Corrigendum: ITGB5 promotes innate radiation resistance in pancreatic adenocarcinoma by promoting DNA damage repair and the MEK/ERK signaling pathway

[This corrects the article DOI: 10.3389/fonc.2022.887068.].

LncRNA FAM83H-AS1 Contributes to the Radio-resistance and Proliferation in Liver Cancer through Stability FAM83H Protein

BACKGROUND

Liver cancer (LC) is one of China's most common malignant tumors, with a high mortality rate, ranking third leading cause of death after gastric and esophageal cancer. Recent patents propose the LncRNA FAM83H-AS1 has been verified to perform a crucial role in the progression of LC. LncRNA FAM83H-AS1 has been verified to perform a crucial role in the progression of LC. However, the concrete mechanism remains to be pending further investigation.

OBJECTIVE

This study aimed to explore the embedding mechanism of FAM83H-AS1 molecules in terms of radio sensitivity of LC and provide potentially effective therapeutic targets for LC therapy.

METHODS

Quantitative real-time PCR (qRT-PCR) was conducted to measure the transcription levels of genes. Proliferation was determined via CCK8 and colony formation assays. Western blot was carried out to detect the relative protein expression. A xenograft mouse model was constructed to investigate the effect of LncRNA FAM83H-AS1 on tumor growth and radio-sensitivity in vivo.

RESULTS

The levels of lncRNA FAM83H-AS1 were remarkably increased in LC. Knockdown of FAM83H-AS1 inhibited LC cell proliferation and colony survival fraction. Deletion of FAM83H-AS1 increased the sensitivity of LC cells to 4 Gy of X-ray radiation. In the xenograft model, radiotherapy combined with FAM83H-AS1 silencing significantly reduced tumor volume and weight. Overexpression of FAM83H reversed the effects of FAM83H-AS1 deletion on proliferation and colony survival fraction in LC cells. Moreover, the over-expressing of FAM83H also restored the tumor volume and weight reduction caused by the knockdown of FAM83H-AS1 or radiation in the xenograft model.

CONCLUSION

Knockdown of lncRNA FAM83H-AS1 inhibited LC growth and enhanced radiosensitivity in LC. It has the potential to be a promising target for LC therapy.

Active Immune Phenotype in Head and Neck Cancer: Reevaluating the Iso-Effect Fractionation Based on the Linear Quadratic (LQ) Model-A Narrative Review

Altered fractionation concepts and especially moderate hypo-fractionation are evaluated as alternatives to standard treatment for head and neck squamous cell carcinoma (HNSCC), associated with or not concurrent with or sequential to chemotherapy. The calculation of the iso-equivalent dose regimens has as its starting point the linear quadratic (LQ) formalism traditionally based on the "4Rs" of radiobiology. The higher rates of therapeutic failure after radiotherapy of HNSCC are associated with the heterogeneity of radio-sensibility. The identification of genetic signatures and radio-resistance scores aims to improve the therapeutic ratio of radiotherapy and to conceptualize personalized fractionation schemes. The new data regarding the involvement of the sixth "R" of radiobiology in HNSCC, especially for the HPV-driven subtype, but also for the "immune active" minority of HPV-negative HNSCCs, bring to the fore a multifactorial variation of the α/β ratio. The involvement of the antitumor immune response and the dose/fractionation/volume factors as well as the therapeutic sequence in the case of new multimodal treatments including immune checkpoint inhibitors (ICIs) could be included as an additional term in the quadratic linear formalism especially for hypo-fractionation regimens. This term should take into account the dual immunomodulatory effect (immunosuppressant and stimulator of antitumor immunity) of radiotherapy, which varies from case to case and can bring benefit or a detrimental effect.

Gamma irradiation-induced genetic variability and its effects on the phenotypic and agronomic traits of groundnut (Arachis hypogaeaL.)

In order to increase genetic variability for the improvement of groundnut, two varieties, namely Kp29 and Fleur11, were treated with six different gamma irradiation doses. A significant effect of mutagenesis was distinctly observed in the stem lengths, roots, and survival percentage in both varieties. The radio-sensitivity test showed a mean lethal dose of 436.51Gy for Kp29 and 501.18 Gy for Fleur11. Furthermore, this study revealed putative mutants with variable agro-morphological traits. Seven chlorophyll mutants and various seed shape and color mutants were obtained. This study demonstrates the potency of gamma irradiation to induce high genetic variability that led to the emergence of certain mutations of economic importance.

New horizons in modulating the radio-sensitivity of head and neck cancer - 100 years after Warburg' effect discovery

Tumor radiation resistance along with chemotherapy resistance is one of the main causes of therapeutic failure of radiotherapy-treated head and neck cancers. 100 years after the discovery of the Warburg effect, a process specific to malignant cells to metabolize glucose especially anaerobically even under normoxia condition, its modulation has become a viable therapeutic target for improving the results of cancer therapies. Improving the radio-sensitivity of head and neck tumors by reversing the Warburg effect can increase the rate of local control and reduce the toxicity associated with irradiation. P53 status can be used as a biomarker in the choice of a single agent strategy (cell respiration inhibition with Metformin) or double inhibition, both of respiration and glycolysis. Targeting of enzymes involved in the Warburg effect, such as Hexokinase-II, are strategies with potential to be applied in clinical practice with radio-sensitizing effect for head and neck squamous cell carcinoma. Even if anti-Warburg therapies tested in clinical trials have been associated with either toxic deaths or a minor clinical benefit, the identification of both potential radio-sensitivity biomarkers and methods of reversing the Warburg effect will play an important role in the radiobiology of head and neck cancers.

ITGB5 promotes innate radiation resistance in pancreatic adenocarcinoma by promoting DNA damage repair and the MEK/ERK signaling pathway

Pancreatic adenocarcinoma (PAAD) is one of the most aggressive digestive system tumors in the world, with a low early diagnosis rate and a high mortality. Integrin beta 5 (ITGB5) is demonstrated to be a potent tumor promoter in several carcinomas. However, it is unknown whether ITGB5 participates in the occurrence and development of PAAD. In this study, we confirmed a high expression of ITGB5 in PAAD and its role in promoting invasiveness and transitivity in PAAD. Besides, the knockdown of ITGB5 increased cell sensitivity to radiation by promoting DNA damage repair and the MEK/ERK signaling pathway. Collectively, these results show that ITGB5 plays an essential role in pancreatic cancer growth and survival.

Changes in Radiosensitivity to Gamma-Rays of Lymphocytes from Hyperthyroid Patients Treated with I-131

This study investigated the peripheral blood lymphocytes (PBL) response to a dose of γ-rays in patients treated with radioiodine (I-131) for hyperthyroidism vs. healthy controls, to gain information about the individual lymphocytes’ radio-sensitivity. Blood samples were taken from 18 patients and 10 healthy donors. Phosphorylated histone variant H2AX (γ-H2AX) and micronuclei (MN) induction were used to determine the change in PBL radio-sensitivity and the correlations between the two types of damage. The two assays showed large inter-individual variability in PBL background damage and in radio-sensitivity (patients vs. healthy donors). In particular, they showed an increased radio-sensitivity in 36% and 33% of patients, decrease in 36% and 44%, respectively. There was a scarce correlation between the two assays and no dependence on age or gender. A significant association was found between high radio-sensitivity conditions and induced hypothyroidism. PBL radio-sensitivity in the patient group was not significantly affected by treatment with I-131, whereas there were significant changes inter-individually. The association found between clinical response and PBL radio-sensitivity suggests that the latter could be used in view of the development of personalized treatments.

