Cumulative toxicities from cisplatin therapy and current cytoprotective measures

Cisplatin Nephrotoxicity: Novel Insights Into Mechanisms and Preventative Strategies

Cisplatin is a highly effective chemotherapeutic agent that has been used for more than 50 years for a variety of cancers; however, its use is limited by toxicity, including nephrotoxicity. In this in-depth review, we discuss the incidence of cisplatin-associated acute kidney injury, as well as common risk factors for its development. Cisplatin accumulates in the kidney tubules and causes AKI through various mechanisms, including DNA damage, oxidative stress, and apoptosis. We also discuss the spectrum of nephrotoxicity, including acute and chronic impairment of kidney function, electrolyte disturbances, and thrombotic microangiopathy. We discuss the limited options for the diagnosis, prevention, and management of these complications, along with factors that may impact future therapy with or without cisplatin. We conclude with directions for future research in this expanding and important area.

Bioactivity, molecular docking and anticancer behavior of pyrrolidine based Pt(II) complexes: Their kinetics, DNA and BSA binding study by spectroscopic methods

The complex [Pt(AEP)Cl₂]; C-1 (where, AEP = 1-(2-Aminoethyl) pyrrolidine) and its hydrolyzed diaqua form cis-[Pt(AEP)(H₂O)₂]²⁺; C-2 were synthesized for their bioactivity and in vitro kinetic study with bioactive thiol group (-SH) containing ligands (like; L- cysteine and N-ac-L- cysteine) for their biological importance for 'drug reservoir' activity. The Thermal Gravimetric Analysis (TGA) was executed to confirm about the weight loss due to coordinated water molecules at high temperature range. At pH 4.0, the substitution behavior of C-2 with the thiols was studied in pseudo-first order reaction condition. The interaction mechanism of thiols with complex C-2 to their corresponding thiol substituted C-3 [Pt(AEP)(L-cys)] and C-4 [Pt(AEP)(N-ac-L-cys)] (where L-cys = L-cysteine and N-ac-L-cys = N-ac-L- cysteine) were proposed from their thermodynamical activation parameters (ΔH^≠ and ΔS^≠), which were obtained from Eyring equation. DNA and BSA binding activity of the complexes C-1 to C-4 were investigated by gel electrophoresis technique, spectroscopic titration and viscosity methods. The binding activity of the complexes with DNA and BSA was evaluated using a theoretical approach molecular docking study. The drug-like nature of the complexes is supported by the prediction of activity spectra for substance (PASS) from 2D structure of the Pt(II) complexes. Structural optimization, HOMO-LUMO energy calculation, Molecular electrostatic potential surface, NBO and TD-DFT calculation were executed by using density functional theory (DFT) with Gaussian 09 software package to pre-assessment of biological activity of the complexes. DFT-based descriptors were determined from the HOMO-LUMA energy to be related with the ability of binding affinity of Pt(II) complexes towards DNA and BSA to the formation of their corresponding adducts. The anticancer property of the design complexes were examined on HCT116 (colorectal carcinoma) cancer cell lines and as well as human normal cell NKE (Normal Kidney Epithelial) and compared with the recognised anticancer drug cisplatin. The Reactive Oxygen Species (ROS) production was assessed by DCFDA assay in presence of the Pt(II) complexes.

Flavonoids of Haloxylon salicornicum (Rimth) prevent cisplatin-induced acute kidney injury by modulating oxidative stress, inflammation, Nrf2, and SIRT1

Cisplatin (CIS) is an effective chemotherapeutic drug used for the treatment of many types of cancers, but its use is associated with adverse effects. Nephrotoxicity is a serious side effect of CIS and limits its therapeutic utility. Haloxylon salicornicum is a desert shrub used traditionally in the treatment of inflammatory disorders, but neither its flavonoid content nor its protective efficacy against CIS nephrotoxicity has been investigated. In this study, seven flavonoids were isolated from H. salicornicum methanolic extract (HSE) and showed in silico binding affinity with NF-κB, Keap1, and SIRT1. The protective effect of HSE against CIS nephrotoxicity was investigated. Rats received HSE (100, 200, and 400 mg/kg) for 14 days followed by a single injection of CIS. The drug increased Kim-1, BUN, and creatinine and caused multiple histopathological changes. CIS-administered rats showed an increase in renal ROS, MDA, NO, TNF-α, IL-1β, and NF-κB p65. HSE prevented tissue injury, and diminished ROS, NF-κB, and inflammatory mediators. HSE enhanced antioxidants and Bcl-2 and downregulated pro-apoptosis markers. These effects were associated with downregulation of Keap1 and microRNA-34a, and upregulation of SIRT1 and Nrf2/HO-1 signaling. In conclusion, H. salicornicum is rich in flavonoids, and its extract prevented oxidative stress, inflammation, and kidney injury, and modulated Nrf2/HO-1 and SIRT1 signaling in CIS-treated rats.

The possible beneficial impacts of evodiamine on hepatotoxicity induced by cisplatin

In this, it was aimed to determine the possible beneficial effects of evodiamine on hepatotoxicity induced by experimental cisplatin administration in rats. For this purpose, experimental animals were divided into four groups (n=6). Groups were designed as control, evodiamine (EVO), cisplatin (CIS), and evodiamine+cisplatin (EVO+CIS) groups. All experimental processes were applied according to rules of ethical. Rats were sacrificed by high-dose anesthesia. Considering the biochemical results of this study, it can be said that lipid peroxidation level increased and antioxidant enzyme activities decreased in the CIS group comparing to control and only EVO groups. But in the EVO+CIS group, antioxidant activities increased and lipid peroxidation decreased. Moreover, immunohistochemically caspase 8 and TNF-α expressions were severe in the CIS group, whereas, in the EVO+CIS group, these expressions attenuated. According to all our findings, it can be expressed that evodiamine has beneficial effects against hepatotoxicity induced by experimental cisplatin administration.

