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1.
FEBS Open Bio ; 2024 Jun 28.
Article in English | MEDLINE | ID: mdl-38942739

ABSTRACT

Peripheral nerve injuries result in significant loss of motor and sensory function, and the slow rate of nerve regeneration can prolong recovery time. Thus, approaches that promote axonal regeneration are critical to improve the outcomes for patients with peripheral nerve injuries. In this study, we investigated the effects of Ficus carica L. (fig) and Vaccinium macrocarpon Ait. (cranberry), which are rich in phytochemicals with demonstrable and diverse medicinal properties, on nerve regeneration in a mouse model of sciatic nerve crush. Our investigation revealed that fig extract, but not cranberry extract, prevented the decline in muscle weight and nerve conduction velocity induced by nerve crush. The fig extract also mitigated motor function impairment, myelin thinning, and axon diameter reduction, indicating its potential to promote nerve regeneration. Furthermore, the fig extract enhanced macrophage infiltration into the nerve tissue, suggesting that it could ameliorate nerve injury by promoting tissue repair via increased macrophage infiltration. The study provides valuable insights into the potential of the fig extract as a novel agent promoting nerve regeneration. Further investigation into the mechanisms underlying the action of fig extracts is needed to translate these findings into clinical applications for patients with peripheral nerve injuries.

2.
BMC Nephrol ; 25(1): 124, 2024 Apr 08.
Article in English | MEDLINE | ID: mdl-38589827

ABSTRACT

BACKGROUND: Kidney transplant recipients (KTRs) are at risk of severe coronavirus disease 2019 (COVID-19), and even now that Omicron subvariants have become dominant, cases of severe disease are certain to occur. The aims of this retrospective study were to evaluate the efficacy of antiviral treatment for COVID-19 and to identify risk factors for severe disease in KTRs during Omicron subvariant-dominant periods. METHODS: A total of 65 KTRs diagnosed with COVID-19 who received antiviral treatment between July 2022 and September 2023 were analyzed. Mild cases received oral molnupiravir (MP) as outpatient therapy, while moderate or worse cases received intravenous remdesivir (RDV) as inpatient therapy. In principle, mycophenolate mofetil was withdrawn and switched to everolimus. We investigated the efficacy of antiviral treatment and compared the clinical parameters of mild/moderate and severe/critical cases to identify risk factors for severe COVID-19. RESULTS: Among 65 cases, 49 were mild, 6 were moderate, 9 were severe, and 1 was of critical severity. MP was administered to 57 cases; 49 (86%) improved and 8 (14%) progressed. RDV was administered to 16 cases; 14 (87%) improved and 2 (13%) progressed. Seventeen (26%) cases required hospitalization, and none died. Comparisons of the severe/critical group (n = 10) with the mild/moderate group (n = 55) demonstrated that the severe/critical group had a significantly higher median age (64 vs. 53 years, respectively; p = 0.0252), prevalence of diabetes (70% vs. 22%, respectively; p = 0.0047) and overweight/obesity (40% vs. 11%, respectively; p = 0.0393), as well as a significantly longer median time from symptom onset to initial antiviral therapy (3 days vs. 1 day, respectively; p = 0.0026). Multivariate analysis showed that a longer time from symptom onset to initial antiviral treatment was an independent risk factor for severe COVID-19 (p = 0.0196, odds ratio 1.625, 95% confidence interval 1.081-2.441). CONCLUSION: These findings suggest that a longer time from symptom onset to initial antiviral treatment is associated with a higher risk of severe COVID-19 in KTRs. Initiating antiviral treatment as early as possible is crucial for preventing severe outcomes; this represents a valuable insight into COVID-19 management in KTRs.


Subject(s)
COVID-19 , Cytidine/analogs & derivatives , Hydroxylamines , Kidney Transplantation , Humans , Retrospective Studies , Treatment Outcome , Risk Factors , Antiviral Agents/therapeutic use , Transplant Recipients
3.
Nutrients ; 16(1)2023 Dec 26.
Article in English | MEDLINE | ID: mdl-38201913

ABSTRACT

Leucine (Leu), an essential amino acid, is known to stimulate protein synthesis in the skeletal muscle via mTOR complex 1 (mTORC1) activation. However, the intrinsic contribution of other amino acids to Leu-mediated activation of mTORC1 signaling remains unexplored. This study aimed to identify amino acids that can promote mTORC1 activity in combination with Leu and to assess the effectiveness of these combinations in vitro and in vivo. We found that tyrosine (Tyr) enhanced Leu-induced phosphorylation of S6 kinase (S6K), an indicator of mTORC1 activity, although it exerted no such effect individually. This booster effect was observed in C2C12 cells, isolated murine muscle, and the skeletal muscles of mice orally administered the amino acids. To explore the molecular mechanisms underlying this Tyr-mediated booster effect, the expression of the intracellular Leu sensors, Sestrin1 and 2, was suppressed, and the cells were treated with Leu and Tyr. This suppression enabled Tyr alone to induce S6K phosphorylation and enhanced the booster effect, suggesting that Tyr possibly contributes to mTORC1 activation when Sestrin-GAP activity toward Rags 2 (GATOR2) is dissociated through Sestrin knockdown or the binding of Sestrins to Leu. Collectively, these results indicate that Tyr is a key regulator of Leu-mediated protein synthesis.


