Ionizing irradiation inhibits keloid fibroblast cell proliferation and induces premature cellular senescence

Effectiveness of postoperative superficial radiotherapy following the keloid-cross-flap surgery for auricular keloid: A prospective cohort study

BACKGROUND AND PURPOSE

Retaining partial keloid skin to make cross flaps (keloid-cross-flap surgery) is a modification of the core excision. This study aimed to compare the effectiveness of superficial radiotherapy versus compression therapy after keloid-cross-flap surgery.

MATERIALS AND METHODS

In this prospective cohort study, auricular keloid patients were consecutively screened from January 2019 to December 2021. They underwent keloid-cross-flap surgery and then enter either the superficial radiotherapy or the compression treatment group. The primary outcome was the one-year keloid recurrence rate. Secondary outcomes included: non-completion rate of adjuvant treatment; Patient and Observer Scar Assessment Scale (POSAS) scores and auricular aesthetics scores, evaluated by a four-point Likert scale (1 = poor to 4 = excellent) of non-recurring patients. Propensity score matching (PSM) was used to eliminate potential confounding factors.

RESULTS

123 patients were included in the superficial radiotherapy group and 128 in the compression treatment group. Non-completion rate was significantly higher in the compression treatment group (17.97 %), while the loss rate was comparable between the two groups. Overall, 13 patients (13.54 %) relapsed in superficial radiotherapy group, while 22 patients (25.58 %) in compression group (p < 0.05). After PSM, 59 patients in each group were analyzed, and the recurrence rate was lower in the superficial radiotherapy group (13.56 %). Of relapse-free patients, no significant difference was found in PSAS scores, OSAS scores or aesthetic scores between the two groups.

CONCLUSION

Keloid-cross-flap surgery could provide favorable morphologic repair of the auricular keloid, and postoperative superficial radiotherapy shows higher compliance and lower recurrence rate comparing to compression treatment.

Post-Excision Soft X-Ray Radiotherapy for Keloids: Experience in a Tertiary Referral Center

INTRODUCTION

Keloid is an abnormal proliferation of scar tissue that grows beyond the original margins of the injury. Even after complete resection, recurrences are common and pose a poorly understood challenge in dermatology. There is lack of large prospective clinical trials; thus, treatment recommendations are based on retrospective analyses and small cohort studies. Superficial radiotherapy is recommended in recurrent keloids; however, the successful treatment rates vary greatly. The aim of this study was to evaluate the keloid recurrence rate after post-excision soft X-ray radiotherapy and the associated factors.

METHODS

We reviewed retrospective data of all patients, treated with adjuvant post-excision soft X-ray radiotherapy with 12 Gy in 6 sessions at the tertiary referral center, Department of Dermatology, University Hospital Zurich, Switzerland, between 2005 and 2018. We analyzed individual keloids as separate cases. Successful treatment was defined as no sign of recurrence within 2 years.

RESULTS

Of the 200 identified patients, 90 met the inclusion criteria and were included in the final analysis. In 90 patients, 104 cases of treated keloids were analyzed. Keloids were mainly located on the trunk (49%) and were mostly caused by previous surgery (52.2%). 50% of the keloids did not relapse within 2 years after therapy. A significant factor leading to recurrence was the presence of previous therapy, with prior topical therapies, such as steroid injections or 5-fluorouracil, leading to most relapses. 69.2% of keloid cases who relapsed were pretreated. Soft X-ray radiotherapy was well tolerated, with posttreatment hyperpigmentation noted in 34% of patients, particularly in patients with non-Caucasian origin (61.3%).

CONCLUSION

Treatment of refractory keloids is difficult. Post-excision radiotherapy is an established adjuvant treatment option; nevertheless, recurrence rates are high, especially in pretreated keloids. Prospective studies determining the exact dosage and fraction of post-excisional radiotherapy are needed to determine the optimal radiation parameters.

The clinical efficacy of single-hole punch excision combined with intralesional steroid injection for nodular keloid treatment: a self-controlled trial

There are many methods to treat keloid, including various excision operations, laser, injection and radiotherapy. However, few studies have explored the effectiveness of single-hole punch excision in keloid treatment. This study aimed to investigate the efficacy and safety of lateral punch excision combined with intralesional steroid injection for keloid treatment through self-control trial. In this self-controlled trial, 50 patients meet the diagnosis of nodular keloid, and try to choose left-right symmetrical control, one skin lesion in the control group (50 skin lesionsin total) and the other in the observation group (50 skin lesions in total).The keloids in the treatment group were initially treated with punch excision combined with intralesional steroid injection, followed by injection treatment alone. Keloids in the control group received intralesional steroid injection alone. The Vancouver Scar Scale (VSS) of the keloid before and after the punch excision was evaluated; the keloid scores at different time points and the number of injection treatments required in both groups were compared, and adverse reactions were observed. The effective rate of the observation group was 86.0%, which was significantly higher than that of the control group (66.0%), and the recurrence rate of 22% was lower than that of the control group (χ2 = 4.141,63417), all of which were statistically significant (all P < 0.05). At the end of treatment, the VSS and total injection times in the observation group were significantly lower than those in the control group (t = 5.900,3.361), with statistical significance (P < 0.01). The combination of single-hole punch excision and intralesional steroid injection is an effective method to treat multiple nodular keloids, shortening the treatment course of tralesional steroid injection without obvious adverse reactions.

