Long-term alterations of cytokines and growth factors expression in irradiated tissues and relation with histological severity scoring

Molecular mechanisms of poor osseointegration in irradiated bone: In vivo study in a rat tibia model

AIM

Radiotherapy is associated with cell depletion and loss of blood supply, which are linked to compromised bone healing. However, the molecular events underlying these effects at the tissue-implant interface have not been fully elucidated. This study aimed to determine the major molecular mediators associated with compromised osseointegration due to previous exposure to radiation.

MATERIALS AND METHODS

Titanium implants were placed in rat tibiae with or without pre-exposure to 20 Gy irradiation. Histomorphometric, biomechanical, quantitative polymerase chain reaction (qPCR) and enzyme-linked immunosorbent assay analyses were performed at 1 and 4 weeks after implantation.

RESULTS

The detrimental effects of irradiation were characterized by reduced bone-implant contact and removal torque. Furthermore, pre-exposure to radiation induced different molecular dysfunctions such as (i) increased expression of pro-inflammatory (Tnf) and osteoclastic (Ctsk) genes and decreased expression of the bone formation (Alpl) gene in implant-adherent cells; (ii) increased expression of bone formation (Alpl and Bglap) genes in peri-implant bone; and (iii) increased expression of pro-inflammatory (Tnf) and pro-fibrotic (Tgfb1) genes in peri-implant soft tissue. The serum levels of pro-inflammatory, bone formation and bone resorption proteins were greater in the irradiated rats.

CONCLUSIONS

Irradiation causes the dysregulation of multiple biological activities, among which perturbed inflammation seems to play a common role in hindering osseointegration.

Swallowing-related muscle inflammation and fibrosis induced by a single dose of radiation exposure in mice

BACKGROUND

Although radiotherapy is commonly used to treat head and neck cancer, it may lead to radiation-associated dysphagia (RAD). There are various causes of RAD, however, the mechanism has not yet been fully identified. Currently, the only effective treatment for RAD is rehabilitation. Additionally, there are few available animal models of RAD, necessitating the development of new models to establish and evaluate RAD treatments. We hypothesize that radiation-induced neck muscle fibrosis could be one of the causes of RAD due to impairment of laryngeal elevation. Therefore, in this study, we focused on the changes in inflammation and fibrosis of the strap muscles (Sternohyoid, Sternothyroid, and Thyrohyoid muscles) after a single-dose irradiation. This research aims to provide a reference animal model for future studies on RAD.

RESULTS

Compared to control mice, those treated with 72-Gy, but not 24-Gy, irradiation had significantly increased tumor necrosis factor-α (TNF-α) (p < 0.01) and α-smooth muscle actin (αSMA) (p < 0.05) expression at 10 days and significantly increased expression levels of motif chemokine ligand-2 (CCL2), α-SMA, tumor growth factor-β1 (TGF-β1), type1 collagen, and interleukin-1β (IL-1β) (p < 0.05) in the muscles at 1 month by real-time PCR analysis. The results of immunohistochemistry showed that the deposition of type 1 collagen gradually increased in extracellular space after radiation exposure, and the positive area was significantly increased at 3 months compared to non-irradiated control.

CONCLUSIONS

A single dose of 72-Gy irradiation induced significant inflammation and fibrosis in the strap muscles of mice at 1 month, with immunohistochemical changes becoming evident at 3 months. This cervical irradiation-induced fibrosis model holds potential for establishing an animal model for RAD in future studies.

LEVEL OF EVIDENCE

N/A.

Metformin and adipose-derived stem cell combination therapy alleviates radiation-induced skin fibrosis in mice

BACKGROUND

Radiation therapy often leads to late radiation-induced skin fibrosis (RISF), causing movement impairment and discomfort. We conducted a comprehensive study to assess the effectiveness of metformin and adipose-derived stem cells (ASCs), whether autologous or allogeneic, individually or in combination therapy, in mitigating RISF.

METHODS

Using a female C57BL/6J mouse model subjected to hind limb irradiation as a representative RISF model, we evaluated metformin, ASCs, or their combination in two contexts: prophylactic (started on day 1 post-irradiation) and therapeutic (initiated on day 14 post-irradiation, coinciding with fibrosis symptoms). We measured limb movement, examined skin histology, and analyzed gene expression to assess treatment efficacy.

RESULTS

Prophylactic metformin and ASCs, whether autologous or allogeneic, effectively prevented late fibrosis, with metformin showing promising results. However, combination therapy did not provide additional benefits when used prophylactically. Autologous ASCs, alone or with metformin, proved most effective against late-stage RISF. Prophylactic intervention outperformed late therapy for mitigating radiation skin damage. Co-culture studies revealed that ASCs and metformin downregulated inflammation and fibrotic gene expression in both mouse and human fibroblasts.

CONCLUSIONS

Our study suggests metformin's potential as a prophylactic measure to prevent RISF, and the combination of ASCs and metformin holds promise for late-stage RISF treatment. These findings have clinical implications for improving the quality of life for those affected by radiation-induced skin fibrosis.

Cytokine Levels in Saliva Are Associated with Salivary Gland Fibrosis and Hyposalivation in Mice after Fractionated Radiotherapy of the Head and Neck

Cytokines are mediators of inflammation that could lead to fibrosis. The aim was to monitor cytokine levels in saliva and serum after locally fractionated radiotherapy of the head and neck in mice and investigate associations with salivary gland fibrosis and hyposalivation. C57BL/6 mice were randomized to sham or X-ray irradiation of 66 Gy in 10 fractions over 5 days. Blood and saliva were collected on days -7, 5, 35, 80, and 105 following cytokine analysis. The harvested submandibular salivary gland was assessed for the presence of fibrosis. Decision tree regression analysis was used to investigate whether cytokine levels could predict late endpoints in terms of hyposalivation or fibrosis. Significant formation of fibrosis in gland tissue and reduced saliva production was found after irradiation. The pro-inflammatory cytokines IL-1α, TNF, TIMP1, G-CSF, KC, and MIP-1α showed increased levels in saliva in irradiated mice and a strong correlation with late endpoints. The decision tree analysis largely separated controls from irradiated animals, with IL-1α being the strongest predictor. Pro-inflammatory cytokines in saliva, but not in serum, were associated with late endpoints. This indicates that cytokine expression in saliva is a good biomarker for local salivary gland damage with IL-1α as the strongest single predictor.

Human adipose ECM alleviates radiation-induced skin fibrosis via endothelial cell-mediated M2 macrophage polarization

Radiation therapy can lead to late radiation-induced skin fibrosis (RISF), causing movement restriction, pain, and organ dysfunction. This study evaluated adipose-derived extracellular matrix (Ad-ECM) as a mitigator of RISF. Female C57BL/6J mice that were irradiated developed fibrosis, which was mitigated by a single local Ad-ECM injection, improving limb movement and reducing epithelium thickness and collagen deposition. Ad-ECM treatment resulted in decreased expression of pro-inflammatory and fibrotic genes, and upregulation of anti-inflammatory cytokines, promoting M2 macrophage polarization. Co-culture of irradiated human fibroblasts with Ad-ECM down-modulated fibrotic gene expression and enhanced bone marrow cell migration. Ad-ECM treatment also increased interleukin (IL)-4, IL-5, and IL-15 expression in endothelial cells, stimulating M2 macrophage polarization and alleviating RISF. Prophylactic use of Ad-ECM showed effectiveness in mitigation. This study suggests Ad-ECM's potential in treating chronic-stage fibrosis.

Evaluation of the Effects of Radiation Therapy on Muscle Contractibility and Skin Healing: An Experimental Study of the Cancer Treatment Implications

BACKGROUND

Radiotherapy can affect healthy cells, resulting in side effects. This study aimed to assess the impact of radiotherapy on soft tissue in surgical wounds in rats.

METHODS

The animals were divided into four groups: control (S) group without irradiation, immediate irradiation (S-IIr) group receiving irradiation right after surgery, late irradiation (S-LIr) group receiving irradiation four weeks after surgery, and early irradiation (Ir-S) group receiving irradiation before surgery. The irradiated groups underwent two fractional stages of 15 Gy. Muscle contractibility (EMG) was evaluated at two different time points, and after 2 and 7 weeks, the animals were euthanized for histological analysis of the muscles and skin.

RESULTS

There was no significant difference between the EMG1 and EMG2 values of the S and S-LIr groups, but both S-IIr and Ir-S groups exhibited a statistically significant difference. The S group demonstrated a larger diameter of muscle fiber compared to other groups, showing a significant difference. In terms of skin analysis, the S-IIr group had the least inflammatory infiltrate and the highest amount of red fibers, differing significantly from the other groups.

