A high-performance liquid chromatographic assay for determination of cisplatin in plasma, cancer cell, and tumor samples

Using HPLC for the determination of platinum drugs in biological matrixes after derivatization with diethyldithiocarbamate

Challenges and pitfalls in the application of diethyldithiocarbamate derivatization for LC analysis of cisplatin and oxaliplatin, as well as the suitability of this method for different biological matrices with implications for use in routine practice have been identified. The LC of platinum drugs presents a significant challenge. They are polar compounds with poor retention on reverse phase packings. Cisplatin also exhibits poor absorption in UV and ionization in mass spectrometry. Therefore, we developed and optimized a derivatization approach for the LC analysis of total platinum in plasma, plasma ultrafiltrate, peritoneal fluid, and urine. Derivatization in urine proved to be difficult due to the complexity of the matrix, and extended testing was required. Our results highlight the important issues affecting the efficiency, reliability, and suitability of platinum drug derivatization. Although precolumn derivatization is less selective than its postcolumn counterpart, the application of precolumn derivatization is a simple, rapid, and universal approach for the determination of platinum drugs by HPLC. One of its major advantages is that it allows a more affordable analysis using UV detection without the need for additional high-end instrumentation such as a MS detector.

Preparation, characterization and in vitro evaluation of cisplatin-bound triblock polymeric micelle solution for ovarian cancer treatment

The main objective of this study was to prepare cisplatin (CDDP) bound triblock polymeric micelle solution which will have a hydrophilic shell not being phagocytosed by mononuclear phagocyte system, and evaluate in vitro behavior for the treatment of ovarian cancer. For this aim, CDDP was bound to polyglutamic acid (PGA) and the triblock polymer was prepared using polyethylene glycol)-polylactide-co-glycolide (PEG-PLGA). CDDP-bound triblock copolymer conjugation was characterized, in vitro release and permeability studies were performed using USP II method and Caco-2 cell lines, respectively. The release of CDDP from CDDP-bound triblock polymeric micelle solution was found 87.3 ± 3.56% at the end of the 24th hour. CDDP bound triblock polymeric micelle solution was detected as biocompatible, and permeable according to in vitro studies. According to the MTT results, the measured cytotoxicity was found to be maximum in CDDP-bound triblock polymeric micelle solution when compared with CDDP solution and conjugate in SKOV-3 and OVCAR-3 cells, whereas annexin V-FITC apoptosis results were found to be maximum in A2780 cells.

Wedelolactone protects against cisplatin-induced nephrotoxicity in mice via inhibition of organic cation transporter 2

The balance of cisplatin uptake and efflux, mediated mainly by organic cation transporter 2 (OCT2) and multidrug and toxin extrusion 1 (MATE1), respectively, determines the renal accumulation and nephrotoxicity of cisplatin. Using transporter-mediated cellular uptake assay, we identified wedelolactone (WEL), a medicinal plant-derived natural compound, is a competitive inhibitor of OCT2 and a noncompetitive inhibitor of MATE1. Wedelolactone showed a selectivity to inhibit OCT2 rather than MATE1. Cytotoxicity studies revealed that wedelolactone alleviated cisplatin-induced cytotoxicity in OCT2-overexpressing HEK293 cells, whereas it did not alter the cytotoxicity of cisplatin in various cancer cell lines. Additionally, wedelolactone altered cisplatin pharmacokinetics, reduced kidney accumulation of cisplatin, and ameliorated cisplatin-induced acute kidney injury in the Institute of Cancer Research mice. In conclusion, these findings suggest a translational potential of WEL as a natural therapy for preventing cisplatin-induced nephrotoxicity and highlight the need for drug-drug interaction investigations of WEL with other treatments which are substrates of OCT2 and/or MATE1.

Analytical methods for the quantification of cisplatin, carboplatin, and oxaliplatin in various matrices over the last two decades

Background:

Platinum derivatives including cisplatin and its later generations carboplatin, and oxaliplatin remain the most largely used drugs in the therapy of malignant diseases. They exert notable anticancer activity towards numerous types of solid tumors such as gastric, colorectal, bladder, ovary, and several others. The chemotherapeutic activity of these compounds, however, is associated with many unwanted side effects and drug resistance problems limiting their application and effectiveness. Proper dosage is still an inherent problem, as these drugs are usually prescribed in small doses.

Objective:

Several analytical methods have been reported for the accurate quantification of cisplatin, carboplatin, and oxaliplatin and their metabolites either alone or in combination with other chemotherapeutic drugs, in different matrices such as pharmaceutical formulations, biological fluids, cancer cells, and environmental samples. The main goal of this review is to systematically study the analytical methods already used for the analysis of cisplatin, carboplatin, and oxaliplatin in various matrices during the last two decades.

Results and Conclusion:

In the literature, reviews showed that numerous analytical methods such as electroanalytical, UV-visible spectrophotometry, chromatographic, fluorescence, atomic absorption spectrophotometry, and other spectroscopic methods combined with mass spectrometry were used for the determination of these compounds in various matrices.

Fabrication, optimisation and evaluation of cisplatin-loaded nanostructured carriers for improved urothelium permeability for intravesical administration

AIM

To design microemulsions as carriers to improve cisplatin permeation capability for intravesical administration.

METHOD

The response surface methodology with factorial design was used to investigate and optimise the influence of the compositions e.g. capryol 90 and 5-pentanediol/transcutol mixture on the permeation accumulation amount and tissue deposition amount of cisplatin-loaded microemulsions. The in vitro permeation study and in vivo intravesical test were conducted to prove the effect of microemulsions.

RESULTS

The droplet size and the viscosity of all drug-loaded formulations ranged 235.8-309.3 nm and 550.8-861.7 cps, respectively. The permeation accumulation amounts significantly increased about 26-fold, by used microemulsion as carriers. In vivo study, the cisplatin deposition amount in bladder tissue significantly increased 4.1-fold (p < 0.05) and the penetration depth increased from 60 μm up 120 μm. The nanocarrier showed considerable thermodynamic stability.

