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Saito S, Koya Y, Kajiyama H, Yamashita M, Nawa A. Indoxyl Sulfate Promotes Metastatic Characteristics of Ovarian Cancer Cells via Aryl Hydrocarbon Receptor-Mediated Downregulation of the Mas Receptor. J Transl Med 2023; 103:100025. [PMID: 36925201 DOI: 10.1016/j.labinv.2022.100025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 10/12/2022] [Accepted: 10/28/2022] [Indexed: 01/11/2023] Open
Abstract
Although platinum-combination chemotherapy shows a high response rate at the primary site, epithelial ovarian cancer (EOC) treatment remains challenging because of tumor recurrence and metastasis. Recent studies have revealed that chemotherapy paradoxically promotes cancer cell survival, proliferation, and metastasis, although the reason for this remains unclear. The underlying molecular mechanisms that contribute to chemotherapy-induced metastasis need to be elucidated to establish effective therapeutic strategies. Acute kidney injury is a known side effect of cisplatin treatment, and kidney dysfunction results in the accumulation of uremic toxins in the serum. The present study aimed to investigate whether indoxyl sulfate (IS), a representative uremic toxin, affects the pathophysiology of EOC. In this study, IS reduced the expression of Mas receptor (MasR) in cultured human EOC cells. Both knockdown of the aryl hydrocarbon receptor (AhR), which is an intracellular IS receptor, and inhibition of AhR function suppressed IS-mediated downregulation of MasR in SK-OV-3 cells. IS induced the phosphorylation of signal transducer and activator of transcription 3 (STAT3) in an AhR-dependent manner. Inhibition of the STAT3 pathway or reactive oxygen species production suppressed the IS-mediated reduction of MasR. IS stimulated cell migration and invasion of SK-OV-3 cells in an AhR-dependent manner. Cisplatin-nephropathy model mice exhibited elevated levels of serum IS accompanied by elevated levels of blood urea nitrogen and serum creatinine. Furthermore, intraperitoneal administration of IS in mice promoted tumor growth and metastasis. Finally, we found that the MasR agonist Ang-(1-7) suppressed the IS-mediated effects on cell proliferation, migration, and invasion of SK-OV-3 cells. However, the knockdown of MasR expression by specific small interfering RNA in the absence of IS resulted in only minimal promotion of cell migration and invasion. These findings demonstrate that IS promotes malignancy in ovarian cancer via AhR-mediated downregulation of MasR function, whereas Ang-(1-7) attenuates this effect, thereby suggesting that Ang-(1-7) could provide a future treatment strategy for this cancer type.
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Affiliation(s)
- Shinichi Saito
- Bell Research Center, Department of Obstetrics and Gynecology Collaborative Research, Nagoya University Graduate School of Medicine, Tsurumai-cho, Showa-ku, Nagoya, Japan; Bell Research Center for Reproductive Health and Cancer, Medical Corporation Kishokai, Nagoya, Aichi, Japan.
