Nephrotoxicity of a novel antineoplastic platinum complex, nedaplatin: a comparative study with cisplatin in rats

Research Progress of Metal Anticancer Drugs

Cancer treatments, including traditional chemotherapy, have failed to cure human malignancies. The main reasons for the failure of these treatments are the inevitable drug resistance and serious side effects. In clinical treatment, only 5 percent of the 50 percent of cancer patients who are able to receive conventional chemotherapy survive. Because of these factors, being able to develop a drug and treatment that can target only cancer cells without affecting normal cells remains a big challenge. Since the special properties of cisplatin in the treatment of malignant tumors were accidentally discovered in the last century, metal anticancer drugs have become a research hotspot. Metal anticancer drugs have unique pharmaceutical properties, such as ruthenium metal drugs with their high selectivity, low toxicity, easy absorption by tumor tissue, excretion, and so on. In recent years, efficient and low-toxicity metal antitumor complexes have been synthesized. In this paper, the scientific literature on platinum (Pt), ruthenium (Ru), iridium (Ir), gold (Au), and other anticancer complexes was reviewed by referring to a large amount of relevant literature at home and abroad.

PEGylated Chitosan Nanoparticles Loaded with Betaine and Nedaplatin Hamper Breast Cancer: In Vitro and In Vivo Studies

The current study investigates the anticancer effects of PEGylated chitosan nanoparticles (CS NPs) coloaded with betaine (BT) and nedaplatin (ND) on breast adenocarcinoma (MCF-7) cells and breast cancer-bearing rats. Hereof, the ionotropic gelation approach was implemented for the synthesis of PEG-uncoated and PEG-coated CS NPs encompassing either BT, ND, or both (BT-ND). The sizes of the developed BT/CS NPs, ND/CS NPs, and BT-ND/CS NPs were 176.84 ± 7.45, 204.1 ± 13.6, and 201.1 ± 23.35 nm, respectively. Meanwhile, the sizes of the synthesized BT/PEG-CS NPs, ND/PEG-CS NPs, and BT-ND/PEG-CS NPs were 165.1 ± 32.40, 148.2 ± 20.98, and 143.7 ± 7.72 nm, respectively. The surface charges of the fabricated nanoparticles were considerably high. All of the synthesized nanoparticles displayed a spherical form and significant entrapment efficiency. Release experiments demonstrated that the PEGylated and non-PEGylated CS NPs could discharge their contents into the tumor cells' microenvironments (pH 5.5). In addition, the NPs demonstrated an outstanding ability to reduce the viability of the MCF-7 cell line. In addition, BT-ND/PEG-CS NPs were found to be the strongest among all NP preparations, where they caused around 90% decrease in the size of mammary gland tumors in rats compared to vehicle-treated animals.

Renal Crest Proliferative Lesions in Cats with Chronic Kidney Disease

In a histopathological study of the renal crest (RC) of kidneys of cats with chronic kidney disease (CKD), 58/90 (64%) had epithelial proliferation. Of these, 33 cats had hyperplasia of the collecting duct (CD) epithelium (CDH) alone, eight had hyperplasia of the urothelium covering the RC (RCUH), of which one had concurrent abaxial renal pelvic urothelial hyperplasia (UH), and eight had both CDH and RCUH. CDH or RCUH were present in five cats with marked dysplasia of the CD epithelium (CDD) and four cats with invasive carcinomas, which also had epithelial dysplasia. All nine cats with marked dysplasia or neoplasia of the RC also had substantially altered RC contours due to focal haemorrhage, papillary necrosis or fibrosis. Three of the carcinomas had a strong desmoplastic response. In control cats, both urothelial (RC and renal pelvis) and tubular (CD and distal tubular) cells were immunopositive for cytokeratin (CK; AE1/AE3), tubular epithelial cells were positive for vimentin (Vim) and aquaporin 2 (Aq2), while urothelial cells were positive for p63. PAX8 immunolabelling was difficult to validate. CD and UH labelling was similar to control tissue. While urothelial dysplasia had the same immunolabelling pattern as UH and control tissue, CDD was generally immunonegative for Aq2. As immunolabelling of the four carcinomas did not distinguish between tubular and urothelial origin, with three positive for both Vim and p63, all were broadly designated as RC carcinomas. Overall, proliferative epithelial lesions are common in cats with CKD and form a continuum from simple hyperplasia to neoplasia of the urothelium or CD of the RC.

Anticancer effects of dihydromyricetin on the proliferation, migration, apoptosis and in vivo tumorigenicity of human hepatocellular carcinoma Hep3B cells

Background

Hepatocellular carcinoma (HCC) represents a serious public health problem worldwide and has high morbidity and mortality. Dihydromyricetin (DHM) exhibits anticancer effect on a variety of malignancies, but its anticancer function of DHM in HCC has been unclear. The aim of this study was designed to investigate the anticancer effect of DHM on cell apoptosis, proliferation, migration and invasion of hepatoma carcinoma cells.

Methods

Cultured Hep3B cells were treated with different DHM concentrations, followed by cell apoptosis, proliferation, migration and invasion were examined by CCK-8, colony formation assay, wound healing, Transwell and flow cytometry, respectively. The mRNA and protein expression of BCL-2, Cleaved-caspase 3, Cleaved-caspase 9, BAK, BAX and BAD were validated by western blot.