CONCLUSIONS

Regardless of the duration, radiotherapy was found to have effects on the surrounding soft tissues, as concluded by this study.

Results of Adjustable Trans-Obturator Male System in Patients with Prostate Cancer Treated with Prostatectomy and Radiotherapy: A Multicenter Study

(1) Background: Treatment of male stress incontinence in patients with prostate cancer treated with radical prostatectomy and adjuvant pelvic radiation is a therapeutic challenge. The efficacy and safety of the adjustable trans-obturator male system (ATOMS) in these patients is not well established, despite the general belief that outcomes are worse than in patients without radiation. (2) Methods: Retrospective multicenter study evaluating patients treated with silicone-covered scrotal port (SSP) ATOMS implant after radical prostatectomy and radiotherapy in nine different institutions between 2016 and 2022. The primary endpoint was dry patient rate, defined as pad-test ≤ 20 mL/day. The secondary endpoints were complication rate (defined using Clavien-Dindo classification), device removal and self-perceived satisfaction using the Patient Global Impression of Improvement (PGI-I) scale. Wilcoxon rank-sum test, Fisher's exact test and logistic regression were performed using stepwise method with a 0.15 entry and 0.1 stay criteria. (3) Results: 223 patients fulfilled the criteria for inclusion and 12 (5.4%) received salvage prostatectomy after radiation and 27 (12.1%) previous devices for stress incontinence. After ATOMS adjustment, 95 patients (42.6%) were dry and 36 (16.1%) had complications of any grade (grade I, n = 20; grade II, n = 11; grade III, n = 5) during the first 3 months postoperatively. At a mean of 36 ± 21 months follow-up, the device was explanted in 26 (11.7%) patients. Regarding self-perceived satisfaction with the implant, 105 of 125 patients (84%) considered themselves satisfied (PGI-I 1 to 3). In the univariate analysis, dryness was associated to younger age (p = 0.06), primary prostatectomy (p = 0.08), no previous incontinence surgery (p = 0.02), absence of overactive bladder symptoms (p = 0.04), absence of bladder neck stricture (p = 0.001), no need of surgical revision (p = 0.008) and lower baseline incontinence severity (p = 0.0003). Multivariate analysis identified absence of surgical revision (p = 0.018), absence of bladder neck stricture (p = 0.05), primary prostatectomy (p = 0.07) and lower baseline incontinence severity (p < 0.0001) were independent predictors of dryness. A logistic regression model was proposed and internally validated. (4) Conclusions: ATOMS is an efficacious and safe alternative to treat male incontinence after radical prostatectomy and adjuvant radiotherapy. Factors predictive of dryness are identified in this complex scenario to allow for better patient selection.

Predicting acute radiation dermatitis in breast cancer: a prospective cohort study

BACKGROUND

Acute radiation dermatitis (ARD) is one of the most common acute adverse reactions in breast cancer patients during and immediately after radiotherapy. As ARD affects patient quality of life, it is important to conduct individualized risk assessments of patients in order to identify those patients most at risk of developing severe ARD.

METHODS

The data of breast cancer patients who received radiotherapy were prospectively collected and analyzed. Serum ferritin, high-sensitivity C-reactive protein (hs-CRP) levels, and percentages of lymphocyte subsets were measured before radiotherapy. ARD was graded (0-6 grade), according to the Oncology Nursing Society Skin Toxicity Scale. Univariate and multivariate logistic regression analyses were used and the odds ratio (OR) and 95% confidence interval (CI) of each factor were calculated.

RESULTS

This study included 455 breast cancer patients. After radiotherapy, 59.6% and 17.8% of patients developed at least 3 (3+) grade and at least 4 (4+) grade ARD, respectively. Multivariate logistic regression analysis found that body mass index (OR: 1.11, 95% CI: 1.01-1.22), diabetes (OR: 2.70, 95% CI: 1.11-6.60), smoking (OR: 3.04, 95% CI: 1.15-8.02), higher ferritin (OR: 3.31, 95% CI: 1.78-6.17), higher hs-CRP (OR: 1.96, 95% CI: 1.02-3.77), and higher CD3 + T cells (OR: 2.99, 95% CI: 1.10-3.58) were independent risk factors for 4 + grade ARD. Based on these findings, a nomogram model of 4 + grade ARD was further established. The nomogram AUC was 0.80 (95% CI: 0.75-0.86), making it more discriminative than any single factor.

CONCLUSION

BMI, diabetes, smoking history, higher ferritin, higher hs-CRP, and higher CD3 + T cells prior to radiotherapy for breast cancer are all independent risk factors for 4 + grade ARD. The results can provide evidence for clinicians to screen out high-risk patients, take precautions and carefully follow up on these patients before and during radiotherapy.

Complications after Prostate Cancer Treatment: Pathophysiology and Repair of Post-Radiation Urethral Stricture Disease

Radiation therapy (RT) in the management of pelvic cancers remains a clinical challenge to urologists given the sequelae of urethral stricture disease secondary to fibrosis and vascular insults. The objective of this review is to understand the physiology of radiation-induced stricture disease and to educate urologists in clinical practice regarding future prospective options clinicians have to deal with this condition. The management of post-radiation urethral stricture consists of conservative, endoscopic, and primary reconstructive options. Endoscopic approaches remain an option, but with limited long-term success. Despite concerns with graft take, reconstructive options such as urethroplasties in this population with buccal grafts have shown long-term success rates ranging from 70 to 100%. Robotic reconstruction is augmenting previous options with faster recovery times. Radiation-induced stricture disease is challenging with multiple interventions available, but with successful outcomes demonstrated in various cohorts including urethroplasties with buccal grafts and robotic reconstruction.

Longitudinal Effects of Base of Tongue Concurrent Chemoradiation Therapy in a Pre-Clinical Model

BACKGROUND/OBJECTIVES

Base of tongue (BOT) dysfunction is common following oropharyngeal concurrent chemoradiation therapy (CCRT). We present a clinically relevant animal model quantifying the effects of CCRT on tongue strength and elasticity over time.

METHODS

Fifty-three male and 53 female Sprague-Dawley rats were randomized to control or experimental groups. Experimental animals received cisplatin, 5-fluorouracil, and 5 fractions of 7 Gy directed to the BOT. Controls received no intervention. At 2 weeks, 5 months, or 10 months after CCRT, animals underwent non-survival surgery to measure twitch and tetanic tongue strength, which were analyzed using multivariate linear mixed effects models. Tongue displacement, a surrogate for tongue elasticity, was also determined via stress-strain testing and analyzed via a multivariate linear mixed effects model.

RESULTS

Reporting the combined results of both sexes, the estimated experimental group mean peak twitch forces became more divergent over time compared to controls, being 8.3% lower than controls at 2 weeks post-CCRT, 15.7% lower at 5 months, and 31.6% lower at 10 months. Estimated experimental group mean peak tetanic forces followed a similar course and were 2.9% lower than controls at 2 weeks post CCRT, 20.7% lower at 5 months, and 27.0% lower at 10 months. Stress-strain testing did not find CCRT to have a significant effect on tongue displacement across experimental timepoints.

CONCLUSIONS

This study demonstrates an increasing difference in tongue strength over time between controls and animals exposed to CCRT. Tongue elasticity was not significantly affected by CCRT, suggesting that changes in strength may not be caused by fibrosis.

LEVEL OF EVIDENCE

NA Laryngoscope, 133:1455-1461, 2023.

Baicalein alleviates fibrosis and inflammation in systemic sclerosis by regulating B-cell abnormalities

BACKGROUND

Systemic sclerosis (SSc; also known as "scleroderma") is an autoimmune disorder characterized by extensive fibrosis, vascular changes, and immunologic dysregulation. Baicalein (phenolic flavonoid derived from Scutellaria baicalensis Georgi) has been used to treat the pathological processes of various fibrotic and inflammatory diseases. In this study, we investigated the effect of baicalein on the major pathologic characteristics of SSc: fibrosis, B-cell abnormalities, and inflammation.

METHODS

The effect of baicalein on collagen accumulation and expression of fibrogenic markers in human dermal fibroblasts were analyzed. SSc mice were produced by injecting bleomycin and treated with baicalein (25, 50, or 100 mg/kg). The antifibrotic features of baicalein and its mechanisms were investigated by histologic examination, hydroxyproline assay, enzyme-linked immunosorbent assay, western blotting and flow cytometry.