CONCLUSION

The designed nanocarrier was considered to be a promising delivery system for cisplatin intravesical administration.

A New Sensitive Method for Quantitative Determination of Cisplatin in Biological Samples by Kinetic Spectrophotometry

This study describes a kinetic spectrophotometric method for accurate, sensitive and rapid determination of cisplatin in biofluids. The developed method is based on the inhibitory effect of cisplatin on the oxidization of Janus Green by bromate in acidic media. The change in absorbance as the criteria of the oxidation reaction was followed spectrophotometrically. To obtain the highest rate of sensitivity, efficient reaction parameters were optimized. Under optimum experimental conditions, a calibration graph was obtained linearly over the range 10.0 - 5750.0 μg L^-1 and the limit of detection (3s_b/m) was 4.2 μg L^-1 of cisplatin. The interfering effect of diverse species was investigated. The developed method was used for the quantification of cisplatin in bio fluids of patients treated with cisplatin, spiked bio fluids and pharmaceutical samples and yielded satisfactory results.

Co-Delivery of Cisplatin and Gemcitabine via Viscous Nanoemulsion for Potential Synergistic Intravesical Chemotherapy

Combined chemotherapy is an effective and safe treatment for cancers. Co-administration of cisplatin and gemcitabine produces a synergistic effect for bladder cancer treatment, so viscous microemulsions were developed for co-delivery of cisplatin and gemcitabine to extend the retention time and improve the permeability of chemotherapeutic drugs into the urothelium by intravesical administration. Results showed that the deposition amounts of cisplatin and gemcitabine significantly increased in in vitro and in vivo study. The penetration depth in bladder tissue samples increased from 60 to 120 μm. The dual-loaded formulation also showed thermodynamic and chemical stability, demonstrating that these gel-based microemulsions are promising drug delivery carriers for chemotherapy agents by intravesical administration.

Paradoxical Effect of Grape Pomace Extract on Cisplatin-Induced Acute Kidney Injury in Rats

Cisplatin is one of the most used drugs in the therapy of different types of cancer. However, its use is limited by nephrotoxicity. This study investigated the effects of a commercially available grape pomace extract (GE) from Vitis vinifera on cisplatin-induced kidney toxicity in rats. Sixty-four male Wistar albino rats were randomly divided into eight groups. Groups 1–3 were controls, receiving 0.9% saline and doses 1 and 2 of GE respectively. Cisplatin was given to groups 4–8. Two groups received pretreatment with GE, while another two groups received pre- and post-treatment with GE. Blood samples were collected and all animals sacrificed. Kidneys were harvested for histopathological analysis. GE significantly increased blood creatinine and urea levels, the severity of kidney histopathological damage, and mortality in all cisplatin groups, except for group 7 which received pre- and post-treatment with a low dose of GE. Renal toxicity was determined by mortality and severe histopathological renal lesions. Additionally, the serum total antioxidant capacity (TAC) was not significantly modified in the treated groups compared to the control. These results indicate that the GE did not have a protective effect on cisplatin-induced nephrotoxicity; on the contrary, GE accentuated the toxic effect of cisplatin.

Targeted Delivery of Cisplatin-Derived Nanoprecursors via a Biomimetic Yeast Microcapsule for Tumor Therapy by the Oral Route

Targeted therapy via the patient-friendly oral route remains the holy grail of chemotherapy for cancer. Herein we report a yeast-derived platform for targeted oral delivery of cisplatin (CDDP) that is one of the most effective drugs for chemotherapy of various types of cancers. Methods: The optimal conditions were first established to fabricate yeast microcapsules (YCs) with desirable loading capability. Then, CDDP-derived precursor nanoparticles (PreCDDP) were prepared and packaged into YC to produce orally deliverable PreCDDP/YC. The physiochemical properties, in vitro drug release profiles, in vitro antitumor activity, oral targeting capability, in vivo pharmacokinetics, and in vivo efficacy of the YC-based biomimetic delivery system were examined. Results: YCs obtained under the optimized condition showed desirable loading efficiency for quantum dots that were used as a model nanocargo. In vitro experiments demonstrated rapid endocytosis and prolonged retention of YC in macrophages. By electrostatic force-mediated self-deposition, PreCDDP was efficiently loaded into YC. PreCDDP/YC showed potent cytotoxicity in different tumor cells, indicating that PreCDDP loaded in YC maintained its antitumor activity after intracellular release. As compared to CDDP and PreCDDP, orally administered PreCDDP/YC displayed significantly higher bioavailability. Post oral delivery, YC could accumulate in A549 human lung carcinoma xenografts in mice, achieving by monocyte/macrophage-mediated translocation via the lymphatic system. Through this targeting effect, orally administered PreCDDP/YC showed desirable efficacy in A549 xenograft-bearing mice, which was comparable to that of free CDDP administered by intravenous injection. Orally administered free CDDP, however, did not afford antitumor effects. Furthermore, oral treatment with PreCDDP/YC displayed better safety than free CDDP administered via the oral or intravenous route. Conclusions: This biomimetic approach can serve as an effective strategy to develop targeted oral chemotherapies based on CDDP or its derivatives.

