiotherapy. CONCLUSIONS: Age ≤ 60 years, limited disease, high PNI, radiotherapy, and surgery were independent positive prognostic factors of SCLC patients treated with chemotherapy. PNI was a good biomarker for the assessment of SCLC prognosis for its easy access, convenience to be calculated, and low consumption. Pretreatment PNI can better predict the prognosis of SCLC, especially in patients with age ≤ 60, no smoking history, no family history of tumor, and no radiotherapy.

Comparative toxicities of 3 platinum-containing chemotherapy regimens in relapsed/refractory lymphoma patients.

Optimal salvage chemotherapy regimen for patients with relapsed or refractory Hodgkin and non-Hodgkin lymphoma remains unclear but often based on platinum regimens. This retrospective study assesses in real life the toxicities profiles of patients with relapsed or refractory lymphoma treated with DHA (dexamethasone, high dose aracytine cytarabine) plus platinum salt (dexamethasone-High dose aracytine (cis)platin (DHAP), dexamethasone-High dose aracytine carboplatin (DHAC), or dexamethasone-High dose aracytine Oxaliplatin (DHAOX)), from February 2007 to May 2013 in 2 French hospitals. Toxicities were recorded from medical files and assessed according to the National Cancer Institute Common Toxicity Criteria version 3.0. Potential risk factors of renal insufficiency were tested by univariate analyses. A total of 276 patients were treated: 168 with DHAP (60.9%), 79 with DHAOX (28.6%), and 29 with DHAC (10.5%). Rituximab was associated in 80.1% of patients (n = 221). Renal failure was reported in 97 patients, mainly with cisplatin regimen (86.6%) leading to 8.9% grade III to IV renal failure (P = .001). Renal insufficiency was reversible in most patients but remained persistent in 24, with all of them being treated with DHAP except 1. Cisplatin-based regimen (50.0% versus 12.0%, P < .05) and female (44.6% versus 29.7%, P < .05) appeared to be at higher risks of renal failure. Platinum cumulative dose is a significant risk factor of nephrotoxicity. Hematologic toxicity was more frequent with carboplatin and cisplatin with at least 1 event (all toxicity grade) respectively in 79.3% and 71.4% of patients treated (P < .005). Auditory toxicity was mainly reported with cisplatin (n = 19; 4 grade I-II and 15 grade III-IV). Oxaliplatin was implicated in 77.6% of neurotoxicity (n = 59), mainly moderate (grade I-II). In conclusion, DHAOX and DHAC regimens have more favorable toxicity profile than DHAP regimen. Their lack of renal toxicity makes them attractive regimens, which may be interesting for patients eligible for autologous stem cell transplantation. Nevertheless, these results have to be confirmed by the therapeutic efficacy of these 3 regimens.

An upconversion nanoplatform for simultaneous photodynamic therapy and Pt chemotherapy to combat cisplatin resistance.

Platinum-based antineoplastic drugs are among the first-line chemotherapeutic agents against a variety of solid tumors, but toxic side-effects and drug resistance issues limit their clinical optimization. Novel strategies and platforms to conquer cisplatin resistance are highly desired. Herein, we assembled a multimodal nanoplatform utilizing 808 nm-excited and biocompatible core-shell-shell upconversion nanoparticles (UCNPs) [NaGdF4:Yb/Nd@NaGdF4:Yb/Er@NaGdF4] that were covalently loaded with not only photosensitizers (PSs), but also Pt(iv) prodrugs, which were rose bengal (RB) and c,c,t-[Pt(NH3)2Cl2(OCOCH2CH2NH2)2], respectively. The UCNPs had the capability to convert near infrared (NIR) light to visible light, which was further utilized by RB to generate singlet oxygen. At the same time, the nanoplatform delivered the Pt(iv) prodrug into cancer cells. Thus, this upconversion nanoplatform was able to carry out combined and simultaneous photodynamic therapy (PDT) and Pt chemotherapy. The nanoplatform was well characterized and the energy transfer efficiency was confirmed. Compared with free cisplatin or UCNPs loaded with RB only, our nanoplatform showed significantly improved cytotoxicity upon 808 nm irradiation in both cisplatin-sensitive and -resistant human ovarian cancer cells. A mechanistic study showed that the nanoparticles efficiently delivered the Pt(iv) prodrug into cancer cells, resulting in Pt-DNA damage, and that the nanoplatform generated cellular singlet oxygen to kill cancer cells. We, therefore, provide a comprehensive strategy to use UCNPs for combined Pt chemotherapy and PDT against cisplatin resistance, and our nanoplatform can also be used as a theranostic tool due to its NIR bioimaging capacity.

