Platinum-based Antineoplastic Drugs Research Articles

Ototoxicity among cisplatin, carboplatin, and oxaliplatin in zebrafish model.

Platinum-based antineoplastic drugs, including cisplatin, carboplatin, and oxaliplatin, are widely used in the treatment of various cancers. Ototoxicity is a common adverse effect of platinum-based drugs. Ototoxicity leads to irreversible hearing impairment. We hypothesize that different platinum-based drugs exhibit varying ototoxic concentrations, time effects, and ototoxic mechanisms. We tested this hypothesis by using a zebrafish model (pvalb3b: TagGFP) to assess the viability of hair cells collected from zebrafish larvae. Cisplatin, carboplatin, and oxaliplatin were administered at dosages of 100, 200, or 400 μM, and the ototoxic effects of these drugs were assessed 1, 2, or 3 h after administration. Fm4-64 and a TUNEL assay were used to label the membranes of living hair cells and to detect cell apoptosis, respectively. We observed that >50% of hair cells were damaged at 1 h after cisplatin (100 μM) exposure, and this ototoxic effect increased at higher dosages and over time. Owing to the smaller ototoxic effects of carboplatin and oxaliplatin, we conducted higher-strength and longer-duration experiments with these drugs. Neither carboplatin nor oxaliplatin was obviously ototoxic, even at 1600 μM and after 6 h. Moreover, only cisplatin damaged the membranes of the hair cells. Cell apoptosis and significantly increased antioxidant gene expression were observed in only the cisplatin group. In conclusion, cisplatin significantly damages sensory hair cells and has notable dosage and time effects. Carboplatin and oxaliplatin are less ototoxic than cisplatin, likely due to having different ototoxic mechanisms than cisplatin.

Empagliflozin protective effects against cisplatin-induced acute nephrotoxicity by interfering with oxidative stress and inflammation in Wistar rats.

Cisplatin (Cis) is a platinum-based antineoplastic drug used in various types of cancers. This drug can induce nephrotoxicity as a cause of acute kidney injury (AKI) by inducing oxidative stress and inflammation. Empagliflozin (Empa) is a newly developed inhibitor of sodium-glucose cotransporter-2 (SGLT2) approved as an antidiabetic medication for patients with type 2 diabetes mellitus. In addition to its blood glucose-lowering effect, Empa has been shown to exert anti-inflammatory and anti-oxidant properties. The current study aimed to investigate the protective effects of Empa on Cis-induced nephrotoxicity in rats. Male Wistar albino rats were divided into five groups, each of six rats: Sham group (received vehicle for 7 days), Control group (received vehicle for 7 days and Cis injection on day 2), Cis + Empa10 (received 10mg/kg Empa for 7 days and Cis injection on day 2), Cis + Empa30 (received 30mg/kg Empa for 7 days and Cis injection on day 2) and, Empa 30 (received 30mg/kg Empa for 7 days). One day after the last injection in each group, rats were weighed and then sacrificed to analyze the hematological, biochemical, and histological parameters. Cis markedly increased levels of inflammatory parameters such as renal tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, and myeloperoxidase (MPO) activity. Notably, malondialdehyde (MDA), blood urea nitrogen (BUN), and creatinine levels were enhanced after Cis administration. Also, the chemotherapeutic agent significantly reduced antioxidant indicators such as renal catalase (CAT), glutathione peroxidase (GpX), and superoxide dismutase (SOD). Furthermore, histopathological examinations also revealed severe renal damage following Cis treatment which was improved by Empa administration. Empa treatment at both doses (10 mg/kg and 30 mg/kg) reversed Cis-induced changes in all the above renal parameters. In conclusion, Empa has protective effects on Cis-induced nephrotoxicity by inhibition of oxidative stress and inflammation.