GMDTC Chelating Agent Attenuates Cisplatin-Induced Systemic Toxicity without Affecting Antitumor Efficacy

Cisplatin is a platinum-based chemotherapeutic drug widely used in the treatment of various cancers such as testicular, ovarian, lung, bladder, and cervical cancers. However, its use and the dosage range applied have been limited by severe side effects (e.g., nephrotoxicity and ototoxicity) and by the development of resistance to cisplatin in patients during treatment. Metal chelators have shown promising potential in overcoming these problems often associated with platinum drugs. Previously, a new chelating agent, sodium (S)-2-(dithiocarboxylato((2S,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl)amino)-4(methylthio)butanoate (GMDTC), was developed. In this study, we examined the effect of GMDTC in modifying cisplatin-induced toxicities following in vitro and in vivo exposures. GMDTC treatment dramatically reduced cisplatin-induced apoptosis and cytotoxicity in HK2 cells by decreasing the amount of intracellular platinum. In the 4T1 breast cancer mouse model, GMDTC reduced cisplatin-induced nephrotoxicity by reducing cisplatin deposition in the kidney. GMDTC attenuated cisplatin-induced elevations in blood urea nitrogen and plasma creatinine, ameliorated renal tubular dilation and vacuolation, and prevented necrosis of glomeruli and renal tubular cells. GMDTC also inhibited cisplatin-induced ototoxicity as shown by improved hearing loss which was assessed using the auditory brainstem response test. Furthermore, GMDTC attenuated cisplatin-induced hematotoxicity and hepatotoxicity. Importantly, co-treatment of cisplatin with GMDTC did not affect cisplatin antitumor efficacy. Tumor growth, size, and metastasis were all comparable between the cisplatin only and cisplatin-GMDTC co-treatment groups. In conclusion, the current study suggests that GMDTC reduces cisplatin-induced systemic toxicity by preventing the accumulation and assisting in the removal of intracellular cisplatin, without compromising cisplatin therapeutic activity. These results support the development of GMDTC as a chemotherapy protector and rescue agent to overcome the toxicity of and resistance to platinum-based antineoplastic drugs.

GSTM1, GSTT1 and GSTP1 Ile105Val polymorphisms in outcomes of head and neck squamous cell carcinoma patients treated with cisplatin chemoradiation

Cisplatin (CDDP) combined with radiotherapy (RT) is employed in head and neck squamous cell carcinoma (HNSCC) with variable toxicities and clinical response. Glutathione S-transferases (GSTs) participate in CDDP excretion from cells, and genes encoding GSTs, GSTM1, GSTT1and GSTP1, are polymorphic in humans. This prospective study aimed to evaluate the roles of GSTM1, GSTT1, and GSTP1 Ile105Val polymorphisms in outcomes of HNSCC patients treated with CDDP chemoradiation. Ninety patients were genotyped by multiplex PCR. Urinary CDDP measurements were performed by HPLC. Treatment side effects and response were analysed by conventional criteria. Patients with GSTT1 genes showed 7.23- and 5.37-fold higher likelihood of presenting vomiting and ototoxicity, lower glomerular filtration rate (GFR), and lower elimination of CDDP in urine relative to patients with deleted genes. Patients harbouring the GSTP1 IleVal or ValVal genotypes showed 4.28-fold higher likelihood of presenting grade 2 or 3 vomiting and lower GFR with treatment than those harbouring the IleIle genotype. In multivariate Cox analysis, patients with the GSTP1 105ValVal genotype had 3.87 more chance of presenting disease progression than those with the IleIle or IleVal genotype (p < 0.01). Our findings provide preliminary evidence that inherited abnormalities in CDDP metabolism, related to GSTT1 and GSTP1 Ile105Val polymorphisms, alter outcomes of HNSCC patients treated with CDDP and RT.

Pt(IV) hybrids containing a TDO inhibitor serve as potential anticancer immunomodulators

Tryptophan 2,3-dioxygenase (TDO), an immunosuppressive enzyme, can involve in immune evasion and tumor tolerance. TDO inhibitors can boost the efficacy of chemotherapeutics by promoting immunity. Herein, a strategy to introduce a TDO inhibitor into Pt(IV) complexes for reversing tumor immune suppression was adopted. A mono-modified Pt(IV) complex, 3, displayed significant antitumor activity against human liver cancer cells. Flow cytometry study revealed that complex 3 could induce cell death via a mitochondrial-dependent apoptosis pathway and arrest the cell cycle at S phase. Furthermore, complex 3 was effective to enhance T-cell immune responses by inhibiting the TDO enzyme expression to block the kynurenine production and inactivating the downstream of aryl hydrocarbon receptor (AHR).

Polymorphisms in DNA mismatch repair pathway genes predict toxicity and response to cisplatin chemoradiation in head and neck squamous cell carcinoma patients

Head and neck squamous cell carcinoma (HNSCC) is treated with cisplatin (CDDP) and radiotherapy (RT), and distinct results are observed among patients with similar clinicopathological aspects. This prospective study aimed to investigate whether MLH1 c.-93G>A (rs1800734), MSH2 c.211+9C>G (rs2303426), MSH3 c.3133G>A (rs26279), EXO1 c.1765G>A (rs1047840), and EXO1 c.2270C>T (rs9350) single nucleotide polymorphisms (SNPs) of the mismatch repair (MMR) pathway change side effects and response rate of 90 HNSCC patients treated with CDDP and RT. DNA from peripheral blood was analyzed by PCR-based methods to obtain genotypes. It was observed 4.27-fold and 4.69-fold increased risks of presenting pronounced nephrotoxicity with treatment in patients with MSH3 GG and EXO1 rs9350 CC genotypes compared with patients with GA or AA and CT or TT genotypes, respectively. MSH3 GG or GA and GT haplotype of EXO1 rs1047840 and rs9350 SNPs conferred to patients 10.29 and 4.00 more chances of presenting pronounced ototoxicity after treatment than MSH3 AA genotype and other EXO1 haplotypes, respectively. Patients with EXO1 rs1047840 GA or AA genotype and AC haplotype of EXO1 rs1047840 and rs9350 SNPs had both 9.55-fold increased risks of achieving partial response or stable disease instead of complete remission after treatment than patients with EXO1 GG genotype and other EXO1 haplotypes, respectively. For the first time, our data show preliminary indication that inherited alterations of DNA MMR pathway, related to MSH3 rs26279, EXO1 rs1047840 and EXO1 rs9350 SNPs, modify toxicity and response to chemoradiation in HNSCC, and may contribute to future personalized treatment of patients.

