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1.
Radiat Res ; 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38779845

RESUMO

Radioresistant cancer cells are risk factors for recurrence and are occasionally detected in recurrent tumors after radiotherapy. Intratumor heterogeneity is believed to be a potential cause of treatment resistance. Heterogeneity in DNA content has also been reported in human colorectal cancer; however, little is known about how such heterogeneity changes with radiotherapy or how it affects cancer radioresistance. In the present study, we established radioresistant clone SW480RR cells after fractionated X-ray irradiation of human colorectal cancer-derived SW480.hu cells, which are composed of two cell populations with different chromosome numbers, and examined how cellular radioresistance changed with fractionated radiotherapy. Compared with the parental cell population, which mostly comprised cells with higher ploidy, the radioresistant clones showed lower ploidy and less initial DNA damage. The lower ploidy cells in the parental cell population were identified as having radioresistance prior to irradiation; thus, SW480RR cells were considered intrinsically radioresistant cells selected from the parental population through fractionated irradiation. This study presents a practical example of the emergence of radioresistant cells from a cell population with ploidy heterogeneity after irradiation. The most likely mechanism is the selection of an intrinsically radioresistant population after fractionated X-ray irradiation, with a background in which lower ploidy cells exhibit lower initial DNA damage.

2.
Free Radic Biol Med ; 218: 57-67, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38574976

RESUMO

Understanding the tumor redox status is important for efficient cancer treatment. Here, we noninvasively detected changes in the redox environment of tumors before and after cancer treatment in the same individuals using a novel compact and portable electron paramagnetic resonance imaging (EPRI) device and compared the results with glycolytic information obtained through autoradiography using 2-deoxy-2-[18F]fluoro-d-glucose ([18F]FDG). Human colon cancer HCT116 xenografts were used in the mice. We used 3-carbamoyl-PROXYL (3CP) as a paramagnetic and redox status probe for the EPRI of tumors. The first EPRI was followed by the intraperitoneal administration of buthionine sulfoximine (BSO), an inhibitor of glutathione synthesis, or X-ray irradiation of the tumor. A second EPRI was performed on the following day. Autoradiography was performed after the second EPRI. After imaging, the tumor sections were evaluated by histological analysis and the amount of reducing substances in the tumor was measured. BSO treatment and X-ray irradiation significantly decreased the rate of 3CP reduction in tumors. Redox maps of tumors obtained from EPRI can be compared with tissue sections of approximately the same cross section. BSO treatment reduced glutathione levels in tumors, whereas X-ray irradiation did not alter the levels of any of the reducing substances. Comparison of the redox map with the autoradiography of [18F]FDG revealed that regions with high reducing power in the tumor were active in glucose metabolism; however, this correlation disappeared after X-ray irradiation. These results suggest that the novel compact and portable EPRI device is suitable for multimodal imaging, which can be used to study tumor redox status and therapeutic efficacy in cancer, and for combined analysis with other imaging modalities.


Assuntos
Estudos de Viabilidade , Fluordesoxiglucose F18 , Glucose , Imagem Multimodal , Oxirredução , Animais , Humanos , Camundongos , Fluordesoxiglucose F18/metabolismo , Glucose/metabolismo , Imagem Multimodal/métodos , Espectroscopia de Ressonância de Spin Eletrônica/métodos , Butionina Sulfoximina/farmacologia , Autorradiografia , Células HCT116 , Neoplasias do Colo/metabolismo , Neoplasias do Colo/diagnóstico por imagem , Neoplasias do Colo/patologia , Compostos Radiofarmacêuticos/metabolismo , Tomografia por Emissão de Pósitrons/métodos , Ensaios Antitumorais Modelo de Xenoenxerto , Glutationa/metabolismo , Camundongos Nus
3.
Adv Sci (Weinh) ; 11(12): e2306586, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38225711

RESUMO

Caged compounds are frequently used in life science research. However, the light used to activate them is commonly absorbed and scattered by biological materials, limiting their use to basic research in cells or small animals. In contrast, hard X-rays exhibit high bio-permeability due to the difficulty of interacting with biological molecules. With the main goal of developing X-ray activatable caged compounds, azo compounds are designed and synthesized with a positive charge and long π-conjugated system to increase the reaction efficiency with hydrated electrons. The azo bonds in the designed compounds are selectively cleaved by X-ray, and the fluorescent substance Diethyl Rhodamine is released. Based on the results of experiments and quantum chemical calculations, azo bond cleavage is assumed to occur via a two-step process: a two-electron reduction of the azo bond followed by N─N bond cleavage. Cellular experiments also demonstrate that the azo bonds can be cleaved intracellularly. Thus, caged compounds that can be activated by an azo bond cleavage reaction promoted by X-ray are successfully generated.

