International journal of radiation biology最新文献

Background: Microbeam radiation therapy (MRT) seeks to improve the therapeutic ratio of conventional radiation therapy though the delivery of high doses in micrometre-scale beamlets of synchrotron-generated X-rays.

Purpose: To assess the MRT experimental setups and biological endpoints used in preclinical studies investigating its therapeutic potential in lung cancer models.

Methodology: PubMed, Embase, Science Direct, and Web of Science were searched using the following keywords, 'microbeam', 'micro beam', 'synchrotron' and 'lung'. The reported physical parameters of the MRT set up and biological endpoints chosen to test efficacy were examined.

Main findings: Fourteen studies were assessed. The microbeam widths ranged from 25 µm to 630 µm, and the microbeam spacing ranged from 0 µm to 4000 µm. The peak doses ranged up to 1000 Gy and dose rates ranged from 4 Gy/s to 1.4x10⁴ Gy/s. Fibrosis was the most commonly assessed radiation-induced toxicity.

Conclusion: MRT experimental set ups and biological endpoints are heterogeneous. Standardization could strengthen future evidence supporting its use for the management of patients with lung cancer.

Purpose: The micro-distribution of boron compounds within cells influences the effectiveness of boron neutron capture therapy (BNCT) in killing tumor cells. Boron neutron capture therapy-sensitive organelles within the range of α particles and ⁷Li recoil nuclei can enhance killing effects on tumor cells. However, comprehensive studies on the sensitive organelles to BNCT are currently lacking. In the present study, we explored the sensitivity of organelles in U251 MG glioblastomas to BNCT.

Materials and methods: Trypan blue exclusion assay, the level of autophagic proteins, cell counting kit-8, and clonogenic formation assay were used to evaluate the sensitivity of the cellular membrane, the endoplasmic reticulum, the mitochondria, and the cell nuclei of U251 MG glioblastomas to BNCT (¹⁰B atoms of L-4-boronophenylalanin capture neutrons).

Results: Boron neutron capture therapy induced a trypan blue exclusion rate of 93.33%, no changes in the levels of LC3-II and Beclin-1, a survival rate of 77.78%, and reproductive death of 90.25% in U251 MG glioblastomas. These results indicate a hierarchical sensitivity of U251 MG glioblastoma organelles to BNCT ranked as the cell membrane (the endoplasmic reticulum) < the mitochondria < and the cell nucleus. Reproductive death, the main type of U251 MG glioblastoma death induced by BNCT, is attributed to the shortening of the S phase duration.

Conclusions: The comprehensive understanding of sensitive organelles within tumor cells to BNCT lays the foundation for significantly improving the efficacy of BNCT in killing tumor cells.

Introduction: Knee osteoarthritis (OA) is a prevalent chronic condition characterized by progressive damage to the articular cartilage, resulting in chronic pain, swelling, and reduced range of motion with a range of prevalence of 10-40%. This study aims to investigate the efficacy of low-dose radiation as a local treatment option for knee OA symptoms.

Methods: In this prospective study, patients with confirmed OA and older than 65 years were randomly assigned to treatment and control groups. The protocol plan IRCT20160706028815N6 was registered in Iranian registry of clinical trials system. The treatment group received 3 Gy radiation over six fractions, while the control group continued routine treatment without radiation. The pain intensity and functional levels were assessed at pretreatment and each month following completion of therapy for six consecutive months by Visual Analog Scale (VAS) and the Lysholm 100-point Scale, respectively. Analgesic medication usage and performance status (PS) were also assessed.

Results: The mean age of the patients was 77 years (range 72-89). All variables including VAS pain score, Lysholm scale, PS and analgesic consumption were improved following radiation from first month to the end of assessments (p value <0.01).

