Cisplatin Toxicity Research Articles

Protective Effect of Panduratin A on Cisplatin-Induced Apoptosis of Human Renal Proximal Tubular Cells and Acute Kidney Injury in Mice.

Cisplatin is an effective chemotherapy but its main side effect, acute kidney injury, limits its use. Panduratin A, a bioactive compound extracted from Boesenbergia rotunda, shows several biological activities such as anti-oxidative effects. The present study investigated the nephroprotective effect of panduratin A on cisplatin-induced renal injury. We investigated the effect of panduratin A on the toxicity of cisplatin in both mice and human renal cell cultures using RPTEC/TERT1 cells. The results demonstrated that panduratin A ameliorates cisplatin-induced renal toxicity in both mice and RPTEC/TERT1 cells by reducing apoptosis. Mice treated with a single intraperitoneal (i.p.) injection of cisplatin (20 mg/kg body weight (BW)) exhibited renal tubule injury and impaired kidney function as shown by histological examination and increased serum creatinine. Co-administration of panduratin A (50 mg/kg BW) orally improved kidney function and ameliorated renal tubule injury of cisplatin by inhibiting activation of extracellular signal-regulated kinase (ERK)1/2 and caspase 3. In human renal proximal tubular cells, cisplatin induced cell apoptosis by activating pro-apoptotic proteins (ERK1/2 and caspase 3), and reducing the anti-apoptotic protein (Bcl-2). These effects were significantly ameliorated by co-treatment with panduratin A. Interestingly, panduratin A did not alter intracellular accumulation of cisplatin. It did not alter the anti-cancer efficacy of cisplatin in either human colon or non-small cell lung cancer cell lines. The present study highlights panduratin A has a potential protective effect on cisplatin's nephrotoxicity.

INVESTIGATION OF THE NEUROPROTECTIVE EFFECT OF MELATONIN ON HIPPOCAMPAL NEURON INJURY DEVELOPING DUE TO THE NEUROTOXIC EFFECT OF CISPLATIN

Cisplatin is a widely used antineoplastic agent, but it has side effects that decrease quality of life. Its neurotoxic effects lead to cognitive disorders during or after treatment in 70% of the patients. In this study, the efficiency of melatonin to reduce cisplatin-induced toxicity was investigated. Four subject groups were established using 24 adult male Wistar Albino rats. Neurotoxicity was produced by administering intraperitoneal (ip) cisplatin on the 1st, 5th, 9th and 13th day at a dose of 4 mg/kg. Intraperitoneal melatonin was applied to the treatment group for 13 days at a dose of 10 mg/kg/day and the groups were compared. Following sacrification on the 14th day, hippocampal tissues were excised. Cisplatin toxicity and melatonin efficiency were analyzed by calculating pyknosis and edema scores. It was observed that there was no significant difference between the Sham, Mel and Cisp+Mel groups in terms of pyknosis, but a marked increase in pyknotic neurons occurred in the group which was given cisplatin (p<0.01). It was found that edema in the hippocampal tissue increased markedly in the rats which were given cisplatin, but edema scores statistically significantly decreased when melatonin was given (p<0.01). Cisplatin and melatonin influence the same oxidative and apoptotic processes in opposite directions. In our study, we examined the effects of melatonin on cisplatin-induced toxicity and concluded that melatonin showed protective action against cisplatin-induced neurotoxic effects. Our conclusion indicated that cancer patients would be exposed to fewer neurotoxic side effects when cisplatin, a widely used chemotherapeutic drug, is used in combination with melatonin.

VDAC1 as a target in cisplatin anti-tumor activity through promoting mitochondria fusion

Cisplatin is one of the most effective anti-cancer drugs, but its efficacy is limited by the development of resistance. Previous studies have shown that mitochondria play critical roles in cisplatin cytotoxicity, however, the exact mechanism of mitochondria involved in cisplatin sensitivity has not been clarified. In this study, cisplatin triggered mitochondrial oxidative stress and the decrease of mitochondria membrane potential in human cervical cancer cells. Then we screened a series of mitochondrial relevant inhibitors, including mitochondrial mPTP inhibitors DIDS and CsA, and mitochondrial respiratory complex inhibitors Rot and TTFA. Among these, only DIDS, as the inhibitor of mitochondrial outer membrane protein VDAC1, showed strong antagonism against cisplatin toxicity. DIDS mitigated cisplatin-induced MFN1-dependent mitochondrial fusion, mitochondrial dysfunction and oxidative damage. These findings demonstrated that VDAC1 may serve as a potential therapeutic target in the increase sensitivity of cisplatin, which provides an attractive pharmacological therapy to improve the effectiveness of chemotherapy.