4.
Anal Chem ; 95(8): 3940-3950, 2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36725678

RESUMO

Extracellular acidification indicates a metabolic shift in cancer cells and is, along with tissue hypoxia, a hallmark of tumor malignancy. Thus, non-invasive mapping of extracellular pH (pHe) is essential for researchers to understand the tumor microenvironment and to monitor tumor response to metabolism-targeting drugs. While electron paramagnetic resonance (EPR) has been successfully used to map pHe in mouse xenograft models, this method is not sensitive enough to map pHe with a moderate amount of exogenous pH-sensitive probes. Here, we show that a modified EPR system achieves twofold higher sensitivity by using the multiple harmonic detection (MHD) method and improves the robustness of pHe mapping in mouse xenograft models. Our results demonstrate that treatment of a mouse xenograft model of human-derived pancreatic ductal adenocarcinoma cells with the carbonic anhydrase IX (CAIX) inhibitor U-104 delays tumor growth with a concurrent tendency toward further extracellular acidification. We anticipate that EPR-based pHe mapping can be expanded to monitor the response of other metabolism-targeting drugs. Furthermore, pHe monitoring can also be used for the development of improved metabolism-targeting cancer treatments.


Assuntos
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Humanos , Animais , Camundongos , Espectroscopia de Ressonância de Spin Eletrônica/métodos , Antígenos de Neoplasias/metabolismo , Carcinoma Ductal Pancreático/patologia , Modelos Animais de Doenças , Concentração de Íons de Hidrogênio , Linhagem Celular Tumoral , Microambiente Tumoral
5.
J Neurosci ; 42(23): 4607-4618, 2022 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-35504726

RESUMO

Ubiquitin-specific protease 2 (USP2) participates in glucose metabolism in peripheral tissues such as the liver and skeletal muscles. However, the glucoregulatory role of USP2 in the CNS is not well known. In this study, we focus on USP2 in the ventromedial hypothalamus (VMH), which has dominant control over systemic glucose homeostasis. ISH, using a Usp2-specific probe, showed that Usp2 mRNA is present in VMH neurons, as well as other glucoregulatory nuclei, in the hypothalamus of male mice. Administration of a USP2-selective inhibitor ML364 (20 ng/head), into the VMH elicited a rapid increase in the circulating glucose level in male mice, suggesting USP2 has a suppressive role on glucose mobilization. ML364 treatment also increased serum norepinephrine concentration, whereas it negligibly affected serum levels of insulin and corticosterone. ML364 perturbated mitochondrial oxidative phosphorylation in neural SH-SY5Y cells and subsequently promoted the phosphorylation of AMP-activated protein kinase (AMPK). Consistent with these findings, hypothalamic ML364 treatment stimulated AMPKα phosphorylation in the VMH. Inhibition of hypothalamic AMPK prevented ML364 from increasing serum norepinephrine and blood glucose. Removal of ROS restored the ML364-evoked mitochondrial dysfunction in SH-SY5Y cells and impeded the ML364-induced hypothalamic AMPKα phosphorylation as well as prevented the elevation of serum norepinephrine and blood glucose levels in male mice. These results indicate hypothalamic USP2 attenuates perturbations in blood glucose levels by modifying the ROS-AMPK-sympathetic nerve axis.SIGNIFICANCE STATEMENT Under normal conditions (excluding hyperglycemia or hypoglycemia), blood glucose levels are maintained at a constant level. In this study, we used a mouse model to identify a hypothalamic protease controlling blood glucose levels. Pharmacological inhibition of USP2 in the VMH caused a deviation in blood glucose levels under a nonstressed condition, indicating that USP2 determines the set point of the blood glucose level. Modification of sympathetic nervous activity accounts for the USP2-mediated glucoregulation. Mechanistically, USP2 mitigates the accumulation of ROS in the VMH, resulting in attenuation of the phosphorylation of AMPK. Based on these findings, we uncovered a novel glucoregulatory axis consisting of hypothalamic USP2, ROS, AMPK, and the sympathetic nervous system.