Multinational Retrospective Analysis of Bridging Therapy Prior to Chimeric Antigen Receptor T Cells for Relapsed/Refractory Acute Lymphoblastic Leukemia in Children and Young Adults

Background: Chimeric antigen receptor (CAR) T cells targeting CD19 are a well-established treatment option for children and young adults suffering from relapsed and/or refractory B-lineage acute lymphoblastic leukemia. Nonetheless, there is still insufficient data about the proper management of bridging therapy between eligibility for therapy and administration of CAR T cells taking into consideration that most of the patients are heavily pretreated. Bridging therapy has been designed to achieve a low leukemia burden prior to CAR T cell infusion. However, systematic data of bridging therapy are still limited and the effect of bridging therapy on outcome, side effects and response to CAR T cell therapy is still poorly understood. With this retrospective, multinational, large-scale study, we strive to understand the impact of low- and high-intensity bridging regimens on a variety of outcome parameters in order to improve the basis for clinical decision making in bridging therapy prior to CAR T cell administration. Methods: Real-world data were collected from 83 patients receiving 88 CAR T cell therapies from twelve different sites in Germany, Austria and Switzerland. Data were collected anonymously via paper case report forms and subsequently analyzed. Performed treatments were classified into the categories 1) no systemic therapy, 2) low-intensity therapy and 3) high-intensity therapy. Bridging therapies were defined as high-intensity if at least one chemotherapeutic agent of the following was given: cyclophosphamide/ifosfamide, etoposide, anthracyclines or other agents with high toxicity potential (intravenous methotrexate, platinum-based antineoplastic drugs, thiotepa, high-dose cytarabine, fludarabine). Low-intensity bridging therapies comprised the administration of steroids, vincristine, low-dose cytarabine, PEG-asparaginase/Erwinia asparaginase and oral maintenance therapy (mercaptopurine, thioguanine, oral methotrexate, hydroxyurea). The administration of specific chemotherapeutic agents as well as immunotherapies and targeted therapies was assessed. CAR therapies comprised CD19 2 nd generation CAR T cell products from commercial and academic providers. We then analyzed the impact of different bridging regimens on several outcome parameters such as overall and disease-free survival, adverse events, tumor burden and performance status at defined time points (eligibility, leukapheresis if performed, lymphodepletion/CAR T cell infusion). Results: 33 of 88 treatments were classified as high-intensity and 34 as low-intensity bridging regimens. Prior to 13 CAR T cell administrations no systemic bridging therapy was given, 8 of 88 bridging regimens could not be stratified due to incomplete data (Figure 1). Between eligibility and apheresis, mostly low-intensity therapy or no systemic therapy was given. Within the period between apheresis and CAR T cell infusion, treatment diversified due to the heterogeneity of the cohort. Patient characteristics are listed in Table 1. Patients receiving a high-intensity bridging therapy had a significantly higher tumor burden at time point of eligibility defined by blasts in bone marrow and by measurement of minimal residual disease (MRD) compared to patients treated with a low-intensity or no systemic bridging therapy. Tumor burden within the two groups converged over the time of bridging therapy. However, at time of lymphodepletion, patients in the high-intensity group showed a significantly lower performance status indicated by Karnofsky/Lansky score than patients in the low-intensity/no systemic therapy group, reflecting the higher toxicity potential. Furthermore, these patients suffered significantly more often from bacterial adverse events and mucositis. Neither overall nor disease-free survival differed significantly between the two bridging regimen groups. Conclusion: In this retrospective cohort data, a high-intensity bridging therapy has not improved the outcome of CAR T cell therapy in terms of overall and disease-free survival. Yet high-intensity bridging therapy has caused more mucositis, bacterial adverse events and worsened the performance status. Our study suggests that a low-intensity bridging regimen may be preferred whenever tumor burden and disease kinetics allow this treatment strategy.