RESULTS

Baicalein (5-120 μM) significantly inhibited the accumulation of the extracellular matrix and fibroblast activation in transforming growth factor (TGF)-β1- and platelet derived growth factor (PDGF)-induced human dermal fibroblasts, as evidenced by abrogated deposition of total collagen, decreased secretion of soluble collagen, reduced collagen contraction capability and downregulation of various fibrogenesis molecules. In a bleomycin-induced model of dermal fibrosis in mice, baicalein (25-100 mg/kg) restored dermal architecture, ameliorated inflammatory infiltrates, and attenuated dermal thickness and collagen accumulation in a dose-dependent manner. According to flow cytometry, baicalein reduced the proportion of B cells (B220⁺ lymphocytes) and increased the proportion of memory B cells (B220⁺CD27⁺ lymphocytes) in the spleens of bleomycin-induced mice. Baicalein treatment potently attenuated serum levels of cytokines (interleukin (IL)-1β, IL-2, IL-4, IL-6, IL-17A, tumor necrosis factor-α), chemokines (monocyte chemoattractant protein-1, macrophage inflammatory protein-1 beta) and autoantibodies (anti-scleroderma 70 (Scl-70), anti-polymyositis-scleroderma (PM-Scl), anti-centromeres, anti-double stranded DNA (dsDNA). In addition, baicalein treatment can significantly inhibit the activation of TGF-β1 signaling in dermal fibroblasts and bleomycin-induce mice of SSc, evidenced by reducing the expression of TGF-β1 and IL-11, as well as inhibiting both small mother against decapentaplegic homolog 3 (SMAD3) and extracellular signal-related kinase (ERK) activation.

CONCLUSIONS

These findings suggest that baicalein has therapeutic potential against SSc, exerting modulating B-cell abnormalities, anti-inflammatory effects, and antifibrosis.

The miR-15b-Smurf2-HSP27 axis promotes pulmonary fibrosis

BACKGROUND

Heat shock protein 27 (HSP27) is overexpressed during pulmonary fibrosis (PF) and exacerbates PF; however, the upregulation of HSP27 during PF and the therapeutic strategy of HSP27 inhibition is not well elucidated.

METHODS

We have developed a mouse model simulating clinical stereotactic body radiotherapy (SBRT) with focal irradiation and validated the induction of RIPF. HSP25 (murine form of HSP27) transgenic (TG) and LLC1-derived orthotropic lung tumor models were also used. Lung tissues of patients with RIPF and idiopathic pulmonary fibrosis, and lung tissues from various fibrotic mouse models, as well as appropriated cell line systems were used. Public available gene expression datasets were used for therapeutic response rate analysis. A synthetic small molecule HSP27 inhibitor, J2 was also used.

RESULTS

HSP27 expression with its phosphorylated form (pHSP27) increased during PF. Decreased mRNA expression of SMAD-specific E3 ubiquitin-protein ligase 2 (Smurf2), which is involved in ubiquitin degradation of HSP27, was responsible for the increased expression of pHSP27. In addition, increased expression of miRNA15b was identified with decreased expression of Smurf2 mRNA in PF models. Inverse correlation between pHSP27 and Smurf2 was observed in the lung tissues of PF animals, an irradiated orthotropic lung cancer models, and PF tissues from patients. Moreover, a HSP27 inhibitor cross-linked with HSP27 protein to ameliorate PF, which was more effective when targeting the epithelial to mesenchymal transition (EMT) stage of PF.

CONCLUSIONS

Our findings identify upregulation mechanisms of HSP27 during PF and provide a therapeutic strategy for HSP27 inhibition for overcoming PF.

Skin Microbiome and Treatment-Related Skin Toxicities in Patients With Cancer: A Mini-Review

The human skin hosts millions of bacteria, fungi, archaea, and viruses. These skin microbes play a crucial role in human immunological and physiological functions, as well as the development of skin diseases, including cancer when the balance between skin commensals and pathogens is interrupted. Due to the linkages between inflammation processes and skin microbes, and viral links to skin cancer, new theories have supported the role a dysbiotic skin microbiome plays in the development of cancer and cancer treatment-related skin toxicities. This review focuses on the skin microbiome and its role in cancer treatment-related skin toxicities, particularly from chemotherapy, radiation therapy, and immunotherapy. The current literature found changes in the diversity and abundance of the skin microbiome during cancer treatments such as radiation therapy, including lower diversity of the skin microbiome, an increased Proteobacteria/Firmicutes ratio, and a higher abundance of pathogenic Staphylococcus aureus. These changes may be associated with the development and severity of treatment-related skin toxicities, such as acute radiation dermatitis, hand-foot syndrome in chemotherapy, and immunotherapy-induced rash. Several clinical guidelines have issued potential interventions (e.g., use of topical corticosteroids, phototherapy, and non-pharmaceutical skin care products) to prevent and treat skin toxicities. The effectiveness of these promising interventions in alleviating treatment-related skin toxicities should be further tested among cancer patients.

An Investigation of the Mechanisms of Radiation-Induced Muscle Injury in a Tree Shrew (Tupaia belangeri) Model

Background

Animal models suitable for investigating mechanisms behind radiation-induced muscle injury are lacking. We developed a tree shrew model of such injury and investigated pathological changes and mechanisms.

Methods

Animals were divided into control (n = 5), radiation-induced acute injury (n = 5), and radiation-induced chronic injury (n = 5) groups. Tensor veli palatini (TVP) muscles of acute injury and chronic injury groups were dissected under a microscope at 1 and 24 weeks after radiation therapy, respectively. TVP muscles were stained with HE and Masson to visualize pathological changes. ELISA was performed to measure oxidative injury. RT-qPCR and immunohistochemical staining was performed to measure expression levels of miR-206 and histone deacetylase 4 (HDAC4).

Results

Compared to the control group, acute injury group showed a significant decrease in miR-206 expression (.061 ± .38, P < .05) and a significant increase in HDAC4 expression (37.05 ± 20.68, P < .05). Chronic injury group showed a significant decrease in miR-206 expression (.23 ± .19, P < .05) and a significant increase in HDAC4 expression (9.66 ± 6.12, P < .05).

Discussion

A tree shrew model of radiation-induced muscle injury was established by exposing TVP muscle region to radiation of 20-Gy. Experimental results indicated that injury caused by radiation persisted despite gradual healing of the TVP muscle and miR-206 regulatory pathway plays a key role in regulating radiation-induced muscle injury.

Recurrent vesicourethral anastomotic stenosis following treatment for prostate cancer: an effective endoscopic treatment using bipolar plasma button and triamcinolone

PURPOSE

To evaluate the efficacy of deep bladder neck incision plus adjuvant Triamcinolone in the treatment of recurrent vesicourethral anastomotic stenosis following surgical treatment for prostate cancer.

MATERIALS AND METHODS

A retrospective review of patients undergoing bladder neck incision from 2013 to 2019 was conducted. Patients who had previously undergone surgical treatment for prostate cancer and had failed treatment for bladder neck contracture were included.

RESULTS

Twenty patients underwent deep bladder neck incision (BNI) with plasma button and adjuvant injection with a patency rate of 85%. Complete obliteration portended worst prognosis with 100% recurrence.

CONCLUSIONS

Deep BNI with triamcinolone is a minimally morbid alternative for treatment of refractory vesicourethral anastomotic contractures.

Feasibility study for inducing the skeletal muscle fibrosis via irradiation using two mouse strains

PURPOSE

Although the mechanism of onset and progression of radiation-induced fibrosis (RIF) has been studied, most studies to date have focused on pulmonary fibrosis. There are few studies on murine RIF in the skeletal muscle, and the pathogenic mechanism remains unclear. This pilot study aimed to evaluate the feasibility to create a murine model of RIF in the skeletal muscle and analyze strain differences in fibrosis sensitivity.

MATERIALS AND METHODS

Two mouse strains, C57BL/6 and C3H/He, were used. Their right hind limbs were irradiated at a dose of 25 Gy once a week for three fractions. Gastrocnemius muscles were collected at day 4, and weeks 2, 4, 8, 12, and 24 after the third irradiation and subjected to histopathological examination and immunoblotting.

RESULTS

In C57BL/6 mice, chronic inflammation and an increased expression of transforming growth factor-β (TGF-β) and fibronectin were observed 2 weeks after irradiation. A significant increase in fibrosis was detected after 8 weeks. However, in C3H/He mice, the expression of TGF-β and fibronectin increased 8 weeks after irradiation, and fibrosis significantly increased after 12 weeks. Moreover, the degrees of inflammation and fibrosis were more remarkable in C57BL/6 mice than in C3H/He mice.

CONCLUSION

The onset and degree of fibrosis may be associated with the expression of TGF-β and fibronectin, and inflammation, in a strain-specific manner. Therefore, a murine model of RIF in the skeletal muscle could be created using the indicated method, suggesting that the C57BL/6 strain is more sensitive to fibrosis in the skeletal muscle, as well as the lung, than the C3H/He strain. Radiation-induced fibrosis in the skeletal muscle could be detected in C57BL/6 and C3H/He mice, with C57BL/6 mice being more sensitive to fibrosis in the skeletal muscle than C3H/He mice.

