Pulmonary fibrosis is a chronic inflammatory disorder marked by fibroblast activation, collagen deposition, thickening of the alveolar septum, and impaired lung function. Profibrotic macrophages play a pivotal role in driving inflammatory responses during the progression of pulmonary fibrosis and have emerged as promising therapeutic targets. Although distinct from classical M1/M2 macrophage phenotypes, profibrotic macrophages across various forms of pulmonary fibrosis exhibit shared transcriptomic profiles associated with fibrogenesis. This review aims to summarize the characteristics, origins, developmental trajectories, distribution, energy metabolism, and epigenetic regulation of profibrotic macrophage populations in different pulmonary fibrosis diseases and animal models. In the context of pulmonary fibrosis, these macrophages engage in robust crosstalk with non-immune cells in the lung—such as fibroblasts and type II alveolar epithelial cells—thereby exacerbating fibrotic processes. Consequently, strategies aimed at depleting profibrotic macrophages or disrupting their detrimental interactions with non-immune cells may show promise as potential therapeutic approaches to slow disease progression, offering new avenues for treatment.
Radiation-induced intestinal injury, a common complication of abdominal/pelvic radiotherapy for cancer patients and accidental irradiation, presents a major clinical challenge due to the lack of effective treatments. This study investigates the radioprotective potential of β-cryptoxanthin, a provitamin A carotenoid known for its antioxidant properties. In vivo, oral β-cryptoxanthin administration alleviated radiation-induced intestinal injury by enhancing the NRF2-mediated antioxidant response, which was confirmed by its lack of efficacy in Nrf2-/- mice. Additionally, it restored radiation-impaired microbiota by increasing beneficial bacterial populations and protective metabolites like short-chain fatty acids (SCFAs), thereby re-establishing a radioprotective gut ecosystem. At the cellular level, β-cryptoxanthin pretreatment significantly improved cell viability and proliferation while reducing reactive oxygen species (ROS), apoptosis, and DNA damage in irradiated MODE-K intestinal epithelial cells. Mechanistically, β-cryptoxanthin activated the AMPK-GSK3β signaling axis, which drove NRF2 nuclear translocation and upregulated NRF2-dependent cytoprotective genes. Knockdown of NRF2 or AMPK abolished the radioprotective effects, confirming the involvement of these pathways. Overall, this study demonstrates that β-cryptoxanthin protects against radiation-induced intestinal injury through dual mechanisms: activating the NRF2-mediated antioxidant response and reprogramming the gut microbiota to restore a radioprotective ecosystem. These findings position β-cryptoxanthin as a promising candidate for clinical radioprotection.
BACKGROUND:Cytokine-based cancer therapies have attracted a great deal of attention in recent years. Unfortunately, resistance to treatment limits the efficacy of these therapeutics. Therefore, the aim of our study was to explore the mechanism of IL-2-based therapy for hepatocellular carcinoma in an attempt to increase the efficiency of this treatment option. METHODS:HepG2 cells were treated with IL-2. Then, siRNA against TZA was used to transfected into HepG2 cells. Cellular apoptosis was measured via MTT assay, TUNEL assay and caspase-3 activity. Cellular proliferation was evaluated via EdU assay and western blotting. Cellular migration was detected via Transwell assay. Mitochondrial function was monitored by mitochondrial potential analysis, ROS staining, immunofluorescence and western blotting. Pathway blocker and activator were used to establish the role of JNK/F-actin/mitochondrial fission signaling pathway in HepG2 cells stress response. RESULTS:Our study found that IL-2 treatment significantly reduced the viability, mobility and proliferation of HepG2 cells in vitro. We also demonstrated that IL-2 treatment was accompanied by an increase in the expression of transcriptional co-activator with PDZ-binding motif (TAZ). Interestingly, genetic ablation of TAZ in the presence of IL-2 further promoted apoptosis, inhibited mobility, and arrested proliferation in HepG2 cells. At the molecular level, IL-2 administration activated excessive mitochondrial fission via the JNK/F-actin pathway; these effects were further enhanced by TAZ deletion. Mechanistically, TAZ knockdown further increased the expression of mitochondrial fission-related proteins such as Drp1, Mff and Fis. The augmented mitochondrial fission stimulated ROS overproduction, mediated redox imbalance, interrupted mitochondrial energy generation, reduced mitochondrial membrane potential, promoted leakage of the pro-apoptotic molecule cyt-c into the nucleus, and initiated caspase-9-related mitochondrial death. Further, we demonstrated that the anti-proliferative and anti-metastatic effects of IL-2 in HepG2 cells were enhanced by TAZ deletion, suggesting that IL-2 sensitizes HepG2 cells to IL-2-based cytokine therapy. However, JNK/F-actin pathway blockade could abrogate the inhibitory effects of TAZ deletion on HepG2 migration, proliferation and survival. CONCLUSIONS:Taken together, our data indicate that the anti-tumor effects of IL-2-based therapies may be enhanced by TAZ deletion in a JNK/F-actin pathway-dependent manner. This finding provides a novel combinatorial therapeutic approach for treating hepatocellular carcinoma that might significantly increase the efficacy of cytokine-based therapies in a clinical setting.