Phase II study of docetaxel, cisplatin, and concurrent radiation followed by platinum-based adjuvant chemotherapy for technically unresectable, locally advanced head and neck squamous cell carcinoma.

BACKGROUND: Phase I study of weekly administration of low-dose docetaxel/cisplatin concurrent with conventionally fractionated radiotherapy for locally advanced head and neck squamous cell carcinoma suggested the recommended dose of docetaxel at 10 mg/m2 and cisplatin at 20 mg/m2. Phase II study of the concurrent chemoradiotherapy for technically resectable disease showed satisfactory results. METHODS: This phase II study was designed to address efficacy and safety when patients with technically unresectable disease were treated with concurrent chemoradiotherapy, followed by two cycles of moderate-dose platinum-based adjuvant chemotherapy: docetaxel, cisplatin, and fluorouracil (modified TPF). Modified TPF was replaced with docetaxel/carboplatin when renal impairment became evident. Surgical salvage was considered when residual or recurrent locoregional disease was technically resectable and free of distant metastasis. RESULTS: Of 33 enrolled patients, 31 were analyzable: 24 (78 %) and 18 (58 %) patients completed chemoradiotherapy and adjuvant chemotherapy, respectively; 15 (48 %) patients completed study treatment per protocol, and overall complete response rate was 45 %. Seven patients underwent surgical salvage, which was successful in 4 patients. At a median follow-up of 60.8 months for surviving patients, median progression-free survival and median overall survival were 16.2 and 39.9 months, respectively. Grade 3 or 4 toxicity included mucositis (77 %) and dysphagia (45 %) during the chemoradiotherapy period and neutropenia (100 %) and febrile neutropenia (35 %) during the adjuvant period. No patient died of toxicity. CONCLUSION: The tested regimen seems effective, although there is room for improvement in adjuvant chemotherapy because of the high toxicity and low compliance of modified TPF.

ß-lactoglobulin-pectin Nanoparticle-based Oral Drug Delivery System for Potential Treatment of Colon Cancer.

Colon cancer is one of the most common internal malignancies, and conventional chemotherapy is not effective in its treatment. Nanoparticles hold tremendous potential as an effective drug delivery system. The physicochemical properties of ß-lactoglobulin, the main whey protein of cow's milk, such as its stability at low pH, its resistance to gastric protease, and its ability to bind hydrophobic ligands, give it potential for transporting drugs specifically for colon cancer. In the present research, ß-lactoglobulin-pectin nanoparticles were designed to transfer a newly synthesized, anticancer platinum complex (bipyridine ethyl dithiocarbamate Pt(II) nitrate), to the colon. The effects of multiple factors on the size and the colloidal stability of the nanoparticles were studied using dynamic light scattering and scanning electron microscopy techniques. Results showed that the best particle size and highest colloidal stability were obtained in phosphate buffer, pH 4.5, with 0.5 mg/mL ß-lactoglobulin and 0.025-0.05wt% pectin. The drug release profile in simulated gastrointestinal conditions demonstrated that ß-lactoglobulin with a secondary coating is stable in acidic conditions but is able to release its cargo at pH 7. Hence, these nanoparticles have potential to serve as novel and effective vehicles for oral drug delivery preparations.

In vivo evaluation of folate decorated cross-linked micelles for the delivery of platinum anticancer drugs.