Tunable Signal-Off and Signal-On Electrochemical Cisplatin Sensor

We report the first electrochemical cisplatin sensor fabricated with a thiolated and methylene blue (MB)-modified oligo-adenine (A)-guanine (G) DNA probe. Depending on the probe coverage, the sensor can behave as a signal-off or signal-on sensor. For the high-coverage sensor, formation of intrastrand Pt(II)-AG adducts rigidifies the oligo-AG probe, resulting in a concentration-dependent decrease in the MB signal. For the low-coverage sensor, the increase in probe-to-probe spacing enables binding of cisplatin via the intrastrand GNG motif (N = A), generating a bend in the probe which results in an increase in the MB current. Although both high-coverage signal-off and low-coverage signal-on sensors are capable of detecting cisplatin, the signal-on sensing mechanism is better suited for real time analysis of cisplatin. The low-coverage sensor has a lower limit of detection, wider optimal AC frequency range, and faster response time. It has high specificity for cisplatin and potentially other Pt(II) drugs and does not cross-react with satraplatin, a Pt(IV) prodrug. It is also selective enough to be employed directly in 50% saliva and 50% urine. This detection strategy may offer a new approach for sensitive and real time analysis of cisplatin in clinical samples.

XPD c.934G>A polymorphism of nucleotide excision repair pathway in outcome of head and neck squamous cell carcinoma patients treated with cisplatin chemoradiation

This study aimed to investigate the associations of XPC c.2815A>C, XPD c.934G>A and c.2251A>C, XPF c.2505T>C and ERCC1 c.354C>T single nucleotide polymorphisms (SNPs) of nucleotide excision repair pathway in outcome of head and neck squamous cell carcinoma (HNSCC) patients treated with cisplatin (CDDP) chemoradiation. Patients with XPC c.2815AC or CC and XPD c.934GA or AA genotypes had 0.20 and 0.38 less chances of presenting moderate/severe ototoxicity and nausea, respectively. Patients with XPD c.934AA and c.2251AC or CC genotypes had 8.64, 12.29 and 3.55 more chances of achieving complete response (CR), consistent ototoxicity and nephrotoxicity, respectively. AA haplotype of XPD and ACT haplotype of XPD and ERCC1 SNPs were associated with 9.30 and 3.41 more chances of achieving CR and consistent nephrotoxicity, respectively. At 24 months of follow-up, patients with XPD c.934AA genotype presented lower progression-free survival and overall survival in Kaplan-Meier estimates, and differences between groups remained the same in univariate Cox analysis. Patients with XPD c.934AA genotype had 2.13 and 2.04 more risks of presenting tumor progression and death than others in multivariate Cox analysis. Our data present preliminary evidence that XPC c.2815A>C, XPD c.934G>A and c.2251A>C, and ERCC1 c.354C>T SNPs alter outcome of HNSCC patients treated with CDDP chemoradiation.

Adverse drug reactions and kinetics of cisplatin excretion in urine of patients undergoing cisplatin chemotherapy and radiotherapy for head and neck cancer: a prospective study

Background

Cisplatin is a high-potency anticancer agent; however, it causes significant adverse drug reactions (ADRs). Potential pharmacokinetic markers must be studied to predict or prevent cisplatin-induced ADRs and achieve better prognosis. This study was designed to investigate the relationship between ADRs and kinetics of cisplatin excretion in the urine of patients undergoing high-dose cisplatin chemotherapy and radiotherapy for head and neck cancer.

Methods

Outpatients with head and neck cancer received a first cycle of high-dose cisplatin chemotherapy (80–100 mg/m²) concurrent to radiotherapy. ADRs (haematological, renal, and gastrointestinal reactions) were classified based on severity by National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE, version 4, grade 0–4). The kinetics of cisplatin excretion in urine was evaluated by high-performance liquid chromatography over three time periods: 0–12, 12–24, and 24–48 h after the administration of cisplatin. Spearman Correlation test and regression analysis were performed to assess the relationship between ADRs and cisplatin excretion in the urine.

Results

In total, 59 patients with a mean age of 55.6 ± 9.4 years were analysed; most patients were male (86.4%), white (79.7%), and with pharyngeal tumours in advanced stages (66.1%). The most frequently observed ADRs were anaemia (81.4%), lymphopenia (78%), and nausea (64.4%); mostly grades 1 and 2 of toxicity. The mean cisplatin excretion was 70.3 ± 64.4, 7.3 ± 6.3, and 5 ± 4 μg/mg creatinine at 0–12, 12–24, and 24–48 h, respectively. Statistical analysis showed that the amount of cisplatin excreted did not influence the severity of ADRs.

Conclusions

The most frequent ADRs were anaemia, lymphopenia, and nausea. Grades 1 and 2 were the severities for most ADRs. The period over which the highest cisplatin excretion observed was 0–12 h after chemotherapy, and cisplatin excretion could not predict toxicity.

Graphical abstract

Development and Validation of an Inductively Coupled Plasma Mass Spectrometry (ICP-MS) Method for Quantitative Analysis of Platinum in Plasma, Urine, and Tissues

Cisplatin, a platinum chemotherapeutic, is one of the most commonly used chemotherapeutic agents for many solid tumors. In this work, we developed and validated an inductively coupled plasma mass spectrometry (ICP-MS) method for quantitative determination of platinum levels in rat urine, plasma, and tissue matrices including liver, brain, lungs, kidney, muscle, heart, spleen, bladder, and lymph nodes. The tissues were processed using a microwave accelerated reaction system (MARS) system prior to analysis on an Agilent 7500 ICP-MS. According to the Food and Drug Administration guidance for industry, bioanalytical validation parameters of the method, such as selectivity, accuracy, precision, recovery, and stability were evaluated in rat biological samples. Our data suggested that the method was selective for platinum without interferences caused by other presenting elements, and the lower limit of quantification was 0.5 ppb. The accuracy and precision of the method were within 15% variation and the recoveries of platinum for all tissue matrices examined were determined to be 85-115% of the theoretical values. The stability of the platinum-containing solutions, including calibration standards, stock solutions, and processed samples in rat biological matrices was investigated. Results indicated that the samples were stable after three cycles of freeze-thaw and for up to three months.