Subject(s)
Amino Acids , Tyrosine , Animals , Mice , Leucine/pharmacology , Muscle, Skeletal , Mechanistic Target of Rapamycin Complex 1 , Ribosomal Protein S6 Kinases
4.
Mol Oncol ; 16(6): 1329-1346, 2022 03.
Article in English | MEDLINE | ID: mdl-35148461

ABSTRACT

Patients with advanced bladder cancer are generally treated with a combination of chemotherapeutics, including gemcitabine, but the effect is limited due to acquisition of drug resistance. Thus, in this study, we investigated the mechanism of gemcitabine resistance. First, gemcitabine-resistant cells were established and resistance confirmed in vitro and in vivo. Small RNA sequencing analyses were performed to search for miRNAs involved in gemcitabine resistance. miR-99a-5p, selected as a candidate miRNA, was downregulated compared to its parental cells. In gain-of-function studies, miR-99a-5p inhibited cell viabilities and restored sensitivity to gemcitabine. RNA sequencing analysis was performed to find the target gene of miR-99a-5p. SMARCD1 was selected as a candidate gene. Dual-luciferase reporter assays showed that miR-99a-5p directly regulated SMARCD1. Loss-of-function studies conducted with si-RNAs revealed suppression of cell functions and restoration of gemcitabine sensitivity. miR-99a-5p overexpression and SMARCD1 knockdown also suppressed gemcitabine-resistant cells in vivo. Furthermore, ß-galactosidase staining showed that miR-99a-5p induction and SMARCD1 suppression contributed to cellular senescence. In summary, tumor-suppressive miR-99a-5p induced cellular senescence in gemcitabine-resistant bladder cancer cells by targeting SMARCD1.


Subject(s)
MicroRNAs , Urinary Bladder Neoplasms , Cell Line, Tumor , Cell Proliferation , Cellular Senescence/genetics , Chromosomal Proteins, Non-Histone/genetics , Deoxycytidine/analogs & derivatives , Gene Expression Regulation, Neoplastic , Humans , MicroRNAs/genetics , Urinary Bladder Neoplasms/drug therapy , Urinary Bladder Neoplasms/genetics , Gemcitabine
5.
Nutrients ; 13(7)2021 Jul 05.
Article in English | MEDLINE | ID: mdl-34371820

ABSTRACT

Morphological changes in neuromuscular junctions (NMJs), which are synapses formed between α-motor neurons and skeletal muscle fibers, are considered to be important in age-related motor dysfunction. We have previously shown that the intake of dietary milk fat globule membrane (MFGM) combined with exercise attenuates age-related NMJ alterations in the early phase of aging. However, it is unclear whether the effect of MFGM with exercise on age-related NMJ alterations persists into old age, and whether intervention from old age is still effective when age-related changes in NMJs have already occurred. In this study, 6- or 18-month-old mice were treated with a 1% MFGM diet and daily running wheel exercise until 23 or 24 months of age, respectively. MFGM treatment with exercise was effective in suppressing the progression of age-related NMJ alterations in old age, and even after age-related changes in NMJs had already occurred. Moreover, the effect of MFGM intake with exercise was not restricted to NMJs but extended to the structure and function of peripheral nerves. This study demonstrates that MFGM intake with exercise may be a novel approach for improving motor function in the elderly by suppressing age-related NMJ alterations.


Subject(s)
Aging/physiology , Animal Nutritional Physiological Phenomena/drug effects , Glycolipids/administration & dosage , Glycoproteins/administration & dosage , Neuromuscular Junction/drug effects , Physical Conditioning, Animal/physiology , Animals , Dietary Supplements , Lipid Droplets , Mice , Motor Neurons/drug effects , Muscle Fibers, Skeletal/drug effects , Synapses/drug effects
6.
iScience ; 23(8): 101385, 2020 Aug 21.
Article in English | MEDLINE | ID: mdl-32758427

ABSTRACT

Muscle denervation at the neuromuscular junction (NMJ), the essential synapse between motor neuron and skeletal muscle, is associated with age-related motor impairment. Therefore, improving muscle innervation at aged NMJs may be an effective therapeutic strategy for treating the impairment. We previously demonstrated that the muscle protein Dok-7 plays an essential role in NMJ formation, and, indeed, its forced expression in muscle enlarges NMJs. Moreover, therapeutic administration of an adeno-associated virus vector encoding human Dok-7 (DOK7 gene therapy) suppressed muscle denervation and enhanced motor activity in a mouse model of amyotrophic lateral sclerosis (ALS). Here, we show that DOK7 gene therapy significantly enhances motor function and muscle strength together with NMJ innervation in aged mice. Furthermore, the treated mice showed greatly increased compound muscle action potential (CMAP) amplitudes compared with the controls, suggesting enhanced neuromuscular transmission. Thus, therapies aimed at enhancing NMJ innervation have potential for treating age-related motor impairment.