The biodistribution of micelles with and without folic acid targeting ligands were studied using a block copolymer consisting of acrylic acid (AA) and polyethylene glycol methyl ether acrylate (PEGMEA) blocks. The polymers were prepared using RAFT polymerization in the presence of a folic acid functionalized RAFT agent. Oxoplatin was conjugated onto the acrylic acid block to form amphiphilic polymers which, when diluted in water, formed stable micelles. In order to probe the in vivo stability, a selection of micelles were cross-linked using 1,8-diamino octane. The sizes of the micelles used in this study range between 75 and 200 nm, with both spherical and worm-like conformation. The effects of cross-linking, folate conjugation and different conformation on the biodistribution were studied in female nude mice (BALB/c) following intravenous injection into the tail vein. Using optical imaging to monitor the fluorophore-labeled polymer, the in vivo biodistribution of the micelles was monitored over a 48 h time-course after which the organs were removed and evaluated ex vivo. These experiments showed that both cross-linking and conjugation with folic acid led to increased fluorescence intensities in the organs, especially in the liver and kidneys, while micelles that are not conjugated with folate and not cross-linked are cleared rapidly from the body. Higher accumulation in the spleen, liver, and kidneys was also observed for micelles with worm-like shapes compared to the spherical micelles. While the various factors of cross-linking, micelle shape, and conjugation with folic acid all contribute separately to prolong the circulation time of the micelle, optimization of these parameters for drug delivery devices could potentially overcome adverse effects such as liver and kidney toxicity.

A platinum(II) complex of liriodenine from traditional Chinese medicine (TCM): Cell cycle arrest, cell apoptosis induction and telomerase inhibition activity via G-quadruplex DNA stabilization.

Liriodenine (L), an antitumor active ingredient from the traditional Chinese medicine (TCM), Zanthoxylum nitidum, afforded a platinum(II) complex (1) of L, cis-[PtCl2(L)(DMSO)], which previously reported for its in vitro antitumor activity and intercalative binding with DNA. In this study, complex 1 was further discussed for its antitumor mechanism and structure-activity relationship, comparing with L and cisplatin. Towards the most sensitive BEL-7404 human hepatoma cells, complex 1 significantly induced cell cycle arrest at both G2/M phase and S phase. It suggests that double helix DNA is not the simplex intracellular target for 1. On the other hand, the BEL-7404 cells incubated with 1 and stained by Hoechst 33258 and AO/EB showed typical cell apoptosis in dose-dependent manner. The BEL-7404 cells incubated with 1 and stained by JC-1 were also characteristic for cell apoptosis on the loss of mitochondrial membrane potential. Furthermore, the G-quadruplex DNA binding property of complex 1 was also investigated by spectroscopic analyses, fluorescent indicator displacement (FID) assay and fluorescence resonance energy transfer (FRET) assay. The results indicated that 1 stabilized the human telomeric G4-HTG21 DNA better than L. The telomerase inhibition ratio of 1 ((62.50±0.03)%), which was examined by telomerase polymerase chain reaction-enzyme-linked immunosorbent assay (PCR-ELISA), was much higher than L ((21.77±0.01)%). It can be ascribed to the better G4-HTG21 DNA stabilization of 1 than L. The results suggested that the nuclei, mitochondria and telomerase via G-quadruplex DNA stabilization all should be key targets for the antitumor mechanism of 1, in which the central platinum(II) played a key role.

Phase II study on Javanica oil emulsion injection (Yadanzi®) combined with chemotherapy in treating patients with advanced lung adenocarcinoma.

PURPOSE: To investigate the efficacy and safety of Javanica oil emulsion injection (Yadanzi®) combined with pemetrexed and platinum (PP) for treating patients with advanced lung cancer. PATIENTS AND METHODS: From June 2011 to June 2013, we recruited 58 patients with advanced lung cancer, and divided them into two groups. Twenty eight patients received Yadanzi® (from ZheJiang Jiuxu Pharmaceutical Co., Ltd.) together with PP chemotherapy (combined group), while the others were given only PP chemotherapy (control group). After two cycles of treatment, efficacy and safety of treatment were evaluated. RESULTS: The overall response rate [(CR+PR+SD)/(CR+PR+SD+PD)] of the combined group was higher than that of control group (89.7% vs. 86.2%, p>0.05). Regarding rate of life improvement, it was 82.8% in combined group, and 51.7% in the control group (p<0.05). In terms of side effects, leukopenia in combined group was less frequent than that in control group (p<0.05). More patients in the control group were found to suffer liver toxicity. CONCLUSIONS: Javanica oil emulsion injection combined with chemotherapy could be considered as a safe and effective regimen in treating patients with advanced lung adenocarcinoma. It can improve the quality of life and reduce the possibility of leukopenia. Further clinical trials with a large sample size should be conducted to confirm whether addition of Yadanzi® to chemotherapy could increase the response rate, reduce toxicity, enhance tolerability and improve quality of life for patients with advanced lung cancer.