Diagnosis and Treatment of Keloid: Method Summary and Effect Evaluation

Keloid is a prevalent skin disorder characterized by the abnormal growth of keloid tissue, which usually occurs following wound healing or surgical incisions. It typically progresses through several stages: the inflammatory stage, the proliferative stage, collagen remodeling, and ultimately the formation of keloid. This review aims to summarize the diagnostic and therapeutic methods for keloid, and evaluate their effectiveness. The diagnosis of keloid is usually based on medical history and clinical manifestations such as pain, itching, erythema, and induration. Other commonly used diagnostic methods include tissue biopsy and ultrasound examination. Various treatment options for keloid exist, including physical therapy, medication, surgical treatment, and radiation therapy. Physical therapy includes pressure therapy, laser therapy, such as silicone sheets, elastic bandages, and laser irradiation. Medication treatment mainly involves the application of topical medications or intralesional injections, such as topical corticosteroids, 5-fluorouracil, and others. Radiation therapy can be administered using applicators and superficial radiation therapy, among other methods. The treatment outcomes of keloid vary from person to person and recurrence is common. Therefore, a comprehensive treatment approach may be the most effective strategy. Individualized treatment plans should consider factors such as the patient's age, gender, medical history, and the severity of the condition. In conclusion, the diagnosis and treatment of keloid require consideration of multiple factors and the implementation of individualized treatment plans. Future research should focus on identifying the molecular mechanisms underlying the occurrence and progression of keloid in order to develop more effective treatment methods.

Progress in the clinical treatment of keloids

Keloid is a pathological scar that is higher than the skin surface following skin damage. Its lesion range often extends beyond the original damage boundary and does not naturally subside over time. Its pathogenesis is very complex, currently the main causes include fibroblast excessive proliferation, collagen and extracellular matrix (Extracellular matrix, ECM) excessive deposition, excessive angiogenesis, and so on. The traditional treatment method primarily involves surgical intervention, but it is associated with a high recurrence rate post-surgery. Consequently, many treatment methods are derived according to the different clinical characteristics of keloid. This paper will review the therapeutic progress in recent years from surgical treatment, physiotherapy, drug therapy, and biological therapy, with the goal of offering valuable insights for the clinical treatment of keloids.

Cellular senescence: a double-edged sword in cancer therapy

Over the past few decades, cellular senescence has been identified in cancer patients undergoing chemotherapy and radiotherapy. Senescent cells are generally characterized by permanent cell cycle arrest as a response to endogenous and exogenous stresses. In addition to exiting the cell cycle process, cellular senescence also triggers profound phenotypic changes such as senescence-associated secretory phenotype (SASP), autophagy modulation, or metabolic reprograming. Consequently, cellular senescence is often considered as a tumor-suppressive mechanism that permanently arrests cells at risk of malignant transformation. However, accumulating evidence shows that therapy-induced senescence can promote epithelial-mesenchymal transition and tumorigenesis in neighboring cells, as well as re-entry into the cell cycle and activation of cancer stem cells, thereby promoting cancer cell survival. Therefore, it is particularly important to rapidly eliminate therapy-induced senescent cells in patients with cancer. Here we review the hallmarks of cellular senescence and the relationship between cellular senescence and cancer. We also discuss several pathways to induce senescence in tumor therapy, as well as strategies to eliminate senescent cells after cancer treatment. We believe that exploiting the intersection between cellular senescence and tumor cells is an important means to defeat tumors.

Hypertrophic Scars and Keloids: Advances in Treatment and Review of Established Therapies

Hypertrophic scars and keloids can have significant detrimental effects on patients both psychosocially and functionally. A careful identification of patient risk factors and a comprehensive management plan are necessary to optimize outcomes. Patients with a history of dystrophic scarring should avoid unnecessary procedures and enhance the wound-healing process using various preventive strategies. As there is no single, fully efficacious treatment modality, prevention remains the best approach in reducing aberrant scar formation. When prevention therapies fail, keloids have been shown to be respond to a variety of therapies including topical and injectable corticosteroids, 5-fluorouracil, radiotherapy, lasers, and surgical excision, all with varying efficacies. As such, management should be tailored to the individual patient's risk factors with the use of combination therapies to reduce recurrence rates. Still, keloid and hypertrophic scar therapies are widely diverse with novel treatment modalities providing alternatives for recurring lesions. Laser-assisted drug delivery, skin priming, and novel topical therapies may provide alternative options for the management of hypertrophic scars and keloids.

Treatment of Keloids with Surgery and Immediate Postoperative Radiotherapy: Knowledge Gained Over 17 Years

Background The treatment of keloidal scars with radiotherapy has been practiced for more than a century. Radiotherapy post-surgery has been deemed necessary and effective in preventing recurrence but still, no clear guidelines exist as to the best modality of radiotherapy, the ideal dose, and the time it should be given for keloidal scars. The purpose of this study is to confirm the effectiveness of this treatment and address these issues.

Methods Since 2004, 120 patients presenting with keloidal scars were seen by the author. Out of them, 50 were managed with surgery followed by HDR brachytherapy/electron beam radiotherapy delivering 2000 rads to the scar within 24 hours of surgery. Patients were followed up for at least 18 months to assess the scar status and the recurrence of keloids. Recurrence was defined as the appearance of a nodule or an obvious return of the keloid within 1 year of treatment.

Results Three patients developed a nodule in the scar, which was deemed a recurrence, making an incidence of 6%. There was no major problem after immediate postoperative radiotherapy. Five patients had delayed healing at 2 weeks and a hypertrophic scar was noted in five patients at 4 weeks that settled with conservative measures.

Conclusion Treating the vexing problem of keloids with surgery and immediate postoperative radiotherapy is safe and effective. We recommend that this be adopted as the standard treatment in keloid management.

Current advances in the selection of adjuvant radiotherapy regimens for keloid

Keloid is a common benign skin tumor in the outpatient department, and patients are often accompanied by itching and pain. Since the pathogenesis is unknown, the effect of single method treatment is unsatisfactory, and therefore the recurrence rate is high. Therefore, comprehensive treatment is mostly used in clinical treatment. Adjuvant radiotherapy is currently one of the most effective treatments for keloid. After long-term clinical practice, brachytherapy and electron beam radiotherapy has increasingly become the gold standard of treatment, because brachytherapy provides more focused radiation treatment to focal tissue to significantly reduce recurrence rate, and better preserve normal tissue. With the development of new radiotherapy techniques, more options for the treatment of keloid. Currently, adjuvant radiotherapy has been widely recognized, but there is no consensus on the optimal protocol for adjuvant radiotherapy for keloids. This review provides a review of published treatment options and new radiotherapy techniques for adjuvant radiotherapy of keloids and gives a comprehensive evaluation for clinical treatment.