Assuntos
Glicemia , Neuroblastoma , Sistema Nervoso Simpático , Ubiquitina Tiolesterase , Núcleo Hipotalâmico Ventromedial , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Glicemia/metabolismo , Glucose/metabolismo , Humanos , Masculino , Camundongos , Norepinefrina/metabolismo , Fosforilação Oxidativa , Espécies Reativas de Oxigênio/metabolismo , Sistema Nervoso Simpático/enzimologia , Sistema Nervoso Simpático/metabolismo , Ubiquitina Tiolesterase/metabolismo , Núcleo Hipotalâmico Ventromedial/enzimologia , Núcleo Hipotalâmico Ventromedial/metabolismo
6.
Transl Oncol ; 21: 101431, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35452996

RESUMO

Glutamine metabolism, known as glutaminolysis, is abnormally activated in many cancer cells with KRAS or BRAF mutations or active c-MYC. Glutaminolysis plays an important role in the proliferation of cancer cells with oncogenic mutations. In this study, we characterized radiation-induced cell death, which was enhanced by glutaminolysis inhibition in non-small cell lung cancer A549 and H460 cell lines with KRAS mutation. A clonogenic survival assay revealed that treatment with a glutaminase inhibitor, CB839, enhanced radiosensitivity. X-irradiation increased glutamate production, mitochondrial oxygen consumption, and ATP production, whereas CB839 treatment suppressed these effects. The data suggest that the enhancement of glutaminolysis-dependent energy metabolism for ATP production is important for survival after X-irradiation. Evaluation of the cell death phenotype revealed that glutaminolysis inhibitory treatment with CB839 or a low-glutamine medium significantly promoted the proliferation of ß-galactosidase-positive and IL-6/IL-8 secretory cells among X-irradiated tumor cells, corresponding to an increase in the senescent cell population. Furthermore, treatment with ABT263, a Bcl-2 family inhibitor, transformed senescent cells into apoptotic cells. The findings suggest that combination treatment with a glutaminolysis inhibitor and a senolytic drug is useful for efficient radiotherapy.

7.
Antioxid Redox Signal ; 36(1-3): 57-69, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-33847172

RESUMO

Aims: This work aimed to establish an accelerated imaging system for redox-sensitive mapping in a mouse tumor model using electron paramagnetic resonance (EPR) and nitroxyl radicals. Results: Sparse sampling of EPR spectral projections was demonstrated for a solution phantom. The reconstructed three-dimensional (3D) images with filtered back-projection (FBP) and compressed sensing image reconstruction were quantitatively assessed for the solution phantom. Mouse xenograft models of a human-derived pancreatic ductal adenocarcinoma cell line, MIA PaCa-2, were also measured for redox-sensitive mapping with the sparse sampling technique. Innovation: A short-lifetime redox-sensitive nitroxyl radical (15N-labeled perdeuterated Tempone) could be measured to map the decay rates of the EPR signals for the mouse xenograft models. Acceleration of 3D EPR image acquisition broadened the choices of nitroxyl radical probes with various redox sensitivities to biological environments. Conclusion: Sparse sampling of EPR spectral projections accelerated image acquisition in the 3D redox-sensitive mapping of mouse tumor-bearing legs fourfold compared with conventional image acquisition with FBP. Antioxid. Redox Signal. 36, 57-69.