| | - Yoshihiro Koya
- Bell Research Center, Department of Obstetrics and Gynecology Collaborative Research, Nagoya University Graduate School of Medicine, Tsurumai-cho, Showa-ku, Nagoya, Japan; Bell Research Center for Reproductive Health and Cancer, Medical Corporation Kishokai, Nagoya, Aichi, Japan
| | - Hiroaki Kajiyama
- Department of Obstetrics and Gynecology, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya, Japan
| | - Mamoru Yamashita
- Bell Research Center for Reproductive Health and Cancer, Medical Corporation Kishokai, Nagoya, Aichi, Japan
| | - Akihiro Nawa
- Bell Research Center, Department of Obstetrics and Gynecology Collaborative Research, Nagoya University Graduate School of Medicine, Tsurumai-cho, Showa-ku, Nagoya, Japan; Bell Research Center for Reproductive Health and Cancer, Medical Corporation Kishokai, Nagoya, Aichi, Japan
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Shahid F, Farooqui Z, Khan F. Cisplatin-induced gastrointestinal toxicity: An update on possible mechanisms and on available gastroprotective strategies. Eur J Pharmacol 2018. [PMID: 29530589 DOI: 10.1016/j.ejphar.2018.03.009] [Citation(s) in RCA: 104] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Cisplatin (cis-diamminedichloroplatinum [II], CP) is most widely prescribed in chemotherapy and efficaciously treats diverse human cancers, with remission rates > 90% in testicular cancers. However, clinical use of CP is associated with numerous untoward side effects, in particular, at the gastrointestinal level that reduces the therapeutic efficacy of CP and often results in withdrawal of its clinical usage in long term cancer chemotherapy. Substantial strides have been made to identify effective protective strategies against CP-induced nephrotoxicity, hepatotoxicity and ototoxicity. Unfortunately, very limited studies have focused on CP-induced gastrointestinal toxicity and advances in developing potent gastroprotective strategies/agents are still lacking. The current article reviews the metabolism and pharmacokinetics of CP, mechanisms underlying CP-induced gastrointestinal toxicity and lastly displays the potential approaches including plant-derived agents (phytochemicals) utilized to counteract CP-induced gastrointestinal dysfunction. Furthermore, the gastroprotective agents described in the experimental literature have shown partial protection against CP-induced intestinal damage. This stresses the need to ascertain new information on the underlying mechanism and to discover novel combinatorial strategies for the abrogation of CP-induced gastrointestinal toxicity.
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Affiliation(s)
- Faaiza Shahid
- Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, U.P., India
| | - Zeba Farooqui
- Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, U.P., India
| | - Farah Khan
- Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, U.P., India.
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Chen MC, Hsu WL, Hwang PA, Chen YL, Chou TC. Combined administration of fucoidan ameliorates tumor and chemotherapy-induced skeletal muscle atrophy in bladder cancer-bearing mice. Oncotarget 2018; 7:51608-51618. [PMID: 27323407 PMCID: PMC5239500 DOI: 10.18632/oncotarget.9958] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Accepted: 05/17/2016] [Indexed: 01/06/2023] Open
Abstract
Cancer cachexia is characterized by anorexia, skeletal muscle atrophy, and systemic inflammation. Fucoidan extracted from brown algae exhibits anti-inflammatory and anticancer activities. However, whether fucoidan ameliorates tumour and chemotherapy-induced muscle atrophy and -related cachectic symptoms remains unknown. Compared with mice with bladder cancer treated with chemotherapy alone (TGC group), those treated with a combination of low molecular weight fucoidan (LMWF) and chemotherapy drugs such as gemcitabine and cisplatin (TGCF) showed a significant reduction of body weight loss, muscle atrophy, and intestinal injury and dysfunction. Moreover, myostatin, activin A, and pro-inflammatory cytokine production, FoxO3 expression and activation, NF-κB activation, MuRF-1 and MAFbx/atrogin-1 expression, and proteasome activity in muscle were significantly decreased in the TGCF group compared with the TGC group. In addition, insulin-like growth factor 1 (IGF-1) expression and formation, and IGF-1-regulated mTOR/p70S6k/4EBP-1 protein synthesis signalling were elevated in the TGCF group compared with the TGC group. Taken together, these results suggest that LMWF is a potential agent for preventing cancer cachexia-associated muscle atrophy during chemotherapy. Furthermore, the beneficial effect of LMWF may be attributed to suppressing NF-κB-evoked inflammation, myostatin and activin A production, and subsequent muscle proteolysis, and enhancing IGF-1-dependent protein synthesis.