Cellular Senescence in Aging, Tissue Repair, and Regeneration

SUMMARY

Society and our healthcare system are facing unprecedented challenges due to the expansion of the older population. As plastic surgeons, we can improve care of our older patients through understanding the mechanisms of aging that inevitably impact their outcomes and well-being. One of the major hallmarks of aging, cellular senescence, has recently become the focus of vigorous research in academia and industry. Senescent cells, which are metabolically active but in a state of stable cell cycle arrest, are implicated in causing aging and numerous age-related diseases. Further characterization of the biology of senescence revealed that it can be both detrimental and beneficial to organisms depending on tissue context and senescence chronicity. Here, we review the role of cellular senescence in aging, wound healing, tissue regeneration, and other domains relevant to plastic surgery. We also review the current state of research on therapeutics that modulate senescence to improve conditions of aging.

Molecular Response of Keloids to Ionizing Radiation: Targeting FOXO1 Radiosensitizes Keloids

PURPOSE

Keloids are benign dermal tumors that arise from abnormal wound healing processes following skin lesions. Surgical excision followed by radiotherapy plays an important role in the treatment of keloids. Nevertheless, radioresistance remains a serious impediment to treatment efficacy. Investigation of the molecular response of keloids to radiation may contribute to radiosensitizing strategies.

MATERIALS AND METHODS

Primary keloid fibroblasts from human keloids were isolated and irradiated with X-ray. The expression profiles of messenger RNA (mRNA) in nonradiated and irradiated primary keloid fibroblasts were measured by mRNA sequencing analysis. Then, we identified common motifs and corresponding transcription factors of dysregulated mRNAs by using bioinformatic analysis of the proximal promoters. Whereafter, GO and KEGG were used to analyse the functional enrichment of the differentially expressed genes.

RESULTS

We found that radiation not only suppressed proliferation but also increased cell senescence of primary keloid fibroblasts. There were 184 mRNAs and 204 mRNAs that showed significant changes in 4 and 8 Gy irradiated primary keloid fibroblasts, respectively. Among them, 8 upregulated and 30 downregulated mRNAs showed consistent alterations in 4 and 8 Gy irradiated primary keloid fibroblasts. More importantly, the forkhead box O1 (FOXO1) signaling pathway was involved in the irradiation response. Pretreatment with the FOXO1 signaling inhibitor AS1842856 significantly promoted LDH release, apoptosis and senescence of primary keloid fibroblasts following irradiation.

CONCLUSION

Our findings illustrated the molecular changes in human keloid fibroblasts in response to radiation, and FOXO1 pathway inhibition is expected to provide a novel strategy for the radiosensitization of keloids.

Loureirin A Exerts Antikeloid Activity by Antagonizing the TGF-β1/Smad Signalling Pathway

It has been recently shown that loureirin A (LA), a major active component of resina draconis, might be effective in the prevention and treatment of liver fibrosis. We examined whether LA could inhibit the formation of keloids. To investigate the pharmacological effects of loureirin A on keloid formation and the underlying mechanisms. CellTiter-Blue viability assays were used to examine the proliferation of keloid fibroblasts (KFs) that were treated with LA. Fibroblast migration was evaluated using a cell migration assay. Immunofluorescence staining was used to measure the expression of α-SMA in KFs. RT-qPCR was used to evaluate the mRNA expression of Col-I, Col-III, α-SMA, Bax, and Caspase-3, while Western blotting was used to evaluate the protein expression of Col-I, Col-III, α-SMA, Bax, Caspase-3, p-Smad2, and p-Smad3. LA inhibited the proliferation of KFs and suppressed the migration and TGF-β1-induced myofibroblast differentiation of KFs. In addition, LA downregulated the mRNA and protein levels of Col-I, Col-III, and α-SMA while promoting the mRNA and protein levels of Bax and Caspase-3. Moreover, LA downregulated the protein levels of p-Smad2 and p-Smad3 in cultured TGF-β1-treated KFs ex vivo. These results show that LA has an antikeloid effect on KFs by suppressing the TGF-β1/Smad signalling pathway. Our findings suggest that LA may be a potential candidate drug for the prevention and treatment of keloids.

Downregulation of PLK4 expression induces apoptosis and G0/G1-phase cell cycle arrest in keloid fibroblasts

Objectives

Keloids are benign fibroproliferative tumors that display many cancer‐like characteristics, such as progressive uncontrolled growth, lack of spontaneous regression, and extremely high rates of recurrence. Polo‐like kinase 4 (PLK4) was recently identified as a master regulator of centriole replication, and its aberrant expression is closely associated with tumorigenesis. This study aimed to investigate the expression and biological role of PLK4 in the pathogenesis of keloids.

Materials and Methods

We evaluated the expression of PLK4 in keloids and adjacent normal skin tissue samples. Then, we established PLK4 knockdown and overexpression cell lines in keloid fibroblasts (KFs) and normal skin fibroblasts (NFs), respectively, to investigate the roles of PLK4 in the regulation of proliferation, migration, invasion, apoptosis, and cell cycle in KFs. Centrinone B (Cen‐B), a highly selective PLK4 inhibitor, was used to inhibit PLK4 activity in KFs to evaluate the therapeutic effect on KFs.

Results

We discovered that PLK4 was overexpressed in keloid dermal samples and KFs compared with adjacent normal skin samples and NFs derived from the same patients. High PLK4 expression was positively associated with the proliferation, migration, and invasion of KFs. Furthermore, knockdown of PLK4 expression or inhibition of PLK4 activity by Cen‐B suppressed KF growth, induced KF apoptosis via the caspase‐9/3 pathway, and induced cell cycle arrest at the G0/G1 phase in vitro.

Conclusions

These findings demonstrate that PLK4 is a critical regulator of KF proliferation, migration, and invasion, and thus, Cen‐B is a promising candidate drug for keloid treatment.