Assuntos
Imageamento Tridimensional , Neoplasias , Animais , Espectroscopia de Ressonância de Spin Eletrônica/métodos , Humanos , Imageamento Tridimensional/métodos , Camundongos , Oxirredução , Imagens de Fantasmas
8.
Eur J Nucl Med Mol Imaging ; 49(3): 821-833, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34468781

RESUMO

PURPOSE: Eribulin, an inhibitor of microtubule dynamics, is known to show antitumor effects through its remodeling activity in the tumor vasculature. However, the extent to which the improvement of tumor hypoxia by eribulin affects radio-sensitivity remains unclear. We utilized 1-(2,2-dihydroxymethyl-3-18F-fluoropropyl)-2-nitroimidazole (18F-DiFA), a new PET probe for hypoxia, to investigate the effects of eribulin on tumor hypoxia and evaluate the radio-sensitivity during eribulin treatment. METHODS: Mice bearing human breast cancer MDA-MB-231 cells or human lung cancer NCI-H1975 cells were administered a single dose of eribulin. After administration, mice were injected with 18F-DiFA and pimonidazole, and tumor hypoxia regions were analyzed. For the group that received combined treatment with radiation, 18F-DiFA PET/CT imaging was performed before tumors were locally X-irradiated. Tumor size was measured every other day after irradiation. RESULTS: Eribulin significantly reduced 18F-DiFA accumulation levels in a dose-dependent manner. Furthermore, the reduction in 18F-DiFA accumulation levels by eribulin was most significant 7 days after treatment. These results were also supported by reduction of the pimonidazole-positive hypoxic region. The combined treatment showed significant retardation of tumor growth in comparison with the control, radiation-alone, and drug-alone groups. Importantly, tumor growth after irradiation was inversely correlated with 18F-DiFA accumulation. CONCLUSION: These results demonstrated that 18F-DiFA PET/CT clearly detected eribulin-induced tumor oxygenation and that eribulin efficiently enhanced the antitumor activity of radiation by improving tumor oxygenation.


Assuntos
Furanos , Cetonas , Neoplasias Pulmonares , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Hipóxia Tumoral , Animais , Linhagem Celular Tumoral , Xenoenxertos , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/patologia , Camundongos
9.
ACS Pharmacol Transl Sci ; 4(5): 1689-1701, 2021 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-34661083

RESUMO

Near-infrared photoimmunotherapy (NIR-PIT) employs molecularly targeted antibodies conjugated with a photoabsorbing silicon-phthalocyanine dye derivative which binds to cancer cells. Application of NIR light following binding of the antibody-photoabsorber conjugates (APCs) results in ligand release on the dye, dramatic changes in solubility of the APC-antigen complex, and rapid, irreversible cell membrane damage of cancer cells in a highly selective manner, resulting in a highly immunogenic cell death. Clinically, this process results in edema after treatment mediated by reactive oxygen species (ROS). Based on the chemical and biological mechanism of NIR-PIT cytotoxicity and edema formation, in order to minimize acute inflammatory edema without compromising therapeutic effects, l-sodium ascorbate (l-NaAA) was administered to quench harmful ROS and accelerate the ligand release reaction. l-NaAA suppressed acute edema by reducing ROS after NIR-PIT yet did not alter the therapeutic effects. NIR-PIT could be performed safely under existence of l-NaAA without side effects caused by unnecessary ROS production.

10.
Mol Ther Oncolytics ; 22: 143-151, 2021 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-34514095

RESUMO

Metformin has many anti-cancer effects, alone or in combination with radiation. However, the mechanism underlying its radio-sensitized effect is still unclear, especially for cancer stem-like cells (CSCs). Here, the radio-sensitized effect of metformin was investigated, and its mechanism was revealed in CSCs derived from canine osteosarcoma cell line (HMPOS), a canine osteosarcoma cell line. Spheroid cells (SCs) were used as CSCs-rich cells derived from sphere formation, and SCs were compared with normal adherent culture cells (ACs). The radio-sensitizing effect of metformin using clonogenic assay and tumor growth in mice xenograft model were evaluated, and the mechanism of its radio-sensitization focusing on mitochondrial function was revealed. Metformin significantly enhanced radio-sensitivity of SCs through its inhibition of the mitochondrial function, as shown by decreased oxygen consumption, decreased mitochondrial membrane potential, and decreased ATP production. Additionally, SCs had a higher ability of mitochondrial respiration than ACs, which may have caused difference of their sensitivity of metformin and irradiation. In conclusion, mitochondrial function might play an important role in the sensitivity of metformin and irradiation, and drugs that target mitochondrial respiration, such as metformin, are promising radio-sensitizers to target CSCs.

