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Objectives: Evaluate factors associated with adherence to ototoxicity monitoring among patients with head and neck cancer treated with cisplatin and radiation therapy at a tertiary care center. Methods: We performed a single‐institution retrospective cohort study on adults with head and neck cancer treated with cisplatin and radiation therapy who participated in an ototoxicity monitoring program. The primary outcomes were rates of post‐treatment audiograms at the following time points: one, three, six, 12, and greater than 12 months. Multivariable logistic regression was performed to identify risk factors associated with complete loss of follow‐up after pre‐treatment evaluation. Results: Two hundred ninety‐four head and neck cancer patients were analyzed. Overall, 220 (74.8%) patients had at least one post‐treatment audiogram; 58 (20.0%) patients had more than one audiogram. The time point with the highest follow‐up rate was at 3 months (n = 170, 57.8%); rates at the remaining times ranged from 7.1% to 14.3%. When controlling for covariates, patients without insurance and those with stage IV cancers were associated with complete loss of audiologic follow‐up (aOR = 7.18, 95% CI = 2.75–19.90; aOR = 1.96, 95% CI = 1.02–3.77, respectively). Among 156 patients recommended for a hearing aid, only 39 (24.8%) patients received one. Conclusions: Head and neck cancer patients enrolled in an ototoxicity monitoring program demonstrate moderately high follow‐up rates for at least one post‐treatment audiogram. However, follow‐up tapers dramatically after 6 months, and overall hearing aid utilization is low. Further research is needed to understand barriers to long‐term audiologic follow‐up and hearing aid utilization to decrease untreated hearing loss in cancer survivorship. Level of Evidence: Level 3 Laryngoscope, 133:3161–3168, 2023 [ABSTRACT FROM AUTHOR]

Objective: To explore whether deintensification of adjuvant therapy reduces ototoxicity among patients with human papillomavirus (HPV)‐related oropharyngeal squamous cell carcinoma (OPSCC). Study Design: Retrospective cohort study. Setting: Single academic center. Methods: The ototoxicity rate among adult patients with HPV‐related OPSCC enrolled in the Minimalist Trial (MINT), a prospective phase 2 trial of surgery followed by risk‐adjusted deintensified adjuvant therapy (42 Gy radiation given alone or with a single 100 mg/m2 dose of cisplatin), was compared to that among a historical cohort treated with standard adjuvant therapy (60‐66 Gy radiation with up to three 100 mg/m2 doses of cisplatin). Ototoxicity was defined as Common Terminology Criteria for Adverse Events v5.0 ≥ Grade 2. Mixed model analysis was performed to investigate the association between deintensified adjuvant therapy and treatment‐related hearing loss. Results: A total of 29 patients (58 ears) were analyzed in the MINT cohort, and 27 patients (54 ears) in the historical cohort. The ototoxicity rate was 5% (n = 3/58 ears) in the MINT cohort and 46% (n = 25/54 ears) in the historical cohort (difference, 41%; 95% confidence interval [CI] = 27%‐56%). Patients in the MINT cohort demonstrated a 95% decrease in risk of ototoxicity compared to those in the historical cohort (adjusted odds ratio: 0.05, 95% CI = 0.01‐0.31). Differences in estimated marginal mean threshold shifts were statistically and clinically significant at frequencies ≥ 3 kHz. Conclusion: The deintensified adjuvant therapy given in MINT led to less ototoxicity than standard adjuvant therapy among patients with HPV‐related OPSCC. [ABSTRACT FROM AUTHOR]