Preventive effect of Bacillus mojavensis levan against carbon tetrachloride and cisplatin toxicity: in vivo study.

This study is the first to investigate the hepato- and nephron-preventive effect of levan from Bacillus mojavensis (BM-levan) against toxicity induced by carbon tetrachloride (CCl4) and cisplatin. Thirty-six male albino rats weighing between 230 and 250g were used for this experiment. The groups received multiples doses of BM-levan and were compared to the untreated group. The in vitro and in vivo biological potentials of BM-levan were evaluated by measuring its antioxidant capacity as well as its hepato- and nephron-protective activities in rat models. The investigations highlighted a significant in vitro antioxidant activity indicated by the radical-scavenging capacity, the reducing power, and the total antioxidant activity measurement. In addition, results demonstrate that BM-levan supplementation during 8weeks (100mg/kg body weight) significantly (p < 0.05) decreased aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities and remarkably (p < 0.05) attenuated the altered lipid profile by decreasing the levels of triglycerides (TG) and total cholesterol (TC), LDL cholesterol (LDL-C) and by enhancing the HDL cholesterol (HDL-C) content, when compared with the CCl4 group. BM-levan also reduced the content of plasma renal biomarkers (urea, creatinine, and uric acid) in the cisplatin-treated group. Moreover, BM-levan inhibited hepatic and renal oxidative stress generated by CCl4 and cisplatin administration, through the enhancement of the antioxidant catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) and the diminishment of lipid peroxidation. The harmful effects of CCl4 or cisplatin on hepatic and renal histology were found to be decreased by the addition of BM-levan. Therefore, BM-levan has proved promising for biomedical applications thanks to its in vitro and in vivo antioxidant properties.

Quinacrine ameliorated Cisplatin‐induced renal toxicity via modulation of Sirtuin‐1 and its downstream inflammatory and apoptosis pathways

Cisplatin is an effective and widely used chemotherapeutic agent, while underlying renal toxicity is a major limitation for its use. Quinacrine, is an FDA approved antimalarial agent that is known for its anti-inflammatory effect. It has been shown that quinacrine is therapeutically beneficial in cancer, lupus erythematosus and cutaneous sarcoidosis, however, its use to protect against cisplatin toxicity has not been investigated. In this study, we investigated the ameliorative effect of quinacrine against cisplatin induced renal toxicity in rats and the potential molecular mechanism of quinacrine action. Cisplatin toxicity was induced by a single intraperitoneal injection of 10 mg/kg at day 5. Reno protective effect of quinacrine was assessed by intraperitoneal injection of 10 mg/kg/day for the whole-time course of the experiment (10 days). Quinacrine increased rats’ survival rate from 50% (cisplatin group) to 87.5%, with significant decrease in relative kidney weight to body weight, serum creatinine and urea levels in addition to significant reduction in renal tissue fibrosis compared with cisplatin group. Moreover, quinacrine attenuated cisplatin-induced oxidative stress upregulation as indicated by significant decrease in renal malondialdehyde concentration and significant increase in renal total antioxidant capacity compared with cisplatin group. Mechanistically, quinacrine significantly upregulated renal tissue concentration of sirtuin-1 (Sirt-1) which significantly downregulated the inflammatory markers: Intercellular Adhesion Molecule-1 (ICAM-1) and tumor necrosis factor-α (TNF-α). In addition, quinacrine significantly prevented cisplatin-induced apoptosis as evident by decreased renal tissue expression of caspases (1, 3, 8 and 9), decreased the apoptotic proteins BAX and P53 and increased the anti-apoptotic protein BCL2 compared with cisplatin group. Altogether, this study proposes, for the first time, that quinacrine ameliorated cisplatin-induced renal toxicity via upregulation of Sirt-1, downregulation of inflammatory markers (ICAM-1 and TNF-α), restoring oxidative balance and suppressing apoptosis.