11.
Transl Oncol ; 14(11): 101212, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34461558

RESUMO

L-type amino acid transporter 1 (LAT1) is important for transporting neutral amino acids into cells. LAT1 expression is correlated with cancer malignancy, suggesting that LAT1 is a promising target for cancer therapy. JPH203, a potential novel drug targeting LAT1, has been shown to suppress tumor growth in various cancer cell lines. However, a combination study of JPH203 and radiation therapy has not been reported. Here, we examined the effects of JPH203 on radiosensitivity after irradiation in A549 and MIA Paca-2 cells. We showed that X-irradiation increased cellular neutral amino acid uptake via LAT1 in both cell lines. JPH203 inhibited the radiation-induced increase in neutral amino acid uptake. We demonstrated that JPH203, at minimally toxic concentrations, significantly sensitized cancer cells to radiation. JPH203 significantly downregulated mTOR activity and enhanced cellular senescence post-irradiation without reducing ATP and GSH levels. These results indicate that LAT1 inhibition by JPH203 sensitizes cancer cells to radiation by enhancing cellular senescence via mTOR downregulation. Thus, JPH203 may be a potent anti-cancer drug in combination with radiation therapy.

12.
J Radiat Res ; 62(4): 564-573, 2021 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-33912932

RESUMO

A post-exposure cohort study in Hiroshima and Nagasaki reported that low-dose exposure to radiation heightened the risk of cardiovascular diseases (CVD), such as stroke and myocardial infarction, by 14-18% per Gy. Moreover, the risk of atherosclerosis in the coronary arteries reportedly increases with radiation therapy of the chest, including breast and lung cancer treatment. Cellular senescence of vascular endothelial cells (ECs) is believed to play an important role in radiation-induced CVDs. The molecular mechanism of age-related cellular senescence is believed to involve genomic instability and DNA damage response (DDR); the chronic inflammation associated with senescence causes cardiovascular damage. Therefore, vascular endothelial cell senescence is believed to induce the pathogenesis of CVDs after radiation exposure. The findings of several prior studies have revealed that ionizing radiation (IR) induces cellular senescence as well as cell death in ECs. We have previously reported that DDR activates endothelial nitric oxide (NO) synthase, and NO production promotes endothelial senescence. Endothelial NO synthase (eNOS) is a major isoform expressed in ECs that maintains cardiovascular homeostasis. Therefore, radiation-induced NO production, a component of the DDR in ECs, may be involved in CVDs after radiation exposure. In this article, we describe the pathology of radiation-induced CVD and the unique radio-response to radiation exposure in ECs.


Assuntos
Envelhecimento/patologia , Doenças Cardiovasculares/etiologia , Dano ao DNA , Endotélio Vascular/patologia , Lesões por Radiação/complicações , Animais , Humanos , Óxido Nítrico/biossíntese , Estresse Oxidativo
13.
J Clin Biochem Nutr ; 67(3): 240-247, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33293764

RESUMO

Mitotic catastrophe is a form of cell death linked to aberrant mitosis caused by improper or uncoordinated mitotic progression. Abnormal centrosome amplification and mitotic catastrophe occur simultaneously, and some cells with amplified centrosomes enter aberrant mitosis, but it is not clear whether abnormal centrosome amplification triggers mitotic catastrophe. Here, to investigate whether radiation-induced abnormal centrosome amplification is essential for induction of radiation-induced mitotic catastrophe, centrinone-B, a highly selective inhibitor of polo-like kinase 4, was utilized to inhibit centrosome amplification, since polo-like kinase 4 is an essential kinase in centrosome duplication. When human cervical tumor HeLa cells and murine mammary tumor EMT6 cells were irradiated with 2.5 Gy of X-rays, cells with morphological features of mitotic catastrophe and the number of cells having >2 centrosomes increased in both cell lines. Although centrinone-B significantly inhibited radiation-induced abnormal centrosome amplification in both cell lines, such treatment did not change cell growth and significantly enhanced mitotic catastrophe in HeLa cells exposed to X-rays. In contrast, inhibition of centrosome amplification reduced cell growth and mitotic catastrophe in EMT6 cells exposed to X-rays. These results indicated that the role of radiation-induced abnormal centrosome amplification in radiation-induced mitotic catastrophe changes, depending on the cell type.