Introduction Platinum-based chemotherapeutic agents cisplatin and carboplatin are two of the most widely used drugs in cancer today. They display wide range of adverse reactions; among them, ototoxicity is an important cumulative toxicity that more commonly observed with cisplatin. At a later stage, it can affect speech of individual and lead to communication problem with decreased cognitive function and depression in cancer survivors. Periodic monitoring of hearing loss with pure-tone audiometry (PTA) provides early evidence of ototoxicity which may decrease debilitating effect of the same in a patient. Objective The primary objective of this study was to assess cisplatin-induced ototoxicity. We also investigated its severity, reversibility, and other modifying risk factors. Materials and Methods We conducted a prospective observational descriptive type of epidemiological study. The study was conducted over 80 randomly selected cancer patients (for estimation of sample size, the following formula was used n = [Zα² PQ] /d²), who were starting with their first cycle of cisplatin from August 2018 to July 2020. This study was conducted at tertiary cancer care center in western Gujarat which caters patients from all over India. We performed PTA in all randomized patients at baseline and periodically.We classified hearing loss according to theWorld Health Organization (WHO) criteria. Results A total of 30% (n = 24) patients developed cisplatin-induced ototoxicity according to WHO criteria at end of 3 months after starting the first cycle of cisplatin. It was sensory neuronal, affecting both the ears equally, and was seen predominantly at high frequency. We observed hearing loss at 3 months to be significantly more common in the 301 to 400mg/m² cumulative dose group (47%), as compared with the other two groups (0-200 mg/m² and 201-300 mg/m²; p<0.05). It showed dose dependency with cisplatin. In the multivariate step-wise regression model, baseline hearing loss (odds ratio [OR] = 17.71, 95% confidence interval [CI]: 6.57-118.91, p<0.05) and cumulative cisplatin dose of more than 300 mg/m² were significantly associated with hearing loss at 3 months (OR = 6.62, 95% CI: 2.33-18.74, p<0.05). [ABSTRACT FROM AUTHOR]

Abstract Background Cisplatin 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). Methods This 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. Results All 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. Conclusion This 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 is a lifesaving chemotherapeutic drug with marked ototoxic adverse effects. Cisplatin-induced hearing loss affects a significant part of cancer-surviving patients and is an unmet clinical need with important socioeconomic consequences. Unfortunately, in current preclinical animal models of cisplatin ototoxicity, which are mainly based on systemic delivery, important morbidity is observed, leading to premature death. This methodology not only raises obvious animal welfare concerns but also increases the number of animals used in ototoxicity studies to compensate for dropouts related to early death. To overcome these important limitations, we developed a local delivery model based on the application of a cisplatin solution directly into the otic bulla through a retroauricular approach. The local delivery model reliably induced significant hearing loss with a mean threshold shift ranging from 10 to 30 dB, strongly affecting the high frequencies (22 and 32 kHz). Importantly, mice did not show visible stress or distress indicators and no significant morbidity in comparison with a traditional systemic delivery control group of mice injected intraperitoneally with 10 mg/kg cisplatin, where significant weight loss >10% in all treated animals (without any recovery) led to premature abortion of experiments on day 3. Mass spectrometry confirmed the absence of relevant systemic uptake after local delivery, with platinum accumulation restricted to the cochlea, whereas important platinum concentrations were detected in the liver and kidney of the systemic cisplatin group. A clear correlation between the cochlear platinum concentration and the auditory threshold shift was observed. Immunohistochemistry revealed statistically significant loss of outer hair cells in the basal and apical turns of the cochlea and an important and statistically significant loss of auditory neurons and synapses in all cochlear regions. In conclusion, local cisplatin delivery induces robust hearing loss with minimal morbidity, thereby offering a reliable rodent model for human cisplatin ototoxicity, reducing the number of animals required and showing improved animal welfare compared with traditional systemic models.

Cisplatin is a lifesaving chemotherapeutic drug with marked ototoxic adverse effects. Cisplatin-induced hearing loss affects a significant part of cancer-surviving patients and is an unmet clinical need with important socioeconomic consequences. Unfortunately, in current preclinical animal models of cisplatin ototoxicity, which are mainly based on systemic delivery, important morbidity is observed, leading to premature death. This methodology not only raises obvious animal welfare concerns but also increases the number of animals used in ototoxicity studies to compensate for dropouts related to early death. To overcome these important limitations, we developed a local delivery model based on the application of a cisplatin solution directly into the otic bulla through a retroauricular approach. The local delivery model reliably induced significant hearing loss with a mean threshold shift ranging from 10 to 30 dB, strongly affecting the high frequencies (22 and 32 kHz). Importantly, mice did not show visible stress or distress indicators and no significant morbidity in comparison with a traditional systemic delivery control group of mice injected intraperitoneally with 10 mg/kg cisplatin, where significant weight loss >10% in all treated animals (without any recovery) led to premature abortion of experiments on day 3. Mass spectrometry confirmed the absence of relevant systemic uptake after local delivery, with platinum accumulation restricted to the cochlea, whereas important platinum concentrations were detected in the liver and kidney of the systemic cisplatin group. A clear correlation between the cochlear platinum concentration and the auditory threshold shift was observed. Immunohistochemistry revealed statistically significant loss of outer hair cells in the basal and apical turns of the cochlea and an important and statistically significant loss of auditory neurons and synapses in all cochlear regions. In conclusion, local cisplatin delivery induces robust hearing loss with minimal morbidity, thereby offering a reliable rodent model for human cisplatin ototoxicity, reducing the number of animals required and showing improved animal welfare compared with traditional systemic models. [ABSTRACT FROM AUTHOR]

