Cisplatin-induced Cytotoxicity Research Articles

Hepato and nephroprotective activity of methanol extract of Hygrophila spinosa and its antibacterial potential against multidrug resistant Pandoraea sputorum

This research was aimed to evaluate the phytochemical profile, bactericidal activity of Hygrophila spinosa against multidrug resistant Pandoraea sputorum and assess their antioxidant competence against various radicals and studied their hepatoprotective and nephroprotective activity on HepG2 and HEK 293 cell line. The results showed that the methanol extract has various phytochemical components with reasonable quantity. Fortunately, the multidrug-resistant P. sputorum was sensitive (22.8 ± 0.2 mm of the zone of inhibition) at 15 mg mL−1 concentration of methanol extract. The higher concentration of phenolic and other phytochemical components, showed significant antioxidant activity against ferric, DPPH, hydroxyl, and ABTS radicals, with IC50 values of 71.09, 64.333, 91.157, and 104.931 g mL−1, respectively. Surprisingly, the methanol extract possesses hepato and nephroprotective activity against CCl4 and cisplatin-induced cytotoxicity on HepG2 and HEK 293 cell lines, respectively. It maintains the cell viability as up to 90.48% and 90.35% of HepG2 and EK 293 cell line at the concentration of 20 μg mL−1. The FTIR analysis states that the methanol extract possesses a significant functional group responsible for these multi-potential activities. These results suggest that, the methanol extract of H. spinosa might contain the most significant bioactive components with outstanding medicinal properties.

Pharmacogenomics of cisplatin-induced neurotoxicities: Hearing loss, tinnitus and peripheral sensory neuropathy.

12004 Background: Cisplatin is an essential component of first-line chemotherapy for many cancers, but causes neurotoxicity, including hearing loss (CisHL), tinnitus (CisTinn), and peripheral sensory neuropathy (CisPNeuro). However, few opportunities exist to identify risk factors and comorbidities for cisplatin-induced neurotoxicities among large numbers of homogenously treated patients without the confounding effect of cranial radiotherapy. Methods: Within a well-characterized clinical cohort of 1,680 cisplatin-treated testicular cancer survivors, linear and logistic regression analysis were utilized to analyze associations of CisHL (n = 1,258), CisTinn (n = 1,217), and CisPNeuro (n = 1,653) with non-genetic risk factors. Genome-wide association studies and gene-based analysis were performed on each phenotype. Results: Cisplatin-induced neurotoxicities (CisHL CisTinn, CisPNeuro), adjusting for age and cisplatin dose, were interdependent. Survivors with these neurotoxicities experienced more hypertension (CisTinn: OR = 2.62, p < 0.0001; CisHL: β = 0.25, p = 8.5 x10-4; CisPNeuro: OR = 1.86, p < 0.0001) and were more likely to report their health as poor (CisTinn: OR = 0.54, p < 0.0001; CisHL: β = -0.11, p < 0.0001; CisPNeuro: OR = 0.61, p < 0.0001). Persistent vertigo was significantly associated with both CisTinn (OR = 7.18, p < 0.0001) and CisPNeuro (OR = 4.29, p < 0.0001). In addition, CisTinn was significantly associated with hypercholesterolemia (OR = 1.78, p = 0.01). Importantly, gene-based association analyses identified significant associations between CisTinn and WNT8A (n = 1,037, p = 2.52x10-6) , encoding a signaling protein important in germ cell tumors; and marginal significance between CisHL and TXNRD1 (n = 1,071, p = 4.21x10-6) , thioredoxin reductase-1, which plays a key role in redox regulation. In silico analysis showed high expression levels of TXNRD1 were significantly correlated with cellular resistance to cisplatin in central nervous system tumor cells (Spearman Rho = 0.35, p = 0.04; R2= 0.14, p = 0.03), indicating TXNRD1 is protective for cisplatin-induced cytotoxicity. Previously, rs62283056 in WFS1 found to be significantly associated with CisHL (n = 511; subset of current population), was marginally significant in an independent replication cohort (p = 0.06; n = 606; subset of current population). Conclusions: Cisplatin-induced neurotoxicities are significantly associated with multiple clinical characteristics, including hypertension and self-reported poor health. WNT8A and TXNRD1 are notable risk factors for CisTinn and CisHL, respectively . Future studies should further investigate these genes and their potential impact on chemotherapy strategies. This study, based on the largest number of testicular cancer survivors investigated to date, highlights the clinical importance of these iatrogenic toxicities and their associated risk factors.

