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1.
Sci Total Environ ; 947: 174628, 2024 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-38992371

RESUMEN

The Tibetan Plateau, a typical high-altitude area, is less affected by human activities such as industrial development, and the external pollution to water sources is extremely low. Then it is also an important source of water samples for exploring the molecular characteristics of precursors in the dissolved organic matter (DOM) of disinfection byproducts (DBPs) in drinking water. Research data on DBPs in drinking water on the Tibet Plateau remains insufficient, leading to uncertainty about DBP contamination in the area. This study explores the formation potential of 35 typical DBPs, including 6 trihalomethanes (THMs), 9 haloacetic acids (HAAs), 2 halogenated ketones (HKs), 9 nitrosamines (NAs), and 9 aromatic DBPs, during chlorination and chloramination of typical source water samples in the Tibet Plateau of China. Moreover, in order to further investigate the characteristics of the generation of DBPs, the molecular composition of DOM in the collected water samples was characterized by Fourier transform ion cyclotron resonance mass spectrometry. The findings reveal that, for chlorination and chloramination, the average concentration of the five classes of DBPs was ranked as follows (chlorination, chloramination): HAAs (268.1 µg/L, 54.2 µg/L) > THMs (44.0 µg/L, 2.0 µg/L) > HKs (0.7 µg/L, 1.8 µg/L) > NAs (26.5 ng/L, 74.6 ng/L) > Aromatics (20.4 ng/L, 19.5 ng/L). The dominant compounds in THMs, HAAs, and NAs are trichloromethane, dichloroacetic acid, trichloroacetic acid, and nitrosopyrrolidine, respectively. This study highlights a significant positive correlation between DBP generation and UV254, SUV254, and the double bond equivalents of DOM in the source water. It systematically elucidates DOM molecular composition characteristics and DBP formation potential in high-altitude water sources, shedding light on key factors influencing DBP generation at the molecular level in high-altitude areas.

2.
Biol Chem ; 405(6): 407-415, 2024 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-38598859

RESUMEN

Radiation-induced skin injury is a common side effect of radiotherapy, but there are few therapeutic drugs available for prevention or treatment. In this study, we demonstrate that 18ß-Glycyrrhetinic acid (18ß-GA), a bioactive component derived from Glycyrrhiza glabra, substantially reduces the accumulation of reactive oxygen species (ROS) and inhibits apoptosis in HaCaT cells after ionizing radiation (IR), thereby mitigating radiation-induced skin injury. Mechanistically, 18ß-GA promotes the nuclear import of Nrf2, leading to activation of the Nrf2/HO-1 signaling pathway in response to IR. Importantly, Nrf2 silencing increases cell apoptosis and reverse the protective effect of 18ß-GA on radiation-induced skin injury. Furthermore, 18ß-GA preserves skin tissue structure after irradiation, inhibits inflammatory cell infiltration, and alleviates radiation dermatitis. In conclusion, our results suggest that 18ß-GA reduces intracellular ROS production and apoptosis by activating the Nrf2/HO-1 signaling pathway, leading to amelioration of radiation dermatitis.


Asunto(s)
Ácido Glicirretínico , Hemo-Oxigenasa 1 , Factor 2 Relacionado con NF-E2 , Especies Reactivas de Oxígeno , Transducción de Señal , Ácido Glicirretínico/farmacología , Ácido Glicirretínico/análogos & derivados , Factor 2 Relacionado con NF-E2/metabolismo , Humanos , Transducción de Señal/efectos de los fármacos , Hemo-Oxigenasa 1/metabolismo , Animales , Especies Reactivas de Oxígeno/metabolismo , Piel/efectos de los fármacos , Piel/efectos de la radiación , Piel/metabolismo , Piel/patología , Apoptosis/efectos de los fármacos , Ratones
3.
J Agric Food Chem ; 72(13): 7021-7032, 2024 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-38501582