7.
PLoS One ; 15(7): e0236119, 2020.
Article in English | MEDLINE | ID: mdl-32667929

ABSTRACT

The alcohol-abuse drug disulfiram has antitumor effects against diverse cancer types via inhibition of the ubiquitin-proteasome protein nuclear protein localization protein 4 (NPL4). However, the antitumor effects of NPL4 and disulfiram in clear cell renal cell carcinoma (ccRCC) are unclear. Here, we evaluated the therapeutic potential of targeting the ubiquitin-proteasome pathway using disulfiram and RNA interference and investigated the mechanisms underlying disulfiram in ccRCC. According to data from The Cancer Genome Atlas, NPL4 mRNA expression was significantly upregulated in clinical ccRCC samples compared with that in normal kidney samples, and patients with high NPL4 expression had poor overall survival compared with patients with low NPL4 expression. Disulfiram and NPL4 siRNA inhibited ccRCC cell proliferation in vitro, and disulfiram inhibited ccRCC tumor growth in a xenograft model. Synergistic antiproliferative effects were observed for combination treatment with disulfiram and sunitinib in vitro and in vivo. In RCC cells from mice treated with disulfiram and/or sunitinib, several genes associated with serine biosynthesis and aldose reductase were downregulated in cells treated with disulfiram or sunitinib alone and further downregulated in cells treated with both disulfiram and sunitinib. These findings provided insights into the mechanisms of disulfiram and suggested novel therapeutic strategies for RCC treatment.


Subject(s)
Carcinoma, Renal Cell/drug therapy , Disulfiram/pharmacology , Drug Repositioning/methods , Drug Resistance, Neoplasm/drug effects , Kidney Neoplasms/drug therapy , Nuclear Proteins/antagonists & inhibitors , Acetaldehyde Dehydrogenase Inhibitors/pharmacology , Animals , Apoptosis , Biomarkers, Tumor/genetics , Biomarkers, Tumor/metabolism , Carcinoma, Renal Cell/metabolism , Carcinoma, Renal Cell/pathology , Cell Proliferation , Female , Gene Expression Regulation, Neoplastic , Humans , Kidney Neoplasms/metabolism , Kidney Neoplasms/pathology , Mice , Mice, Inbred BALB C , Mice, Nude , Nuclear Proteins/genetics , Nuclear Proteins/metabolism , Prognosis , RNA, Small Interfering/genetics , Tumor Cells, Cultured , Xenograft Model Antitumor Assays
8.
Mol Oncol ; 14(9): 2190-2202, 2020 09.
Article in English | MEDLINE | ID: mdl-32386122

ABSTRACT

d-3-Phosphoglycerate dehydrogenase (PHGDH) conducts an important step in the synthesis of serine. Importantly, the PHGDH gene is often amplified in certain cancers. Our previous studies revealed that PHGDH gene amplification was associated with poor overall survival in clear cell renal cell carcinoma (ccRCC) and that metabolic reprogramming of serine synthesis through PHGDH recruitment allowed ccRCC cells to survive in unfavorable environments. There have been no investigations of the role of PHGDH expression in bladder cancer (BC). In this investigation, we examined the clinical importance of PHDGH in BC. Furthermore, we asked whether PHGDH expression could be exploited for BC therapy. Finally, we investigated the regulatory mechanisms that modulated the expression of PHGDH. Using data from The Cancer Genome Atlas, we found that patients with high-grade BC had significantly higher PHGDH expression levels than did those with low-grade BC. In addition, patients with high PHGDH expression did not survive as long as those with low expression. PHGDH downregulation by si-RNAs or an inhibitor in BC cell lines significantly inhibited proliferative ability and induced apoptosis. Furthermore, combined treatment using a PHGDH inhibitor and gemcitabine/cisplatin achieved synergistic tumor suppression compared to use of a single agent both in vitro as well as in vivo. Mechanistic analyses of PHGDH regulation showed that PHGDH expression might be associated with DNA copy number and hypomethylation in BC. These findings suggest novel therapeutic strategies could be used in BC. Finally, our data enhance our understanding of the role of PHGDH in BC.


Subject(s)
Cisplatin/therapeutic use , DNA Methylation/genetics , Deoxycytidine/analogs & derivatives , Gene Expression Regulation, Neoplastic , Molecular Targeted Therapy , Phosphoglycerate Dehydrogenase/genetics , Promoter Regions, Genetic/genetics , Urinary Bladder Neoplasms/drug therapy , Urinary Bladder Neoplasms/genetics , Animals , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Cell Line, Tumor , Cisplatin/pharmacology , Deoxycytidine/pharmacology , Deoxycytidine/therapeutic use , Down-Regulation/drug effects , Down-Regulation/genetics , Female , Gene Expression Regulation, Enzymologic/drug effects , Gene Expression Regulation, Neoplastic/drug effects , Humans , Mice, Inbred BALB C , Mice, Nude , Phosphoglycerate Dehydrogenase/antagonists & inhibitors , Phosphoglycerate Dehydrogenase/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Urinary Bladder Neoplasms/enzymology , Gemcitabine
9.
PLoS One ; 15(5): e0232545, 2020.
Article in English | MEDLINE | ID: mdl-32379831