Mitophagy Impairment Aggravates Cisplatin-Induced Ototoxicity.

Cisplatin is an efficacious anticancer agent, but its use is limited by ototoxicity and resultant irreversible sensorineural hearing loss. Cisplatin ototoxicity is associated with cochlear cell oxidative stress and mitochondrial damage. However, mitophagy is vital for maintaining mitochondrial quality and cellular metabolism. Accordingly, we investigated the role of mitophagy in regulating cisplatin-induced ototoxicity using the auditory cell line HEI-OC1. In this study, HEI-OC1 cells were treated with either cisplatin alone (10 μM, 0, 8, 16, and 24 h); cisplatin (10 μM, 24 h) post transfection with small-interfering (si)RNAs targeting mitophagy-associated mRNAs; cisplatin (10 μM, 24 h) succeeding pretreatment with the mitophagy suppressor, 3-methyladenine (3-MA; 5 or 10 mM, 6 h); or cisplatin (30 μM, 24 h) following pretreatment with the mitophagy promoter, carbonyl cyanide m-chlorophenylhydrazone (CCCP; 1 or 2 μM, 2 h). The viability of cells, expression of mitophagy marker, and mitochondrial functions were then assessed in these cells. Cell viability was determined by a water-soluble tetrazolium assay; expression of mitophagy-associated proteins PINK1, Parkin, BNIP3, FUNDC1, p62, and LC3B was analyzed by Western blotting, mitochondrial membrane potential by flow cytometry, intracellular ATP by spectrophotometry, and mitochondrial degradation by dual staining for mitochondria and autophagosomes or lysosomes. Our results showed that cisplatin gradually reduced the viable cell number over time, induced mitochondrial depolarization, decreased intracellular ATP concentration, and enhanced the expression of PINK1, Parkin, BNIP3, p62, and LC3B. In addition, Parkin and BNIP3 knockdown accelerated cisplatin-induced loss of cell viability, mitochondrial membrane potential, mitophagosome/lysosome formation, and reduction in intracellular ATP production. Pretreatment with 3-MA aggravated the cisplatin-induced cytotoxicity, while that with CCCP reversed this effect. Overall, our findings indicate that mitophagy protects HEI-OC1 cells against cisplatin-induced cell death. Consequently, we strongly believe that targeted promotion of mitophagy may confer protection against cisplatin-induced ototoxicity.

Downregulation of ATM and BRCA1 Predicts Poor Outcome in Head and Neck Cancer: Implications for ATM-Targeted Therapy.

ATM and BRCA1 are DNA repair genes that play a central role in homologous recombination repair. Alterations of ATM and BRCA1 gene expression are found in cancers, some of which are correlated with treatment response and patient outcome. However, the role of ATM and BRCA1 gene expression in head and neck cancer (HNC) is not well characterized. Here, we examined the prognostic role of ATM and BRCA1 expression in two HNC cohorts with and without betel quid (BQ) exposure. The results showed that the expression of ATM and BRCA1 was downregulated in BQ-associated HNC, as the BQ ingredient arecoline could suppress the expression of both genes. Low expression of either ATM or BRCA1 was correlated with poor overall survival (OS) and was an independent prognostic factor in multivariate analysis (ATM HR: 1.895, p = 0.041; BRCA1 HR: 2.163, p = 0.040). The combination of ATM and BRCA1 expression states further improved on the prediction of OS (HR: 4.195, p = 0.001, both low vs. both high expression). Transcriptomic analysis showed that inhibition of ATM kinase by KU55933 induced apoptosis signaling and potentiated cisplatin-induced cytotoxicity. These data unveil poor prognosis in the HNC patient subgroup with low expression of ATM and BRCA1 and support the notion of ATM-targeted therapy.

Resistin increases cisplatin-induced cytotoxicity in lung adenocarcinoma A549 cells via a mitochondria-mediated pathway.