Factors Affecting the Stability of Platinum(II) Complexes with 1,2,4-Triazolo[1,5-a]pyrimidine Derivatives and Tetrahydrothiophene-1-Oxide or Diphenyl Sulfoxide

The platinum(II) complexes of general formula [PtCl₂(dstp)(S-donor)] were dstp 5,7-dimethyl-1,2,4-triazolo[1,5-a]-pyrimidine (dmtp), 5,7-ditertbutyl-1,2,4-triazolo[1,5-a]pyrimidine (dbtp), 5-methyl-7-isobutyl-1,2,4-triazolo[1,5-a]pyrimidine (ibmtp) or 5,7-diphenyl-1,2,4-triazolo[1,5-a]pyrimidine (dptp), whereas S-tetrahydrothio-phene-1-oxide (TMSO) or diphenyl sulfoxide (DPSO) were synthesized in a one-pot reaction. Here, we present experimental data (¹H, ¹³C, ¹⁵N, ¹⁹⁵Pt NMR, IR, X-ray) combined with density functional theory (DFT) computations to support and characterize structure–spectra relationships and determine the geometry of dichloride platinum(II) complexes with selected triazolopyrimidines and sulfoxides. Based on the experimental and theoretical data, factors affecting the stability of platinum(II) complexes have been determined.

Conventional Chemotherapy Nephrotoxicity

Conventional chemotherapies remain the mainstay of treatment for many malignancies. Kidney complications of these therapies are not infrequent and may have serious implications for future kidney function, cancer treatment options, eligibility for clinical trials, and overall survival. Kidney adverse effects may include acute kidney injury (via tubular injury, tubulointerstitial nephritis, glomerular disease and thrombotic microangiopathy), long-term kidney function loss and CKD, and electrolyte disturbances. In this review, we summarize the kidney complications of conventional forms of chemotherapy and, where possible, provide estimates of incidence, and identify risk factors and strategies for kidney risk mitigation. In addition, we provide recommendations regarding kidney dose modifications, recognizing that these adjustments may be limited by available supporting pharmacokinetic and clinical outcomes data. We discuss management strategies for kidney adverse effects associated with these therapies with drug-specific recommendations. We focus on frequently used anticancer agents with established kidney complications, including platinum-based chemotherapies (cisplatin, carboplatin, oxaliplatin), cyclophosphamide, gemcitabine, ifosfamide, methotrexate and pemetrexed, among others.

Peripheral Nervous System Involvement in Non-Primary Pediatric Cancer: From Neurotoxicity to Possible Etiologies

Peripheral neuropathy is a well described complication in children with cancer. Oncologists are generally well aware of the toxicity of the main agents, but fear the side effects of new drugs. As chemotherapeutic agents have been correlated with the activation of the immune system such as in Chemotherapy Induced Peripheral Neuropathy (CIPN), an abnormal response can lead to Autoimmune Peripheral Neuropathy (APN). Although less frequent but more severe, Radiation Induced Peripheral Neuropathy may be related to irreversible peripheral nervous system (PNS). Pediatric cancer patients also have a higher risk of entering a Pediatric Intensive Care Unit for complications related to therapy and disease. Injury to peripheral nerves is cumulative, and frequently, the additional stress of a malignancy and its therapy can unmask a subclinical neuropathy. Emerging risk factors for CIPN include treatment factors such as dose, duration and concurrent medication along with patient factors, namely age and inherited susceptibilities. The recent identification of individual genetic variations has advanced the understanding of physiopathological mechanisms and may direct future treatment approaches. More research is needed on pharmacological agents for the prevention or treatment of the condition as well as rehabilitation interventions, in order to allow for the simultaneous delivery of optimal cancer therapy and the mitigation of toxicity associated with pain and functional impairment. The aim of this paper is to review literature data regarding PNS complications in non-primary pediatric cancer.

Synthesis, Characterization and Antiproliferative Evaluation of Pt(II) and Pd(II) Complexes with a Thiazine-Pyridine Derivative Ligand

Chemical, pharmacological, and clinical research on anticancer coordination complexes has led to noteworthy anticancer drugs such as cisplatin, carboplatin and oxaliplatin. Although these compounds are effective chemotherapeutic agents in the treatment of different tumors, they are associated with high toxicity and numerous side effects. Several studies have shown that the range of platinum complexes with antitumor activity is not limited to structural analogs of cisplatin. Therefore, the development of convenient anticancer drugs that can be effectively used for the treatment of human tumors has become the main goal of most research groups in this field. In this sense, active platinum complexes without NH groups, transplatinum complexes, multinuclear complexes, cationic complexes, and several classes of palladium(II) complexes have emerged. Herein, the synthesis and characterization of two Pt(II) or Pd(II) complexes with PyTz (2-(2-pyridyl)iminotetrahydro-1,3-thiazine), a thiazine derivative ligand, with the formula [MCl₂(PyTz)]·C₂H₆O (M = Pt(II) or Pd(II)) were reported. The potential anticancer ability of both complexes was evaluated in epithelial cervix carcinoma HeLa, human ovary adenocarcinoma SK-OV-3, human histiocytic lymphoma U-937, and human promyelocytic leukemia HL-60 cell lines. Interestingly, the Pt(II) complex showed great cytotoxic potential against all tumor cell lines tested, whereas the Pd(II) complex displayed slight antitumor actions.