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Affiliation(s)
- Meng-Chuan Chen
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan
| | - Wen-Lin Hsu
- School of Medicine, Tzu Chi University, Hualien, Taiwan.,Department of Radiation Oncology, Buddhist Tzu Chi General Hospital, Hualien, Taiwan
| | - Pa-An Hwang
- Department of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, Taiwan
| | - Yen-Lin Chen
- Department of Pathology, Cardinal Tien Hospital, School of Medicine, Fu-Jen Catholic University, New Taipei City, Taiwan
| | - Tz-Chong Chou
- Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan.,Department of Biotechnology, Asia University, Taichung, Taiwan.,China Medical University Hospital, China Medical University, Taichung, Taiwan
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Shahid F, Farooqui Z, Khan AA, Khan F. Oral Nigella sativa oil and thymoquinone administration ameliorates the effect of long-term cisplatin treatment on the enzymes of carbohydrate metabolism, brush border membrane, and antioxidant defense in rat intestine. Naunyn Schmiedebergs Arch Pharmacol 2018; 391:145-157. [PMID: 29302711 DOI: 10.1007/s00210-017-1444-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2017] [Accepted: 11/27/2017] [Indexed: 12/22/2022]
Abstract
We have previously shown that oral administration of Nigella sativa oil (NSO) ameliorates the deleterious gastrointestinal effects of cisplatin (CP), administered as a single dose. Since a typical clinical CP dosing regimen involves multiple cycles of CP administration in lower doses, in the present study we investigate the protective efficacy of NSO and its major bioactive constituent, thymoquinone (TQ), against multiple-dose CP treatment-induced deleterious biochemical and histological changes in rat intestine. Rats were divided into six groups, viz., control, CP, CP+NSO, CP+TQ, NSO, and TQ. Animals in CP+NSO and CP+TQ groups were pre-administered NSO (2 ml/kg bwt, orally) and TQ (1.5 mg/kg bwt, orally), respectively, daily for 14 days and were then treated with five repeated doses of CP (3 mg/kg bwt, i.p.), every fourth day for 20 days while still receiving NSO/TQ. CP treatment alone led to a significant decline in specific activities of brush border membrane (BBM) enzymes while NSO or TQ administration to CP-treated rats significantly prevented the decline in BBM enzyme activities in the isolated brush border membrane vesicles (BBMV) as well as in mucosal homogenates. Furthermore, both NSO and TQ administration markedly ameliorated CP-induced alterations on carbohydrate metabolism enzymes and the enzymatic and non-enzymatic parameters of antioxidant defense system in the intestinal mucosa. However, NSO appeared to be more efficacious than TQ in protecting against CP-induced gastrointestinal dysfunction. Histopathological findings corroborated the biochemical results. Thus, NSO and TQ may prove clinically useful in amelioration of the intestinal toxicity associated with long-term CP chemotherapy.
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Affiliation(s)
- Faaiza Shahid
- Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, U.P., 202002, India
| | - Zeba Farooqui
- Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, U.P., 202002, India
| | - Aijaz Ahmed Khan
- Department of Anatomy, Faculty of Medicine, J. N. Medical College, Aligarh Muslim University, Aligarh, U.P., 202002, India
| | - Farah Khan
- Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, U.P., 202002, India.