Comparisons of segment-specific toxicity of platinum-based agents and cadmium using S1, S2, and S3 cells derived from mouse kidney proximal tubules

Renal toxicants such as cisplatin and cadmium cause segment-specific damages in kidney proximal tubules. Recently, we established an in vitro experimental system for evaluating segment-specific toxicity and transport of chemicals using immortalized S1, S2, and S3 cells derived from the S1, S2, and S3 regions of mouse kidney proximal tubules. In the present study, we examined the toxicity and accumulation of cisplatin, carboplatin, oxaliplatin, and cadmium in S1, S2, and S3 cells. We found that not only cisplatin but also carboplatin and oxaliplatin exhibited higher lethal toxicity in S3 cells than in S1 and S2 cells. At sublethal doses, cisplatin showed delayed induction of Kim-1 and clusterin on days 3 and 6, which may reflect the latent renal toxicity of cisplatin in vivo. The high sensitivities of S3 cells to the platinum-based agents were not due to the high accumulation of Pt in S3 cells. Exposure to cadmium resulted in similar toxicity among these cells, suggesting that S3 cells were not sensitive to any renal toxicants. Thus, the utilization of S1, S2, and S3 cells may provide a useful tool for the in vitro evaluation of the proximal tubule segment-specific toxicity of chemicals.

Watermelon Reduces the Toxicity of Cisplatin Treatment in C57BL/6 Mice with Induced Melanoma

An alternative to reduce the undesirable effects of antineoplastic agents has been the combination of classical treatments with nutritional strategies aimed at reducing systemic toxicity without decreasing the antitumor activity of already used drugs. Within this context, this study evaluated the possible reduction of toxicity when cisplatin treatment is combined with watermelon pulp juice supplementation in C57BL/6 mice with melanoma. Watermelon is a fruit rich in vitamins, minerals, proteins, lycopene, carotene, and xanthophylls, which has shown effectiveness in the treatment of cardiovascular diseases, weight loss, urinary infections, gout, hypertension, and mutagenicity. The following parameters were analyzed: animal survival, bone marrow genotoxicity, serum creatinine and urea, histopathological features of the tumor tissue, tumor weight and volume, and weight of non-tumor tissues (kidney, liver, spleen, heart, and lung). The results showed that watermelon had no antitumor effect but reduced the toxicity of cisplatin, as demonstrated by an increase in the number of bone marrow cells and a decrease in serum creatinine and urea levels. The data suggest that watermelon pulp juice can be an alternative for reducing the side effects of antineoplastic agents.

Baseline audiological profiling of South African females with cervical cancer: an important attribute for assessing cisplatin-associated ototoxicity

BackgroundCisplatin is a popular antineoplastic agent used to treat cervical cancer in women from low and middle-income countries. Cisplatin treatment is associated with ototoxicity, often resulting in hearing loss. In light of this, it is crucial to conduct baseline audiological assessments prior to treatment initiation in order to evaluate the extent of cisplatin-associated-ototoxicity. Additionally, the identification of inherent risk factors and hearing patterns in specific patient cohorts is needed, especially in South Africa, a middle-income country characterized by the quadruple burden of disease (Human Immunodeficiency Virus (HIV), Tuberculosis (TB), Diabetes and Hypertension).MethodsThis study aimed to describe a profile of risk factors and hearing in a cohort of females with cervical cancer before cisplatin treatment commenced. A descriptive study design that included 82 cervical cancer patients, who underwent audiological evaluation prescribed for ototoxicity monitoring was conducted.ResultsAll participants (n = 82) presented with risk factors (diabetes, hypertension, HIV, and antiretroviral therapy) for cisplatin ototoxicity and/or pre-existing sensorineural hearing loss. High-frequency tinnitus was the most common otological symptom experienced by 25 (31%) participants. Fifty-nine (72%) participants presented with normal hearing, twenty-two (27%) with a sensorineural hearing loss, and 36% were diagnosed with mild hearing loss. Abnormal Distortion Product Otoacoustic Emissions (DPOAE) findings were obtained bilaterally in two participants (2.4%), in the right ear only of another two (2.4%) participants and the left ear of three participants (3.7%). Most participants (94%) had excellent word recognition scores, demonstrating an excellent ability to recognize words within normal conversational levels under optimal listening conditions. Age was significantly associated with hearing loss at all thresholds. Among the co-morbidities, an HIV positive status significantly triggered hearing loss, especially at higher frequencies.ConclusionThis study demonstrated that South African females with cervical cancer present with various co-morbidities, which may predispose them to develop cisplatin-associated -ototoxic hearing loss. Identification of these co-morbidities and hearing loss is essential for the accurate monitoring of cisplatin toxicities. Appropriate management of these patients is pivotal to reduce the adverse effects that hearing impairment can have on an individual’s quality of life and to facilitate informed decision-making regarding the commencement of cisplatin chemotherapy.