Further Approaches in the Design of Antitumor Agents with Response to Cell Resistance: Looking toward Aza Crown Ether-dtc Complexes

The dianionic aza crown ether-dtc N,N'-bis(dithiocarbamate)-1,10-diaza-18-crown-6 (L^2-) is a versatile ligand capable of yielding binuclear complexes with group 10 elements, also known as Ni-triade, [μ-(κ²-S,-S'-L)M₂(PPh₃)₄]Cl₂ (M = Pd (1), Pt (2)), [μ-(κ²-S,-S'-L)M₂(PPh₃)₄](BPh₄)₂ (M = Pd (3), Pt (4)), and μ-(κ-S,-S'-L)Ni₂(PPh₃)₂Cl₂ (5), and has proven to be an excellent option to the design of metal-based drugs able to provide multiple response to cell resistance. Palladium and platinum complexes, 1 and 2, were tested for cytotoxicity in the human cervix carcinoma cell line HeLa-229, the human ovarian carcinoma cell line A2780, and the cisplatin-resistant mutant A2780cis, finding significant activity toward all three cancer cell lines, with low micromolar IC₅₀ values, comparable to cisplatin. Markedly, against the cisplatin resistant cell line A2780cis, compound 2 exhibits better cytotoxic activity than the clinical drug (IC₅₀ = 2.3 ± 0.2 μM for 2 versus 3.6 ± 0.5 μM for cisplatin). Moreover, an enhancement of the antitumor response is achieved when adding an equimolar amount of alkali metal chloride (NaCl or KCl) to the medium, for instance, testing compound 1 against the cisplatin-resistant A2780cis cells, the IC₅₀ decreases from 9.3 ± 0.4 to 7.4 ± 0.3 and 5.4 ± 0.1 μM, respectively, after addition of the salt solution. For the platinum derivative 2, the IC₅₀ improves by ca. 40% reaching 1.3 ± 0.1 μM when potassium chloride is added. Likewise, the resistant factor found for 2 (RF = 1) confirms that this complex circumvents cisplatin-resistance in A2780cis and is improved with the addition of potassium chloride (RF = 0.65). The presence of the aza crown ether moiety as linker in the systems studied herein is a key point since, in addition to allowing and facilitating interaction with alkali metal ions, this unit is flexible enough to adapt to a variety of environments, as confirmed by the X-ray crystal structures described, where different conformations and ways to fold in are found. In order to gain insight into the electronic and structural facts involved in the interaction of complex 2 with the alkali metal ions, a DFT study was performed, and the description of the molecular electrostatic potentials (MEPs) is also presented.

Chemotherapy-induced taste and smell changes influence food perception in cancer patients

PURPOSE

Chemotherapy-induced taste and smell alterations may have a negative impact on the quality of life and nutritional status. A prominent issue when dealing with taste and smell alterations and their consequences on food behavior and well-being lies in the variation arising from individual differences in chemosensory perceptions. The main aim of this study was to examine the effect of individuals' variation in the severity of taste and smell alterations relative to the stage of chemotherapy on self-reported food behavior and food perception.

METHODS

Eighty-nine cancer patients completed a questionnaire subdivided into two parts: a chemosensory part that allowed classification of patients in three groups ("no alterations," "moderate alterations," and "severe alterations") and a food behavior part.

RESULTS

The results highlighted a negative impact of chemosensory alterations on food perception. Compared with patients without taste and smell alterations, patients with severe chemosensory alterations reported significantly more frequent food perception problems, including modification of the perceived taste of food, finding bad taste in all food, and being unable to perceive food taste. Whereas 72% of patients with severe alterations were in late stage, only 37% of patients were in late stage in the no alterations group, indicating an effect of the treatment stage on taste and smell alterations.

CONCLUSION

Our results underlie the importance of providing specific attention to the severity of chemotherapy-induced taste and smell alterations and considering the individual differences among patients for a better nutritional management.

Bismuth Porphyrin Antagonizes Cisplatin-Induced Nephrotoxicity via Unexpected Metallothionein-Independent Mechanisms

Cisplatin (CDDP) has been a highly successful anticancer drug in cancer therapy; however, its further application suffers severe nephrotoxicity. Herein, we identify bismuth tetraphenylporphyrinate [Bi(TPP)] as a potent protective agent against CDDP-induced nephrotoxicity. Bi(TPP) attenuates CDDP-induced acute kidney injury and prevents the death of mice exposed to a lethal dose of CDDP. The protective potency of bismuth porphyrin complexes could be optimized by varying lipophilic TPP ligands with ideal ClogP values of 8–14. Unexpectedly, Bi(TPP) exhibited a protective role via metallothionein-independent pathways, i.e., maintenance of redox homeostasis and energy supplement, elimination of accumulated platinum in the kidney, and inactivation of caspases cascade in apoptotic pathway. Significantly, Bi(TPP) does not compromise the antitumor activity of CDDP in the orthotopic tumor xenograft mouse model. These findings suggest that Bi(TPP) could be incorporated into current CDDP-based cancer therapy as a nephroprotective agent.