Conclusion: Results showed significant pain score improvements and enhanced joint function with no adverse effects. Findings were compared with previous studies, revealing mixed conclusions on low dose radiation therapy (LDRT) efficacy. Mechanistic hypotheses suggest LDRT may modulate inflammatory pathways. The study suggests LDRT at 3 Gy could benefit knee osteoarthritis patients and calls for further research on mechanisms of action in early-stage osteoarthritis.

Objectives: The present study aims to investigate the changes in the expression levels of miR-675 and some selenoproteins (Sel K, Sel W, and Sel P) in patients with breast cancer, before and after radiotherapy.

Subjects and methods: This study included 35 breast cancer patients who applied to the Department of Radiation Oncology for radiotherapy and 25 healthy female controls. miR-675 expressions were analyzed by using quantitative reverse-transcription polymerase chain reaction (qRT-PCR). Western blot was conducted to determine Sel K, Sel W, and Sel P expression levels. Biochemical parameters and complete blood count were analyzed by autoanalyzer system and automatic cell counter, respectively.

Results: Plasma Sel K protein expression levels were decreased in the after-radiotherapy group compared to the control and before-radiotherapy groups, but plasma miR-675 expression levels were lower in both before and after radiotherapy groups compared to the control group.

Conclusion: Our findings showed that miR-675 and Sel K expression levels changed after radiotherapy in breast cancer patients. These changes may have the potential to be biomarkers for the effectiveness of radiotherapy in breast cancer.

Purpose: To investigate the effects of radical radiotherapy (RT) relevant interruptions (RRI), single (sRRI) or multiple (mRRI), on Biochemical Failure-Free Survival (BFFS), Metastases-Free Survival (MFS) and Overall Survival (OS) in prostate cancer (PCa) patients.

Methods: We conducted a retrospective analysis involving 383 patients diagnosed with prostate cancer (PCa) who received radical RT between March 2013 and April 2021, with doses ranging from 60 to 80 Gy (median dose 76.0 Gy), either alone or in combination with androgen deprivation therapy. The study aimed to evaluate the effects of sRRI and mRRI radiation-related interruptions on BFFS, MFS, and OS using the Kaplan-Meier method. Additionally, we adjusted for relevant prognostic factors using three multivariate Cox regression proportional hazard models.

Results: In the univariate analysis, it was observed that patients who experienced unexpected RRIs (50.1%: 35.5% sRRI and 14.6% mRRI), resulting in a median overall treatment time prolongation of five days, exhibited a higher incidence of biochemical failure (BF) and metastases (Met). However, no difference was observed in OS. In the multivariate analysis, it was found that RRIs were significantly associated with increased hazards of BF (sRRI, aHR: 4.61, 95% CI: 2.80-7.60; mRRIs, aHR: 9.92, 95% CI: 5.61-17.54), Met (sRRI, aHR: 4.20, 95% CI: 1.97-8.94; mRRI, aHR: 7.01, 95% CI: 2.94-6.71), and all-cause mortality (mRRI, aHR: 1.89, 95% CI: 1.18-3.03).

Conclusions: sRRIs were associated with both lower BFFS and MFS, while mRRIs with both BFFS, MFS and OS.

Purpose: Prohibitin2 (PHB2), located in inner mitochondrial membrane (IMM), is an important receptor to induce mitophagy. PHB2 was identified as a cancer-promoting factor in most cancers. However, the function of PHB2 in glioma cells remains unclear. This study delved into the impact of PHB2 knockdown on the phenotype, radiosensitivity and mitophagy of glioma cells.

Methods: PHB2 expression and its clinical relevance in glioma were investigated by western blot, quantitative reverse transcription polymerase chain reaction (qRT-PCR) and TCGA databases. The malignant phenotypes of glioma cells were analyzed in vitro using cell proliferation, cell cycle, wound healing and transwell assay. The radiosensitivity of glioma cells was detected by colony forming assay. The potential mechanism by which PHB2 regulated mitophagy was investigated by coimmunoprecipitation assay.

