OBJECTIVE: To investigate the effect of irradiation dose rate of ⁶⁰Co γ-ray on hematopoietic and immune cells in total body irradiation (TBI) mice. METHODS: After TBI with 8 Gy ⁶⁰Co γ-ray at three irradiation dose rates of 0.027, 0.256 and 0.597 Gy/min, the survival and change of body weight of C57BL/6J mice were observed within 30 days. The peripheral blood parameters were examined at each time point within 30 days post-irradiation. The hematopoietic stem/progenitor cell counts of mice were examined on the 10^th and 30^th day post-irradiation by flow cytometry, as well as the proportions of immune cells in peripheral blood, bone marrow and spleen of mice on the 30^th day post-irradiation. RESULTS: After TBI with 8 Gy ⁶⁰Co γ-ray, the 30-day survival rate of high dose-rate group was 0, which was significantly lower than 90% of medium dose-rate group and 100% of low dose-rate group (both P < 0.001). The peripheral blood parameters of all three groups showed a sharp decline → low value → gradually recovering trend. The count of white blood cell, neutrophil, lymphocyte, red blood cell, platelet and hemoglobin level in the high dose-rate and medium dose-rate groups were significantly lower than those in the low dose-rate group on day 7-18 post-irradiation (all P < 0.05), but there were no significant differences between the high dose-rate and medium dose-rate groups (P >0.05). On the 10^th day after irradiation, the proportion and number of bone marrow hematopoietic stem/progenitor cells (including LK, LSK, LT-HSC, ST-HSC, and MPP cells) in the low dose-rate and medium dose-rate groups were significantly decreased compared to those in the normal group (all P < 0.05), but there were no significant differences between the two groups (P >0.05). On the 30^th day after irradiation, LSK, LT-HSC, ST-HSC and MPP cells in the low dose-rate group recovered to normal levels, while those in the medium dose-rate group were still significantly lower than those in the low dose-rate group (all P < 0.001). The results of bone marrow and peripheral immune cell tests on the 30^th day after irradiation showed that the ratios of T and B lymphocytes in the low dose-rate and medium dose-rate groups were reduced compared to that in the normal group (both P < 0.05), while the ratio of neutrophils was increased (P < 0.01). The trend of changes in the spleen and peripheral blood was consistent. CONCLUSION The degree of hematopoietic and immune cell damage in mice after TBI with 8 Gy ⁶⁰Co γ-ray is related to the dose rate, and low dose-rate irradiation can reduce the damage in the animal model. Therefore, choosing the appropriate dose rate of irradiation is a key factor in establishing an objective and reliable experimental animal model of irradiation.
Animals ; Mice ; Whole-Body Irradiation ; Gamma Rays ; Mice, Inbred C57BL ; Hematopoietic Stem Cells/radiation effects* ; Cobalt Radioisotopes ; Dose-Response Relationship, Radiation ; Male

Objective:To explore the correlation between ferroptosis-related proteins SLC7A11, GPX4, ACSL4 and the radiosensitivity and prognosis of nasopharyngeal carcinoma. And to investigate the potential of these proteins as molecular markers for predicting the radiosensitivity of nasopharyngeal carcinoma. Methods: A retrospective analysis was conducted on 52 cases of nasopharyngeal carcinoma （nasopharyngeal carcinoma group） and 20 cases of chronic nasopharyngiti s（control group）. The relevant clinical data were reviewed, and paraffin-embedded tissue blocks were collected for study. The expressions of