Radiation-induced upregulation of FGL1 promotes esophageal squamous cell carcinoma metastasis via IMPDH1.

BACKGROUND: While radiation therapy remains pivotal in esophageal squamous cell carcinoma (ESCC) treatment, the perplexing phenomenon of post-radiation metastasis presents a formidable clinical challenge. This study investigates the role of fibrinogen-like protein 1 (FGL1) in driving ESCC metastasis following radiation exposure. METHODS: FGL1 expression in post-radiation ESCC cells was meticulously examined using qRT-PCR, western blotting, and immunofluorescence. The impact of FGL1 on ESCC cell invasion and migration was assessed through Transwell and wound healing assays. In vivo, the metastatic potential of ESCC in response to FGL1 was scrutinized using nude mice models. Comprehensive RNA sequencing and functional experiments elucidated the intricate mechanism associated with FGL1. RESULTS: Radiation induced upregulation of FGL1 in ESCC cells through FOXO4, intensifying ESCC cell invasion and migration. Targeted knockdown of FGL1 effectively alleviated these characteristics both in vitro and in vivo. FGL1 depletion concurrently suppressed IMPDH1 expression. Rescue experiments underscored that IMPDH1 knockdown robustly reversed the pro-invasive effects induced by FGL1 in ESCC cells. ESCC tissues exhibited heightened IMPDH1 mRNA levels, demonstrating a correlation with patient survival. CONCLUSIONS: Radiation-induced upregulation of FGL1 propels ESCC metastasis through IMPDH1, proposing a potential therapeutic target to mitigate post-radiotherapy metastasis in ESCC patients.

Rapid P-TEFb-dependent transcriptional reorganization underpins the glioma adaptive response to radiotherapy.

Dynamic regulation of gene expression is fundamental for cellular adaptation to exogenous stressors. P-TEFb-mediated pause-release of RNA polymerase II (Pol II) is a conserved regulatory mechanism for synchronous transcriptional induction in response to heat shock, but this pro-survival role has not been examined in the applied context of cancer therapy. Using model systems of pediatric high-grade glioma, we show that rapid genome-wide reorganization of active chromatin facilitates P-TEFb-mediated nascent transcriptional induction within hours of exposure to therapeutic ionizing radiation. Concurrent inhibition of P-TEFb disrupts this chromatin reorganization and blunts transcriptional induction, abrogating key adaptive programs such as DNA damage repair and cell cycle regulation. This combination demonstrates a potent, synergistic therapeutic potential agnostic of glioma subtype, leading to a marked induction of tumor cell apoptosis and prolongation of xenograft survival. These studies reveal a central role for P-TEFb underpinning the early adaptive response to radiotherapy, opening avenues for combinatorial treatment in these lethal malignancies.

BCL6 is a context-dependent mediator of the glioblastoma response to irradiation therapy.

Glioblastoma is a rapidly fatal brain cancer that does not respond to therapy. Previous research showed that the transcriptional repressor protein BCL6 is upregulated by chemo and radiotherapy in glioblastoma, and inhibition of BCL6 enhances the effectiveness of these therapies. Therefore, BCL6 is a promising target to improve the efficacy of current glioblastoma treatment. BCL6 acts as a transcriptional repressor in germinal centre B cells and as an oncogene in lymphoma and other cancers. However, in glioblastoma, BCL6 induced by therapy may not be able to repress transcription. Using a BCL6 inhibitor, the whole proteome response to irradiation was compared with and without BCL6 activity. Acute high dose irradiation caused BCL6 to switch from repressing the DNA damage response to promoting stress response signalling. Rapid immunoprecipitation mass spectrometry of endogenous proteins (RIME) enabled comparison of BCL6 partner proteins between untreated and irradiated glioblastoma cells. BCL6 was associated with transcriptional coregulators in untreated glioblastoma including the known partner NCOR2. However, this association was lost in response to acute irradiation, where BCL6 unexpectedly associated with synaptic and plasma membrane proteins. These results reveal the activity of BCL6 under therapy-induced stress is context-dependent, and potentially altered by the intensity of that stress.

LILRB2 inhibition enhances radiation sensitivity in non-small cell lung cancer by attenuating radiation-induced senescence.