An 11-Gene Signature Based on Treatment Responsiveness Predicts Radiation Therapy Survival Benefit Among Breast Cancer Patients

Purpose

We developed a strategy of building prognosis gene signature based on clinical treatment responsiveness to predict radiotherapy survival benefit in breast cancer patients.

Methods and Materials

Analyzed data came from the public database. PFS was used as an indicator of clinical treatment responsiveness. WGCNA was used to identify the most relevant modules to radiotherapy response. Based on the module genes, Cox regression model was used to build survival prognosis signature to distinguish the benefit group of radiotherapy. An external validation was also performed.

Results

In the developed dataset, MEbrown module with 534 genes was identified by WGCNA, which was most correlated to the radiotherapy response of patients. A number of 11 hub genes were selected to build the survival prognosis signature. Patients that were divided into radio-sensitivity group and radio-resistant group based on the signature risk score had varied survival benefit. In developed dataset, the 3-, 5-, and 10-year AUC of the signature were 0.814 (CI95%: 0.742–0.905), 0.781 (CI95%: 0.682–0.880), and 0.762 (CI95%: 0.626–0.897), respectively. In validation dataset, the 3- and 5-year AUC of the signature were 0.706 (CI95%: 0.523–0.889) and 0.743 (CI95%: 0.595–0.891). The signature had higher predictive power than clinical factors alone and had more clinical prognosis efficiency. Functional enrichment analysis revealed that the identified genes were mainly enriched in immune-related processes. Further immune estimated analysis showed the difference in distribution of immune micro-environment between radio-sensitivity group and radio-resistant group.

Conclusions

The 11-gene signature may reflect differences in tumor immune micro-environment that underlie the differential response to radiation therapy and could guide clinical-decision making related to radiation in breast cancer patients.

STAT1 mediated long non-coding RNA LINC00504 influences radio-sensitivity of breast cancer via binding to TAF15 and stabilizing CPEB2 expression

Radiotherapy plays important roles in the treatment of breast cancer (BC), which develops from malignant cells in the breast. Long non-coding RNAs (lncRNAs) have been reported to be implicated in radio-resistance or radio-sensitivity of human cancer, which includes breast cancer. Nevertheless, long intergenic non-protein coding RNA 0504 (LINC00504) has not been investigated in BC. In our study, from RT-qPCR analysis, LINC00504 was found to be up-regulated in BC cells. By conducting in vitro assays, it was confirmed that the knockdown of LINC00504 could enhance the radio-sensitivity of BC cells. The regulatory mechanism of LINC00504 in BC was also verified by chromatin immunoprecipitation (ChIP), RNA immunoprecipitation (RIP) and luciferase reporter assays. From the experimental results, we knew that the up-regulation of LINC00504 was mediated by signal transducer and activator of transcription 1 (STAT1). Moreover, LINC00504 stabilized the expression of cytoplasmic polyadenylation element-binding protein 2 (CPEB2) via binding to TATA-box binding protein associated factor 15 (TAF15). Furthermore, rescue assays validated that LINC00504 participated in regulating the radio-sensitivity of BC cells via up-regulating CPEB2. In summary, our study disclosed that STAT1 could mediate LINC00504 and weaken the radio-sensitivity of BC cells via binding to TAF15 and stabilizing CPEB2 expression.

PLAC8 gene knockout increases the radio-sensitivity of xenograft tumors in nude mice with nasopharyngeal carcinoma by promoting apoptosis

In vitro cell experiments showed that knocking out the placenta-specific protein 8 (PLAC8) gene significantly increased the sensitivity of tumor cells to radiation. This study used two nude mouse models of nasopharyngeal carcinoma (NPC) to investigate the radio-sensitization and molecular mechanism of PLAC8 knockout in vivo. The expression of PLAC8 in 120 NPC tissues and 30 nasopharyngitis (NPG) tissues was detected by immunohistochemistry (IHC) to analyze the relationship between PLAC8 and neck lymph node metastasis and prognosis in NPC patients. The mRNA expression level of PLAC8 in several NPC cell lines was detected by semi-quantitative RT-PCR. The PLAC8 gene was knocked out in CNE-2 cells using CRISPR/Cas9. The effect of PLAC8 gene knockout on the radiotherapy sensitivity of NPC cells was analyzed by establishing model 1 and model 2 tumor-bearing nude mouse models with two different irradiation methods. The expression of γH2AX, Bax, Bcl-2, Caspase-3 and cleaved Caspase-3 was detected by immunofluorescence (IF), IHC and western blot analysis. PLAC8 expression was significantly increased in NPC tissue samples and NPC cell lines compared with NPG tissue samples and normal cell lines (P<0.01). PLAC8 upregulation was associated with lymph node metastasis and a poor prognosis in patients with NPC (P<0.01). Both animal models showed that radiotherapy after PLAC8 knockout significantly slowed tumor growth and reduced tumor volume, with tumor inhibition rates of 100% and 66.04%, respectively. In model 2, PLAC8 knockout with radiotherapy increased the expressions of γH2AX, Bax, Caspase-3 and cleaved Caspase-3 but decreased the expression of Bcl-2 (P<0.01). In model 1, there was no tumor formation at the site where the cancer cells were injected. The expression levels of γH2AX, Bax, Caspase-3 and cleaved Caspase-3 in skin tissues taken at the injection site were lower than those in NPC tissues treated with radiotherapy, while the expression level of Bcl-2 was higher (P<0.01). PLAC8 expression is closely related to neck metastasis and the prognosis of NPC. PLAC8 gene knockout significantly increases the radio-sensitivity of NPC cells in vivo by promoting apoptosis, which is an effective strategy for the radiotherapy sensitization of NPC.

Silencing UCHL3 enhances radio-sensitivity of non-small cell lung cancer cells by inhibiting DNA repair

UCHL3 belongs to the UCH family and is involved in multiple biological processes. However, the biological functions and underlying mechanisms of action of UCHL3 in radio-sensitivity of non-small cell lung cancer (NSCLC) remain unknown. Here, we reported that the expression of UCHL3 was significantly up-regulated in NSCLC tissues and cell lines, and associated with poor prognosis of NSCLC patients. The expression of UCHL3 of NSCLC cells was increased after exposure to ionizing radiation (IR). Moreover, we found that knockdown of UCHL3 enhanced the radio-sensitivity of NSCLC cells both in vitro and in vivo. Furthermore, γH2AX foci staining and Western blot analysis showed that knockdown of UCHL3 increased IR-induced DNA damage. Knockdown of UCHL3 in NSCLC cells decreased homologous recombination (HR) repair efficiency and RAD51 foci formation. Collectively, our study revealed that knockdown of UCHL3 enhanced the radio-sensitivity of NSCLC cells and increased IR-induced DNA damage via impairing HR repair.