SLC7A11, GPX4, and ACSL4 in pathological specimens were detected by immunohistochemical staining. The expression differences of ferroptosis-related proteins between the nasopharyngeal carcinoma group and the control group were analyzed. The nasopharyngeal carcinoma group was further divided based on the protein expression levels into high and low expression subgroups for SLC7A11, GPX4, and ACSL4. Subsequently, a differential analysis of clinical data and survival analysis was conducted for each of these subgroups. Finally, logistic regression analysis was performed to identify the factors influencing radiotherapy resistance in nasopharyngeal carcinoma. Results:①The differential analysis revealed that, compared to the control group, the nasopharyngeal carcinoma group exhibited significantly higher expression of SLC7A11 and GPX4, and lower expression of ACSL4 （P<0.05）. ②Notably, the proportion of patients displaying radioresistance was higher in the SLC7A11 and GPX4 high expression groups compared to their respective low expression groups （P<0.05）. However, the proportion of radioresistance in the ACSL4 high expression group was lower than that in the ACSL4 low expression group （P<0.05）. Survival analysis indicated that the 5-year overall survival rate was lower in the SLC7A11 and GPX4 high expression groups compared to their respective low expression groups（P<0.05）. However, the 5-year overall survival rate of the ACSL4 high expression group was higher than that of the ACSL4 low expression group（P<0.05）. ③logistic regression analysis showed that SLC7A11 and GPX4 was an independent risk factor for radioresistance in patients with nasopharyngeal carcinoma（P<0.05）. Conclusion:Nasopharyngeal carcinoma tissues over-express SLC7A11, GPX4, and under-express ACSL4. Over-expression of SLC7A11 and GPX4 are independent risk factors for radioresistance in patients with nasopharyngeal carcinoma. The inhibition of ferroptosis may be related to the occurrence, progression and radioresistance of nasopharyngeal carcinoma. Detection of the expression of SLC7A11, GPX4, and ACSL4 has guiding significance for the evaluation of radiosensitivity and prognosis of patients with nasopharyngeal carcinoma.
Humans ; Nasopharyngeal Carcinoma/radiotherapy* ; Nasopharyngeal Neoplasms/pathology* ; Coenzyme A Ligases/metabolism* ; Radiation Tolerance ; Phospholipid Hydroperoxide Glutathione Peroxidase ; Amino Acid Transport System y+/metabolism* ; Prognosis ; Long-Chain-Fatty-Acid-CoA Ligase ; Retrospective Studies ; Ferroptosis ; Male ; Female ; Middle Aged

Preoperative neoadjuvant chemoradiotherapy, combined with total mesorectal excision, has become the standard treatment for advanced localized rectal cancer (RC). However, the biological complexity and heterogeneity of tumors may contribute to cancer recurrence and metastasis in patients with radiotherapy-resistant RC. The identification of factors leading to radioresistance and markers of radiosensitivity is critical to identify responsive patients and improve radiotherapy outcomes. MicroRNAs (miRNAs) are small, endogenous, and noncoding RNAs that affect various cellular and molecular targets. miRNAs have been shown to play important roles in multiple biological processes associated with RC. In this review, we summarized the signaling pathways of miRNAs, including apoptosis, autophagy, the cell cycle, DNA damage repair, proliferation, and metastasis during radiotherapy in patients with RC. Also, we evaluated the potential role of miRNAs as radiotherapeutic biomarkers for RC.