SSC-ILD mouse model induced by osmotic minipump delivered bleomycin: effect of Nintedanib

Systemic sclerosis (SSc) is an autoimmune disease characterized by an excessive production and accumulation of collagen in the skin and internal organs often associated with interstitial lung disease (ILD). Its pathogenetic mechanisms are unknown and the lack of animal models mimicking the features of the human disease is creating a gap between the selection of anti-fibrotic drug candidates and effective therapies. In this work, we intended to pharmacologically validate a SSc-ILD model based on 1 week infusion of bleomycin (BLM) by osmotic minipumps in C57/BL6 mice, since it will serve as a tool for secondary drug screening. Nintedanib (NINT) has been used as a reference compound to investigate antifibrotic activity either for lung or skin fibrosis. Longitudinal Micro-CT analysis highlighted a significant slowdown in lung fibrosis progression after NINT treatment, which was confirmed by histology. However, no significant effect was observed on lung hydroxyproline content, inflammatory infiltrate and skin lipoatrophy. The modest pharmacological effect reported here could reflect the clinical outcome, highlighting the reliability of this model to better profile potential clinical drug candidates. The integrative approach presented herein, which combines longitudinal assessments with endpoint analyses, could be harnessed in drug discovery to generate more reliable, reproducible and robust readouts.

Fat Grafting in Radiation-Induced Soft-Tissue Injury: A Narrative Review of the Clinical Evidence and Implications for Future Studies

SUMMARY

Radiation-induced changes in skin and soft tissue result in significant cosmetic and functional impairment with subsequent decrease in quality of life. Fat grafting has emerged as a therapy for radiation-induced soft-tissue injury, and this narrative review aims to evaluate the current clinical evidence regarding its efficacy. A review was conducted to examine the current clinical evidence of fat grafting as a therapy for radiation-induced injury to the skin and soft tissue and to outline the clinical outcomes that can be used to more consistently quantify chronic radiation-induced injury in future clinical studies. The current clinical evidence regarding the efficacy of fat grafting to treat radiation-induced injury of the skin and soft tissue suggests that fat grafting increases skin softness and pliability, induces volume restoration, improves hair growth in areas of alopecia, reduces pain, and improves cosmetic and functional outcomes. However, literature in this field is far from robust and mired by the retrospective nature of the studies, lack of adequate controls, and inherent limitations of small case series and cohorts. A series of actions have been identified to strengthen future clinical data, including the need for physical examination using a validated scale, appropriate imaging, skin biomechanics and microcirculation testing, and histologic analysis. In conclusion, radiation-induced soft-tissue injury is a significant health burden that can lead to severe functional and aesthetic sequelae. Although still in a preliminary research phase, there is promising clinical evidence demonstrating the benefits of fat grafting to treat chronic changes after radiation therapy. Future clinical studies will require larger cohorts, adequate controls, and consistent use of objective measurements.

Estimating the risks and benefits before salvage surgery for recurrent head and neck squamous cell carcinoma

INTRODUCTION

The risks associated with salvage surgery of head and neck squamous cell carcinoma (SCC) in a previously irradiated field needs to be balanced against the expected survival benefits. We want to identify preoperative predictive factors for overall and disease-specific survival (OS/DSS) and for the development of serious (Clavien-Dindo, CD≥III) complications following salvage surgery for radiorecurrent SCC to help surgeons, patients, and caregivers in the decision-making process in this setting.

MATERIALS AND METHODS

The records of 234 patients presenting to the Lorraine Cancer Institute with locoregional radiorecurrent SCC were reviewed. The primary endpoint was OS, secondary endpoints were DSS, OS without tracheostomy/gastrostomy, and the risk of CD≥III complications. Multivariate analyses were carried out to explore preoperative factors associated with survival and the risk of postoperative complications.

RESULTS

With a median follow-up time of 19 months, 5-year OS since the first salvage surgery was 28.3%, 5-year DSS was 38.9%. 2- and 5-year functional OS were 45.6% and 27.2%. rcT-rcN, and WUNHCI ≥4 were both independent significant preoperative predictors of OS and DSS. 30-days postoperative complications occurred in 44.4% of patients (28 CD I, 24 CD II, 34 CD III, 11 CD IV, 7 CD V). A salvage procedure involving T+N plus the presence of a WUHNCI ≥4 was the only independent predictor of CD≥III complications.

CONCLUSION

When discussing with the patients and the caregivers salvage surgery for recurrent head and neck SCC, a careful evaluation of the preoperative comorbidities by the WUHNCI tool can reliably predict the expected risks and benefits from the procedure.

Development of hematopoietic syndrome mice model for localized radiation exposure

Current models to study the hematopoietic syndrome largely rely on the uniform whole-body exposures. However, in the radio-nuclear accidents or terrorist events, exposure can be non-uniform. The data available on the non-uniform exposures is limited. Thus, we have developed a mice model for studying the hematopoietic syndrome in the non-uniform or partial body exposure scenarios using the localized cobalt⁶⁰ gamma radiation exposure. Femur region of Strain 'A' male mice was exposed to doses ranging from 7 to 20 Gy. The 30 day survival assay showed 19 Gy as LD₁₀₀ and 17 Gy as LD_50. We measured an array of cytokines and important stem cell markers such as IFN-γ, IL-3, IL-6, GM-CSF, TNF-α, G-CSF, IL-1α, IL-1β, CD 34 and Sca 1. We found significant changes in IL-6, GM-CSF, TNF-α, G-CSF, and IL-1β levels compared to untreated groups and amplified levels of CD 34 and Sca 1 positive population in the irradiated mice compared to the untreated controls. Overall, we have developed a mouse model of the hematopoietic acute radiation syndrome that might be useful for understanding of the non-uniform body exposure scenarios. This may also be helpful in the screening of drugs intended for individuals suffering from radiation induced hematopoietic syndrome.

Radiation-induced skin injury: pathogenesis, treatment, and management

Radiation-induced skin injury (RSI) refers to a frequently occurring complication of radiation therapy. Nearly 90% of patients having received radiation therapy underwent moderate-to-severe skin reactions, severely reducing patients' quality of life and adversely affecting their disease treatment. No gold standard has been formulated for RSIs. In the present study, the mechanism of RSI and topical medications was discussed. Besides, this study can be referenced for clinicians to treat RSIs to guide subsequent clinical medicine.

Cytokine and Growth Factor Response in a Rat Model of Radiation Induced Injury to the Submental Muscles

Submental muscles (i.e., mylohyoid and geniohyoid) play a vital role during swallowing, protecting the airway from ingested material. To design therapies to reduce the functional deficits associated with radiation treatment relies in part on our understanding of the changes in the cytokine and growth factor response that can impact muscle function. The purpose of this study is to quantify changes in the inflammatory, pro-fibrotic, and pro-angiogenic factors following 48 Gy of fractionated radiation to the mylohyoid muscle. We hypothesized that (1) irradiation will provoke increases in TGF-1β and MMP-2 mRNA in the mylohyoid muscle; and (2) muscles surrounding the target location (i.e., geniohyoid and digastric muscles) will exhibit similar alterations in their gene expression profiles. Rats were exposed to 6 fractions of 8 Gy using a 6 MeV electron beam on a clinical linear accelerator. The highest dose curve was focused at the mylohyoid muscle. After 2- and 4-weeks post-radiation, the mylohyoid, geniohyoid, and digastric muscles were harvested. Expression of TNF-α, IFNγ, IL-1β, IL-6, TGF-1β, VEGF, MMP-2, and MMP-9 mRNA was analyzed via PCR and/or RT-PCR. TGF-1β, MMP-2, and IL-6 expression was upregulated in the irradiated mylohyoid compared to non-irradiated controls. No notable changes in TNF-α, IFNγ, and IL-1β mRNA expression were observed in irradiated muscles. Differing expression profiles were found in the surrounding muscles post-radiation. Results demonstrated that irradiation provokes molecular signals involved in the regulation of wound healing, which could lead to fibrosis or atrophy in the swallowing muscle after radiation.

ICG-induced NIR fluorescence mapping in patients with head & neck tumors after the previous radiotherapy

BACKGROUND

The distinction between tumor and healthy tissues is complicated in the areas previously subjected to radiation therapy (RT). This is related to the fact that tissues can undergo delayed and irreversible deterioration such as inflammation, vascular alteration and fibrosis. The trials related to the fluorescence -guided surgery (FSG) in Head and Neck Squamous Cell Carcinoma (HNSCC) patients, previously subjected to RT, have not yet been reported. The present study addresses for the first time the possibilities of tumor near-infrared (NIR) imaging using Indocynaine Green (ICG) in irradiated areas.