Preparation of an experimental mouse model lacking selenium-dependent glutathione peroxidase activities by feeding a selenium-deficient diet

Relatively young (4-week-old) selenium deficient (SeD) mice, which lack the activity of selenium-dependent glutathione peroxidase (GSH-Px) isomers, were prepared using torula yeast-based SeD diet. Mice were fed the torula yeast-based SeD diet and ultra-pure water. Several different timings for starting the SeD diet were assessed. The weekly time course of liver comprehensive GSH-Px activity after weaning was monitored. Protein expression levels of GPx1 and 4 in the liver were measured by Western blot analysis. Gene expression levels of GPx1, 2, 3, 4, and 7 in the liver were measured by quantitative real-time PCR. Apoptotic activity of thymocytes after hydrogen peroxide (H2O2) exposure was compared. Thirty-day survival rates after whole-body X-ray irradiation were estimated. Pre-birth or right-after-birth starting of the SeD diet in dams was unable to lead to creation of SeD mice due to neonatal death. This suggests that Se is necessary for normal birth and healthy growing of mouse pups. Starting the mother on the SeD diet from 2 weeks after giving birth (SeD-trial-2w group) resulted in a usable SeD mouse model. The liver GSH-Px activity of the SeD-trial-2w group was almost none from 4 week olds, but the mice survived for more than 63 weeks. Protein and gene expression of GPx1 was suppressed in the SeD-trial-2w group, but that of GPx4 was not. The thymocytes of the SeD-trial-2w group were sensitive to H2O2-induced apoptosis. The SeD-trial-2w group was sensitive to whole-body X-ray irradiation compared with control mice. The SeD-trial-2w model may be a useful animal model for H2O2/hydroperoxide-induced oxidative stress.

Prospects for Radiopharmaceuticals as Effective and Safe Therapeutics in Oncology and Challenges of Tumor Resistance to Radiotherapy

The rapid advances in nuclear medicine have resulted in significant advantages for the field of oncology. The focus is on the application of radiopharmaceuticals as therapeuticals. In addition, the latest developments in cell biology (the understanding of the cell structure, function, metabolism, genetics, signaling, transformation) have given a strong scientific boost to radiation oncology. In this regard, the article discusses what is soon going to be a new jump in radiation oncology based on the already accumulated considerable knowledge at the cellular level about the mechanisms of cell transformation and tumor progression, cell response to radiation, cell resistance to apoptosis and radiation and cell radio-sensitivity. The mechanisms of resistance of tumor cells to radiation and the genetically determined individual sensitivity to radiation in patients (which creates the risk of radiation-induced acute and late side effects) are the 2 major challenges to overcome in modern nuclear medicine. The paper focuses on these problems and makes a detailed summary of the significance of the differences in the ionizing properties of radiopharmaceuticals and the principle of their application in radiation oncology that will shed additional light on how to make the anti-cancer radiotherapies more efficient and safe, giving some ideas for optimizations.

FOXG1 mediates the radiosensitivity of glioma cells through regulation of autophagy

BACKGROUND/AIM

Upregulation of Forkhead box G1 (FOXG1) has recently been observed in many cancers, while its effect on radiosensitivity in glioma is still unclear. In this study, we hypothesized that FOXG1 be a major player in radioresistance of glioma as well as the underlying mechanism.

METHODS

Immunohistochemistry (IHC) was conducted to assess FOXG1 expression in glioma tissues and glioma-adjacent tissues. Western Blot was implemented to detect the expression of autophagy-related proteins. CCK-8, colony formation and flow cytometry assays were implemented to assess cell viability, proliferation and apoptosis, respectively. Transmission electron microscope (TEM) was used to observe autophagic vesicles. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) assay was applied to detect the expression of FOXG1.

RESULTS

The present study demonstrated that FOXG1 was highly expressed in glioma tissues. FOXG1 expression level was up-regulated in glioma cells following exposure to X-ray irradiation. FOXG1 can attenuate radiosensitivity of glioma cells. Moreover, it revealed that FOXG1 attenuate radiosensitivity of glioma cells by promoting autophagy.

CONCLUSIONS

The present study suggests that FOXG1 is a pivotal molecule for circumventing radiation-induced cell death in malignant glioma cells through the regulation of autophagy, and it may be a target for the treatment of human brain glioma.

miR-4270 Modulates the Irradiation-Sensitivity of Nasopharyngeal Carcinoma Cells through Modulation of p53 in Vivo

The lowered sensitivity to irradiation considerably impacted on the prognosis of nasopharyngeal carcinoma treatments. This study aimed to explore the functions of miR-4270 in nasopharyngeal carcinoma. Bioinformatic analysis was performed online accessing GSE139164 dataset to screen the top 30 differential microRNAs in nasopharyngeal carcinoma patients with radio-sensitivity. Cancer cell lines, 6-10B and 5-8F, were cultured and measured for expression of miR-4270 and TP53 (the gene of the tumor suppressor protein p53) with the normal nasopharyngeal epithelial cells as a control. The miR-4270 expression was regulated in cells via the introduction of miR-4270 inhibitor or mimic in different concentrations (25, 50, 100 nmol/L). Targetscan predicted the target of miR-4270 and the bindings while luciferase was used to confirm this. CCK8 methods were used to evaluate the irradiation sensitivity of the cells after exposure to increasing X-Ray irradiation. RT-PCR detected the RNA expression and Western blot examined the protein expression of p53. Flow cytometry detected the cell apoptosis rates respectively. miR-4270 is among the top differential microRNAs between the radio-sensitive and -resistant patients. In vivo, miR-4270 expression was lower in cancer cell lines. The inhibition of miR-4270 raised the cell sensitivity to irradiation. miR-4270 negatively mediated TP53 and targeted TP53. Additionally, p53 increased cell sensitivity to irradiation and modulated by miR-4270 in nasopharyngeal carcinoma cells. In conclusion, this study first reports that miR-4270 is lower in the radio-sensitive patients and modulated the irradiation-sensitivity of nasopharyngeal carcinoma cells through modulation of p53 in vivo.

A Comprehensive Analysis of Alterations in DNA Damage Repair Pathways Reveals a Potential Way to Enhance the Radio-Sensitivity of Esophageal Squamous Cell Cancer

Esophageal squamous cell cancer (ESCC) is a common malignancy with a poor 5-year overall survival in China. Altered DNA damage repair (DDR) pathways are associated with a predisposition to cancer and contribute to therapeutic response and resistance in cancers. However, alterations of DDR pathway genes in ESCC are still largely unknown. In this study, we employed genome sequencing data of 192 samples, comparative genomic hybridization data of 123 cases, and gene expression microarray data of 119 patients to firstly perform a comprehensive analysis of the gene alterations of 7 DDR pathways in ESCC. Gene mutations and copy number variations (CNVs) were observed in all 7 DDR pathways, and especially, CNVs were the dominant alteration types. Compared with other pathways, two DNA double-strand break (DSB) repair pathways homologous recombination (HR) and non-homologous end joining (NHEJ), carried significant gene mutations and CNVs especially gene amplifications. Most genes including RAD54B, NBS1, RAD51B, and PRKDC were significantly amplified and over-expressed in ESCC. Amplification and high expression of DSB repair pathway genes were associated with poorer overall survival. Gene set variation analysis further showed that DSB repair pathways were up-regulated in ESCC. Besides, we firstly demonstrated that combination of mirin and NU7441, two inhibitors for HR and NHEJ respectively, with ionizing radiation treatment significantly enhanced DSBs, reduced clonogenic cell survival, inhibited cell proliferation, and promoted cell apoptosis in ESCC cells with DSB pathway gene amplification. These findings suggest that DSB repair pathways were significantly altered in ESCC and inhibiting DSB repair pathways might enhance the radio-sensitivity of ESCC with DSB repair up-regulation.