Nuclear medicine in the management of superficial skin abnormalities and institutional experience

Keloid, hypertrophic scars and basal cell carcinoma (BCC) falls under the category of non-melanoma skin cancer. Intralesional steroids, external beam radiation therapy, 5-Fluorouracil, cryotherapy, laser, etc are the available treatment options. However, recurrence has been reported with each type of treatment mode. In the present article, various treatment modes have been discussed and institutional experience of Rhenium-188 skin patches for the treatment of keloids and BCC has been discussed.

Treatment of hypertrophic scar with injection of triamcinolone leads to increased microRNA-26a in a rabbit ear model

Objectives:

Differential expression of microRNAs (miRNAs) has been confirmed to promote hypertrophic scar (HS) formation. However, this mechanism remains to be further elucidated. This paper investigated the effects of microRNA26a on HS of rabbit ears or its mechanism.

Methods:

The rabbit HS models were established and randomly assigned to either the experimental group (20 rabbits with treatment through triamcinolone acetonide) or the scar group (20 rabbits without treatment). In addition, 10 unmodeled rabbits were served as control group. The expression of microRNA-26a in HS tissues was detected via a stem-loop real-time polymerase chain reaction (RT-PCR).

Results:

According to RT-PCR, we showed the decreased expression of microRNA-26a in the scar group compared with that in the experimental group, and in the experimental group compared with that in the control group ( p < .01). In addition, the expression of microRNA-26a was negatively correlated with scar thickness (STs), number of fibroblasts (NFs), Collagen I (Col I) level, Collagen III (Col III) level, Interleukin-6 (IL-6) level, and Tumor necrosis factor-alpha (TNF-α) level (all p < .01).

Conclusions:

Our findings revealed that the increase of microRNA-26a expression might alleviate excessive inflammation during the HS formation, inhibit fibroblast proliferation and collagen deposition in HS, and promote the treatment of HS.

Dental pulp stem cell-derived small extracellular vesicle in irradiation-induced senescence

Small extracellular vesicles (sEV) facilitate signaling molecule transfer among cells. We examined the therapeutic efficacy of human dental pulp stem cell-derived sEV (hDPSC-sEV) against cellular senescence in an irradiated-submandibular gland mouse model. Seven-week-old mice were exposed to 25 Gy radiation and randomly assigned to control, phosphate-buffered saline (PBS), or hDPSC-sEV groups. At 18 days post-irradiation, saliva production was measured; histological and reverse transcription-quantitative PCR analyses of the submandibular glands were performed. The salivary flow rate did not differ significantly between the PBS and hDPSC-sEV groups. AQP5-expressing acinar cell numbers and AQP5 expression levels in the submandibular glands were higher in the hDPSC-sEV group than in the other groups. Furthermore, compared with non-irradiated mice, mice in the 25 Gy + PBS group showed a high senescence-associated-β-galactosidase-positive cell number and upregulated senescence-related gene (p16^INK4a, p19^Arf, p21) and senescence-associated secretory phenotypic factor (MMP3, IL-6, PAI-1, NF-κB, and TGF-β) expression, all of which were downregulated in the hDPSC-sEV group. Superoxide dismutase levels were lower in the PBS group than in the hDPSC-sEV group. In summary, hDPSC-sEV reduced inflammatory cytokine and senescence-related gene expression and reversed oxidative stress in submandibular cells, thereby preventing irradiation-induced cellular senescence. Based on these results, we hope to contribute to the development of innovative treatment methods for salivary gland dysfunction that develops after radiotherapy for head and neck cancer.

Immediate Postoperative Treatment of Keloids with Intraoperative Radiation Therapy Technology: A Pilot Study

Background

The combination of surgery and postoperative radiotherapy allows for the most effective results with keloids. In this trial, surgery and intraoperative radiation therapy (IORT) technology were used-the hypothesis being that the earlier the application of postoperative radiotherapy, the better the wound healing evolution.

Methods

The study included 16 patients with 21 keloids. The keloids were radically excised and repaired with direct suture or local skin flaps. Collimated electron radiotherapy was applied within 45 minutes of surgery. The outcomes were assessed according to the modified Patient and Observer Scar Assessment Scale; the modified Vancouver Scar Scale; and the modified Common Terminology Criteria for Adverse Events v. 4.0 for skin and subcutaneous tissue disorders.

Results

Recurrences were observed in one out of 16 patients, and in two out of 21 keloids (9.5%). The modified Patient and Observer Scar Assessment Scale demonstrated a statistically significant improvement in pain, itching, color, stiffness, thickness, and irregularity after the treatment. The modified Patient and Observer Scar Assessment Scale displayed a statistically significant improvement in the scar vascularity, pigmentation, thickness, and pliability after the treatment. The modified Vancouver Scar Scale demonstrated a statistically significant improvement in 90.48% of the scars after the treatment. The modified Common Terminology Criteria for Adverse Events v. 4.0 for skin and subcutaneous tissue disorders demonstrated an improvement in erythema multiforme and skin pain across the whole sample, with a temporary hyperpigmentation in 19% of the scars after the treatment.

Conclusion

The combination of surgery and collimated electron radiotherapy with IORT technology demonstrated favorable results in 90.5% of the cases.

Autophagy and senescence: Insights from normal and cancer stem cells

Autophagy is a fundamental cellular process, which allows cells to adapt to metabolic stress through the degradation and recycling of intracellular components to generate macromolecular precursors and produce energy. Autophagy is also critical in maintaining cellular/tissue homeostasis, as well preserving immunity and preventing human disease. Deregulation of autophagic processes is associated with cancer, neurodegeneration, muscle and heart disease, infectious diseases and aging. Research on a variety of stem cell types establish that autophagy plays critical roles in normal and cancer stem cell quiescence, activation, differentiation, and self-renewal. Considering its critical function in regulating the metabolic state of stem cells, autophagy plays a dual role in the regulation of normal and cancer stem cell senescence, and cellular responses to various therapeutic strategies. The relationships between autophagy, senescence, dormancy and apoptosis frequently focus on responses to various forms of stress. These are interrelated processes that profoundly affect normal and abnormal human physiology that require further elucidation in cancer stem cells. This review provides a current perspective on autophagy and senescence in both normal and cancer stem cells.