Radiotherapy (RT) in non-small cell lung cancer (NSCLC) triggers cellular senescence, complicating tumor microenvironments and affecting treatment outcomes. This study examines the role of lymphocyte immunoglobulin-like receptor B2 (LILRB2) in modulating RT-induced senescence and radiosensitivity in NSCLC. Through methodologies including irradiation, lentivirus transfection, and various molecular assays, we assessed LILRB2's expression and its impact on cellular senescence levels and tumor cell behaviors. Our findings reveal that RT upregulates LILRB2, facilitating senescence and a senescence-associated secretory phenotype (SASP), which in turn enhances tumor proliferation and resistance to radiation. Importantly, LILRB2 silencing attenuates these effects by inhibiting the JAK2/STAT3 pathway, significantly increasing radiosensitivity in NSCLC models. Clinical data correlate high LILRB2 expression with reduced RT response and poorer prognosis, suggesting LILRB2's pivotal role in RT-induced senescence and its potential as a therapeutic target to improve NSCLC radiosensitivity.

Increasing the radiation-induced cytotoxicity by silver nanoparticles and docetaxel in prostate cancer cells.

BACKGROUND: Radiation therapy is utilized for treatment of localized prostate cancer. Nevertheless, cancerous cells frequently develop radiation resistance. While higher radiation doses have not always been effective, radiosensitizers have been extensively studied for their ability to enhance the cytotoxic effects of radiation. So, this study aims to evaluate the possible radiosensitization effects of docetaxel (DTX) and silver nanoparticles (SNP) in LNCaP cells. METHODS: The cytotoxic effects of DTX, SNP and 2 Gy of X-Ray radiation treatments were assessed in human LNCaP cell line using the MTT test after 24 h. Moreover, the effects of DTX, SNP and radiation on Epidermal growth factor (EGF), Caspase 3, inducible nitric oxide synthase and E-cadherin gene expression were analyzed using the Real-time PCR method. The level of Hydrogen peroxide (H2O2), an oxidative stress marker, was also detected 24 h after various single and combined treatments. RESULTS: The combinations of SNP (in low toxic concentration) and/or DTX (0.25× IC50 and 0.5 × IC50 concentrations for triple and double combinations respectively) with radiation induced significant cytotoxicity in LNCaP cells in comparison to monotherapies. These cytotoxic effects were associated with the downregulation of EGF mRNA. Additionally, H2O2 levels increased after Radiation + SNP + DTX triple combination and double combinations including Radiation + SNP and Radiation + DTX versus single treatments. The triple combination treatment also increased Caspase 3 and and E-cadherin mRNA levels in compared to single treatments in LNCaP cells. CONCLUSION: Our results indicate that the combination of SNP and DTX with radiation induces significant anti-cancer effects. Upregulation of Caspase 3 and E-cadherin gene expression, and decreased mRNA expression level of EGF may be exerted specifically by use of this combination versus single treatments.

Blocking the ATR-SerRS-VEGFA pathway targets angiogenesis for UV-induced cutaneous squamous cell carcinoma.

Cutaneous squamous cell carcinoma (cSCC) is the second most prevalent form of skin cancer, with an escalating incidence rate and a notable potential (up to 5%) for metastasis. Ultraviolet radiation (UVA and UVB) exposure is the primary risk factor for cSCC carcinogenesis, with literature suggesting ultraviolet radiation (UVR) promotes vascular endothelial growth factor A (VEGFA) expression. This study aims to investigate UVR-induced upregulation of VEGFA and explore combination therapeutic strategies. The skin squamous cell carcinoma cell line A431 was exposed to specific durations of ultraviolet radiation. The effect of emodin on ATR/SerRS/VEGFA pathway was observed. The cell masses were also transplanted subcutaneously into mice (n = 8). ATR inhibitor combined with emodin was used to observe the growth and angiogenesis of the xenografts. The results showed that UV treatment significantly enhanced the phosphorylation of SerRS and the expression level of VEGFA in A431 cells (p < 0.05). Treatment with emodin significantly inhibited this expression (p < 0.05), and the combination of emodin and ATR inhibitor further enhanced the inhibitory effect (p < 0.05). This phenomenon was further confirmed in the xenograft model, which showed that the combination of ATR inhibitor and emodin significantly inhibited the expression of VEGFA to inhibit angiogenesis (p < 0.05), thus showing an inhibitory effect on cSCC. This study innovatively reveals the molecular mechanism of UV-induced angiogenesis in cSCC and confirms SerRS as a novel target to inhibit cSCC angiogenesis and progression in vitro and in vivo studies.