Results

DHM markedly suppressed proliferation, migration, invasion and facilitated apoptosis in Hep3B cells. Mechanistically, DHM significantly downregulated the Bcl-2 expression, and upregulated the mRNA and protein levels of Cleaved-Caspase 3, Cleaved- Caspase 9, Bak, Bax and Bad. Furthermore, in the nude mice tumorigenic model, DHM treatment greatly decreased the weight of the HCC cancers compared to the weights in control and NDP group.

Conclusions

DHM could suppress cell proliferation, migration, invasion, and facilitated apoptosis in Hep3B cells. These findings could provide novel insights to develop potential therapeutic strategy for the clinical treatment of HCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03356-5.

The updated outcomes of bladder-preserving trimodal therapy using a real-time tumor-tracking radiotherapy system for patients with muscle-invasive bladder cancer

Objective

Bladder-preserving trimodal therapy is recognized as a promising alternative treatment for muscle-invasive bladder cancer. We report the updated outcomes of muscle-invasive bladder cancer patients that were treated using our treatment protocol, which involves radiotherapy delivered with a real-time tumor-tracking radiotherapy system.

Methods

Thirty-eight patients who were diagnosed with T2-T4N0M0 bladder cancer between 1998 and 2016 and had clinically inoperable disease or refused to undergo surgery were enrolled. The treatment protocol included maximal transurethral resection followed by whole-bladder radiotherapy (40 Gy). Concurrent nedaplatin-based chemotherapy was administered to patients with adequate renal function. At the time of the first evaluation (via transurethral resection of the tumor bed), fiducial markers were endoscopically inserted into the bladder wall around the tumor. A boost of 25 Gy was administered using the real-time tumor-tracking radiotherapy system. The second evaluation (via transurethral resection of the tumor bed) was performed 6 months after the start of treatment. The Kaplan–Meier method and Cox hazards analysis were used to analyze overall survival and cancer-specific survival.

Results

The median duration of the follow-up period was 28 months (range: 3–161 months). The 5- and 10-year overall survival rates were 54.9 and 41.2%, respectively. Twenty-five (65.8%) and twenty (74.1%) patients had achieved complete responses to chemoradiation at the first and second evaluations, respectively. In univariate and multivariate analyses, performance status was found to be significantly associated with overall survival [P = 0.03, hazard ratio: 3.48, 95% confidence interval: 1.15–10.6] and cancer-specific survival [P = 0.02, hazard ratio: 4.57, 95% confidence interval: 1.32–16.9], and sex was shown to be significantly associated with cancer-specific survival [P = 0.03, hazard ratio: 3.07, 95% confidence interval: 1.09–8.30].

Conclusions

Our bladder-preserving trimodal therapy protocol, which involves the use of a real-time tumor-tracking radiotherapy system, produced an acceptable overall survival rate. This therapy is a reasonable alternative for patients that are medically unfit for or do not want to undergo cystectomy.

Silk Reservoirs for Local Delivery of Cisplatin for Neuroblastoma Treatment: In Vitro and In Vivo Evaluations

Neuroblastoma is the most common extracranial childhood tumor, and current treatment requires surgical resection and multidrug chemotherapy. Local, perioperative delivery of chemotherapeutics is a promising treatment method for solid tumors that require surgical removal. In this study, we have aimed to develop a controlled-release implant system to deliver cisplatin in tumor or tumor resection area. Silk fibroin, a biodegradable, nonimmunogenic biopolymer was used to encapsulate different doses of cisplatin in a reservoir system. The physical integrity of the reservoirs was characterized by evaluating the crystalline structure of silk secondary structure using FTIR spectroscopy. The in vitro release of cisplatin was evaluated in phosphate-buffered saline at 37°C, and the reservoirs were able to release the drug up to 30 days. The cytotoxicity of cisplatin and cisplatin reservoirs were tested on KELLY cells. Cytotoxicity data showed 3.2 μg/mL cisplatin was required to kill 50% of the cell population, and the released cisplatin from the silk reservoirs showed significant cytotoxicity up to 21 days. Intratumoral implantation of silk reservoirs into an orthotopic neuroblastoma mouse model decreased tumor growth significantly when compared with control subjects. These results suggest that silk reservoirs are promising carriers for cisplatin delivery to the tumor site.

Analysis of adverse events of renal impairment related to platinum-based compounds using the Japanese Adverse Drug Event Report database

Objectives:

Platinum compounds cause several adverse events, such as nephrotoxicity, gastrointestinal toxicity, myelosuppression, ototoxicity, and neurotoxicity. We evaluated the incidence of renal impairment as adverse events are related to the administration of platinum compounds using the Japanese Adverse Drug Event Report database.

Methods:

We analyzed adverse events associated with the use of platinum compounds reported from April 2004 to November 2016. The reporting odds ratio at 95% confidence interval was used to detect the signal for each renal impairment incidence. We evaluated the time-to-onset profile of renal impairment and assessed the hazard type using Weibull shape parameter and used the applied association rule mining technique to discover undetected relationships such as possible risk factor.