Results: The expression of PHB2 was significantly upregulated in glioma cells and closely correlated with the malignant degree of glioma. The knockdown of PHB2 inhibited the proliferation, migration and invasion activities of glioma cells. Furthermore, PHB2 knockdown enhanced the radiosensitivity of normoxic and hypoxic glioma cells and suppressed the ionizing radiation-induced mitophagy in glioma cells. Cyanide 3-chlorophenylhydrazone (CCCP), a mitophagy agonist, could reverse the phenotypes and radiosensitivity changes elicited by PHB2 knockdown. Additionally, PHB2 regulated the expression of PGAM5 and PINK1 by directly binding to PARL.

Conclusions: Our findings revealed that PHB2 knockdown decreased glioma malignant phenotypes and radio-resistance by inhibiting mitophagy via PARL-PGAM5-PINK1-Parkin pathway. PHB2 is a promising candidate target for the development of new therapeutic strategy to enhance the efficacy of radiotherapy for glioma.

Purpose: To retrospectively observe the effects of long-term low-dose 2.45 GHz microwave electromagnetic radiation on human vulnerable organs.

Methods: This single-center, retrospective cohort study investigated patients who received long-term (20-100 times of microwave therapy within three months) low-dose (≤20 W) microwave therapy in our department five years ago. Patients were identified and followed up using a rehabilitation treatment management system. Adverse events or diseases that developed after microwave treatment were collected. Based on the number of microwave exposures, patients were divided into two groups: the multiple irradiation group (20-50 sessions) and the ultra-multiple irradiation group (50-100 sessions). The incidence of irreversible damage (ocular lesions, nervous system diseases, reproductive system diseases, cardiovascular system diseases, tumors, or early precancerous lesions) within five years after treatment completion was compared between the two groups.

Results: A total of 113 valid cases were analyzed. Sixteen adverse events occurred, including two cases related to tumors, nine cases related to cardiovascular and cerebrovascular diseases, five cases related to metabolic diseases, and one case related to nervous system diseases. One patient had multiple conditions. There was no significant difference in the incidence of adverse events between the multiple irradiation group and the ultra-multiple irradiation group (p = .161, OR = 0.307, 95% CI 0.088-1.025). Logistics regression analysis revealed that the number of microwave treatments, treatment frequency per week, and patient gender was not a significant risk factor for adverse events (p = .100, OR = 0.972, 95% CI 0.938-1.006; p = .896, OR = 1.028, 95% CI 0.679-1.575; p = .960, OR = 1.039, 95% CI 0.212-4.609). Advanced age and obesity might be contributing factors for adverse events (p = .001, OR = 0.923, 95% CI 0.877-0.965; p = .002, OR = 0.064, 95% CI 0.009-0.348).

Conclusions: Based on this study, receiving less than 100 sessions of low-dose microwave therapy within three months appears to be safe. Advanced age and obesity might increase the risk of adverse events. Due to the deviation that may be caused by the small sample size of this study, it is necessary to carry out prospective randomized controlled studies with larger samples in the future for further verification.

Purpose: The objective of this study was to ascertain the impact of varying dosages of gamma irradiation on the germination and development of Quercus frainetto acorns.

Materials and methods: The acorns were subjected to gamma radiation from a cobalt-60 source at doses of 25, 50, 100, and 200 gray. The germination percentage, mean germination time, and radicle length of the acorns were quantified. Images were used to evaluate the radicle length. Correlation was employed to investigate the relationships between gamma radiation treatments and moisture content, tetrazolium staining, germination percentage, mean germination time, and radicle length.

Results: The impact of gamma-ray radiation on acorns was found to significantly affect moisture content, viability, germination percentage, mean germination time, and radicle length. The germination percentage indicated a decline, particularly at 100 Gy. The acorn lots subjected to 25 grays had the highest germination percentage (92%). The germination percentage in the acorn lots treated with 200 grays decreased by approximately half (44%) in comparison to the control (86%), while the radicle length decreased from 14.8 cm to approximately one-tenth (1.4 cm).