ABSTRACT

Exosomes are 40-100 nm nano-sized extracellular vesicles. They are released from many cell types and move into the extracellular space, thereby transferring their components to recipient cells. Exosomes are receiving increasing attention as novel structures participating in intracellular communication. RAB27B is one of the leading proteins involved in exosome secretion, and oncogenic effects have been reported in several cancers. In recent years, molecularly targeted agents typified by sunitinib are widely used for the treatment of metastatic or recurrent renal cell carcinoma (RCC). However, intrinsic or acquired resistance to sunitinib has become a major issue. The present study aimed to elucidate the role of RAB27B in RCC including sunitinib-resistant and its role in exosomes. Bioinformatic analyses revealed that high expression of RAB27B correlates with progression of RCC. The expression of RAB27B protein in RCC cell lines was significantly enhanced compared with that in normal kidney cell lines. Furthermore, RAB27B protein expression was enhanced in all of the tested sunitinib-resistant RCC cell lines compared to parental cells. Although no specific effect of RAB27B on exosomes was identified in RCC cells, loss-of-function studies demonstrated that knockdown of RAB27B suppressed cell proliferation, migration and invasive activities. Moreover, anti-tumor effects of RAB27B downregulation were also observed in sunitinib-resistant RCC cells. RNA sequence and pathway analysis suggested that the oncogenic effects of RAB27B might be associated with MAPK and VEGF signaling pathways. These results showed that RAB27B is a prognostic marker and a novel therapeutic target in sunitinib-sensitive and -resistant RCCs. Further analyses should improve our understanding of sunitinib resistance in RCC.


Subject(s)
Antineoplastic Agents/therapeutic use , Carcinoma, Renal Cell/metabolism , Exosomes/metabolism , Kidney Neoplasms/metabolism , Sunitinib/therapeutic use , rab GTP-Binding Proteins/metabolism , Blotting, Western , Carcinoma, Renal Cell/drug therapy , Cell Line, Tumor , Drug Resistance, Neoplasm , Humans , Kidney/metabolism , Kidney Neoplasms/drug therapy
10.
Cancer Sci ; 111(5): 1607-1618, 2020 May.
Article in English | MEDLINE | ID: mdl-32232883

ABSTRACT

Sunitinib, a multitargeted receptor tyrosine kinase inhibitor including vascular endothelial growth factor, has been widely used as a first-line treatment against metastatic renal cell carcinoma (mRCC). However, mRCC often acquires resistance to sunitinib, rendering it difficult to treat with this agent. Recently, Rapalink-1, a drug that links rapamycin and the mTOR kinase inhibitor MLN0128, has been developed with excellent therapeutic effects against breast cancer cells carrying mTOR resistance mutations. The aim of the present study was to evaluate the in vitro and in vivo therapeutic efficacy of Rapalink-1 against renal cell carcinoma (RCC) compared to temsirolimus, which is commonly used as a small molecule inhibitor of mTOR and is a derivative of rapamycin. In comparison with temsirolimus, Rapalink-1 showed significantly greater effects against proliferation, migration, invasion and cFolony formation in sunitinib-naïve RCC cells. Inhibition was achieved through suppression of the phosphorylation of substrates in the mTOR signal pathway, such as p70S6K, eukaryotic translation initiation factor 4E-binding protein 1 (4EBP1) and AKT. In addition, Rapalink-1 had greater tumor suppressive effects than temsirolimus against the sunitinib-resistant 786-o cell line (SU-R 786-o), which we had previously established, as well as 3 additional SU-R cell lines established here. RNA sequencing showed that Rapalink-1 suppressed not only the mTOR signaling pathway but also a part of the MAPK signaling pathway, the ErbB signaling pathway and ABC transporters that were associated with resistance to several drugs. Our study suggests the possibility of a new treatment option for patients with RCC that is either sunitinib-sensitive or sunitinib-resistant.


Subject(s)
Carcinoma, Renal Cell/drug therapy , Drug Resistance, Neoplasm/drug effects , Kidney Neoplasms/drug therapy , Protein Kinase Inhibitors/pharmacology , Sirolimus/analogs & derivatives , Sunitinib/pharmacology , TOR Serine-Threonine Kinases/antagonists & inhibitors , Animals , Apoptosis/drug effects , Carcinoma, Renal Cell/metabolism , Carcinoma, Renal Cell/pathology , Cell Cycle/drug effects , Cell Line, Tumor , Cell Movement/drug effects , Cell Proliferation/drug effects , Female , Humans , Kidney Neoplasms/metabolism , Kidney Neoplasms/pathology , Mice , Mice, Nude , Protein Kinase Inhibitors/therapeutic use , Signal Transduction/drug effects , Sirolimus/pharmacology , Sirolimus/therapeutic use , Sunitinib/therapeutic use , TOR Serine-Threonine Kinases/metabolism
11.
J Physiol Sci ; 69(6): 931-938, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31482469

ABSTRACT

Motor units are generally recruited from the smallest to the largest following the size principle, while cutaneous stimulation has the potential to affect spinal motor control. We aimed to examine the effects of stimulating transient receptor potential channel sub-family M8 (TRPM8) combined with exercise on the modulation of spinal motor neuron (MN) excitability. Mice were topically administrated 1.5% icilin on the hindlimbs, followed by treadmill stepping. Spinal cord sections were immunostained with antibodies against c-fos and choline acetyltransferase. Icilin stimulation did not change the number of c-fos+ MNs, but increased the average soma size of the c-fos+ MNs during low-speed treadmill stepping. Furthermore, icilin stimulation combined with stepping increased c-fos+ cholinergic interneurons near the central canal, which are thought to modulate MN excitability. These findings suggest that TRPM8-mediated cutaneous stimulation with low-load exercise promotes preferential recruitment of large MNs and is potentially useful as a new training method for rehabilitation.