Inhibition of Wnt signalling pathway by XAV939 enhances radiosensitivity in human cervical cancer HeLa cells

Cervical cancer is the second most common malignant tumour threatening women's health. In recent years, heavy-ion beam therapy is becoming a newly emerging therapeutic mean of cancer; however, radio-resistance and radiation-induced damage constitute the main obstacles for curative treatment of cervical cancer. Therefore, to identify the radiosensitizers is essential. Here, we investigated the effects of Wnt signalling pathway on the response of ¹²C⁶⁺ radiation in HeLa cells. XAV939, an inhibitor of Wnt signalling pathway, was added two hours before ¹²C⁶⁺ radiation.¹²C⁶⁺ radiation inhibited the viability of HeLa cells in a time-dependent manner, and inhibiting Wnt signalling using XAV939 significantly intensified this stress. Meanwhile, ¹²C⁶⁺ radiation induced a significant increased cell apoptosis, G2/M phase arrest, and the number of γ-H2AX foci. Supplementation with XAV939 significantly increased the effects induced by ¹²C⁶⁺ radiation alone. Combining XAV939 with ¹²C⁶⁺ irradiation, the expression of apoptotic genes (p53, Bax, Bcl-2) was significantly increased, while the expression of Wnt-related genes (Wnt3a, Wnt5a, β-catenin, cyclin D1 and c-Myc) was significantly decreased. Overall, these findings suggested that blockage of the Wnt/β-catenin pathway effectively sensitizes HeLa cells to ¹²C⁶⁺ irradiation, and it may be a potential therapeutic approach in terms of increasing the clinical efficacy of ¹²C⁶⁺ beams.

Silencing of lncRNA LINC00857 Enhances BIRC5-Dependent Radio-Sensitivity of Lung Adenocarcinoma Cells by Recruiting NF-κB1

Lung adenocarcinoma (LUAD) is a predominant type of lung cancer in never-smoker patients. In this study, we identified a long noncoding RNA (lncRNA) LINC00857 that might regulate radio-sensitivity of LUAD cells. Expression of LINC00857 and baculoviral IAP repeat containing 5 (BIRC5) was determined to be upregulated in LUAD cells and tissues using qRT-PCR and western blot analysis. The correlation between LINC00857 and nuclear factor kappa B subunit 1 (NF-κB1) was verified using RNA immunoprecipitation and chromatin immunoprecipitation assays, while the binding relationship between NF-κB1 and BIRC5 was determined by dual-luciferase reporter assay. It was suggested that LINC00857 could recruit NF-κB1 in BIRC5 promoter region. BIRC5 promoter activity was repressed in response to small interfering-LINC00857 (si-LINC00857) in LUAD cells. Silencing LINC00857 or BIRC5 reduced proliferation and colony formation but enhanced apoptosis and radio-sensitivity of LUAD cells. The experiment in vivo verified the function of silencing LINC00857 on enhancing radio-sensitivity of LUAD cells. Our results reveal a functional regulatory LINC00857-NF-κB1-BIRC5 triplet in LUAD cells, suggesting LINC00857 as a potential target for LUAD treatment.

A gene expression signature for predicting response to neoadjuvant chemoradiotherapy in pancreatic ductal adenocarcinoma

In patients with pancreatic ductal adenocarcinoma (PDAC), optimal treatment selection, including multimodality regimens such as neoadjuvant chemoradiotherapy (NACRT), can be clinically transformative. Unfortunately, currently no predictive biomarkers are available that can guide the use of NACRT in PDAC patients. Accordingly, herein we developed a novel gene signature that can preoperatively predict NACRT-sensitivity in PDAC patients. Herein, we evaluated the performance of a 10-gene panel in 749 PDAC cases, which included two public datasets (The Cancer Genome Atlas and International Cancer Genome Consortium; n = 276), and three clinical specimen cohorts (n = 417), and a pre-NACRT endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) biopsy cohort (n = 56). The potential predictive performance of this signature was evaluated and compared to CA-19-9 levels and key clinicopathological factors. We first evaluated the prognostic potential of a 10-gene panel which significantly predicted overall survival in both public datasets (P < .01, P < .01), and two in-house patient cohorts (P < .01, P = .04). In the pre-NACRT EUS-FNA cohort, we established a radio-sensitivity gene panel (RSGP) which yielded highly robust (area under the curve [AUC] = 0.91; 95% CI: 0.81-0.97) for predicting response to gemcitabine-based NACRT. Multivariate logistic regression analysis revealed that RSGP was an independent predictor for response to NACRT (OR = 2.70; 95% CI: 1.25-5.85), and this response-prediction was even more robust when CA-19-9 levels were included into the model. In conclusion, we have validated and developed a novel gene signature that is highly robust in predicting response to NACRT, even in preoperative settings, highlighting its clinical significance for optimizing and personalizing treatment strategies in PDAC patients.

The effects of the Wnt/β‑catenin signaling pathway on apoptosis in HeLa cells induced by carbon ion irradiation

The molecular mechanisms underlying the biological effects of carbon ions are unclear. The aim of this study was to explore the Wnt/β‑catenin pathway in regulating carbon ion (12C6+) radiation‑induced cellular toxicity. HLY78 is a Wnt‑specific small molecular modulator, whose effects on 12C6+ radiation‑induced damage are mostly unknown. HLY78, in combination with 12C6+ radiation was investigated on HeLa cell viability, cell cycle progression, DNA damage, and the expression of apoptotic and Wnt‑related proteins. 12C6+ radiation suppressed cell viability in a time‑dependent manner, whereas the addition of HLY78 to cells significantly reduced this stress. Moreover, after irradiation with 12C6+, HeLa cells exhibited increased cell apoptosis, G2/M phase arrest, and a number of γ‑H2AX foci. However, Wnt signaling activation alleviated these effects. Furthermore, when compared with the radiation alone group, supplementation with HLY78 markedly increased the expression of anti‑apoptotic and Wnt‑related proteins, and significantly decreased the expression of apoptotic proteins. The present results indicated that activation of the Wnt/β‑catenin signaling pathway by HLY78 reduced 12C6+ radiation‑induced HeLa cell dysfunction, suggesting that the Wnt/β‑catenin signaling pathway plays an important role in regulating 12C6+ radiation‑induced cellular toxicity in HeLa cells.

The Effect of PEI-Mediated E1A on the Radiosensitivity of Hepatic Carcinoma Cells

Objective:

The study was undertaken to investigate the effects of polyethyleneimine (PEI)-mediated adenovirus 5 early region 1A (E1A) on radiosensitivity of human hepatic carcinoma cell in vitro and to disclosure the underlying mechanism.

Materials and Methods:

Human hepatic carcinoma SMMC-7721 cell line was transfected with E1A gene using PEI vector. Untransfected cells (SMMC-7721 group), cells transfected with blank-vector (SMMC-7721-vect group), and cells transfected with E1A gene (SMMC-7721-E1A group) were treated with 6 MV X-ray irradiation at doses of 0, 1, 2, 4, 8 and Gy, respectively. Radiosensitivity was determined by MTT assay and quantified by calculating the cell survival rate. Cell-cycle distribution and apotosis rate were monitored by flow cytometry.

Results:

The survival rate of SMMC-7721-E1A was significantly lower than that of SMMC-7721 cell. Apoptosis rate of SMMC-7721-E1A group was significantly higher than that of SMMC-7721group (P<0.01).The ratio of S stage in cell cycle of SMMC-7721-E1A was significantly lower than that in SMMC-7721 cell. The ratio of G2/M stage in cell cycle of SMMC-7721-E1A was significantly higher than that in SMMC-7721 cell (P<0.01).