Cisplatin +/\u2212 rucaparib after preoperative chemotherapy in patients with triple-negative or BRCA mutated breast cancer

Patients with triple-negative breast cancer (TNBC) who have residual disease after neoadjuvant therapy have a high risk of recurrence. We tested the impact of DNA-damaging chemotherapy alone or with PARP inhibition in this high-risk population. Patients with TNBC or deleterious BRCA mutation (TNBC/BRCAmut) who had >2 cm of invasive disease in the breast or persistent lymph node (LN) involvement after neoadjuvant therapy were assigned 1:1 to cisplatin alone or with rucaparib. Germline mutations were identified with BROCA analysis. The primary endpoint was 2-year disease-free survival (DFS) with 80% power to detect an HR 0.5. From Feb 2010 to May 2013, 128 patients were enrolled. Median tumor size at surgery was 1.9 cm (0–11.5 cm) with 1 (0–38) involved LN; median Residual Cancer Burden (RCB) score was 2.6. Six patients had known deleterious BRCA1 or BRCA2 mutations at study entry, but BROCA identified deleterious mutations in 22% of patients with available samples. Toxicity was similar in both arms. Despite frequent dose reductions (21% of patients) and delays (43.8% of patients), 73% of patients completed planned cisplatin. Rucaparib exposure was limited with median concentration 275 (82–4694) ng/mL post-infusion on day 3. The addition of rucaparib to cisplatin did not increase 2-year DFS (54.2% cisplatin vs. 64.1% cisplatin + rucaparib; P = 0.29). In the high-risk post preoperative TNBC/BRCAmut setting, the addition of low-dose rucaparib did not improve 2-year DFS or increase the toxicity of cisplatin. Genetic testing was underutilized in this high-risk population.

Toll-like receptor 4 is activated by platinum and contributes to cisplatin-induced ototoxicity.

Toll‐like receptor 4 (TLR4) recognizes bacterial lipopolysaccharide (LPS) and can also be activated by some Group 9/10 transition metals, which is believed to mediate immune hypersensitivity reactions. In this work, we test whether TLR4 can be activated by the Group 10 metal platinum and the platinum‐based chemotherapeutic cisplatin. Cisplatin is invaluable in childhood cancer treatment but its use is limited due to a permanent hearing loss (cisplatin‐induced ototoxicity, CIO) adverse effect. We demonstrate that platinum and cisplatin activate pathways downstream of TLR4 to a similar extent as the known TLR4 agonists LPS and nickel. We further show that TLR4 is required for cisplatin‐induced inflammatory, oxidative, and cell death responses in hair cells in vitro and for hair cell damage in vivo. Finally, we identify a TLR4 small molecule inhibitor able to curtail cisplatin toxicity in vitro. Thus, our findings indicate that TLR4 is a promising therapeutic target to mitigate CIO.

Using a High Quantum Yield Fluorescent Probe with Two-Photon Excitation to Detect Cisplatin in Biological Systems.

A direct detection protocol for the anticancer drug of cisplatin is highly desirable for studying its actions and side effects. In this work, a high quantum yield fluorescent probe with two-photon excitation to detect cisplatin was designed. The probe (RD640-TC) was based on the rhodamine 640 (Rh640) fluorophore, responding to cisplatin with red fluorescence. It showed an excellent linear correlation between the fluorescence response and the concentration of cisplatin over the range of 2-50 μM, suggesting a feasible tool for convenient detection of cisplatin. RD640-TC had high fluorescence quantum yield (Φ = 0.68) and two-photon absorption properties, which made it more favorable to probe cisplatin in biological systems. We exemplified RD640-TC for the detection of cisplatin in cells and zebrafish, providing an accessible tool for in vivo tracking of cisplatin, which has great potential value for studying how cisplatin is processed at cellular level and further for facilitating the investigation into the origin of cisplatin's toxicity.