Lung cancer is the most commonly diagnosed cancer with a high mortality rate. Cisplatin is one of the most important chemotherapeutic agents for the treatment of lung cancer patients, especially in advanced stages. Recent studies show that cisplatin may interact with mitochondria to induce apoptosis,which may partly account for its cytotoxicity. In the study, we explored the effect of resistin on cisplatin-induced cytotoxicity in A549 cells and assessed whether mitochondria-dependent apoptosis was involved. Our results found that 25ng/ml resistin could significantly increase cisplatin-induced apoptosis and G2/M phase arrest, enhance reactive oxygen species generation, exacerbate the collapse of mitochondrial membrane potential, promote the distribution of cytochrome C in the cytoplasm from mitochondria, and activate caspase 3. Therefore, the results suggested that resistin might increase cisplatin-induced cytotoxicity via a mitochondria-mediated pathway in A549 cells. However, the precise mechanism remains to be explored in the future.

8-Alkylmercaptocaffeine derivatives: antioxidant, molecular docking, and in-vitro cytotoxicity studies

Due to their unique pharmacological characteristics, methylxanthines are known as therapeutic agents in a fascinating range of medicinal scopes. In this report, we aimed to examine some biological effects of previously synthesized 8-alkylmercaptocaffeine derivatives. Cytotoxic and antioxidative activity of 8-alkylmercaptocaffeine derivatives were measured in malignant A549, MCF7, and C152 cell lines. Assessment of cGMP levels and caspase-3 activity were carried out using a colorimetric competitive ELISA kit. Computational approaches were employed to discover the inhibitory mechanism of synthesized compounds. Among the twelve synthesized derivatives, three compounds (C1, C5, and C7) bearing propyl, heptyl, and 3-methyl-butyl moieties showed higher and more desirable cytotoxic activity against all the studied cell lines (IC50 < 100 µM). Furthermore, C5 synergistically enhanced cisplatin-induced cytotoxicity in MCF-7 cells (CI < 1). Both C5 and C7 significantly increased caspase-3 activity and intracellular cGMP levels at specific time intervals in all studied cell lines (P < 0.05). However, these derivatives did not elevate LDH leakage (P > 0.05) and exhibited no marked ameliorating effects on oxidative damage (P > 0.05). Computational studies showed that H-bond formation between the nitrogen atom in pyrazolo[4,3-D] pyrimidine moiety with Gln817 and creating a hydrophobic cavity result in the stability of the alkyl group in the PDE5A active site. We found that synthesized 8-alkylmercaptocaffeine derivatives induced cell death in different cancer cells through the cGMP pathway. These findings will help us to get a deeper insight into the role of methylxanthines as useful alternatives to conventional cancer therapeutics.

Borassus flabellifer L. crude male flower extracts alleviate cisplatin-induced oxidative stress in rat kidney cells

Objective: To investigate the effects of Borassus flabellifer L. extracts on antioxidant activity, maintenance of cellular redox, and mitochondrial function in cisplatin-induced kidney injury. Methods: The extracts of Borassus flabellifer were obtained from crude male flowers using ethyl acetate and methanol. The antioxidant potential was evaluated by 2,2-azino-bis-(3-ethylbenzothiazoline- 6-sulfonic acid), 2,2-diphenyl-1-picrylhydrazyl, and ferric reducing antioxidant power, and total phenolic content was also determined. Cytoprotective activity of ethyl acetate and methanolic extracts was assessed after kidney cells were treated with cisplatin. Oxidative stress was determined by glutathione (GSH) assay, and formation of reactive oxygen species (ROS) and changes in mitochondrial transmembrane potential (ΔΨm) using 2’,7’-dichlorofluorescin diacetate and JC-10 assays, respectively. Results: Borassus flabellifer methanolic extract exhibited greater antioxidant activity than the ethyl acetate extract. Cytoprotective effect was demonstrated in both extracts, particularly in the ethyl acetate extract. The extracts showed protection against the cytotoxic effect of cisplatin by prevention of the increased GSSG and declined GSH/GSSG ratio. Both extracts also prevented the increase in ROS formation, and loss of ΔΨm. Conclusions: Both Borassus flabellifer extracts show antioxidant activity and cytoprotective effect against cisplatin-induced cytotoxicity of NRK-52E cells by preventing oxidative stress and maintenance of GSH redox status. Borassus flabellifer extracts may possess beneficial effects on the prevention of oxidative stress- induced cell injury.