Results:

In total, 430,587 reports in the Japanese Adverse Drug Event Report database were analyzed. The reporting odds ratios (95% confidence interval) for renal impairment resulting from the use of cisplatin, oxaliplatin, carboplatin, and nedaplatin were 2.7 (2.5–3.0), 0.6 (0.5–0.7), 0.8 (0.7–1.0), and 1.3 (0.8–2.1), respectively. The lower limit of the reporting odds ratio (95% confidence interval) for cisplatin was >1. The median (lower–upper quartile) onset time of renal impairment following the use of platinum-based compounds was 6.0–8.0 days. The Weibull shape parameter β and 95% confidence interval upper limit of oxaliplatin were <1. In the association rule mining, the score of lift for patients who were treated with cisplatin and co-administered furosemide, loxoprofen, or pemetrexed was high. Similarly, the scores for patients with hypertension or diabetes mellitus were high.

Conclusion:

Our findings suggest a potential risk of renal impairment during cisplatin use in real-world setting. The present findings demonstrate that the incidence of renal impairment following cisplatin use should be closely monitored when patients are hypertensive or diabetic, or when they are co-administered furosemide, loxoprofen, or pemetrexed. In addition, healthcare professionals should closely assess a patient’s background prior to treatment.

Comparative analysis of gene expression between renal cortex and papilla in nedaplatin-induced nephrotoxicity in rats

To elucidate the mechanism of nephrotoxicity caused by anti-neoplastic platinum complex, nedaplatin (NDP), treatment with a particular focus on the renal papillary toxicity, we analysed the gene expression profiles of two renal regions, the cortex (RC) and the papilla (RP) in rat kidneys. Male Wistar rats received a single administration of 10 mg/kg intravenous NDP or vehicle alone (5% xylitol solution) and were sacrificed six days later. The kidneys were dissected into the RC and RP and used for histopathological and microarray analyses. Histopathologically, NDP caused characteristic renal lesions, such as necrosis, single cell necrosis (with TUNEL TdT-mediated dUTP-biotin nick end labelling-positive) and regeneration/hyperplasia of the epithelial cells in both renal regions. Global gene expression analysis revealed that several genes involved in various functional categories were commonly deregulated in both renal regions, such as apoptosis, cell cycle regulation, DNA metabolism, cell migration/adhesion and cytoskeleton organization or genes induced as a perturbation of oxidative status and calcium homeostasis. Comparative analysis of gene expression between RC and RP revealed that genes encoding several subtypes of cytokeratins were identified as being specifically overexpressed in RP by the NDP treatment. Differential expression patterns of these selected genes observed by microarray analysis were further confirmed by quantitative real time RT-PCR and immunohistochemistry, which demonstrated increased expression of cytokeratins (CKs) 14 and 19 at the epithelium covering RP and/or collecting duct epithelium. Overall, the results contribute to understanding the renal molecular events of NDP-induced nephrotoxicity including novel potential biomarker genes encoding CKs 14 and 19 that may serve as indicators of renal papillary toxicity. Human & Experimental Toxicology (2007) 26, 767—780

Nedaplatin salvage chemotherapy for cervical cancer

PURPOSE

This systematic analysis was conducted to evaluate the efficacy and safety of nedaplatin based salvage chemotherapy for treatment of patients with advanced cervical cancer.

METHODS

Clinical studies evaluating the efficacy and safety of nedaplatin based regimens on response and safety for patients with cervical cancer were identified using a predefined search strategy. Pooled response rates (RRs) were calculated.

RESULTS

For nedaplatin based regimens, 5 clinical studies including 264 patients with advanced cervical cancer were considered eligible for inclusion. The analysis showed that, in all patients, pooled RR was 74.6% (197/264). Major adverse effects were leukopenia, thrombocytopenia and nausea/vomiting. No treatment related death occurred with nedaplatin based treatment.

CONCLUSION

This systematic analysis suggests that nedaplatin based regimens are associated with good activity with acceptable tolerability in treating patients with advanced cervical cancer.

Efficacy and safety of nedaplatin-based concurrent chemoradiotherapy for FIGO Stage IB2-IVA cervical cancer and its clinical prognostic factors

Cisplatin-based concurrent chemoradiotherapy (CCRT) is a standard treatment for cervical cancer, but nedaplatin-based CCRT is not routinely administered. We evaluated the efficacy and safety of nedaplatin-based CCRT (35 mg/m(2) weekly) and analyzed prognostic factors for survival among 52 patients with International Federation of Gynecology and Obstetrics (FIGO) Stage IB2-IVA cervical cancer treated from 1999 to 2009. Patients were treated with a combination of external beam radiotherapy of 40-56 Gy (in 20-28 fractions) and 13.6-28.8 Gy (in 2-4 fractions) of high-dose-rate (HDR) intracavitary brachytherapy or 18 Gy (in 3 fractions) of HDR interstitial brachytherapy. Overall survival (OS), progression-free survival (PFS), and local control (LC) were estimated using the Kaplan-Meier method. The Cox proportional hazard model was used for multivariate analysis. Acute and late toxicities were evaluated using the Common Terminology Criteria for Adverse Events version 4.0. The median follow-up period was 52 months. The median patient age was 63 years. The 5-year OS, PFS and LC rates were 78%, 57% and 73%, respectively. Multivariate analysis showed that histologic type, maximum tumor diameter, and pretreatment hemoglobin level were independent risk factors for PFS. Regarding adverse effects, 24 patients (46%) had acute Grade 3-4 leukopenia and 5 (10%) had late Grade 3 gastrointestinal toxicities. No patient experienced renal toxicity. Nedaplatin-based CCRT for FIGO Stage IB2-IVA cervical cancer was efficacious and safe, with no renal toxicity. Histologic type, maximum tumor diameter, and pretreatment hemoglobin level were statistically significant prognostic factors for PFS.