Subject(s)
Motor Neurons/physiology , Physical Conditioning, Animal , Pyrimidinones/pharmacology , TRPM Cation Channels/metabolism , Animals , Exercise Test , Gene Expression Regulation/drug effects , Male , Mice , Mice, Inbred C57BL , Proto-Oncogene Proteins c-fos/genetics , Proto-Oncogene Proteins c-fos/metabolism , Skin/drug effects , TRPM Cation Channels/genetics
12.
Int J Oncol ; 54(6): 2222-2236, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30942440

ABSTRACT

miRNA­223 (miR­223) has been reported to function not only as a tumor suppressor, but also as an oncogenic microRNA (miRNA or miR) in various cancer cells. Therefore, the functional role of miR­223 has not been elucidated to date, at least to the best of our knowledge. We previously performed the deep sequencing analysis of clinical bladder cancer (BC) specimens. It was revealed that miR­223 expression was significantly downregulated in BC, suggesting that miR­223 functions as a tumor suppressor miRNA in BC. The aim of this study was to investigate the functional roles of miR­223 and to identify its targets in BC. The expression levels of miR­223 were significantly decreased in our clinical BC specimens. The Cancer Genome Atlas (TCGA) database indicated that miR­223 expression was related to lymphovascular invasion and distant metastasis. The restoration of miR­223 expression significantly inhibited tumor aggressiveness and induced apoptosis via caspase­3/7 activation in BC cells. WD repeat domain 62 (WDR62), a candidate target of miR­223 according to in silico analyses, has been previously proposed to play a role in neurodevelopment. Direct binding between WDR62 and miR­223 was confirmed by luciferase assay. The TCGA database revealed positive associations between WDR62 mRNA expression and a higher tumor grade and stage in BC. The knockdown of WDR62 significantly inhibited tumor aggressiveness and induced the apoptosis of BC cells. On the whole, the findings of this study reveal a novel miR­223 target, oncogenic WDR62, and provided insight into the oncogenesis of BC.


Subject(s)
Gene Expression Regulation, Neoplastic , MicroRNAs/metabolism , Nerve Tissue Proteins/genetics , Oncogene Proteins/genetics , Urinary Bladder Neoplasms/genetics , Adult , Aged , Aged, 80 and over , Apoptosis/genetics , Cell Cycle Proteins , Cell Line, Tumor , Cystectomy , Datasets as Topic , Female , Gene Knockdown Techniques , Humans , Male , Middle Aged , Neoplasm Grading , Urinary Bladder/pathology , Urinary Bladder/surgery , Urinary Bladder Neoplasms/pathology , Urinary Bladder Neoplasms/surgery
13.
Int J Oncol ; 54(5): 1759-1770, 2019 May.
Article in English | MEDLINE | ID: mdl-30816432

ABSTRACT

Sunitinib is the most common primary molecular­targeted agent for metastatic clear cell renal cell carcinoma (ccRCC); however, intrinsic or acquired sunitinib resistance has become a significant problem in medical practice. The present study focused on microRNA (miR)­99a­3p, which was significantly downregulated in clinical sunitinib­resistant ccRCC tissues in previous screening analyses, and investigated the molecular network associated with it. The expression levels of miR­99a­3p and its candidate target genes were evaluated in RCC cells, including previously established sunitinib­resistant 786­o (SU­R­786­o) cells, and clinical ccRCC tissues, using reverse transcription­quantitative polymerase chain reaction. Gain­of­function studies demonstrated that miR­99a­3p significantly suppressed cell proliferation and colony formation in RCC cells, including the SU­R­786­o cells, by inducing apoptosis. Based on in silico analyses and RNA sequencing data, followed by luciferase reporter assays, ribonucleotide reductase regulatory subunit­M2 (RRM2) was identified as a direct target of miR­99a­3p in the SU­R­786­o cells. Loss­of­function studies using small interfering RNA against RRM2 revealed that cell proliferation and colony growth were significantly inhibited via induction of apoptosis, particularly in the SU­R­786­o cells. Furthermore, the RRM2 inhibitor Didox (3,4­dihydroxybenzohydroxamic acid) exhibited anticancer effects in the SU­R­786­o cells and other RCC cells. To the best of our knowledge, this is the first report demonstrating that miR­99a­3p directly regulates RRM2. Identifying novel genes targeted by tumor­suppressive miR­99a­3p in sunitinib­resistant RCC cells may improve our understanding of intrinsic or acquired resistance and facilitate the development of novel therapeutic strategies.


