Narrow band imaging-based radiogenomics for predicting radiosensitivity in nasopharyngeal carcinoma

Objectives

This study aims to assess the efficacy of narrow band imaging (NBI) endoscopy in utilizing radiomics for predicting radiosensitivity in nasopharyngeal carcinoma (NPC), and to explore the associated molecular mechanisms.

Materials

The study included 57 NPC patients who were pathologically diagnosed and underwent RNA sequencing. They were categorized into complete response (CR) and partial response (PR) groups after receiving radical concurrent chemoradiotherapy. We analyzed 267 NBI images using ResNet50 for feature extraction, obtaining 2048 radiomic features per image. Using Python for deep learning and least absolute shrinkage and selection operator for feature selection, we identified differentially expressed genes associated with radiomic features. Subsequently, we conducted enrichment analysis on these genes and validated their roles in the tumor immune microenvironment through single-cell RNA sequencing.

Results

After feature selection, 54 radiomic features were obtained. The machine learning algorithm constructed from these features showed that the random forest algorithm had the highest average accuracy rate of 0.909 and an area under the curve of 0.961. Correlation analysis identified 30 differential genes most closely associated with the radiomic features. Enrichment and immune infiltration analysis indicated that tumor-associated macrophages are closely related to treatment responses. Three key NBI differentially expressed immune genes (NBI-DEIGs), namely CCL8, SLC11A1, and PTGS2, were identified as regulators influencing treatment responses through macrophages.

Conclusion

NBI-based radiomics models introduce a novel and effective method for predicting radiosensitivity in NPC. The molecular mechanisms may involve the functional states of macrophages, as reflected by key regulatory genes.

Prognostic model and ceRNA network of m7G- and radiosensitivity-related genes in hepatocellular carcinoma

Background

Radiotherapy is an effective treatment for hepatocellular carcinoma (HCC). Recent studies indicated that N7-methylguanosine (m7G)-associated genes are involved in radioresistance and prognosis of HCC. However, the prognostic value and underlying mechanism of m7G-and radiosensitivity-associated genes are still lacking.

Methods

The related statistics of HCC were downloaded from The Cancer Genome Atlas (TCGA). M7G- and radiosensitivity-associated genes were screened and evaluated using correlation, differential, univariate, and multivariate analysis. The least absolute shrinkage and selection operator (LASSO) algorithm was used to establish a prognostic model. Prognostic efficacy, functional analysis, immune cell infiltration,and drug sensitivity of the prognostic model were assessed. The ceRNA network was predicted and evaluated through the StarBase database, correlation analysis, expression analysis, and survival analysis.

Result

METTL1, EIF3D, NCBP2, and WDR4 participated in prognosis model construction. The favorable prediction efficiency has been verified in both the training and verification sets. Different risk groups have differences in prognosis outcome, function analysis, immune cell infiltration, and drug sensitivity. NCBP2 can be used to predict the prognosis and has excellent potential in immunotherapy. A prognostic ceRNA network based on the NCBP2/miR-122-5p axis was established.

Conclusion

The prognosis model of m7G- and radiosensitivity-related genes is constructed, and widely used in clinical prognosis, immunotherapy, and drug therapy. NCBP2, as a hub gene, may be a prognostic biomarker for HCC and is related to immunotherapy. Establishing the NCBP2/miR-122-5p axis helps study the mechanism of ceRNA and provides new ideas for finding a new candidate biomarker.

Radiosensitizing effects of heparinized magnetic iron oxide nanoparticles in colon cancer

The combination of radiation treatment and chemotherapy is currently the standard for management of cancer patients. However, safe doses do not often provide effective therapy, then pre-treated patients are forced to repeat treatment with often already increased tumor resistance to drugs and irradiation. One of the solutions we suggest is to improve primary course of radiation treatment via enhancing radiosensitivity of tumors by magnetic-guided iron oxide nanoparticles (magnetite). We obtained spherical heparinized iron oxide nanoparticles (hIONPs, ∼20 nm), characterized it by TEM, Infrared spectroscopy and DLS. Then hIONPs cytotoxicity was assessed for colon cancer cells (XTT assay) and cellular uptake of nanoparticles was analyzed with X-ray fluorescence. Combination of ionizing radiation (IR) and hIONPs in vitro caused an increase of G2/M arrest of cell cycle, mitotic errors and decrease in survival (compared with samples exposed to IR and hIONPs separately). The promising results were shown for magnetic-guided hIONPs in CT26-grafted BALB/C mice: the combination of intravenously administrated hIONPs and IR showed 20,8% T/C ratio (related to non-treated mice), while single radiation had no shown significant decrease in tumor growth (72,4%). Non-guided by magnets hIONPs with IR showed 57,9% of T/C. This indicates that ultra-small size and biocompatible molecule are not the key to successful nano-drug design, in each case, delivery technologies need to be improved when transferred to in vivo model.

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.

Uncovering a novel DNA repair-related radiosensitivity model for evaluation of radiotherapy susceptibility in uterine corpus endometrial cancer

Background

Uterine corpus endometrial cancer (UCEC) exhibit heterogeneity in their DNA repair capacity, which can impact their response to radiotherapy. Our study aimed to identify potential DNA repair-related biomarkers for predicting radiation response in UCEC.

Methods

We conducted a thorough analysis of 497 UCEC samples obtained from TCGA database. Using LASSO-COX regression analysis, we constructed a radiosensitivity signature and subsequently divided patients into the radiosensitive (RS) and the radioresistant (RR) groups based on their radiosensitivity index. The GSVA and GSEA were performed to explore functional annotations. The CIBERSORT and ESTIMATE algorithms were utilized to investigate the immune infiltration status of the two groups. Additionally, we utilized the Tumor Immune Dysfunction and Exclusion (TIDE), Immunophenotype Score (IPS), and pRRophetic algorithms to predict the effectiveness of different treatment modalities.

Results

We constructed a radiosensitivity index consists of four DNA repair-related genes. Patients in the RS group demonstrated significantly improved prognosis compared to patients in the RR group when treated with radiotherapy. We observed that the RS group exhibited a higher proportion of the POLE ultra-mutated subtype, while the RR group had a higher proportion of the copy number high subtype. GSVA enrichment analysis revealed that the RS group exhibited enrichment in DNA damage repair pathways. Notably, the RS group demonstrated a higher proportion of naïve B cells and follicular helper T cells, while regulatory T cells (Tregs) and memory B cells were more abundant in the RR group. Furthermore, patients in the RS-PD-L1-high subgroup exhibited enrichment in immune-related pathways and increased sensitivity to immunotherapy, which is likely to contribute to their improved prognosis. Additionally, we conducted in vitro experiments to validate the expression of radiosensitivity genes in non-radioresistant (AN3CA) and radioresistant (AN3CA/IR) endometrial cancer cells.

Conclusions

In conclusion, our research successfully constructed a radiosensitivity signature with robust predictive capacity. These findings shed light on the association between immune activation, PD-L1 expression, and the response to immunotherapy in the context of radiotherapy.

Mogrol-Mediated enhancement of radiotherapy sensitivity in Non-Small cell lung cancer: A mechanistic study

OBJECTIVE

Investigate Mogrol's impact on NSCLC radiosensitivity and underlying mechanisms using various methods including assays, bioinformatics, and xenograft models.

METHODS

CCK-8, clonogenic, flow cytometry, TUNEL, and Western blot assays evaluated Mogrol and radiation effects on NSCLC viability and apoptosis. USP22 expression in NSCLC patient tissues was determined using RT-qPCR and Western blot. A xenograft model validated Mogrol's effects on tumor growth.

RESULTS

Bioinformatics identified four ubiquitin-specific proteases, including USP22, in NSCLC. Kaplan-Meier analysis confirmed USP22's value in lung cancer survival. HPA database indicated higher USP22 expression in lung cancer tissues. GO and KEGG analysis implicated ERK1/2 in NSCLC progression, and molecular docking showed stability between Mogrol and ERK1/2. Further in vivo and in vitro experiments have demonstrated that Mogrol enhances the inhibitory effect of radiation on NSCLC cell viability and clonogenic capacity. Cell viability and clonogenic capacity are reduced by more than 50%, and an increase in cellular apoptosis is observed, with apoptotic levels reaching 10%. USP22 expression was significantly elevated in NSCLC tissues, particularly in radiotherapy-resistant patients. Mogrol downregulated USP22 expression by inhibiting the ERK/CREB pathway, lowering COX2 expression. Mogrol also enhanced radiation's inhibition of tumor growth in mice.

CONCLUSION

Mogrol enhances NSCLC radiosensitivity by downregulating USP22 via the ERK/CREB pathway, leading to reduced COX2 expression.

DNA-dependent protein kinase regulates cytosolic double-stranded DNA secretion from irradiated macrophages to increase radiosensitivity of tumors

BACKGROUND AND PURPOSE

To investigate the molecular mechanism by which irradiated macrophages secrete cytosolic double-stranded DNA (c-dsDNA) to increase radiosensitivity of tumors.

MATERIALS AND METHODS

Irradiated bone marrow-derived macrophages (BMDM) were co-incubated with irradiated EO771 or MC38 cancer cells to determine clonogenic survival. c-dsDNA were measured by agarose gel or enzyme-linked immunosorbent assay. BMDM or cancer cells were analyzed with immunostaining or western blot. Subcutaneously implanted MC38 cells in myeloid-specific Prkdc knockout (KO) mice or littermate control mice were irradiated with 8 Gy to determine radiosensitivity of tumors.

RESULTS

We observed that irradiated BMDM significantly increased radiosensitivity of cancer cells. By performing immunostaining, we found that there was a dose-dependent increase in the formation of c-dsDNA and phosphorylation in DNA-dependent protein kinase (DNA-PK) in irradiated BMDM. Importantly, c-dsDNA in irradiated BMDM could be secreted to the extracellular milieu and this process required DNA-PK, which phosphorylated myosin light chain to regulate the secretion. The secreted c-dsDNA from irradiated BMDM then activated toll-like receptor-9 and subsequent nuclear factor kappa-light-chain-enhancer of activated B cells signaling in the adjacent cancer cells inhibiting radiation-induced DNA double strand break repair. Lastly, we observed that irradiated tumors in vivo had a significantly increased number of tumor-associated macrophages (TAM) with phosphorylated DNA-PK expression in the cytosol. Furthermore, tumors grown in myeloid-specific Prkdc KO mice, in which TAM lacked phosphorylated DNA-PK expression were significantly more radioresistant than those of the wild-type control mice.