Conclusion:

PEI could transfect E1A gene into hepatic carcinoma cells PEI-mediated E1A could effectively enhance radiosensitivity of hepatic carcinoma cells which may be related to its effects on apoptosis promoting leading to S phase suppression and G2/M phase arrest.

MiR-193b-5p inhibits proliferation and enhances radio-sensitivity by downregulating the AKT/mTOR signaling pathway in tongue cancer

BACKGROUND

MicroRNAs (miRNAs) have been found to have functions regulating cell proliferation, differentiation and apoptosis, thereby regulating the occurrence, development and prognosis of tumors. MiR-193b-3p is well-known for its tumorigenic effect, but there are few studies on miR-193b-5p, and its role in tongue cancer has not been reported.

METHODS

In the present research, we investigated the specific role of miR-193b-5p in tongue cancer. MiR-193b-5p mimics were transfected into tongue cancer cell lines CAL27 and TCA-8113 to generate miR-193b-5p overexpression cells. CCK-8, clonogenic assay, wound healing assay, transwell and flow cytometry analysis were performed to detect cell proliferation, migration, invasion and apoptosis.

RESULTS

Our data showed that the exogenous overexpression of miR-193b-5p blocked the proliferation, inhibited the phosphorylation of AKT and mTOR, and downregulated the levels of Cyclin D1 and P70 of CAL27 and TCA-8113 cells. We predicted that miR-193b-5p suppressed the proliferation of cancer cells by inhibiting the AKT/mTOR pathway. MiR-193b-5p mimics also induced the apoptosis of CAL27 and TCA-8113 cells by inhibiting the expression of Bcl2 and promoting the levels of Active-Caspase3 and Bax. Furthermore, a marked decline in the migration and invasiveness of tongue cancer cells transected with miR-193b-5p mimics was observed. According to the results of western blot, miR-193b-5p downregulated the levels of the epithelial-to-mesenchymal transition (EMT) markers, including N-cad, Vimentin, Snail and Slug, while upregulating E-cad expression level in CAL27 and TCA-8113 cells, suggesting that miR-193b-5p inhibited the migration and invasion by reversing the EMT process. In addition, miR-193b-5p mimics inhibited the formation of clonogenic colonies of CAL27 and TCA-8113 cells after irradiation.

CONCLUSIONS

Taken together, miR-193b-5p mimics block cell proliferation, migration and invasion and induce apoptosis by inhibiting the AKT/mTOR signaling pathway; they also reversed EMT progression and inhibited the radio-resistance of tongue cancer cells. Our results provide a potential target for the clinical treatment of human tongue cancer.

Knockdown of SMAD3 inhibits the growth and enhances the radiosensitivity of lung adenocarcinoma via p21 in vitro and in vivo

Radiotherapy is an effective approach for the treatment of lung adenocarcinoma. However, evidence suggests that lung adenocarcinoma can easily develop tolerance to radiotherapy. The purpose of this study was to investigate the effect and mechanism of SMAD3 on the radiosensitivity of lung adenocarcinoma in vitro and in vivo. We found that knockdown of SMAD3 using two short hairpin RNAs in lentivirus vectors significantly inhibited cell growth and increased radiosensitivity of the lung adenocarcinoma cell lines A549, H1299, and H1975. Using RNA sequencing and bioinformatics analyses, we found that the significantly differentially expressed genes in SMAD3 knockdown cells were mainly enriched in the cell cycle process. We then showed that knockdown of SMAD3 significantly reduced expression of cyclin-dependent kinase inhibitor 1 (p21) and increased the proportion of G2/M phase cells and the radiosensitivity of lung adenocarcinoma. Chromatin immunoprecipitation results in the Gene Expression Omnibus (GEO) database and our luciferase assay verified that SMAD3 directly bound the p21 promoter. A series of rescue experiments showed that overexpression of p21 partly reversed the effect of SMAD3 on proliferation and radioresistance in vitro and in vivo. Moreover, we found that the expression levels of SMAD3 and p21 were highly correlated, and both correlated with the patients' survival in online databases and clinical specimens. Expression of SMAD3 and p21 was also significantly different between radioresistant and radiosensitive patients in our hospital. Our results indicate that SMAD3 is a potential prognosis and radiosensitivity indicator as well as a target for radiotherapy and other treatments of patients with lung adenocarcinoma.

Down-regulation of TFAM increases the sensitivity of tumour cells to radiation via p53/TIGAR signalling pathway

Mitochondrial transcription factor A (TFAM) is a key regulator of mitochondria biogenesis. Previous studies confirmed that reduced TFAM expression sensitized tumours cells to chemical therapy reagents and ionizing irradiation (IR). However, the underlying mechanisms remain largely unknown. In this study, we identified that decreased expression of TFAM impaired the proliferation of tumour cells by inducing G1/S phase arrest and reducing the expression of E2F1, phospo‐Rb, PCNA and TK1. Furthermore, we proved that knockdown of TFAM enhanced the interaction between p53 and MDM2, resulting in decreased expression of p53 and the downstream target TIGAR, and thus leading to elevated level of mitochondrial superoxide and DNA double‐strand break (DSB) which were exacerbated when treated the cell with ionizing radiation. Those indicated that knockdown of TFAM could aggravate radiation induced DSB levels through affecting the production of mitochondria derived reactive oxygen species. Our current work proposed a new mechanism that TFAM through p53/TIGAR signalling to regulate the sensitivity of tumour cells to ionizing radiation. This indicated that TFAM might be a potential target for increasing the sensitization of cancer cells to radiotherapy.

PACE: A Probabilistic Atlas for Normal Tissue Complication Estimation in Radiation Oncology

In radiation oncology, the need for a modern Normal Tissue Complication Probability (NTCP) philosophy to include voxel-based evidence on organ radio-sensitivity (RS) has been acknowledged. Here a new formalism (Probabilistic Atlas for Complication Estimation, PACE) to predict radiation-induced morbidity (RIM) is presented. The adopted strategy basically consists in keeping the structure of a classical, phenomenological NTCP model, such as the Lyman-Kutcher-Burman (LKB), and replacing the dose distribution with a collection of RIM odds, including also significant non-dosimetric covariates, as input of the model framework. The theory was first demonstrated in silico on synthetic dose maps, classified according to synthetic outcomes. PACE was then applied to a clinical dataset of thoracic cancer patients classified for lung fibrosis. LKB models were trained for comparison. Overall, the obtained learning curves showed that the PACE model outperformed the LKB and predicted synthetic outcomes with an accuracy >0.8. On the real patients, PACE performance, evaluated by both discrimination and calibration, was significantly higher than LKB. This trend was confirmed by cross-validation. Furthermore, the capability to infer the spatial pattern of underlying RS map for the analyzed RIM was successfully demonstrated, thus paving the way to new perspectives of NTCP models as learning tools.