Platinum-based chemotherapy induces demyelination of Schwann cells in oral squamous cell carcinoma treatment

BackgroundCisplatin, carboplatin, and oxaliplatin are the only three platinum-based antineoplastic drugs that have been accepted worldwide for treating various cancers. Up to 83.6% of patients treated with platinum-based antineoplastic drugs will develop chemotherapy-induced peripheral neuropathy (CIPN), manifesting as sensory paresthesias, dysesthesias, and hypoesthesias that can cause significant adverse impact to daily activities. AimTo investigate how these three platinum-based drugs affect mitochondrial function and myelination state of Schwann cells and the signalling pathway involved. Method2 μM Cisplatin, 20 μM carboplatin, and 1 μM oxaliplatin were used to inhibit the growth of CAL-27 by 20% respectively. These drugs were then used to induce chemotherapy-induced peripheral neuropathy in Rat Schwann Cells (RSC96). The changes in cell metabolism and myelin formation in RSC96 were investigated. ResultCisplatin and carboplatin, but not oxaliplatin increased intracellular and mitochondrial reactive oxygen species in RSC96. Only Cisplatin and carboplatin decreased mitochondrial membrane potential (ΔΨm) and ATP production in RSC96. Both Cisplatin and carboplatin led to demyelination of RSC96, characterized by increased expression of p75NTR and decreased expression of myelin protein zero (MPZ). ConclusionCisplatin and carboplatin, but not oxaliplatin, caused mitochondrial dysfunction and induced demyelination in RSC96 while showing similar toxicity to head and neck cancer cells. Oxaliplatin may be a potential chemotherapy drug to prevent CIPN in patients with head and neck cancer.

The role of platinum-based antineoplastic drugs and their impact on complete pathological response and prognosis in patients with BRCA-associated triple-negative breast cancer after neoadjuvant treatment: a single institution experience

Background. BRCA-associated triple negative breast cancer (TNBC) is considered one of the most aggressive subtypes of breast cancer with high sensitivity to chemotherapy, which leads to increased interest in finding new treatment options for patients with this subtype of breast cancer. Aim. To determine the role of adding a platinum drug to standard systemic neoadjuvant therapy (NAC) for patients with primary BRCA-associated TNBC with clinical stage T1–3N0–3M0, and to evaluate the effect of platinum-based drugs on recurrence-free survival in patients of this category. Materials and methods. The study included 75 patients diagnosed with primary BRCA-associated TNBC. They were divided into 2 groups depending on the NAC provided, and then they were subdivided depending on the completion of the course of ongoing NAC, the final pathomorphological result and the presence of recurrence. Results. Group I included 48 (64 %) patients who received the AC–T regimen; in group II (n = 27 (36 %)) patients received NAC according to the AC–TCarb regimen. Patients of group II showed a higher frequency of achieving pathological complete response (pCR) compared with patients of group I (73.7 % versus 41.2 %, respectively, p = 0.0433). Taking into account the NAC regimens being carried out, patients of group I had a slightly higher risk of recurrence compared to patients of group II (p = 0.099). Conclusion. In patients with primary BRCA-associated TNBC, the addition of platinum compounds to the systemic NAC resulted in achieving of pCR in 73.7 % cases compared with 41.2 % pCR after the standard anthracycline-taxane NAC, which entails a reduced risk recurrence in this category of patients. Performing a full course of planned NAC has a positive trend in achieving pCR in patients of this category.

Liver cirrhosis following oxaliplatin-based adjuvant chemotherapy for rectal cancer.

Oxaliplatin is a third-generation platinum-based antineoplastic drug that is widely used to treat patients with colorectal cancer. Reported adverse reactions include hepatic sinusoidal obstruction syndrome and liver fibrosis, but there are few reports of cirrhosis associated with chemotherapy. In addition, the pathogenesis of cirrhosis remains unclear. We report a case of suspected oxaliplatin-induced liver cirrhosis, an adverse reaction that has not been previously reported. A 50-year-old Chinese man was diagnosed with rectal cancer and underwent laparoscopic radical rectal cancer surgery. The patient had a history of schistosomiasis, but history and serology showed no evidence of chronic liver disease. However, after five oxaliplatin-based chemotherapy cycles, the patient presented dramatic changes in liver morphology and developed splenomegaly, massive ascites, and elevated CA125 levels. Four months after discontinuing oxaliplatin, the patient's ascites had decreased significantly and CA125 levels declined from 505.3 to 124.6 mU/mL. After 15 weeks of follow-up, CA125 levels decreased to the normal range, and there has been no increase in ascites in this patient. Oxaliplatin-induced cirrhosis may be a serious complication and should be discontinued based on clinical evidence.