Protective role of herbal formulation-divine noni against cisplatin-induced cytotoxicity in healthy cells by activating Nrf2 expression: An in-vivo and in-vitro approach

BackgroundMorinda citrifolia (Noni) is an herbal remedy with multiple therapeutic properties such as antioxidant, anticancer, anti-inflammatory, antihypertensive effects due to rich in phytochemical constituents. PurposeTo evaluate chemoprotective effect of noni in dipping cisplatin (CP)-induced cytotoxicity in normal (healthy) cells through an antioxidant activity using in-vitro and in-vivo. MethodsChemoprotective study of fresh noni juice (NJ) and divine noni gold (DNG) at the doses (0.3125–10 mg/ml) were performed against CP (3.125–100 µM) induced cytotoxicity in normal cells (BEAS-2B) by Sulforhodamine B assay at 24 h and 48 h and the percentage of growth inhibition was calculated. Similarly, the protective effect of noni (360 mg/b.wt.) were investigated against CP (5 mg/ml) induced cardiotoxicity in healthy mice through the investigation of serum biochemical markers, endogenous antioxidant enzymes were interpreted. Finally, the chemoprotective mechanism of DNG was accomplished Nrf2 expression following CP challenged NIH-3T3 cells was performed by the western blot method. ResultsTreatment with noni at tested dose exhibited the least toxicity in normal cells (BEAS-2B). CP at the following concentrations induced cell death in time and dose-dependent manner. Whereas, noni revealed a significant cytoprotective effect against CP-induced cytotoxicity in the normal cells. Further in in-vivo study, treatment with noni at 360 mg/b.wt in CP injected animals attenuated cardiac injury as indicated by quenching the activities of serum biochemical markers, alleviated enzymatic and non-enzymatic antioxidant enzymes. Furthermore, noni attenuated CP induced toxicity by indirect antioxidant activity were proved by Nrf2 expression. ConclusionResults suggest that DNG is more potent than NJ. Findings confirmed that DNG protects against CP-induced toxicity by activating the Nrf2 expression. More studies are needed to comprehend the mechanisms of DNG cytoprotection.

Anticancer Efficacy and Mechanism of Amentoflavone for Sensitizing Oral Squamous Cell Carcinoma to Cisplatin.

Nuclear factor kappa B (NF-κB) inactivation and apoptosis activation have been shown to enhance the anticancer effect of cisplatin in oral squamous cell carcinoma (OSCC). Amentoflavone may suppress NF-κB activity and trigger apoptosis in different types of cancer. The aim of this study was to investigate the anticancer effect and mechanism of amentoflavone in combination with cisplatin in OSCC. We investigated the combination effect and mechanism of amentoflavone and cisplatin via cell viability analysis, flow cytometry-based apoptosis analyses, transwell migration/invasion assay, immunofluorescence staining and western blotting assay. Both amentoflavone and QNZ (NF-κB inhibitor) significantly increased cisplatin-induced cytotoxicity. Amentoflavone reduced cisplatin-triggered NF-κB activity and enhanced cisplatin-induced intrinsic caspase-dependent and independent apoptotic pathways. Moreover, amentoflavone augments cisplatin-suppressed invasion and migration ability of OSCC cells. Inactivation of NF-κB and induction of apoptosis through intrinsic caspase-dependent and independent apoptotic pathways are associated with amentoflavone enhanced anti-OSCC efficacy of cisplatin.

Germacrone Reduces Cisplatin-Induced Toxicity of Renal Proximal Tubular Cells via Inhibition of Organic Cation Transporter.