Molecular mechanism of radiation tolerance in lung adenocarcinoma cells using single-cell RNA sequencing.

The efficacy of radiotherapy, a cornerstone in the treatment of lung adenocarcinoma (LUAD), is profoundly undermined by radiotolerance. This resistance not only poses a significant clinical challenge but also compromises patient survival rates. Therefore, it is important to explore this mechanism for the treatment of LUAD. Multiple public databases were used for single-cell RNA sequencing (scRNA-seq) data. We filtered, normalized and downscaled scRNA-seq data based on the Seurat package to obtain different cell subpopulations. Subsequently, the ssGSEA algorithm was used to assess the enrichment scores of the different cell subpopulations, and thus screen the cell subpopulations that are most relevant to radiotherapy tolerance based on the Pearson method. Finally, pseudotime analysis was performed, and a preliminary exploration of gene mutations in different cell subpopulations was performed. We identified HIST1H1D+ A549 and PIF1+ A549 as the cell subpopulations related to radiotolerance. The expression levels of cell cycle-related genes and pathway enrichment scores of these two cell subpopulations increased gradually with the extension of radiation treatment time. Finally, we found that the proportion of TP53 mutations in patients who had received radiotherapy was significantly higher than that in patients who had not received radiotherapy. We identified two cellular subpopulations associated with radiotherapy tolerance, which may shed light on the molecular mechanisms of radiotherapy tolerance in LUAD and provide new clinical perspectives.

Profile of miRNAs in small extracellular vesicles released from glioblastoma cells treated by boron neutron capture therapy.

PURPOSE: Boron neutron capture therapy (BNCT) is a tumor cell-selective particle-radiation therapy. In BNCT, administered p-boronophenylalanine (BPA) is selectively taken up by tumor cells, and the tumor is irradiated with thermal neutrons. High-LET α-particles and recoil 7Li, which have a path length of 5-9 µm, are generated by the capture reaction between 10B and thermal neutrons and selectively kill tumor cells that have uptaken 10B. Although BNCT has prolonged the survival time of malignant glioma patients, recurrences are still to be resolved. miRNAs, that are encapsulated in small extracellular vesicles (sEVs) in body fluids and exist stably may serve critical role in recurrence. In this study, we comprehensively investigated microRNAs (miRNAs) in sEVs released from post-BNCT glioblastoma cells. METHOD: Glioblastoma U87 MG cells were treated with 25 ppm of BPA in the culture media and irradiated with thermal neutrons. After irradiation, they were plated into dishes and cultured for 3 days in the 5% CO2 incubator. Then, sEVs released into the medium were collected by column chromatography, and miRNAs in sEVs were comprehensively investigated using microarrays. RESULT: An increase in 20 individual miRNAs (ratio > 2) and a decrease in 2 individual miRNAs (ratio < 0.5) were detected in BNCT cells compared with non-irradiated cells. Among detected miRNAs, 20 miRNAs were associated with worse prognosis of glioma in Kaplan Meier Survival Analysis of overall survival in TCGA. CONCLUSION: These miRNA after BNCT may proceed tumors, modulate radiation resistance, or inhibit invasion and affect the prognosis of glioma.

NF-κB in the Radiation Response of A549 Non-Small Cell Lung Cancer Cells to X-rays and Carbon Ions under Hypoxia.