Precise quantitative evaluation of pharmacokinetics of cisplatin using a radio-platinum tracer in tumor-bearing mice.

ObjectiveThe platinum-based antineoplastic drug cisplatin is commonly used for chemotherapy in clinics. This work aims to demonstrate a radio-platinum tracer is useful for precisely quantifying small amounts of platinum in pharmacokinetics studies.MethodsA cisplatin radiotracer (radio-cisplatin) was synthesized, and a comprehensive evaluation of cisplatin over 7 days after its intravenous injection into nude mice bearing a subcutaneous lung tumor (H460) was conducted.ResultsA biphasic retention curve in the whole body and blood was observed [T1/2(α) = 1.14 h, T1/2(β) = 5.33 days for the whole body, and T1/2(α) = 23.9 min, T1/2(β) = 4.72 days for blood]. The blood concentration decreased within 1 day after injection. Most of the intact cisplatin was excreted via the kidneys in the early time points, and a small part was distributed in tissues including tumors. The plasma protein binding rate of cisplatin increased rapidly after injection, and the protein-bound cisplatin remained in the blood longer than intact cisplatin. The peak uptake in H460 tumors was 4.7% injected dose per gram at 15 min after injection, and the area under the curve (AUC0–7 days) was approximately one-half to one-third of the AUC0–7 days in the kidneys, liver, and bone, where some toxicity is observed in humans.ConclusionThe radio-platinum tracer revealed the highly quantitative biodistribution of cisplatin, providing insights into the properties of cisplatin, including its adverse effects. The tracer enables a precise evaluation of pharmacokinetics for platinum-based drugs with high sensitivity.

Effective Perturbations by Small-Molecule Modulators on Voltage-Dependent Hysteresis of Transmembrane Ionic Currents.

The non-linear voltage-dependent hysteresis (Hys(V)) of voltage-gated ionic currents can be robustly activated by the isosceles-triangular ramp voltage (Vramp) through digital-to-analog conversion. Perturbations on this Hys(V) behavior play a role in regulating membrane excitability in different excitable cells. A variety of small molecules may influence the strength of Hys(V) in different types of ionic currents elicited by long-lasting triangular Vramp. Pirfenidone, an anti-fibrotic drug, decreased the magnitude of Ih’s Hys(V) activated by triangular Vramp, while dexmedetomidine, an agonist of α2-adrenoceptors, effectively suppressed Ih as well as diminished the Hys(V) strength of Ih. Oxaliplatin, a platinum-based anti-neoplastic drug, was noted to enhance the Ih’s Hys(V) strength, which is thought to be linked to the occurrence of neuropathic pain, while honokiol, a hydroxylated biphenyl compound, decreased Ih’s Hys(V). Cell exposure to lutein, a xanthophyll carotenoid, resulted in a reduction of Ih’s Hys(V) magnitude. Moreover, with cell exposure to UCL-2077, SM-102, isoplumbagin, or plumbagin, the Hys(V) strength of erg-mediated K+ current activated by triangular Vramp was effectively diminished, whereas the presence of either remdesivir or QO-58 respectively decreased or increased Hys(V) magnitude of M-type K+ current. Zingerone, a methoxyphenol, was found to attenuate Hys(V) (with low- and high-threshold loops) of L-type Ca2+ current induced by long-lasting triangular Vramp. The Hys(V) properties of persistent Na+ current (INa(P)) evoked by triangular Vramp were characterized by a figure-of-eight (i.e., ∞) configuration with two distinct loops (i.e., low- and high-threshold loops). The presence of either tefluthrin, a pyrethroid insecticide, or t-butyl hydroperoxide, an oxidant, enhanced the Hys(V) strength of INa(P). However, further addition of dapagliflozin can reverse their augmenting effects in the Hys(V) magnitude of the current. Furthermore, the addition of esaxerenone, mirogabalin, or dapagliflozin was effective in inhibiting the strength of INa(P). Taken together, the observed perturbations by these small-molecule modulators on Hys(V) strength in different types of ionic currents evoked during triangular Vramp are expected to influence the functional activities (e.g., electrical behaviors) of different excitable cells in vitro or in vivo.