A phase II study of concurrent chemo-radiotherapy with weekly nedaplatin in advanced squamous cell carcinoma of the uterine cervix

Background

To evaluate the efficacy and safety of concurrent chemo-radiotherapy with weekly nedaplatin for the treatment of advanced squamous cell carcinoma of the uterine cervix.

Methods

Patients with stage Ib2 to IIIb squamous cell carcinoma of the uterine cervix were treated with concurrent radiotherapy and chemotherapy. The radiotherapy regimen included external beam radiation therapy (45–50.4Gy/25-28 fractions with central shielding after 30.6Gy) and high-dose-rate brachytherapy irradiation (35-49Gy/5-7 fractions to point A). The chemotherapy regimen was weekly intravenous infusion of nedaplatin (30 mg/m², once weekly, 180 mg/m² for 6 weeks).

Results

Thirty patients were enrolled in this study from April 2010 to October 2010. The median age was 50.5 years (34–62). Three patients were at the clinical stage IIa2, twenty at stage IIb and seven at stage IIIb. Acute hematological toxicities included grade 3 leukopenia (8), neutropenia (5), anemia (2), grade 4 anemia (1), and grade 2 thrombocytopenia (6). Acute non-hematological toxicities included grade 2 liver disorders (1), diarrhea (2), nausea (2), and renal toxicity (1). There were not grade 3 or worse toxicities. 24 patients completed the treatment regimen and were evaluated for efficacy. 23 patients (95.8%) had CR (complete response) and 1 (4.2%) had PR (partial response) (100% response rate). The median follow-up duration was 36 months (23–39), during which three patients relapsed after the treatment. The 3-year PFS and OS rates were 87.5% and 91.7%, respectively.

Conclusions

This phase II study suggested that concurrent chemo-radiotherapy with weekly nedaplatin was effective and safe for the treatment of advanced squamous cell carcinoma of the uterine cervix.

Prospective phase II study of image-guided local boost using a real-time tumor-tracking radiotherapy (RTRT) system for locally advanced bladder cancer

OBJECTIVE

The real-time tumor-tracking radiotherapy system with fiducial markers has the advantage that it can be used to verify the localization of the markers during radiation delivery in real-time. We conducted a prospective Phase II study of image-guided local-boost radiotherapy for locally advanced bladder cancer using a real-time tumor-tracking radiotherapy system for positioning, and here we report the results regarding the safety and efficacy of the technique.

METHODS

Twenty patients with a T2-T4N0M0 urothelial carcinoma of the bladder who were clinically inoperable or refused surgery were enrolled. Transurethral tumor resection and 40 Gy irradiation to the whole bladder was followed by the transurethral endoscopic implantation of gold markers in the bladder wall around the primary tumor. A boost of 25 Gy in 10 fractions was made to the primary tumor while maintaining the displacement from the planned position at less than ±2 mm during radiation delivery using a real-time tumor-tracking radiotherapy system. The toxicity, local control and survival were evaluated.

RESULTS

Among the 20 patients, 14 were treated with concurrent chemoradiotherapy. The median follow-up period was 55.5 months. Urethral and bowel late toxicity (Grade 3) were each observed in one patient. The local-control rate, overall survival and cause-specific survival with the native bladder after 5 years were 64, 61 and 65%.

CONCLUSIONS

Image-guided local-boost radiotherapy using a real-time tumor-tracking radiotherapy system can be safely accomplished, and the clinical outcome is encouraging. A larger prospective multi-institutional study is warranted for more precise evaluations of the technological efficacy and patients' quality of life.

Intervention effects of nedaplatin and cisplatin on proliferation and apoptosis of human tumour cells in vitro

OBJECTIVE

To study synergistic effects of nedaplatin and cisplatin on three human carcinoma cell lines (esophageal carcinoma cell line Eca-109, ovarian carcinoma Skov-3 and cervical carcinoma Hela).

METHODS

Inhibition effects were evaluated by MTT assay and cell apoptosis was detected by flow cytometry. In addition, changes of Ki-67, Bax and Bcl-2 at mRNA and protein levels were quantified by RT-PCR and Western blotting.

RESULTS

Growth inhibition in each cell lines was dose-dependent after exposure to nedaplatin or cisplatin alone. The interaction of the two drugs was synergistic at higher concentrations according to the median-effect principle. The inhibition rates with nedaplatin, cisplatin and combined treatment were 41.9±4.1%, 47.4±2.9%, 52.5±0.9%(Eca-109), 39.0±1.26%, 45.0±1.45% , 56.2±1.44% (Skov-3) and 44.8±2.11%, 46.9±0.99%, 56.6±1.83% (Hela) respectively, with increase in apoptosis. Compared with the nedaplatin or cisplatin alone treatment group, the combinative treatment group's Ki-67 and bcl-2 mRNA (protein) expression was decreased while that of Bax mRNA (protein) was increased.

CONCLUSION

Compared to the effects of nedaplatin or cisplatin alone at high concentrations, combination of nedaplatin and cisplatin at low concentrations proved to be much more effective for inhibition of proliferation and the induction of apoptosis in the Eca-109, Skov-3 and Hela cell lines.