RESUMEN

Lakes and reservoirs worldwide are experiencing a growing problem with harmful cyanobacterial blooms (HCBs), which have significant implications for ecosystem health and water quality. Algaecide is an effective way to control HCBs effectively. In this study, we applied an active substructure splicing strategy for rapid discovery of algicides. Through this strategy, we first optimized the structure of the lead compound S5, designed and synthesized three series of thioacetamide derivatives (series A, B, C), and then evaluated their algicidal activities. Finally, compound A3 with excellent performance was found, which accelerated the process of discovering and developing new algicides. The biological activity assay data showed that A3 had a significant inhibitory effect on M. aeruginosa. FACHB905 (EC50 = 0.46 µM) and Synechocystis sp. PCC6803 (EC50 = 0.95 µM), which was better than the commercial algicide prometryn (M. aeruginosa. FACHB905, EC50 = 6.52 µM; Synechocystis sp. PCC6803, EC50 = 4.64 µM) as well as better than lead compound S5 (M. aeruginosa. FACHB905, EC50 = 8.80 µM; Synechocystis sp. PCC6803, EC50 = 7.70 µM). The relationship between the surface electrostatic potential, chemical reactivity, and global electrophilicity of the compounds and their activities was discussed by density functional theory (DFT). Physiological and biochemical studies have shown that A3 might affect the photosynthesis pathway and antioxidant system in cyanobacteria, resulting in the morphological changes of cyanobacterial cells. Our work demonstrated that A3 might be a promising candidate for the development of novel algicides and provided a new active skeleton for the development of subsequent chemical algicides.


Asunto(s)
Herbicidas , Synechocystis , Tioacetamida , Ecosistema , Herbicidas/química
4.
Blood ; 143(2): 124-138, 2024 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-37748139

RESUMEN

ABSTRACT: Aged hematopoietic stem cells (HSCs) exhibit compromised reconstitution capacity. The molecular mechanisms behind this phenomenon are not fully understood. Here, we observed that the expression of FUS is increased in aged HSCs, and enforced FUS recapitulates the phenotype of aged HSCs through arginine-glycine-glycine-mediated aberrant FUS phase transition. By using Fus-gfp mice, we observed that FUShigh HSCs exhibit compromised FUS mobility and resemble aged HSCs both functionally and transcriptionally. The percentage of FUShigh HSCs is increased upon physiological aging and replication stress, and FUSlow HSCs of aged mice exhibit youthful function. Mechanistically, FUShigh HSCs exhibit a different global chromatin organization compared with FUSlow HSCs, which is observed in aged HSCs. Many topologically associating domains (TADs) are merged in aged HSCs because of the compromised binding of CCCTC-binding factor with chromatin, which is invoked by aberrant FUS condensates. It is notable that the transcriptional alteration between FUShigh and FUSlow HSCs originates from the merged TADs and is enriched in HSC aging-related genes. Collectively, this study reveals for the first time that aberrant FUS mobility promotes HSC aging by altering chromatin structure.


Asunto(s)
Envejecimiento , Células Madre Hematopoyéticas , Ratones , Animales , Envejecimiento/fisiología , Fenotipo , Células Madre Hematopoyéticas/metabolismo , Cromatina/metabolismo , Glicina/metabolismo
5.
Biochem Biophys Res Commun ; 681: 144-151, 2023 11 12.
Artículo en Inglés | MEDLINE | ID: mdl-37774572

RESUMEN

Low-intensity ultrasound can be applied for medical imaging and disease treatment in clinical and experimental studies. However, the biological effects of ultrasound on blood vessels, especially endothelial cells (ECs) are still unclear. In this study, the laws of endothelial cytoskeleton changes under ultrasound induction are investigated. ECs are exposed to low-intensity ultrasound, and the cytoskeletal morphology is analyzed by a filamentous (F)-actin staining technique. We further analyze the characteristics of cytoskeleton rupture using indirect immunofluorescence techniques and cytoskeleton electron microscopy. Finally, the biological effects induced by ultrasound at the tissue level are investigated in an ex vivo blood-vessel model. Significant changes in cytoskeletal structure are detected when induced by ultrasound, including cytoskeletal rupture, blebbing and apoptosis. Moreover, a temporal threshold of ECs injury under different ultrasonic intensities is established. This study illustrates a pattern of significant changes in the cytoskeletal structure of ECs induced by ultrasound. The finding serves as a guide for selecting a safe threshold for clinical ultrasound applications.