Neo-adjuvant chemotherapy in advanced hypopharyngeal carcinoma.

OBJECTIVE: The aim of this retrospective study was to find out the role of neo-adjuvant chemotherapy (NACT) in changing the management and outcome of advanced hypopharyngeal cancer patients. MATERIALS AND METHODS: This is a retrospective analysis of 59 treatment naïve, advanced hypopharyngeal cancer patients presenting to our tertiary care center from April 2010 to October 2011. NACT was given as two (platinum with taxane) or three drug with (platinum, taxane with 5-flurouracil [5 FU]) as 3 weekly regimen with cisplatin and docetaxel as 75 mg/m 2 each, 5-FU as 1000 mg/m 2 . NACT was either given with the intent of achieving: (1) surgical resection (extensive soft tissue disease, oropharyngeal involvement, extensive disease with cartilage erosion) or (2) organ preservation (Bulky disease with inner cartilage erosion, exolaryngeal disease without cartilage erosion, large N3 nodes). RESULTS: The mean age of this population was 55 years. Most (83%) of the patients had pyriform sinus (PFS) involvement. 69% patients had Stage IVa disease, 21% Stage IVb and 10% Stage III. The overall response rate was 66%, including 06% complete responses and 60% partial responses. Following NACT, resectability was achieved in 30% (10/33) and organ preservation protocol was planned after NACT in 73% (19/26) patients. The main toxicities were neutropenia (grade 3, 4, 04%; febrile neutropenia, 4%), mucositis 5%, diarrhea 5%. The median progression free survival was 20 months. CONCLUSIONS: NACT can be useful in patients with oropharyngeal involvement to achieve surgical resection and larynx preservation in patients with bulky T3 disease.

Phase 2 study of sorafenib in malignant mesothelioma previously treated with platinum-containing chemotherapy.

INTRODUCTION: The incidence of mesothelioma is rising. First-line cisplatin and pemetrexed confers a survival benefit, with a median progression-free survival (PFS) of 5.7 months. Sorafenib inhibits tyrosine kinases, including receptors for vascular endothelial growth factor, which are implicated in mesothelioma pathogenesis by preclinical and clinical data. METHODS: Sorafenib, at 400 mg twice daily, was assessed in a single-arm multicenter phase 2 study, using Simon's two-stage design. Eligible patients had received platinum combination chemotherapy earlier. The primary endpoint was PFS at 6 months, with secondary endpoints, including response rate and metabolic response, assessed using fluorodeoxyglucose positron emission tomography. Published reference values for PFS in mesothelioma provide a benchmark for the null hypothesis of 28% progression-free at 6 months, and for moderate or significant clinical activity of 35% or 43% progression-free at 6 months, respectively. RESULTS: Fifty-three patients (72%) were treated. Most had epithelioid histology. Ninety-three percent of patients had a performance status 0 or 1. Treatment was well tolerated with few grade 3 or 4 toxicities. Median PFS was 5.1 months, with 36% of patients being progression-free at 6 months. Nine percent of patients remained on study beyond 1 year. Changes in fluorodeoxyglucose positron emission tomography parameters did not predict clinical outcome. CONCLUSIONS: Sorafenib is well tolerated in patients with mesothelioma after completion of platinum-containing chemotherapy. PFS of sorafenib compares favorably with that reported for other targeted agents, and suggests moderate activity in this disease.

Outcomes of induction chemotherapy followed by concurrent chemoradiation for nasopharyngeal carcinoma.