METHODS

Four patients with histologically confirmed HNSCC were included in this study. All included patients were previously treated with RT with at least 50 Gy. RT-radiation fields from original treatment fully encompassed the second tumor or recurrence. ICG was injected via cephalic vein 45 min before the images were captured using a NIR camera system Artemis. The images were also captured before ICG injection serving as background signal. The fluorescence intensity measurements were carried out using specially designed software.

RESULTS

ICG fluorescence clearly demonstrated a significant difference in fluorescence intensity between healthy and tumor tissues in 2 of 4 patients. Histology post-resection analysis confirmed a complete tumor resection with safe surgical margins. No difference between tumor and surrounding healthy tissue was detected in patients with an epidermoid carcinoma developed from sclerohypertrophic lichen.

CONCLUSIONS

In our pilot study, we clearly established the feasibility of using NIR FGS with ICG to delineate tumor and healthy tissues in irradiated areas in infiltrating lichen-free tumors.

Ultra-Low-Dose Bevacizumab For Cerebral Radiation Necrosis: A Prospective Phase II Clinical Study

Objective

To investigate the treatment efficacy of ultra-low-dose bevacizumab for cerebral radiation necrosis.

Methods

Patients with cerebral radiation necrosis after stereotactic radiotherapy (SRT) confirmed by imaging were included. Bevacizumab (1 mg/kg, once every three weeks, for at least three continuous treatments) was administered. The primary endpoints included change in cerebral necrosis symptoms, volume of intracranial edema, and changes in MRI signals. The secondary endpoints were adverse reactions of bevacizumab treatment.

Results

In total, 21 patients were included in this study, all of whom received SRT between December 2016 and February 2019, developed cerebral radiation necrosis, and were treated with bevacizumab. Twenty patients were symptomatic from radiation necrosis, and the symptoms were alleviated in 18 patients (90%). Twenty patients had intracranial edema, and the grade of edema index (EI) was improved in 19 patients (95%). The intensity of the intracranial-enhanced MRI signals was significantly reduced in 20 patients (95.24%). The adverse reactions of bevacizumab treatment were mild, and no adverse reactions more severe than grade 2 were found.

Conclusion

The preliminary results showed that ultra-low-dose bevacizumab had high efficacy for treating cerebral radiation necrosis, and could be a valid alternative to the standard-dose bevacizumab.

Clinical registry

Chinese clinical trial registry (ChiCTR-IOD-16009803).

Short-term influences of radiation on musculofascial healing in a laparotomy rat model

Preoperative radiation is associated with an increased risk of wound complications. However, the influences of radiation on musculofascial wound healing remains unclear. The purpose of the study was to investigate the short-term effects of preoperative local radiation on the musculofascial healing of laparotomy incisions in a rat model. Eighteen Fischer 344 rats received radiation doses of 0, 10, or 20 Gy to the abdominal wall and underwent laparotomy 4 weeks later. Two weeks after laparotomy, samples of irradiated muscle were harvested for mechanical tests, histological (Hematoxylin & Eosin, and Masson's Trichrome) and immunohistochemical analyses using KI67, CD31, TGF-β, and MYOD1 antibodies. The elastic modulus (EM), maximum strain (MS), and ultimate tensile strength (UTS) in the 20-Gy group were significantly weaker than those in the 0-Gy group. The EM and UTS in the 20-Gy group were significantly lower than those in the 10-Gy group. The UTS and MS in the 10-Gy group were significantly lower than those in the 0-Gy group. The mean number of inflammatory cells per mm² in the 20-Gy group was significantly larger than those in the 10- and 0-Gy groups. The mean numbers of CD31-, KI67-, and MYOD1-positive cells, the optical density of TGF-β, and the microvessel density in the 20-Gy group were significantly smaller than those in the 10- and 0-Gy groups. These results indicated that radiation delays musculofascial healing and decreases mechanical strength of the laparotomy incision by creating a chronic inflammatory environment, inhibiting cell proliferation, angiogenesis, granulation maturation, collagen deposition, and muscular regeneration in a dose-dependent manner. The impaired biomechanical, histological and molecular properties may be associated with the higher risk of wound complications in patients who undergo radiotherapy prior to laparotomy.

The Involvement of SDF-1α/CXCR4 Axis in Radiation-Induced Acute Injury and Fibrosis of Skin

Radiation-induced acute skin injury and consequent fibrosis are common complications of cancer radiotherapy and radiation accidents. Stromal cell-derived factor-1α (SDF-1α) and its receptor, CXC chemokine receptor 4 (CXCR4) have been shown to be involved in multiple cellular events. However, the role of SDF-1α/CXCR4 axis in radiation-induced acute injury and fibrosis of skin has not been reported. In this study, we found that the expression of SDF-1α and CXCR4 was significantly increased in irradiated skin tissues of humans, monkeys and rats, compared to their nonirradiated counterparts. Mice with keratinocyte-specific ablation of CXCR4 showed less severe skin damage than wild-type mice after receiving a 35 Gy dose of radiation. Consistently, subcutaneous injection of AMD3100, an FDA approved SDF-1α/CXCR4 inhibitor, attenuated skin injury and fibrosis induced by exposure to radiation in a rat model. Mechanically, the SDF-1α/CXCR4 axis promotes pro-fibrotic TGF-b/Smad signaling through the PI3K-MAPK signaling cascade in human keratinocyte HaCaT cells and skin fibroblast WS1 cells. AMD3100 inhibited Smad2 nuclear translocation and transcriptional activity of Smad2/3 induced by radiation, which suppressed the pro-fibrotic TGF-b/Smad signaling pathway activated by exposure. Taken together, these findings demonstrate the involvement of SDF-1α/CXCR4 axis in radiation-induced acute injury and fibrosis of skin, and indicate that AMD3100 would be an effective countermeasure against these diseases.

Systemic and local effects of radiotherapy: an experimental study on implants placed in rats

OBJECTIVES

Evaluate the modulating effect of ionizing radiation, blood cytokine levels, and bone remodeling of the interface around the implant to understand the radiation mechanisms which can impair the implants receptor site.

MATERIAL AND METHODS

Sixty rats were submitted to grade V titanium implants in the femurs and were divided into the following groups: no-irradiation (N-Ir): control group with implant only; early-irradiation (E-Ir): implant + irradiation after 24 h; late-irradiation (L-Ir): implant + irradiation after 4 weeks; and previous-irradiation (P-Ir): irradiation + implant after 4 weeks. The animals in the E-Ir, L-Ir, and P-Ir groups were irradiated in two fractional stages of 15 Gy. At 3 days, 2 weeks, and 7 weeks after the final procedure, five animals were randomly euthanized per group. Serum levels of TNF-ɑ, IL-1β, TGF-β, IL-6, M-CSF, and IL-10 were measured from blood collected prior to euthanasia using the ELISA test. The pieces containing the implants were subjected to immunohistochemical labeling using the tartrate acid resistant to phosphatase, osteocalcin, and caspase-3 markers and mCT. The ANOVA test was used for statistical analysis, and the Tukey multiple comparison test (p < 0.05) was applied.

RESULTS

The results indicated that ionizing radiation modifies the production of pro- and anti-inflammatory serum cytokines, the expression of proteins involved in bone remodeling and cellular apoptosis, as well as changes in bone formation.

CONCLUSIONS

The results suggests that a longer period between radiotherapy and implant placement surgery when irradiation occurs prior to implant installation would allow the recovery and renewal of bone cells and avoid future failures in osseointegration.

CLINICAL RELEVANCE

The search for modifications caused by ionizing irradiation in bone tissue can indicate the ideal period for implant placement without affecting the osseointegration process.

Adipose-Derived Stem Cell Therapy Ameliorates Ionizing Irradiation Fibrosis via Hepatocyte Growth Factor-Mediated Transforming Growth Factor-β Downregulation and Recruitment of Bone Marrow Cells

Radiation therapy to anatomic regions, including the head and neck, chest wall, and extremities, can produce radiation-induced fibrosis (RIF). To elucidate the cellular and molecular mechanism(s) involved in RIF, female C57BL/6J mice were irradiated to the right flank to 35 Gy in single fraction using 6 Mv electrons. Radiation fibrosis was detected by day 14, was increased by day 28, and confirmed by Masson's trichrome histological staining for collagen. Biopsied tissue at day 14 showed an increase in expression of fibrosis-related genes including transforming growth factor-β (TGF-β) and collagens 1-6. A single adipose-derived stem cell (ASC) injection on day 28 at the irradiated site decreased by day 40: epithelial thickness, collagen deposition, and significantly improved limb excursion compared with irradiated controls. Noncontact transwell coculture of ASCs above a monolayer of irradiated human foreskin fibroblasts downregulated fibrosis-related genes TGF-β, connective tissue growth factor, interleukin-1, NF-kB, tumor necrosis factor, and collagens 1-6. Hepatocyte growth factor (HGF) secreted by ASCs was identified as a novel mechanism by which ASCs exert antifibrotic effects by downregulating fibrotic gene expression in irradiated cells and recruiting bone marrow cells to the irradiated site. In conclusion, these data indicate a mechanistic role of HGF secreted by ASCs in reducing RIF. Stem Cells 2019;37:791-802.