Asunto(s)
Citoesqueleto , Células Endoteliales , Actinas , Citoesqueleto de Actina , Microtúbulos
7.
Stem Cells ; 40(12): 1094-1106, 2022 12 31.
Artículo en Inglés | MEDLINE | ID: mdl-36087098

RESUMEN

Long noncoding RNAs (lncRNAs) emerge as important orchestrators of biological processes in embryonic stem cells (ESCs). LncRNA Lx8-SINE B2 was recently identified as an ESC-specific lncRNA that marks pluripotency. Here, we studied the function of lncRNA Lx8-SINE B2 in ESCs. Depletion of Lx8-SINE B2 disrupted ESC proliferation, repressed the expression of pluripotency genes, activated differentiation genes, and inhibited reprogramming to induced pluripotent stem cells. The reduction of the colony formation ability of ESCs upon Lx8-SINE B2 knockdown was accompanied by the elongation of the G1 phase and the shortening of the S phase. Transcriptome analysis revealed that Lx8-SINE B2 deficiency affected multiple metabolic pathways, particularly glycolysis. Mechanistically, Lx8-SINE B2 functions as a cytoplasmic lncRNA and interacts with the glycolytic enzyme Eno1 as shown by RNA pull-down and RNA localization analysis. Lx8-SINE B2 and Eno1 interact with and regulate each other's expression, hence promoting the expression of metabolic genes and influencing glycolysis. In conclusion, we have identified lncRNA Lx8-SINE B2 as a novel regulator of ESC proliferation, cell cycle, and metabolism through working with Eno1.


Asunto(s)
Células Madre Pluripotentes Inducidas , ARN Largo no Codificante , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Células Madre Embrionarias/metabolismo , Diferenciación Celular/genética , Perfilación de la Expresión Génica , Células Madre Pluripotentes Inducidas/metabolismo
8.
J Gastrointest Oncol ; 13(3): 1367-1375, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35837188

RESUMEN

Background: Repeated transcatheter arterial chemoembolization (TACE) could cause ischemia of the tumor tissue and increases production of angiogenic factors in patients with hepatocellular carcinoma (HCC). Lenvatinib can inhibit the expression of angiogenic factors induced by ischemia after TACE and reduce angiogenesis and tumor recurrence. TACE-lenvatinib sequential therapy may improve clinical outcomes. There have been few investigations of TACE-lenvatinib sequential therapy for the treatment of unresectable HCC. We aimed to evaluate the efficacy and safety of TACE-lenvatinib sequential therapy for unresectable HCC. Methods: From May 2018 to May 2021, 53 consecutive patients who underwent TACE-lenvatinib sequential therapy were retrospectively reviewed. Of these, 30 patients who met the inclusion criteria were selected. Lenvatinib treatment started within 1 or 2 weeks after TACE at a dose of 8 or 12 mg once daily. Treatment response was assessed using dynamic magnetic resonance imaging (MRI) according to the modified response evaluation criteria in solid tumor (mRECIST). Blood tests were also performed at every response evaluation. Patients with complete response (CR) or partial response (PR) and stable disease (SD) received continuous lenvatinib therapy, and patients with progressive disease (PD) received repeated TACE. The progression-free survival (PFS), overall survival (OS), objective response rate (ORR), disease control rate (DCR), and adverse events (AEs) were calculated. Statistical analysis was performed using the Kaplan-Meier method. Results: The median age was 58.5±9.1 years, and 16.7% (5/30) of patients were female. A total of 12 patients were categorized as Barcelona Clinic Liver Cancer (BCLC) Stage B and 18 were BCLC Stage C. The mean follow-up time was 15.7 months. The ORR was 76.7% (23/30), and the DCR was 96.7% (29/30). The median PFS was 6.1 months, and the median OS was 20.7 months. The most common lenvatinib-related AE was rash, and the most common TACE-related AE was elevated aspartate aminotransferase (AST). No treatment-related mortality was observed. Conclusions: From our findings, TACE-lenvatinib sequential therapy may prolong OS and PFS in patients with unresectable HCC, and the side effects are acceptable. The efficacy and safety of the sequential therapy should be confirmed in multiple center randomized controlled trials (RCTs) with a large sample and sufficient follow-up period.