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Bi(TPP), a potent nephroprotectant against cisplatin-induced toxicity, is disclosed

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Protective potency of Bi(TPP) could be modulated by varying lipophilic TPP ligands

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Bi(TPP) ameliorates cisplatin-induced renal damage via multiple mechanisms

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Combined therapy with Bi(TPP) does not compromise the antitumor efficacy of cisplatin

Overview of cisplatin-induced neurotoxicity and ototoxicity, and the protective agents

Cisplatin has dramatically improved the survival rate of cancer patients, but it has also increased the prevalence of hearing and neurological deficits in this population. Cisplatin induces ototoxicity, peripheral (most prevalent) and central (rare) neurotoxicity. This review addresses the ototoxicity and the neurotoxicity associated with cisplatin-based chemotherapy, providing an integrated view of the potential protective agents that have been evaluated in vitro, in vivo and in clinical trials, their targets and mechanisms of protection and their effects on the antitumor activity of cisplatin. So far, the findings are insufficient to support the use of any oto- or neuroprotective agent before, during or after cisplatin chemotherapy. Despite their promising effects in vitro and in animal studies, many agents have not been evaluated in clinical trials. Additionally, the clinical trials have limitations concerning the sample size, controls, measurement, heterogeneous groups, several arms of treatment, short follow-up or no blinding. Besides that, for most agents, the effects on the antitumor activity of cisplatin have not been evaluated in tumor-bearing animals, which discourages clinical trials. Further well-designed randomized controlled clinical trials are necessary to definitely demonstrate the effectiveness of the oto- or neuroprotective agents proposed by animal and in vitro studies.

Cisplatin: The first metal based anticancer drug

Cisplatin or (SP-4-2)-diamminedichloridoplatinum(II) is one of the most potential and widely used drugs for the treatment of various solid cancers such as testicular, ovarian, head and neck, bladder, lung, cervical cancer, melanoma, lymphomas and several others. Cisplatin exerts anticancer activity via multiple mechanisms but its most acceptable mechanism involves generation of DNA lesions by interacting with purine bases on DNA followed by activation of several signal transduction pathways which finally lead to apoptosis. However, side effects and drug resistance are the two inherent challenges of cisplatin which limit its application and effectiveness. Reduction of drug accumulation inside cancer cells, inactivation of drug by reacting with glutathione and metallothioneins and faster repairing of DNA lesions are responsible for cisplatin resistance. To minimize cisplatin side effects and resistance, combination therapies are used and have proven more effective to defect cancers. This article highlights a systematic description on cisplatin which includes a brief history, synthesis, action mechanism, resistance, uses, side effects and modulation of side effects. It also briefly describes development of platinum drugs from very small cisplatin complex to very large next generation nanocarriers conjugated platinum complexes.

Dinuclear platinum(II) complexes of imidazophenanthroline-based bridging ligands as potential anticancer agents: synthesis, characterization, and in vitro cytotoxicity studies

The synthesis and characterization of the dinucleating ligands 1,2-bis(2-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)phenoxy)ethane (L1) and 1,2-bis(2-(1H-imidazo[4,5-f][1, 10]phenanthrolin-2-yl)phenoxy)hexane (L2) and their dinuclear complexes [Pt₂(L1)Cl₄] (1) and [Pt₂(L2)Cl₄] (2) and the in vitro cytotoxicity of the complexes against HeLa, HepG2, and MCF-7 cell lines are reported. Ligand L1 crystallizes in the orthorhombic system with the space group Pbca. The complexes 1 and 2 undergo aquation following first-order kinetics. The MTT and trypan blue assays indicate higher cytotoxicity of the complexes towards the HepG2 and MCF-7 cell lines compared to cisplatin. The AO/EB assay and flow cytometry by Annexin V alexa fluor^®488/PI double staining assay demonstrate distinct morphological changes of apoptosis in a dose dependent manner. The cell cycle analysis shows a marked decrease in the DNA content in the G0/G1 phase with an increase in the G2/M phase on increasing the concentration of the complexes. The potential of the complexes as anticancer agents is demonstrated by their antiproliferative activity on the cell lines. The complexes interact with the major groove of DNA through H-bonding between the imidazole N-H protons and the nucleotide residues DC`21/N4 (cytosine) for complex 1 and DT`7/O2 (thymine) and DT`19/O2 (thymine) for complex 2, with the binding energy of - 1.98 and - 4.45 kcal/mol, respectively. Dinuclear Pt(II) complexes of imidazophenanthroline-based dinucleating ligands exhibit antiproliferative activity against HeLa, HepG2, and MCF-7 cell lines.

Role of epigenetic mechanisms in cisplatin-induced toxicity

Cisplatin (CDDP) is a highly effective antineoplastic agent, widely used in the treatment of various malignant tumors. However, its major problems are side effects associated to toxicity. Considerable inter-individual differences have been reported for CDDP-induced toxicity due to genetic and epigenetic factors. Genetic causes are well described; however, epigenetic modifications are not fully addressed. In the last few years, many evidences were found linking microRNA to the development of CDDP-mediated toxicity, particularly nephrotoxicity. In this review, we described how genetic and epigenetic modifications can be important determinants for the development of toxicity in patients treated with CDDP, and how these alterations may be interesting biomarkers for monitoring toxicity induced by CDDP. Considering the validation in different studies, we suggest that miR-34a, -146b, -378a, -192, and -193 represent an attractive study group to evaluate potential biomarkers to detect CDDP-related nephrotoxicity.