Review: ototoxic characteristics of platinum antitumor drugs

Cisplatin, carboplatin, nedaplatin, and oxaliplatin are widely used in contemporary oncology; however, their ototoxic and neurotoxic side effects are quite different as discussed in this review. Cisplatin is considered the most ototoxic, but despite its reputation, the magnitude of hair cell loss that occurs with a single, large drug bolus is limited and confined to the base of the cochlea. For all of these platinum compounds, a major factor limiting damage is drug uptake from stria vascularis into the cochlear fluids. Disrupting the blood-labyrinth barrier with diuretics or noise exposure enhances drug uptake and significantly increases the amount of damage. Combined treatment with ethacrynic acid (a loop diuretic) and cisplatin results in rapid apoptotic hair cell death characterized by upregulation of initiator caspase-8 and membrane death receptor, TRADD, followed by downstream executioners, caspase-3 and caspase-6. Unlike cisplatin, nedaplatin and oxaliplatin are highly neurotoxic when applied to cochlear cultures preferentially damaging auditory nerve fibers at low concentrations and hair cells at high concentrations. Carboplatin, considered far less ototoxic than cisplatin, is paradoxically highly toxic to chinchilla inner hair cells and type I spiral ganglion neurons; however, at high doses it also damages outer hair cells. Hair cell death from cisplatin and carboplatin is characterized in its early stages by upregulation of p53; blocking p53 expression with pifithrin-α prevents hair cell death. Major differences in the toxicity of these four platinum compounds may arise from several different metal transporters that selectively regulate the influx, efflux, and sequestration of these drugs.

Effect of erythropoietin therapy on the progression of cisplatin induced renal injury in rats

Cisplatin is one of the most important chemotherapeutic agents useful in the treatment of a variety of solid tumors; however, it has several side effects such as nephrotoxicity. In the present study, the effect of rhEPO on acute kidney injury induced by i.p. injection of rats with 9.0 mg/kg cisplatin was studied. It was observed that EPO treated group showed a significantly lower rate in the extent and severity of the histological signs of kidney injury than untreated one. This is attributed to (i) a decrease in the elevated oxidative and nitrosative stress markers, (ii) reduction of the expression of VEGF, HO-1 and iNOS as well as (iii) improvement of Bcl2 immunoreaction in most tubular cells. Thus, EPO may be one of the futures therapeutic possibilities to overcome the side effects of anti-cancer drugs induced acute renal injury through various mechanisms including down regulation of vascular endothelial growth factor (VEGF), hemeoxygenase-1 (HO-1) and inducible nitric oxide synthase (iNOS) expressions in addition to stimulation of tubular cell regeneration.

Celecoxib, a selective cyclooxygenase-2 inhibitor, attenuates renal injury in a rat model of Cisplatin-induced nephrotoxicity

BACKGROUND

Cisplatin is an effective chemotherapeutic agent successfully used in the treatment of a wide range of tumors. Nevertheless, nephrotoxicity has restricted its clinical use. Recent studies have strongly suggested that inflammatory mechanisms may play an important role in the pathogenesis of cisplatin nephrotoxicity. Celecoxib, a selective cyclooxygenase-2 inhibitor used as anti-inflammatory, may therefore have a protective effect on cisplatin-induced renal injury.

METHODS

In the present study, rats were injected intraperitoneally with a single dose of cisplatin (7 mg/kg) and/or celecoxib (30 mg/kg) for 5 days.

RESULTS

Nephrotoxicity manifested biochemically by elevations in serum creatinine, blood urea nitrogen, and proteinuria, and an increase in kidney weight as a percentage of total body weight. In addition, a marked decrease in serum albumin was observed. Lipid peroxidation in the kidney was monitored by measuring the malondialdehyde level and glutathione content, which were increased and depleted, respectively. Administration of celecoxib with cisplatin attenuated cisplatin-induced changes in kidney function parameters and oxidative stress markers. Histopathological examination of the kidney confirmed these results.

CONCLUSION

In conclusion, this study indicates that celecoxib may be a promising drug for clinical use as a nephroprotectant against cisplatin-induced nephrotoxicity.

Comparative nephrotoxicity of Cisplatin and nedaplatin: mechanisms and histopathological characteristics

The antineoplastic platinum complexes cisplatin and its analogues are widely used in the chemotherapy of a variety of human malignancies, and are especially active against several types of cancers. Nedaplatin is a second-generation platinum complex with reduced nephrotoxicity. However, their use commonly causes nephrotoxicity due to a lack of tumor tissue selectivity. Several recent studies have provided significant insights into the molecular and histopathological events associated with nedaplatin nephrotoxicity. In this review, we summarize findings concerning the renal histopathology and molecular pathogenesis induced by antineoplastic platinum complexes, with a particular focus on the comparative nephrotoxicity of cisplatin and nedaplatin in rats.

Emergence of biomarkers in nephropharmacology

Blood-urea nitrogen, serum creatinine and urine output have long been used as markers of kidney function despite their known limitations. In the past few years, a number of novel biomarkers have been identified in the urine and blood that can detect kidney injury early. Although, to date, none of these biomarkers are in clinical use, many have been validated as reliable and sensitive, allowing detection of kidney injury before serum creatinine levels rise and urine output drops. These markers have been evaluated in great detail in animal models and to a lesser extent in humans in postcardiopulmonary bypass and sepsis. There is relatively scarse data on the use of these biomarkers in the detection of kidney injury associated with the use of pharmacologic agents. The purpose of this article is to summarize these data and highlight the potential utility of these biomarkers in nephropharmacology.