9.
J Gastrointest Oncol ; 13(2): 780-786, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35557575

RESUMEN

Background: The efficacy of transarterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) with portal vein tumor thrombus (PVTT) is limited. There are insufficient data on TACE-lenvatinib sequential therapy for HCC with PVTT. We aimed to assess the efficacy and safety of TACE-lenvatinib sequential therapy for the treatment of HCC and PVTT. Methods: We retrospectively reviewed 12 consecutive patients with HCC and PVTT who underwent TACE-lenvatinib sequential therapy between July 2018 and May 2021. Lenvatinib treatment was started 1 week after TACE at a dose of 8 or 12 mg daily depending on the patient weight. Follow-up examinations were performed at 4 week and then every 8 weeks after the first TACE procedure. Overall survival (OS), progression-free survival (PFS), objective response rate (ORR), disease control rate (DCR) and adverse events (AEs) were calculated. Survival curves of PFS and OS were estimated using the Kaplan-Meier method. Results: The median OS and PFS were 16.9 and 6.15 months, respectively. The ORR and DCR were 75% and 91.7%, respectively. The most common lenvatinib-related AE was hypertension (33.3%), and the most common TACE-related AE was elevated liver enzymes (100%). No treatment-related deaths or grade 4 events were observed. Conclusions: TACE-lenvatinib sequential therapy may be safe and well tolerated, and may improve OS and PFS for HCC patients with PVTT. Further randomized controlled trials with larger cohorts are needed to confirm its efficacy and safety.

10.
Cell Stem Cell ; 29(6): 990-1005.e10, 2022 06 02.
Artículo en Inglés | MEDLINE | ID: mdl-35613617

RESUMEN

The young circulatory milieu capable of delaying aging in individual tissues is of interest as rejuvenation strategies, but how it achieves cellular- and systemic-level effects has remained unclear. Here, we constructed a single-cell transcriptomic atlas across aged tissues/organs and their rejuvenation in heterochronic parabiosis (HP), a classical model to study systemic aging. In general, HP rejuvenated adult stem cells and their niches across tissues. In particular, we identified hematopoietic stem and progenitor cells (HSPCs) as one of the most responsive cell types to young blood exposure, from which a continuum of cell state changes across the hematopoietic and immune system emanated, through the restoration of a youthful transcriptional regulatory program and cytokine-mediated cell-cell communications in HSPCs. Moreover, the reintroduction of the identified rejuvenating factors alleviated age-associated lymphopoiesis decline. Overall, we provide comprehensive frameworks to explore aging and rejuvenating trajectories at single-cell resolution and revealed cellular and molecular programs that instruct systemic revitalization by blood-borne factors.


Asunto(s)
Parabiosis , Rejuvenecimiento , Citocinas , Células Madre Hematopoyéticas
11.
Acta Pharm Sin B ; 12(2): 678-691, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35256939

RESUMEN

Aging-elevated DNMT3A R882H-driven clonal hematopoiesis (CH) is a risk factor for myeloid malignancies remission and overall survival. Although some studies were conducted to investigate this phenomenon, the exact mechanism is still under debate. In this study, we observed that DNMT3A R878H bone marrow cells (human allele: DNMT3A R882H) displayed enhanced reconstitution capacity in aged bone marrow milieu and upon inflammatory insult. DNMT3A R878H protects hematopoietic stem and progenitor cells from the damage induced by chronic inflammation, especially TNFα insults. Mechanistically, we identified that RIPK1-RIPK3-MLKL-mediated necroptosis signaling was compromised in R878H cells in response to proliferation stress and TNFα insults. Briefly, we elucidated the molecular mechanism driving DNMT3A R878H-based clonal hematopoiesis, which raises clinical value for treating DNMT3A R882H-driven clonal hematopoiesis and myeloid malignancies with aging.

14.
Sci Total Environ ; 805: 150286, 2022 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-34537692

RESUMEN

Due to the unfavorable soil conditions and water resources, the cropland use pattern in the farming-pastoral ecotone in northern China is complex. The program named "Grain for Green" has accelerated the cropland change. However, the complex cropland and retired cropland are challenging to monitor with remote sensing due to their spatially dispersed and easily confused with spectrally similar land use classes such as nature grasslands and non-cropped fields. Taking farming-pastoral ecotone in the northern foot of the Yinshan Mountains as a case study, we explored a classification approach for complex cropland and retired cropland, which was introduced as a specific land use class by using multi-temporal Landsat TM and OLI images with Google Earth Engine. During 1990-2000, cropland increased with a sharper growth and increased with a slower growth from 2001 to 2010, and then decreased significantly from 2011 to 2019, to lead the cropland area in 2019 was smaller than an area in 1990. We analyzed the spatiotemporal trajectories of retired cropland in 2019 using the Land Use Change Trajectory method to evaluate its source. In our finding, approximately 77% of retired cropland was labelled as cropland before 2019; albeit, not all retired cropland was converted from cropland. Moreover, we qualitatively assessed the vegetation dynamics in the study area by utilizing the long-term NDVI-mean value to reveal that vegetation coverage has shown a continuously increasing trend. It is related to the decline of cropland and the increase of retired cropland at the same rate. Our results highlighted that the "Grain for Green" program had led the vegetation restoration in the farming-pastoral ecotone. Our approach for monitoring cropland and retired cropland can improve the understanding of the driving factors and consequences of these critical land use change trajectories.