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Shahid F, Farooqui Z, Abidi S, Parwez I, Khan F. Oral administration of thymoquinone mitigates the effect of cisplatin on brush border membrane enzymes, energy metabolism and antioxidant system in rat intestine. Biomed Pharmacother 2017; 94:1111-1120. [PMID: 28821162 DOI: 10.1016/j.biopha.2017.08.044] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2017] [Revised: 08/07/2017] [Accepted: 08/07/2017] [Indexed: 12/26/2022] Open
Abstract
Cisplatin (CP) is a widely used chemotherapeutic agent that elicits severe gastrointestinal toxicity. Nigella sativa, a member of family Ranunculaceae, is one of the most revered medicinal plant known for its numerous health benefits. Thymoquinone (TQ), a major bioactive component derived from the volatile oil of Nigella sativa seeds, has been shown to improve gastrointestinal functions in animal models of acute gastric/intestinal injury. In view of this, the aim of the present study was to investigate the protective effect of TQ on CP induced toxicity in rat intestine and to elucidate the mechanism underlying these effects. Rats were divided into four groups viz. control, CP, TQ and CP+TQ. Animals in CP+TQ and TQ groups were orally administered TQ (1.5mg/kg bwt) with and without a single intraperitoneal dose of CP (6mg/kg bwt) respectively. The effect of TQ was determined on CP induced alterations in the activities of brush border membrane (BBM), carbohydrate metabolism, and antioxidant defense enzymes in rat intestine. TQ administration significantly mitigated CP induced decline in the specific activities of BBM marker enzymes, both in the mucosal homogenates and in the BBM vesicles (BBMV) prepared from intestinal mucosa. Furthermore, TQ administration restored the redox and metabolic status of intestinal mucosal tissue in CP treated rats. The biochemical results were supported by histopathological findings that showed extensive damage to intestine in CP treated rats and markedly preserved intestinal histoarchitecture in CP and TQ co-treated group. The biochemical and histological data suggest a protective effect of TQ against CP-induced gastrointestinal damage. Thus, TQ may have a potential for clinical application to counteract the accompanying gastrointestinal toxicity in CP chemotherapy.
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Affiliation(s)
- Faaiza Shahid
- Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, U.P., India
| | - Zeba Farooqui
- Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, U.P., India
| | - Subuhi Abidi
- Department of Zoology, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, U.P., India
| | - Iqbal Parwez
- Department of Zoology, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, U.P., India
| | - Farah Khan
- Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, U.P., India.
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Intestinal toxicity evaluation of long-circulating and pH-sensitive liposomes loaded with cisplatin. Eur J Pharm Sci 2017; 106:142-151. [DOI: 10.1016/j.ejps.2017.05.046] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Revised: 05/19/2017] [Accepted: 05/20/2017] [Indexed: 12/20/2022]
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Shahid F, Farooqui Z, Rizwan S, Abidi S, Parwez I, Khan F. Oral administration of Nigella sativa oil ameliorates the effect of cisplatin on brush border membrane enzymes, carbohydrate metabolism and antioxidant system in rat intestine. ACTA ACUST UNITED AC 2017; 69:299-306. [PMID: 28215571 DOI: 10.1016/j.etp.2017.02.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 01/30/2017] [Accepted: 02/07/2017] [Indexed: 12/25/2022]
Abstract
Cisplatin (CP) is an effective chemotherapeutic agent that induces gastrointestinal toxicity. Nigella sativa oil (NSO) has been shown to be beneficial in a wide range of gastrointestinal disorders. The present study investigates the possible protective effect of NSO on CP-induced gastrointestinal toxicity. NSO administration (2ml/kg bwt, orally), prior to and following, a single dose CP treatment (6mg/kg bwt. ip), significantly attenuated the CP-induced decrease in brush border membrane (BBM) enzyme activities in intestinal homogenates and BBM vesicles (BBMV). NSO administration also mitigated CP induced alterations in the activities of carbohydrate metabolism enzymes and in the enzymatic and non-enzymatic antioxidant parameters in the intestine. The results suggest that NSO by empowering the endogenous antioxidant system improves intestinal redox and metabolic status and restores BBM integrity in CP treated rats. Histopathological studies supported the biochemical findings. Thus, NSO may help prevent the accompanying gastrointestinal dysfunction in CP chemotherapy.
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Affiliation(s)
- Faaiza Shahid
- Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, U.P., India
| | - Zeba Farooqui
- Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, U.P., India
| | - Sana Rizwan
- Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, U.P., India
| | - Subuhi Abidi
- Department of Zoology, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, U.P., India
| | - Iqbal Parwez
- Department of Zoology, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, U.P., India
| | - Farah Khan
- Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, U.P., India.