Cisplatin is a widely used chemotherapy for solid tumors; however, its benefits are limited by serious nephrotoxicity, particularly in proximal tubular cells. The present study investigated the renoprotective effect and mechanisms of germacrone, a bioactive terpenoid compound found in Curcuma species on cisplatin-induced toxicity of renal cells. Germacrone (50 and 100 µM) attenuated apoptosis of human renal proximal tubular cells, RPTEC/TERT1 following treatment with 50 µM cisplatin and for 48 h. Co-treating RPTEC/TERT1 cells with cisplatin and germacrone significantly reduced cellular platinum content compared with cisplatin treatment alone. The effect of germacrone on organic cation transporter 2 (OCT2) which is a transporter responsible for cisplatin uptake was determined. Germacrone showed an inhibitory effect on OCT2-mediated methyl-4-phenylpyridinium acetate (3H-MPP+) uptake with IC50 of 15 µM with less effect on OCT1. The germacrone's protective effect on cisplatin-induced cytotoxicity was not observed in cancer cells; cisplatin's anti-cancer activity was preserved. In conclusion, germacrone prevents cisplatin-induced toxicity in renal proximal tubular cells via inhibition OCT2 transport function and reducing cisplatin accumulation. Thus germacrone may be a good candidate agent used for reducing cisplatin-induced nephrotoxicity.

Ferrostatin-1 protects auditory hair cells from cisplatin-induced ototoxicity in vitro and in vivo

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.

Identifying the mechanisms underlying the protective effect of tetramethylpyrazine against cisplatin‑induced invitro ototoxicity in HEI‑OC1 auditory cells using gene expression profiling.

Sensorineural hearing loss is prevalent in patients receiving cisplatin therapy. Tetramethylpyrazine (Tet) and tanshinone IIA (Tan IIA) have protective roles against hearing impairment or ototoxicity. The present study aimed to investigate the molecular mechanisms underlying cisplatin-induced ototoxicity and the protective effect of Tet and Tan IIA against it. House Ear Institute-Organ of Corti 1 auditory cells were treated with titrating doses of Tan IIA, Tet, and cisplatin. In a cell viability assay, cisplatin, Tan IIA and Tet had IC50 values of 42.89 µM, 151.80 and 1.04×103 mg/l, respectively. Tan IIA augmented cisplatin-induced cytotoxicity. However, Tet concentrations <75 mg/l attenuated cisplatin-induced cytotoxicity and apoptosis. Moreover, RNA sequencing analysis was carried out on auditory cells treated for 30 h with 30 µM cisplatin alone for 48 h or combined with 37.5 mg/l Tet for 30 h. Differentially expressed genes (DEGs) induced in these conditions were identified and examined using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis. Cisplatin increased the expression of genes related to the p53 and FoxO pathways, such as Fas, p21/CDKN1A, and Bcl-2 binding component 3, but decreased the expression of insulin-like growth factor 1 (IGF1), as well as genes in the histone (Hist)1 and Hist2 clusters. Treatment with Tet downregulated FOXO3 and Bcl-2 binding component 3, and increased the expression of IGF1. Moreover, Tet upregulated genes associated with Wnt signaling, but not p53-related genes. Thus, the otoprotective properties of Tet might be mediated by activation of Wnt and IGF1 signaling, and inhibition of FoxO signaling.

Isodeoxyelephantopin Inactivates Thioredoxin Reductase 1 and Activates ROS-Mediated JNK Signaling Pathway to Exacerbate Cisplatin Effectiveness in Human Colon Cancer Cells.

Colon cancer is one of the leading causes of cancer-related death in the world. The development of new drugs and therapeutic strategies for patients with colon cancer are urgently needed. Isodeoxyelephantopin (ESI), a sesquiterpene lactone isolated from the medicinal plant Elephantopus scaber L., has been reported to exert antitumor effects on several cancer cells. However, the molecular mechanisms underlying the action of ESI is still elusive. In the present study, we found that ESI potently suppressed cell proliferation in human colon cancer cells. Furthermore, our results showed that ESI treatment markedly increased cellular reactive oxygen species (ROS) levels by inhibiting thioredoxin reductase 1 (TrxR1) activity, which leads to activation of the JNK signaling pathway and eventually cell death in HCT116 and RKO cells. Importantly, we found that ESI markedly enhanced cisplatin-induced cytotoxicity in HCT116 and RKO cells. Combination of ESI and cisplatin significantly increased the production of ROS, resulting in activation of the JNK signaling pathway in HCT116 and RKO cells. In vivo, we found that ESI combined with cisplatin significantly suppressed tumor growth in HCT116 xenograft models. Together, our study provide a preclinical proof-of-concept for ESI as a potential strategy for colon cancer treatment.