Background Occupational risks remain an important yet underrecognized contributor to the global burden of disease. Understanding long-term trends and regional disparities in occupational health risks is essential for effective prevention. Methods We used data from the Global Burden of Disease Study (GBD) 2021 to estimate Disability-Adjusted Life Years (DALYs) attributable to six major occupational risk factors (occupational carcinogens, asthmagens, noise, ergonomic factors, injuries, and occupational particulate matter, gases, and fumes) across 204 countries and territories from 1990 to 2021. We used joinpoint regression to identify significant trend shifts and average annual trends. Furthermore, we conducted decomposition analyses to identify drivers of change and applied Bayesian age-period-cohort models to project DALYs to 2030. Results were disaggregated by sex, region, and Socio-demographic Index (SDI). Results Between 1990 and 2021, total DALYs attributable to six selected occupational risk factors increased from 73.0 million to 77.2 million, while the global age-standardized DALYs rate declined significantly (-1.72% per year; 95% CI: -1.78 to -1.66). The burden was consistently higher in males and low-SDI regions. Population growth and ageing were the primary drivers of increasing DALYs, while reductions in exposure levels had limited or counterbalancing effects. Occupational injuries and ergonomic factors were the leading contributors in low-SDI settings, whereas carcinogen-related DALYs predominated in high-SDI countries. Notably, the burden from occupational noise continued to rise globally. Inequality analyses revealed persistent disparities, including in high-income regions. Conclusions Although substantial progress has been made in reducing age-standardized rates, occupational risks still contribute meaningfully to global health loss. Region-specific and equity-oriented strategies remain essential to address preventable occupational disease burden, particularly in low-resource settings.
Inulin's health benefits, influenced by its degree of polymerization (DP), are linked to gut microbiota and metabolite modulation. Radiation-induced intestinal injury (RIII), a side effect of abdominal/pelvic radiotherapy, is associated with gut dysbiosis, making microbiota modulation a potential treatment. The study examined three inulin types (DP = 2, 4, 18: Inulin-O, Inulin-M, Inulin-H) in murine RIII models. Short-chain Inulin-O and Inulin-M offered protection, while long-chain Inulin-H, despite its strong microbiota impact, promoted harmful bacteria. Inulin-O mainly affected metabolites, whereas Inulin-M altered microbial structure. In vitro, Inulin-O-derived metabolites promoted MODE-K cell proliferation and reduced radiation-induced ROS, DNA damage, cell cycle arrest, and apoptosis. Flow cytometry analysis indicated that Inulin-M protected mice from radiation-induced T-cell damage. Mechanistically, Inulin-O shielded intestinal cells by modulating gut microbiota for beneficial metabolites, and Inulin-M protected T-cells by targeting altered microbiota. The dose-effect relationship studies demonstrated that Inulin-O exhibited optimal radioprotective effects against RIII at 1 % concentration, while Inulin-M showed a clear dose-dependent effect within the tested concentration range (up to 10 %), achieving maximum protection at the 10 % concentration. These findings suggest that both Inulin-O and Inulin-M have potential for RIII prevention. Although their DP differs only slightly, they display distinct mechanisms of action and markedly different dose-effect characteristics.