Cellular hypoxia, detectable in up to 80% of non-small cell lung carcinoma (NSCLC) tumors, is a known cause of radioresistance. High linear energy transfer (LET) particle radiation might be effective in the treatment of hypoxic solid tumors, including NSCLC. Cellular hypoxia can activate nuclear factor κB (NF-κB), which can modulate radioresistance by influencing cancer cell survival. The effect of high-LET radiation on NF-κB activation in hypoxic NSCLC cells is unclear. Therefore, we compared the effect of low (X-rays)- and high (12C)-LET radiation on NF-κB responsive genes' upregulation, as well as its target cytokines' synthesis in normoxic and hypoxic A549 NSCLC cells. The cells were incubated under normoxia (20% O2) or hypoxia (1% O2) for 48 h, followed by irradiation with 8 Gy X-rays or 12C ions, maintaining the oxygen conditions until fixation or lysis. Regulation of NF-κB responsive genes was evaluated by mRNA sequencing. Secretion of NF-κB target cytokines, IL-6 and IL-8, was quantified by ELISA. A greater fold change increase in expression of NF-κB target genes in A549 cells following exposure to 12C ions compared to X-rays was observed, regardless of oxygenation status. These genes regulate cell migration, cell cycle, and cell survival. A greater number of NF-κB target genes was activated under hypoxia, regardless of irradiation status. These genes regulate cell migration, survival, proliferation, and inflammation. X-ray exposure under hypoxia additionally upregulated NF-κB target genes modulating immunosurveillance and epithelial-mesenchymal transition (EMT). Increased IL-6 and IL-8 secretion under hypoxia confirmed NF-κB-mediated expression of pro-inflammatory genes. Therefore, radiotherapy, particularly with X-rays, may increase tumor invasiveness in surviving hypoxic A549 cells.

Vitexin enhances radiosensitivity of mouse subcutaneous xenograft glioma by affecting the miR-17-5p/miR-130b-3p/PTEN/HIF-1α pathway.

PURPOSE: Vitexin can cooperate with hyperbaric oxygen to sensitize the radiotherapy of glioma by inhibiting the hypoxia-inducible factor (HIF)-1α. However, whether vitexin has a direct radiosensitization and how it affects the HIF-1α expression remain unclear. This study investigated these issues. METHODS: The SU3 cells-inoculated nude mice were divided into control, radiation, and vitexin + radiation groups. The vitexin + radiation-treated mice were intraperitoneally injected with 75 mg/kg vitexin daily for 21 days. On the 3rd, 10th, and 17th days during the vitexin treatment, the radiation-treated mice were locally irradiated with 10 Gy, respectively. In vitro, the microRNA (miR)-17-5p or miR-130b-3p mimics-transfected SU3 cells were used to examine the effects of vitexin plus radiation on expression of miR-17-5p- or miR-130b-3p-induced radioresistance-related pathway proteins. The effects of vitexin on miR-17-5p and miR-130b-3p expression in SU3 cells were also evaluated. RESULTS: Compared with the radiation group, the tumor volume, tumor weight, and expression of HIF-1α, vascular endothelial growth factor, and glucose transporter-1/3 proteins, miR-17-5p, and miR-130b-3p in tumor tissues in the vitexin + radiation group decreased, whereas the expression of phosphatase and tensin homolog (PTEN) protein increased. After treatment of miR-17-5p or miR-130b-3p mimics-transfected SU3 cells with vitexin plus radiation, the PTEN protein expression also increased, the HIF-1α protein expression decreased correspondingly. Moreover, vitexin decreased the miR-17-5p and miR-130b-3p expression in SU3 cells. CONCLUSION: Vitexin can enhance the radiosensitivity of glioma, and its mechanism may partly be related to the attenuation of HIF-1α pathway after lowering the inhibitory effect of miR-17-5p and miR-130b-3p on PTEN.

Enhancing radiosensitivity in triple-negative breast cancer through targeting ELOB.

Enhancing radiotherapy sensitivity is crucial for improving treatment outcomes in triple-negative breast cancer (TNBC) patients. In this study, we investigated the potential of targeting Elongin B (ELOB) to enhance radiotherapy efficacy in TNBC. Analysis of TNBC patient cohorts revealed a significant association between high ELOB expression and poor prognosis in patients who received radiation therapy. Mechanistically, we found that ELOB plays a pivotal role in regulating mitochondrial function via modulating mitochondrial DNA expression and activities of respiratory chain complexes. Targeting ELOB effectively modulated mitochondrial function, leading to enhanced radiosensitivity in TNBC cells. Our findings highlight the importance of ELOB as a potential therapeutic target for improving radiotherapy outcomes in TNBC. Further exploration of ELOB's role in enhancing radiotherapy efficacy may provide valuable insights for developing novel treatment strategies for TNBC patients.

Radiation-induced changes in gene expression in rectal cancer specimens.