Subject(s)
Carcinoma, Renal Cell/genetics , Drug Resistance, Neoplasm , Kidney Neoplasms/genetics , MicroRNAs/genetics , Ribonucleoside Diphosphate Reductase/genetics , Adult , Aged , Aged, 80 and over , Carcinoma, Renal Cell/drug therapy , Carcinoma, Renal Cell/metabolism , Cell Line, Tumor , Cell Proliferation/drug effects , Gene Expression Regulation, Neoplastic/drug effects , Humans , Hydroxamic Acids/pharmacology , Kidney Neoplasms/drug therapy , Kidney Neoplasms/metabolism , Male , Middle Aged , Ribonucleoside Diphosphate Reductase/metabolism , Sunitinib/pharmacology
14.
Int J Oncol ; 53(2): 725-736, 2018 Aug.
Article in English | MEDLINE | ID: mdl-29901113

ABSTRACT

The active form of the small GTPase RAS binds to downstream effectors to promote cell growth and proliferation. RAS signal enhancement contributes to tumorigenesis, invasion, and metastasis in various different cancers. HRAS proto-oncogene GTPase (HRAS), one of the RAS isoforms, was the first human oncogene for which mutations were reported in T24 bladder cancer (BC) cells in 1982, and HRAS mutation or upregulation has been reported in several cancers. According to data from The Cancer Genome Atlas, HRAS expression was significantly upregulated in clinical BC samples compared to healthy samples (P=0.0024). HRAS expression was also significantly upregulated in BC with HRAS mutation compared to patients without HRAS mutation (P<0.0001). The tumor suppressive effect of salirasib, a RAS inhibitor, has been reported in several cancer types, but only at relatively high concentrations. As such, RAS inhibitors have not been used for clinical applications. The aim of the current study was to investigate the therapeutic potential of targeting HRAS using salirasib and small interfering RNA (siRNA) and to characterize the mechanism by which HRAS functions using recently developed quantitative in vitro proteome-assisted multiple reaction monitoring for protein absolute quantification (iMPAQT), in BC cells. iMPAQT allows measurement of the absolute abundance of any human protein with the high quantitative accuracy. Salirasib and siRNA targeting of HRAS inhibited cell proliferation, migration and invasion in HRAS wild type and HRAS-mutated cell lines. Proteomic analyses revealed that several metabolic pathways, including the oxidative phosphorylation pathway and glycolysis, were significantly downregulated in salirasib-treated BC cells. However, the expression levels of hexokinase 2, phosphoglycerate kinase 1, pyruvate kinase, muscle (PKM)1, PKM2 and lactate dehydrogenase A, which are downstream of RAS and target genes of hypoxia inducible factor-1α, were not notably downregulated, which may explain the high concentration of salirasib required to inhibit cell viability. These findings provide insight into the mechanisms of salirasib, and suggest the need for novel therapeutic strategies to treat cancers such as BC.


Subject(s)
Antineoplastic Agents/administration & dosage , Farnesol/analogs & derivatives , Proto-Oncogene Proteins p21(ras)/genetics , Proto-Oncogene Proteins p21(ras)/metabolism , Salicylates/administration & dosage , Up-Regulation/drug effects , Urinary Bladder Neoplasms/drug therapy , Animals , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Cell Movement/drug effects , Cell Proliferation/drug effects , Farnesol/administration & dosage , Farnesol/pharmacology , Gene Expression Regulation, Neoplastic/drug effects , Gene Knockdown Techniques , Gene Regulatory Networks , Glycolysis/drug effects , Humans , Mice , Mutation , Oxidative Phosphorylation/drug effects , Proteomics , Proto-Oncogene Mas , Salicylates/pharmacology , Urinary Bladder Neoplasms/genetics , Urinary Bladder Neoplasms/metabolism , Xenograft Model Antitumor Assays
15.
Oncotarget ; 9(33): 23003-23017, 2018 May 01.
Article in English | MEDLINE | ID: mdl-29796168

ABSTRACT

Sunitinib is a standard molecular-targeted drug used as a first-line treatment for metastatic clear cell renal cell carcinoma (ccRCC); however, resistance to sunitinib has become a major problem in medical practice. Recently, bromodomain containing 4 (BRD4), a member of the bromodomain family proteins, was identified as a promising therapeutic target, and its inhibitor JQ1 has been shown to have inhibitory effects in various human cancers. However, the anti-cancer effects of JQ1 in ccRCC, particularly sunitinib-resistant ccRCC, are still unclear. Here, we aimed to elucidate the anti-cancer effects of JQ1 and the mechanisms underlying BRD4 inhibition in sunitinib-sensitive and -resistant ccRCCs. Analysis of The Cancer Genome Atlas (TCGA) ccRCC cohort showed that patients with high BRD4 expression had shorter overall survival than those with low expression. JQ1 treatment significantly inhibited tumor growth of sunitinib-sensitive and -resistant ccRCC cells in part through MYC regulation. Based on RNA sequencing analyses of ccRCC cells treated with JQ1 to elucidate the mechanisms other than MYC regulation, we identified several oncogenes that may be potential therapeutic targets or prognostic markers; patients with high expression of SCG5, SPOCD1, RGS19, and ARHGAP22 had poorer overall survival than those with low expression in TCGA ccRCC cohort. Chromatin immunoprecipitation assays revealed that these oncogenes may be promising BRD4 targets, particularly in sunitinib-resistant ccRCC cells. These results identified SCG5, SPOCD1, RGS19, and ARHGAP22 as potential prognostic markers and showed that BRD4 inhibition may have applications as a potential therapeutic approach in sunitinib-sensitive and -resistant ccRCC.