P-1 Potential neuroprotective effects of losartan and donepezil on oxaliplatin-induced peripheral neuropathy in rats

Oxaliplatin (OXL) is a platinum-based antineoplastic drug widely used for treating colorectal cancer which induces peripheral neuropathy as dose-limiting toxicity. We assess the neuroprotective effects of losartan (LOS) and donepezil (DPZ) on OXL-induced peripheral neuropathy in rats. Forty Sprague-Dawley rats were divided into four groups; control (vehicle-treated), OXL (2.4 mg/kg/d; intraperitoneal), OXL+LOS (100 mg/kg/d; oral), and OXL+DPZ (1 mg/kg/d; oral). All were given 5 times/week for 2 weeks. Behavioral assessment of pain, sensory, and motor disturbances was done on days 7 and 14 using a paintbrush, acetone, tail-flick latency, and grip strength tests. The levels of interleukin (IL)-1β, and tumor necrosis factor (TNF)-α were measured in L4-L6 samples. Histopathological examination of the sciatic nerve was done to assess nerve degeneration. OXL induced significant mechanical dynamic allodynia, cold allodynia, and thermal hyperalgesia compared to the control group. LOS significantly ameliorated mechanical and cold allodynia, while DPZ improved mechanical allodynia and thermal hyperalgesia. OXL significantly increased IL-1β, and TNF-α compared to the control group. Only LOS significantly attenuated these markers. In the OXL group, the axons were swollen, and nerve fiber degeneration with neuron gaps occurred. Both treatments improved these histopathological changes. LOS and DPZ attenuate the neurotoxic effect of oxaliplatin by attenuating behavioral and histopathological alterations and the protective effect of LOS may involve in the inhibition of spinal pro inflammatory cytokines. Therefore, LOS and DPZ are promising agents to prevent OXA-induced peripheral neuropathy.

Translation inhibition and suppression of stress granules formation by cisplatin.

Platinum-based antineoplastic drugs, such as cisplatin, are commonly used to induce tumor cell death. Cisplatin is believed to induce apoptosis as a result of cisplatin-DNA adducts that inhibit DNA and RNA synthesis. Although idea that DNA damage underlines anti-proliferative effects of cisplatin is dominant in cancer research, there is a poor correlation between the degree of the cell sensitivity to cisplatin and the extent of DNA platination. Here, we examined possible effects of cisplatin on post-transcriptional gene regulation that may contribute to cisplatin-mediated cytotoxicity. We show that cisplatin suppresses formation of stress granules (SGs), pro-survival RNA granules with multiple roles in cellular metabolism. Mechanistically, cisplatin inhibits cellular translation to promote disassembly of polysomes and aggregation of ribosomal subunits. As SGs are in equilibrium with polysomes, cisplatin-induced shift towards ribosomal aggregation suppresses SG formation. Our data uncover previously unknown effects of cisplatin on RNA metabolism.

Characterization and Separation of Platinum-Based Antineoplastic Drugs by Zwitterionic Hydrophilic Interaction Liquid Chromatography (HILIC)–Tandem Mass Spectrometry, and Its Application in Surface Wipe Sampling

Platinum-based antineoplastic drugs (PtADs) are among the most important and used families of chemotherapy drugs, which, even showing severe side effects and being hindered by drug resistance, are not likely to be replaced clinically any time soon. The growing interest in the occupational health community in antineoplastic drug (AD) surface contamination requires the development of increasingly fast and easy high-throughput monitoring methods, even considering the lack of harmonized legally binding regulation criteria. Thus, a wipe sampling method together with zwitterionic hydrophilic interaction liquid chromatography (HILIC-Z)–tandem mass spectrometry (MS/MS) analysis was developed for the simultaneous evaluation of oxaliplatin, cisplatin, and carboplatin surface contaminations. A design of experiments approach was used to optimize the chromatographic conditions. Limits of quantification ranging from 2 to 5 ng/mL were obtained from interday and intraday repetitions for oxaliplatin and carboplatin, and between 170 and 240 ng/mL for cisplatin. The wipe desorption procedure is equivalent to other AD sampling methods, enabling a fast sample preparation, with an LC-MS/MS analysis time of less than 7 min.