14.
Igaku Butsuri ; 40(1): 13-18, 2020.
Artigo em Japonês | MEDLINE | ID: mdl-32238677

RESUMO

Hypoxia has been known to be a feature associated with tumor radioresistance. So far, clinical strategies to overcome chronic hypoxia due to the limitation of the oxygen diffusion have been designed. However, intermittent or acute/cycling hypoxia, whose frequency can range between a few cycles per minutes to hours, is receiving increased attention, because this type of hypoxia has been reported to have an influence on tumor malignancy as well as treatment resistance via increased expression of pro-survival pathways. Therefore, a priori information on fluctuating hypoxia can be important in clinical treatment planning, but complicated dynamics makes it difficult to elucidate biological significance of intermittent hypoxia.Here, we illustrate the use of pulsed electron spin resonance imaging (ESRI) as a novel imaging method to directly monitor fluctuating oxygenation i.e. cycling hypoxia in transplanted tumors. A common resonator platform for both ESRI and magnetic resonance imaging (MRI) provided pO2 maps with anatomical guidance without positional movement. Oxygen images every 3 min in pO2 could visualize the rapid oxygen fluctuation and distinguish the cycling hypoxia and chronic hypoxia. Furthermore, we have examined the vascular renormalization process by longitudinally pO2 mapping during treatments with a multi-tyrosine kinase inhibitor sunitinib. Transient improvement in tumor oxygenation and the decrease of cycling tumor hypoxia were visualized by ESRI 2 to 4 days following antiangiogenic treatments. Radiation treatment during this time period of improved oxygenation by antiangiogenic therapy resulted in a synergistic delay in tumor growth.In conclusion, this ESRI technique combined with MRI, may offer a powerful clinical tool to noninvasively detect variable hypoxic status in tumors and to identify a window of vascular renormalization to maximize the effects of combination therapy with antiangiogenic drugs.


Assuntos
Neoplasias , Radiobiologia , Hipóxia Tumoral , Espectroscopia de Ressonância de Spin Eletrônica , Humanos , Hipóxia , Neoplasias/diagnóstico por imagem , Neoplasias/fisiopatologia , Oxigênio
15.
Nucleosides Nucleotides Nucleic Acids ; 39(1-3): 439-452, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31560250

RESUMO

The combination of low dose of radiation and an anticancer drug is a potent strategy for cancer therapy. Nucleoside analogs are known to have a radiosensitizing effects via the inhibition of DNA damage repair after irradiation. Certain types of nucleoside analogs have the inhibitory effects on RNA synthesis, but not DNA synthesis, with multiple functions in cell cycle modulation and apoptosis. In this review, the most up-to-date findings regarding radiosensitizing nucleoside analogs will be discussed, focusing especially on the mechanisms of action.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Nucleosídeos/análogos & derivados , Nucleosídeos/farmacologia , Radiossensibilizantes/farmacologia , Animais , Linhagem Celular Tumoral , Dano ao DNA , Modelos Animais de Doenças , Humanos , Estrutura Molecular , Purinas/química , Purinas/farmacologia , Pirimidinas/química , Pirimidinas/farmacologia , Radiação Ionizante , Radioterapia/efeitos adversos , Ensaios Antitumorais Modelo de Xenoenxerto
16.
Biochem Biophys Res Commun ; 522(1): 144-150, 2020 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-31757415

RESUMO

Mitochondrial dynamics are crucial for cellular survival in response to various stresses. Previously, we reported that Drp1 promoted mitochondrial fission after x-irradiation and its inhibition resulted in reduced cellular radiosensitivity and mitotic catastrophe. However, the mechanisms of radiation-induced mitotic catastrophe related to mitochondrial fission remain unclear. In this study, we investigated the involvement of cellular ATP production, ROS generation, and Ca2+ levels in mitotic catastrophe in EMT6 cells. Knockdown of Drp1 and Fis1, which are mitochondrial fission regulators, resulted in elongated mitochondria and significantly attenuated cellular radiosensitivity. Reduced mitochondrial fission mainly decreased mitotic catastrophe rather than necrosis and apoptosis after irradiation. Cellular ATP contents in Drp1 and Fis1 knockdown cells were similar to those in control cells. N-acetylcysteine and 2-glucopyranoside ascorbic acid have no effect on mitotic catastrophe after irradiation. The cellular [Ca2+]i level increased after irradiation, which was completely suppressed by Drp1 and Fis1 inhibition. Furthermore, BAPTA-AM significantly reduced radiation-induced mitotic catastrophe, indicating that cellular Ca2+ is a key mediator of mitotic catastrophe induction after irradiation. These results suggest that mitochondrial fission is associated with radiation-induced mitotic catastrophe via cytosolic Ca2+ regulation.