A retrospective study of hypofractionated radiotherapy for keloids in 100 cases

At present, the consensus on the best treatment for keloids is the combination of clinical and surgical therapies, if necessary, associated with adjuvant radiotherapy like brachytherapy. Whereas, the uniform scheme of radiotherapy in keloids is unclear. Here, we conducting a retrospective analysis to assess the efficacy and safety of a specific treatment regimen (20 Gy in 5 fractions) in keloid patients. We retrospectively analysed the medical records of keloid patients receiving auxiliary postoperative radiotherapy (PORT) treatment from 2009 to 2019. The patients were treated with the hypofractionation method of 20 Gy in 5 fractions. We compared the local control rate and complications, using the chi-square test and logistic regression analyses. After screening, we identified 100 keloid patients in this study, with a median follow-up of 59 months. In this study, the overall local control rate of keloid lesions was 84.8%. After multivariate analyses (primary keloid or not, family history, interval from surgery to irradiation and site), our research showed that primary keloid, site and interval from surgery to irradiation were significantly related to recurrence. Acute radiation injury and late radiation injury accounted for 3% (erythema) and 1% (skin sclerosis) of the total cases, respectively. Our results indicate that a postoperative hypofractionation with radiation dose of 20 Gy in 5 fractions may be effective, easy to accept and safe for keloid patients.

FK866 Protects Human Dental Pulp Cells against Oxidative Stress-Induced Cellular Senescence

FK866 possesses various functional properties, such as anti-angiogenic, anti-cancer, and anti-inflammatory activities. We previously demonstrated that premature senescence of human dental pulp cells (hDPCs) was induced by hydrogen peroxide (H₂O₂). The present study aimed to investigate whether H₂O₂-induced premature senescence of hDPCs is affected by treatment with FK866. We found that FK866 markedly inhibited the senescent characteristics of hDPCs after exposure to H₂O₂, as revealed by an increase in the number of senescence-associated β-galactosidase (SA-β-gal)-positive hDPCs and the upregulation of the p21 and p53 proteins, which acts as molecular indicators of cellular senescence. Moreover, the stimulatory effects of H₂O₂ on cellular senescence are associated with oxidative stress induction, such as excessive ROS production and NADPH consumption, telomere DNA damage induction, and upregulation of senescence-associated secretory phenotype factors (IL-1β, IL-6, IL-8, COX-2, and TNF-α) as well as NF-κB activation, which were all blocked by FK866. Thus, FK866 might antagonize H₂O₂-induced premature senescence of hDPCs, acting as a potential therapeutic antioxidant by attenuating oxidative stress-induced pathologies in dental pulp, including inflammation and cellular senescence.

Tomotherapy as an Alternative Irradiative Treatment for Complicated Keloids

The aim of this study was to investigate the treatment of complicated keloids with helical tomotherapy (HT) and electron beam radiotherapy. From July 2018 to September 2018, 11 patients with 23 keloid lesions treated with HT were enrolled. Additionally, 11 patients with 20 lesions treated with electron beam radiotherapy in the same period were enrolled. Patients in both groups were treated within 24 h after surgical excision of the keloid lesion with 13.5 Gy in three consecutive daily fractions. The median follow-up period was 15 months. The local control rate was 91.3% and 80% in the HT group and the electron beam group, respectively. No acute adverse effects were observed in either group, but most patients exhibited pigmentation. No radiation-induced cancer occurred in these patients up to the time of this report. Pain and pruritus improved for all patients and more obviously for three patients with complicated keloids treated with HT. The measured surface dose was 103.7–112.5% and 92.8–97.6% of the prescribed dose in the HT group and the electron beam group, respectively. HT can be considered an alternative in cases where it is not feasible to use multiple electron fields, due to encouraging clinical outcomes.

Assessing keloid recurrence following surgical excision and radiation

Keloids are a fibroproliferative disorder that can result from a cutaneous injury to the reticular dermis. Recurrence rates as high as 100% have been reported following surgical excision alone. Consequently, a variety of post-surgical techniques have been employed to prevent keloid recurrence, including the use of radiation. Although numerous studies have shown post-excisional X-rays, electron beam, lasers and brachytherapy can reduce the rate of keloid recurrence, numerous inconsistencies, including a wide range of definitions for keloid recurrence, make it difficult to compare study outcomes. The review aims to examine the various means for defining keloid recurrence in clinical trials involving the use of radiation therapy. Searches of the Cochrane Library and PubMed were performed to identify the available information for post-surgical keloid recurrence following radiation therapy. Each identified study was reviewed for patient follow-up and criteria used to define keloid recurrence. The search results included clinical studies with external beam radiation, brachytherapy and superficial radiation therapy. Many studies did not include a definition of keloid recurrence, or defined recurrence only as the return of scar tissue. Other studies defined keloid recurrence based on patient self-assessment questionnaires, symptoms and scar elevation and changes in Kyoto Scar Scale, Japan Scar Workshop Scale and Vancouver Scar Scale scores. The results of this review indicate keloidectomy followed by radiation therapy provide satisfactory recurrence rates; however, clinical studies evaluating these treatments do not describe treatment outcomes or use different definitions of keloid recurrence. Consequently, recurrence rates vary widely, making comparisons across studies difficult. Keloid recurrence should be clearly defined using both objective and subjective measures.

The Effects of Timing of Postoperative Radiotherapy on Hypertrophic Scar in a Rabbit Model

Background

Hypertrophic scar is associated with excessive proliferation of fibroblasts, the accumulation of collagen fibers, and angiogenesis associated with chronic inflammation. Scar resection, combined with radiotherapy, is widely used in clinical practice, but timing remains controversial. This study aimed to investigate the association between the timing of postoperative radiotherapy and the effects on hypertrophic scar in a rabbit model.