Humans ; MicroRNAs/metabolism* ; Neoplasm Recurrence, Local ; Rectal Neoplasms/pathology* ; Neoadjuvant Therapy ; Radiation Tolerance/genetics*

Objective: To determine the effect of tumor metastasis-associated gene 1 (MTA1) on the sensitivity of HeLa cells to radiotherapy, and to clarify its molecular mechanism. Methods: The transcriptome differences between MTA1 knocked down Hela cells and control cells were analyzed, and the differentially expressed genes (DEGs) was used to perform Gene-Set Enrichment Analysis (GSEA) and Gene Ontology (GO) cluster analysis. Flow cytometry was used to detect apoptosis in MTA1-overexpressed HeLa cells and control cells before and after 10 Gy X-ray irradiation. Cloning formation assay and real-time cellular analysis (RTCA) were used to monitor the cell proliferation before and after 2 Gy X-ray irradiation. To dissect the underlying molecular mechanisms of MTA1 affecting the sensitivity of radiotherapy, the proteins encoded by the DEGs were selected to construct a protein-protein interaction network, the expression of γ-H2AX was detected by immunofluorescence assay, and the expression levels of γ-H2AX, β-CHK2, PARP and cleaved caspase 3 were measured by western blot. Results: By transcriptome sequencing analysis, we obtained 649 DEGs, of which 402 genes were up-regulated in MTA1 knockdown HeLa cells and 247 genes were down-regulated. GSEA results showed that DEGs associated with MTA1 were significantly enriched in cellular responses to DNA damage repair processes. The results of flow cytometry showed that the apoptosis rate of MTA1 over-expression group (15.67±0.81)% after 10 Gy X-ray irradiation was significantly lower than that of the control group [(40.27±2.73)%, P<0.001]. After 2 Gy X-ray irradiation, the proliferation capacity of HeLa cells overexpressing MTA1 was higher than that of control cells (P=0.024). The numbers of colon in MTA1 over-expression group before and after 2 Gy X-ray irradiation were (176±7) and (137±7) respectively, higher than (134±4) and (75±4) in control HeLa cells (P<0.05). The results of immunofluorescence assay showed that there was no significant expression of γ-H2AX in MTA1 overexpressed and control HeLa cells without X-ray irradiation. Western blot results showed that the expression level of β-CHK2 in MTA1-overexpressing HeLa cells (1.04±0.06) was higher than that in control HeLa cells (0.58±0.25, P=0.036) after 10 Gy X-ray irradiation. The expression levels of γ-H2AX, PARP, and cleaved caspase 3 were 0.52±0.13, 0.52±0.22, and 0.63±0.18, respectively, in HeLa cells overexpressing MTA1, which were lower than 0.87±0.06, 0.78±0.12 and 0.90±0.12 in control cells (P>0.05). Conclusions: This study showed that MTA1 is significantly associated with radiosensitivity in cervical cancer HeLa cells. MTA1 over-expression obviously reduces the sensitivity of cervical cancer cells to X-ray irradiation. Mechanism studies initially indicate that MTA1 reduces the radiosensitivity of cervical cancer cells by inhibiting cleaved caspase 3 to suppress apoptosis and increasing β-CHK2 to promote DNA repair.
Apoptosis/genetics* ; Caspase 3/metabolism* ; Female ; HeLa Cells ; Humans ; Poly(ADP-ribose) Polymerase Inhibitors ; Radiation Tolerance/genetics* ; Repressor Proteins/metabolism* ; Trans-Activators/metabolism* ; Uterine Cervical Neoplasms/radiotherapy*

Objective: To study the effect of circ-WHSC1 on the growth, metastasis and radiosensitivity of nasopharyngeal carcinoma cells and its molecular mechanism. Methods: Cancerous tissues and adjacent tissues were collected from 23 patients with nasopharyngeal carcinoma, and real-time fluorescent quantitative PCR (RT-qPCR) was used to detect the expression levels of circ-WHSC1, miR-338-3p, and ELAVL1 mRNA. Western blot was used to detect the expression of ELAVL1 protein. Nasopharyngeal carcinoma cells 5-8F and SUNE1 were divided into si-NC group, si-circ-WHSC1 group, pCD5-ciR group, circ-WHSC1 group, anti-miR-NC group, anti-miR-338-3p group, miR-NC group, miR-338-3p group, si-circ-WHSC1+ anti-miR-NC group, si-circ-WHSC1+ anti-miR-338-3p group, miR-338-3p+ pcDNA group, miR-338-3p+ ELAVL1 group. Tetramethylazolium salt colorimetric method (MTT) was used to detect cell viability. Clone formation test was used to detect