PURPOSE: The standard-of-care for locally advanced rectal cancer is radiotherapy-based neoadjuvant therapy followed by surgical resection. This article reviews the evidence of molecular changes at the transcriptome level induced through radiotherapy in rectal cancer. METHODS: The PubMed search "(radiation OR radiotherapy) cancer (transcriptome OR "gene expression") rectal" was used. The studies taken forward utilised gene-expression data on both pre-treatment and post-treatment rectal adenocarcinoma biospecimens from patients treated with RT-based neoadjuvant strategies. RESULTS: Twelve publications met the review criteria. There was variation in approaches in terms of design, patient population, cohort size, timing of the post-radiotherapy sampling and method of measuring gene expression. Most of the post-treatment biospecimen retrievals were at resection. The literature indicates a broad upregulation of immune activity through radiotherapy using gene-expression data. CONCLUSION: Future studies would benefit from standardised prospective approaches to sampling to enable the inclusion of timepoints relevant to the tumour and immune response.

Evaluation of the effects of simulated hypoxia by CoCl2 on radioresistance and change of hypoxia-inducible factors in human glioblastoma U87 tumor cell line.

PURPOSE: Glioblastoma (GBM) is considered the most common and lethal type of brain tumor with a poor prognosis. GBM treatment has challenges due to its aggressive nature, which often causes treatment failure and recurrence. Hypoxia is one of the characteristics of glioblastoma tumors that contribute to radioresistance and malignant phenotypes of GBM. In this study, we aimed to determine the effects of hypoxia on the radiosensitivity of U87 GBM cells by the hypoxia-mimicking model. METHODS: Following the treatment of cells with different concentrations of CoCl2, an MTT assay was used to evaluate the cytotoxicity of CoCl2. To understand the effects of Ionizing radiation on CoCl2-treated groups, cells were exposed to irradiation after pretreating with 100 µM CoCl2, and a clonogenic survival assay was performed to determine the radiosensitivity of U87 cells. Also, the intracellular Reactive oxygen level was measured by 2',7'-dichlorofluorescein diacetate (DCFDA) probe staining. Additionally, the expression of hypoxia-associated genes, including HIF-1α, HIF-2α, and their target genes (GLUT-1), was monitored by reverse transcription polymerase chain reaction (RT-PCR). RESULTS: Our study revealed that the cell viability of CoCl2-treated cells was decreased in a concentration-dependent manner. Also, CoCl2 did not cause any cytotoxicity on U87 cells at a concentration of 100 µM after treatment for 24 h. Colony formation assay showed that CoCl2 pretreatment induced radioresistance of tumor cells compared to non-treated cells. Also, CoCl2 can protect cells against irradiation by the clearance of ROS. Moreover, Real-time results showed that the mRNA expression of HIF-1α and GLUT-1 were significantly upregulated following hypoxia induction and/or irradiation condition. However, the level of HIF-2α mRNA did not change significantly in hypoxia or irradiation alone conditions, but it increased significantly only in hypoxia + irradiation conditions. CONCLUSION: Taken together, our results indicated that simulating hypoxia by CoCl2 can effectively increase hypoxia-associated genes, specially HIF-1α and GLUT-1, but did not affect HIF-2α gene expression. Also, it can increase the clearance of ROS, respectively, and it leads to inducing radioresistance of U87 cells.

Influence of Hypoxia on Radiosensitization of Cancer Cells by 5-Bromo-2'-deoxyuridine.

Radiotherapy is a crucial cancer treatment, but its outcome is still far from satisfactory. One of the reasons that cancer cells show resistance to ionizing radiation is hypoxia, defined as a low level of oxygenation, which is typical for solid tumors. In the hypoxic environment, cancer cells are 2-3 times more resistant to ionizing radiation than normoxic cells. To overcome this important impediment, radiosensitizers should be introduced to cancer therapy. When modified with an electrophilic substituent, nucleosides may undergo efficient dissociative electron attachment (DEA) that leaves behind nucleoside radicals, which, in secondary reactions, are able to induce DNA damage, leading to cancer cell death. We report the radiosensitizing effect of one of the best-known DEA-type radiosensitizers-5-bromo-2'-deoxyuridine (BrdU)-on breast (MCF-7) and prostate (PC3) cancer cells under both normoxia and hypoxia. MCF-7 and PC3 cells were treated with BrdU to investigate the effect of hypoxia on cell proliferation, incorporation into DNA and radiosensitivity. While the oxygen concentration did not significantly affect the efficiency of BrdU incorporation into DNA or the proliferation of tumor cells, the radiosensitizing effect of BrdU on hypoxic cells was more evident than on normoxic cells. Further mechanistic studies performed with the use of flow cytometry showed that under hypoxia, BrdU increased the level of histone H2A.X phosphorylation after X-ray exposure to a greater extent than under normal oxygenation conditions. These results confirm that the formation of double-strand breaks in hypoxic BrdU-treated cancer cells is more efficient. In addition, by performing stationary radiolysis of BrdU solution in the presence of an ●OH radical scavenger, we compared the degree of its electron-induced degradation under aerobic and anaerobic conditions. It was determined that radiodegradation under anaerobic conditions was almost twice as high as that under aerobic conditions.