Characterization and in vitro evaluation of nimotuzumab conjugated with cisplatin-loaded liposomes

In this paper, we report the conjugation of the humanized monoclonal antibody nimotuzumab with cisplatin-loaded liposomes and the in vitro evaluation of its affinity for tumor cells. The conjugation procedure was performed through derivatization of nimotuzumab with N-succinimidyl S-acetylthioacetate (SATA) followed by a covalent attachment with maleimide groups at the end of PEG-DSPE chains located at the membrane of pre-formed liposomes. Confocal microscopy was performed to evaluate the immunoliposome affinity for EGFR antigens from human epidermoid carcinoma (A-431) and normal lung (MRC-5) cell lines. Results showed that the procedures implemented in this work do not affect the capability of the nimotuzumab-immunoliposomes to recognize the tumor cells, which overexpress the EGFR antigens.

Autophagy Inhibition Delays Early but Not Late-Stage Metastatic Disease

The autophagy pathway has been recognized as a mechanism of survival and therapy resistance in cancer, yet the extent of autophagy's function in metastatic progression is still unclear. Therefore, we used murine models of metastatic cancer to investigate the effect of autophagy modulation on metastasis development. Pharmacologic and genetic autophagy inhibition were able to impede cell proliferation in culture, but did not impact the development of experimentally induced 4T1 and B16-F10 metastases. Similarly, autophagy inhibition by adjuvant chloroquine (CQ) treatment did not delay metastasis in an orthotopic 4T1, tumor-resection model. However, neoadjuvant CQ treatment or genetic autophagy inhibition resulted in delayed metastasis development, whereas stimulation of autophagy by trehalose hastened development. Cisplatin was also administered either as a single agent or in combination with CQ. The combination of cisplatin and CQ was antagonistic. The effects of autophagy modulation on metastasis did not appear to be due to alterations in the intrinsic metastatic capability of the cells, as modulating autophagy had no impact on migration, invasion, or anchorage-independent growth in vitro. To explore the possibility of autophagy's influence on the metastatic microenvironment, bone marrow-derived cells (BMDCs), which mediate the establishment of the premetastatic niche, were measured in the lung and in circulation. Trehalose-treated mice had significantly more BMDCs than either vehicle- or CQ-treated mice. Autophagy inhibition may be most useful as a treatment to impede early metastatic development. However, modulating autophagy may also alter the efficacy of platinum-based therapies, requiring caution when considering combination therapies.

Determination of Liposomal Cisplatin by High-Performance Liquid Chromatography and Its Application in Pharmacokinetic Studies

Liposomes have been employed as carriers for antineoplastic drugs to improve delivery. We describe an HPLC-UV method for determining cisplatin levels in liposomal and biological samples, which represents an attractive alternative to the widely used flame atomic absorption spectroscopy. Liposomal cisplatin was extracted from liposomes, plasma and tissue samples by using acetonitrile and separated on a Symmetry C18 column. The mobile phase was a mixture of water, methanol and acetonitrile, and detection was performed at 254 nm. The method was linear in the range of 0.5-10 µg/mL. Using this method, cisplatin concentration was measured in plasma, kidney, liver and tumor at different times post-administration of liposomal cisplatin. This method is proved suitable for measuring the levels of cisplatin encapsulated in a liposomal system, in plasma or tissue samples of experimental animals, after intravenous administration of liposomal cisplatin. Owing to the small plasma volume employed, a complete pharmacokinetic study can be done with a single animal.

Impact of drug formulation and free platinum/cisplatin ratio on hypersensitivity reactions to cisplatin: formulation matters

WHAT IS KNOWN AND OBJECTIVE

Use of cisplatin can induce type I hypersensitivity reactions that may also be linked to the quality of the drug utilized. We observed cases of hypersensitivity that appeared to be associated with the brand of cisplatin used. The aim of this study was to compare two different brands of cisplatin in relation to type I hypersensitivity reactions.

METHODS

Brand A was used in a tertiary care teaching hospital until 2012, and use of brand B started from January 2013, when the first hypersensitivity cases were observed. Patients were categorized based on symptom. Cisplatin of both brands was analysed by high-performance liquid chromatography (HPLC) and high-resolution electrospray ionization mass spectrometry (ESI-(+)-MS) and characterized according to US Pharmacopeia.

RESULTS AND DISCUSSION

There were no cases of hypersensitivity associated with the use of cisplatin brand A, whereas four of 127 outpatients that used cisplatin brand B were affected. The two brands were in accordance with the US Pharmacopeia parameters, and there was no significant difference in the total platinum levels between the two brands when analysed by HPLC. However, high-resolution ESI-(+)-MS analyses show that brand B contains approximately 2.7 times more hydrolysed cisplatin than brand A.

WHAT IS NEW AND CONCLUSION

The increase in the hydrolysed form of cisplatin found in brand B may be the cause of the hypersensitivity reaction observed in a subset of patients. We present the first study of the quality of drugs by high-resolution ESI-(+)-MS. Drug regulatory agencies and manufacturers should consider including measurement of hydrolysed cisplatin as a quality criterion for cisplatin formulations.