Radiation-induced intestinal injury is a common complication of abdominopelvic cancer radiotherapy, often associated with gut bacteriome dysbiosis. However, the involvement of gut virome in this process remains largely underexplored. Here, it was found that radiation disrupted the gut virome, altered the distribution of phages and their bacterial host. Fecal virome transplantation (FVT) from healthy donors ameliorated radiation-induced intestinal damage and promoted stem cell proliferation by enriching phages targeting Salmonella. Conversely, decreased virome load exacerbated intestinal damage, reduced proliferating stem cells, and impaired secretory lineage differentiation. Mechanistically, exacerbated intestinal injury was associated with hyperactivation of RIG-I and Notch signaling in intestinal stem cells, which was absent in RIG-I-deficient mice. Organoids from RIG-I-deficient mice displayed decreased Notch signals and increased regenerative capacity post radiation. These findings shed light on the intricate interplay between gut virome, intestinal injury, and stem cell responses, highlighting potential therapeutic interventions for targeting the virome to mitigate radiation-induced intestinal damage.
Dysregulated autophagy plays a critical role in the pathogenesis of pulmonary fibrosis. The stress protein TRIB3 has been correlated with abnormal autophagy, but its specific contribution to radiation-induced pulmonary fibrosis (RIPF) remains unclear. This study aimed to elucidate the role of TRIB3 in RIPF progression. We conducted RNA-sequencing of rat RIPF lung tissue to analyze the transcriptomic profile and determine gene expression changes in murine with RIPF. We established mouse models with alveolar epithelial type II cells (AEC II)-specific knockdown or overexpression of TRIB3 to elucidate its role in RIPF progression. We utilized mRFP-GFP-LC3 fluorescent reporter cells, nanoparticle tracking analysis, immunofluorescence and immunoprecipitation assays to uncover the underlying mechanisms. TRIB3 expression was elevated in irradiated AEC II. Silencing TRIB3 in AEC II mitigated RIPF in mice, whereas its overexpression exacerbated the condition. Mechanistically, TRIB3 interacted with the LC3-interacting region (LIR) motif and ubiquitin-associated (UBA) domain of sequestosome 1 (SQSTM1), an autophagic receptor protein, thereby inhibiting autophagic flux in AEC II cell line MLE12. This inhibition increased exosome secretion and facilitated crosstalk between MLE12 cells and fibroblasts, ultimately enhancing the proliferation and extracellular matrix production of lung fibroblasts. TRIB3 in AEC II inhibits autophagic flux by interacting with SQSTM1, thereby increasing exosome secretion, which promotes fibroblast proliferation and extracellular matrix production, contributing to RIPF progression.
The use of radiation therapy to treat pelvic and abdominal cancers can lead to the development of either acute or chronic radiation enteropathy. Radiation-induced chronic colonic fibrosis is a common gastrointestinal disorder resulting from the above radiation therapy. In this study, we establish the efficacy of inulin supplements in safeguarding against colonic fibrosis caused by irradiation therapy. Studies have demonstrated that inulin supplements enhance the proliferation of bacteria responsible to produce short-chain fatty acids (SCFAs) and elevate the levels of SCFAs in feces. In a mouse model of chronic radiation enteropathy, the transplantation of gut microbiota and its metabolites from feces of inulin-treated mice were found to reduce colonic fibrosis in validation experiments. Administering inulin-derived metabolites from gut microbiota led to a notable decrease in the expression of genes linked to fibrosis and collagen production in mouse embryonic fibroblast cell line NIH/3T3. In the cell line, inulin-derived metabolites also suppressed the expression of genes linked to the extracellular matrix synthesis pathway. The results indicate a novel and practical approach to safeguarding against chronic radiation-induced colonic fibrosis.