17.
Cancer Res ; 77(22): 6321-6329, 2017 11 15.
Article in English | MEDLINE | ID: mdl-28951458

ABSTRACT

Continuous activation of hypoxia-inducible factor (HIF) is important for progression of renal cell carcinoma (RCC) and acquired resistance to antiangiogenic multikinase and mTOR inhibitors. Recently, HIF2α antagonists PT2385 and PT2399 were developed and are being evaluated in a phase I clinical trial for advanced or metastatic clear cell RCC (ccRCC). However, resistance to HIF2α antagonists would be expected to develop. In this study, we identified signals activated by HIF2α deficiency as candidate mediators of resistance to the HIF2α antagonists. We established sunitinib-resistant tumor cells in vivo and created HIF2α-deficient variants of these cells using CRISPR/Cas9 technology. Mechanistic investigations revealed that a regulator of the serine biosynthesis pathway, phosphoglycerate dehydrogenase (PHGDH), was upregulated commonly in HIF2α-deficient tumor cells along with the serine biosynthesis pathway itself. Accordingly, treatment with a PHGDH inhibitor reduced the growth of HIF2α-deficient tumor cells in vivo and in vitro by inducing apoptosis. Our findings identify the serine biosynthesis pathway as a source of candidate therapeutic targets to eradicate advanced or metastatic ccRCC resistant to HIF2α antagonists. Cancer Res; 77(22); 6321-9. ©2017 AACR.


Subject(s)
Basic Helix-Loop-Helix Transcription Factors/antagonists & inhibitors , Carcinoma, Renal Cell/drug therapy , Kidney Neoplasms/drug therapy , Phosphoglycerate Dehydrogenase/metabolism , Serine/biosynthesis , Xenograft Model Antitumor Assays/methods , Animals , Basic Helix-Loop-Helix Transcription Factors/genetics , Basic Helix-Loop-Helix Transcription Factors/metabolism , CRISPR-Cas Systems , Carcinoma, Renal Cell/genetics , Carcinoma, Renal Cell/metabolism , Cell Line, Tumor , Enzyme Inhibitors/pharmacology , Female , Gene Expression Regulation, Neoplastic/drug effects , Humans , Indans/pharmacology , Kidney Neoplasms/genetics , Kidney Neoplasms/metabolism , Mice, Inbred BALB C , Mice, Nude , Molecular Targeted Therapy/methods , Phosphoglycerate Dehydrogenase/antagonists & inhibitors , Phosphoglycerate Dehydrogenase/genetics , Sulfones/pharmacology , Survival Analysis
18.
Exp Gerontol ; 97: 29-37, 2017 10 15.
Article in English | MEDLINE | ID: mdl-28729214

ABSTRACT

Age-related loss of skeletal muscle mass and function attenuates physical performance, and maintaining fine muscle innervation is known to play an important role in its prevention. We had previously shown that consumption of milk fat globule membrane (MFGM) with habitual exercise improves the muscle mass and motor function in humans and mice. Improvement of neuromuscular junction (NMJ) was suggested as one of the mechanisms underlying these effects. In this study, we evaluated the effect of MFGM intake combined with voluntary running (MFGM-VR) on morphological changes of NMJ and motor function in aging mice. Seven months following the intervention, the MFGM-VR group showed a significantly improved motor coordination in the rotarod test and muscle force in the grip strength test compared with the control group at 13 and 14months of age, respectively. In 14-month old control mice, the extensor digitorum longus muscle showed increased abnormal NMJs, such as fragmentation and denervation, compared with 6-month old young mice. However, such age-related deteriorations of NMJs were significantly suppressed in the MFGM-VR group. Increase in the expression of NMJ formation-related genes, such as agrin and LDL Receptor Related Protein 4 (LRP4), might contribute to this beneficial effect. Rotarod performance and grip strength showed significant negative correlation with the status of denervation and fragmentation of NMJs. These results suggest that MFGM intake with voluntary running exercise effectively suppresses age-related morphological deterioration of NMJ, thus contributing to improvement of motor function.