Effect of TOP2A and ERCC1 gene polymorphisms on the efficacy and toxicity of cisplatin and etoposide-based chemotherapy in small cell lung cancer patients.

IntroductionThe main treatment regimen for small cell lung cancer (SCLC) involves platinum-based chemotherapy (cisplatin or carboplatin) and etoposide. Single nucleotide polymorphisms (SNPs) in TOP2A and ERCC1 genes were tested as prognostic and predictive factors in non-small cell lung cancer (NSCLC). There are limited data about the clinical relevance of these genetic alterations in SCLC. We undertook this retrospective study to determine the influence of SNPs in TOP2A (rs34300454; rs13695; rs11540720) and ERCC1 (rs11615; rs3212986) genes on the efficiency and toxicity of chemotherapy with platinum and etoposide in SCLC Caucasian patients.Material and methodsThe studied group included 103 Caucasian SCLC patients (65 male, 38 female, median age 65 ±7.5 years). Detailed clinical-demographical data were collected and response to treatment was monitored. DNA was isolated from peripheral blood leukocytes using QIAamp DNA Mini Kit. Single nucleotide polymorphisms were analyzed using TaqMan hydrolyzing probes in real-time PCR technique on an Eco Illumina device.ResultsPatients with C/C genotype in rs13695 of the TOP2A gene had significantly lower risk of neutropenia during chemotherapy than C/T heterozygous patients (p = 0.02, χ² = 5.51, OR = 2.676, 95% CI: 1.165–6.143). Patients harbouring homozygous C/C genotype in rs3212986 of the ERCC1 gene had significantly higher risk of anaemia during chemotherapy, than heterozygous C/A patients (p = 0.045, χ² = 4.01, OR = 0.417, 95% CI: 0.175–0.991). Furthermore, heterozygous G/A genotype in rs11615 of the ERCC1 gene was associated with significant shortening of OS (9 vs. 12 months) compared to homozygous A/A genotype (p = 0.01, χ² = 6.31, HR = 1.657, 95% CI: 1.0710–2.5633).ConclusionsSNPs in ERCC1 and TOP2 genes may be associated with the toxicities and survival of SCLC patients treated with cisplatin and etoposide.

Enoxaparin prevents CXCL16/ADAM10-mediated cisplatin renal toxicity: Role of the coagulation system and the transcriptional factor NF-κB

Background and aimsC-X-C ligand 16 (CXCL16) is an exceptional chemokine that is expressed as transmembrane and soluble forms. Our aim is to shed lights on the role of CXCL16/ADAM10 (a disintegrin and metalloproteinase) in cisplatin (CP)-induced renal toxicity as well as possible protective effect of enoxaparin. Main methodsMale albino mice were injected with CP (30 mg/kg, i.p.) in the presence or absence of enoxaparin (ENOX) (5 mg/kg, i.p.). Renal toxicity markers, serum level of cystatin-c, complete blood count (CBC), prothrombin time (Pt) and tissue expression of CXCL16, ADAM10, cluster of differentiation 3 (CD3), fibrinogen, tissue factor (TF), nuclear factor-κB (NF-κB) and tumour necrosis factor α (TNF-α) were measured. Besides, serum CXCL16 and histopathology were also analyzed. Key findingsCP increased renal toxicity markers, renal expression of CXCL16/ADAM10, fibrinogen, TF and CD3 tissue expression in a time-dependent manner, and elevated serum cystatin-c, CXCL16 and tissue TNF-α, NF-κB. Alternatively, ENOX restored the deteriorated parameters and reduced tissue level of NF-κB. SignificanceThis report, for the first time, showed that soluble CXCL16 resulting from ADAM10 cleavage may recruit T-cells to the renal glomeruli and tubules in CP toxicity. Furthermore, TF and fibrin, have similar expression and location pattern like CXCL16 and ADAM10 suggesting their possible interrelation. ENOX successfully restored the deteriorated parameters suggesting it may be an effective nephroprotective adjuvant therapy.