Background: Radiation resistance is the main limitation of the application of radiotherapy. Ionizing radiation (IR) kills cancer cells mainly by causing DNA damage, particularly double-strand breaks (DSBs). Radioresistant cancer cells have developed the robust capability of DNA damage repair to survive IR. Nuclear factor erythroid 2-related factor 2 (NRF2) has been correlated with radiation resistance. We previously reported a novel function of NRF2 as an ATR activator in response to DSBs. However, little is known about the mechanism that how NRF2 regulates DNA damage repair and radiation resistance. Methods: The TCGA database and tissue microarray were used to analyze the correlation between NRF2 and the prognosis of lung cancer patients. The radioresistant lung cancer cells were constructed, and the role of NRF2 in radiation resistance was explored by in vivo and in vitro experiments. Immunoprecipitation, immunofluorescence and extraction of chromatin fractions were used to explore the underlying mechanisms. Results: In this study, the TCGA database and clinical lung cancer samples showed that high expression of NRF2 was associated with poor prognosis in lung cancer patients. We established radioresistant lung cancer cells expressing NRF2 at high levels, which showed increased antioxidant and DNA repair abilities. In addition, we found that NRF2 can be involved in the DNA damage response independently of its antioxidant function. Mechanistically, we demonstrated that NRF2 promoted the phosphorylation of replication protein A 32 (RPA32), and DNA topoisomerase 2-binding protein 1 (TOPBP1) was recruited to DSB sites in an NRF2-dependent manner. Conclusion: This study explored the novel role of NRF2 in promoting radiation resistance by cooperating with RPA32 and TOPBP1 to activate the ATR-CHK1 signaling pathway. In addition, the findings of this study not only provide novel insights into the molecular mechanisms underlying the radiation resistance of lung cancer cells but also validate NRF2 as a potential target for radiotherapy.
A high level of reduced glutathione is a major factor contributing to the radioresistance observed in solid tumors. To address this radioresistance associated with glutathione, a cinnamaldehyde (CA) polymer prodrug, referred to as PDPCA, is fabricated. This prodrug is created by synthesizing a pendent CA prodrug with acetal linkages in a hydrophobic block, forming a self-assembled into a core-shell nanoparticle in aqueous media. Additionally, it encapsulates all-trans retinoic acid (ATRA) for synchronous delivery, resulting in PDPCA@ATRA. The PDPCA@ATRA nanoparticles accumulate reactive oxygen species through both endogenous and exogenous pathways, enhancing ferroptosis by depleting glutathione. This approach demonstrates efficacy in overcoming tumor radioresistance in vivo and in vitro, promoting the ferroptosis, and enhancing the cytotoxic T lymphocyte (CTL) response for lung tumors to anti-PD-1 (αPD-1) immunotherapy. Furthermore, this study reveals that PDPCA@ATRA nanoparticles promote ferroptosis through the NRF2-GPX4 signaling pathway, suggesting the potential for further investigation into the combination of radiotherapy and αPD-1 immune checkpoint inhibitors in cancer treatment.
BACKGROUND:Alveolar epithelial injury and dysfunction are the risk factors for radiation-induced pulmonary fibrosis (RIPF). However, it is not clear about the relationship between RIPF and the small extracellular vesicles (sEV) secreted by irradiated alveolar epithelial cells. Based on the activation of fibroblasts, this study explored the role of sEV derived from alveolar epithelial cells in RIPF and the potential mechanisms. METHODS:Transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and western blotting were used to characterize sEV. Western blotting was used to detect fibrosis-associated proteins. Cell counts and transwell assays were used to evaluate the proliferation and migration ability of fibroblasts. RT-PCR was used to observe the extracellular matrix (ECM) synthesized by fibroblasts, miRNA changes in the sEV were determined by second-generation sequencing. RESULTS:TEM, NTA, and western blotting showed the extracellular vesicles with a double-layer membrane structure of approximately 100 nm in diameter. The sEV derived from irradiated A549, HBEC3-KT, and MLE12 cells upregulated FN1 and alpha-SMA proteins expression in fibroblasts and drove the fibroblast to myofibroblast transition, and the sEV from irradiated mouse bronchoalveolar lavage fluid (BALF) affirmed the same results. In addition, the sEV derived from irradiated alveolar epithelial cells significantly increased the migration ability of fibroblasts and the expression of extracellular matrix proteins such as FN1. The results of miRNA sequencing of sEV in BALF of rats with RIPF showed that the metabolic pathway may be important for miRNA to regulate the activation of fibroblasts. CONCLUSION:The sEV derived from radiated pulmonary epithelial cells promote the activation, migration and extracellular matrix proteins expression of lung fibroblasts; miRNA in sEV may be an important molecular that affects the activation of lung fibroblasts.