Subject(s)
Aging/physiology , Dietary Supplements , Glycolipids/administration & dosage , Glycoproteins/administration & dosage , Neuromuscular Junction/drug effects , Running , Agrin/genetics , Animals , Gene Expression Regulation , LDL-Receptor Related Proteins , Lipid Droplets , Male , Mice , Mice, Inbred BALB C , Motor Activity , Muscle Strength/drug effects , Muscle, Skeletal/drug effects , Receptors, LDL/genetics
19.
Br J Cancer ; 116(8): 1077-1087, 2017 Apr 11.
Article in English | MEDLINE | ID: mdl-28324890

ABSTRACT

BACKGROUND: Based on the microRNA (miRNA) signature of bladder cancer (BC) by deep sequencing, we recently found that several double-stranded mature miRNAs derived from the same pre-miRNAs were sufficiently expressed and acted as tumour suppressors by regulating common target genes in BC. Our deep-sequencing signature of BC showed that all miR-199 family members (miR-199a-3p/-5p and miR-199b-3p/-5p) were also downregulated. We hypothesised that these miRNAs may function as tumour suppressors by regulating common target genes. METHODS: Functional assays of BC cells were performed using transfection of mature miRNA. In silico analyses and luciferase reporter analyses were applied to identify target genes of these miRNAs. The overall survival of patients with BC in The Cancer Genome Atlas (TCGA) database was evaluated by the Kaplan-Meier method. RESULTS: Restoration of these miRNAs significantly inhibited cell migration and invasion in BC cells. Integrin α3 (ITGA3) was directly regulated by these miRNAs. The Cancer Genome Atlas database showed that patients with low pre-miR-199 family (miR-199a-1/-2 and miR-199b) expression exhibited significantly poorer overall survival compared with patients with high pre-miR-199 family expression. CONCLUSIONS: miR-199 family miRNAs functioned as tumour suppressors in BC cells by targeting ITGA3 and might be good prognostic markers for predicting survival in patients with BC.


Subject(s)
Gene Expression Regulation, Neoplastic , Integrin alpha3/metabolism , MicroRNAs/genetics , Urinary Bladder Neoplasms/genetics , Apoptosis , Biomarkers, Tumor , Blotting, Western , Cell Movement , Cell Proliferation , Humans , Immunoenzyme Techniques , Integrin alpha3/genetics , Neoplasm Staging , Prognosis , RNA, Messenger/genetics , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , Tumor Cells, Cultured , Urinary Bladder Neoplasms/metabolism , Urinary Bladder Neoplasms/pathology
20.
Skelet Muscle ; 6: 31, 2016.
Article in English | MEDLINE | ID: mdl-27713817

ABSTRACT

BACKGROUND: Cholinergic dysfunction occurs during aging and in a variety of diseases, including amyotrophic lateral sclerosis (ALS). However, it remains unknown whether changes in cholinergic transmission contributes to age- and disease-related degeneration of the motor system. Here we investigated the effect of moderately increasing levels of synaptic acetylcholine (ACh) on the neuromuscular junction (NMJ), muscle fibers, and motor neurons during development and aging and in a mouse model for amyotrophic lateral sclerosis (ALS). METHODS: Chat-ChR2-EYFP (VAChTHyp) mice containing multiple copies of the vesicular acetylcholine transporter (VAChT), mutant superoxide dismutase 1 (SOD1G93A), and Chat-IRES-Cre and tdTomato transgenic mice were used in this study. NMJs, muscle fibers, and α-motor neurons' somata and their axons were examined using a light microscope. Transcripts for select genes in muscles and spinal cords were assessed using real-time quantitative PCR. Motor function tests were carried out using an inverted wire mesh and a rotarod. Electrophysiological recordings were collected to examine miniature endplate potentials (MEPP) in muscles. RESULTS: We show that VAChT is elevated in the spinal cord and at NMJs of VAChTHyp mice. We also show that the amplitude of MEPPs is significantly higher in VAChTHyp muscles, indicating that more ACh is loaded into synaptic vesicles and released into the synaptic cleft at NMJs of VAChTHyp mice compared to control mice. While the development of NMJs was not affected in VAChTHyp mice, NMJs prematurely acquired age-related structural alterations in adult VAChTHyp mice. These structural changes at NMJs were accompanied by motor deficits in VAChTHyp mice. However, cellular features of muscle fibers and levels of molecules with critical functions at the NMJ and in muscle fibers were largely unchanged in VAChTHyp mice. In the SOD1G93A mouse model for ALS, increasing synaptic ACh accelerated degeneration of NMJs caused motor deficits and resulted in premature death specifically in male mice. CONCLUSIONS: The data presented in this manuscript demonstrate that increasing levels of ACh at the synaptic cleft promote degeneration of adult NMJs, contributing to age- and disease-related motor deficits. We thus propose that maintaining normal cholinergic signaling in muscles will slow degeneration of NMJs and attenuate loss of motor function caused by aging and neuromuscular diseases.


Subject(s)
Acetylcholine/metabolism , Aging , Amyotrophic Lateral Sclerosis/physiopathology , Neuromuscular Junction/physiology , Vesicular Acetylcholine Transport Proteins/metabolism , Amyotrophic Lateral Sclerosis/metabolism , Animals , Disease Models, Animal , Female , Male , Mice , Mice, Transgenic , Miniature Postsynaptic Potentials , Motor Neurons/metabolism , Muscle, Skeletal/metabolism , Muscle, Skeletal/physiology , Neuromuscular Junction/metabolism , RNA, Messenger/metabolism , Spinal Cord/metabolism , Survival Analysis , Vesicular Acetylcholine Transport Proteins/physiology
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