Material/Methods

Forty New Zealand white rabbits, 8–12 months old, weighing 1.8–2.3 kg were used in the model of hypertrophic scar and underwent surgical resection with or without postoperative radiotherapy. The study groups included: Group 1, the non-resection group; Group 2, the resection and non-radiotherapy group; Group 3, the immediate postoperative radiotherapy group; Group 4, the 12-hour postoperative radiotherapy group; Group 5, the 24-hour postoperative radiotherapy group; Group 6, the 48-hour postoperative radiotherapy group; Group 7, the 72-hour postoperative radiotherapy group; and Group 8, the 120-hour postoperative radiotherapy group. The rabbit ear skin was observed after treatment, and the hypertrophic scar index (HI), fibroblast numerical area density (NA), and collagen fiber area density (AA) were determined.

Results

The HI, NA, and AA were significantly lower after 48 hours of postoperative radiotherapy (P<0.05), with the effects occurring mainly within 24 hours. There was no difference in HI, NA, and AA between the radiotherapy and non-radiotherapy groups within 24 hours after surgery.

Conclusions

In a rabbit model of hypertrophic scar, surgical resection combined with radiotherapy resulted in an optimal effect within 24 hours after surgery.

Senescent Cells in Cancer Therapy: Friends or Foes?

Several cancer interventions induce DNA damage and promote senescence in cancer and nonmalignant cells. Senescent cells secrete a collection of proinflammatory factors collectively termed the senescence-associated secretory phenotype (SASP). SASP factors are able to potentiate various aspects of tumorigenesis, including proliferation, metastasis, and immunosuppression. Moreover, the accumulation and persistence of therapy-induced senescent cells can promote tissue dysfunction and the early onset of various age-related symptoms in treated cancer patients. Here, we review in detail the mechanisms by which cellular senescence contributes to cancer development and the side effects of cancer therapies. We also review how pharmacological interventions to eliminate senescent cells or inhibit SASP production can mitigate these negative effects and propose therapeutic strategies based on the age of the patient.

Combined surgical excision and electron external beam radiation improves the treatment of keloids: A descriptive study

Keloids are firm, fibrous nodules that form on an individual's skin and are associated with difficult symptoms as well as high recurrence rates. This study aims to improve the surgical techniques that reduce local tension after surgical excision of keloids as well as applying adjuvant radiotherapy to suppress scar formation. A total of 58 patients aged between 21 and 76 years received surgical incision of keloid and immediate postoperation low-dose radiotherapy. All patient follow-ups were performed at the out-patient department. Any sign of a keloid at the incision site was defined as treatment failure or keloid recurrence, regardless of the size. At a median follow-up of 22 months, the overall recurrence for all lesions was 8.6%, which is improved compared with previous study. In addition, all incisions performed during surgeries were healed and no signs of necrosis or the development of ulcers was observed. Our study suggests that this combined therapy provides excellent local control of keloids and shows promise for future therapy.

Irradiation-induced senescence of bone marrow mesenchymal stem cells aggravates osteogenic differentiation dysfunction via paracrine signaling

The role of cellular senescence induced by radiation in bone loss has attracted much attention. As one of the common complications of anticancer radiotherapy, irradiation-induced bone deterioration is common and clinically significant, but the pathological mechanism has not been elucidated. This study was performed to explore the cellular senescence and senescence-associated secretory phenotype (SASP) induction of bone marrow-derived mesenchymal stem cells (BMSCs) by irradiation and its role in osteogenic differentiation dysfunction. It was observed that irradiated BMSCs lost typical fibroblast-like morphology, exhibited suppressed viability and differentiation potential accompanied with senescence phenotypes, including an increase in senescence-associated β-galactosidase (SA-β-gal) staining-positive cells, and upregulated senescence-related genes p53/p21, whereas no changes happened to p16. Additionally, DNA damage γ-H2AX foci, G0/G1 phase of cell cycle arrest, and cellular and mitochondrial reactive oxygen species (ROS) increased in an irradiation dose-dependent manner. Meanwhile, the JAK1/STAT3 pathway was activated and accompanied by an increase in SASP secretion, such as IL-6, IL-8, and matrix metalloproteinase-9 (MMP9), whereas 0.8 μM JAK1 inhibitor (JAKi) treatment effectively inhibited the JAK pathway and SASP production. Furthermore, conditioned medium (CM) from irradiation-induced senescent (IRIS) BMSCs exhibited a markedly reduced ability in osteogenic differentiation and marker gene expression of osteoblasts, whereas CM with JAKi intervention may effectively improve these deterioration effects. In conclusion, irradiation could provoke BMSC senescence and SASP secretion and further aggravate osteogenic differentiation dysfunction via paracrine signaling, whereas SASP targeting may be a possible intervention strategy for alleviating irradiation-induced bone loss.

Strategies to prevent hypertrophic scar formation: a review of therapeutic interventions based on molecular evidence

Once scar tissues mature, it is impossible for the surrounding tissue to regenerate normal dermal tissue. Therefore, it is essential to understand the fundamental mechanisms and establish effective strategies to inhibit aberrant scar formation. Hypertrophic scar formation is considered a result of the imbalance between extracellular matrix synthesis and degradation during wound healing. However, the underlying mechanisms of hypertrophic scar development are poorly understood. The purpose of this review was to outline the management in the early stage after wound healing to prevent hypertrophic scar formation, focusing on strategies excluding therapeutic agents of internal use. Treatment aimed at molecular targets, including cytokines, will be future options to prevent and treat hypertrophic scars. More basic studies and clinical trials, including combination therapy, are required to investigate the mechanisms and prevent hypertrophic scar formation.

Keloids: Current and emerging therapies

Keloids are pathological scars that grow over time and extend beyond the initial site of injury after impaired wound healing. These scars frequently recur and rarely regress. They are aesthetically disfiguring, can cause pain, itching, discomfort as well as psychological stress, often affecting quality of life. Many treatment modalities, including surgical and non-surgical, have been explored and have been reported to be beneficial; however, none have been absolutely satisfactory or optimal for the treatment of all keloid subtypes to date. This poses a major challenge to clinicians. Often, a combinational therapeutic approach appears to offer the best results with higher patient satisfaction compared to monotherapy. The aetiopathogenesis of keloids is not fully elucidated; however, with recent advances in molecular biology and genetics, insight is being gained on the complex process of scar formation and hence new therapeutic and management options for keloids. In this paper, we explore the literature and summarise the general concepts surrounding keloid development and review both current (corticosteroids, surgical excision, silicone-based products, pressure therapy, radiotherapy, cryotherapy, laser therapy, imiquimod and 5-fluorouracil) and emerging (stem cell therapy, mitomycin C, verapamil, interferons, bleomycin, botulinum toxin type A and angiotensin-converting enzyme inhibitors) treatments. Increased knowledge and understanding in this area may potentially lead to the discovery and development of novel therapeutic options that are more efficacious for all keloid types.