Background: Cisplatin 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).Methods: This 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.Results: All 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.Conclusion: This 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. [ABSTRACT FROM AUTHOR]

Cisplatin is used in a wide variety of malignancies, but cisplatin-induced ototoxicity remains a major issue in clinical practice. Experimental evidence indicates that ferroptosis plays a key role in mediating the unwanted cytotoxicity effect caused by cisplatin. However, the role of ferroptosis in cisplatin-induced ototoxicity requires elucidation. Ferrostatin-1 (Fer-1) was identified as a potent inhibitor of ferroptosis and radical-trapping antioxidant with its ability to reduce the accumulation of lipid peroxides and chain-carrying peroxyl radicals. In the current study, we investigated the effects of Fer-1 in cisplatin-induced ototoxicity in in vitro , ex vivo , and in vivo models. We found, for the first time that Fer-1 efficiently alleviated cisplatin-induced cytotoxicity in HEI-OC1 cells via a concentration-dependent manner. Furthermore, Fer-1 mitigated cisplatin cytotoxicity in transgenic zebrafish sensory hair cells. In HEI-OC1 cells, Fer-1 pretreatment not only drastically reduced the generation of intracellular reactive oxygen species but also remarkably decreased lipid peroxidation levels induced by cisplatin. This was not only ascribed to the inhibition of 4-hydroxynonenal, the final product of lipid peroxides, but also to the promotion of glutathione peroxidase 4, the protein marker of ferroptosis. MitoTracker staining and transmission electron microscopy of mitochondrial morphology suggested that in HEI-OC1 cells, Fer-1 can effectively abrogate mitochondrial damage resulting from the interaction with cisplatin. In addition, Fer-1 pretreatment of cochlear explants substantially protected hair cells from cisplatin-induced damage. Therefore, our results demonstrated that ferroptosis might be involved in cisplatin ototoxicity. Fer-1 administration mitigated cisplatin-induced hair cell damage, further investigations are required to elucidate the molecular mechanisms of its otoprotective effect. • We proved that Fer-1 inhibited cisplatin-induced ototoxicity. • A novel zebrafish model was used for proving the effect of Fer-1. • Fer-1 pretreatment reduced ROS generation and lipid peroxidation levels. • We proved that glutathione peroxidase 4 was upregulated by Fer-1. • Fer-1 treatment prevented cisplatin-induced ferroptotic mitochondrial damage. [ABSTRACT FROM AUTHOR]

Xueling Wang,1–3,* Yuming Chen,1–3,* Yong Tao,1–3 Yunge Gao,1–3 Dehong Yu,1–3 Hao Wu1–3 1Department of Otolaryngology-Head and Neck Surgery, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China; 2Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China; 3Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, People’s Republic of China *These authors contributed equally to this work Background: The delivery of treatment agents to inner ear with drug delivery system (DDS) has been under investigation to overcome the limitations of the conventional therapeutic agents in curing or alleviating the cisplatin ototoxicity.Methods: In the present study, a novel targeted dexamethasone (DEX)-loaded DDS, A666-DEX-NP, was constructed for prevention from cisplatin-induced hearing loss. A666-(CLEPRWGFGWWLH) peptides specifically bind to prestin, which is limited to the outer hair cells (OHCs). HEI-OC1 and cisplatin-treated guinea pigs (12 mg/kg, intraperitoneal) were used as in vitro and in vivo models for investigating the targeting and protective efficiency against cisplatin.Results: As expected, compared to A666-unconjugated nanoparticles (NP), A666-conjugated coumarin 6-labeled NP showed active targeting to OHCs. Furthermore, A666-coumarin 6-labeled NP could be significantly internalized by HEI-OC1 cells via the A666–prestin interaction. This facilitated the uptake of cells pretreated with A666-DEX-NP, followed by the cisplatin-treated group, which led to enhanced cell viability, reduced apoptotic properties, and decreased reactive oxygen species levels as compared to cells pretreated with DEX or DEX-NP, 4 hours in advance of cisplatin treatment. In cisplatin-treated guinea pigs, pretreatment with A666-DEX-NP effectively preserved OHCs and showed significant hearing protection at 4, 8, and 16 kHz as compared to pretreatment with saline, DEX, or DEX-NP formulation.Conclusion: This OHC-targeting DDS provides a novel strategy for DEX application that can be potentially used to combat cisplatin ototoxicity. Keywords: A666 peptide, dexamethasone, prestin, cisplatin ototoxicity