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Arivarasu N, Priyamvada S, Mahmood R. Oral administration of caffeic acid ameliorates the effect of cisplatin on brush border membrane enzymes and antioxidant system in rat intestine. ACTA ACUST UNITED AC 2013; 65:21-5. [DOI: 10.1016/j.etp.2011.05.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Accepted: 05/04/2011] [Indexed: 12/23/2022]
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Naqshbandi A, Rizwan S, Khan MW, Khan F. Dietary flaxseed oil supplementation ameliorates the effect of cisplatin on brush border membrane enzymes and antioxidant system in rat intestine. Hum Exp Toxicol 2012; 32:385-94. [PMID: 22751286 DOI: 10.1177/0960327112438929] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Cisplatin (CP; cis-diamminedichloroplatinum II) is a drug widely used against different types of solid tumors. Patients receiving CP, however, experience very profound and long lasting gastrointestinal symptoms. Recently, ω-3 polyunsaturated fatty acid-enriched flaxseed/flaxseed oil (FXO) has shown numerous health benefits. The present study was undertaken to investigate whether FXO can prevent CP-induced adverse biochemical changes in the small intestine of rats. A single intraperitoneal dose of CP (6 mg/kg body weight) was administered to male Wistar rats fed with control diet (CP group) and FXO diet (CPFXO group). Administration of CP led to a significant decline in the specific activities of brush border membrane enzymes both in the mucosal homogenates and in the isolated membrane vesicles. Lipid peroxidation and total sulfhydryl groups were altered upon CP treatment, indicating the generation of oxidative stress. The activities of SOD, catalase and glutathione peroxidase also decreased in CP-treated rats. In contrast, dietary supplementation of FXO prior to and following CP treatment significantly attenuated the CP-induced changes in all these parameters. FXO feeding markedly enhanced resistance to CP-elicited adverse gastrointestinal effects. The results suggest that FXO owing to its intrinsic biochemical/antioxidant properties is an effective agent in reducing the adverse effects of CP on intestine.
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Affiliation(s)
- A Naqshbandi
- Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, Uttar Pradesh, India
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Bodiga VL, Bodiga S, Surampudi S, Boindala S, Putcha U, Nagalla B, Subramaniam K, Manchala R. Effect of vitamin supplementation on cisplatin-induced intestinal epithelial cell apoptosis in Wistar/NIN rats. Nutrition 2011; 28:572-80. [PMID: 22189195 DOI: 10.1016/j.nut.2011.09.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Revised: 08/17/2011] [Accepted: 09/07/2011] [Indexed: 12/18/2022]
Abstract
OBJECTIVE Chemotherapeutic agents induce small intestinal mucositis that is characterized structurally by crypt loss and villus atrophy and functionally by absorptive and barrier impairments. We studied the effect of selected individual vitamins and multiple-vitamin mixture supplementation in modulating cisplatin-induced intestinal damage and apoptosis. METHODS Thirty-six male Wistar/NIN rats 20 wk old and fed the control diet (AIN-93G) were randomly divided into six groups. Five groups were administered cisplatin (2.61 mg/kg of body weight) once a week for 3 wk and were concomitantly provided the control diet or riboflavin, folate, α- tocopherol, or a multiple-vitamin mixture supplemented diet. The sixth group served as a control for cisplatin and received saline as the vehicle. Intestinal epithelial cell apoptosis was monitored by morphometry, M30 staining, DNA fragmentation, and caspase-3 activity. Functional and structural integrities were determined by measuring activities of alkaline phosphatase and lysine ala-dipeptidyl aminopeptidase and the villus height/crypt depth ratio. Oxidative burden was assessed as the formation of thiobarbituric acid-reactive substances and protein carbonyls. Plasma levels of selected vitamins were also measured. RESULTS Cisplatin administration significantly increased intestinal apoptosis in the villus and crypt regions that correlated with increased oxidative damage, decreased Bcl-2/Bax, and compromised functional integrity. Riboflavin, folate, and the multiple-vitamin mixture supplementation attenuated the cisplatin-induced increase in apoptotic indices, with a decrease in oxidative burden, increased Bcl-2/Bax, and improved functional and structural integrities. The α-tocopherol supplementation, although effective in attenuating oxidative stress and improving functional integrity, failed to lower the apoptotic indices. CONCLUSIONS Riboflavin, folate, and the multiple-vitamin supplementation proved to be more efficacious in attenuating the cisplatin-induced intestinal damage and associated changes in apoptosis.