Evaluation of toxic effects of platinum-based antineoplastic drugs (cisplatin, carboplatin and oxaliplatin) on green alga Chlorella vulgaris

Platinum-based antineoplastic drugs (PBADs) enter the environment via hospital and municipal wastes as reactive and highly toxic molecules. Chlorella vulgaris is a freshwater microalgae and is used as an excellent aquatic model for toxicity assessment. In the present study, the toxicity of PBADs to C. vulgaris was investigated for better understanding of PBADs environmental toxicity. The algae were cultured in Bold´s Basal Medium (BBM) and exposed to different concentrations of PBADs for 48, 72 and 96 h. Then, cell proliferation, the synthesis of photosynthetic pigments, protein content, malondialdehyde (MDA) release and antioxidant potential were determined. IC50 s of cisplatin, carboplatin and oxaliplatin for 96 h of exposure were 106.2, 124.3 and 153.9 mg/L respectively. Cell proliferation, synthesis of chlorophyll a, chlorophyll b and algal protein content significantly decreased in a time and dose-dependent manner. The release of MDA to culture media significantly increased and antioxidant potential decreased.Cisplatin showed more toxic effects on C. vulgaris compared to carboplatin and oxaliplatin indicating its severe toxicity for marine organisms. PBADs induce their toxic effects in algal cells via the interaction with DNA, production of free radicals (such as reactive oxygen species), lipid peroxidation and cell wall damages. Due to these toxic effects of PBADs for various environmental organisms, there must be severe restriction on their release into the environment.

Neuroprotective effect of alogliptin on oxaliplatin-induced peripheral neuropathy in vivo and in vitro

Oxaliplatin is a platinum-based antineoplastic drug commonly used for treating colorectal, gastric, and pancreatic cancer. However, it frequently causes peripheral neuropathy as dose-limiting toxicity and is lacking a strategy for prevention. Alogliptin, a dipeptidyl peptidase 4 (DPP-4) inhibitor, is an oral antidiabetic drug. Previous studies have shown that DPP-4 inhibitors have pleiotropic effects, including neuroprotection. In this study, we investigated the effects of alogliptin on oxaliplatin-induced peripheral neuropathy using in vitro and in vivo models. In PC12 cells, alogliptin attenuated neurite disorders induced by oxaliplatin and cisplatin. The repeated injection of oxaliplatin caused mechanical allodynia and axonal degeneration of the sciatic nerve in rats. These neuropathies were ameliorated by co-administration of alogliptin. Moreover, alogliptin did not attenuate tumor cytotoxicity of oxaliplatin in the cultured colon, gastric, or pancreatic cancer cell lines and tumor-bearing mice. These findings suggest that alogliptin may be beneficial for preventing oxaliplatin-induced peripheral neuropathy.

Simple Trans-Platinum Complex Bearing 3-Aminoflavone Ligand Could Be a Useful Drug: Structure-Activity Relationship of Platinum Complex in Comparison with Cisplatin.

Following previous studies devoted to trans–Pt(3-af)2Cl2, in this paper, the molecular structure and intermolecular interactions of the title complex are compared with other cisplatin analogues of which the crystal structures are presented in the Cambridge Structural Database (CSD). Molecular Hirshfeld surface analysis and computational methods were used to examine a possible relationship between the structure and anticancer activity of trans–Pt(3-af)2Cl2. The purpose of the article was also to investigate the effect of hyperthermia on the anticancer activity of cisplatin, cytostatics used in the treatment of patients with ovarian cancer and a new analogue of cisplatin-trans–Pt(3-af)2Cl2. The study was conducted on two cell lines of ovarian cancer sensitive to Caov-3 cytostatics and the OVCAR-3 resistant cisplatin line. The study used the MTT (3-(4,5-dimethylthiazol-2,5-diphenyltetrazolium bromide) cell viability assay, LDH (lactate dehydrogenase), and the quantitative evaluation method for measuring gene expression, i.e., qPCR with TagMan probes. Reduced survivability of OVCAR-3 and Caov-3 cells exposed to cytostatics at elevated temperatures (37 °C, 40 °C, 43 °C) was observed. Hyperthermia may increase the sensitivity of cells to platinum-based antineoplastic drugs and paclitaxel, which may be associated with the reduction of gene expression related to apoptotic processes.