Asunto(s)
Agricultura , Suelo , China , Grano Comestible , Granjas
15.
Cell Death Discov ; 7(1): 297, 2021 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-34663800

RESUMEN

DNA (cytosine-5)-methyltransferase 3A (DNMT3A) mutations occur in ~20% of de novo acute myeloid leukemia (AML) patients, and >50% of these mutations in AML samples are heterozygous missense alterations within the methyltransferase domain at residue R882. DNMT3A R882 mutations in AML patients promote resistance to anthracycline chemotherapy and drive relapse. In this study, we performed high-throughput screening and identified that oridonin, an ent-kaurene diterpenoid extracted from the Chinese herb Rabdosia rubescens, inhibits DNMT3A R882 mutant leukemic cells at a low-micromolar concentration (IC50 = 2.1 µM) by activating both RIPK1-Caspase-8-Caspase-3-mediated apoptosis and RIPK1-RIPK3-MLKL-mediated necroptosis. The inhibitory effect of oridonin against DNMT3A R882 mutant leukemia cells can also be observed in vivo. Furthermore, oridonin inhibits clonal hematopoiesis of hematopoietic stem cells (HSCs) with Dnmt3a R878H mutation comparing to normal HSCs by inducing apoptosis and necroptosis. Overall, oridonin is a potential and promising drug candidate or lead compound targeting DNMT3A R882 mutation-driven clonal hematopoiesis and leukemia.

16.
Oncol Lett ; 21(5): 409, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33841570

RESUMEN

Liver cancer is one of the most common malignant tumors with no available satisfactory treatment. The aim of the present study was to investigate the anti-tumor effect of an irradiated hepatocellular carcinoma (HCC) whole-cell vaccine and its underlying mechanisms. Hepa1-6 and H22 HCC cell lines were irradiated in preparation for whole-cell vaccine production. Subsequently, two HCC tumor-bearing mouse models were created by injecting these Hepa1-6 and H22 cells into the abdominal skin of C57BL/6 and ICR mice, respectively. The mice were immunized with the corresponding whole-cell vaccine the next day, and then once a week until the end of the experimental period. Tumor growth, blood T helper (Th)9 cells and plasma interleukin (IL)-9 levels were monitored during the immunization period. Th9 cells were also induced by in vitro co-culture of the whole-cell vaccine with lymphocytes from the spleen and lymph nodes of the corresponding mice. Alterations of gene expression in transcription factor (TF) were determined by reverse transcription-quantitative PCR, and Th9 cells were detected using flow cytometry. The whole-cell vaccine effectively suppressed HCC tumor growth, as indicated by slower tumor growth and a smaller tumor size in the immunized group compared with the control. The percentage of blood Th9 cells and the concentration of plasma IL-9 were significantly increased in the immunized group. The whole-cell vaccine also induced Th9 cell differentiation and upregulated the expression of TFs PU.1, interferon regulatory factor 4 and basic leucine zipper transcriptional factor ATF-like. These results suggest that the irradiated HCC whole-cell vaccine inhibited tumor growth by increasing Th9 cell numbers in HCC mice.

17.
Indoor Air ; 31(4): 926-957, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33896039

RESUMEN

We reviewed 47 documents published 1967-2019 that reported measurements of volatile organic compounds (VOCs) on commercial aircraft. We compared the measurements with the air quality standards and guidelines for aircraft cabins and in some cases buildings. Average levels of VOCs for which limits exist were lower than the permissible levels except for benzene with average concentration at 5.9 ± 5.5 µg/m3 . Toluene, benzene, ethylbenzene, formaldehyde, acetaldehyde, limonene, nonanal, hexanal, decanal, octanal, acetic acid, acetone, ethanol, butanal, acrolein, isoprene and menthol were the most frequently measured compounds. The concentrations of semi-volatile organic compounds (SVOCs) and other contaminants did not exceed standards and guidelines in buildings except for the average NO2 concentration at 12 ppb. Although the focus was on VOCs, we also retrieved the data on other parameters characterizing cabin environment. Ozone concentration averaged 38 ppb below the upper limit recommended for aircraft. The outdoor air supply rate ranged from 1.7 to 39.5 L/s per person and averaged 6.0 ± 0.8 L/s/p (median 5.8 L/s/p), higher than the minimum level recommended for commercial aircraft. Carbon dioxide concentration averaged 1315 ± 232 ppm, lower than what is permitted in aircraft and close to what is permitted in buildings. Measured temperatures averaged 23.5 ± 0.8°C and were generally within the ranges recommended for avoiding thermal discomfort. Relative humidity averaged 16% ± 5%, lower than what is recommended in buildings.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire Interior , Contaminantes Ambientales , Ozono , Contaminantes Atmosféricos/análisis , Contaminación del Aire Interior/análisis , Aeronaves , Formaldehído/análisis , Humanos
18.
Spectrochim Acta A Mol Biomol Spectrosc ; 250: 119363, 2021 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-33422878