Platycodin D suppresses cisplatin-induced cytotoxicity by suppressing ROS-mediated oxidative damage, apoptosis, and inflammation in HEK-293 cells.

Cisplatin, a proven effective chemotherapeutic agent, has been used clinically to treat malignant solid tumors, whereas its clinical use is limited by serious side effect including nephrotoxicity. Platycodin D (PD), the major and marked saponin isolated from Platycodon grandiflorum, possesses many pharmacological effects. In this study, we evaluated its protective effect against cisplatin-induced human embryonic kidney 293 (HEK-293) cells injury and elucidated the related mechanisms. Our results showed that PD (0.25, 0.5, and 1 μM) can dose-dependently alleviate oxidative stress by decreasing malondialdehyde and reactive oxygen species, while increasing the levels of glutathione, superoxide dismutase, and catalase. Moreover, the elevation of apoptosis including Bax, Bad, cleaved caspase-3,-9, and decreased protein levels of Bcl-2, Bcl-XL induced by cisplatin were reversed after PD treatment. Importantly, PD pretreatment can also regulate PI3K/Akt and ERK/JNK/p38 signaling pathways. Furthermore, PD was found to reduce NF-κB-mediated inflammatory relative proteins. Our finding indicated that PD exerted significant effects on cisplatin induced oxidative stress, apoptosis and inflammatory, which will provide evidence for the development of PD to attenuate cisplatin-induced nephrotoxicity.

MAP30 protein from Momordica charantia is therapeutic and has synergic activity with cisplatin against ovarian cancer in vivo by altering metabolism and inducing ferroptosis

Increasing evidence shows that Traditional Chinese Medicine (TCM) has an obvious appeal for cancer treatment, but there is still a lack of scientific investigation of its underlying molecular mechanisms. Bitter melon or bitter gourd (Momordica charantia) is an edible fruit that is commonly consumed, and it is used to cure different diseases in various ancient folk medical practices. We report that a bioactive protein, MAP30, isolated from bitter melon seeds exhibited potent anticancer and anti-chemoresistant effects on ovarian cancer cells. Functional studies revealed that MAP30 inhibited cancer cell migration, cell invasion, and cell proliferation in various ovarian cancer cells but not normal immortalized ovarian epithelial cells. When administered with cisplatin, MAP30 produced a synergistic effect on cisplatin-induced cell cytotoxicity in ovarian cancer cells. When low doses of cisplatin and MAP30 were co-injected intraperitoneally, a remarkable reduction of tumor dissemination and tumor growth was observed in an ovarian cancer ascites mouse model. Notably, blood tests confirmed that MAP30 did not cause any adverse effects on liver and kidney functions in the treated mice. MAP30 activated AMP-activated protein kinase (AMPK) signaling via CaMKKβ and induced cell cycle arrest in the S-phase. MAP30 modulated cell metabolism of ovarian cancer cells via suppression of GLUT-1/-3-mediated glucose uptake, adipogenesis, and lipid droplet formation in tumor development and progression. MAP30 also induced an increase in intracellular Ca2+ ion concentration, which triggered ROS-mediated cancer cell death via apoptosis and ferroptosis. Collectively, these findings suggest that natural MAP30 is a non-toxic supplement that may enhance chemotherapeutic outcomes and benefit ovarian cancer patients with peritoneal metastases.

Abstract 5039: SCD1/FADS2 and ferroptosis signalings orchestrate ovarian cancer cell metabolism and metastatic progression in peritoneal metastases