Conclusions: The findings demonstrated that the germination percentage and radicle length declined with elevated gamma radiation intensity. While low doses of gamma (25 grays) radiation may facilitate germination, higher doses can exert detrimental effects, including the suppression or complete inhibition of germination. The application of gamma treatment has been demonstrated to be an effective method of inhibiting radicle length elongation, a process that is crucial for the storage and postharvest seeding of acorns.

Purpose: Radiotherapy is the main treatment for non-distant metastatic nasopharyngeal carcinoma (NPC). However, about 15% of NPC patients still experience local tumor recurrence after radiotherapy. The mechanisms underlying the radioresistance of NPC have not been fully understood. This study explored the role of phosphoenolpyruvate carboxykinase2 (PCK2) in NPC radiosensitivity.

Methods: Two NPC cell lines, SUNE-1 and 5-8 F, were enrolled in this research, and their radioresistant counterparts, SUNE-1R and 5-8FR were obtained by long-term exposure to γ-ray (2 Gy*30 times). Cells response to ionizing radiation (IR) was determined by colony formation assay (C.F.A). Immunofluorescence, microsphere formation assay and ferroptosis test were adopted to compare the difference of DNA damage repair, stemness and cell death between sensitive and resistant NPC cells. The biological functions of PCK2 were investigated by knocking down the endogenous PCK2 in vitro and in vivo. In addition, the tumor morphology and related markers were observed by HE staining and immunohistochemistry assay, respectively.

Results: Intracellular PCK2 is transiently upregulated after a single irradiation in both SUNE-1 and 5-8 F cells. However, PCK2 was significantly reduced in radiation-tolerant cells that survived from multiple irradiations. Further work showed that PCK2 down-regulation prevented SUNE-1R and 5-8FR cells from IR-induced ferroptosis, accompanied by increased cell ability of DNA damaged repair and enhanced phenotypes of tumor stem cells.

Conclusions: Our findings indicate that low expression of PCK2 is an important phenotypic feature of radioresistant NPC cells. It could be a result of PCK2 involved in regulating radiation-induced ferroptosis. Regulating the expression of PCK2 may provide new strategies for improving NPC radiation sensitivity.

Purpose: Acute myeloid leukemia (AML) is a deadly form of leukemia, and its treatment often leaves patients immunocompromised, making them vulnerable to fungal infections. Radioimmunotherapy (RIT) is explored for both AML and fungal infections. This study compares the radiobiological effects of alpha emitter Actinium-225 (²²⁵Ac) and beta emitter Lutetium-177 (¹⁷⁷Lu)-labeled antibodies on AML and Cryptococcus neoformans cells.

Materials and methods: AML OCI-AML3 and C. neoformans Cap-67 cells were treated with anti-(1-3)-beta-glucan antibody 400-2 and anti-CD33 antibody HuM-195, conjugated to DOTA and radiolabeled with ²²⁵Ac or ¹⁷⁷Lu. Clonogenic survival, γH2A/X staining, and micronuclei assays were conducted. Antibody internalization was assessed by flow cytometry.

Results: Both ²²⁵Ac- and ¹⁷⁷Lu-enabled RIT resulted in decreased clonogenic survival in Cap-67 and OCI-AML3 cells, with Cap-67 recovering more rapidly. DNA double-strand breaks and micronuclei formation revealed DNA damage, with fewer micronuclei in OCI-AML3 cells due to radiation destruction. HuM-195 antibody internalized into OCI-AML3 cells, whereas 400-2 did not internalize into Cap-67 cells.

Conclusions: While both cell lines showed similar responses to ²²⁵Ac- and ¹⁷⁷Lu-enabled RIT, variations were observed based on cellular structure, doubling times and DNA repair mechanisms. This study offers insights for future in vivo research on fungal infections in cancer setting.