Involvement of cytochrome P450 in cisplatin treatment: implications for toxicity

PURPOSE

The aim of this study is to evaluate the relationship between the CYP450 enzyme family and cisplatin toxicity.

METHODS

This article examined a collection of studies suggesting that CYP450 enzymes may influence cisplatin toxicity. We performed a narrative mini-review.

RESULTS

The studies review showed that CYP450 enzymes have an important role in drug-induced hepatotoxicity and nephrotoxicity, mainly CYP2E1 and CYP4A11. The studies also suggested that the cisplatin and CYP2E1 interaction leads to the generation of reactive oxygen species (ROS) and other oxidants resulting in renal injury; and that ROS generated by both the use of cisplatin and by the CYP2E1 increases tissue damage, induces apoptosis, and causes liver failure.

CONCLUSIONS

We observed that there is an important relationship between CYP450 and cisplatin, involving increased toxicity. However, the possible mechanisms described for the involvement of CYP450 enzymes in nephrotoxicity and hepatotoxicity induced by cisplatin need to be confirmed by further studies. Therefore, there is a need for a deeper investigation focusing on cisplatin toxicity mediated by CYP450 enzymes, which would undoubtedly contribute to a better understanding of the mechanisms that have been implicated so far.

Bis(thiosemicarbazone) Complexes of Cobalt(III). Synthesis, Characterization, and Anticancer Potential

Nine bis(thiosemicarbazone) (BTSC) cobalt(III) complexes of the general formula [Co(BTSC)(L)2]NO3 were synthesized, where BTSC = diacetyl bis(thiosemicarbazone) (ATS), pyruvaldehyde bis(thiosemicarbazone) (PTS), or glyoxal bis(thiosemicarbazone) (GTS) and L = ammonia, imidazole (Im), or benzylamine (BnA). These compounds were characterized by multinuclear NMR spectroscopy, mass spectrometry, cyclic voltammetry, and X-ray crystallography. Their stability in phosphate-buffered saline was investigated and found to be highly dependent on the nature of the axial ligand, L. These studies revealed that complex stability is primarily dictated by the axial ligand following the sequence NH3 > Im > BnA. The cellular uptake and cytotoxicity in cancer cells were also determined. Both the cellular uptake and cytotoxicity were significantly affected by the nature of the equatorial BTSC. Complexes of ATS were taken up much more effectively than those of PTS and GTS. The cytotoxicity of the complexes was correlated to that of the free ligand. Cell uptake and cytotoxicity were also determined under hypoxic conditions. Only minor differences in the hypoxia activity and uptake were observed. Treatment of the cancer cells with the copper-depleting agent tetrathiomolybdate decreased the cytotoxic potency of the complexes, indicating that they may operate via a copper-dependent mechanism. These results provide a structure-activity relationship for this class of compounds, which may be applied for the rational design of new cobalt(III) anticancer agents.

Chitosan Nanolayered Cisplatin-Loaded Lipid Nanoparticles for Enhanced Anticancer Efficacy in Cervical Cancer

In this study, cisplatin (CDDP)-loaded chitosan-coated solid lipid nanoparticles (SLN) was successfully formulated to treat HeLa cervical carcinoma. The formulation nanoparticles were nanosized and exhibited a controlled release of drug in physiological conditions. The blank nanoparticles exhibited an excellent biocompatibility profile indicating its suitability for cancer targeting. The incorporation of CDDP in SLN remarkably increased the cancer cell death as evident from the MTT assay. Importantly, CDDP-loaded chitosan-coated SLN (CChSLN) significantly (P < 0.05) decreased the viability of cancer cells even at low concentration. The higher cytotoxicity potential of CChSLN was attributed to the higher cellular uptake as well as the sustained drug release manner in comparison with CSLN. Consistent with the cytotoxicity assay, CChSLN showed the lowest IC50 value of 0.6125 μg/ml while CSLN presented 1.156 μg/ml. CChSLN showed a significantly higher apoptosis in cancer cells compared to that of CSLN and CDDP, which is attributed to the better internalization of nanocarriers and controlled release of anticancer drugs in the intracellular environment. Our findings suggest that this new formulation could be a promising alternative for the treatment of cervical cancers. These findings are encouraging us to continue our research, with a more extended investigation of cellular response in real time and in animal models.

In vitro evaluation of folic acid-conjugated redox-responsive mesoporous silica nanoparticles for the delivery of cisplatin

The use of cisplatin(IV) prodrugs for the delivery of cisplatin have gained significant attention, because of their low toxicity and reactivity. Recent studies have shown that targeted cisplatin(IV)-prodrug nanoparticle-based delivery systems can improve the internalization of the cisplatin(IV) prodrug. We hypothesized that folic acid-conjugated mesoporous silica nanoparticles (MSNs) containing cisplatin(IV) prodrug could target cancer cells that overexpress the folate receptor and deliver the active cisplatin drug upon intracellular reduction. To prove this hypothesis, internalization and localization studies in HeLa cancer cells were performed using flow cytometry and confocal microscopy. The ability of MSNs to escape from the endolysosomal compartments, the formation of DNA adducts, and the cytotoxic effects of the MSNs were also evaluated. Our results confirmed that this MSN-based delivery platform was capable of delivering cisplatin into the cytosol of HeLa cells, inducing DNA adducts and subsequent cell death.