The chemotherapeutic agent cisplatin is renowned for its ototoxic effects. While hair cells in the cochlea are established targets of cisplatin, less is known regarding the afferent synapse, which is an essential component in the faithful temporal transmission of sound. The glutamate aspartate transporter (GLAST) shields the auditory synapse from excessive glutamate release, and its loss of function increases the vulnerability to noise, salicylate, and aminoglycosides. Until now, the involvement of GLAST in cisplatin‐mediated ototoxicity remains unknown. Here, we test in mice lacking GLAST the effects of a low‐dose cisplatin known not to cause any detectable change in hearing thresholds. When administered at nighttime, a mild hearing loss in GLAST KO mice was found but not at daytime, revealing a potential circadian regulation of the vulnerability to cisplatin‐mediated ototoxicity. We show that the auditory synapse of GLAST KO mice is more vulnerable to cisplatin administration during the active phase (nighttime) when compared to WT mice and treatment during the inactive phase (daytime). This effect was not related to the abundance of platinum compounds in the cochlea, rather cisplatin had a dose‐dependent impact on cochlear clock rhythms only after treatment at nighttime suggesting that cisplatin can modulate the molecular clock. Our findings suggest that the current protocols of cisplatin administration in humans during daytime may cause a yet undetectable damage to the auditory synapse, more so in already damaged ears, and severely impact auditory sensitivity in cancer survivors. [ABSTRACT FROM AUTHOR]

Abstract Cisplatin is a widely used chemotherapy drug, despite its significant ototoxic side effects. To date, the mechanism of cisplatin‐induced ototoxicity remains unclear, and hearing preservation during cisplatin‐based chemotherapy in patients is lacking. We found activation of the ATM‐Chk2‐p53 pathway to be a major determinant of cisplatin ototoxicity. However, prevention of cisplatin‐induced ototoxicity is hampered by opposite effects of ATM activation upon sensory hair cells: promoting both outer hair cell death and inner hair cell survival. Encouragingly, however, genetic or pharmacological ablation of p53 substantially attenuated cochlear cell apoptosis, thus preserving hearing. Importantly, systemic administration of a p53 inhibitor in mice bearing patient‐derived triple‐negative breast cancer protected auditory function, without compromising the anti‐tumor efficacy of cisplatin. Altogether, these findings highlight a novel and effective strategy for hearing protection in cisplatin‐based chemotherapy.

Objective: Effective management of patients diagnosed with ototoxicity is needed to reduce hearing and balance damage which affects communication and life quality. Despite widespread recommendations to monitor and manage ototoxicity in an early and effective manner, there is limited evidence to support the actual implementation of these recommendations for affected patient groups in healthcare services across the UK with limited publications available. In this study, an online questionnaire analysed the current practice of ototoxicity management and patient pathways across the UK once the diagnosis of ototoxicity was confirmed, targeting Audiologists, ENTs/AVPs and GPs. Design: Qualitative Survey Study. Study sample: A randomised sample of hearing services in the UK, including audiology departments; GP practices and local health settings were targeted with a total of 134 completed surveys. Results: About 72% reported the absence of ototoxicity management protocols within their centre. Results depicted great inconsistency and variation across the UK in ototoxicity management services provided, treatment modification, monitoring and referral pathways. Conclusion: Developing and advocating national guidelines are intended not only to inform clinical decision making but to provide minimum standards of care in ototoxicity management and offer greater awareness and education to improve patients' quality of life. [ABSTRACT FROM AUTHOR]