CONCLUSIONS

Irradiated macrophages can increase antitumor efficacy of radiotherapy through secretion of c-dsDNA under the regulation of DNA-PK.

CircNOP14 increases the radiosensitivity of hepatocellular carcinoma via inhibition of Ku70-dependent DNA damage repair

Circular RNAs (circRNAs) are profoundly affected in hepatocellular carcinoma (HCC) through various pathways. However, the role of circRNAs in the radiosensitivity of HCC cells is yet to be explored. In this study, we identified a circRNA-hsa_circ_0006737 (circNOP14) involved in the radiosensitivity of HCC. We found that circNOP14 increased the radiosensitivity of HCC cells both in vitro and in vivo. Notably, using a circRNA pulldown assay and RNA-binding protein immunoprecipitation, we identified Ku70 as a novel and robust interacting protein of circNOP14. Mechanistically, circNOP14 interacts with Ku70 and prevents its nuclear translocation, thereby increasing irradiation-induced DNA damage. Therefore, our findings may provide a predictive indicator and intervention option for 125I brachytherapy or external radiotherapy in HCC.

Exosome miR-101-3p derived from bone marrow mesenchymal stem cells promotes radiotherapy sensitivity in non-small cell lung cancer by regulating DNA damage repair and autophagy levels through EZH2

BACKGROUND AND OBJECTIVE

The morbidity rate of non-small cell lung cancer (NSCLC) increases with age, highlighting that NSCLC is a serious threat to human health. The aim of this study was mainly to describe the role of exosomal miR-101-3p derived from bone marrow mesenchymal stem cells (BMSCs) in NSCLC.

METHODS

A549 or NCI-H1703 cells (1×105/mouse) were injected into nude mice to establish an NSCLC animal model. RTqPCR, Western blotting and comet assays were used to assess the changes in gene expression, proteins and DNA damage repair.

RESULTS

miR-101-3p and RAI2 were found to be expressed at low levels in NSCLC, while EZH2 was highly expressed. In terms of function, miR-101-3p downregulated EZH2. In addition, exosomal miR-101-3p derived from BMSCs promoted the expression of RAI2, inhibited DNA damage repair, and inhibited the activation of the PI3K/AKT/mTOR signaling pathway by inhibiting EZH2, thereby promoting autophagy and decreasing cell viability and finally enhancing the sensitivity of NSCLC to radiotherapy and inhibiting the malignant biological behavior of NSCLC.

CONCLUSION

Exosomal miR-101-3p derived from BMSCs can inhibit DNA damage repair, promote autophagy, enhance the radiosensitivity of NSCLC, and inhibit the progression of NSCLC by inhibiting EZH2.

Hsa-miR-92b-3p Targeting FHL2 to Enhance Radiosensitivity of Nasopharyngeal Carcinoma

Radiotherapy resistance is a major cause of treatment failure and leads to poor prognosis in nasopharyngeal carcinoma (NPC). Evidences indicate that microRNA (miRNAs) are closely associated with radiotherapy for NPC. In this study, we found that the expression level of miR-92b-3p was significantly higher in radiotherapy-sensitive NPC patients than in radiotherapy-resistant patients. High expression of miR-92b-3p was associated with good prognosis in patients with NPC, and high expression of FHL2 was associated with poor prognosis in patients with NPC. It was predicted that miR-92b-3p could directly target and bind FHL2. Overexpression of miR-92b-3p significantly inhibited FHL2 expression at the mRNA as well as protein levels, while inhibition of miR-92b-3p expression significantly upregulated FHL2 expression. Overexpression of miR-92b-3p significantly reduced proliferation and colony formation in NPC cells. Inhibition of miR-92b-3p attenuated the sensitivity of nasopharyngeal carcinoma to radiotherapy, while simultaneous inhibition of miR-92b-3p and FHL2 increased the sensitivity of NPC to radiotherapy. Our findings highlighted that miR-92b-3p is closely associated with radiotherapy sensitivity and prognosis in NPC patients and may improve the sensitivity of NPC to radiotherapy by targeting FHL2.

Single-cell transcriptomic sequencing data reveal aberrant DNA methylation in SMAD3 promoter region in tumor-associated fibroblasts affecting molecular mechanism of radiosensitivity in non-small cell lung cancer

OBJECTIVE

Non-small cell lung cancer (NSCLC) often exhibits resistance to radiotherapy, posing significant treatment challenges. This study investigates the role of SMAD3 in NSCLC, focusing on its potential in influencing radiosensitivity via the ITGA6/PI3K/Akt pathway.

METHODS

The study utilized gene expression data from the GEO database to identify differentially expressed genes related to radiotherapy resistance in NSCLC. Using the GSE37745 dataset, prognostic genes were identified through Cox regression and survival analysis. Functional roles of target genes were explored using Gene Set Enrichment Analysis (GSEA) and co-expression analyses. Gene promoter methylation levels were assessed using databases like UALCAN, DNMIVD, and UCSC Xena, while the TISCH database provided insights into the correlation between target genes and CAFs. Experiments included RT-qPCR, Western blot, and immunohistochemistry on NSCLC patient samples, in vitro studies on isolated CAFs cells, and in vivo nude mouse tumor models.

RESULTS

Fifteen key genes associated with radiotherapy resistance in NSCLC cells were identified. SMAD3 was recognized as an independent prognostic factor for NSCLC, linked to poor patient outcomes. High expression of SMAD3 was correlated with low DNA methylation in its promoter region and was enriched in CAFs. In vitro and in vivo experiments confirmed that SMAD3 promotes radiotherapy resistance by activating the ITGA6/PI3K/Akt signaling pathway.

CONCLUSION

High expression of SMAD3 in NSCLC tissues, cells, and CAFs is closely associated with poor prognosis and increased radiotherapy resistance. SMAD3 is likely to enhance radiotherapy resistance in NSCLC cells by activating the ITGA6/PI3K/Akt signaling pathway.

Compound Taxus exerts marked anti-tumor activity and radiosensitization effect on hepatocellular carcinoma cells

Background

Compound Taxus capsule, as an antineoplastic Chinese patent drug, has been increasingly applied as an adjunctive treatment for the management of non-small-cell lung cancer (NSCLC) and some other malignancies, but research about its antitumor activity and radiosensitization effect on hepatocellular carcinoma (HCC) cells is very rare.

Purpose

To investigate the antitumor activity and radiosensitization effect of Compound Taxus on HCC cells and to preliminarily explore the possible molecule mechanisms involved.

Methods

Cell viability, cell cycle distribution, apoptosis, DNA damage repair and protein expression levels were detected by CCK-8 assay, flow cytometry, immunofluorescence staining, western blotting analysis and immunohistochemical staining, respectively. The migration and invasion activities and vasculogenic mimicry (VM) formation and angiogenesis were evaluated by tube formation and VM formation assay. Radiation survival curves were obtained from the colony formation assay in human HCC cell lines, Smmc7721 and Bel7402 cells, pretreated with or without Compound Taxus before receiving X-ray irradiation. A Bel7402 tumor-bearing mouse model was established and the radiosensitization effect of Compound Taxus in vivo was evaluated by analyzing tumor volume and tumor weight in different groups receiving different treatments.

Results

Compound Taxus decreased viability, induced G2/M arrest, promoted apoptosis, suppressed migration and invasion, and inhibited VM formation and angiogenesis in Smmc7721 and Bel7402 cells. Furthermore, Compound Taxus inhibited irradiation-induced DNA damage repair, enhanced the radiosensitivity of Smmc7721 and Bel7402 cells and improved the anti-tumor therapeutic efficacy of irradiation in Bel7402 tumor-bearing mice. Radiotherapy in combination with Compound Taxus showed the best tumor inhibition compared to that of Compound Taxus alone or irradiation alone. In addition, Compound Taxus significantly down-regulated NF-κB p65, p-NF-κB p65 and Bcl-2, and up-regulated Bax in vitro and in vivo, yet NF-κB p65 overexpression reversed the proapoptotic effect of Taxus on HCC cells, indicating that the NF-κB signaling pathway might be an important signal mediator in the Compound-Taxus-modulated biological responses.

Conclusion

Our findings suggest that Compound Taxus shows marked antitumor activity and significant radiosensitization effect on HCC cells, making it possible for Compound Taxus to become a promising auxiliary modality for HCC management and a potential radiosensitizer of HCC in the future.

Long non-coding RNA CCAT1 acts as an oncogene to promote radiation resistance in lung adenocarcinoma: an epigenomics-based investigation

Long non-coding RNAs (lncRNAs) appear to be the crucial modulators in various processes and critically influence the oncogenesis. As one of the LncRNAs, LncRNA CCAT1 has been reported to be closely associated with the progression multiple cancers, but its role in modulating the radioresistance of lung adenocarcinoma (LUAD) remains unclear. In our present study, we screened the potential radioresistance related LncRNAs in LUAD based on the data from The Cancer Genome Atlas (TCGA) database. Data suggested that CCAT1 was abundantly expressed in LUAD and CCAT1 was significantly associated with poor prognosis and radioresistance. Moreover, our in vitro experiments showed that radiation treatment could trigger elevated expression of CCAT1 in the human LUAD cell lines. Further loss/gain-of-function investigations indicated that CCAT1 knockdown significantly inhibited cell proliferation, migration and promoted cell apoptosis in NCI-H1299 cells under irradiation, whereas CCAT1 overexpression in A549 cells yield the opposite effects. In summary, we identified the promoting role of CCAT1 in radioresistance of LUAD, which may provide a theoretical basis for radiotherapy sensitization of LUAD.

Silencing PinX1 enhances radiosensitivity and antitumor-immunity of radiotherapy in non-small cell lung cancer

BACKGROUND

We aimed to investigate the effects of PinX1 on non-small cell lung cancer(NSCLC) radiosensitivity and radiotherapy-associated tumor immune microenvironment and its mechanisms.