Using zebrafish models of leukemia to streamline drug screening and discovery

Current treatment strategies for acute leukemias largely rely on nonspecific cytotoxic drugs that result in high therapy-related morbidity and mortality. Cost-effective, pertinent animal models are needed to link in vitro studies with the development of new therapeutic agents in clinical trials on a high-throughput scale. However, targeted therapies have had limited success moving from bench to clinic, often due to unexpected off-target effects. The zebrafish has emerged as a reliable in vivo tool for modeling human leukemia. Zebrafish genetic and xenograft models of acute leukemia provide an unprecedented opportunity to conduct rapid, phenotype-based screens. This allows for the identification of relevant therapies while simultaneously evaluating drug toxicity, thus circumventing the limitations of target-centric approaches.

Renal epithelial gene expression profile and bismuth-induced resistance against cisplatin nephrotoxicity

Nephrotoxicity is the most important dose-limiting factor in cisplatin based anti-neoplastic treatment. Pretreatment with bismuth salts, used as pharmaceuticals to treat gastric disorders, has been demonstrated to reduce cisplatin-induced renal cell death in clinical settings and during in vivo and in vitro animal experiments. To investigate the genomic basis of this renoprotective effect, we exposed NRK-52E cells, a cell line of rat proximal tubular epithelial origin, to 33 mM Bi3for 12 hours, which made them resistant to cisplatin-induced apoptosis. Differentially expressed genes in treated and untreated NRK-52E cells were detected by subtraction PCR and microarray techniques. Genes found to be down regulated (0.17/0.31-times) were cytochrome c oxidase subunit I, BAR (an apoptosis regulator), heat-shock protein 70-like protein, and three proteins belonging to the translation machinery (ribosomal proteins S7 and L17, and S1, a member of the elongation factor 1-alpha family). The only up-regulated gene was glutathione Stransferase subunit 3A (1.89-times). Guided by the expression levels of these genes, it may be possible to improve renoprotective treatments during anti-neoplastic therapies.

Carvedilol protects the kidneys of tumor-bearing mice without impairing the biodistribution or the genotoxicity of cisplatin

Cisplatin (Cisp) is an effective antitumor drug; however, it causes severe nephrotoxicity. Minimization of renal toxicity is essential, but the interference of nephroprotective agents, particularly antioxidants, with the antitumor activity of cisplatin is a general concern. We have recently demonstrated that the anti-hypertensive and antioxidant drug carvedilol (CV) protects against the renal damage and increases the survival of tumor-bearing mice without impairing the tumor reduction by cisplatin. So far, reports on the antioxidant mechanism of CV are controversial and there are no data on the impact of CV on the antitumor mechanisms of cisplatin. Therefore, this study addresses the effect of CV on mechanisms underlying the tumor control by cisplatin. CV did not interfere with the biodistribution or the genotoxicity of cisplatin. We also addressed the antioxidant mechanisms of CV and demonstrated that it does not neutralize free radicals, but is an efficient chelator of ferrous ions that are relevant catalyzers in cisplatin nephrotoxicity. The present data suggest that oxidative damage and genotoxicity play different roles in the toxicity of cisplatin on kidneys and tumors and therefore, some antioxidants might be safe as chemoprotectors. Altogether, our studies provide consistent evidence of the beneficial effect of CV on animals treated with cisplatin and might encourage clinical trials.

Bio-inspired cisplatin nanocarriers for osteosarcoma treatment

Cisplatin nanocarriers with zwitterionic phosphorylcholine corona were developed for osteosarcoma treatment.

Development of Alendronate-conjugated Poly (lactic-co-glycolic acid)-Dextran Nanoparticles for Active Targeting of Cisplatin in Osteosarcoma

In this study, we developed a novel poly (lactic-co-glycolic acid)-dextran (PLD)-based nanodelivery system to enhance the anticancer potential of cisplatin (CDDP) in osteosarcoma cells. A nanosized CDDP-loaded PLGA-DX nanoparticle (PLD/CDDP) controlled the release rate of CDDP up to 48 h. In vitro cytotoxicity assay showed a superior anticancer effect for PLD/CDDP and with an appreciable cellular uptake via endocytosis-mediated pathways. PLD/CDDP exhibited significant apoptosis of MG63 cancer cells compared to that of free CDDP. Approximately ~25% of cells were in early apoptosis phase after PLD/CDDP treatment comparing to ~15% for free CDDP after 48h incubation. Similarly, PLD/CDDP exhibited ~30% of late apoptosis cells comparing to only ~8% for free drug treatment. PLD/CDDP exhibited significantly higher G2/M phase arrest in MG63 cells than compared to free CDDP with a nearly 2-fold higher arrest in case of PLD/CDDP treated group (~60%). Importantly, PLD/CDDP exhibited a most significant anti-tumor activity with maximum tumor growth inhibition. The superior inhibitory effect was further confirmed by a marked reduction in the number of CD31 stained tumor blood vessels and decrease in the Ki67 staining intensity for PLD/CDDP treated animal group. Overall, CDDP formulations could provide a promising and most effective platform in the treatment of osteosarcoma.