Cisplatin is a widely used chemotherapy drug, despite its significant ototoxic side effects. To date, the mechanism of cisplatin-induced ototoxicity remains unclear, and hearing preservation during cisplatin-based chemotherapy in patients is lacking. We found activation of the ATM-Chk2-p53 pathway to be a major determinant of cisplatin ototoxicity. However, prevention of cisplatin-induced ototoxicity is hampered by opposite effects of ATM activation upon sensory hair cells: promoting both outer hair cell death and inner hair cell survival. Encouragingly, however, genetic or pharmacological ablation of p53 substantially attenuated cochlear cell apoptosis, thus preserving hearing. Importantly, systemic administration of a p53 inhibitor in mice bearing patient-derived triple-negative breast cancer protected auditory function, without compromising the anti-tumor efficacy of cisplatin. Altogether, these findings highlight a novel and effective strategy for hearing protection in cisplatin-based chemotherapy. [ABSTRACT FROM AUTHOR]

• Concurrent mannitol transiently increased cisplatin concentration in the inner ear. • Cisplatin-induced ototoxicity was exacerbated with concurrent mannitol. • Delayed mannitol partially protects against cisplatin ototoxicity. • Delayed mannitol with antioxidants prevents cisplatin with mannitol ototoxicity. Cisplatin, a chemotherapeutic medication, remains in the cochlea indefinitely, causing permanent hearing loss. Mannitol, a diuretic medication, has been shown to increase the permeability of the blood labyrinth barrier (BLB). We hypothesize that mannitol increases the permeability of the BLB and therefore increases the rate of entry and egression of cisplatin and entry of otoprotective agents. Rats treated with cisplatin (t = 0) were given mannitol at either t = 0, t = 6 or t = 0,6 h. Another group of rats were treated with cisplatin with mannitol at 0 h and NAC/STS with and without mannitol at 6 h. Concurrent mannitol (t = 0) transiently increased cisplatin entry into the inner ear and exacerbated cisplatin-induced hearing loss. Delayed mannitol (t = 6) did not significantly increase cisplatin entry into the inner ear and preserved inner ear functionality and structure. Additional-delayed mannitol (t = 0,6) showed that the 2nd dose of mannitol prevented exacerbation of cisplatin with mannitol-induced hearing loss. A combination of delayed NAC/STS with mannitol (t = 6) was better than NAC/STS (t = 6) alone at providing partial to full protection against cisplatin with mannitol-induced hearing loss. In conclusion, mannitol injections at t = 6 h reduced cisplatin ototoxicity (instead of exacerbating cisplatin ototoxicity at t = 0 h), and it enhanced the otoprotective efficacy of antioxidants. This may provide an important therapeutic strategy to prevent cisplatin-induced hearing loss, a direct implication in protection against hearing loss in cisplatin chemotherapy. [ABSTRACT FROM AUTHOR]

• Hair cell mitochondrial activity increases shortly after cisplatin exposure. • Hair cell mitochondrial calcium levels increase shortly after cisplatin exposure. • Hair cell ROS production increases following cisplatin exposure. • Activated caspase-3 mediates cisplatin-induced hair cell death. • Disrupted mitochondrial bioenergetics may play key role in cisplatin ototoxicity. Cisplatin is a commonly used chemotherapeutic agent that causes debilitating high-frequency hearing loss. No targeted therapies currently exist to treat cisplatin ototoxicity, partly because the underlying mechanisms of cisplatin-induced hair cell damage are not completely defined. Zebrafish may offer key insights to cisplatin ototoxicity because their lateral-line organ contains hair cells that are remarkably similar to those within the cochlea but are optically accessible, permitting observation of cisplatin injury in live intact hair cells. In this study, we used a combination of genetically encoded biosensors in zebrafish larvae and fluorescent indicators to characterize changes in mitochondrial bioenergetics in response to cisplatin. Following exposure to cisplatin, confocal imaging of live intact neuromasts demonstrated increased mitochondrial activity. Staining with fixable fluorescent dyes that accumulate in active mitochondria similarly showed hyperpolarized mitochondrial membrane potential. Zebrafish expressing a calcium indicator within their hair cells revealed elevated levels of mitochondrial calcium immediately following completion of cisplatin treatment. A fluorescent ROS indicator demonstrated that these changes in mitochondrial function were associated with increased oxidative stress. After a period of recovery, cisplatin-exposed zebrafish demonstrated caspase-3-mediated apoptosis. Altogether, these findings suggest that cisplatin acutely disrupts mitochondrial bioenergetics and may play a key role in initiating cisplatin ototoxicity. [ABSTRACT FROM AUTHOR]