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Affiliation(s)
- Vijaya Lakshmi Bodiga
- Pathology Division, National Institute of Nutrition, Hyderabad, Andhra Pradesh, India.
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JS-K, a nitric oxide prodrug, has enhanced cytotoxicity in colon cancer cells with knockdown of thioredoxin reductase 1. PLoS One 2010; 5:e8786. [PMID: 20098717 PMCID: PMC2808390 DOI: 10.1371/journal.pone.0008786] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2009] [Accepted: 12/30/2009] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND The selenoenzyme thioredoxin reductase 1 has a complex role relating to cell growth. It is induced as a component of the cellular response to potentially mutagenic oxidants, but also appears to provide growth advantages to transformed cells by inhibiting apoptosis. In addition, selenocysteine-deficient or alkylated forms of thioredoxin reductase 1 have also demonstrated oxidative, pro-apoptotic activity. Therefore, a greater understanding of the role of thioredoxin reductase in redox initiated apoptotic processes is warranted. METHODOLOGY The role of thioredoxin reductase 1 in RKO cells was evaluated by attenuating endogenous thioredoxin reductase 1 expression with siRNA and then either inducing a selenium-deficient thioredoxin reductase or treatment with distinct redox challenges including, hydrogen peroxide, an oxidized lipid, 4-hydroxy-2-nonenol, and a nitric oxide donating prodrug. Thioredoxin redox status, cellular viability, and effector caspase activity were measured. CONCLUSIONS/SIGNIFICANCE In cells with attenuated endogenous thioredoxin reductase 1, a stably integrated selenocysteine-deficient form of the enzyme was induced but did not alter either the thioredoxin redox status or the cellular growth kinetics. The oxidized lipid and the nitric oxide donor demonstrated enhanced cytotoxicity when thioredoxin reductase 1 was knocked-down; however, the effect was more pronounced with the nitric oxide prodrug. These results are consistent with the hypothesis that attenuation of the thioredoxin-system can promote apoptosis in a nitric oxide-dependent manner.
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Lo WY, Balasubramanian A, Helsby NA. Hydrolysis of dinitrobenzamide phosphate prodrugs: the role of alkaline phosphatase. ACTA ACUST UNITED AC 2009; 24:1-16. [PMID: 19353998 DOI: 10.1515/dmdi.2009.24.1.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Phosphate prodrugs which undergo hydrolysis in vivo have been used to improve the solubility and pharmacokinetic properties of a number of drugs. Dinitrobenzamide mustards (DNBM) are examples of such drugs. We investigated the ability of purified alkaline phosphatase isoforms to dephosphorylate three DNBM phosphate prodrugs. In addition, the relative rate of dephosphorylation of these phosphate prodrugs in a number of tissues was determined. These phosphate prodrugs are indeed substrates for alkaline phosphatase, with time dependent formation of the hydrolysis product. Intestinal alkaline phosphatase (IAP) and placental alkaline phosphatase (PLAP) had the highest activity for these substrates and compound P2 was the most rapidly metabolised. Similarly, compound P2 had the shortest half life in mouse serum (t1/2 = 1.15 h) compared with P1 (t1/2 = 13.34 h) and P3 (t1/2 = 4.4 h). However, serum has very low dephosphorylase activity for these substrates compared with intestine and liver homogenates. In addition, there is little or no difference in the relative rate of dephosphorylation of each of the three compounds in mouse tissues in contrast to the pattern observed with purified alkaline phosphatase and mouse serum. Hence additional phosphatase enzymes may be involved in the metabolism of phosphate prodrugs in vivo.
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Affiliation(s)
- Wing-Yee Lo
- Department of Molecular Medicine and Pathology, University of Auckland, New Zealand
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