RgIA4 Accelerates Recovery from Paclitaxel-Induced Neuropathic Pain in Rats.

Chemotherapeutic drugs are widely utilized in the treatment of human cancers. Painful chemotherapy-induced neuropathy is a common, debilitating, and dose-limiting side effect for which there is currently no effective treatment. Previous studies have demonstrated the potential utility of peptides from the marine snail from the genus Conus for the treatment of neuropathic pain. α-Conotoxin RgIA and a potent analog, RgIA4, have previously been shown to prevent the development of neuropathy resulting from the administration of oxaliplatin, a platinum-based antineoplastic drug. Here, we have examined its efficacy against paclitaxel, a chemotherapeutic drug that works by a mechanism of action distinct from that of oxaliplatin. Paclitaxel was administered at 2 mg/kg (intraperitoneally (IP)) every other day for a total of 8 mg/kg. Sprague Dawley rats that were co-administered RgIA4 at 80 µg/kg (subcutaneously (SC)) once daily, five times per week, for three weeks showed significant recovery from mechanical allodynia by day 31. Notably, the therapeutic effects reached significance 12 days after the last administration of RgIA4, which is suggestive of a rescue mechanism. These findings support the effects of RgIA4 in multiple chemotherapeutic models and the investigation of α9α10 nicotinic acetylcholine receptors (nAChRs) as a non-opioid target in the treatment of chronic pain.

Comparison of effects of UGT1A1*6 and UGT1A1*28 on irinotecan-induced adverse reactions in the Japanese population: analysis of the Biobank Japan Project.

It has been reported that there are differences in effects on irinotecan-induced adverse reactions between UGT1A1*6 and UGT1A1*28. In order to compare those differences in the Japanese population, we examined the associations between UGT1A1 and irinotecan-induced adverse reactions using the BioBank Japan Project database. We genotyped UTG1A1*6 and UGT1A1*28 and conducted case-control analyses. A total of 651 patients (102 cases and 549 tolerant controls) were included in this study. The results showed that UGT1A1*6/*6 is a predictor of adverse drug reactions (ADRs) (p-value 0.00070, odds ratio 6.59, 95% confidence interval 2.33-18.6), whereas UGT1A1*6/*28 and UGT1A1*28/*28 were not. The subanalysis comprising only patients with UGT1A1*6/*6, UGT1A1*6/*28, and UGT1A1*28/*28 revealed a trend towards an increased risk of ADRs in patients with UGT1A1*6 (p-value 0.0092, odds ratio 4.39, 95% confidence interval 1.57-14.9). Multiple logistic regression analyses showed that use of platinum-based antineoplastic drugs and presence of UGT1A1*6/*6 were independent variables, significantly associated with ADRs. The diagnostic performance of a predictive model had a sensitivity of 49.0%, specificity of 70.1%, and a number needed to screen of 5.8. We concluded that UGT1A1 testing could be useful to predict irinotecan-induced ADRs, and that UTG1A1*6 rather than UGT1A1*28 contributed to ADR occurrence.

Effectiveness of Neoadjuvant Therapy with Platinum-Based Agents for Patients with BRCA1 and BRCA2 Germline Mutations - A Retrospective Analysis of Breast Cancer Patients Treated at MMCI Brno.