Assuntos
Neoplasias da Mama/metabolismo , Cálcio/metabolismo , Dinâmica Mitocondrial , Trifosfato de Adenosina/metabolismo , Animais , Neoplasias da Mama/patologia , Neoplasias da Mama/radioterapia , Linhagem Celular Tumoral , Feminino , Camundongos , Dinâmica Mitocondrial/efeitos da radiação , Mitose/efeitos da radiação , Tolerância a Radiação , Espécies Reativas de Oxigênio/metabolismo , Raios X
17.
Physiol Rep ; 7(14): e14193, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31353872

RESUMO

Ubiquitin-specific protease 2 (USP2) is considered to participate in the differentiation of myoblasts to myotubes, however, its functions in myoblasts under growth conditions remain elusive. In this study, we analyzed the physiological roles of USP2 in myoblasts using Usp2 knockout (KO) C2C12 cells as well as a USP2 specific inhibitor. In addition to the disruption of differentiation, clustered regularly interspaced short palindromic repeats/Cas9-generated Usp2KO cells exhibited inhibition of proliferation compared to parental C2C12 cells. Usp2KO cells reduced the accumulation of intracellular adenosine triphosphate (ATP) content and oxygen consumption. Moreover, Usp2KO cells had fragmented mitochondria, suggesting that mitochondrial respiration was inactive. The deficiency of Usp2 did not affect the enzymatic activities of respiratory chain complexes I, III, IV, and V. However, mitochondrial membrane permeability-evaluated using calcein AM-cobalt staining-was increased in Usp2KO cells. The membrane potential of Usp2KO cells was clearly decreased. Usp2KO cells accumulated reactive oxygen species (ROS) in the mitochondria. The USP2-selective inhibitor ML364 also increased the levels of mitochondrial ROS, and modulated the membrane potential and morphology of the mitochondria. These effects were followed by a decrement in the intracellular content of ATP. Based on these findings, we speculate that USP2 may be involved in maintaining the integrity of the mitochondrial membrane. This process ensures the supply of ATP in myoblasts, presumably leading to proliferation and differentiation.


Assuntos
Trifosfato de Adenosina/metabolismo , Mitocôndrias Musculares/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Ubiquitina Tiolesterase/metabolismo , Animais , Linhagem Celular , Inibidores Enzimáticos/farmacologia , Potencial da Membrana Mitocondrial , Camundongos , Mitocôndrias Musculares/efeitos dos fármacos , Mioblastos/efeitos dos fármacos , Mioblastos/metabolismo , Fosforilação Oxidativa , Ubiquitina Tiolesterase/antagonistas & inibidores , Ubiquitina Tiolesterase/genética
18.
Nutr Cancer ; 71(7): 1153-1164, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31179755

RESUMO

Many functional foods or physiologically active ingredients derived from plants and animals are actively being investigated for their role in chronic disease prevention. Squalene (SQ) is found as active ingredient in the functional foods predominantly present in olive oil and shark liver oil. It is known that during chemotherapy anticancer drugs induce inflammation. SQ has been thought to prevent and suppress inflammation; however, there is little direct evidence available. We examined the adjuvant effect of SQ on tumor-transplanted mice along with anticancer drug doxorubicin (DOX). SQ significantly suppressed the DOX-induced increase in prostaglandin E2 (PGE2) concentration (P < 0.05) in plasma of tumor-bearing mice. SQ inhibited the numbers of writhing response (P < 0.05), formalin-induced pain and decreased COX-2 and substance P expression in the tumor tissue compared to control mice and also enhanced the antitumor efficacy of DOX in allograft mice. Thus, SQ reduces inflammation through modulation of PGE2 production indicating its potential as an adjuvant during chemotherapy in tumor-bearing mice.