cell clone formation and cell radiosensitivity. Flow cytometry was used to detect cell apoptosis. Transwell was used to detect cell migration and invasion. Dual luciferase assay was used to detect the targeting relationship between circ-WHSC1 and miR-338-3p, miR-338-3p and ELAVL1. The SUNE1 cells stably transfected with sh-circ-WHSC1 were injected into nude mice and irradiated with radiation, and then the tumor volume and weight of mice were detected. Results: The expressions of circ-WHSC1 (1.57±0.94 vs 3.78±1.18, 1.00±0.10 vs 1.64±0.14/2.00±0.21/2.81±0.26/3.36±0.34) and ELAVL1 (1.28±0.74 vs 3.36±0.77, 1.00±0.08 vs 2.51±0.19/3.27±0.27) in nasopharyngeal carcinoma tissues and cells were increased, and the expression of miR-338-3p (3.13±0.96 vs 1.37±0.98, 1.00±0.08 vs 0.48±0.08/0.38±0.07) was decreased (P<0.05). After knockdown of circ-WHSC1, the activity of nasopharyngeal carcinoma cells was decreased [(100.00±8.00)% vs (51.33±8.62)%, (100.00±10.10)% vs (41.02±7.31)%], the number of clone-forming cells was decreased (101.00±8.54 vs 50.33±8.02, 114.00±14.10 vs 42.33±10.01), the rate of apoptosis was increased [(5.37±1.20)% vs (18.3±1.01)%, (6.5±1.18)% vs (22.43±1.40)%], and the numbers of migration (136.00±13.00 vs 72.33±9.50, 154.00±14.10 vs 62.67±11.50) and invasion (113.67±11.59 vs 60.67±9.07, 124.33±15.57 vs 50.33±9.01) were decreased; after different doses of radiation, the cell survival score was decreased (0.23±0.04 vs 0.06±0.01, 0.32±0.07 vs 0.05±0.02) (P<0.05). Circ-WHSC1 targeted and negatively regulated miR-338-3p. Inhibition of miR-338-3p affected the effect of knockdown of circ-WHSC1 on the proliferation, apoptosis, migration, invasion and radiosensitivity of nasopharyngeal carcinoma cells. MiR-338-3p targeted and negatively regulated ELAVL1; ELAVL1 overexpression affected the effects of miR-338-3p on the proliferation, apoptosis, migration, invasion and radiosensitivity of nasopharyngeal carcinoma cells. After the cells stably transfected with sh-circ-WHSC1 were injected into nude mice, the tumor volume [(884.67±95.63)mm(3) vs (487.33±76.51)mm(3)] and weight [(899.01±88.54)mg vs (558.67±75.04) mg] of the nude mice were reduced; after further irradiation, the tumor volume [(395.00±73.50)mm(3) vs 243.13±42.51)mm(3)] and weight[ (452.33±67.30)mg vs (211.09±57.51)mg] of the nude mice were reduced (P<0.05). Circ-WHSC1 regulated the expression of ELAVL1 by targeting miR-382. Conclusion: Knockdown of circ-WHSC1 can inhibit the growth and metastasis of nasopharyngeal carcinoma cells by targeting miR-338-3p/ELAVL1 axis, and enhances the radiosensitivity of nasopharyngeal carcinoma cells.
Mice ; Animals ; Nasopharyngeal Carcinoma/radiotherapy* ; Mice, Nude ; MicroRNAs/genetics* ; Antagomirs ; Cell Line, Tumor ; Radiation Tolerance/genetics* ; Nasopharyngeal Neoplasms/pathology* ; Cell Proliferation/genetics* ; Gene Expression Regulation, Neoplastic

OBJECTIVES: Radiotherapy is one of the main therapies for colorectal cancer, but radioresistance often leads to radiotherapy failure. To improve the radioresistance, we explore the effect of oligomycin A, the H METHODS: The effects of different concentrations of oligomycin A on the survival rate and glycolysis of HT29 colorectal cancer cells at different time points were investigated via MTT and glycolysis assay. siRNA-PFK1 was synthesized in vitro and transfected into HT29 cells. The effects of oligomycin A on radiosensitivity of HT29 colorectal cancer cells were measured via MTT and colony formation assay. Western blotting was used to detect the effect of oligomycin A on the expression of glycolytic enzyme PFK1. We compared difference between the effects of siRNA-PFK1 group and oligomycin A combined with siRNA-PFK1 group on cell survival and glycolysis. After 4 Gy X-ray irradiation, the effects of cell survival and glycolysis between the siRNA-PFK1 group and the oligomycin A combined with siRNA-PFK1 group were compared. RESULTS: Compared with the 0 μmol/L oligomycin A group, the cell survival rate of HT29 cells treated with 4 μmol/L oligomycin A was significantly increased ( CONCLUSIONS Oligomycin A can promote the radioresistance of HT29 colorectal cancer cells, which may be related to up-regulation of the PFK1 expression and increase of cell glycolysis.