Investigation of the antitumor activity and toxicity of cisplatin loaded pH-sensitive-pegylated liposomes in a triple negative breast cancer animal model

Over the last decade, studies showed evidence of enhanced sensitivity of triple negative breast cancer (TNBC) to DNA-damaging agents, such as cisplatin (CIS), compared to other breast cancer subtypes. Despite its high efficacy, CIS has its use limited by dose-dependent side effects, mainly nephrotoxicity and neurotoxicity. In previous studies, it has been demonstrated by our research group that the encapsulation of CIS into pH-sensitive-PEGylated liposomes (pHPL-CIS) might allow to overcome some of its side effects. In the present work, we investigated the antitumor activity and toxicity of pHPL-CIS on Balb/c nude female mice bearing MDA-MB-231 tumor, a human TNBC cell line. Treatments with free-CIS or pHPL-CIS were both administered i.v. once a week for three weeks in cumulative doses of 12 and 30 mg/kg. Treatments in the higher dose allowed for similar tumor regression at the end of the experiment, however, the treatment with pHPL-CIS allowed for an earlier appearance of the antitumor effect. Additionally, animals receiving the higher dose of free-CIS presented weight loss, hepatic degeneration and 20% mortality rate, which was not observed for animals that received the high dose of pHPL-CIS. Thus, pHPL-CIS might be considered a promising candidate for the management of TNBC.

Update results of paclitaxel and cisplatin in combination with anlotinib as first-line regimen for advanced esophageal squamous cell carcinoma (ESCC): A multicenter, single-arm, open-label phase Ⅱ clinical trial.

181 Background: The prognosis of pts with advanced ESCC remains dismal clinically. Paclitaxel and cisplatin were used as the standard first-line regimen in ESCC for almost two decades. As a novel multitarget tyrosine kinase inhibitor mainly targeting antiangiogenic single pathway, anlotinib was demonstrated to be an effective second-line monotherapy for pts with advanced or recurrent ESCC in China. Consequently, the aim of this study was to investigate the efficacy and toxicity of paclitaxel and cisplatin combined with anlotinib as first-line therapy for advanced ESCC. Methods: Pts with previously untreated metastatic or unresectable, locally advanced ESCC, who had not received (neo) adjuvant therapy/radical surgery within 6 months were recruited in this study. Eligible subjects were given paclitaxel (135mg/m2, iv, q3w) and cisplatin (60~75mg/m2, iv, d1~3, q3w) plus anlotinib (10mg, po, d1~14, q3w) for 4~6 cycles during initial therapy. For those without progressive disease, maintenance treatment was administrated with anlotinib monotherapy (10mg, po, d1~14, q3w) until progression or unacceptable toxicity. The tumor response was assessed by investigator according to RECIST version 1.1 using CT scans every two cycles. And the calculated sample size of this study was 47. The primary endpoint was PFS, secondary endpoints were safety, objective response rate (ORR), disease control rate (DCR) and duration of response (DOR). Results: From Oct 2019 to Aug 2020, 27 pts were available for efficacy and safety evaluation. In best overall response assessment, there were 7.4% CR (2/27), 66.7% PR (18/27) and 25.9% SD (7/27). ORR was 74.1% (95%CI: 53.7. ~ 88.9), and DCR was 100.0% (95%CI: 87.2~100.0). The median PFS of the 27 pts was not yet available. The safety profile indicated that the most common drug-related adverse events were myelosuppression, gastrointestinal reaction, fatigue, hypertension, constipation, hypokalemia and hepatotoxicity. The common grade 3-4 treatment-related adverse events were myelosuppression (18.5%), hypertension (7.4%). Conclusions: The current results indicated that paclitaxel and cisplatin combined with anlotinib as first line therapy for advanced ESCC exhibited encouraging efficacy and manageable adverse events. The conclusion should be validated in more pts consecutively. Clinical trial information: NCT04063683. [Table: see text]

Laser Responsive Cisplatin-Gold Nano-Assembly Synergizes the Effect of Cisplatin With Compliance.