Interactions between Radiation and One-Carbon Metabolism.

Metabolic reprogramming is a hallmark of cancer. Cancer cells rewire one-carbon metabolism, a central metabolic pathway, to turn nutritional inputs into essential biomolecules required for cancer cell growth and maintenance. Radiation therapy, a common cancer therapy, also interacts and alters one-carbon metabolism. This review discusses the interactions between radiation therapy, one-carbon metabolism and its component metabolic pathways.

Regulation of the Receptor Tyrosine Kinase AXL in Response to Therapy and Its Role in Therapy Resistance in Glioblastoma.

The receptor tyrosine kinase AXL (RTK-AXL) is implicated in therapy resistance and tumor progression in glioblastoma multiforme (GBM). Here, we investigated therapy-induced receptor modifications and how endogenous RTK-AXL expression and RTK-AXL inhibition contribute to therapy resistance in GBM. GBM cell lines U118MG and SF126 were exposed to temozolomide (TMZ) and radiation (RTX). Receptor modifications in response to therapy were investigated on protein and mRNA levels. TMZ-resistant and RTK-AXL overexpressing cell lines were exposed to increasing doses of TMZ and RTX, with and without RTK-AXL tyrosine kinase inhibitor (TKI). Colorimetric microtiter (MTT) assay and colony formation assay (CFA) were used to assess cell viability. Results showed that the RTK-AXL shedding product, C-terminal AXL (CT-AXL), rises in response to repeated TMZ doses and under hypoxia, acts as a surrogate marker for radio-resistance. Endogenous RTX-AXL overexpression leads to therapy resistance, whereas combination therapy of TZM and RTX with TKI R428 significantly increases therapeutic effects. This data proves the role of RTK-AXL in acquired and intrinsic therapy resistance. By demonstrating that therapy resistance may be overcome by combining AXL TKI with standard treatments, we have provided a rationale for future study designs investigating AXL TKIs in GBM.

CD44, γ-H2AX, and p-ATM Expressions in Short-Term Ex Vivo Culture of Tumour Slices Predict the Treatment Response in Patients with Oral Squamous Cell Carcinoma.

Squamous cell carcinoma is the most common type of head and neck cancer (HNSCC) with a disease-free survival at 3 years that does not exceed 30%. Biomarkers able to predict clinical outcomes are clearly needed. The purpose of this study was to investigate whether a short-term culture of tumour fragments irradiated ex vivo could anticipate patient responses to chemo- and/or radiotherapies. Biopsies were collected prior to treatment from a cohort of 28 patients with non-operable tumours of the oral cavity or oropharynx, and then cultured ex vivo. Short-term biopsy slice culture is a robust method that keeps cells viable for 7 days. Different biomarkers involved in the stemness status (CD44) or the DNA damage response (pATM and γ-H2AX) were investigated for their potential to predict the treatment response. A higher expression of all these markers was predictive of a poor response to treatment. This allowed the stratification of responder or non-responder patients to treatment. Moreover, the ratio for the expression of the three markers 24 h after 4 Gy irradiation versus 0 Gy was higher in responder than in non-responder patients. Finally, combining these biomarkers greatly improved their predictive potential, especially when the γ-H2AX ratio was associated with the CD44 ratio or the pATM ratio. These results encourage further evaluation of these biomarkers in a larger cohort of patients.

Irradiated fibroblasts increase interleukin-6 expression and induce migration of head and neck squamous cell carcinoma.