Cell Line, Tumor ; Colorectal Neoplasms/genetics* ; HT29 Cells ; Humans ; Oligomycins/pharmacology* ; Radiation Tolerance

Objective: To explore the impacts of miR-18a overexpression or depression on the radiosensitivities of nasopharyngeal carcinoma cell line CNE1 and CNE2 and underlying mechanisms. Methods: CNE1 and CNE2 were transfected with miR-18a mimics, inhibitor and the corresponding control vectors. qRT-PCR and western blot were used to determine the ataxia telangiectasia mutated (ATM) expressions in CNE1 and CNE2. CNE1 and CNE2 with stably expressing miR-18a and miR-18a siRNA were constructed. Methyl thiazolyl tetrazolium (MTT) assay was used to detect the impacts of the miR-18a overexpression or depression combined with irradiation on the cell growth. Flow cytometry was used to detect the cell apoptosis and cell cycle. Colony formation assay was used to evaluate the raodiosensitivities of cells. Acridine orange (AO) staining and western blot were used respectively to test the autophagy and the expressions of related proteins. Independent samples t test was used to compare the mean value between groups by using SPSS 16.0. Results: ATM mRNA was decreased significantly in CNE1 and CNE2 cells transfected with 100 or 200 nmol/L miR-18a mimics for 48 hours (CNE1: RQ=0.174±0.139 and 0.003±0.001, t=9.939 and 19 470.783;CNE2: RQ=0.024±0.008 and 0.019±0.012, t=270.230 and 137.746, respectively, all P<0.001). ATM proteins were also decreased after transfected with 100 or 200 nmol/L miR-18a mimics for 72 hours. While in the cells transfected with 100 and 200 nmol/L miR-18a inhibitor for 48 hours, the expressions of ATM mRNA were upregulated significantly (CNE1: RQ=9.419±2.495 and 2.500±1.063, t=-4.427 and -41.241; CNE2: RQ=7.210±0.171 and 115.875±15.805, t=-62.789 and -12.589, all P<0.05), and the expressions of ATM proteins increased after transfected for 72 hours. The growth of cells with miR-18a overexpression plus 4 Gy irradiation were obviously inhibited compared to that of cells with the 4Gy irradiation alone; while the growth of miR-18a-inhibited cells increased compared to that of cells with 4 Gy irradiation alone (all P<0.05). CNE1 transfected with 100 nmol/L miR-18a mimics plus 4 Gy irradiation showed the higher apoptosis rate than the cells with 4 Gy irradiation alone ((22.9±2.1)% vs. (16.3±1.0)%, t=-4.870, P<0.01). Compared to the cells with 4 Gy irradiation alone, miR-18a-overexpressed cells plus 4 Gy irradiation decreased their percentages in G1 phases ((20.2±3.0)% vs. (29.8±4.4)%, t=3.119) and G2/M phases ((21.5±0.9)% vs. (33.4±3.1)%, t=6.410, P<0.05 for both), and increased their percentages in S phases ((56.7±4.9)% vs. (36.8±6.4)%, t=-4.246, P<0.05), and these cells possessed less colony number after exposure to different doses of irradiation, more autophagy-lysosome number, and more expressions of LC3 proteins (all P<0.05). There were no significant differences in the expressions of p62 expressions between different groups of cells. Conclusion: Overexpression of miR-18a can enhance the radiosensitivities of NPC cells by targeting ATM to abrogate G1/S, G2/M arrest and to induce autophagy and apoptosis.