RESUMEN

Graphitic carbon nitride (g-C3N4) has been shown as a promising visible-light photosensitizer for photodynamic therapy (PDT) application. Nevertheless, its therapeutic efficiency is limited by the low efficiency of visible-light utilization. To overcome this issue, 3-amino-1,2,4-triazole-derived graphitic carbon nitride nanosheets (g-C3N5 NSs) are prepared for PDT application. The addition of nitrogen-rich triazole group into the g-C3N4 motif significantly makes the light absorption of g-C3N5 NSs red-shift with the band gap down to 1.95 eV, corresponding to a absorption edge at a wavelength of 636 nm. g-C3N5 NSs generate superoxide anion radicals (O2•-) and singlet oxygen (1O2) under the irradiation of a low-intensity white light emitting diode. Owing to the high efficiency of visible-light utilization, g-C3N5 NSs show about 9.5 fold photocatalytic activity of g-C3N4 NSs. In vitro anticancer studies based on the results of CCK-8 assay, Calcein-AM/PI cell-survival assay and photo-induced intracellular ROS level analysis in living HeLa cells demonstrate the potential of g-C3N5 NSs as a low-toxic and biocompatible high-efficient photosensitizer for PDT.


Asunto(s)
Fotoquimioterapia , Amitrol (Herbicida) , Grafito , Células HeLa , Humanos , Compuestos de Nitrógeno , Triazoles
20.
Front Oncol ; 10: 4, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32117702

RESUMEN

Background: Stereotactic radiotherapy treats hepatocellular carcinoma (HCC) at different stages effectively and safely. Besides its direct killing of cancer cells, radiotherapy stimulates host immunity against hepatoma. However, the role of myeloid-derived suppressor cells (MDSCs) in on-target and off-target anti-HCC effects induced by hypofractionated irradiation (IR) is unclear. Methods and Materials: Hepa1-6 and H22 allogeneic transplanted tumors on hind limbs of C57BL/6 and Institute of Cancer Research (ICR) mice, respectively, were irradiated with 0, 2.5, 4, 6, or 8 Gy/fraction until the total dose reached 40 Gy. The off-target effect induced by the IR was investigated by subsequently inoculating the same HCC cells subcutaneously on the abdomen. MDSCs in peripheral blood and tumor tissues were measured by flow cytometry or immunofluorescence microscopy analysis. IL-6, regulated on activation normal T cell expressed and secreted (RANTES), and granulocyte colony-stimulating factor (G-CSF) in irradiated mouse plasma and hepatoma cell cultures were measured with ELISA kits. Conditioned media (CM) from irradiated HCC cell cultures on bone marrow cell differentiation and MDSC proliferation were examined by co-culture and flow cytometry. Results: Our study showed that the IR of primarily inoculated HCC on hind limbs created an "in situ tumor vaccine" and triggered the antitumor immunity. The immunity was capable of suppressing the growth of the same type of HCC subcutaneously implanted on the abdomen, accompanied with reduced MDSCs in both blood and tumors. The decreased MDSCs were associated with low plasma levels of IL-6, RANTES, and G-CSF. The cytokines IL-6 and RANTES in the CM were lower in the high single IR dose group than in the control groups, but G-CSF was higher. The CM from high single-dose IR-Hepa1-6 cell culture reduced the differentiation of C57BL/6 mouse bone marrow cells into MDSCs, whereas CM from high single-dose IR-H22 cells reduced the proliferation of MDSCs, which might be due to the decreased p-STAT3 in bone marrow cells. Conclusions: The hypofractionated IR on transplanted tumors at the primary location exerted a strong antitumor effect on the same tumor at a different location (off target). This abscopal effect is most likely through the reduction of MDSCs and decrease of IL-6, RANTES, and G-CSF.

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