METHODS

The effect of PinX1 silencing on radiosensitivity in NSCLC was assessed by colony formation and CCK8 assay, immunofluorescence detection of γ- H2AX and micronucleus assay. Western blot was used to assess the effect of PinX1 silencing on DNA damage repair pathway and cGAS-STING pathway. The nude mouse and Lewis lung cancer mouse model were used to assess the combined efficacy of PinX1 silencing and radiotherapy in vivo. Changes in the tumor immune microenvironment were assessed by flow cytometry for different treatment modalities in the Lewis luuse model. The interaction protein RBM10 was screened by immunoprecipitation-mass spectrometry.

RESULTS

Silencing PinX1 enhanced radiosensitivity and activation of the cGAS-STING pathway while attenuating the DNA damage repair pathway. Silencing PinX1 further increases radiotherapy-stimulated CD8+ T cell infiltration and activation, enhances tumor control and improves survival in vivo; Moreover, PinX1 downregulation improves the anti-tumor efficacy of radioimmunotherapy, increases radioimmune-stimulated CD8+ T cell infiltration, and reprograms M2-type macrophages into M1-type macrophages in tumor tissues. The interaction of PinX1 and RBM10 may promote telomere maintenance by assisting telomerase localization to telomeres, thereby inhibiting the immunostimulatory effects of IR.

CONCLUSIONS

In NSCLC, silencing PinX1 significantly contributed to the radiosensitivity and promoted the efficacy of radioimmunotherapy. Mechanistically, PinX1 may regulate the transport of telomerase to telomeres through interacting with RBM10, which promotes telomere maintenance and DNA stabilization. Our findings reveal that PinX1 is a potential target to enhance the efficacy of radioimmunotherapy in NSCLC patients.

Induction sintilimab and chemotherapy followed by concurrent chemoradiotherapy for locally advanced esophageal cancer: a proof-of-concept, single-arm, multicenter, phase 2 trial

Background

Concurrent chemoradiotherapy is the standard nonoperative treatment for locally advanced esophageal squamous cell carcinoma. However, local recurrence is still the main failure pattern, accounting for more than half of all treatment failures, indicating that the sensitivity of radiotherapy still needs to be improved. This trial aimed at demonstrating whether PD-1 inhibitors followed by chemoradiotherapy could promote esophageal tumor vascular normalization, alleviate hypoxia, and thus enhance radiosensitivity and improve local control.

Methods

We did a multicenter, single-arm, phase 2 trial in China. Patients with locally advanced esophageal cancer were enrolled in this study. In induction phase, patients received two cycles of sintilimab, paclitaxel and carboplatin once per 21 days. In concurrent phase, patients were treated with five cycles of carboplatin and paclitaxel once per week concurrent with radiotherapy of 50.4Gy delivered in 28 fractions. The primary endpoint was 2-year local control rate. Hypoxia and vessel normalization was assessed before and after induction phase using immunofluorescence and perfusion CT. This trial is registered with ClinicalTrials.gov (NCT03985046).

Findings

Seventy-five patients with esophageal cancer were enrolled in this study between October 2019 and April 2021. The median follow-up of surviving patients was 33.6 months (IQR 29.3-35.7). The 2-year local control rate was 81.7% (95% confidence interval, 72.7%-90.7%), which was much higher than that in concurrent chemoradiation only (71.3%) in previous studies. Vascular normalization and hypoxia alleviation were observed in both biopsy specimens and perfusion CT.

Interpretation

The addition of induction immunotherapy to standard concurrent chemoradiotherapy could improve radiosensitivity for locally advanced esophageal cancer as non-surgical treatment. New treatment combination led to higher local control rate through promoting vascular normalization and alleviating hypoxia. Our findings suggest that induction immunotherapy followed by concurrent chemoradiotherapy could be a potential option in future treatment.

Funding

National Natural Science Foundation of China and Shanghai Rising-Star Program.

Effect of bisphosphonates and statins on the in vitro radiosensitivity of breast cancer cell lines

BACKGROUND

Early-stage breast cancer is usually treated with breast-conserving surgery followed by adjuvant radiation therapy. Acute skin toxicity is a common radiation-induced side effect experienced by many patients. Recently, a combination of bisphosphonates (zoledronic acid) and statins (pravastatin), or ZOPRA, was shown to radio-protect normal tissues by enhancing DNA double-strand breaks (DSB) repair mechanism. However, there are no studies assessing the effect of ZOPRA on cancerous cells. The purpose of this study is to characterize the in vitro effect of the zoledronic acid (ZO), pravastatin (PRA), and ZOPRA treatment on the molecular and cellular radiosensitivity of breast cancer cell lines.

MATERIALS

Two breast cancer cell lines, MDA MB 231 and MCF-7, were tested. Cells were treated with different concentrations of pravastatin (PRA), zoledronate (ZO), as well as their ZOPRA combination, before irradiation. Anti-γH2AX and anti-pATM immunofluorescence were performed to study DNA DSB repair kinetics. MTT assay was performed to assess cell proliferation and viability, and flow cytometry was performed to analyze the effect of the drugs on the cell cycle distribution. The clonogenic assay was used to assess cell survival.

RESULTS

ZO, PRA, and ZOPRA treatments were shown to increase the residual number of γH2AX foci for both cell lines. ZOPRA treatment was also shown to reduce the activity of the ATM kinase in MCF-7. ZOPRA induced a significant decrease in cell survival for both cell lines.

CONCLUSIONS

Our findings show that pretreatment with ZOPRA can decrease the radioresistance of breast cancer cells at the molecular and cellular levels. The fact that ZOPRA was previously shown to radioprotect normal tissues, makes it a good candidate to become a therapeutic window-widening drug.

Persons chronically exposed to low doses of ionizing radiation: A cytogenetic dosimetry study

The dosimetry and control of exposure for individuals chronically exposed to ionizing radiation are important and complex issues. Assessment may be optimized by evaluating individual adaptation and radiosensitivity, but it is not possible for a single model to account for all relevant parameters. Our goal was to develop approaches for the calculation of doses for persons chronically exposed to ionizing radiation, taking their radiosensitivities into consideration. On the basis of ex vivo radiation of blood samples, dose-effect models were constructed for dose ranges 0.01-2.0 and 0.01-0.4 Gy, using different cytogenetic criteria. The frequencies of "dicentric chromosomes and rings" at low doses are too low to have predictive value. The different responses of subjects to radiation made it possible to categorize them according to their radiosensitivities and to generate separate dose-effect curves for radiosensitive, average, and radioresistant individuals, reducing the amount of error in retrospective dosimetry.

The value of subcutaneous xenografts for individualised radiotherapy in HNSCC: Robust gene signature correlates with radiotherapy outcome in patients and xenografts

PURPOSE

To assess the robustness of prognostic biomarkers and molecular tumour subtypes developed for patients with head and neck squamous cell carcinoma (HNSCC) on cell-line derived HNSCC xenograft models, and to develop a novel biomarker signature by combining xenograft and patient datasets.

MATERIALS AND METHODS

Mice bearing xenografts (n = 59) of ten HNSCC cell lines and a retrospective, multicentre patient cohort (n = 242) of the German Cancer Consortium-Radiation Oncology Group (DKTK-ROG) were included. All patients received postoperative radiochemotherapy (PORT-C). Gene expression analysis was conducted using GeneChip Human Transcriptome Arrays. Xenografts were stratified based on their molecular subtypes and previously established gene classifiers. The dose to control 50 % of tumours (TCD50) was compared between these groups. Using differential gene expression analyses combining xenograft and patient data, a gene signature was developed to define risk groups for the primary endpoint loco-regional control (LRC).

RESULTS

Tumours of mesenchymal subtype were characterized by a higher TCD50 (xenografts, p < 0.001) and lower LRC (patients, p < 0.001) compared to the other subtypes. Similar to previously published patient data, hypoxia- and radioresistance-related gene signatures were associated with high TCD50 values. A 2-gene signature (FN1, SERPINE1) was developed that was prognostic for TCD50 (xenografts, p < 0.001) and for patient outcome in independent validation (LRC: p = 0.007).

CONCLUSION

Genetic prognosticators of outcome for patients after PORT-C and subcutaneous xenografts after primary clinically relevant irradiation show similarity. The identified robust 2-gene signature may help to guide patient stratification, after prospective validation. Thus, xenografts remain a valuable resource for translational research towards the development of individualized radiotherapy.

The dual role of autophagy in HPV-positive head and neck squamous cell carcinoma: a systematic review

PURPOSE

Human papilloma virus (HPV)-positive head and neck squamous cell carcinoma (HNSCC) displays distinct epidemiological, clinical, and molecular characteristics compared to the negative counterpart. Alterations in autophagy play an important role in cancer, and emerging evidence indicates an interplay of autophagy in HNSCC carcinogenesis and tumor promotion. However, the influence of HPV infection on autophagy in HNSCC has received less attention and has not been previously reviewed. Therefore, we here aimed to systematically review the role of autophagy explicitly in HPV+ HNSCC.

METHODS

Studies accessible in PubMed, Embase, Scopus, and Web of Science investigating HNSCC, highlighting the molecular biological differences between HPV- and HPV+ HNSCC and its influences on autophagy in HNSCC were analyzed according to the PRISMA statement. A total of 10 articles were identified, included, and summarized.

RESULTS

The HPV16 E7 oncoprotein was reported to be involved in the degradation of AMBRA1 and STING, and to enhance chemotherapy-induced cell death via lethal mitophagy in HNSCC cells. Autophagy-associated gene signatures correlated with HPV-subtype and overall survival. Additionally, immunohistochemical (IHC) analyses indicate that high LC3B expression correlates with poor overall survival in oropharyngeal HNSCC patients.

CONCLUSION

HPV may dampen general bulk autophagic flux via degradation of AMBRA1 but may promote selective autophagic degradation of STING and mitochondria. Interpretations of correlations between autophagy-associated gene expressions or IHC analyses of autophagy-related (ATG) proteins in paraffin embedded tissue with clinicopathological features without biological validation need to be taken with caution.