l-2-Hydroxyglutarate (l-2-HG) has been regarded as a tumor metabolite, and it plays a crucial role in adaptation of tumor cells to hypoxic conditions. However, the role of l-2-HG in tumor radioresistance and the underlying mechanism have not yet been revealed. Here, we found that l-2-HG exhibited to have radioresistance effect on U87 human glioblastoma cells, which could reduce DNA damage and apoptosis caused by irradiation, promote cell proliferation and migration, and impair G2/M phase arrest. Mechanistically, l-2-HG upregulated the protein level of hypoxia-inducible factor-1α (HIF-1α) and the expression levels of HIF-1α downstream target genes. The knockdown of l-2-hydroxyglutarate dehydrogenase (L2HGDH) gene promoted the tumor growth and proliferation of U87 cells in nude mice by increasing HIF-1α expression level in vivo. In addition, the low expression level of L2HGDH gene was correlated with the short survival of patients with glioma or kidney cancer. In conclusion, our study revealed the role and mechanism of l-2-HG in tumor radioresistance and may provide a new perspective for overcoming tumor radioresistance and broaden our comprehension of the role of metabolites in tumor microenvironment.
Background: Radiation-induced intestinal injuries are common in patients with pelvic or abdominal cancer. However, these injuries are currently not managed effectively. Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have been extensively used in regenerative medicine. However, the results of MSC-EVs in the repair of radiation-induced intestinal damage have been unsatisfactory. We here investigated the nanotherapeutic functions of MSC-EVs in radiation-induced intestinal injury. Methods: We visualized the biodistribution and trend of MSC-EVs through in vivo imaging. A radiationinduced intestinal injury model was constructed, and the therapeutic effect of MSC-EVs was explored through in vivo and in vitro experiments. Immunofluorescence and qRT-PCR assays were conducted to explore the underlying mechanisms. Results: MSC-EVs exhibited a dose-dependent tendency to target radiation-injured intestines while providing spatiotemporal information for the early diagnosis of the injury by quantifying the amount of MSC-EVs in the injured intestines through molecular imaging. Meanwhile, MSC-EVs displayed superior nanotherapeutic functions by alleviating apoptosis, improving angiogenesis, and ameliorating the intestinal inflammatory environment. Moreover, MSC-EVs-derived miRNA-455-5p negatively regulated SOCS3 expression, and the activated downstream Stat3 signaling pathway was involved in the therapeutic efficacy of MSC-EVs in radiation-induced intestinal injuries. Conclusion: MSC-EVs can dose-dependently target radiation-injured intestinal tissues, allow a spatiotemporal diagnosis in different degrees of damage to help guide personalized therapy, offer data injury, and provide cell-free treatment for radiation therapy.
Background The dose–response relationship between cancers and protracted low-dose rate exposure to ionising radiation is still uncertain. This study aims to estimate quantified relationships between low-dose radiation exposures and site-specific solid cancers among Chinese medical X-ray workers. Methods This cohort study included 27 011 individuals who were employed at major hospitals in 24 provinces in China from 1950 to 1980 and had been exposed to X-ray equipment, and a control group of 25 782 physicians who were not exposed to X-ray equipment. Person-years of follow-up were calculated from the year of employment to the date of the first diagnosis of cancer or the end of follow-up, whichever occurred first. All cancers were obtained from medical records during 1950–1995. This study used Poisson regression models to estimate the excess relative risk (ERR) and excess absolute risk (EAR) for incidence of site-specific solid cancers associated with cumulative dose. Results 1643 solid cancers were developed, the most common being lung, liver and stomach cancer. Among X-ray workers, the average cumulative colon dose was 0.084 Gy. We found a positive relationship between cumulative organ-specific dose and liver (ERR/Gy=1.48; 95% CI 0.40 to 2.83), oesophagus (ERR/Gy=18.1; 95% CI 6.25 to 39.1), thyroid (ERR/Gy=2.96; 95% CI 0.44 to 8.18) and non-melanoma skin cancers (ERR/Gy=7.96; 95% CI 2.13 to 23.12). We found no significant relationship between cumulative organ-specific doses and other cancers. Moreover, the results showed a statistically significant EAR for liver, stomach, breast cancer (female), thyroid and non-melanoma skin cancers. Conclusions These findings provided more useful insights into the risks of site-specific cancers from protracted low-dose rate exposure to ionising radiation.