A Rat Model of Radiation Vasculitis for the Study of Mesenchymal Stem Cell-Based Therapy

Radiation vasculitis is one of the most common detrimental effects of radiotherapy for malignant tumors. This is developed at the vasculature of adjacent organs. Animal experiments have showed that transplantation of mesenchymal stem cells (MSCs) restores vascular function after irradiation. But the population of MSCs being engrafted into irradiated vessels is too low in the conventional models to make assessment of therapeutic effect difficult. This is presumably because circulating MSCs are dispersed in adjacent tissues being irradiated simultaneously. Based on the assumption, a rat model, namely, RT (radiation) plus TX (transplantation), was established to promote MSC homing by sequestering irradiated vessels. In this model, a 1.5 cm long segment of rat abdominal aorta was irradiated by 160kV X-ray at a single dose of 35Gy before being procured and grafted to the healthy counterpart. F344 inbred rats served as both donors and recipients to exclude the possibility of immune rejection. A lead shield was used to confine X-ray delivery to a 3 cm×3 cm square-shaped field covering central abdominal region. The abdominal viscera especially small bowel and colon were protected from irradiation by being pushed off the central abdominal cavity. Typical radiation-induced vasculopathy was present on the 90^th day after irradiation. The recruitment of intravenously injected MSCs to irradiated aorta was significantly improved by using the RT-plus-TX model as compared to the model with irradiation only. Generally, the RT-plus-Tx model promotes MSC recruitment to irradiated aorta by separating irradiated vascular segment from adjacent tissue. Thus, the model is preferred in the study of MSC-based therapy for radiation vasculitis when the evaluation of MSC homing is demanding.

Radiation-induced muscle fibrosis rat model: establishment and valuation

Background

Lack of animal model of radiation induced muscle fibrosis, this study aimed to establish such a model by using 90 Gy single dose irradiation to mimic clinical relevance and also to explore the potential post-irradiation regenerative mechanism.

Methods

SD rats were randomly divided into dose investigation groups and time gradient groups. Group1–6 were irradiated with a single dose of 65Gy, 70Gy, 75Gy, 80Gy, 85Gy and 90Gy respectively, and the degree of rectus femoris fibrosis in the irradiated area was detected at 4 weeks after irradiation. Group 7–9 were irradiated with a single dose of 90Gy, and the results were detected 1, 2, 4, and 8 weeks after irradiation. Then the general condition of rats was recorded. Masson staining was used to detect muscle fibrosis. The ultrastructure of muscles was observed by electron microscope, and the expression changes of satellite cell proliferation and differentiation related genes were detected by quantitative real-time-PCR.

Results

A single dose of 90Gy irradiation could cause muscle fibrosis in rats. As time goes on, the severity of muscle fibrosis and the expression of TGF- β1 increased. Significant swelling of mitochondria, myofilament disarrangement and dissolution, obvious endothelial cell swelling, increased vascular permeability, decrease of blood cell, deposition of fibrosis tissue around the vessel could be found compared with the control group. At around the 4th week, the expressions of Pax7, Myf5, MyoD, MyoG, Mrf4 increased.

Conclusion

Irradiation of 90Gy can successfully establish the rat model of radiation-induced muscle fibrosis. This model demonstrated that regenerative process was initiated by the irradiation only at an early stage, which can serve a suitable model for investigating regenerative therapy for post-radiation muscle fibrosis.

Association Between Inflammatory Biomarker C-Reactive Protein and Radiotherapy-Induced Early Adverse Skin Reactions in a Multiracial/Ethnic Breast Cancer Population

Purpose This study examined an inflammatory biomarker, high-sensitivity C-reactive protein (hsCRP), in radiotherapy (RT)-induced early adverse skin reactions or toxicities in breast cancer. Patients and Methods Between 2011 and 2013, 1,000 patients with breast cancer who underwent RT were evaluated prospectively for skin toxicities through the National Cancer Institute-funded Wake Forest University Community Clinical Oncology Program Research Base. Pre- and post-RT plasma hsCRP levels and Oncology Nursing Society skin toxicity criteria (0 to 6) were used to assess RT-induced skin toxicities. Multivariable logistic regression analyses were applied to ascertain the associations between hsCRP and RT-induced skin toxicities after adjusting for potential confounders. Results The study comprised 623 white, 280 African American, 64 Asian/Pacific Islander, and 33 other race patients; 24% of the patients were Hispanic, and 47% were obese. Approximately 42% and 15% of patients developed RT-induced grade 3+ and 4+ skin toxicities, respectively. The hsCRP levels differed significantly by race and body mass index but not by ethnicity. In multivariable analysis, grade 4+ skin toxicity was significantly associated with obesity (odds ratio [OR], 2.17; 95% CI, 1.41 to 3.34], post-RT hsCRP ≥ 4.11 mg/L (OR, 1.61; 95% CI, 1.07 to 2.44), and both factors combined (OR, 3.65; 95% CI, 2.18 to 6.14). Above-median post-RT hsCRP (OR, 1.93; 95% CI, 1.03 to 3.63), and change in hsCRP (OR, 2.80; 95% CI, 1.42 to 5.54) were significantly associated with grade 4+ skin toxicity in nonobese patients. Conclusion This large prospective study is the first to our knowledge of hsCRP as an inflammatory biomarker in RT-induced skin toxicities in breast cancer. We demonstrate that nonobese patients with elevated RT-related change in hsCRP levels have a significantly increased risk of grade 4+ skin toxicity. The outcomes may help to predict RT responses and guide decision making.

Toll-like receptor 4 and its associated proteins as prognostic factors for HCC treated by post-radiotherapy surgery

Locally advanced hepatocellular carcinoma (HCC) treated by radiotherapy (RT) may be suited for further treatment with surgery. As a critical mediator of the post-RT immune response, Toll-like receptor 4 (TLR4) and its associated proteins may serve as prognostic factors for patients with HCC treated by post-RT surgery. In the present study, a total of 20 patients with HCC treated by post-RT surgery were enrolled. Resected tumor and peritumoral liver tissues were used to construct tissue microarrays that were assessed with immunohistochemical staining for the expression levels of TLR4, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and vascular endothelial growth factor receptor 2 (VEGFR2). The overall (OS) and disease-free (DFS) survival outcomes for each patient were assessed, and the severity of radiation-induced liver diseases (RILDs) was detected. The patients with low TLR4 or TRAIL expression exhibited significantly better OS times than those with high TLR4 (P=0.003) or TRAIL (P=0.007) expression, whereas the median DFS times for patients with low VEGFR2 or TRAIL were significantly longer than those with high VEGFR2 (P=0.003) or TRAIL (P=0.008) expression. No significant differences in OS or DFS times were identified according to the expression of TLR4, VEGFR2 or TRAIL in peritumoral liver tissue, although more severe RILDs were identified in patients with the high expression of these factors in the peritumoral liver tissue post-RT (P<0.05). Therefore, the expression levels of TLR4 and its associated proteins in HCC tumors may be suitable as prognostic factors for patients with HCC treated by post-RT surgery. The inhibition of TLR4, VEGFR2 and TRAIL expression in HCC and non-tumor liver tissue may lessen the severity of RILDs and improve survival outcomes in the future.

The effects of concurrent chemoradiation therapy to the base of tongue in a preclinical model

OBJECTIVES/HYPOTHESIS

To develop a clinically relevant model of oropharyngeal concurrent chemoradiation therapy (CCRT) in order to quantify the effects of CCRT on tongue function and structure. CCRT for advanced oropharyngeal cancer commonly leads to tongue base dysfunction and dysphagia. However, no preclinical models currently exist to study the pathophysiology of CCRT-related morbidity, thereby inhibiting the development of targeted therapeutics.

STUDY DESIGN

Animal model.