The mir-199b-5p encapsulated in adipocyte-derived exosomes mediates radioresistance of colorectal cancer cells by targeting JAG1

Radiotherapy is a key treatment option for colorectal cancer, but its efficacy varies among patients. Our previous studies suggested that adipose tissue may confer the radioresistance of several abdominal tumors, such as pancreatic cancer, biliary cancer, and others. In the present work, the effects of adipocytes in regulating the radiosensitivity of colorectal cancer are explored for the first time. It was found that colony formation was increased and radiation-induced apoptosis decreased in colorectal cancer cells HCT8 and HCT116 co-cultured with adipocytes, which verified the mediation of adipocyte-driven radioresistance in colorectal cancer in vitro. Next, the colorectal cancer cells were incubated with adipocyte-derived exosomes, and a perceptible reduction in radiosensitivity was detected. Furthermore, to investigate the possible mechanisms involved, the exosomes were isolated, the encapsulated microRNAs were extracted and analyzed by small RNA sequencing. Based on bioinformatics analysis and qRT-PCR verification, miR-199b-5p was chosen for functional annotation. It was shown that miR-199b-5p expression was significantly upregulated after 6 Gy irradiation, and overexpressed miR-199b-5p significantly suppressed the radiosensitivity of HCT8 and HCT116 cells. In addition, jagged canonical Notch ligand 1(JAG1) was identified as the target gene of miR-199b-5p by using bioinformatics prediction and dual luciferase reporter gene assay. It was demonstrated that JAG1 conferred the radioresistance of colorectal cancer cells both in vivo and in vitro. Taken together, the present study demonstrates that adipocytes trigger the radioresistance of colorectal cancer cells, probably by targeting JAG1 through an adipocyte-derived exosomal miR-199b-5p.

Mitophagy plays a "double-edged sword" role in the radiosensitivity of cancer cells

Mitochondria are organelles with double-membrane structure of inner and outer membrane, which provides main energy support for cell growth and metabolism. Reactive oxygen species (ROS) mainly comes from mitochondrial and can cause irreversible damage to cells under oxidative stress. Thus, mitochondrial homeostasis is the basis for maintaining the normal physiological function of cells and mitophagy plays a pivotal role in the maintenance of mitochondrial homeostasis. At present, to enhance the sensitivity of cancer cells to radiotherapy and chemotherapy by regulating mitochondria has increasingly become a hot spot of cancer therapy. It is particularly important to study the effect of ionizing radiation (IR) on mitochondria and the role of mitophagy in the radiosensitivity of cancer cells. Most of the existing reviews have focused on mitophagy-related molecules or pathways and the impact of mitophagy on diseases. In this review, we mainly focus on discussing the relationship between mitophagy and radiosensitivity of cancer cells around mitochondria and IR.

Dynamic analysis of predictive biomarkers for radiation therapy efficacy in non-small cell lung cancer patients by next-generation sequencing based on blood specimens

PURPOSE

Radiotherapy plays an important role in the treatment of non-small cell lung cancer, and the aim of this study was to explore the potential association of single gene mutation or pathway mutations with radiotherapy response using targeted next-generation sequencing (NGS) testing of peripheral blood specimens.

MATERIAL AND METHODS

We performed NGS containing 425 genes on peripheral blood specimens from 13 NSCLC patients pre- and post-radiotherapy or post-radiotherapy. Patients whose tumors were in complete response or partial response within 1 month after radiotherapy were classified as a radiotherapy-sensitive group; otherwise, they were categorized as a radiotherapy-resistant group. The relationship between single gene mutations, signaling pathway mutations, dynamic fluctuations in circulating tumor DNA （ctDNA）, and radiotherapy response was investigated.

RESULTS

Of these 13 patients，6 patients were categorized as a radiotherapy-sensitive group (46.2%), and 7 patients were categorized as a radiotherapy-resistant group (53.8%). No correlation between single gene mutations and response to radiotherapy. Mutations in the SWI/SNF complex were more likely to occur in the radiotherapy-sensitive group than in the other group (p = 0.07). Among all patients，9 patients underwent NGS tests pre- and post-radiotherapy. Dynamic analysis based on ctDNA before and after treatment revealed that a decrease in ctDNA abundance was observed in all patients in the radiotherapy-sensitive group.

CONCLUSIONS

SWI/SNF complex mutations may be potential predictive biomarkers of radiotherapy response. Decreased ctDNA abundance after radiotherapy correlates with better efficacy of radiotherapy.

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.

Tumor-specific radiosensitizing effect of the ATM inhibitor AZD0156 in melanoma cells with low toxicity to healthy fibroblasts

PURPOSE

Despite new treatment options, melanoma continues to have an unfavorable prognosis. DNA damage response (DDR) inhibitors are a promising drug class, especially in combination with chemotherapy (CT) or radiotherapy (RT). Manipulating DNA damage repair during RT is an opportunity to exploit the genomic instability of cancer cells and may lead to radiosensitizing effects in tumors that could improve cancer therapy.

METHODS

A panel of melanoma-derived cell lines of different origin were used to investigate toxicity-related clonogenic survival, cell death, and cell cycle distribution after treatment with a kinase inhibitor (KI) against ATM (AZD0156) or ATR (VE-822, berzosertib), irradiation with 2 Gy, or a combination of KI plus ionizing radiation (IR). Two fibroblast cell lines generated from healthy skin tissue were used as controls.

RESULTS

Clonogenic survival indicated a clear radiosensitizing effect of the ATM inhibitor (ATMi) AZD0156 in all melanoma cells in a synergistic manner, but not in healthy tissue fibroblasts. In contrast, the ATR inhibitor (ATRi) VE-822 led to additive enhancement of IR-related toxicity in most of the melanoma cells. Both inhibitors mainly increased cell death induction in combination with IR. In healthy fibroblasts, VE-822 plus IR led to higher cell death rates compared to AZD0156. A significant G2/M block was particularly induced in cancer cells when combining AZD0156 with IR.

CONCLUSION

ATMi, in contrast to ATRi, resulted in synergistic radiosensitization regarding colony formation in melanoma cancer cells, while healthy tissue fibroblasts were merely affected with respect to cell death induction. In connection with an increased number of melanoma cells in the G2/M phase after ATMi plus IR treatment, ATMi seems to be superior to ATRi in melanoma cancer cell treatments when combined with RT.

Copper homeostasis and cuproptosis in mitochondria

Mitochondria serve as sites for energy production and are essential for regulating various forms of cell death induced by metal metabolism, targeted anticancer drugs, radiotherapy and immunotherapy. Cuproptosis is an autonomous form of cell death that depends on copper (Cu) and mitochondrial metabolism. Although the recent discovery of cuproptosis highlights the significance of Cu and mitochondria, there is still a lack of biological evidence and experimental verification for the underlying mechanism. We provide an overview of how Cu and cuproptosis affect mitochondrial morphology and function. Through comparison with ferroptosis, similarities and differences in mitochondrial metabolism between cuproptosis and ferroptosis have been identified. These findings provide implications for further exploration of cuproptotic mechanisms. Furthermore, we explore the correlation between cuproptosis and immunotherapy or radiosensitivity. Ultimately, we emphasize the therapeutic potential of targeting cuproptosis as a novel approach for disease treatment.

CDC20 promotes radioresistance of prostate cancer by activating Twist1 expression

Currently, radiotherapy is one of the most attractive treatments for prostate cancer (PCa) patients. However, radioresistance remains a challenging issue and the underlying mechanism is unknown. Growing evidence has demonstrated that CDC20 (Cell division cycle protein 20) plays a pivotal role in a variety of tumors, including PCa. Here, GEPIA database mining and western blot analysis showed that higher expression of CDC20 was observed in PCa tissues and cells. We demonstrated that the expression of CDC20 was increased in PCa cells by irradiation, and knockdown of CDC20 resulted in inhibition of cell proliferation, migration, tumor formation, induced cell apoptosis and increased radiosensitivity in PCa in vitro and in vivo. Furthermore, we observed that CDC20 regulated Twist1 pathway, influencing cell proliferation and migration. These results suggest that targeting CDC20 and Twist1 may be an effective way to improve the radiosensitivity of PCa.

Research on radiotherapy related genes and prognostic target identification of rectal cancer based on multi-omics

BACKGROUND

Radiosensitivity of rectal cancer is related to the radiotherapy efficacy and prognosis of patients with rectal cancer, and the genes and molecular mechanisms related to radiosensitivity of rectal cancer have not been clarified. We explored the radiosensitivity related genes of rectal cancer at a multi omics level.

METHODS

mRNA expression data and rectum adenocarcinoma (READ) data were obtained from the Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus Database (GEO) (GSE150082, GSE60331, GSE46862, GSE46862). Differentially expressed genes between radiotherapy sensitive group and radiotherapy insensitive group were screened. GO analysis and KEGG pathway analysis were performed for differentially expressed genes. Among the differentially expressed genes, five core genes associated with rectal cancer prognosis were selected using random survival forest analysis. For these five core genes, drug sensitivity analysis, immune cell infiltration analysis, TISIDB database immune gene correlation analysis, GSEA enrichment analysis, construction of Nomogram prediction model, transcriptional regulatory network analysis, and qRT-PCR validation was performed on human rectal adenocarcinoma tissue.

RESULTS

We found that 600 up-regulated genes and 553 down-regulated genes were significantly different between radiotherapy sensitive group and radiotherapy insensitive group in rectal cancer. Five key genes, TOP2A, MATR3, APOL6, JOSD1, and HOXC6, were finally screened by random survival forest analysis. These five key genes were associated with different immune cell infiltration, immune-related genes, and chemosensitivity. A comprehensive transcriptional regulatory network was constructed based on these five core genes. qRT-PCR revealed that MATR3 expression was different in rectal cancer tissues and adjacent non-cancerous tissues, while APOL6, HOXC6, JOSD1, and TOP2A expression was not different.

CONCLUSION

Five radiosensitivity-related genes related to the prognosis of rectal cancer: TOP2A, MATR3, APOL6, JOSD1, HOXC6, are involved in multiple processes such as immune cell infiltration, immune-related genes, chemosensitivity, signaling pathways and transcriptional regulatory networks and may be potential biomarkers for radiotherapy of rectal cancer.