Highlights: [•] Rapamycin treatment improved hearing status in cisplatin challenged rats. [•] Rapamycin treatment decreased oxidative stress in cisplatin challenged rats. [•] Rapamycin treatment preserved hair cell damages in cisplatin challenged rats. [•] Rapamycin treatment promoted expression of autophagy related proteins LC3-II and Beclin-1. [•] We report that rapamycin treatment attenuated cisplatin-induced ototoxicity in rat models. [Copyright &y& Elsevier]

Abstract: Background: Cisplatin toxicity severely obstacles successful chemotherapy in lung cancer patients. Cisplatin uptake is considered as one of the major factors contributing to the side effects of cisplatin. Genetic variances of core genes also affect cisplatin toxicity. It has been identified that CTR1, copper transporter protein 1, plays an essential role in cisplatin uptake. The purpose of this study is to investigate whether CTR1 polymorphism is associated with platinum toxicity in non-small cell lung cancer (NSCLC) patients. Method: 204 incident NSCLC patients from three different institutions were enrolled and followed up. These patients were histologically confirmed with non-small cell lung cancer. All patients have accepted cisplatin-based chemotherapy for at least two cycles. Twenty SNPs of CTR1 were detected in these patients. Result: CTR1 rs10981694 A>C polymorphism is associated with cisplatin induced severe toxicity in NSCLC patients. C-carrier subjects presented poorer tolerance to ototoxicity (p <0.05). The survival times of patients with different rs10981694 genetic polymorphism were not significantly different. Conclusion: NSCLC patients carrying C allele of CTR1 rs10981694 presented more sensitivity to ototoxicity after cisplatin treatment. CTR1 plays an essential role in cisplatin toxicity and could be considered as a predictor for pretreatment evaluation in lung cancer patients. [Copyright &y& Elsevier]

Objective. To determine whether intratympanic (IT) dexamethasone ameliorates cisplatin-induced ototoxicity in a mouse model of presbycusis.Study Design. Controlled experimental study.Setting. Translational science experimental laboratory.Subjects and Methods. Auditory brainstem response (ABR) thresholds of 24-month-old CBA/J-NIA mice treated with cisplatin were compared 7 days after daily IT injections of dexamethasone (24 mg/mL) or saline.Results. Because of high (100%) mortality at 16 mg/kg, a single cisplatin dose of 14 mg/kg intraperitoneally was used. At this latter dose, pre-IT and post-IT treatment ABR thresholds were available in 13 of 16 mice. In IT saline–treated ears, cisplatin produced up to 9.5-dB ABR threshold elevations. In IT dexamethasone–treated ears, little protection against cisplatin was observed at 8 or 16 kHz where mean ABR thresholds were elevated. At 24 and 32 kHz, mean ABR threshold elevations were minimal at 0.6 to 1.4 dB. This protection was statistically significant (P ≤ .02).Conclusions. These results demonstrate, for the first time, a protective effect of a treatment against an ototoxic agent in the presence of age-related hearing loss. In the presence of age-related hearing loss, the protective effect of IT dexamethasone has a frequency gradient, being greatest in the high-frequency region of the cochlea. This latter finding contrasts with our previous report in young mice, in which the protective effect of IT dexamethasone was in the low-frequency region of the cochlea. [ABSTRACT FROM AUTHOR]