Postoperative whole pelvic radiotherapy plus concurrent chemotherapy versus extended-field irradiation for early-stage cervical cancer patients with multiple pelvic lymph node metastases

OBJECTIVES

The aim of this study was to compare the efficacy of postoperative pelvic radiotherapy plus concurrent chemotherapy with that of extended-field irradiation (EFRT) in patients with FIGO Stage IA2-IIb cervical cancer with multiple pelvic lymph node metastases.

METHODS

We retrospectively reviewed the medical records of patients with FIGO Stage IA2-IIb cervical cancer who had undergone radical surgery between April 1997 and March 2008. Of these, 55 patients who demonstrated multiple pelvic lymph node metastases were treated postoperatively with pelvic radiotherapy plus concurrent chemotherapy (n=29) or EFRT (n=26). Thirty-six patients with single pelvic node metastasis were also treated postoperatively with pelvic radiotherapy plus concurrent chemotherapy. The recurrence rate, progression free survival (PFS), and overall survival (OS) were compared between the treatment groups.

RESULTS

Pelvic radiotherapy plus concurrent chemotherapy was significantly superior to EFRT with regard to recurrence rate (37.9% vs 69.2%, p=0.0306), PFS (log-rank, p=0.0236), and OS (log-rank, p=0.0279). When the patients were treated with pelvic radiotherapy plus concurrent chemotherapy, there was no significant difference in PFS or OS between the patients with multiple lymph node metastases and those with single node metastases. With regards to grade 3-4 acute or late toxicities, no statistically significant difference was observed between the two treatment groups.

CONCLUSIONS

Postoperative pelvic radiotherapy plus concurrent chemotherapy is superior to EFRT for treating patients with FIGO Stage IA2-IIb cervical cancer displaying multiple pelvic lymph node metastases.

Nedaplatin: a radiosensitizing agent for patients with cervical cancer

Despite the recent advances in the management of cervical cancer using cisplatin-based concurrent chemoradiotherapy, substantial treatment failure still occurs, especially in advanced-stage patients and early-stage cervical cancer patients with high-risk prognostic factors. Therefore, efforts to further improve the survival and quality of life of these patients are necessary. Nedaplatin (cis-diammine-glycoplatinum), a derivative of cisplatin, was developed with the aim of producing a treatment with a similar effectiveness to cisplatin but decreased renal and gastrointestinal toxicities. Based on the promising results of preclinical studies, the clinical efficacy of nedaplatin as a radiosensitizing agent was evaluated in patients with cervical cancer. Retrospective analysis of nedaplatin-based concurrent chemoradiotherapy (CCRT) against cervical cancer suggested that nedaplatin-based CCRT can be considered as an alternative to cisplatin-based CCRT in both early-stage and advanced-stage cervical cancer patients. However, due to the lack of a randomized controlled study, nedaplatin-based CCRT has not been convincingly proven to be clinically effective in patients with cervical cancer. Further investigations in randomized controlled trials are therefore needed.

Use of a toxicity factor to explain differences in nephrotoxicity and myelosuppression among the platinum antitumour derivatives cisplatin, carboplatin and nedaplatin in rats

The platinum antitumour drugs cisplatin, carboplatin and nedaplatin differ in their toxicity. The relationships between the pharmacokinetics of these drugs and developed parameters for predicting their nephrotoxicity and myelosuppression were investigated. The drugs were administered to male Wistar rats by intravenous bolus or infusion, and linearity of pharmacokinetics, total clearance and the apparent ratio of tissue concentrations of unchanged drug to plasma concentration (Kpapp) at steady state were determined. Apparent hydrolysis rates of each drug were determined in-vitro. Nephrotoxicity and myelosuppression were estimated by blood urea nitrogen (BUN) and platelet count, respectively. Tissue exposure to platinum was estimated as the product of the area under the plasma concentration-time curve for unchanged drug (AUCp), Kpapp and the apparent hydrolysis rate constant (khydrolysis), and toxicity factor was defined as the product of Kpapp × khydrolysis as an intrinsic drug parameter. The relationship between AUCp × toxicity factor and BUN fitted well to an Emax model. In bone marrow, this function was also correlated with platelet count. In summary, the product of AUCp × toxicity factor is a factor determining the pharmacokinetics of platinum drug-induced nephrotoxicity and myelosuppression in rats, and this toxicity factor may be a useful parameter for predicting the degree of toxicity of platinum antitumour compounds.

New-generation platinum agents for solid tumors

Cisplatin was one of the first chemotherapeutic agents to exhibit broad efficacy in solid tumors and it remains among the most widely used agents in the treatment of cancer. Its introduction inspired great efforts to design similarly effective platinum agents that overcome the three main limitations of cisplatin: toxicity, tumor resistance and poor oral bioavailability. However, 40 years after the initial discovery of cisplatin, only two platinum agents have garnered US FDA approval: carboplatin and oxaliplatin. Although hundreds of promising agents were tested in clinical trials during the 1990s, only oxaliplatin made it past clinical development. For a brief period, the economic cost of these unsuccessful efforts retarded further efforts to develop new agents. However, two exciting platinum agents have been brought to Phase III trials: satraplatin in hormone-refractory prostate cancer and picoplatin in small-cell lung cancer. If successful, they may inspire a new effort to bring better-designed platinum agents to market. This article reviews the clinical development of platinum agents to date and speculates on the role of platinum agents in the near future.