Effect of Silymarin Administration on Cisplatin Nephrotoxicity: Report from A Pilot, Randomized, Double-Blinded, Placebo-Controlled Clinical Trial

Despite several introduced preventive modalities, cisplatin nephrotoxicity remains a clinical problem. Some in vitro and in vivo studies have addressed the protective effects of silymarin against cisplatin nephrotoxicity. This study evaluated the effects of silymarin administration on cisplatin nephrotoxicity as the first human study. During this pilot, randomized, double-blinded, placebo-controlled clinical trial, the effect of oral silymarin 420 mg daily in three divided doses starting 24-48 h before the initiation of cisplatin infusion and continuing to the end of three 21-day cisplatin-containing chemotherapy courses on cisplatin-induced renal electrolytes wasting and kidney function were assessed. Cisplatin-associated acute kidney injury (AKI) occurred in 8% of the patients. Urine neutrophil gelatinase-associated lipocalin to urine creatinine ratio (NGAL/Cr) and urinary magnesium and potassium wasting increased significantly after cisplatin infusion in both groups. Significant positive correlation was found between cumulative dose of cisplatin and urine NGAL/Cr after three courses of cisplatin infusion. Incidence of AKI and the magnitude of urinary magnesium and potassium wasting did not differ between silymarin and placebo groups. No adverse reaction was reported by silymarin administration. Prophylactic administration of conventional form of silymarin tablets could not prevent cisplatin-induced urine electrolyte wasting or renal function impairment.

Thyroid-stimulating hormone (TSH)-armed polymer–lipid nanoparticles for the targeted delivery of cisplatin in thyroid cancers: therapeutic efficacy evaluation

Thyroid-stimulating hormone (TSH)-conjugated polymer–lipid hybrid nanoparticles (TPLHC) were developed for the targeted delivery of cisplatin (CDDP) in thyroid cancers.

The oligometastatic state - separating truth from wishful thinking

The oligometastatic paradigm implies that patients who develop a small number of metastatic lesions might achieve long-term survival if all these lesions are ablated with surgery or stereotactic radiotherapy. Clinical data indicate that the number of patients with oligometastatic disease receiving aggressive treatment is increasing rapidly. We examine the key evidence supporting or refuting the existence of an oligometastatic state. Numerous single-arm studies suggest that long-term survival is 'better-than-expected' after ablative treatment. However, the few studies with adequate controls raise the possibility that this long-term survival might not be due to the treatments themselves, but rather to the selection of patients based on favourable inclusion criteria. Furthermore, ablative treatments carry a risk of harming healthy tissue, yet the risk-benefit ratio cannot be quantified if the benefits are unmeasured. If the strategy of treating oligometastases is to gain widespread acceptance as routine clinical practice, there should be stronger evidence supporting its efficacy.

Antioxidant and antigenotoxic role of recombinant human erythropoeitin against alkylating agents: Cisplatin and mitomycin C in cultured Vero cells

Cisplatin (CDDP) and mitomycin C (MMC), two alkylating agents used against various solid tumours, are a common source of acute kidney injury. Thus, strategies for minimizing CDDP and MMC toxicity are of a clinical interest. In this study, we aimed to investigate the protective role of recombinant human erythropoietin (rhEPO) against oxidative stress and genotoxicity induced by CDDP and MMC in cultured Vero cells. Three types of treatments were performed: (i) cells were treated with rhEPO 24 h before exposure to CDDP/MMC (pre-treatment), (ii) cells were treated with rhEPO and CDDP/MMC simultaneously (co-treatment), (iii) cells were treated with rhEPO 24 h after exposure to CDDP/MMC (post-treatment). Our results showed that rhEPO decreased the reactive oxygen species levels, the malondialdehyde levels and ameliorated glutathione (reduced and oxidized glutathione) modulation induced by CDDP and MMC in cultured Vero cells. Furthermore, rhEPO administration prevented alkylating agents-induced DNA damage accessed by comet test. Altogether, our results suggested a protective role of rhEPO, against CDDP- and MMC-induced oxidative stress and genotoxicity, especially in pre-treatment condition.

Risk factors for hematological toxicity of chemotherapy for bone and soft tissue sarcoma

The aim of this study was to assess chemotherapy treatment characteristics, neutropenic event occurrence and related risk factors in bone and soft tissue sarcoma patients in China. Knowledge of such risk factors aids healthcare providers in focusing resources on those who are at most risk and targeting prophylactic colony-stimulating factors (CSFs) for those patients. The study included 113 children and adults with different types of sarcoma who had been treated with neoadjuvant chemotherapy for bone and soft tissue sarcoma in order to identify risk factors for hematological toxicity of chemotherapy for bone and soft tissue sarcoma. Risk factors were determined using multivariate logistic regression analysis. Factors such as age <20 years, Karnofsky Performance Status Scale (KPS) score <60, malnutrition, number of previous chemotherapies >3 and combination therapy with >3 drugs were significantly associated with occurrence of grade III/IV neutropenia, suggestive of severe bone marrow suppression. Patients with such characteristics are at most risk of severe bone marrow suppression, and preventing discontinuation of treatment would be valuable for treating patients more effectively.

Cisplatin-loaded core cross-linked micelles: comparative pharmacokinetics, antitumor activity, and toxicity in mice

Polymer micelles with cross-linked ionic cores are shown here to improve the therapeutic performance of the platinum-containing anticancer compound cisplatin. Biodistribution, antitumor efficacy, and toxicity of cisplatin-loaded core cross-linked micelles of poly(ethylene glycol)-b-poly(methacrylic acid) were evaluated in a mouse ovarian cancer xenograft model. Cisplatin-loaded micelles demonstrated prolonged blood circulation, increased tumor accumulation, and reduced renal exposure. Improved antitumor response relative to free drug was seen in a mouse model. Toxicity studies with cisplatin-loaded micelles indicate a significantly improved safety profile and lack of renal abnormalities typical of free cisplatin treatment. Overall, the study supports the fundamental possibility of improving the potential of platinum therapy using polymer micelle-based drug delivery.