The association between long-term exposure to e-waste and poor health is well established, but how e-waste exposure affects DNA methylation is understudied. In this study, we measured the DNA damage levels and the alternation of DNA methylation in peripheral blood mononuclear cells (PBMCs) collected from a population exposed to e-waste. The concentration of 28 PCB congeners in the blood samples of e-waste recycling workers was elevated than those of the reference group. DNA damage levels were significantly higher than that of samples from the reference group by detecting the SCGE, CA, and CBMN assays. Eventually, we found that the methylation level of 1233 gene loci was changed in the exposure group. Bioinformatic analysis of differential genes revealed that the hypermethylated genes were enriched in cell component movement and regulation of cell function, and hypomethylated genes were involved in the cellular metabolic process. Among the 30 genes we tested, 14 genes showed a negative correlation between methylation level and expression level. Therefore, e-waste exposure potentially increased the levels of DNA damage and alters DNA methylation, which would likely impact human health.
Ionizing radiation (IR) causes a wide variety of DNA lesions, of which DNA double-stranded breaks (DSBs) are the most deleterious. Homologous recombination (HR) is a crucial route responsible for repairing DSBs. RecQ-mediated genome instability protein 1 (RMI1) is a member of an evolutionarily conserved Bloom syndrome complex, which prevents and resolves aberrant recombination products during HR, thereby promoting genome stability. However, little is known about the role of RMI1 in regulating the cellular response to IR. This study aimed to understand the cellular functions and molecular mechanisms by which RMI1 maintains genomic stability after IR exposure. Here, we showed IR upregulated the RMI1 protein level and induced RMI1 relocation to the DNA damage sites. We also demonstrated that the loss of RMI1 in cells resulted in enhanced levels of DNA damage, sustained cell cycle arrest, and impaired HR repair after IR, leading to reduced cell viability and elevated genome instability. Taken together, our results highlighted the direct roles of RMI1 in response to DNA damage induced by IR and implied that RMI1 might be a new genome safeguard molecule to radiation-induced damage.
BACKGROUND:The transmembrane receptor Kremen2 has been reported to participate in the tumorigenesis and metastasis of gastric cancer. However, the role of Kremen2 in non-small cell lung cancer (NSCLC) and the underlying mechanism remain unclear. This study aimed to explore the biological function and regulatory mechanism of Kremen2 in NSCLC.METHODS:The correlation between Kremen2 expression and NSCLC was assessed by analyzing the public database and clinical tissue samples. Colony formation and EdU assays were performed to examine cell proliferation. Transwell and wound healing assays were used to observe cell migration ability. Tumor-bearing nude mice and metastatic tumor models were used to detect the in vivo tumorigenic and metastatic abilities of the NSCLC cells. An immunohistochemical assay was used to detect the expression of proliferation-related proteins in tissues. Western blot, immunoprecipitation and immunofluorescence were conducted to elucidate the Kremen2 regulatory mechanisms in NSCLC.RESULTS:Kremen2 was highly expressed in tumor tissues from NSCLC patients and was positively correlated with a poor patient prognosis. Knockout or knockdown of Kremen2 inhibited cell proliferation and migration ability of NSCLC cells. In vivo knockdown of Kremen2 inhibited the tumorigenicity and number of metastatic nodules of NSCLC cells in nude mice. Mechanistically, Kremen2 interacted with suppressor of cytokine signaling 3 (SOCS3) to maintain the epidermal growth factor receptor (EGFR) protein levels by preventing SOCS3-mediated ubiquitination and degradation of EGFR, which, in turn, promoted activation of the PI3K-AKT and JAK2-STAT3 signaling pathways.CONCLUSIONS:Our study identified Kremen2 as a candidate oncogene in NSCLC and may provide a potential target for NSCLC treatment.