Abstract Peritoneal metastases are common and usually associated with poor prognosis in advanced ovarian cancers. Emerging evidence indicates that the ascites microenvironment provides a key reservoir of growth factors and free fatty acids for promoting metastatic recurrence and chemoresistance of ovarian cancers. However, how the metastatic ovarian cancer cells adapt and utilize such a unique tumor microenvironment remains elusive. Here, we report that ovarian cancer cells co-cultured in ascites or omental conditioned medium (OCM) enhance their oncogenic capacities through elevated lipid metabolism. RNA sequencing (RNA-seq) and lipidomic profiling analyses revealed two key mediators of UFAs, Stearoyl-CoA Desaturase-1 (SCD1) and Fatty acid Desaturase-2 (FADS2) were upregulated accompanied with the accumulation of poly- and mono-unsaturated fatty acids (UFAs) in ovarian cancer cells co-cultured in OCM. Enforced expression of either SCD1 or FADS2 promotes cancer stemness, in vitro and ex vivo tumor colony formation, and cell migration/invasion through activation of NFκB signaling. SCD1/FADS2 increases not only UFAs accumulation but also the cell membrane fluidity which is crucial for the epithelial-mesenchymal transition (EMT) and metastatic potentials. On the other hand, RNA-Seq analysis on SCD1/FADS2-depleted ovarian cancer cells showed the ferroptotic activities were inversely correlated with SCD1/FADS2. Of note, either knockout of SCD1/FADS2 or co-treatment of Erastin could enhance cisplatin-induced cytotoxicity through the elevation of iron-mediated reactive oxygen species (ROS), and subsequently led ferroptosis by upregulation of GPX4/xCT expressions in ovarian cancer cells. Higher tumorigenic capacity expressed in iron-rich ovarian cancer cells, which contains sphere formation, EMT potential and cell viability. Taken together, SCD1/FADS2 and ferroptosis signaling pathways orchestrate the metabolic activities, ROS stresses and cellular iron homeostasis during the metastatic progression of ovarian cancer cells in peritoneum microenvironment. Hence, targeting these signaling cascades by the drug cocktail/combination strategy could reduce the risk of metastatic recurrence and chemoresistance in advanced ovarian cancers. Citation Format: Yang Xuan, Mingo MH Yung, Arvin FS Chen, Hextan YS Ngan, David W Chan. SCD1/FADS2 and ferroptosis signalings orchestrate ovarian cancer cell metabolism and metastatic progression in peritoneal metastases [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5039.

α-Mangostin, a Dietary Xanthone, Exerts Protective Effects on Cisplatin-Induced Renal Injury via PI3K/Akt and JNK Signaling Pathways in HEK293 Cells

Previous report has confirmed the beneficial effects of α-mangostin (α-MG), a major and representative xanthone distributed in mangosteen (Garcinia mangostana) on the cisplatin-induced rat model. However, the molecular mechanisms related to its renoprotection have not been elucidated exhaustively. The present study investigated the protective effect of α-MG against cisplatin-induced cytotoxicity in the human embryonic kidney (HEK293) cell model. In this study, α-MG prevented cisplatin-induced cell death, accompanied with the decreased levels of malondialdehyde and increased glutathione content. Particularly, α-MG significantly suppressed the overproduction of reactive oxygen species (ROS), restored the activation of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt), and downregulated the c-JUN N-terminal kinase (JNK) pathways following cisplatin challenge. Subsequently, the cleavage of caspases and poly-ADP-ribose polymerase (PARP) implicating ROS-mediated apoptosis pathways induced by cisplatin was effectively inhibited by α-MG. In conclusion, our findings provided a rationale for the development of α-MG to attenuate cisplatin-induced nephrotoxicity.

Protective Effects of Glucose-Related Protein 78 and 94 on Cisplatin-Mediated Ototoxicity.

Cisplatin is a widely used chemotherapeutic drug for treating various solid tumors. Ototoxicity is a major dose-limiting side effect of cisplatin, which causes progressive and irreversible sensorineural hearing loss. Here, we examined the protective effects of glucose-related protein (GRP) 78 and 94, also identified as endoplasmic reticulum (ER) chaperone proteins, on cisplatin-induced ototoxicity. Treating murine auditory cells (HEI-OC1) with 25 μM cisplatin for 24 h increased cell death resulting from excessive intracellular reactive oxygen species (ROS) accumulation and caspase-involved apoptotic signaling pathway activation with subsequent DNA fragmentation. GRP78 and GRP94 expression was increased in cells treated with 3 nM thapsigargin or 0.1 μg/mL tunicamycin for 24 h, referred to as mild ER stress condition. This condition, prior to cisplatin exposure, attenuated cisplatin-induced ototoxicity. The involvement of GRP78 and GRP94 induction was demonstrated by the knockdown of GRP78 or GRP94 expression using small interfering RNAs, which abolished the protective effect of mild ER stress condition on cisplatin-induced cytotoxicity. These results indicated that GRP78 and GRP94 induction plays a protective role in remediating cisplatin-ototoxicity.