LAY SUMMARY

Keloids are problematic scars that are difficult to treat and manage. The aetiopathogenesis of keloids is not clear; however, recent advances in molecular biology and genetics are beginning to shed light on the underlying mechanisms implicated in keloid scar formation which will hopefully lead to the development of treatment options for all keloid types. This review summarises current and emerging therapies.

Z-plasty and Postoperative Radiotherapy for Anterior Chest Wall Keloids: An Analysis of 141 Patients

Background

The therapies for anterior chest wall keloids include surgical excision, postoperative radiotherapy, silicone taping stabilization, and steroid plaster. However, to date, there is no universally accepted combination treatment strategy for anterior chest wall keloids.

Methods

All consecutive patients with single or multiple anterior chest wall keloids who underwent keloid excision, tension-reducing suturing, z-plasty, and postoperative radiotherapy in 2013-2016 in Nippon Medical School were included in this case series study. Only keloids that arose from small injuries such as folliculitis or acne were selected. The surgery was followed by tension-reducing self-management of the wounds with silicone tape and steroid plaster. The postsurgical radiotherapy modality was 18 Gy administered in 3 fractions over 3 days. The primary study outcome was keloid recurrence during the 24-month follow-up period. Recurrence was defined as the development of stiff and red lesions in even a small part of the scar that did not respond to 6 months of steroid plaster therapy.

Results

In total, 141 patients with 141 lesions were enrolled. Of the 141 lesions, 15 (10.6%) recurred. All recurrences were successfully treated by steroid plaster and steroid injection. The recurrence patients did not differ from the nonrecurrence patients in terms of the size of the original keloid or gender distribution.

Conclusions

Anterior chest wall keloids can be successfully treated by customized plans that involve appropriate surgical modalities (including z-plasty) followed by postoperative radiotherapy (18 Gy in 3 fractions over 3 days) and scar self-management with silicone tape and steroid plaster.

Cancer driver mutations in endometriosis: Variations on the major theme of fibrogenesis

BACKGROUND

One recent study reports cancer driver mutations in deep endometriosis, but its biological/clinical significance remains unclear. Since the natural history of endometriosis is essentially gradual progression toward fibrosis, it is thus hypothesized that the six driver genes reported to be mutated in endometriosis (the RP set) may play important roles in fibrogenesis but not necessarily malignant transformation.

METHODS

Extensive PubMed search to see whether RP and another set of driver genes not yet reported (NR) to be mutated in endometriosis have any roles in fibrogenesis. All studies reporting on the role of fibrogenesis of the genes in both RP and NR sets were retrieved and evaluated in this review.

RESULTS

All six RP genes were involved in various aspects of fibrogenesis as compared with only three NR genes. These nine genes can be anchored in networks linking with their upstream and downstream genes that are known to be aberrantly expressed in endometriosis, piecing together seemingly unrelated findings.

CONCLUSIONS

Given that somatic driver mutations can and do occur frequently in physiologically normal tissues, it is argued that these mutations in endometriosis are not necessarily synonymous with malignancy or premalignancy, but the result of enormous pressure for fibrogenesis.

[Effectiveness of internal mammary artery perforator propeller flap repair combined with radiotherapy for chest keloid in female patients]

Objective

To investigate the effectiveness of internal mammary artery perforator (IMAP) propeller flap repair combined with radiotherapy for chest keloid in female patients.

Methods

Between January 2015 and December 2016, 15 female patients with chest keloids were treated, aged 28-75 years (mean, 45.2 years). The keloid disease duration was 1-28 years (median, 6 years). The causes of disease included secondary keloid caused by folliculitis in 7 cases, cardiac surgery in 4 cases, skin abrasion in 2 cases, mosquito bite in 1 case, and unknown etiology in 1 case. The size of keloid ranged from 5 cm×3 cm to 17 cm×6 cm. The IMAP propeller flaps were used to repair the defects after chest keloid excision. The size of flaps ranged from 7 cm×5 cm to 14 cm×8 cm. The donor sits were sutured directly. The routine radiotherapy was performed after operation.

Results

All IMAP propeller flaps survived well, and the donor site healed by first intention. All 15 patients were followed up 12-24 months (mean, 16 months). No telangiectasia or incision dehiscence occurred. No radiation-related carcinogenesis occurred during follow-up. The patients were satisfied with the breast shape and symmetry after operation. The symptoms of pain and itching were relieved at keloid area in 13 cases (86.7%), with no obvious recurrence of keloid at the donor site and the primary site. Only 2 cases (13.3%) recurred and were treated with continuously conservative treatment.

Conclusion

IMAP propeller flap is an ideal reconstruction method for repairing the wounds after chest keloid excision in female patients, which can preserve the good breast shape. The IMAP propeller flap repair combined with early postoperative radiotherapy can effectively reduce the recurrence rate, and the effectiveness is satisfactory.

Superficial radiation therapy in peyronie's disease: An effective and well-tolerated therapy

Purpose

This study aimed to assess the safety, efficacy, and patient satisfaction of superficial radiation therapy in the treatment of Peyronie's disease (PD) in a retrospective analysis.

Methods and materials

We performed a retrospective analysis of 83 patients who underwent radiation therapy between 1999 and 2008 with 8 fractions of 4 Gy over a period of 6 months. With a mean follow-up time of 52 months, patients responded to a comprehensive questionnaire that covered patient characteristics, disease duration before radiation therapy, course of disease, treatment response, side effects, and patient satisfaction.