Enhancing nasopharyngeal carcinoma cell radiosensitivity by suppressing AKT/mTOR via CENP-N knockdown

OBJECTIVE

Investigating the impact of centromere protein N (CENP-N) on radiosensitivity of nasopharyngeal carcinoma (NPC) cells.

METHODS

Using immunohistochemistry and immunofluorescence to detect CENP-N expression in tissues from 35 patients with radiosensitive or radioresistant NPC. Assessing the effect of combined CENP-N knockdown and radiotherapy on various cellular processes by CCK-8, colony formation, flow cytometry, and Western blotting. Establishing a NPC xenograft model. When the tumor volume reached 100 mm3, a irradiation dose of 6 Gy was given, and the effects of the combined treatment were evaluated in vivo using immunofluorescence and Western blotting techniques.

RESULTS

The level of CENP-N was significantly reduced in radiosensitive tissues of NPC (p < 0.05). Knockdown of CENP-N enhanced NPC radiosensitivity, resulting in sensitizing enhancement ratios (SER) of 1.44 (5-8 F) and 1.16 (CNE-2Z). The combined treatment showed significantly higher levels of proliferation suppression, apoptosis, and G2/M phase arrest (p < 0.01) compared to either CENP-N knockdown alone or radiotherapy alone. The combined treatment group showed the highest increase in Bax and γH2AX protein levels, whereas the protein Cyclin D1 exhibited the greatest decrease (p < 0.01). However, the above changes were reversed after treatment with AKT activator SC79. In vivo, the mean volume and weight of tumors in the radiotherapy group were 182 ± 54 mm3 and 0.16 ± 0.03 g. The mean tumor volume and weight in the combined treatment group were 84 ± 42 mm3 and 0.04 ± 0.01 g.

CONCLUSION

Knockdown of CENP-N can enhance NPC radiosensitivity by inhibiting AKT/mTOR.

Construction and validation of a prognostic nine-gene signature associated with radiosensitivity in head and neck squamous cell carcinoma

Background

Radiotherapy is an effective treatment for head and neck squamous cell carcinoma (HNSCC), however how to predict the prognosis is not clear.

Methods

Here we collected 262 radiosensitivity-associated genes, screened and constructed a prognostic nine-gene risk model through univariate COX, lasso regression, stepwise regression and multivariate COX analysis for transcriptome and clinical information of HNSCC patients obtained from the cancer genome atlas (TCGA) and gene expression omnibus (GEO) databases.

Results

The reliability and robustness of the risk model were verified by receiver operating characteristic (ROC) curves, risk maps, and Kaplan-Meier (KM) curves analysis. Differences in immune cell infiltration and immune-related pathway enrichment between high-risk and low-risk subgroups were determined by multiple immune infiltration analyses. Meanwhile, the mutation map and the responses to immunotherapy were also differentiated by the prognostic nine-gene signature associated with radiosensitivity. These nine genes expression in HNSCC was verified in the Human Protein Atlas (HPA) database. After that, these nine genes expression was verified to be related to radiation resistance through in-vitro cell experiments.

Conclusions

All results showed that the nine-gene signature associated with radiosensitivity is a potential prognostic indicator for HNSCC patients after radiotherapy and provides potential gene targets for enhancing the efficacy of radiotherapy.

Radiation-sensitive genetic prognostic model identifies individuals at risk for radiation resistance in head and neck squamous cell carcinoma

BACKGROUND

The advantages of radiotherapy for head and neck squamous cell carcinoma (HNSCC) depend on the radiation sensitivity of the patient. Here, we established and verified radiological factor-related gene signature and built a prognostic risk model to predict whether radiotherapy would be beneficial.

METHODS

Data from The Cancer Genome Atlas, Gene Expression Omnibus, and RadAtlas databases were subjected to LASSO regression, univariate COX regression, and multivariate COX regression analyses to integrate genomic and clinical information from patients with HNSCC. HNSCC radiation-related prognostic genes were identified, and patients classified into high- and low-risk groups, based on risk scores. Variations in radiation sensitivity according to immunological microenvironment, functional pathways, and immunotherapy response were investigated. Finally, the expression of HNSCC radiation-related genes was verified by qRT-PCR.

RESULTS

We built a clinical risk prediction model comprising a 15-gene signature and used it to divide patients into two groups based on their susceptibility to radiation: radiation-sensitive and radiation-resistant. Overall survival was significantly greater in the radiation-sensitive than the radiation-resistant group. Further, our model was an independent predictor of radiotherapy response, outperforming other clinical parameters, and could be combined with tumor mutational burden, to identify the target population with good predictive value for prognosis at 1, 2, and 3 years. Additionally, the radiation-resistant group was more vulnerable to low levels of immune infiltration, which are significantly associated with DNA damage repair, hypoxia, and cell cycle regulation. Tumor Immune Dysfunction and Exclusion scores also suggested that the resistant group would respond less favorably to immunotherapy.

CONCLUSIONS

Our prognostic model based on a radiation-related gene signature has potential for application as a tool for risk stratification of radiation therapy for patients with HNSCC, helping to identify candidates for radiation therapy and overcome radiation resistance.

Valproic acid radiosensitizes anaplastic thyroid cells through a decrease of the DNA damage repair capacity

BACKGROUND

Anaplastic thyroid cancer (ATC) represents a rare lethal human malignancy with poor prognosis. Multimodality treatment, including radiotherapy, is recommended to improve local control and survival. Valproic acid (VA) is a clinically available histone deacetylase inhibitor with a well-documented side effect profile. In this study, we aim to investigate the combined effect of VA with photon irradiation in vitro.

METHODS

Anaplastic thyroid cancer cells (8505c) were used to investigate the radiosensitizing effect of VA.

RESULTS

VA sensitized cells to photon irradiation. VA increased radiation-induced apoptosis and radiation-induced DNA damage measured by γH2AX foci induction. Furthermore, VA prolonged γH2AX foci disappearance over time in irradiated cells and decreased the radiation-induced levels of mRNA of key DNA damage repair proteins of the homologous recombination (HR) and the nonhomologous end joining (NHEJ) pathways.

CONCLUSIONS

VA at a clinically safe dose enhance the radiosensitivity of 8505c cells through an increase in radiation-induced apoptosis and a disruption in the molecular mechanism of HR and NHEJ DNA damage repair pathways.

Curcumol β-cyclodextrin inclusion complex enhances radiosensitivity of esophageal cancer under hypoxic and normoxic condition

PURPOSE

Radiotherapy is an indispensable treatment for esophageal cancer (EC), but radioresistance is not uncommon. Curcumol, as an active extract from traditional Chinese medicines, has been reported to have antitumor activity in various types of human tumor cells. However, its reversal of radioresistance has been rarely reported.

MATERIALS AND METHODS

In the present study, curcumol was prepared as an inclusion complex with β-cyclodextrin. EC cell lines were treated with radiation and curcumol β-cyclodextrin inclusion complex (CβC), and the effect of radiosensitization of CβC was investigated in vitro and in vivo. The in vitro experiments included cell proliferation assay, clonogenic survival assay, apoptosis assay, cell cycle assay, and western blot assay.

RESULTS

The in vitro data revealed that CβC and irradiation synergistically inhibited the proliferation, reduced the colony formation, promoted the apoptosis, increased the G2/M phase, inhibited DNA damage repair, and reversed the hypoxia-mediated radioresistance of EC cells to a greater extent than did CβC alone or irradiation alone. The sensitization enhancement ratios (SERs) were 1.39 for TE-1 and 1.48 for ECA109 under hypoxia. The SERs were 1.25 for TE-1 and 1.32 for ECA109 under normoxia. The in vivo data demonstrated that the combination of CβC and irradiation could inhibit tumor growth to the greatest extent compared with either monotherapy alone. The enhancement factor was 2.45.

CONCLUSION

This study demonstrated that CβC could enhance radiosensitivity of EC cells under hypoxic and normoxic condition. Thus, CβC can be used as an effective radiosensitizer for EC.

Predictive capacity of FAT1 transcriptional expression in patients with head and neck squamous cell carcinomas treated with radiotherapy

OBJECTIVE

To analyze the predictive capacity at the primary location of the tumor of the FAT1 transcriptional expression in patients with head and neck squamous cell carcinoma treated with radiotherapy.

MATERIAL AND METHODS

We conducted a retrospective study from biopsies of the primary location of the tumor in 82 patients with head and neck squamous cell carcinoma treated with radiotherapy. The transcriptional expression of FAT1 was determined by RT-PCR. The level of FAT1 transcriptional expression was categorized according to the local control after radiotherapy using a recursive partitioning analysis.

RESULTS

Elevated FAT1 transcriptional expression was associated with an increased risk of local recurrence after radiotherapy. Patients with a high expression level of FAT1 (n=18; 22.0%) had a 5-year local recurrence-free survival of 42.1% (95% CI: 18.6%-65.6%), whereas for patients with a low expression (n=64; 78.0%) it was 72.4% (95% CI: 61.5%-83.3%) (p=0.002). According to the result of a multivariate analysis, patients with a high FAT1 expression category had a 2.3-fold increased risk of local recurrence (95% CI: 1.0-5.2; p=0.043).

CONCLUSIONS

Elevated FAT1 transcriptional expression was associated with a significantly increased risk of local recurrence in patients with head and neck squamous cell carcinoma treated with radiotherapy.