Assuntos
Analgésicos/farmacologia , Anti-Inflamatórios não Esteroides/farmacologia , Alimento Funcional , Esqualeno/farmacologia , Aloenxertos , Ração Animal , Animais , Linhagem Celular Tumoral , Neoplasias do Colo/tratamento farmacológico , Ciclo-Oxigenase 2/metabolismo , Inibidores de Ciclo-Oxigenase 2/farmacologia , Dinoprostona/sangue , Doxorrubicina/administração & dosagem , Camundongos Endogâmicos BALB C , Esqualeno/administração & dosagem , Substância P/metabolismo
19.
FASEB J ; 33(4): 5196-5207, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30624970

RESUMO

Bone marrow provides progenitors of several types of cells, including muscle and white adipocytes, ensuring peripheral tissue homeostasis. However, the role of bone marrow-derived cells (BMCs) in induction of thermogenic adipocytes is unresolved. The purpose of this study is to examine whether BMCs are involved in the emergence of thermogenic adipocytes through adrenergic activation. Irradiation of mice with 8 Gy of X-ray-depleted BMCs and peripheral blood mononucleated cells (PBMCs), which in turn impaired induction of uncoupling protein 1 (UCP1) through administration of ß3 adrenergic receptor agonist, CL 316,243 (CL), in inguinal white adipose tissue (iWAT). In contrast, CL-induced UCP1 induction in brown adipose tissue was unaffected by BMC depletion. Transplantation of normal BMCs into mice depleted of BMCs recovered PBMC levels and rescued the ability of iWAT browning by CL. Furthermore, analyses of mice transplanted with green fluorescent protein (GFP)-labeled BMCs revealed that the number of GFP-positive BMCs and PBMCs were significantly decreased by CL and that GFP-positive stromal cells and GFP-positive UCP1-expressing multilocular adipocytes appeared in iWAT after CL administration, demonstrating differentiation of BMC-derived preadipocytes into UCP1-expressing thermogenic adipocytes. These results unveiled a crucial role of the BMC as a nonresident origin for a subset of thermogenic adipocytes, contributing to browning of white adipose tissue.-Yoneshiro, T., Shin, W., Machida, K., Fukano, K., Tsubota, A., Chen, Y., Yasui, H., Inanami, O., Okamatsu-Ogura, Y., Kimura, K. Differentiation of bone marrow-derived cells toward thermogenic adipocytes in white adipose tissue induced by the ß3 adrenergic stimulation.


Assuntos
Adipócitos/citologia , Tecido Adiposo Branco/citologia , Células da Medula Óssea/citologia , Células da Medula Óssea/metabolismo , Diferenciação Celular/fisiologia , Receptores Adrenérgicos beta 3/metabolismo , Agonistas de Receptores Adrenérgicos beta 3/farmacologia , Animais , Western Blotting , Transplante de Medula Óssea , Endotélio Vascular/citologia , Endotélio Vascular/metabolismo , Citometria de Fluxo , Imunofluorescência , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteína Desacopladora 1/metabolismo
20.
Anal Chem ; 90(23): 13938-13945, 2018 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-30372035

RESUMO

An electron paramagnetic resonance (EPR)-based method for noninvasive three-dimensional extracellular pH mapping was developed using a pH-sensitive nitroxyl radical as an exogenous paramagnetic probe. Fast projection scanning with a constant magnetic field sweep enabled the acquisition of four-dimensional (3D spatial +1D spectral) EPR images within 7.5 min. Three-dimensional maps of pH were reconstructed by processing the pH-dependent spectral information on the images. To demonstrate the proposed method of pH mapping, the progress of extracellular acidosis in tumor-bearing mouse legs was studied. Furthermore, extracellular pH mapping was used to visualize the spatial distribution of acidification in different tumor xenograft mouse models of human-derived pancreatic ductal adenocarcinoma cells. The proposed EPR-based pH mapping method enabled quantitative visualization of regional changes in extracellular pH associated with altered tumor metabolism.


Assuntos
Carcinoma Ductal Pancreático/patologia , Carcinoma de Células Escamosas/patologia , Imageamento Tridimensional , Animais , Espectroscopia de Ressonância de Spin Eletrônica , Humanos , Concentração de Íons de Hidrogênio , Camundongos , Neoplasias Experimentais/patologia
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