Cisplatin therapy faces low bioavailability and clastogenic potential limitations. Early payload leakage of nanocarriers may impair adequate therapeutic efficacy. We propose encapsulation of cisplatin in such nanocarrier that can be externally stimulated for high payload release and enhanced toxicity at site of action. Cisplatin conjugated gold nanorods (Pt-AuNRs) have been synthesized and characterized through UV visible spectroscopy, dynamic light scattering and transmission electron microscopy. Physico-chemical characterization through X-ray photon spectrometry confirms the covalent linkage between linker and aquated cisplatin with AuNRs. Laser exposure (850nm, CW) enabled ~15-fold payload release from Pt-AuNRs nano-assembly, which is quite high (P<0.0001) compared to non-stimulated conditions. The median growth inhibitory concentration (GI50) after laser exposure of Pt-AuNRs was ~11- and 13-fold low compared to corresponding Pt-AuNRs without laser exposure and cisplatin respectively, in sarcoma cells. Synergistic therapeutic difference is more significant (P<0.01), at lower concentrations of Pt-AuNRs (0.5-10μg/mL). Pt-AuNRs photothermal therapy indicates a convincible association of over-production of reactive oxygen species (P<0.0001) and synergistic therapeutic efficacy. Clastogenic potential is found non-significant for Pt-AuNRs (10μg/mL). Cisplatin nanoconjugate shows biocompatibility against blood cells. In conclusion, laser-stimulated Pt-AuNRs appear a promising drug delivery with synergistic toxic potential against cancer while attenuating cisplatin toxicity.

Combination therapy of cisplatin with cilastatin enables an increased dose of cisplatin, enhancing its antitumor effect by suppression of nephrotoxicity

Cisplatin, one of the most active anticancer agents, is widely used in standard chemotherapy for various cancers. Cisplatin is more poorly tolerated than other chemotherapeutic drugs, and the main dose-limiting toxicity of cisplatin is its nephrotoxicity, which is dose-dependent. Although less toxic methods of cisplatin administration have been established, cisplatin-induced nephrotoxicity remains an unsolved problem. Megalin is an endocytic receptor expressed at the apical membrane of proximal tubules. We previously demonstrated that nephrotoxic drugs, including cisplatin, are reabsorbed through megalin and cause proximal tubular cell injury. We further found that cilastatin blocked the binding of cisplatin to megalin in vitro. In this study, we investigated whether cilastatin could reduce cisplatin-induced nephrotoxicity without influencing the antitumor effects of cisplatin. Nephrotoxicity was decreased or absent in mice treated with cisplatin and cilastatin, as determined by kidney injury molecule-1 staining and the blood urea nitrogen content. Combined with cilastatin, a twofold dose of cisplatin was used to successfully treat the mice, which enhanced the antitumor effects of cisplatin but reduced its nephrotoxicity. These findings suggest that we can increase the dose of cisplatin when combined with cilastatin and improve the outcome of cancer patients.

Functional Alterations of Multidrug Resistance-Associated Proteins 2 and 5, and Breast Cancer Resistance Protein upon Snail-Induced Epithelial-Mesenchymal Transition in HCC827 Cells.

Our previous report indicated that Snail-induced epithelial-mesenchymal transition (EMT) enhanced P-glycoprotein (P-gp) function and drug resistance to P-gp substrate anticancer drug in a human non-small cell lung cancer (NSCLC) cell line, HCC827. Our objective is to evaluate the changes in the mRNA and protein expression levels and the functions of multidrug resistance-associated protein (MRP) 2, MRP5 and breast cancer resistance protein (BCRP). Snail-expressing HCC827 cells showed increased mRNA levels of Snail and a mesenchymal marker vimentin, and decreased mRNA levels of an epithelial marker E-cadherin after transduction, indicating that Snail had induced EMT consistent with our previous reports. The mRNA level of MRP2 was significantly decreased, while that of MRP5 remained unchanged, in Snail-expressing cells. The expression levels of MRP2 and MRP5 proteins in whole-cell homogenate were unchanged in Snail-expressing cells, but MRP5 protein showed significantly increased membrane localization. Snail-transduction increased the efflux transport of 5-(and-6)-carboxy-2',7'-dichlorofluorescein (CDCF), a substrate of MRP2, 3 and 5. This increase was blocked by MK571, which inhibits MRP1, 2, and 5. Toxicity of cisplatin, a substrate of MRP2 and 5, was significantly decreased in Snail-expressing cells. BCRP mRNA and protein levels were both decreased in Snail-expressing cells, which showed an increase in the intracellular accumulation of 7-ethyl-10-hydroxycamptothecin (SN-38), a BCRP substrate, resulting in reduced viability. These results suggested that MRP5 function appears to be increased via an increase in membrane localization, whereas the BCRP function is decreased via a decrease in the expression level in HCC827 cells with Snail-induced EMT.