Decreased P-glycoprotein is associated with the inhibitory effects of static magnetic fields and cisplatin on K562 cells

In this study, we explored the mechanism of the killing effects of a moderate-intensity static magnetic field (SMF) and cisplatin (DDP) on K562 cells. We analyzed the metabolic activity of cells, the extracellular DDP content, and P-glycoprotein (P-gp) expression after K562 cells were exposed continuously to a uniform 8.8 mT SMF for 8 h, with or without DDP. We found that SMF combined with DDP (10 µg/ml) significantly inhibited the metabolic activity of K562 cells (P < 0.05), while neither DDP nor SMF alone affected the metabolic activity of these cells. In the SMF + DDP group, extracellular DDP content was significantly reduced (P < 0.05). DDP also induced the expression of P-gp (P < 0.05). By contrast, in the SMF + DDP group, P-gp expression decreased compared with the DDP group (P < 0.05). Taken together, our results showed that 8.8 mT SMF enhanced the killing potency of DDP on K562 cells by decreasing the expression of P-gp.

Non-aggregated protamine-coated poly(lactide-co-glycolide) nanoparticles of cisplatin crossed blood-brain barrier, enhanced drug delivery and improved therapeutic index in glioblastoma cells: in vitro studies

BACKGROUND AND OBJECTIVES

Non-aggregated protamine impregnated poly(lactide-co-glycolide) nanoparticles of cisplatin (Pt-PLGA NPs) were synthesized to augment brain delivery.

METHODS AND RESULTS

The mean particle size of Pt-PLGA NPs and PLGA NPs were observed to be 173.2 ± 7.9 nm and 140 ± 10.2 nm, respectively. The Pt-PLGA NPs significantly (p < 0.05, one-way analysis of variance; ANOVA) delivered higher amount (172.41 ± 15.04 μg) of cisplatin in comparison to 110.48 ± 4.71 μg by PLGA NPs and 20.83 ± 1.65 μg by cisplatin solution across in vitro bovine brain microvessel endothelial cells. Cisplatin bearing Pt-PLGA NPs was found to be highly cytotoxic to U87 glioblastoma cells with an IC50 of 2.1 μM as compared (one-way ANOVA, p < 0.05) to PLGA NPs (3.9 μM) and cisplatin alone (13.33 μM). Impregnation with Pt enhanced the uptake of PLGA NPs in U87 glioblastoma cells as compared to PLGA NPs by following endocytosis mechanism.

CONCLUSION

Cisplatin-loaded Pt-PLGA NPs compel preclinical tumour regression study to further improve its utility against glioblastoma.

Bleomycin sulphate loaded nanostructured lipid particles augment oral bioavailability, cytotoxicity and apoptosis in cervical cancer cells

In present investigation, bleomycin sulphate loaded nanostructured lipid particles (BLM-NLPs) were constructed to enhance the oral bioavailability by overwhelming the first pass hepatic metabolism. The particles size and nanoencapsulation efficiency of BLM-NLPs were measured to be 17.4±5.4nm and 45.3±3.4%, respectively. Our studies indicated that the drug was molecularly dispersed in the lipid nanocoacervates, with amorphous geometry, without altering the chemical structure, as ascertained by spectral studies. The nanoformulation, BLM-NLPs was analyzed for dissolution testing, cytotoxicity, apoptosis and cellular uptake in human cervical cancer cell line, HeLa cells. BLM-NLPs released the drug with first order kinetic in simulated intestinal fluid (pH∼6.8±0.1), characterized by initial burst and followed by slow release. Further, an enhanced cytotoxicity (∼5.6 fold lower IC50), improved intracellular concentration (∼4.38 fold) and greater degree of apoptosis was induced by BLM-NLPs in HeLa cells, as compared to BLM alone. Moreover, BLM-NLPs also showed dose-dependent internalization, as evinced by cellular uptake study. The in vivo study indicated a significantly (P<0.0001) smaller elimination rate constant (KE), volume of distribution (Vd) and clearance rate (CLTotal) for BLM-NLPs, as compared to BLM solution in post-oral administrations. This clearly depicts the retention and stability of tailored nanoformulation in intestinal absorption pathway. In addition, our nanoformulation, BLM-NLPs documented significantly (P<0.0001)∼3.4 fold (66.20±2.57%) higher bioavailability than BLM solution (19.56±0.79%). In conclusion, our in vitro and in vivo results warrant the safety, efficacy and potency of tailored nanoformulation in clinical settings.

Ex vivo localization and permeation of cisplatin from novel topical formulations through excised pig, goat, and mice skin and in vitro characterization for effective management of skin-cited malignancies

CONTEXT

It would be advantageous to administer cisplatin topically for treatment of cutaneous malignancies.

OBJECTIVES

Present work focuses on ex vivo and in vitro characterization of proultraflexible topical formulations.

MATERIALS AND METHODS

Permeation of cisplatin through the excised pig, goat, and mice skin was quantitatively determined.

RESULTS

Data indicate that protransfersome carbopol gel (pcg) formulation clearly delayed drug permeation through skin. Permeation of cisplatin from protransfersome system (ps) formulation was enhanced by approximately 1.5 fold compared with pcg for pig and goat skin.

DISCUSSION

Localization of drug from pcg was higher and showed less permeation.

CONCLUSION

Cisplatin-loaded pcg formulation is better to treat cutaneous malignancies.