PURPOSE: Current standard therapy for nasopharyngeal carcinoma (NPC) is concurrent chemoradiation based on randomized data. However, limited randomized data exist to support the addition of induction chemotherapy (ICT). METHODS: 58 Patients with NPC were treated from 1990 to 2010. All patients received platinum-based ICT. All 58 patients were treated with chemoradiation, 57 in a week-on/week-off (WOWO) fashion. Concurrent chemotherapy included hydroxyurea/5-fluorouracil for all patients. Median radiation dose was 70 Gy. No patient received adjuvant chemotherapy. RESULTS: AJCC 2009 stage was II=13, III=21, IVa=13, and IVb=11. Median follow-up for surviving patients was 66 months. Response to ICT was complete response (CR) 17% and partial response (PR) 64%. The CR rate after chemoradiation was 96%. Five-year actuarial freedom from local failure (FFLF), freedom from distant failure (FFDF), cause-specific survival (CSS), and overall survival (OS) was 98%, 90%, 90%, and 76%, respectively. Analysis of pediatric patients (n=9) demonstrated 5-year actuarial FFLF, FFDF, CSS, and OS of 100%, 88%, 80%, and 80%, respectively. CONCLUSIONS: ICT followed by concurrent chemoradiation demonstrates excellent FFLF, FFDF, CSS, and OS with tolerable toxicity. Induction chemotherapy followed by concurrent chemoradiation for patients with NPC should be explored further in a randomized setting.

Green synthesis, characterization and anticancer potential of platinum nanoparticles Bioplatin.

OBJECTIVE: In the present study, the anticancer potential of platinum nanoparticles Bioplatin is explored and the mode of interactions of Bioplatin with calf thymus DNA and honey was analyzed. METHODS: Bioplatin was synthesized with the help of green nanotechnology and characterized by particle size, zeta potential and surface morphology. The interaction of Bioplatin with DNA and honey was also checked with the help of circular dichroism spectroscopy and Fourier-transform infrared spectroscopy, respectively. The anticancer potential of Bioplatin was evaluated on peripheral blood mononuclear cells and A375 cells in vitro by analyzing results of MTT (3-(4,5)-dimethyl-thiahiazo-(-z-y1)-3,5-di-phenytetrazoliumromide), fluorescence microscopic studies and DNA fragmentation assay. RESULTS: Bioplatin exhibited a small particle size of 137.5 nm and a surface charge of -35.8 mV. Bioplatin interacted with DNA and brought in effective changes in structure and conformation of DNA, and formed a new complex that increased its stability of DNA intercalated with the base pair of DNA. In vitro studies demonstrated that Bioplatin arrested cell proliferation, and induced chromatin condensation and internucleosomal DNA fragmentation. CONCLUSION: Bioplatin induces apoptosis in cancer cells and may have some beneficial effect against human carcinoma. It interacts with DNA, brings stabilization to DNA, and thus prevents the replication of DNA.

Antitumor effects of nano-bubble hydrogen-dissolved water are enhanced by coexistent platinum colloid and the combined hyperthermia with apoptosis-like cell death.

In order to erase reactive oxygen species (ROS) related with the proliferation of tumor cells by reducing activity of hydrogen, we developed functional water containing nano-bubbles (diameters: <900 nm for 71%/population) hydrogen of 1.1-1.5 ppm (the theoretical maximum: 1.6 ppm) with a reducing ability (an oxidation-reduction potential -650 mV, normal water: +100-200 mV) using a microporous-filter hydrogen-jetting device. We showed that hydrogen water erased ROS indispensable for tumor cell growth by ESR/spin trap, the redox indicator CDCFH-DA assay, and was cytotoxic to Ehrlich ascites tumor cells as assessed by WST-8 assay, crystal violet dye stain and scanning electron microscopy, after 24-h or 48-h incubation sequent to warming at 37°C or 42°C. Hydrogen water supplemented with platinum colloid (0.3 ppm Pt in 4% polyvinylpyrrolidone) had more antitumor activity than hydrogen water alone, mineral water alone (15.6%), hydrogen water plus mineral water, or platinum colloid alone as observed by decreased cell numbers, cell shrinkage and pycnosis (nuclear condensation)/karyorrhexis (nuclear fragmentation) indicative of apoptosis, together with cell deformation and disappearance of microvilli on the membrane surface. These antitumor effects were promoted by combination with hyperthermia at 42°C. Thus, the nano-bubble hydrogen water with platinum colloid is potent as an anti-tumor agent.

A multi-institutional survey of the effectiveness of chemotherapy combined with radiotherapy for patients with nasopharyngeal carcinoma.