In vitro anticancer activity of cis-diammineplatinum(II) complexes with β-diketonate leaving group ligands

Five cationic platinum(II) complexes of general formula, [Pt(NH(3))(2)(β-diketonate)]X are reported, where X is a noncoordinating anion and β-diketonate = acetylacetonate (acac), 1,1,1,-trifluoroacetylacetonate (tfac), benzoylacetonate (bzac), 4,4,4-trifluorobenzoylacetonate (tfbz), or dibenzoylmethide (dbm), corresponding, respectively, to complexes 1-5. The log P values and the stabilities of 1-5 in aqueous solution were evaluated. The phenyl ring substituents of 3-5 increase the lipophilicity of the resulting complexes, whereas the trifluoromethyl groups of 2 and 4 decrease the stability of the complexes in aqueous solution. The uptake of 1-5 in HeLa cells increases as the lipophilicity of the investigated complex increases. Cancer cell cytotoxicity studies indicate that 1 and 3 are the least active complexes whereas 2, 4, and 5 are comparable in activity to cisplatin.

Cisplatin-induced nephrotoxicity and targets of nephroprotection: an update

Cisplatin is a highly effective antitumor agent whose clinical application is limited by the inherent nephrotoxicity. The current measures of nephroprotection used in patients receiving cisplatin are not satisfactory, and studies have focused on the investigation of new possible protective strategies. Many pathways involved in cisplatin nephrotoxicity have been delineated and proposed as targets for nephroprotection, and many new potentially protective agents have been reported. The multiple pathways which lead to renal damage and renal cell death have points of convergence and share some common modulators. The most frequent event among all the described pathways is the oxidative stress that acts as both a trigger and a result. The most exploited pathways, the proposed protective strategies, the achievements obtained so far as well as conflicting data are summarized and discussed in this review, providing a general view of the knowledge accumulated with past and recent research on this subject.

Apoptosis sensitizers enhance cytotoxicity in hepatoblastoma cells

PURPOSE

Drug resistance remains a major challenge for the treatment of high-risk hepatoblastoma (HB). To enhance effectiveness of chemotherapy we modulate apoptosis in HB cells in vitro.

METHODS

Viability was monitored in HB cells (HuH6, HepT1) and fibroblasts in monolayer and spheroid cultures treated with ABT-737, obatoclax, HA14-1, and TW-37 and each in combination with CDDP, etoposide, irinotecan, paclitaxel, and DOXO in a MTT assay. Western blot analyses were performed to determine expressions of pro- and anti-apoptotic proteins.

RESULTS

Obatoclax and ABT-737 led to a dose-dependent decrease of viability in HB cells at concentrations above 0.3 μM. TW-37 and HA14-1 were less effective. ABT-737 and obatoclax had additive effects when combined with CDDP, etoposide, irinotecan, paclitaxel, or DOXO. This was also observed for fibroblast, however, for higher drug concentrations. In spheroid cultures, relative expression of Bcl-XL was increased, Bax was decreased, Mcl-1 was low, and Bcl-2 was not detected compared to 2D cultures, denoting an anti-apoptotic state in spheroids. Obatoclax and ABT-737 have overcome the resistance to CDDP. HuH6 cells have shown higher susceptability for apoptosis sensitizers than HepT1.

CONCLUSION

The data provide evidence that ABT-737 and obatoclax might improve treatment results in children with HB.

Carvedilol protects against apoptotic cell death induced by cisplatin in renal tubular epithelial cells

Cisplatin is a highly effective chemotherapeutic drug; however, its use is limited by nephrotoxicity. Studies showed that the renal injury produced by cisplatin involves oxidative stress and cell death mediated by apoptosis and necrosis in proximal tubular cells. The use of antioxidants to decrease cisplatin-induced renal cell death was suggested as a potential therapeutic measure. In this study the possible protective effects of carvedilol, a beta blocker with antioxidant activity, was examined against cisplatin-induced apoptosis in HK-2 human kidney proximal tubular cells. The mitochondrial events involved in this protection were also investigated. Four groups were used: controls (C), cisplatin alone at 25 μM (CIS), cisplatin 25 μM plus carvedilol 50 μM (CV + CIS), and carvedilol alone 50 μM (CV). Cell viability, apoptosis, caspase-9, and caspase-3 were determined. Data demonstrated that carvedilol effectively increased cell viability and minimized caspase activation and apoptosis in HK-2 cells, indicating this may be a promising drug to reduce nephrotoxicity induced by cisplatin.

Paternal treatment with cisplatin impairs reproduction of adult male offspring in rats

This study evaluated the acute and persistent effects of paternal cisplatin-treatment on progeny. Wistar male rats (45 days old) were assigned into 2 groups. Control and cisplatin (CP: 1mg/kg-d, 5 days/week, for 3 weeks, ip.). Male rats at 66 (end of treatment, acute effects evaluation) and 140 days old (after recovery period, persistent effects evaluation) were mated with females. Fetal and post-natal developments of the offspring sired by treated-male mated in both ages were evaluated, including fertility of adult male offspring. No adverse effects in fetal development or puberty onset were seen in CP offspring. However, testicular descent was delayed and postnatal growth was impaired in these animals (acute effect). Moreover, seminal vesicle weight and epididymal sperm count from adult progeny were affected (acute effects) by paternal CP-exposure. The only persistent effect found was alterations in the spermatogenesis. We conclude that paternal CP-administration during peri-puberty affects reproductive endpoints of the progeny.