Results

After a mean follow-up time of 52 months, 78% of the treated patients reported that PD progression had stopped. Furthermore 47% of patients had a symptom regression. Only 7% of patients reported PD progression. The penile curvature was improved in 49% of patients, and plaque induration could be reduced in 42% of patients. Moreover, 71% of patients reported substantial pain relief, as measured by a visual analogue scale (1 = not satisfied; 10 = very satisfied). Treatment satisfaction was rated with a median of 8 in a visual analogue scale out of 10. Side effects included transient erythema in 38.6% of patients and 9.6% reported of transient or chronic dryness. No severe side effects were observed.

Conclusions

Radiation therapy for PD in the disease's early stages proved to be a safe and well-tolerated method with good results in pain relief, especially in patients aged <62 years. No serious adverse events or malign transformations are expected using doses up to 32 Gy.

Recent Understandings of Biology, Prophylaxis and Treatment Strategies for Hypertrophic Scars and Keloids

Hypertrophic scars and keloids are fibroproliferative disorders that may arise after any deep cutaneous injury caused by trauma, burns, surgery, etc. Hypertrophic scars and keloids are cosmetically problematic, and in combination with functional problems such as contractures and subjective symptoms including pruritus, these significantly affect patients’ quality of life. There have been many studies on hypertrophic scars and keloids; but the mechanisms underlying scar formation have not yet been well established, and prophylactic and treatment strategies remain unsatisfactory. In this review, the authors introduce and summarize classical concepts surrounding wound healing and review recent understandings of the biology, prevention and treatment strategies for hypertrophic scars and keloids.

Inducers of Senescence, Toxic Compounds, and Senolytics: The Multiple Faces of Nrf2-Activating Phytochemicals in Cancer Adjuvant Therapy

The reactivation of senescence in cancer and the subsequent clearance of senescent cells are suggested as therapeutic intervention in the eradication of cancer. Several natural compounds that activate Nrf2 (nuclear factor erythroid-derived 2-related factor 2) pathway, which is involved in complex cytoprotective responses, have been paradoxically shown to induce cell death or senescence in cancer. Promoting the cytoprotective Nrf2 pathway may be desirable for chemoprevention, but it might be detrimental in later stages and advanced cancers. However, senolytic activity shown by some Nrf2-activating compounds could be used to target senescent cancer cells (particularly in aged immune-depressed organisms) that escape immunosurveillance. We herein describe in vitro and in vivo effects of fifteen Nrf2-interacting natural compounds (tocotrienols, curcumin, epigallocatechin gallate, quercetin, genistein, resveratrol, silybin, phenethyl isothiocyanate, sulforaphane, triptolide, allicin, berberine, piperlongumine, fisetin, and phloretin) on cellular senescence and discuss their use in adjuvant cancer therapy. In light of available literature, it can be concluded that the meaning and the potential of adjuvant therapy with natural compounds in humans remain unclear, also taking into account the existence of few clinical trials mostly characterized by uncertain results. Further studies are needed to investigate the therapeutic potential of those compounds that display senolytic activity.

Basics of Radiation Biology When Treating Hyperproliferative Benign Diseases

For decades, low- and moderate-dose radiation therapy (RT) has been shown to exert a beneficial therapeutic effect in a multitude of non-malignant conditions including painful degenerative muscoloskeletal and hyperproliferative disorders. Dupuytren and Ledderhose diseases are benign fibroproliferative diseases of the hand/foot with fibrotic nodules and fascial cords, which determine debilitating contractures and deformities of fingers/toes, while keloids are exuberant scar formations following burn damage, surgery, and trauma. Although RT has become an established and effective option in the management of these diseases, experimental studies to illustrate cellular composites and factors involved remain to be elucidated. More recent findings, however, indicate the involvement of radiation-sensitive targets like mitotic fibroblasts/myofibroblasts as well as inflammatory cells. Radiation-related molecular mechanisms affecting these target cells include the production of free radicals to hamper proliferative activity and interference with growth factors and cytokines. Moreover, an impairment of activated immune cells involved in both myofibroblast proliferative and inflammatory processes may further contribute to the clinical effects. We here aim at briefly describing mechanisms contributing to a modulation of proliferative and inflammatory processes and to summarize current concepts of treating hyperproliferative diseases by low and moderate doses of ionizing radiation.

Keloids and Hypertrophic Scars: Pathophysiology, Classification, and Treatment

BACKGROUND

Keloid and hypertrophic scars represent an aberrant response to the wound healing process. These scars are characterized by dysregulated growth with excessive collagen formation, and can be cosmetically and functionally disruptive to patients.

OBJECTIVE

Objectives are to describe the pathophysiology of keloid and hypertrophic scar, and to compare differences with the normal wound healing process. The classification of keloids and hypertrophic scars are then discussed. Finally, various treatment options including prevention, conventional therapies, surgical therapies, and adjuvant therapies are described in detail.

MATERIALS AND METHODS

Literature review was performed identifying relevant publications pertaining to the pathophysiology, classification, and treatment of keloid and hypertrophic scars.

RESULTS

Though the pathophysiology of keloid and hypertrophic scars is not completely known, various cytokines have been implicated, including interleukin (IL)-6, IL-8, and IL-10, as well as various growth factors including transforming growth factor-beta and platelet-derived growth factor. Numerous treatments have been studied for keloid and hypertrophic scars,which include conventional therapies such as occlusive dressings, compression therapy, and steroids; surgical therapies such as excision and cryosurgery; and adjuvant and emerging therapies including radiation therapy, interferon, 5-fluorouracil, imiquimod, tacrolimus, sirolimus, bleomycin, doxorubicin, transforming growth factor-beta, epidermal growth factor, verapamil, retinoic acid, tamoxifen, botulinum toxin A, onion extract, silicone-based camouflage, hydrogel scaffold, and skin tension offloading device.

CONCLUSION

Keloid and hypertrophic scars remain a challenging condition, with potential cosmetic and functional consequences to patients. Several therapies exist which function through different mechanisms. Better understanding into the pathogenesis will allow for development of newer and more targeted therapies in the future.