PURPOSE:The aim of this work was to explore the role and mechanism of active DNA demethylase in colorectal cancer (CRC) radiation sensitization and better understand the function of DNA demethylation in tumor radiosensitization. METHODS AND MATERIALS:Tested the effect of ten-eleven translocation 3 (TET3) overexpression on the sensitivity of CRC to radiation therapy through G2/M arrest, apoptosis, and clonogenic suppression. TET3 knockdown HCT 116 and TET3 knockdown LS 180 cell lines were constructed by siRNA technology, and the effect of exogenous knockdown of TET3 on radiation-induced apoptosis, cell cycle arrest, DNA damage, and clone formation in CRC cells were detected. The co-localization of TET3 and small ubiquitin-like modifier 1 (SUMO1), SUMO2/3 was detected by immunofluorescence and cytoplasmic-nuclear extraction, and the interaction between TET3 and SUMO1, SUMO2/3 was detected by a coimmunoprecipitation assay. RESULTS:The malignant phenotype and radiosensitivity of CRC cell lines were favorably linked with TET3 protein and mRNA expression. TET3 is upregulated in 23 of the 27 tumor types investigated, including colon cancer. TET3 was shown to correlate with the CRC pathologic malignancy grade positively. Overexpression of TET3 in CRC cell lines increased radiation-induced apoptosis, G2/M phase arrest, DNA damage, and clonal suppression in vitro. The binding region of TET3 and SUMO2/3 was located at 833-1795 AA except for K1012, K1188, K1397, and K1623. SUMOylation of TET3 increased the stability of the TET3 protein without changing its nuclear localization. CONCLUSIONS:We report the sensitizing role of TET3 protein in the radiation of CRC cells, depending on SUMO1 modification of TET3 at the lysine sites (K479, K758, K1012, K1188, K1397, K1623), in turn stabilizing TET3 expression in the nucleus and subsequently increasing the sensitivity of CRC to radiation therapy. Together, this study highlights the potentially critical role of TET3 SUMOylation in radiation regulation, which may contribute to an enhanced understanding of the relationship between DNA demethylation and radiation therapy.
Objective:To explore the effects of glycosylated nanoparticles on early radiation responses including the generation of reactive oxygen species (ROS), the polarization of pulmonary macrophages, and secretion of inflammatory cytokines in mice lung tissues.Methods:Twenty mice were randomly divided into control group, drug administration group, irradiation group and irradiation + drug administration group. The irradiation group and irradiation + drug administration group were subjected to whole lung irradiation with X-rays. The antioxidant ability of glycosylated nanoparticles was characterized using ROS indicator (CM-H 2DCFDA). The M2 polarization of pulmonary macrophages was detected by flow cytometry and PCR. The mRNA and protein expression levels of inflammatory cytokines were investigated by PCR and ELISA assay, respectively. Results:Compared with the irradiation group, the intensity of ROS fluorescence signals was significantly lower ( t=15.76, P < 0.05), the proportion of M2-type macrophages was significantly higher ( t=2.89, P < 0.05), the expression level of arginase 1 (ARG-1) gene was elevated, and the expression levels of tumour necrosis factor α (TNF-α), interleukin 1β (IL-1β) and interleukin 6 (IL-6) inflammatory factors were significantly reduced ( t=3.32, 2.90, 2.85, 4.55, 2.88, P < 0.05) in the lung tissues of irradiation + treatment group. Conclusions:Glycosylated nanoparticles can effectively scavenge ROS, trigger polarization of M2 macrophage, dampen inflammatory responses, and thus potentially alleviate radiation-induced lung injury.