Cyclooxygenase-2-Mediated Up-Regulation of Mitochondrial Transcription Factor A Mitigates the Radio-Sensitivity of Cancer Cells

Mitochondrial transcription factor A (TFAM) regulates mitochondrial biogenesis, and it is a candidate target for sensitizing tumor during therapy. Previous studies identified that increased TFAM expression conferred tumor cells resistance to ionizing radiation. However, the mechanisms on how TFAM are regulated in irradiated tumor cells remain to be explored. In this research, we demonstrated the contribution of cyclooxygenase-2 (COX-2) to enhancing TFAM expression in irradiated tumor cells. Our results showed TFAM was concomitantly up-regulated with COX-2 in irradiated tumor cells. Inhibition of COX-2 by NS-398 blocked radiation-induced expression of TFAM, and prostaglandin E2 (PGE2) treatment stimulated TFAM expression. We next provided evidence that DRP1-mediated mitochondrial fragmentation was a reason for TFAM up-regulation in irradiated cells, by using small interfering RNA (siRNA) and selective inhibitor-targeted DRP1. Furthermore, we proved that p38-MAPK-connected COX-2, and DRP1-mediated TFAM up-regulation. Enhanced phosphorylation of p38 in irradiated tumor cells promoted DRP1 expression, mitochondrial fragmentation, and TFAM expression. NS-398 treatment inhibited radiation-induced p38 phosphorylation, while PGE2 stimulated the activation of p38. The results put forward a mechanism where COX-2 stimulates TFAM expression via p38-mediated DRP1/mitochondrial fragmentation signaling in irradiated tumor cells, which may be of value in understanding how to sensitize cancer cells during radiotherapy.

LncRNA H19 interacted with miR-130a-3p and miR-17-5p to modify radio-resistance and chemo-sensitivity of cardiac carcinoma cells

The current investigation explored the synthetic contribution of lncRNA H19, miR-130a-3p, and miR-17-5p to radio-resistance and chemo-sensitivity of cardiac cancer cells. Totally 284 human cardiac cancer tissues were gathered, and they have been pathologically diagnosed. The cardiac cancer cells were isolated with utilization of the mechanic method. Moreover, cisplatin, adriamycin, mitomycin, and 5-fluorouracil were designated as the chemotherapies, and single-dose X-rays were managed as the radiotherapy for cardiac cancer cells. We also performed luciferase reporter gene assay to verify the targeted relationship between H19 and miR-130a-3p, as well as between H19 and miR-17-5p. Finally, mice models were established to examine the functions of H19, miR-130a-3p, and miR-17-5p on the development of cardiac cancer. The study results indicated that H19, miR-130a-3p, and miR-17-5p expressions within cardiac cancer tissues were significantly beyond those within adjacent nontumor tissues (P < 0.05), and H19 expression was positively correlated with both miR-130a-3p (r_s  = 0.43) and miR-17-5p (r_s  = 0.49) expressions. The half maximal inhibitory concentrations (IC50) of cisplatin, adriamycin, mitomycin, and 5-fluorouracil for cardiac cancer cells were, respectively, determined as 2.01 μg/mL, 8.35 μg/mL, 24.44 μg/mL, and 166.42 μg/mL. The overexpressed H19, miR-130a-3p, and miR-17-5p appeared to improve the survival rate and viability of cardiac cancer cells that were exposed to chemotherapies and X-rays (all P < 0.05). It was also drawn from luciferase reporter gene assay that H19 could directly target miR-130a-3p and miR-17-5p, thereby modifying the sensitivity of cardiac cancer cells to drugs and X-rays (P < 0.05). Finally, the mice models also produced larger tumor size and higher tumor weight, when H19, miR-130a-3p, or miR-17-5p expressions were up-regulated within them (P < 0.05). In conclusion, H19 could act on miR-130a-3p or miR-17-5p to alter the radio- and chemo-sensitivities of cardiac cancer cells, helping to improve the radio-/chemotherapies for cardiac cancer.

The pivotal role of DNA methylation in the radio-sensitivity of tumor radiotherapy

Radiotherapy is an important modality for treatment of carcinomas; however, radio‐resistance is still a difficult problem. Aberrant epigenetic alterations play an important role in cancer development. Among epigenetic parameters, DNA methylation has arguably attracted the most attention in the radio‐resistance process. To determine the role of DNA methylation in radiation resistance, several studies were conducted. We summarized previous studies on the role of DNA methylation in radiotherapy. We observed this significant role of DNA methylation in genes related to DNA repair, cell proliferation, cell cycle process, and re‐oxygenation. Furtherly, we also conclude the predictive effect of DNA methylation on tumor radio‐sensitivity and the using of DNA methyltransferase inhibitors in clinical practice. DNA methylation plays a pivotal role in the radio‐sensitivity of tumor radio‐therapy. While hyper‐methylation or hypo‐methylation of genes is related to gene functions.

Insulin-like growth factor-1 receptor knockdown enhances radiosensitivity via the HIF-1α pathway and attenuates ATM/H2AX/53BP1 DNA repair activation in human lung squamous carcinoma cells

Insulin-like growth factor-1 receptor (IGF-1R) is a cell membrane receptor involved in cell proliferation and apoptosis, which is highly expressed in lung squamous cell carcinoma (SCC). The present study aimed to observe the influence of IGF-1R silencing on the radiosensitivity of SCC and investigate the potential mechanisms involved. Human lung SCC H520 cells with relatively high expression of IGF-1R were used. IGF-1R expression was silenced using short hairpin RNA. The influence of IGF-1R silencing on radiosensitivity and apoptosis was assessed using a clone formation assay and flow cytometry. The expression levels of proteins relevant in DNA damage repair and hypoxic signaling pathways were analyzed using western blotting. Decreased expression of IGF-1R led to an increase in the sensitivity of H520 cells to irradiation. Molecular analysis showed that the reduced expression of IGF-1R decreased the protein expression of ataxia-telangiectasia mutated (ATM), H2A histone family member X (H2AX) and p53 binding protein 1 (53BP1), which are associated with the DNA repair pathway. Furthermore, 53BP1 is also known to be involved in apoptosis. Proteins involved in the hypoxic pathway, including hypoxia inducible factor 1 α (HIF-1α), matrix metallopeptidase 9 (MMP-9) and vascular endothelial growth factor A (VEGFA) were also involved in the radiosensitivity. In conclusion, decreased expression of IGF-1R leads to improved radiosensitivity of SCC cells, and the underlying mechanism may be associated with the decreased expression of proteins involved in ATM/H2AX/53BP1 DNA damage repair and the HIF-1α/MMP-9 hypoxic pathway, which results in the induction of apoptosis and increased radiosensitivity. These findings suggest that targeting of IGF-1R may represent a novel approach for lung SCC radiation treatment.

Development of a radiosensitivity gene signature for patients with soft tissue sarcoma

Adjuvant radiotherapy is an important clinical treatment option for the majority of sarcomas. The motivation of current study is to identify a gene signature and to predict radiosensitive patients who are most likely to benefit from radiotherapy. Using the public available data of soft tissue sarcoma from The Cancer Genome Atlas, we developed a cross-validation procedure for identifying a gene signature and predicting radiosensitive patients through. The result showed that the predicted radiosensitive patients who received radiotherapy had a significantly better survival with a reduced rate of new tumor event and disease progression. Strata analysis showed that the predicted radiosensitive patients had significantly better survival under radiotherapy independent of histologic types. A hierarchical cluster analysis was used to validate the gene signature, and the results showed the predicted sensitivity for each patient well matched the results from cluster analysis. Together, we demonstrate a radiosensitive molecular signature that can be potentially used for identifying radiosensitive patients with sarcoma.