METHODS

Twenty-one male Sprague-Dawley rats were randomized into three groups: 2 week (2W), 5 month (5M), and control (C). The 2W and 5M animals received cisplatin, 5-fluorouracil, and five fractions of 7 Gy to the tongue base; the C animals received no intervention. In vivo tongue strength and displacement, as well as hyoglossus muscle collagen content, were assessed. Analyses were conducted 2 weeks or 5 months following completion of CCRT in the 2W and 5M groups, respectively.

RESULTS

Peak tetanic and twitch tongue forces were significantly reduced in both 2W and 5M animals compared to controls (tetanic: P = .0041, P = .0089, respectively; twitch: P = .0201, P = .0020, respectively). Twitch half-decay time was prolonged in 2W animals compared to controls (P = .0247). Tongue displacement was significantly reduced across all testing parameters in 5M animals compared to both the C and 2W groups. No differences in collagen content were observed between experimental groups.

CONCLUSIONS

The current study is the first to describe a preclinical model of CCRT to the head and neck with an emphasis on clinical relevance. Tongue strength decreased at 2 weeks and 5 months post-CCRT. Tongue displacement increased only at 5 months post-CCRT. Fibrosis was not detected, implicating alternative causative factors for these findings.

LEVEL OF EVIDENCE

NA Laryngoscope, 1783-1790, 2018.

Stimulation of triple negative breast cancer cell migration and metastases formation is prevented by chloroquine in a pre-irradiated mouse model

Background

Some triple negative breast cancer (TNBC) patients are at higher risk of recurrence in the first three years after treatment. This rapid relapse has been suggested to be associated with inflammatory mediators induced by radiation in healthy tissues that stimulate cancer cell migration and metastasis formation. In this study, the ability of chloroquine (CQ) to inhibit radiation-stimulated development of metastasis was assessed.

Methods

The capacity of CQ to prevent radiation-enhancement of cancer cell invasion was assessed in vitro with the TNBC cell lines D2A1, 4T1 and MDA-MB-231 and the non-TNBC cell lines MC7-L1, and MCF-7. In Balb/c mice, a single mammary gland was irradiated with four daily doses of 6 Gy. After the last irradiation, irradiated and control mammary glands were implanted with D2A1 cells. Mice were treated with CQ (vehicle, 40 or 60 mg/kg) 3 h before each irradiation and then every 72 h for 3 weeks. Migration of D2A1 cells in the mammary gland, the number of circulating tumor cells and lung metastasis were quantified, and also the expression of some inflammatory mediators.

Results

Irradiated fibroblasts have increased the invasiveness of the TNBC cell lines only, a stimulation that was prevented by CQ. On the other hand, invasiveness of the non-TNBC cell lines, which was not enhanced by irradiated fibroblasts, was also not significantly modified by CQ. In Balb/c mice, treatment with CQ prevented the stimulation of D2A1 TNBC cell migration in the pre-irradiated mammary gland, and reduced the number of circulating tumor cells and lung metastases. This protective effect of CQ was associated with a reduced expression of the inflammatory mediators interleukin-1β, interleukin-6, and cyclooxygenase-2, while the levels of matrix metalloproteinases-2 and −9 were not modified. CQ also promoted a blocking of autophagy.

Conclusion

CQ prevented radiation-enhancement of TNBC cell invasion and reduced the number of lung metastases in a mouse model.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2393-z) contains supplementary material, which is available to authorized users.

Post-Irradiated Human Submandibular Glands Display High Collagen Deposition, Disorganized Cell Junctions, and an Increased Number of Adipocytes

Salivary glands are vital for maintaining oral health. Head and neck radiation therapy is one of the most common causes of salivary gland hypofunction. Little is known about the structural changes that occur in salivary glands after radiation therapy. The aim of this study is to understand the structural changes that occur in post-irradiated human (submandibular gland [SMG]) as compared with untreated ones. We determined changes in epithelial polarity, presence of collagen deposition, and alteration in adipose tissue. We used formalin-fixed paraffin-embedded human SMG from two female subjects exposed to head and neck irradiation. We utilized hematoxylin and eosin staining and Masson's Trichrome staining. The immunostained tissue sections were examined using confocal microscopy. The number and size of adipocytes per tissue section were calculated using ImageJ, Prism, and SPSS software. Post-irradiated human SMG displayed high collagen deposition, disorganized cell junctions, and an increased number of adipocytes as compared with non-irradiated controls. These findings are important to improve our understanding of the individual risk and variation in radiation-related salivary gland dysfunction.

A study on the evaluation method and recent clinical efficacy of bevacizumab on the treatment of radiation cerebral necrosis

In order to investigate the efficacy of bevacizumab on the treatment of radiation cerebral necrosis, patients who were diagnosed with radiation cerebral necrosis by imaging after stereotactic radiotherapy were collected. Bevacizumab was applied at a dose of 5 mg/kg once every three weeks at least three times. The changes in cerebral necrosis symptoms before and after treatment, the cerebral edema volume, the cerebral necrosis volume, and the changes in magnetic resonance imaging (MRI) strengthening phase signals of cerebral necrosis were used as the first observation point. The side effects of bevacizumab were used as the second observation point. Total of 14 radiation cerebral necrosis patients were treated with bevacizumab between June 2011 and February 2013 were collected. There were 12 symptomatic patients, of whom 10 patients (83.3%) had reduced symptoms. The edema index grades of nine patients (64.29%) improved. The cerebral necrosis volumes of 13 patients (92.86%) decreased. The T1 phase signal strengths of the intracranial enhanced MRIs of 12 patients (85.71%) significantly decreased. The clinical side effects of bevacizumab were mild. In conclusion, Preliminary results showed that treatment of radiation cerebral necrosis using bevacizumab was safe and effective. This treatment measure is worthy of further study.

Obstructive sleep apnea and fatigue in head and neck cancer patients

There is a systematic relationship between fatigue, sleep, and decreased quality of life in cancer patients, with notably poor sleep quality among many head and neck cancer patients during and after treatment. An often overlooked cause of sleep disturbance in this patient population is obstructive sleep apnea (OSA). This review explores the current literature on the prevalence and clinical correlates of OSA, management outcomes, and data on cytokine-mediated fatigue in OSA. OSA appears to be prevalent in head and neck cancer patients, both at baseline and after treatment, especially with multimodality therapy including radiation therapy. Predictors of developing OSA include larger tumor size and hypopharynx or larynx primary site. There is evidence that the level of fatigue seen in these patients is not necessarily correlated with the severity of their OSA. Current research highlights the role of proinflammatory cytokines, which can also be synergistically activated by radiation therapy, as mediators of fatigue. Primary management of OSA consists of continuous positive airway pressure. Although continuous positive airway pressure has been shown to improve clinical symptoms, compliance with its use remains a problem and will be an area of future research.

Comparative study of membranes induced by PMMA or silicone in rats, and influence of external radiotherapy

The induced membrane technique has been used for long bone defect reconstruction after traumatism. One of the major drawbacks of this method is the difficult removal of the polymethyl methacrylate spacer after membrane formation. We therefore replaced the stiff PMMA spacer with a semi-flexible medical grade silicone spacer. This study aimed to compare subcutaneously formed membranes, induced by PMMA and silicone, in the irradiated or not irradiated areas within 28 rats that received the spacers. Histological analysis was performed to evaluate the composition of the membrane and to quantify the amount of vessels. Histomorphometric measurements were used to evaluate membranes' thickness, while fibrosis and inflammation were scored. The expression of VEGF and BMP-2 in lysates of the crushed membranes was determined by Western blotting. ALP expression was analyzed in HBMSC cultures in contact with the same lysates. Non-irradiated membranes induced by the two spacer types were non-inflammatory, fibrous and organized in layers. Irradiation did not change the macroscopic properties of membranes that were induced by silicone, while PMMA induced membranes were sensitive to the radiotherapy, resulting in thicker, strongly inflammatory membranes. Irradiated membranes showed an overall reduced osteogenic potential. Medical grade silicone is safe for the use in radiotherapy and might therefore be of great advantage for patients in need of cancer treatment.

Cutaneous immunopathology of long-standing complex regional pain syndrome

BACKGROUND

Both increased mast cells numbers and raised immune mediator concentrations indicate immune activation in the affected skin of patients with early complex regional pain syndrome (CRPS), but little is known about regional immune cell involvement in late-stage CRPS. The aim of the current study was to determine skin immune cell populations in long-standing CRPS.

METHODS

Using 6-mm skin punch biopsies from CRPS-affected and non-affected tissues, and a combination of chemical and immunofluorescence staining, we examined the density and function of key cell populations including mast cells, epidermal Langerhans cells (LCs) and tissue resident T-cells.