BACKGROUND: Previous randomized trials have shown a survival advantage of concurrent platinum-based chemoradiotherapy with or without adjuvant chemotherapy for advanced nasopharyngeal cancer. Applicability of these data to a Japanese population is an important issue which remains to be solved. METHODS: A retrospective survey of treatment of patients with nasopharyngeal cancer in 17 institutions in Japan was done with special reference to the relationship between the type of chemotherapy and survival outcome. Chemotherapy used was classified according to: (i) whether > or =2 courses of platinum plus 5-fluorouracil (FP) was given; or (ii) whether platinum was administered concurrently with radiotherapy (RT). This resulted in three groups being produced consisting of (i)/(ii) = YES/YES, other miscellaneous (MISC) and RT alone. RESULTS: Of 333 evaluable replies, 67 patients (20%) corresponded to the YES/YES, 192 (58%) to the MISC and 74 (22%) to the RT alone group. The YES/YES group achieved a better overall survival than RT alone for patients with intermediate stage (T3N0 or T1-3N1, 81.9 versus 60.7% at 5 years, P = 0.042) and advanced stage (T4 or N2/3, 56.6 versus 31.5%, P = 0.017) disease. The MISC group achieved an almost identical survival rate to that in the YES/YES group for patients with intermediate stage disease (81.9% at 5 years, P = 0.968), whereas it was not significantly different from that of the RT alone group for patients with advanced stage disease (44.0%, P = 0.261). CONCLUSION: The results of this survey mirrored the data from previous randomized trials for patients with intermediate and advanced stage nasopharyngeal cancer in Japan. However, confirmatory prospective trials are required to test the efficacy of less toxic approaches for patients with intermediate stage disease.

Bioavailability of fine dispersed platinum as emitted from automotive catalytic converters: a model study.

Automobile exhaust catalytic converters emit fine dispersed elemental platinum, Pt (0), in the nanometer range coated on larger aluminium oxide carrier particles. A pre-requisite for a potential systemic toxic effect of the emitted platinum is its bioavailability which was investigated using laboratory animals. To this end, a model substance was synthesised which consisted of aluminium oxide particles < or = 5 microns onto which platinum particles > or = 4 nm were deposited by a calcination process. These particles closely resemble those emitted from automobile exhaust converters. This model substance was applied to female Lewis rats in two doses by intratracheal instillation; the animals were killed after 1, 7, 28 and 90 days. In addition, the model substance was also applied during a 90-day inhalation study. After microwave digestion of the tissues, the platinum was determined in all organs and body fluids by inductively coupled plasma/mass spectrometry (ICP/MS). Platinum was found in the blood, urine and faeces and all important organs (liver, spleen, kidneys, adrenals, stomach, femur). Based on the platinum content determined in the body fluids and all organs (except the lung and the faeces) it was calculated that up to 16% of the platinum was retained in the lung 1 day after intratracheal instillation and up to 30% of the fine dispersed platinum deposited on an average during 90 days inhalation in the lung was bioavailable. Using size exclusion chromatography (SEC) in combination with ICP/MS, it was shown that > or = 90% of the bioavailable platinum was bound to high molecular weight compounds (approximately 80-800 kDa), most likely proteins.

Dose-response relationships of alimentary PtCl2 and PtCl4 in growing rats.

In experiments with rats dose-response relationships of alimentary PtCl2 and PtCl4 were investigated. 2 x 81 animals weighing 35 g were randomly distributed among 9 treatment groups which were fed ad libitum with a synthetic diet containing various amounts of Pt during 4 weeks. Pt was added in the form of PtCl2 or PtCl4 in the amounts 0; 0.01; 0.05; 0.10; 0.50; 1.0; 5.0; 10 and 50 mg/kg diet. The Pt supplementation had no influence on life mass gain or food consumption. In the case of 50 mg/kg Pt in the form of PtCl4 the erythrocyte count and hematocrit were reduced by about 13% in comparison with the control group. Dependent on the Pt dose, the application of PtCl4 and PtCl2 induced Pt retention in nearly all tissues especially in kidney. The effects were greater with PtCl4 than with PtCl2. As a result of the higher Pt retention in the kidneys, the serum creatinine was increased for the higher doses of PtCl4.