MicroRNA-9 functions as a tumor suppressor and enhances radio-sensitivity in radio-resistant A549 cells by targeting neuropilin 1

Radiotherapy is commonly used to treat lung cancer but may not kill all cancer cells, which may be attributed to the radiotherapy resistance that often occurs in non-small cell lung cancer (NSCLC). At present, the molecular mechanism of radio-resistance remains unclear. Neuropilin 1 (NRP1), a co-receptor for vascular endothelial growth factor (VEGF), was demonstrated to be associated with radio-resistance of NSCLC cells via the VEGF-phosphoinositide 3-kinase-nuclear factor-κB pathway in our previous study. It was hypothesized that certain microRNAs (miRs) may serve crucial functions in radio-sensitivity by regulating NRP1. Bioinformatics predicted that NRP1 was a potential target of miR-9, and this was validated by luciferase reporter assays. Functionally, miR-9-transfected A549 cells exhibited a decreased proliferation rate, increased apoptosis rate and attenuated migratory and invasive abilities. Additionally, a high expression of miR-9 also significantly enhanced the radio-sensitivity of A549 cells in vitro and in vivo. These data improve understanding of the mechanisms of cell radio-resistance, and suggest that miR-9 may be a molecular target for the prediction of radio-sensitivity in NSCLC.

Inorganic polyphosphate enhances radio-sensitivity in a human non-small cell lung cancer cell line, H1299

Inorganic polyphosphate is a linear polymer containing tens to hundreds of orthophosphate residues linked by high-energy phosphoanhydride bonds. Polyphosphate has been recognized as a potent anti-metastasis reagent. However, the molecular mechanism underlying polyphosphate action on cancer cells is poorly understood. In this study, we investigated the involvement of polyphosphate in radio-sensitivity using a human non-small cell lung cancer cell line, H1299. We found that polyphosphate treatment decreases cellular adenosine triphosphate levels, suggesting a disruption of energy metabolism. We also found that the induction of DNA double-strand breaks was enhanced in polyphosphate-treated cells after X-ray irradiation and colony formation assay revealed that cell survival decreased compared with that of the control groups. These findings suggest that polyphosphate is a promising radio-sensitizer for cancer cells. Therefore, we hypothesized that polyphosphate treatment disrupts adenosine triphosphate-mediated energy transfer for cellular survival and DNA repair, thereby reducing the cellular capability to resist X-ray irradiation.

Regulation of Cancer Cell Responsiveness to Ionizing Radiation Treatment by Cyclic AMP Response Element Binding Nuclear Transcription Factor

Cyclic AMP response element binding (CREB) protein is a member of the CREB/activating transcription factor (ATF) family of transcription factors that play an important role in the cell response to different environmental stimuli leading to proliferation, differentiation, apoptosis, and survival. A number of studies highlight the involvement of CREB in the resistance to ionizing radiation (IR) therapy, demonstrating a relationship between IR-induced CREB family members' activation and cell survival. Consistent with these observations, we have recently demonstrated that CREB and ATF-1 are expressed in leukemia cell lines and that low-dose radiation treatment can trigger CREB activation, leading to survival of erythro-leukemia cells (K562). On the other hand, a number of evidences highlight a proapoptotic role of CREB following IR treatment of cancer cells. Since the development of multiple mechanisms of resistance is one key problem of most malignancies, including those of hematological origin, it is highly desirable to identify biological markers of responsiveness/unresponsiveness useful to follow-up the individual response and to adjust anticancer treatments. Taking into account all these considerations, this mini-review will be focused on the involvement of CREB/ATF family members in response to IR therapy, to deepen our knowledge of this topic, and to pave the way to translation into a therapeutic context.

Spatio-temporal changes in glutathione and thioredoxin redox couples during ionizing radiation-induced oxidative stress regulate tumor radio-resistance

Ionizing radiation (IR)-induced oxidative stress in tumor cells is effectively managed by constitutive and inducible antioxidant defense systems. This study was initiated to understand the relative contribution of different redox regulatory systems in determining the tumor radio-resistance. In this study, human T-cell lymphoma (Jurkat) cells were exposed to IR (4 Gy) and monitored for the spatio-temporal changes in cellular redox regulatory parameters. We monitored the changes in the levels of reactive oxygen species (ROS) (total, mitochondrial, primary, and secondary), thiols (total, surface, and intracellular), GSH/GSSG ratio, antioxidant enzyme activity viz. thioredoxin (Trx), Trx reductase (TrxR), glutathione peroxidase, and glutathione reductase with respect to time. We have also measured protein glutathionylation. We observed that tumor cells mount a biphasic response after IR exposure which can be divided into early (0-6 h) and late (16-48 h) responses in terms of changes in cellular redox parameters. During early response, constitutively active GSH and Trx systems respond to restore cellular redox balance to pre-exposure levels and help in activation of redox-sensitive transcription factor Nrf-2. During late response, increase in the levels of antioxidants GSH and Trx rescue cells against IR-mediated damage. We observed that disruption of either glutathione or thioredoxin metabolism led to partial impairment of ability of cells to survive against IR-induced damage. But simultaneous disruption of both the pathways significantly increased radio sensitivity of Jurkat cells. This highlighted the importance of these two antioxidant pathways in regulating redox homeostasis under conditions of IR-induced oxidative stress.

The association between four SNPs of X-ray repair cross complementing protein 1 and the sensitivity to radiotherapy in patients with esophageal squamous cell carcinoma

Early stage diagnosis and therapeutic outcomes of esophageal squamous cell carcinoma remain poor. In order to evaluate the association between 4 single nucleotide polymorphisms (SNPs) of X-ray repair cross complementing protein 1 (XRCC1) and the sensitivity to radiotherapy in patients with esophageal squamous cell carcinoma (ESCC), the present study identified 4 SNPs of XRCC1 and evaluated the distribution of these genotypes among patients with ESCC. Venous blood samples from 175 patients with ESCC were collected and DNA was extracted. The 4 SNPs of the XRCC1 gene fragment were amplified using three primer pairs, which were sequenced. The mismatches were analyzed and identified using Basic Local Alignment Search Tool software. The sensitivity to radiotherapy was graded as effective and non-effective, according to the treatment results of the patients. The present study successfully amplified and sequenced 4 SNPs of XRCC1 in 112 out of the 175 patients with ESCC. The effective response rate of radiotherapy was 84.8% among the 112 patients. The effective response rate of patients with no mutation in the SNPs was 74.3%, and the rate increased to 89.6% in patients that had ≥1 mutation out of the 4 SNPs (χ²=4.389; P=0.036). For G28152A and G28152A mutations the effective response rate of patients was 91.2% (χ²=4.014; P=0.045) and 91.5% (χ²=4.451; P=0.035), respectively, which was significantly different compared to patients with no mutation (P=0.045 and P=0.035, respectively). The present results suggest that the 4 SNPs of XRCC1 are associated with the effective response rate of radiotherapy in patients with ESCC. The mutation of SNP G28152A was particularly important and may be a potential genomic predictor for radiotherapy sensitivity in patients with ESCC.

Tumor radio-sensitivity assessment by means of volume data and magnetic resonance indices measured on prostate tumor bearing rats

PURPOSE

Radiation therapy is one of the most common treatments in the fight against prostate cancer, since it is used to control the tumor (early stages), to slow its progression, and even to control pain (metastasis). Although many factors (e.g., tumor oxygenation) are known to influence treatment efficacy, radiotherapy doses and fractionation schedules are often prescribed according to the principle "one-fits-all," with little personalization. Therefore, the authors aim at predicting the outcome of radiation therapy a priori starting from morphologic and functional information to move a step forward in the treatment customization.