Introduction: Cisplatin (CDDP) is an effective and widely used chemotherapeutic agent for pediatric tumors, and ototoxicity is one of the dose-limiting side effects. Objective: It was the aim of our study to investigate the effect of acetyl L-carnitine (ALCAR) on experimental CDDP ototoxicity by audiologic tests, histomorphologic, immunohistochemical and ultrastructural examinations and to investigate the apoptotic pathways. Materials and Methods: Wistar albino rats (n = 28) were studied. Baseline audiological tests were performed in 4 groups: group 1, control; group 2, ALCAR; group 3, CDDP; group 4, CDDP + ALCAR-administered rats. Control audiological tests were performed on the 3rd day, and then the rats were sacrificed. Ear and brain specimens were examined by transmission electron microscopy, and caspase 3, 8 and 9 activities were investigated. Results: The CDDP-administered rats showed significant auditory brainstem response threshold shifts using all stimuli (clicks, 6-kHz and 8-kHz tone burst) compared with the control groups. The CDDP + ALCAR-administered rats showed significant auditory brainstem response threshold shifts by only click stimuli compared with the control groups. In the brain, spiral ganglion and organ of Corti, ultrastructural damage was prominent in group 3; the number of TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling)-positive cells and caspase 3, 8 and 9 immunostaining cells was significantly high in group 3. Conclusion: ALCAR improves CDDP-induced auditory impairment, and also antioxidative and antiapoptotic properties of ALCAR on CDDP ototoxicity were supported by the findings. Copyright © 2011 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Conclusion. Inductively coupled plasma mass spectrometry (ICP-MS) can be applied to organic tissues obtained from experimental animals. Hearing loss does not correlate with the platinum (Pt) concentration found in the inner ear. Drug structure and affinity to inner ear proteins could explain ototoxicity caused by cisplatin. Objectives. To analyse Pt affinity for brain and ear tissues (of similar embryologic origin) in the Wistar rat and clearance gradient after a single dose, and to correlate these findings with hearing changes. Materials and methods. Thirty-two Wistar rats were intraperitoneally injected with cisplatin at a dose of 5 mg/kg. Animals were sacrificed after obtaining auditory brain responses (ABRs) at 3, 7, 30 and 90 days (nine, seven, seven and nine animals, respectively). Brain and both temporal bones were extracted from each animal and analysed by ICP-MS to determine the absolute concentrations of the metal. Eight non-treated animals were employed as a control group. Results. The ABR thresholds were significantly elevated in animals from all groups after cisplatin treatment. A maximum accumulation of Pt for inner ear and brain was revealed around the first week: 3.175 (57%) and 0.342 (72%), respectively. Pt significantly accumulated in greater quantities in ear than in brain (p<0.01) and was cleared at a higher rate in brain than in ear (p<0.01) following cochlea/brain ratio analysis. No statistically significant correlation was found between amounts of Pt and hearing loss in the study animals. [ABSTRACT FROM AUTHOR]

Abstract: Cisplatin ototoxicity has at least three major targets in the cochlea: the stria vascularis, the organ of Corti, and the spiral ganglion. This study aims to differentiate between these three targets. In particular, we address the question of whether the effects at the level of the organ of Corti and spiral ganglion are mutually dependent or whether they develop in parallel. This question was approached by studying the ototoxic effects while they develop electrophysiologically and comparing these to earlier presented histological data [Van Ruijven et al., 2004. Hear. Res. 197, 44–54]. Guinea pigs were treated with intraperitoneal injections of cisplatin at a dose of 2mg/kg/day for either 4, 6, or 8 consecutive days. This time sequence has not revealed any evidence of one ototoxic process triggering another. Therefore, we have to stay with the conclusion of Van Ruijven et al. (2004) that both processes run in parallel. [Copyright &y& Elsevier]

Abstract: Cisplatin-induced ototoxicity is correlated with functional and morphological changes in the organ of Corti, the stria vascularis and the spiral ganglion. However, the cochlear sites of cisplatin uptake and accumulation have not been properly identified. Therefore, we have developed an immunohistochemical method to, indirectly, detect cisplatin in semithin cryosections of the guinea pig cochlea (basal turn) using an antiserum containing antibodies against cisplatin-DNA adducts. Platinated DNA was present in the nuclei of most cells in the organ of Corti and the lateral wall after cisplatin administration. Nuclear immunostaining was most pronounced in the outer hair cells, the marginal cells and the spiral ligament fibrocytes. This study is the first to demonstrate the presence of cisplatin in histological sections of the cochlea. [Copyright &y& Elsevier]