Preventive effect of aminoguanidine compared to vitamin E and C on cisplatin-induced nephrotoxicity in rats

In this study, the antioxidant effect of aminoguanidine on nephrotoxicity of a single dose of cisplatin is investigated and compared with the effects of well-known antioxidants vitamin C and E combination. Tubular damage and perivascular inflammation were observed in kidney samples of the cisplatin-administered groups. Aminoguanidine and vitamin C-E combination are found to be capable of preventing these effects of cisplatin. Liver tissues of all groups were intact. Cisplatin-induced oxidative stress was evidenced by significant decrease in glutathione and significant increase in malondialdehyde levels in kidney samples. Antioxidants with cisplatin decreased malondialdehyde levels. Antioxidants with cisplatin prevented the decrease in liver glutathione levels. The nephrotoxicity was confirmed biochemically by significant elevation of serum urea and creatinine levels. Both vitamin C-E combination and aminoguanidine prevented the increase in serum urea levels according to the cisplatin group.

Time course of the change and amelioration of nedaplatin-induced nephrotoxicity in rats

Nedaplatin (NDP) is a second-generation antineoplastic platinum complex, with reduced nephrotoxicity. Two experiments were conducted to characterize the time course of changes of its nephrotoxicity and to further evaluate whether hydration is useful for amelioration of nephrotoxicity. In the first experiment, 8-week-old male rats treated with 6 or 9 mg kg(-1) NDP at a single intravenous dose were killed 2, 4, 7 and 14 days after dosing. In the second experiment, nonhydrated (Nhyd) or hydrated (Hyd) rats, treated with a single intravenous dose of 20 mg kg(-1) NDP, were killed 7 days after dosing. Besides renal function and histopathological examinations, the urinary excretion of platinum was measured. Histopathologically, NDP-induced nephrotoxicity was initially characterized by single cell and/or focal necrosis in the epithelium of distal tubules and collecting ducts as well as proximal tubules. In the later stage, subsequent cystic dilatation and regeneration occurred in these affected tubules, but incomplete tissue repair was still observed in the kidney 14 days after dosing. However, NDP-induced nephrotoxicity was dramatically reduced by hydration, while it had no clear effects on myelotoxicity. Measurement of urinary platinum excretion revealed that the total amount of platinum excretion was significantly higher in Hyd-NDP rats than that in Nhyd-NDP rats. In terms of urinary concentration, Hyd-NDP rats showed a lower concentration compared with that in Nhyd-NDP rats. The current results suggest that NDP has the potential risk to cause nephrotoxicity at a human therapeutic dose without hydration and that pre- and post-hydration at dosing can ameliorate this nephrotoxicity.

Comparative nephrotoxicity of cisplatin and new octahedral Pt(IV) complexes

PURPOSE

Previously, we have reported that the newly synthesized octahedral Pt(IV) compound, trans,cis-Pt(acetato)(2)Cl(2)(1,4-butanediamine), K101 and trans,cis-Pt(trifluoroacetato)(2)Cl(2)(1,4-butanediamine), K102 showed potent antitumor activities in vitro and in vivo. In order to compare the nephrotoxicity of the newly synthesized Pt(IV) complexes, K102 and K102 with cisplatin, we performed various tests.

MATERIALS AND METHODS

We performed a single dose acute toxicity test for LD(50) values determination, biochemical assays in blood serum, acid phosphatase enzyme histochemistry and transmission electron microscopic studies in renal proximal tubular cells in mice in vivo. The route of drugs administration is intraperitoneal injection.

RESULTS

In biochemical assays, the serum levels of BUN were significantly elevated at 6 h (p < 0.001), 1 day (p < 0.05) and 3 days (p < 0.001) after injection in cisplatin treated mice (6 mg/kg, single dose, i.p.). On the other hand, the serum levels of BUN were slightly elevated at 6 h (p < 0.01) only in K101 treated mice (8.2 mg/kg, single dose, i.p.), and were significantly raised at 6 h, 1 and 3 days (p < 0.05) after injection in K102 treated mice (6.2 mg/kg, single dose, i.p.). The higher serum BUN level in K102 treated mice is considered that K102 possesses more lipophilic fluoro group than acetyl group in K101. The values of creatinine and uric acid were similar in all groups. The ultrastructural morphological changes of K101- or K102-administrated mice were less remarkable than cisplatin-administrated mice. In acid phosphatase enzyme histochemistry, cisplatin treatment induced relevant changes in the distribution pattern of enzyme activity compared with K101 or K102 treatment at 7 days after injection.

CONCLUSIONS

In conclusion, these results show that K101 is less nephrotoxic than cisplatin and a promising new platinum complex.

Intraarterial cisplatin/nedaplatin and intravenous 5-fluorouracil with concurrent radiation therapy for patients with high-risk uterine cervical cancer

OBJECTIVE

The purpose of this study was to determine the effectiveness of the combination of intraarterial and intravenous concurrent chemoradiation therapy (CIAIV-CCRT) for the treatment of high-risk uterine cervical cancer.