MiR-140 Resensitizes Cisplatin-Resistant NSCLC Cells to Cisplatin Treatment Through the SIRT1/ROS/JNK Pathway.

BackgroundAlthough cisplatin is an effective chemotherapeutic drug that is commonly used for non-small-cell lung cancer (NSCLC) treatment, the drug resistance usually occurs during the long-term use of it. It is urgent to develop strategies to reduce the resistance of NSCLC cells to cisplatin.MethodsCisplatin-resistant NSCLC cell lines (PC9/R and A549/R) were acquired through long-term exposure of PC9 and A549 cells to cisplatin. QRT-PCR analysis was performed to compare the expression of miR-140 between routine NSCLC cells and cisplatin-resistant NSCLC cells. CCK-8 assay was used to evaluate the effect of miR-140 on the sensitivity of PC9/R and A549/R to cisplatin. Western blot assay and luciferase reporter assay were used to confirm the regulation of miR-140 on SIRT1. Western blot and flow cytometry analysis were performed to evaluate the effect of miR-140 on the apoptosis pathway induced by cisplatin.ResultsPC9/R and A549/R exhibited obviously lower sensitivity compared to their parental PC9 and A549 cells, respectively. Furthermore, PC9/R and A549/R cells expressed significantly lower levels of miR-140 compared to their parental PC9 and A549 cells, respectively. However, transfection with miR-140 mimics significantly resensitized the PC9/R and A549/R to cisplatin-induced cytotoxicity. In the mechanism research, we confirmed that SIRT1 was overexpressed and was targeted by miR-140 in PC9/R and A549/R. Furthermore, overexpression of SIRT1 was responsible for the resistance to cisplatin in PC9/R and A549/R cells. Transfection with miR-140 was able to inhibit the expression of SIRT1 and thus inhibited the SIRT1/ROS/JNK pathway. As a result, the PC9/R and A549/R cells restored the sensitivity to cisplatin-induced apoptosis.ConclusionMiR-140 resensitizes cisplatin-resistant NSCLC cells to cisplatin treatment through the SIRT1/ROS/JNK pathway.

The Effect of Adipose Derived Stem Cells versus Platelet Rich Plasma in Ameliorating Cisplatin-Induced Injury on The Submandibular Salivary Gland.”A Comparative Histological Study”.

Background: Cisplatin is a potent anti-carcinogenic agent; however, it has many dose-limiting side effects. The aim of our study was to determine and compare the effectiveness of adipose-derived stem cells (ADSCs) and platelet rich plasma (PRP) as a treatment modality against cisplatin-induced cytotoxicity in the submandibular glands of Albino rats.Methods: Thirty-eight adult male albino rats, were used in the present study. Ten rats were used as a source of PRP, and the rest were included in the experimental design as follows: negative control group, cisplatin group (positive control) received (5mg/kg/week) cisplatin intraperitoneal on day 1 and 8. ADSCs group received ADSCs (2 × 10˄6 cells/rat) once intravenous via tail vein + cisplatin. PRP group received PRP (0.5 mL/kg by intraperitoneal injection 3times/week) + cisplatin.Results: Both ADSCs and PRP enhanced the regeneration of submandibular salivary gland tissue after the cisplatin induced cytotoxicity; represented by significant increase in area fraction of acini, percentage of hemolysis as well as significant decrease in area fraction of apoptotic cells in both groups compared to cisplatin group respectively. There was no significant difference between both groups regarding all comparative parameters used in this study. In addition, there was a non-significant difference in the area fraction of apoptotic cells between PRP group and the control group, but we detected a significant difference between ADSCs group and the control group regarding the same parameter.Conclusions: Both adipose-derived stem cells and Platelet rich plasma are considered as effective treatment for cisplatin-induced cytotoxicity in submandibular salivary glands. However, PRP is recommended over ADSCs as a potent and effective treatment due to its safety, easy accessibility and proved treatment effect.