Targeted theranostic platinum(IV) prodrug with a built-in aggregation-induced emission light-up apoptosis sensor for noninvasive early evaluation of its therapeutic responses in situ

Targeted drug delivery to tumor cells with minimized side effects and real-time in situ monitoring of drug efficacy is highly desirable for personalized medicine. In this work, we report the synthesis and biological evaluation of a chemotherapeutic Pt(IV) prodrug whose two axial positions are functionalized with a cyclic arginine-glycine-aspartic acid (cRGD) tripeptide for targeting integrin αvβ3 overexpressed cancer cells and an apoptosis sensor which is composed of tetraphenylsilole (TPS) fluorophore with aggregation-induced emission (AIE) characteristics and a caspase-3 enzyme specific Asp-Glu-Val-Asp (DEVD) peptide. The targeted Pt(IV) prodrug can selectively bind to αvβ3 integrin overexpressed cancer cells to facilitate cellular uptake. In addition, the Pt(IV) prodrug can be reduced to active Pt(II) drug in cells and release the apoptosis sensor TPS-DEVD simultaneously. The reduced Pt(II) drug can induce the cell apoptosis and activate caspase-3 enzyme to cleave the DEVD peptide sequence. Due to free rotation of the phenylene rings, TPS-DEVD is nonemissive in aqueous media. The specific cleavage of DEVD by caspase-3 generates the hydrophobic TPS residue, which tends to aggregate, resulting in restriction of intramolecular rotations of the phenyl rings and ultimately leading to fluorescence enhancement. Such noninvasive and real-time imaging of drug-induced apoptosis in situ can be used as an indicator for early evaluation of the therapeutic responses of a specific anticancer drug.

A phase I study of AT-101 with cisplatin and etoposide in patients with advanced solid tumors with an expanded cohort in extensive-stage small cell lung cancer

BACKGROUND

A phase I, dose-escalation study of AT-101 with cisplatin and etoposide was conducted to determine the maximum tolerated dose (MTD)/recommended phase 2 dose (RP2D), safety and pharmacokinetics in patients with advanced solid tumors, with an expanded cohort in patients with extensive-stage small cell lung cancer (ES-SCLC) to assess preliminary activity.

METHODS

In the dose escalation portion, increasing doses of AT-101 were administered orally BID on days 1-3 along with cisplatin on day 1 and etoposide on days 1-3 of a 21 day cycle. At the RP2D, an additional 7 patients with untreated ES-SCLC were enrolled.

RESULTS

Twenty patients were enrolled in the dose-escalation cohort, and 7 patients with ES-SCLC were enrolled in the expanded cohort. The MTD/RP2D was established at AT-101 40 mg BID days 1-3 with cisplatin 60 mg/m2 and etoposide 120 mg/m2 on day 1 of a 21 day cycle with pegfilgrastim support. Two DLTs of neutropenic fever were seen at dose level 1. After the addition of pegfilgrastim, no additional DLTs were observed. Grade 3/4 treatment-related toxicities included: diarrhea, increased AST, neutropenia, hypophosphatemia, hyponatremia, myocardial infarction and pulmonary embolism. No apparent PK interactions were observed between the agents. Preliminary activity was observed with PRs in patients with ES-SCLC, high-grade neuroendocrine tumor, esophageal cancer and NSCLC.

CONCLUSIONS

AT-101 with cisplatin and etoposide is well tolerated with growth factor support. Anti-tumor activity was observed in a variety of cancers including ES-SCLC, supporting further investigation with BH-3 mimetics in combination with standard chemotherapy for ES-SCLC.

Association of ABCC2 and CDDP-Resistance in Two Sublines Resistant to CDDP Derived from a Human Nasopharyngeal Carcinoma Cell Line

Cisplatin (CDDP) is one of the most active drugs to treat nasopharyngeal carcinoma (NPC) patients. To further understand the mechanisms of CDDP-resistance in NPC, two CDDP-resistant sublines (CNE2-CDDP and CNE2-CDDP-5Fu) derived from parental NPC cell line CNE2 were established. It was found that at the IC50 level, the resistance of CNE2-CDDP and CNE2-CDDP-5Fu against CDDP was 2.63-fold and 5.35-fold stronger than that of parental CNE2, respectively. Of the four ABC transporters (ABCB1, ABCC1, ABCC2 and ABCG2) related to MDR, only ABCC2 was found to be elevated both in CDDP-resistant sublines, with ABCC2 located in nucleus of CNE2-CDDP-5Fu but not in CNE2-CDDP and parental CNE2. Further research showed that compared to untreated CNE2, the intracellular levels of CDDP were decreased by 2.03-fold in CNE2-CDDP and 2.78-fold in CNE2-CDDP-5Fu. After treatment with PSC833, a modulator of MDR associated transporters including ABCC2, the intracellular level of CDDP was increased in CDDP-resistant sublines, and the resistance to CDDP was partially reversed from 2.63-fold to 1.62-fold in CNE2-CDDP and from 5.35-fold to 4.62-fold in CNE2-CDDP-5Fu. These data indicate that ABCC2 may play an important role in NPC resistant to CDDP.

Nitric oxide synthase gene therapy enhances the toxicity of cisplatin in cancer cells

BACKGROUND

Nitric oxide (NO.) derived from donor drugs has been shown to be an effective chemosensitizer in vitro. We investigated the combination of inducible nitric oxide synthase (iNOS) gene transfer, driven by a strong constitutive promoter (cytomegalovirus; CMV) with the DNA cross-linking agent cisplatin in mouse and human tumour cell lines.

METHODS

Proof of principal experiments were performed in the radiation-induced fibrosarcoma-1 (RIF-1) murine cell line. Cells were transfected with constitutively expressed CMV/iNOS plasmid DNA using a cationic lipid vector, before exposure to cisplatin. In vivo efficacy was determined in an intradermal RIF-1 tumour model, with intraperitoneal administration of cisplatin. Additionally, treatment potential was investigated in various human tumour cell lines including human prostate (DU145 and PC3) and human colon (HT29 and HCT116) cancer cell lines. Experimental endpoints were established using western blot, Greiss test, clonogenic assay and tumour growth delay.

RESULTS

Transfection of RIF-1 tumour cells in vitro with the CMV/iNOS significantly enhanced the cytotoxicity of cisplatin (0.2-1.0 microM). In vivo transfer of CMV/iNOS by direct injection into established RIF-1 tumours caused a significant (p = 0.0027) delay in tumour growth. CMV/iNOS gene transfer in vitro resulted in the strong expression of iNOS DNA in all cell lines, and significantly increased levels of NO. in all cell lines except HCT116.