[Hsa_circ_0000392 affects the radiation sensitivity of cervical cancer by targeting the miR-145-5p/CRKL/MAPK pathway]

Objective: To investigate the effect of hsa_circ_0000392 (circ_0000392) on the radiosensitivity of cervical cancer cells and explore its potential mechanism. Methods: Cervical cancer tissues and adjacent normal tissues of 42 patients with cervical cancer who were confirmed pathologically for the first time in Huaihe Hospital of Henan University from 2016 to 2019 were collected. According to the patients' response to radiotherapy, the cancer tissues were divided into radio-sensitive tissues and radio-resistant tissues. The expressions of circ_0000392, miR-145-5p, and CRKL in radiation-sensitive, radiation-resistant cervical cancer tissues and Hela, SiHa cells were detected by reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR) and western blot. SiRNA circ_0000392, miR-145-5p mimic, miR-145-5p inhibitor, pcDNA 3.1-CRKL and its negative control were transfected into HeLa and Siha cells, respectively. After radiation induction, the survival fraction of cells was detected by clone formation assay, apoptosis was detected by flow cytometry, and the expressions of apoptosis-related proteins Bax and Bcl-2 and ERK pathway protein p-ERK1/2 and ERK1/2 were detected by western blot. The targeting relationship between circ_0000392, miR-145-5p and CRKL was verified by dual luciferase reporter gene assay. The effect of circ_0000392 on radiotherapy sensitivity of cervical cancer in vivo was observed in the tumor formation experiment in nude mice. Results: circ_0000392 and CRKL were upregulated in radiation-resistant tissues and cancer cells of cervical cancer, while miR-145-5p was downregulated. The clone formation numbers of Hela and SiHa cells in si-circ_0000392#1+ 6 Gy group were (78.67±10.97) and (71.00±9.54), respectively, which were lower than those in si-Ctrl+ 6 Gy group [(176.00±22.27) and (158.33±17.56), respectively]. The apoptosis rates were (41.55±3.40)% and (31.41±3.29)%, respectively, which were higher than those in si-Ctrl+ 6 Gy group [(15.91±1.37)% and (13.70±1.89)%, P<0.05]. The protein expression of Bax was higher than that of si-Ctrl+ 6 Gy group, and the protein expressions of Bcl2 was lower than those of si-Ctrl+ 6 Gy group. The clone formation numbers of Hela and SiHa cells in si-circ_0000392#1+ miR-145-5p inhibitor+ 6 Gy group were (171.33±25.01) and (137.00±21.66), higher than those in si-circ_0000392#1+ inhibitor NC+ 6 Gy group [(84.67±17.79) vs (71.00±11.00), P<0.05]. The apoptosis rates were (17.41±2.58) % and (15.96±1.25) %, lower than those of si-circ_0000392 #1+ inhibitor NC+ 6 Gy [(40.29±2.92)% and (30.82±2.34)%, respectively, P<0.05]. The expression of Bax protein was lower than that of si-circ_0000392#1+ inhibitor NC+ 6 Gy group, and the expressions of Bcl2 protein were higher than those of si-circ_0000392#1+ inhibitor NC+ 6 Gy group. Circ_0000392 can target miR-145-5p, and CRKL is the downstream target gene of miR-145-5p. The clone formation numbers of Hela and SiHa cells in miR-145-5p mimic+ 6 Gy group were (74.33±10.02) and (66.00±12.17), respectively, which were lower than those of mimic NC+ 6 Gy group [(197.67±17.21) vs (157.67±11.59), respectively, P<0.05]. The apoptosis rates were (45.58±2.16)% and (32.10±3.55)%, higher than those of mimic NC+ 6 Gy group [(15.85±2.45)% and (13.99±1.69)%, respectively, P<0.05]. The expression of Bax protein was higher than that of the mimic NC+ 6 Gy mimic group, and the expression of Bcl2 protein was lower than that of the mimic NC+ 6 Gy group. The clone formation numbers of Hela and SiHa cells in miR-145-5p mimic+ pcDNA-CRKL+ 6 Gy group were (158.00±15.88) and (122.33±13.65), respectively, which were higher than those of miR-145-5p mimic+ pcDNA+ 6 Gy group [(71.33±8.02) vs (65.67±12.22), P<0.05]. The apoptosis rates were (19.50±3.45)% and (17.04±0.94)%, respectively, which were lower than those of miR-145-5p mimic+ pcDNA+ 6 Gy group [(44.33±2.36)% and (32.05±2.76)%, respectively, P<0.05]. The expression of Bax protein was lower than that of miR-145-5p mimic+ pcDNA group+ 6 Gy group, and the expression of Bcl2 protein was higher than that of miR-145-5p mimic+ pcDNA+ 6 Gy group. Sh-circ_0000392 group had smaller tumor volume and decreased tumor weight (P<0.05). The relative mRNA expression levels of circ_0000392, miR-145-5p and CRKL and the relative protein expression levels of CRKL, Bcl-2 and p-ERK1/2 were decreased, while the relative expression level of Bax protein was increased (P<0.05). Conclusion: Circ_0000392 could enhance the radiosensitivity of cervical cancer cells, and its mechanism may be related to the regulation of CRKL/ERK signaling pathway by targeting miR-145-5p, which provides a new reference for enhancing the radiosensitivity of cervical cancer cells.

Role of Radiation in Treatment of Renal Cell Carcinoma

Initial studies of radiotherapy in renal cell carcinoma (RCC) failed to demonstrate significant clinical impact. With the advent of stereotactic body radiotherapy (SBRT) that allows for delivery of more effective radiation doses in a precise fashion, radiotherapy has become an essential component in the multidisciplinary management of patients with RCC both in the setting of localized and metastatic disease beyond the traditional role of palliative treatment. Recent evidence has demonstrated high rates of long-term local control (∼95%) when SBRT is delivered to kidney tumors with limited toxicity risks and only minor impact on renal function.

APE1 promotes radiation resistance against radiation-induced pyroptosis by inhibiting the STING pathway in lung adenocarcinoma

Mammalian apurinic/apyrimidinic endonuclease 1 (APE1, APEX1) is a multifunctional enzyme that maintains cellular homeostasis. It is involved in the base excision repair (BER) pathway and plays a key role in radiation-induced DNA damage response. However, the relationship between APE1-driven radiation resistance and pyroptosis in lung adenocarcinoma (LUAD) cells and the underlying molecular mechanisms remain unclear. We found that APE1 was significantly upregulated in LUAD tissues compared to para-carcinoma tissues and promoted the proliferation and invasion of LUAD cells in vitro and in vivo. Mechanistically, APE1 inhibited pyroptosis by inactivating the interferon gene stimulator (STING) pathway via direct interaction with AIM2 and DDX41, as detected by RNA-seq and co-immunoprecipitation. APE1 protects LUAD cells against radiation-induced damage and induces radio-resistance by targeting the STING pathway. It can induce pyroptosis and is negatively regulated by interactions with AIM2 and DDX41. Therefore, APE1 inhibitors should be considered to enhance the radiosensitivity of LUAD cells and improve patient prognosis and therapeutic outcomes. Thus, APE1 play a role in the tumor immune microenvironment and in tumor immunotherapy.

SHF confers radioresistance in colorectal cancer by the regulation of mitochondrial DNA copy number

Altered mitochondrial function contributes greatly to pathogenesis and progression of colorectal cancer. In this study, we report a functional pool of Src homology 2 domain-containing F (SHF) in mitochondria controlling the response of colorectal cancer cells to radiation therapy. We found that elevated expression of SHF in cancer cells is essential for promoting mitochondrial function by increasing mitochondrial DNA copy number, thus reducing the sensitivity of colorectal cancer cells to radiation. Mechanistically, SHF binds to mitochondrial DNA and promotes POLG/SSBP1-mediated mitochondrial DNA synthesis. Importantly, SHF loss-mediated radiosensitization was phenocopied by depletion of mitochondrial DNA. Thus, our data demonstrate that mitochondrial SHF is an important regulator of radioresistance in colorectal cancer cells, identifying SHF as a promising therapeutic target to enhance radiotherapy efficacy in colorectal cancer.

POT1 involved in telomeric DNA damage repair and genomic stability of cervical cancer cells in response to radiation

Though telomeres play a crucial role in maintaining genomic stability in cancer cells and have emerged as attractive therapeutic targets in anticancer therapy, the relationship between telomere dysfunction and genomic instability induced by irradiation is still unclear. In this study, we identified that protection of telomeres 1 (POT1), a single-stranded DNA (ssDNA)-binding protein, was upregulated in γ-irradiated HeLa cells and in cancer patients who exhibit radiation tolerance. Knockdown of POT1 delayed the repair of radiation-induced telomeric DNA damage which was associated with enhanced H3K9 trimethylation and enhanced the radiosensitivity of HeLa cells. The depletion of POT1 also resulted in significant genomic instability, by showing a significant increase in end-to-end chromosomal fusions, and the formation of anaphase bridges and micronuclei. Furthermore, knockdown of POT1 disturbed telomerase recruitment to telomere, and POT1 could interact with phosphorylated ATM (p-ATM) and POT1 depletion decreased the levels of p-ATM induced by irradiation, suggesting that POT1 could regulate the telomerase recruitment to telomeres to repair irradiation-induced telomeric DNA damage of HeLa cells through interactions with p-ATM. The enhancement of radiosensitivity in cancer cells can be achieved through the combination of POT1 and telomerase inhibitors, presenting a potential approach for radiotherapy in cancer treatment.

Dual enhancement in the radiosensitivity of prostate cancer through nanoparticles and chemotherapeutics

Background

Radiotherapy (RT) is an essential component in the treatment regimens for many cancer patients. However, the dose escalation required to improve curative results is hindered due to the normal tissue toxicity that is induced. The introduction of radiosensitizers to RT treatment is an avenue that is currently being explored to overcome this issue. By introducing radiosensitizers into tumor sites, it is possible to preferentially enhance the local dose deposited. Gold nanoparticles (GNPs) are a potential candidate that have shown great promise in increasing the radiosensitivity of cancer cells through an enhancement in DNA damage. Furthermore, docetaxel (DTX) is a chemotherapeutic agent that arrests cells in the G2/M phase of the cell cycle, the phase most sensitive to radiation damage. We hypothesized that by incorporating DTX to GNP-enhanced radiotherapy treatment, we could further improve the radiosensitization experienced by cancer cells. To assess this strategy, we analyzed the radiotherapeutic effects on monolayer cell cultures in vitro, as well as on a mice prostate xenograft model in vivo while using clinically feasible concentrations for both GNPs and DTX.