Mutations in the BRCA1 and BRCA2 genes are associated with a high risk of developing breast cancer. Tumors arising from this mutation are expected to be more sensitive to platinum-based drugs. The role of platinum-based drugs in systemic neoadjuvant BRCA1/2 breast cancer therapy, and its efficacy in increasing the probability of pathological complete remission (pCR) are discussed repeatedly; however, there are no clear recommendations. We retrospectively evaluated the contribution of a platinum-based antineoplastic drug to the achievement of pCR in a set of patients with BRCA1/2 mutant breast cancer treated with neoadjuvant chemotherapy from 2010 to 2017. The response to neoadjuvant chemotherapy was evaluated by a pathologist using definitive surgical specimens. A pCR was defined as a condition in which complete invasive breast cancer, and (eventually) positive lymph nodes, had disappeared. Of 76 patients (median age, 39 years; 62% with triple negative breast cancer (TNBC); 70% with BRCA1 positivity), 37 were treated with platinum-based drugs. More patients treated with platinum derivatives achieved pCR (57% vs. 23%, p = 0.005). Patients treated in a neoadjuvant setting with platinum-based antineoplastic drugs had a 4.4× greater chance of achieving pCR than those not treated with platinum, assuming the same tumor phenotype (TNBC or SR+/HER2). Neoadjuvant platinum-based chemotherapy for patients with a BRCA1/2 mutation is associated with a higher probability of achieving pCR, which is important for subsequent prognosis. This treatment should be considered particularly for patients with BRCA1 mutation and a TNBC phenotype. This work was supported by grant of the Ministry of Health of the Czech Republic - Conceptual. Development of a Reaserch Organization (MMCI 00209805). This work was supported by grant of the Ministry of Education, Youth and Sport of the Czech Republic (NPU I - LO1413). The authors declare they have no potential confl icts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Submitted: 21. 3. 2019 Accepted: 14. 5. 2019.

Abstract SY28-04: Obesity-associated leptin signaling promotes chemotherapy resistance in triple-negative breast cancer: The role of tumor-initiating cell enrichment

Abstract SY28-04: Obesity-associated leptin signaling promotes chemotherapy resistance in triple-negative breast cancer: The role of tumor-initiating cell enrichment

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

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

GSTP1 as a potential predictive factor for adverse events associated with platinum-based antitumor agent-induced peripheral neuropathy.

Glutathione S-transferase (GST) exhibits antidotal effects on numerous drugs, including platinum-based antineoplastic drugs. Furthermore, GST Pi 1 (GSTP1) polymorphism is associated with peripheral neuropathy. In the present study, it was determined whether GSTP1 can predict adverse events associated with platinum-based antitumor agent-induced peripheral neuropathy among Japanese patients. The subjects included 122 patients, among whom 105 patients had colorectal, 16 had gastric, and one patient had pancreatic cancer. It was indicated that wild type (AA) GSTP1 was expressed in 99 patients (81.1%), whereas heterozygous (AG) and homozygous (GG) GSTP1 polymorphisms were present in 22 (18.0%) and 1 (0.8%) patients, respectively. Among patients with colorectal cancer, the expression of homozygous GSTP1 was observed in 88 patients (83.8%), whereas that of heterozygous GSTP1 was observed in 17 patients (16.2%). Peripheral neuropathy of grade ≥3 occurred in 10 patients (9.5%) receiving mFOLFOX therapy (a biweekly cycle consisting of a 2-h infusion of 85 mg/m2 oxaliplatin and 200 mg/m2 leucovorin followed by a bolus administration of 400 mg/m2 5-fluorouracil and a continuous 48-h infusion of 2,400 mg/m2 5-fluorouracil) for colorectal cancer, which included 6 patients with the AA allele (6.8%) and 4 patients with the AG allele (23.5%). The number of peripheral neuropathy cases of grade ≥3 was increased among patients with the AG allele, compared with patients with the AA allele (P=0.032). In patients with gastric cancer, the AA and AG types of GSTP1 were expressed in 11 (68.8%) and 5 (31.2%) patients, respectively. Cisplatin, administered to patients with gastric cancer, did not induce peripheral neuropathy. The aforementioned indicated that GSTP1 genetic polymorphism is associated with peripheral neuropathy induced by oxaliplatin treatment for colorectal cancer, and therefore serves as a predictive marker. Furthermore, early dose reduction or drug withdrawal should be implemented depending on the severity of peripheral neuropathy as a potential method for reducing the number of patients discontinuing the drug, due to adverse events involving peripheral neuropathy.