METHODS

The authors propose a two-step protocol to predict the effects of radiation therapy on individual basis. First, one macroscopic mathematical model of tumor evolution was trained on tumor volume progression, measured by caliper, of eighteen Dunning R3327-AT1 bearing rats. Nine rats inhaled 100% O2 during irradiation (oxy), while the others were allowed to breathe air. Second, a supervised learning of the weight and biases of two feedforward neural networks was performed to predict the radio-sensitivity (target) from the initial volume and oxygenation-related information (inputs) for each rat group (air and oxygen breathing). To this purpose, four MRI-based indices related to blood and tissue oxygenation were computed, namely, the variation of signal intensity ΔSI in interleaved blood oxygen level dependent and tissue oxygen level dependent (IBT) sequences as well as changes in longitudinal ΔR1 and transverse ΔR2(*) relaxation rates.

RESULTS

An inverse correlation of the radio-sensitivity parameter, assessed by the model, was found with respect the ΔR2(*) (-0.65) for the oxy group. A further subdivision according to positive and negative values of ΔR2(*) showed a larger average radio-sensitivity for the oxy rats with ΔR2(*)<0 and a significant difference in the two distributions (p < 0.05). Finally, a leave-one-out procedure yielded a radio-sensitivity error lower than 20% in both neural networks.

CONCLUSIONS

While preliminary, these specific results suggest that subjects affected by the same pathology can benefit differently from the same irradiation modalities and support the usefulness of IBT in discriminating between different responses.

A correlation analysis between HDAC1 over-expression and clinical features of laryngeal squamous cell carcinoma

CONCLUSION

HDAC1 may be a prognostic biomarker for LSCC malignant potency and a potent factor resulting in decreased sensitivity of LSCC in radiotherapy.

OBJECTIVE

The aim of this study was to evaluate the correlation between histone deacetylase 1 (HDAC1) over-expression and clinical features in laryngeal squamous cell carcinoma (LSCC).

METHODS

This study assessed the HDAC1 expressions in 90 formalin-fixed paraffin-embedded LSCC samples, 30 adjacent non-neoplastic tissues, and 30 laryngeal polyp tissues by immunohistochemistry (IHC). In addition, another 40 LSCC samples were collected that were divided into two groups after 3-month radiotherapy: the high radio-sensitive group (HRS) and low radio-sensitive group (LRS). Overall survival curves of all the LSCC patients were constructed by Kaplan-Meier method and long-rank test.

RESULTS

All ninety samples were positively immunostained for HDAC1. The expression of HDAC1 was up-regulated and significantly associated with T classification, lymph node metastases, tumor location and clinical stage. HDAC1 was mainly labeled in the epithelial cells of laryngeal polyp tissues and adjacent non-neoplastic tissues. In addition, the expression of HDAC1 was significantly higher in LRS than that in HRS. The positive rates for stage III-IV tumor were significantly higher than those for stage II. LSCC patients with HDAC1 over-expression and LRS presented a shorter 5-year overall survival rate.

Testicular orphan nuclear receptor 4 is associated with the radio-sensitivity of prostate cancer

BACKGROUND

It is well known that a significant number of prostate cancers (PCa) showed different extents of radio-resistance and the tumor may recur after treatment. Recent studies demonstrated that Testicular orphan nuclear receptor 4 (TR4) could play a critical role in anti-oxidative stress responses and might modulate the DNA damage repair. The objective of this study is to investigate the role of TR4 in the radiotherapy for PCa.

METHODS

The TR4 expression in tissue samples from PCa patients treated with brachytherapy was measured by immunohistochemistry (IHC). Cell survival test and colony formation assay were applied to test the radio-sensitivity of PCa cells with modulated TR4 gene expression upon irradiation.

RESULTS

PCa patients with biochemical recurrence (BCR) after brachytherapy tend to have higher TR4 expression (80%, n = 30) as compared to those without BCR (36.67%, n = 30). Survival analysis demonstrated a significant higher BCR occurrence in patients with high level of TR4 expression (HR = 3.474, 95%CI 1.678-7.192, P = 0.0008). Multivariate analysis showed that the TR4 staining score on IHC was the only significant variable for predicting the PCa patients' clinical outcomes after radiotherapy (OR = 9.919, 95% CI 2.516-39.101, P = 0.001). Using cell survival test and colony forming assay, we found that the addition of functional TR4 in PC3 cells lead to elevated radio-resistance. In contrast, knocking-down TR4 in LNCaP cells resulted in increased radio-sensitivity. The γH2AX foci kinetic analysis suggested that knocking down TR4 might delay the PCa cell's DNA damage repair which would enhance the radio-sensitivity.

CONCLUSION

TR4 could mediate the PCa cells' radio-sensitivity and might become a prognostic indicator for PCa patients received radiotherapy. This study provides a novel approach to manipulate radio-sensitivity of PCa cells, and may bring a promoted therapeutic outcome of radiotherapy to battle PCa in future.

The inter-individual variability outperforms the intra-individual variability of differentially expressed proteins prior and post irradiation in lymphoblastoid cell lines

CONTEXT

Radio-sensitivity in normal tissue is characterized by heterogeneity throughout the population and the absence of pre-diagnostic biomarkers.

OBJECTIVE

We conducted a proteomic approach to search for radiation characteristic protein regulation.

MATERIALS AND METHODS

Cell lines were 10 Gy irradiated and analysed by 2D-DIGE after 24 h. RESULTS were analysed intra- and inter-individually. The principal component analysis and hierarchical clustering was applied to all datasets.

RESULTS

Differences in intra-individual spot abundance prior and post irradiation exactly show the separation of sample classes in two groups: sham-irradiated and irradiated. The inter-individual datasets clustered according to the cell line. The intra-individual differences on protein level after gamma-irradiation are very low, compared with the inter-individual differences among cell lines derived from the same tissue.

CONCLUSION

The application of 2-D DIGE may offer a realistic chance for a better molecular characterization of radio-sensitivity and for the discovery of candidate biomarkers.

Correlation of Nuclear Morphometry and AgNOR Score with Radiation Response in Squamous Cell Cancers of the Head and Neck: A Preliminary Study

BACKGROUND

Prediction of radiation response before the completion of the radiotherapy schedule is challenging. Information about radiation response could help oncologist to choose the appropriate combination and sequence of therapies in the multidisciplinary management of cancer.

METHODS

The study involved 26 patients with squamous cell cancers of the head and neck region who received radiotherapy to a dose of 30 Gy in 10 fractions over a 2-week period as part of a split-course technique. Fine-needle aspiration cytology was performed on day 1 and day 5 of the schedule. The silver staining of the nuclear organiser region (AgNOR) and nuclear morphometric study were done on both days.

RESULTS

The median age of the patients was 44 years old. The primary tumours were distributed in the nasopharynx (n = 11), larynx and hypopharynx (n = 5), metastatic node (n = 4), and miscellaneous tumours were found in the head and neck sub sites (n = 6). The mean initial AgNOR score was 3.0, range 1.2-7.0. The median of nuclear and nucleolar diameters were 11.07 μm, range 7.70-16.6 μm, and 2.92 μm, range 1.09-11.66 μm, respectively. Patients with a pre-radiotherapy AgNOR score of greater than 2.5 were associated with disease progression and metastasis. However, the increased of nuclear diameter on day 5 compared with baseline predicted a good radiation response in patients (P = 0.016).

CONCLUSION

Intra-radiotherapy nuclear morphometry combined with baseline AgNOR score could be a simple and useful tool for the prediction of radiation response in head and neck cancers.