Results

The introduction of DTX to GNP-enhanced radiotherapy further increased the radiotherapeutic effects experienced by cancer cells. A 38% increase in DNA double-strand breaks was observed with the combination of GNP/DTX vs GNP alone after a dose of 2 Gy was administered. In vivo results displayed significant reduction in tumor growth over a 30-day observation period with the treatment of GNP/DTX/RT when compared to GNP/RT after a single 5 Gy dose was given to mice. The treatment strategy also resulted in 100% mice survival, which was not observed for other treatment conditions.

Conclusions

Incorporating DTX to work in unison with GNPs and RT can increase the efficacy of RT treatment. Our study suggests that the treatment strategy could improve tumor control through local dose enhancement. As the concentrations used in this study are clinically feasible, there is potential for this strategy to be translated into clinical settings.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12645-023-00228-0.

miR-4796 enhances the sensitivity of breast cancer cells to ionising radiation by impairing the DNA repair pathway

BACKGROUND

MicroRNAs (miRNAs) are important regulators of DNA damage response (DDR) through post-transcriptional regulation on their target genes, which are implicated in DDR and DNA repair (DR). In this study, we investigated the functional roles and target genes of miR-4796 and miR-1287 in breast cancer cells in response to radiation. The molecular mechanism of miR-4796 in regulating the radiosensitivity of breast cancer cells was also elucidated.

METHODS

Real-time polymerase chain reaction detected miR-4796 and miR-1287 expression; colony formation assay and irradiation therapy tumour xenograft in vivo examined radiosensitising effect; comet assay assessed DNA damage; immunofluorescence imaging determined the formation of γ-H2AX foci; targetscan and RegRNA predicted target mRNAs; luciferase reporter and mutation assays validated target genes; western blotting detected the expression of genes at the protein level; and flow cytometry quantified the activities of nonhomologous end-joining (NHEJ) and homologous recombination (HR).

RESULTS

The expressions of miR-4796 and miR-1287 were acutely fluctuated in response to ionising radiation. In the absence of radiation, overexpression of miR-1287 dramatically promoted growth of breast cancer cells in vitro and in vivo, whereas overexpression of miR-4796 did not affect cell growth. When under the treatment with radiation, overexpression of miR-4796 suppressed DR and sensitised cancer cells to radiation both in vitro and in vivo. However, such effect was only observed in cell assays in the overexpressed miR-1287 group, and not confirmed in vivo. We therefore further explored the molecular mechanism of action of miR-4796, and found that miR-4796 targeted multiple components of DDR and DR, including ATM, BRCA1, PARP and RAD51. Moreover, overexpression of miR-4796 inhibited the expression of these DDR components at the protein level. In addition, miR-4796 inhibited HR and NHEJ repair pathways and aggravated radiation-induced DNA damage.

CONCLUSIONS

The findings here suggest that miR-4796 can enhance radiation-induced cell death by directly targeting multiple DDR components, and repress NHEJ and HR DNA repair pathways. miR-4796 can act as an effective radiation sensitising agent.

TBX18 knockdown sensitizes esophageal squamous cell carcinoma to radiotherapy by blocking the CHN1/RhoA axis

OBJECTIVE

Radioresistance is a challenge in the effective treatment of esophageal squamous cell carcinoma (ESCC). Herein, this research ascertained whether TBX18 reduced the radiosensitivity of ESCC.

METHODS

Bioinformatics analysis was utilized to retrieve differentially expressed genes. Then, the expression of corresponding candidate genes was tested using qRT-PCR in ESCC clinical specimens, and TBX18 was selected for subsequent experiments. The binding between TBX18 and CHN1 was evaluated by dual-luciferase reporter and ChIP assays, and the relationship between CHN1 and RhoA was identified by GST pull-down. Ectopic expression or knockdown experiments and radiation treatment were performed in cells and the nude mouse xenograft model to clarify the impacts of TBX18, CHN1, and RhoA on radiosensitivity in ESCC.

RESULTS

Bioinformatics analysis and qRT-PCR retrieved upregulated TBX18 in ESCC for the follow-up study. Additionally, TBX18 was positively correlated with CHN1 in ESCC clinical specimens. Mechanistically, TBX18 bound to the CHN1 promoter region to transcriptionally activate CHN1, thus elevating RhoA activity. Moreover, TBX18 knockdown reduced ESCC cell proliferation and migration while augmenting their apoptosis after radiation, which was negated by further overexpressing CHN1 or RhoA. CHN1 or RhoA knockdown diminished ESCC cell proliferation and migration, as well as enhanced cell apoptosis, subsequent to radiation. Likewise, TBX18 overexpression increased ESCC cell autophagy after radiation, which was partially reversed by knockdown of RhoA. The results of in vivo xenograft experiments in nude mice were concurrent with the in vitro results.

CONCLUSION

TBX18 knockdown lowered CHN1 transcription and thus reduced RhoA activity, which sensitized ESCC cells to radiotherapy.

[The morbidity and mortality review meetings in radiotherapy departments: Procedure, implementation and prospects of the "Proust" French national project]

Radiation-induced acute and late toxicity depends on several parameters. The type, severity and duration of morbidity are mainly related to irradiated volume, total dose and its fractionation and the intrinsic radiosensitivity of the patients. The follow-up of these toxicities is essential. However, unlike many specialties, morbidity and mortality reviews procedures are not developed as part of quality governance programs in radiation therapy departments for the monitoring of toxicity which sometimes hinder the patients' quality of life. One French survey published within the framework of the project entitled Prospective Registration of Morbidity and Mortality, Individual Radiosensitivity and Radiation Technique (Proust), conclude that there was a lack of knowledge of morbidity and mortality reviews and considerable confusion between these reviews and other quality processes without perspective for the local morbidity and mortality reviews development in a large number of the participated centers. In this article, we will discuss the procedure of the "ideal morbidity and mortality reviews" and its implementation through a monocentric experience started in 2015. Thus, the Proust project is a unique opportunity to implement and standardize a national morbidity and mortality reviews implementation in radiation therapy departments by involving the French regions.

Dysregulated Stem Cell Markers Musashi-1 and Musashi-2 are Associated with Therapy Resistance in Inflammatory Breast Cancer

BACKGROUND AND AIM

While preliminary evidence points to pro-tumorigenic roles for the Musashi (MSI) RNA-binding proteins Musashi-1 (MSI1) and Musashi-2 (MSI2) in some breast cancer subtypes, no data exist for inflammatory breast cancer (IBC).

METHODS

MSI gene expression was quantified in IBC SUM149PT cells. We then used small interfering RNA-based MSI1 and MSI2 double knockdown (DKD) to understand gene expression and functional changes upon MSI depletion. We characterized cancer stem cell characteristics, cell apoptosis and cell cycle progression via flow cytometry, mammospheres via spheroid assays, migration and proliferation via digital holographic microscopy, and cell viability using BrdU assays. Chemoresistance was determined for paclitaxel and cisplatin with MTT assays and radioresistance was assessed with clonogenic analyses. In parallel, we supported our in vitro data by analyzing publicly available patient IBC gene expression datasets.

RESULTS

MSI1 and MSI2 are upregulated in breast cancer generally and IBC specifically. MSI2 is more commonly expressed compared to MSI1. MSI DKD attenuated proliferation, cell cycle progression, migration, and cell viability while increasing apoptosis. Stem cell characteristics CD44(+)/CD24(-), TERT and Oct4 were associated with MSI expression in vivo and were decreased in vitro after MSI DKD as was ALDH expression and mammosphere formation. In vivo, chemoresistant tumors were characterized by MSI upregulation upon chemotherapy application. In vitro, MSI DKD was able to alleviate chemo- and radioresistance.

CONCLUSIONS

The Musashi RNA binding proteins are dysregulated in IBC and associated with tumor proliferation, cancer stem cell phenotype, chemo- and radioresistance. MSI downregulation alleviates therapy resistance and attenuates tumor proliferation in vitro.

The relation between hypoxia and proliferation biomarkers with radiosensitivity in locally advanced laryngeal cancer

PURPOSE

Treatment decision-making in advanced-stage laryngeal squamous cell carcinoma (LSCC) is difficult due to the high recurrence rates and the desire to preserve laryngeal functions. New predictive markers for radiosensitivity are needed to facilitate treatment choices. In early stage glottic LSCC treated with primary radiotherapy, expression of hypoxia (HIF-1α and CA-IX) and proliferation (Ki-67) tumour markers showed prognostic value for local control. The objective of this study is to examine the prognostic value of tumour markers for hypoxia and proliferation on locoregional recurrent disease and disease-specific mortality in a well-defined cohort of patients with locally advanced LSCC treated with primary, curatively intended radiotherapy.

METHODS

In pre-treatment biopsy tissues from a homogeneous cohort of 61 patients with advanced stage (T3-T4, M0) LSCC primarily treated with radiotherapy, expression of HIF-1α, CA-IX and Ki-67 was evaluated with immunohistochemistry. Demographic data (age and sex) and clinical data (T- and N-status) were retrospectively collected from the medical records. Cox regression analysis was performed to assess the relation between marker expression, demographic and clinical data, and locoregional recurrence and disease-specific mortality.

RESULTS

Patients with high expression of HIF-1α developed significantly more often a locoregional recurrence (39%) compared to patients with a low expression (21%) (p = 0.002). The expression of CA-IX and Ki-67 showed no association with locoregional recurrent disease. HIF-1α, CA-IX and Ki-67 were not significantly related to disease-specific mortality. Clinical N-status was an independent predictor of recurrent disease (p < 0.001) and disease-specific mortality (p = 0.003). Age, sex and T-status were not related to locoregional recurrent disease or disease-specific mortality.

CONCLUSION

HIF-1α overexpression and the presence of regional lymph node metastases at diagnosis were independent predictors of locoregional recurrent disease after primary treatment with curatively intended radiotherapy in patients with locally advanced LSCC.