RESULTS

We found no significant differences in either overall immune cell infiltrates, or mast cell density between CRPS-affected and non-affected sub-epidermal tissue sections, contrasting recent findings in early CRPS by other groups. However, CD1a(+) LC densities in the epidermal layer were significantly decreased in affected compared to non-affected CRPS limbs (p < 0.01). T-cell clones isolated from CRPS-affected sub-epidermal tissues displayed a trend towards increased IL-13 production in ELISPOT assays when compared to T-cells isolated from non-affected areas, suggesting a Th2 bias.

CONCLUSIONS

Immune cell abnormalities are maintained in late-stage CRPS disease as manifest by changes in epidermal LC density and tissue resident T-cell phenotype.

TLR4-dependent immune response promotes radiation-induced liver disease by changing the liver tissue interstitial microenvironment during liver cancer radiotherapy

Liver tissue interstitial fluid (TIF) a special microenvironment around liver cells, which may play a vital role in cell communication during liver injury. Moreover, toll-like receptor 4 (TLR4) is an important trigger of the immune response that may also play a role in liver injuries, including radiation-induced liver disease (RILD). Therefore, the purpose of this study was to identify the roles of the TLR4-dependent immune response and TIFs in RILD after radiation therapy (RT) for liver cancer. This study consisted of two phases, and in the primary phase, the livers of TLR4 mutant (TLR4(-)) and normal (TLR4(+)) mice were irradiated with 30 Gy. TIF was then obtained from mouse livers and assessed by cytokine array analysis 20 days after irradiation, and cytokines in the TIFs, TLR4 and RILD were analyzed. In the second or validation phase, hepatocytes were isolated from TLR4(+) or TLR4(-) mice irradiated with 8 Gy and were co-cultured with TIFs from mouse livers, apoptosis of the hepatocytes was then measured using flow cytometry. We found that severe RILD was accompanied by higher expression of granulocyte macrophage colony-stimulating factor (GM-CSF), tumor necrosis factor-related apoptosis inducing ligand (TRAIL) and vascular endothelial growth factor receptor 2(VEGFR-2) in liver TIFs, from in TLR4(+) mice compared with TLR4(-) mice (P < 0.05). In both TLR4(+) and TLR4(-) hepatocytes, apoptosis after irradiaton was increased significantly after co-culture in TIFs from TLR4(+) mice that had their livers irradiated, compared with TIFs from TLR4(-) mice that had their livers irradiated or TIFs from unirradiated mice (P < 0.05). In summary, these findings indicate that the TLR4-dependent immune response may promote RILD by enhancing the expression of GM-CSF, VEGFR-2 and TRAIL in liver TIFs.

Immunological markers that predict radiation toxicity

Radiotherapy is a major modality of cancer treatment responsible for a large proportion of cancer that is cured. Radiation exposure induces an inflammatory response which can be influenced by genetic, epigenetic, tumour, health and other factors which can lead to very different treatment outcomes between individuals. Molecules involved in the immunological response provide excellent potential biomarkers for the prediction of radiation-induced toxicity. The known molecular and cellular immunological responses in relation to radiation and the potential to improve cancer treatment are presented in this review. In particular, immunological biomarkers of radiation-induced fibrosis and pneumonitis in cancer radiotherapy patients are discussed.

Comparative proteomic study reveals the molecular aspects of delayed ocular symptoms induced by sulfur mustard

Objective. Sulfur mustard (SM) is a highly reactive alkylating agent which produces ocular, respiratory, and skin damages. Eyes are the most sensitive organ to SM due to high intrinsic metabolic and rapid turnover rate of corneal epithelium and aqueous-mucous interfaces of the cornea and conjunctiva. Here we investigate underlying molecular mechanism of SM exposure delayed effects which is still a controversial issue after about 30 years. Materials and Methods. Following ethical approval, we have analyzed serum proteome of ten severe SM exposed male patients with delayed eye symptoms with two-dimensional electrophoresis followed by matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry. The western blotting was used to confirm the proteins that have been identified. Results. We have identified thirteen proteins including albumin, haptoglobin, and keratin isoforms as well as immunoglobulin kappa chain which showed upregulation while transferrin and alpha 1 antitrypsin revealed downregulation in these patients in comparison with healthy control group. Conclusions. Our results elevated participation of free iron circulatory imbalance and local matrix-metalloproteinase activity in development of delayed ocular symptoms induced by SM. It demonstrates that SM induced systemic toxicity leads to some serum protein changes that continually and gradually exacerbate the ocular surface injuries.

Effects of age and radiation treatment on function of extrinsic tongue muscles

Background

Radiation treatment for head and neck cancer often results in difficulty swallowing. Muscle weakness and fibrosis have been identified clinically as possible etiologies for swallowing problems following radiation. Aging may compound the effects of radiation on swallowing because radiation-induced damage to muscles and other tissues critical for the oropharyngeal swallow is overlaid on a declining sensorimotor system. However, there have been no investigations of the manner in which aging and radiation treatment effects combine to impact tongue muscles, which are critical effectors of the oropharyngeal swallow.

Methods

Thirty-seven male Fisher 344/Brown Norway rats were divided into four groups; young adults (9 month old), old (32 months old), young radiation (9 months), and old radiation (32 months old). Two fractions of 11 Gy on consecutive days was delivered by external beam radiation to the ventral side of the rat’s body over the anterior portion (20 X 30 mm area) of the anterior digastric muscle. Two-way analysis of variance (ANOVA) was used to examine the effects of age and radiation and their interaction on muscle contractile properties. Post-hoc testing was completed using Fisher’s least significant differences (LSD).

Results

Radiation was associated with a significant decrease in tongue force production and reduced speed of tongue muscle contraction. However, radiation treatment did not lead to muscle atrophy and fibrosis formation in the GG muscle. Radiation treatment did not exacerbate atrophic changes observed with aging, or lead to additional fibrosis formation in the GG muscle from that observed in the other groups.

Conclusions

The purpose of this research was to determine the effect of radiation on muscles of the tongue and to determine whether aging altered the extent of radiation injury to tongue muscles. Radiation was associated with a significant decrease in tongue force production and reduced speed of tongue muscle contraction, and the reduction in the speed of tongue muscle contraction was exacerbated in the aged-rat tongue. This work provides a foundation for future investigations of treatments for concurrent effects of aging and radiation on muscles of the tongue and swallowing.

Therapeutic potential of adipose stem cells in tissue repair of irradiated skeletal muscle in a rabbit model

The repairing function and differentiation potency of adipose stem cells (ASCs) transplantation following skeletal muscle injury induced by radiotherapy are still not well defined. In this study, one side of the buttocks of 64 New Zealand white rabbits underwent irradiation and were randomly divided into an ASCs group [5×10(7) ASCs labeled with CM-Dil and suspended in 1 mL of phosphate-buffered saline (PBS), via intramuscular injection] and a PBS group (1 mL of PBS, via intramuascular injection). ASCs were isolated in New Zealand white rabbits in vitro, and migration of ASCs labeled with CM-Dil was observed after transplantation in vivo. A significant decrease of histological severity scoring was found in irradiated tissue obtained in the ASCs group compared with that in PBS group. Additionally, compensatory hyperplasia was noted after ASCs transplantation in the injured tissues. Moreover, ASCs could upregulate the expression of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) and promote the angiogenesis of the injured tissues. Interestingly, myofilament-like structures were identified in irradiated muscle cells after ASCs transplantation. We concluded that ASCs transplantation could repair the radiation-induced skeletal muscle injury. Its mechanism may be, at least partly, associated with the upregulation of VEGF and bFGF, angiogenesis, promoting the compensatory hyperplasia of muscle satellite cells, as well as the myogenic differentiation.

SUV39H1 downregulation induces deheterochromatinization of satellite regions and senescence after exposure to ionizing radiation

While the majority of cancer patients are exposed to ionizing radiation during diagnostic and therapeutic procedures, age-dependent differences in radiation sensitivity are not yet well understood. Radiation sensitivity is characterized by the appearance of side effects to radiation therapy, such as secondary malignancies, developmental deficits, and compromised immune function. However, the knowledge of the molecular mechanisms that trigger these side effects is incomplete. Here we used an in vitro system and showed that low-senescent normal human diploid fibroblasts (WI-38) senesce in response to 5 Gy IR, while highly senescent cultures do not show changes in cell cycle regulation and only a slight increase in the percentage of senescent cells. Our study shows that this is associated with changes in the expression of genes responsible for cell cycle progression, apoptosis, DNA repair, and aging, as well as transcriptional and epigenetic regulators. Furthermore, we propose a role of the downregulation of SUV39H1 expression, a histone methyltransferase that specifically trimethylates H3K9, and the corresponding reduction in H3K9me3 levels in the establishment of IR-induced senescence.