BACKGROUND: Cytotoxic effects of radiation play an important role in the treatment of head and neck cancer. However, irradiation is known to lead to the migration of various cancer cells, including those of head and neck cancer. Recently, fibroblasts in the cancer microenvironment have been reported to be involved in this mechanism. Nevertheless, the mechanism underlying migration of head and neck cancer cells remains unclear. Herein, we aimed to elucidate this migration mechanism induced by irradiation in terms of the interaction of head and neck cancer cells with fibroblasts. METHODS: We used the head and neck squamous cell carcinoma (HNSCC) cell lines SAS and FaDu as well as fibroblast cell lines. These cells were irradiated and their viability was compared. In fibroblasts, changes in interleukin-6 (IL-6) secretion caused by irradiation were measured by enzyme-linked immunosorbent assay (ELISA). The cell migration ability of cancer cells was evaluated via a migration assay using a semipermeable membrane. HNSCC cells were cocultured with irradiated and nonirradiated fibroblasts, and their migration ability under each condition was compared. We also examined the effect of IL-6 on the migration of HNSCC cells. Furthermore, to investigate the effect of fibroblast-derived IL-6 on the migration ability of HNSCC cells, we conducted a coculture study using IL-6 neutralizing antibody. RESULTS: Irradiation reduced the survival of HNSCC cells, whereas fibroblasts were resistant to irradiation. Irradiation also increased IL-6 secretion by fibroblasts. Migration of HNSCC cells was enhanced by coculture with fibroblasts and further enhanced by coculture with irradiated fibroblasts. We also confirmed that the migration of HNSCC cells was induced by IL-6. The enhanced migration of cancer cells caused by coculturing with fibroblasts was canceled by the IL-6 neutralizing antibody. CONCLUSION: These results show that fibroblasts survive irradiation and induce the migration ability of HNSCC cells through increased secretion of IL-6.

125I seeds inhibit proliferation and promote apoptosis in cholangiocarcinoma cells by regulating the AGR2-mediated p38 MAPK pathway.

125I seeds can effectively inhibit the growth of a variety of cancer cells. It has been used in the treatment of a variety of cancers, and has achieved certain curative effect. However, to the best of our knowledge, no report has described the effects of 125I seeds on the biological functions of cholangiocarcinoma (CCA) and the mechanisms underlying the effects of the seeds on this cancer. In this study, we demonstrated that 125I seeds could inhibit the proliferation, migration and invasion of CCA cells, as well as promoting apoptosis and blocking the cell cycle in these cells. Moreover, 125I seeds inhibited the growth of CCA xenografts and promoted the apoptosis of CCA cells in vivo. Furthermore, transcriptome sequencing showed that 125I seeds could inhibit the growth of CCA by inhibiting the expression of AGR2 and regulating p38 MAPK pathway. Finally, this finding indicated that 125I seeds can inhibit proliferation and promote apoptosis in CCA cells by inhibiting the expression of AGR2 and DUSP1 and increasing the expression of p-p38 MAPK and p-p53. This study provides a new research direction for studies investigating the mechanisms underlying the effects of 125I seeds on CCA.

AZD3759 enhances radiation effects in non-small-cell lung cancer by a synergistic blockade of epidermal growth factor receptor and Janus kinase-1.

AZD3759 is a novel epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) on the basis of gefitinib and has been proven to enter the central nervous system. Although the promising antitumor effects of AZD3759 on non-small cell lung cancer (NSCLC) have been demonstrated in clinical trials, the regulatory effects of this inhibitor on the antitumor efficacy of radiation (RA) are unclear. The present study aimed to compare the effects of AZD3759 and osimertinib on RA efficacy in NSCLC and explore the potential mechanism of action of AZD3759. We found that the survival in RA-treated NSCLC cells was significantly decreased by treatment with 500 nM AZD3759 and osimertinib at the RA dosage of 8 Gy. The apoptotic rate, cell cycle arrest, and DNA damage in RA-treated NSCLC cells and brain metastasis in RA-treated xenograft nude mice were significantly enhanced by the co-administration of AZD3759 and osimertinib, respectively. In addition, AZD3759 showed a significantly stronger efficacy than osimertinib did. Mechanistically, the receptor tyrosine kinase signaling antibody array revealed that Janus kinase-1 (JAK1) was specifically inhibited by AZD3759, but not by osimertinib. The effects of AZD3759 on RA efficacy in PC-9 cells and in a brain metastasis animal model were significantly abolished by the overexpression of JAK1. Collectively, our results suggested that AZD3759 promoted RA antitumor effects in NSCLC by synergistic blockade of EGFR and JAK1.