It has previously been demonstrated that ototoxicity induced by systemic administration of cisplatin is reduced by concomitant administration of melanocortins, like α-melanocyte stimulating hormone (α-MSH). However, these experiments were hampered by large interanimal variability. Therefore, we re-investigated the effects of systemically administered α-MSH during local (intracochlear) administration of cisplatin. Guinea pigs, implanted with a round-window electrode, allowing daily monitoring of the compound action potentials (CAPs), and a mini-osmotic pump, pumping either 0.5 μl/h physiological saline or cisplatin solution (15 μg/ml), were co-treated daily with a subcutaneous bolus injection of either α-MSH (75 μg/kg) or physiological saline for 1 week or until the electrocochleogram showed a persistent decrease in CAP amplitude (40 dB threshold shift at 8 kHz). Next, the animals were sacrificed and the cochleas were processed for histology. After 2–3 days, cisplatin alone caused a threshold shift at all frequencies (2–16 kHz). Co-administration with α-MSH consistently delayed the criterion threshold shift by 1 day. When the 40 dB criterion had been reached, similar outer hair cell losses in both the cisplatin/α-MSH- and cisplatin/saline-treated groups were observed. This experiment confirms that direct administration of cisplatin into the cochlea results in considerably less interanimal variability than systemic administration and that co-treatment with α-MSH delays cisplatin ototoxicity. Since cisplatin was delivered directly to the cochlea, the ameliorating effect of α-MSH probably involves a cochlear target. [Copyright &y& Elsevier]

Objective: To describe hearing changes in a group of 28 children (age range, 8-180 mo) undergoing protocol-based cisplatin therapy. Methods: Conventional, play audiometry, visual reinforcement audiometry (VRA), immittance audiometry, transient click evoked otoacoustic emissions (OAEs), and auditory brainstem response (ABR) evoked potentials were used to assess peripheral sensitivity and for threshold determination. Results: Bilateral symmetrical high-frequency sensorineural hearing loss was noted in 9 of the 28 children (26%). Hearing loss was evident as early as 1 month after chemotherapy and as late as 50 months and was not dependent on individual or cumulative dosage of cisplatin. Conclusions: 1) Presence of sensorineural hearing loss was independent of individual and/or cumulative dosage of cisplatin; 2) audiologic assessment should be incorporated into a child's periodic medical evaluations after chemotherapy treatment, as onset of sensorineural hearing loss cannot be predicted; 3) personal hearing aids may be indicated for those children with hearing loss affecting the low- to mid-frequencies; a personal assistive listening device (frequency modulated system) may be more appropriate for losses above 3000 Hz; and 4) evaluation and intervention by a speech-language pathologist may be indicated to address possible articulation or language development problems consequent to hearing loss. [ABSTRACT FROM AUTHOR]

Resveratrol is a non-flavonoid polyphenol compound that exists in many plants, and is considered an antitoxin. This study explores the effects from the regulation of miR-455-5p by resveratrol on cisplatin-induced ototoxicity via the PTEN-PI3K-AKT signaling pathway. For this, House Ear Institute-Organ of Corti 1 (HEI-OC1) cells were transfected with miR-455-5p inhibitor and treated with cisplatin and resveratrol, then cell proliferation, apoptosis, and oxidative stress were evaluated. A mouse model of hearing loss was established, and these mice were treated with cisplatin, resveratrol, or cisplatin combined with resveratrol, by intraperitoneal injection. The auditory brainstem response (ABR) threshold was measured, and hair cells were examined using immunofluorescence staining. The expression levels of miR-455-5p, PTEN, and PI3K/Akt proteins were examined. The results from our in-vitro experiments indicate that resveratrol promoted viability and reduced apoptosis and oxidative stress in cisplatin-induced HEI-OC1 cells. Resveratrol upregulated miR-455-5p, downregulated PTEN, and activated the PI3K-Akt axis. These effects of resveratrol were reversed by knock-down of miR-455-5p. The results from our in-vivo experiments indicate that resveratrol protected hearing and inhibited the hair-cell injury caused by cisplatin ototoxicity. Resveratrol also upregulated miR-455-5p, downregulated PTEN, and activated the PTEN-PI3K-Akt axis in cochlear tissues from cisplatin-treated mice. These results indicate that resveratrol upregulates miR-455-5p to target PTEN and activate the PI3K-Akt signaling pathway to counteract cisplatin ototoxicity.