The natural compound n-butylidenephthalide kills high-grade serous ovarian cancer stem cells by activating intrinsic apoptosis signaling pathways.

High-grade serous ovarian cancer (HGSOC) constitutes 80% of ovarian cancer. Cancer stem cells (CSCs) are responsible for most of the tumor metastasis and chemoresistance. n-Butylidenephthalide (BP) is a potential anti-tumor agent for treating a variety of cancers. The aim of this study was to evaluate the effect of BP on CSCs of HGSOC. CSCs were isolated using the CSC marker (ALDH; aldehyde dehydrogenase) from KURAMOCHI and OVSAHO cells (HGSOC cell lines). The cell proliferation, IC50 (the half-maximal inhibitory concentration), cell migration and invasion, TUNEL (terminal deoxynucleotidyl transferase (TdT) dUTP nick end labeling) assay, western blot of ovarian CSC were evaluated. The animal xenograft studies were evaluated on an immunodeficient mouse model. The results showed the proliferation of ALDH+ cells was greater than that of ALDH- cells. The dosage of IC50 of BP was higher in ALDH+ cells than in mixed cancer cells (317.2 vs. 206.5 μg/ml) in KURAMOCHI cells, but not in OVSAHO cells (61.1 vs. 48.5 μg/ml). BP could inhibit the migration and invasion of both cancer stem cells. BP treatment could activate apoptosis signaling, as indicated by the TUNEL assay and the increased expression of cleaved caspase-3, -7, and -9 but not cleaved caspase-8. A low dose of BP (20 and 25 μg/mL) treatment could increase the toxicity of taxol and cisplatin. In the animal model, BP (200 mg/kg) treatment also decreased the KURAMOCHI and OVSAHO tumor growth rate and induced tumor apoptosis. In conclusion, BP could kill ALDH+ CSCs of HGSOC in vitro and in vivo by inducing apoptosis. BP may provide a new therapeutic approach for HGSOC.

Impact of aliphatic acyl and aromatic thioamide substituents on the anticancer activity of Ru(II)-p-cymene complexes with acylthiourea ligands-in vitro and in vivo studies.

Six different acylthiourea ligands (L1-L6) and their corresponding Ru(II)-p-cymene complexes (P1-P6) were designed to explore the structure-activity relationship of the complexes upon aliphatic chain and aromatic conjugation on the C- and N-terminals, respectively. The compounds were synthesized and adequately characterized using various analytical and spectroscopic techniques. The structures of P2-P6, solved using single crystal X-ray diffraction (XRD), confirmed the neutral monodentate coordination of the S atoms of the acylthiourea ligands to Ru(II) ions. In silico studies showed an increase of lipophilicity for the ligands with an increase in alkyl chain length or aromatic conjugation at the C- or N-terminal, respectively. Subsequently, mitogen-activated protein kinases (MAPK) were predicted as one of the primary targets for the complexes, which showed good binding affinity towards extracellular signal-regulated kinases (ERK1, ERK2 and ERK5), c-Jun N-terminal kinase (JNK) and p38 of the MAPK pathway. Henceforth, the complexes were tested for their anticancer activity in lung carcinoma (A549) and cisplatin-resistant lung carcinoma (cisA549R) cells and human umbilical vein epithelial normal cells (HUVEC). Interestingly, an increase in chain length or aromatic conjugation led to an increase in the activity of the complexes, with P5 (7.73 and 13.04 μM) and P6 (6.52 and 14.45 μM) showing the highest activity in A549 and cisA549R cells, which is better than the positive control, cisplatin (8.72 and 44.28 μM). Remarkably, we report the highest activity yet observed for complexes of the type [(η6-p-cymene)RuIICl2(S-acylthiourea)] in the tested cell lines. Aqueous solution studies showed that complexes P5 and P6 are rapidly hydrolyzed to produce solely aquated species that remained stable for 24 h. Staining assays and flow cytometric analyses of P5 and P6 in A549 cells revealed that the complexes induced apoptosis and arrested the cell cycle predominantly in the S phase. In vivo studies demonstrated the higher toxicity of cisplatin and a comparatively higher survival rate of mice injected with the most active complex P6. Histological analyses revealed that treatment with P6 at high doses of up to 8 mg kg-1 did not cause any palpable damage to the tested organs.