CONCLUSIONS

Significant chemosensitization of cisplatin cytotoxicity was observed in the presence of NO. derived from the overexpression iNOS. We conclude that p53 status of the various cell lines was unlikely to be responsible for cisplatin-induced apoptosis.

L-type fatty acid binding protein transgenic mouse as a novel tool to explore cytotoxicity to renal proximal tubules

A novel biomarker of renal dysfunction, liver-type fatty acid binding protein (L-FABP), which is expressed in human proximal tubules, binds to lipid peroxidation products during renal injury and is excreted into the urine. Here, we examined the usefulness of human L-FABP transgenic (Tg) mice as a tool to explore nephrotoxicity, employing two model drugs, cephaloridine and cisplatin, which are taken up by renal tubules via organic anion and cation transporters, respectively. Urinary excretion of L-FABP increased after administration of cephaloridine in most of the Tg mice, whereas glomerular filtration markers such as blood-urea-nitrogen (BUN) and plasma creatinine (CRE) were almost unchanged. Thus, L-FABP is a highly sensitive detector of the nephrotoxicity of cephaloridine. Urinary excretion of L-FABP in the Tg mice also increased after administration of cisplatin, and this increase was reduced by coadministration of cimetidine. Both BUN and CRE also increased after the cisplatin treatment, but these parameters were minimally affected by coadministration of cimetidine, suggesting that cimetidine reduces cisplatin-induced renal tubular toxicity with only a minimal effect on the glomerulus. These results indicate that the L-FABP Tg mouse should be a useful drug screening system to evaluate specifically the toxicity of transporter substrates to renal tubules.

Lentivirus-mediated RNAi silencing targeting ABCC2 increasing the sensitivity of a human nasopharyngeal carcinoma cell line against cisplatin

Background

High resistance to drug is taken as a characteristic of human tumors, which is usually mediated by multidrug resistance-associated genes. ABCC2, an ATP-binding cassette multidrug resistance transporter, is found to be expressed in a variety of human cancers. In this study the effect of a RNAi construct targeting ABCC2 on the chemosensitivity of NPC cell line CNE2 against cisplatin was investigated.

Methods

Lentiviral vectors were constructed to allow an efficient expression of anti-ABCC2 siRNA. The effective target sequence comprised nucleotides 1707–1727 of the human ABCC2 mRNA. The cell clones expressing the construct were picked and expanded, followed by identification using qRT-PCR and western blot method. As control, lentiviral vector containing invalid RNAi sequence was transfected to CNE2 cells. In vitro, cellular accumulation of cisplatin was detected by HPLC. The capacity of cellular growth and sensitivity of cells against cisplatin were detected by MTT assay. In vivo, the sensitivity of the tumor tissues against cisplatin were evaluated by transplanted CNE2 nude mice model.

Results

Two CNE2 cell clones with reduced expression of targeted ABCC2 mRNA and protein for more than 70% by qRT-PCR and western blot were established, and no differences were shown in proliferation rates compared to control CNE2 cells by growth curves analysis. In vitro the accumulation of intracellular cisplatin in these CNE2 cell clones with reduced expression of ABCC2 increased markedly, accompanied by increased sensitivity against cisplatin. In vivo, the growth of CNE2 solid tumors with a stably transfected anti-ABCC2 siRNA construct was significantly inhibited by cisplatin in transplanted nude mice model.

Conclusion

Our investigation demonstrated that lentivirus-mediated RNAi silencing targeting ABCC2 might reverse the ABCC2-related drug resistance of NPC cell line CNE2 against cisplatin.

Combined VSV oncolytic virus and chemotherapy for squamous cell carcinoma

OBJECTIVES

Vesicular stomatitis virus (VSV) is a negative-strand ribonucleic acid (RNA) virus that replicates specifically in tumor cells and has oncolytic effects in a variety of malignant tumors. We previously demonstrated recombinant VSV vectors incorporating viral fusion protein (rVSV-F) and interleukin 12 (rVSV-IL12) to have significant antitumor effects against squamous cell carcinoma (SCC) in a murine model. Here we evaluate the potential to combine a potent chemotherapeutic agent for SCC (cisplatin) with rVSV-F and rVSV-IL12 to improve efficacy.

STUDY DESIGN

In vitro, three SCC cell lines were tested using rVSV-F and rVSV-IL12 with cisplatin, monitoring viral replication and cell survival. In an orthotopic floor of mouth murine SCC model, intratumoral injections of virus combined with systemic cisplatin were tested for tumor control and animal survival.

RESULTS

In vitro, virus and cisplatin combination demonstrated rapid replication and enhanced tumor cell kill. Human keratinocytes were unaffected by virus and cisplatin. In vivo, combined rVSV-F with cisplatin reduced tumor burden and improved survival (P = .2 for both), while rVSV-IL12 monotherapy had better tumor control (P = .06) and survival (P = .024) than combination therapy.

CONCLUSIONS

Addition of cisplatin did not affect the ability of either virus to replicate in or kill murine SCC cells in vitro. In vivo, combination therapy enhancedrVSV-F antitumor activity, but diminished rVSV-IL12 antitumor activity. Combination therapy may provide useful treatment for SCC with the development of more efficient viral vectors in combination with different chemotherapy agents or immunostimulatory agents.

Analytical methodologies for the determination of cisplatin

cis-Diamminedichloroplatinum(II) (cisplatin) is a important chemotherapeutic drug for cancer treatment since 1978. Unfortunately, because of the severe side-effects like nephrotoxicity, ototoxicity, etc., they are administered in small doses at low concentration establishing the maximum limit dosage to 100 mg/m(2) (21 days). A variety of analytical methods have been proposed for the determination of cisplatin in biological fluids and tissues that permit the accurate determination at or below the part per billion level in the native sample. The purpose of the current review is to provide a systematic survey of the latest analytical techniques for the determination of cisplatin in biological samples.