Apoptosis ; Autophagy ; Cell Line, Tumor ; Cell Proliferation ; G2 Phase Cell Cycle Checkpoints ; Humans ; MicroRNAs/genetics* ; Nasopharyngeal Carcinoma/genetics* ; Nasopharyngeal Neoplasms/genetics* ; Radiation Tolerance

OBJECTIVE: To explore the effect of mmu-circRNA_016901 on the regulation of radiation injury of bone marrow stem cells and its mechanism. METHODS: Bone marrow stem cells were exposed to different dose of X-ray, then the expression level of mmu-circRNA_016901 in bone marrow cells treated with different doses of X-ray was detected. The luciferase reporter gene assay was used to confirm that miRNA1249-5p is the target of mmu-circRNA_016901, and RNA Binding Protein Immunoprecipitation was used to confirm that TGF-β3 is the targeted on miRNA1249-5p，the expression of TGF-β3 and cell proliferation were detected after the expression of mmu-circRNA_01690 was regulated. RESULTS: When the irradiation dose＜6 Gy, there were significant difference in the expression of mmn-circRNA-016901 after the bone marrow mesenchymal stem cells were treated by different doses of irradiation, which showed a statistically significant (P＜0.05). The luciferase reporter gene detection and co-immunoprecipitation experiments confirmed that Mmu-circRNA_016901 could binds to miRNA1249-5p specifically, and overexpression of mmu-circRNA_016901 could regulate miRNA1249-5p negatively, which resulted in a significant increase in TGF-β3 expression and promoting of cell proliferation. CONCLUSION mmu-circRNA_016901 affects the expression of TGF-β3 through miRNA1249-5p, and thus participates in the regulation of the radiation damage mechanism of bone marrow mesenchymal stem cells.
Bone Marrow Cells ; Mesenchymal Stem Cells ; RNA, Circular ; genetics ; Radiation Tolerance

Objective: To detect the effects of shortwave radiation on dose-dependent cardiac structure and function in rats after radiation and to elucidate the mechanism of shortwave radiation induced cardiac injury to identify sensitive indicators and prophylactic treatment. Methods: One hundred Wistar rats were either exposed to 27 MHz continuous shortwave at a power density of 5, 10, and 30 mW/cm for 6 min or undergone sham exposure for the control (the rats had to be placed in the exposure system with the same schedules as the exposed animals, but with an inactive antenna). The Ca , glutamic oxaloacetic transaminase (AST), creatine kinase (CK) and lactate dehydrogenase (LDH) content in the peripheral serum of the rats were detected by an automatic blood biochemical analyser. The electrocardiogram (ECG) of standard lead II was recorded by a multi-channel physiological recording and analysis system. The cardiac structure of rats was observed by light and electron microscopy. Results: The results showed that the 5, 10, and 30 mW/cm shortwave radiation caused a significant increased in the levels of Ca , AST, CK, and LDH in the peripheral serum of rats. The cardiac structure was damaged by radiation and showed a disordered arrangement of myocardial fibres, the cavitation and swelling of myocardial mitochondria. These injuries were most significant 7 d after radiation and were not restored until 28 d after radiation. Conclusion Shortwave radiation of 5, 10, and 30 mW/cm can damage rat cardiac function, including damage to the tissue structure and ultrastructure, especially at the level of the myocardial fibres and mitochondria. Shortwave radiation at 5, 10, and 30 mW/cm induced damage to rat heart function and structure with a dose-effect relationship, i.e., the greater the radiation dose was, the more significant the damage was.
Animals ; Dose-Response Relationship, Radiation ; Heart ; radiation effects ; Heart Diseases ; ethnology ; pathology ; physiopathology ; Male ; Myocardium ; pathology ; Radio Waves ; adverse effects ; Random Allocation ; Rats ; Rats, Wistar

DNA Methylation ; radiation effects ; Dose-Response Relationship, Radiation ; Hematologic Neoplasms ; metabolism ; radiotherapy ; Neoplasms ; metabolism ; radiotherapy ; X-Rays