METHODS

Between January 2000 and November 2004, we reviewed 45 cervical cancer patients treated by CIAIV-CCRT. The numbers of patients with stage IB2, IIA, IIB, IIIA, IIIB, and IVA were 3, 6, 14, 1, 17, and 4, respectively. Patients with stage III and IVA or patients with tumors >3 cm in diameter were enrolled in this study. Two sessions of CCRT were administered every 3 weeks using a combination of 70 mg/m2 x h(-1) cisplatin or 50 mg/m2 x h(-1) nedaplatin via the bilateral uterine artery and 2800 mg/m2 x 96 h(-1) 5-fluorouracil intravenously. Patients concurrently received external beam radiation therapy and brachytherapy. A nonrandomized control group of 47 patients who underwent radiation therapy alone between 1993 and 2000 was used for comparison.

RESULTS

Of the 45 patients, 28 (62%) exhibited complete response and 16 (36%) exhibited partial response. One IIIB patient (2%) did not show any response. The 5-year overall survival (OAS) rates in the CCRT group and control group were 80.6% and 54.9%, respectively. With regard to late toxicities, no statistically significant differences were observed between the two groups. In uni- and multivariate analyses, positive pelvic lymph node showed a statistically significant influence on the OAS in the CIAIV-CCRT group (P = 0.049).

CONCLUSION

These preliminary results suggest that CIAIV-CCRT can improve the prognosis of patients with high-risk cervical cancer.

High accumulation of platinum-DNA adducts in strial marginal cells of the cochlea is an early event in cisplatin but not carboplatin ototoxicity

Ototoxicity is a typical dose-limiting side effect of cancer chemotherapy with cisplatin but much less so with carboplatin. To elucidate the underlying molecular pathological mechanisms, we have measured the formation and persistence of drug-induced DNA adducts in the nuclei of inner ear cells of guinea pigs after short-term exposure to either cisplatin or carboplatin using immunofluorescence staining and quantitative image analysis. After application of carboplatin, all cells of the cochlea exhibited a similar burden of guanine-guanine intrastrand cross-links in DNA. In contrast, we observed a pronounced 3- to 5-fold accumulation of this cytotoxic adduct exclusively in the marginal cells of the stria vascularis between 8 and 48 h after treatment with cisplatin. In the kidney, the other critical target tissue of cisplatin toxicity, a similar high preferential formation of cytotoxic DNA adducts was measured in the tubular epithelial cells but not in other renal cell types. As for the ear, this excessive formation of DNA damage in a particular cell type was seen in animals treated with cisplatin but not those treated with carboplatin. Because cisplatin ototoxicity is often attributed to oxidative stress mediated by the generation of radical oxygen species (ROS), we have measured in parallel the levels of the lead DNA oxidation product 8-oxoguanine (8-oxoG) in cochlear cryosections. Compared with basal levels in untreated control cochleas, no additional formation of 8-oxoG was detectable up to 48 h after cisplatin treatment in the DNA of either inner-ear cell type. This suggests that the generation of ROS may be a secondary event in cisplatin ototoxicity.

Agents ameliorating or augmenting the nephrotoxicity of cisplatin and other platinum compounds: a review of some recent research

Cisplatin (cis-diamminedichloroplatinum (II)) is an effective agent against various solid tumours. Despite its effectiveness, the dose of cisplatin that can be administered is limited by its nephrotoxicity. Hundreds of platinum compounds (e.g. carboplatin, oxaliplatin, nedaplatin and the liposomal form lipoplatin) have been tested over the last two decades in order to improve the effectiveness and to lessen the toxicity of cisplatin. Several agents have been tested to see whether they could ameliorate or augment the nephrotoxicity of platinum drugs. This review summarizes these studies and the possible mechanisms of actions of these agents. The agents that have been shown to ameliorate experimental cisplatin nephrotoxicity include antioxidants (e.g. melatonin, vitamin E, selenium, and many others), modulators of nitric oxide (e.g. zinc histidine complex), agents interfering with metabolic pathways of cisplatin (e.g. procaine HCL), diuretics (e.g. furosemide and mannitol), and cytoprotective and antiapoptotic agents (e.g. amifostine and erythropoietin). Only few of these agents have been tested in humans. Those agents that have been shown to augment cisplatin nephrotoxicity include nitric oxide synthase inhibitors, spironolactone, gemcitabine and others. Combining these agents with cisplatin should be avoided.

Drug-associated renal dysfunction and injury

Renal dysfunction and injury secondary to medications are common, and can present as subtle injury and/or overt renal failure. Some drugs perturb renal perfusion and induce loss of filtration capacity. Others directly injure vascular, tubular, glomerular and interstitial cells, such that specific loss of renal function leads to clinical findings, including microangiopathy, Fanconi syndrome, acute tubular necrosis, acute interstitial nephritis, nephrotic syndrome, obstruction, nephrogenic diabetes insipidus, electrolyte abnormalities and chronic renal failure. Understanding the mechanisms involved, and recognizing the clinical presentations of renal dysfunction arising from use of commonly prescribed medications, are important if injury is to be detected early and prevented. This article reviews the clinical features and basic processes underlying renal injury related to the use of common drugs.