Epigenetic regulation of circ-HIPK3, circ-PVT1, miR-25, and miR-149 in radiosensitivity of breast cancer

Assessing the radiosensitivity of cells before administering radiation therapy (RT) to individuals diagnosed with breast cancer (BC) can facilitate the selection of appropriate treatment regimens and minimize the incidence of adverse side effects in patients undergoing radiation exposure. In this research, blood samples were obtained from 60 women who had been diagnosed with Invasive Ductal Carcinoma (IDC) Breast Cancer. The average age of the patients was 47 ± 9.93. Additionally, the study incorporated 20 healthy women, with an average age of 44.43 ± 6.7. A standard G2 assay was conducted to predict the cellular response to radiation. Out of the 60 samples, the G2 assay identified 20 patients with breast cancer who exhibited radiosensitivity. Hence, molecular investigations were ultimately conducted on two equivalent cohorts comprising 20 subjects each, one with and the other without cellular radiosensitivity. The expression levels of miR-149, miR-25, circ-PVT1, and circ-HIPK3 in peripheral blood mononuclear cells (PBMCs) were evaluated using quantitative polymerase chain reaction (qPCR). Receiver Operating Characteristic (ROC) curves were used to evaluate the sensitivity and specificity of the RNAs. An analysis using binary logistic regression was performed to investigate the relationship between RNAs and both BC and cellular radiosensitivity (CR) in patients with BC. The findings revealed a significant upregulation of Circ-HIPK3 and circ-PVT1 in individuals diagnosed with BC. The levels of Circ-HIPK3 and Circ-PVT1 were found to be directly associated with CR in BC patients. The analysis of the ROC curve demonstrated that circ-HIPK3 and circ-PVT1 exhibit favorable specificity and sensitivity in accurately predicting both BC and CR in patients with BC. The findings from the binary logistic regression analysis demonstrated that circ-HIPK3 and circ-PVT1 were effective predictors of both BC and CR. The ROC curve and binary logistic regression analyses provide evidence that miR-25 is a reliable predictor for BC patients exclusively. Our research has demonstrated that circ-HIPK3, circ-PVT1, and miR-25 may be involved in BC regulatory processes. The circular RNAs Circ-HIPK3 and circ-PVT1, as well as miR-25, among other significant biomarkers, could potentially serve as promising biomarkers for predicting BC. Furthermore, Circ-HIPK3 and circ-PVT1 have the potential to serve as biomarkers for predicting CR in BC patients.

Mitochondrial metabolism: a predictive biomarker of radiotherapy efficacy and toxicity

INTRODUCTION

Radiotherapy is a mainstay of cancer treatment. Clinical studies revealed a heterogenous response to radiotherapy, from a complete response to even disease progression. To that end, finding the relative prognostic factors of disease outcomes and predictive factors of treatment efficacy and toxicity is essential. It has been demonstrated that radiation response depends on DNA damage response, cell cycle phase, oxygen concentration, and growth rate. Emerging evidence suggests that altered mitochondrial metabolism is associated with radioresistance.

METHODS

This article provides a comprehensive evaluation of the role of mitochondria in radiotherapy efficacy and toxicity. In addition, it demonstrates how mitochondria might be involved in the famous 6Rs of radiobiology.

RESULTS

In terms of this idea, decreasing the mitochondrial metabolism of cancer cells may increase radiation response, and enhancing the mitochondrial metabolism of normal cells may reduce radiation toxicity. Enhancing the normal cells (including immune cells) mitochondrial metabolism can potentially improve the tumor response by enhancing immune reactivation. Future studies are invited to examine the impacts of mitochondrial metabolism on radiation efficacy and toxicity. Improving radiotherapy response with diminishing cancer cells' mitochondrial metabolism, and reducing radiotherapy toxicity with enhancing normal cells' mitochondrial metabolism.

ADNP is associated with immune infiltration and radiosensitivity in hepatocellular carcinoma for predicting the prognosis

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most lethal diseases due to its high faculty of invasiveness and metastasis. Activity-dependent neuroprotective protein (ADNP) has been regarded as an oncogene in bladder cancer and ovarian cancer. However, the role of ADNP in the regulation of tumor immune response, development, and treatment resistance in HCC remains unknown and is worth exploring.

METHODS

The correlation between ADNP and prognosis, immune cell infiltration, immune checkpoints, chemokines, tumor mutation burden, microsatellite instability, and genomic mutation of pan-cancer cohorts in The Cancer Genome Atlas was analyzed. ADNP expression in HCC cell lines, HCC and the adjacent normal tissues was measured by western blotting and immunochemistry. Nomogram was constructed to predict the survival of patients with HCC based on the ADNP expression and significant clinical characteristics. The potential biological functions and impacts on radiotherapy of ADNP in HCC cell lines were verified by vitro experiments.

RESULTS

ADNP was upregulated in most cancers and patients with elevated ADNP expression were related to poor survival in several types of cancers including HCC. Functional enrichment analysis showed ADNP participated in the pathways correlated with coagulation cascades and DNA double strand break repair. Further, ADNP exhibited a negative correlation with the immune score, stromal score, estimated score, and chemokines, and a positive correlation with cancer-associated fibroblasts, myeloid-derived suppressor cells, neutrophils, regulatory T cells, and endothelial cells. Immunochemistry and western blotting results demonstrated ADNP was up-regulated in HCC. Vitro experiments verified that suppressing the ADNP expression significantly inhibited the proliferation, invasion and migration and elevated the radiosensitivity via decreasing DNA damage repair in HCC.

CONCLUSION

ADNP might play an oncogene and immunosuppression role in tumor immune infiltration and response, thus influencing the prognosis. Its downregulation could attenuate the proliferation, invasion, migration, radioresistance of HCC. Our results indicated the potential of ADNP as a promising biomarker to predict the survival of HCC patients, providing a theoretical basis for novel integrative strategies.

CircNCOR1 regulates breast cancer radiotherapy efficacy by regulating CDK2 via hsa-miR-638 binding

BACKGROUND

Despite aggressive local and regional therapy, triple-negative breast cancer (TNBC) is characterized by an increased risk of locoregional recurrence. RNA-sequencing data has identified a large number of circRNAs in primary breast cancers, but the role of specific circRNAs in regulating the radiosensitivity of TNBC is not fully understood. This research aimed to investigate the function of circNCOR1 in the radiosensitivity of TNBC.

METHODS

CircRNA high-throughput sequencing was conducted on two breast cancer MDA-MB-231 and BT549 cell lines after 6 Gy radiation. The relationship between circNCOR1, hsa-miR-638, and CDK2 was determined by RNA immunoprecipitation (RIP), FISH and luciferase assays. The proliferation and apoptosis of breast cancer cells were measured by CCK8, flow cytometry, colony formation assays, and western blot.

RESULTS

Differential expression of circRNAs was closely related to the proliferation of breast cancer cells after irradiation. Overexpression of circNCOR1 facilitated the proliferation of MDA-MB-231 and BT549 cells and impaired the radiosensitivity of breast cancer cells. Additionally, circNCOR1 acted as a sponge for hsa-miR-638 to regulate the downstream target protein CDK2. Overexpression of hsa-miR-638 promoted apoptosis of breast cancer cells, while overexpression of CDK2 alleviated apoptosis and increased proliferation and clonogenicity. In vivo, overexpression of circNCOR1 partially reversed radiation-induced loosening of tumor structures and enhanced tumor cell proliferation.

CONCLUSION

Our results demonstrated that circNCOR1 bounds to hsa-miR-638 and targets CDK2, thereby regulating the radiosensitivity of TNBC.

Chromosomal radiosensitivity in oncological and non-oncological patients with rheumatoid arthritis and connective tissue diseases

BACKGROUND

The risk of developing late radiotoxicity after radiotherapy in patients with high chromosomal radiosensitivity after radiotherapy could potentially be higher compared to the risk in patients with average radiosensitivity. In case of extremely high radiosensitivity, dose reduction may be appropriate. Some rheumatic diseases (RhD), including connective tissue diseases (CTDs) appear to be associated with higher radiosensitivity. The question arises as to whether patients with rheumatoid arthritis (RA) also generally have a higher radiosensitivity and whether certain parameters could indicate clues to high radiosensitivity in RA patients which would then need to be further assessed before radiotherapy.

METHODS

Radiosensitivity was determined in 136 oncological patients with RhD, 44 of whom were RA patients, and additionally in 34 non-oncological RA patients by three-colour fluorescence in situ hybridization (FiSH), in which lymphocyte chromosomes isolated from peripheral blood are analysed for their chromosomal aberrations of an unirradiated and an with 2 Gy irradiated blood sample. The chromosomal radiosensitivity was determined by the average number of breaks per metaphase. In addition, correlations between certain RA- or RhD-relevant disease parameters or clinical features such as the disease activity score 28 and radiosensitivity were assessed.

RESULTS

Some oncological patients with RhD, especially those with connective tissue diseases have significantly higher radiosensitivity compared with oncology patients without RhD. In contrast, the mean radiosensitivity of the oncological patients with RA and other RhD and the non-oncological RA did not differ. 14 of the 44 examined oncological RA-patients (31.8%) had a high radiosensitivity which is defined as ≥ 0.5 breaks per metaphase. No correlation of laboratory parameters with radiosensitivity could be established.

CONCLUSIONS

It would be recommended to perform radiosensitivity testing in patients with connective tissue diseases in general. We did not find a higher radiosensitivity in RA patients. In the group of RA patients with an oncological disease, a higher percentage of patients showed higher radiosensitivity, although the average radiosensitivity was not high.

Radiosensitivity and early onset cancer

The article is concerned with the radioprotection of a substantial radiosensitive population who present with cancer in early adulthood and will probably be treated with radiotherapy. A theory of radiation-induced health effects based on the induction of DNA double strand breaks is used to associate the radio-sensitivity of carriers of the BRCA1 and BRCA2 genes and the PALB2 gene with the defects in the homologous recombination repair of DNA damage found in the carriers. It is concluded that the defects in homologous recombination repair in these carriers will lead to an increased level of somatic mutations in all their cells and that this increased level of somatic mutations throughout their lifetime is, essentially, the reason that the carriers develop early onset cancer. This is a direct consequence of the more rapid accumulation of the cancer-inducing somatic mutations than the normal, slower accumulation in non-carriers. The radiotherapeutic treatment of these carriers needs to proceed with some care, taking account of their increased radio-sensitivity, and this suggests a need for international recognition and guidance of their radioprotection within the medical profession.&#xD.