Severe late dysphagia after multimodal treatment of stage III/IV laryngeal and hypopharyngeal cancer

Background

Long-term side effects after radiotherapy for organ preservation ‘could deteriorate’ the laryngeal function. This study intended to identify the incidence of severe late dysphagia following the multimodal treatment for stage III/IV laryngeal and hypopharyngeal cancer ‘to evaluate the function of larynx’.

Methods

The medical records of patients successfully treated for laryngeal and hypopharyngeal cancer with a multimodal approach, including radiotherapy, were retrospectively analyzed. ‘Functional larynx was defined as tolerable oral diet without severe late dysphagia or tracheostoma’.

Results

The study included 99 patients with a median follow-up period of 72 months. ‘Tracheostomy during the follow-up period was required in only one patient due to aspiration pneumonia, and dysphagia is the main determinant for functional larynx’. The probability of maintaining functional larynx was 63% for 10 years, when the treatment was started with radiotherapy or concurrent chemoradiotherapy. In upfront surgery (operation first and adjuvant radiotherapy/concurrent chemoradiotherapy) group, 37% of patients required total laryngectomy as primary treatment and 43% of patients could maintain laryngeal function for 10 years. And severe late dysphagia in the latter group developed mainly after laryngeal preservation surgery. The patients aged ≥65 years showed significantly higher incidence of dysphagia. Severe late dysphagia was very rare in laryngeal cancer successfully cured with radiotherapy/concurrent chemoradiotherapy (1/25, 4%); however, it gradually increased over time in hypopharyngeal cancer patients showing a statistically significant difference from laryngeal cancer patients (P = 0.040).

Conclusion

Severe late dysphagia occurred in 19.2% of patients treated for laryngeal and hypopharyngeal cancers, regardless of whether treatment started with radiotherapy/concurrent chemoradiotherapy or surgery.

Poor prognostic factors in human papillomavirus-positive head and neck cancer: who might not be candidates for de-escalation treatment?

BACKGROUND/AIMS

Since patients with human papillomavirus (HPV)-associated head and neck squamous cell carcinoma (HNSCC) have favorable outcomes after treatment, treatment de-escalation for these patients is being actively investigated. However, not all HPV-positive HNSCCs are curable, and some patients have a poor prognosis. The purpose of this study was to identify poor prognostic factors in patients with HPV-positive HNSCC.

METHODS

Patients who received a diagnosis of HNSCC and tested positive for HPV from 2000 to 2015 at a single hospital site (n = 152) were included in this retrospective analysis. HPV typing was conducted using the HPV DNA chip assay or liquid bead microarray system. Expression of p16 in the tumors was assessed by immunohistochemistry. To determine candidate factors associated with overall survival (OS), univariate and multivariable Cox regression analyses were performed.

RESULTS

A total of 152 patients with HPV-positive HNSCC were included in this study; 82.2% were male, 43.4% were current or former smokers, and 84.2% had oropharyngeal cancer. By univariate analysis, old age, performance status ≥ 1, non-oropharyngeal location, advanced T classification (T3-4), and HPV genotype 18 were significantly associated with poor OS. By multivariable analysis, performance status ≥ 1 and non-oropharyngeal location were independently associated with shorter OS (hazard ratio [HR], 4.36, p = 0.015; HR, 11.83, p = 0.002, respectively). Furthermore, HPV genotype 18 positivity was also an independent poor prognostic factor of OS (HR, 10.87, p < 0.001).

CONCLUSION

Non-oropharyngeal cancer, poor performance status, and HPV genotype 18 were independent poor prognostic factors in patients with HPV-positive HNSCC. Patients with these risk factors might not be candidates for de-escalation treatment.

Lung metastasis in adenoid cystic carcinoma of the head and neck

BACKGROUND

Distant metastasis of adenoid cystic carcinoma (ACC) is most commonly identified in the lung, but risk factors are still on debate.

METHODS

Risk factors for lung metastasis were evaluated by using Cox proportional hazards model and Kaplan-Meier curves.

RESULTS

Of 112 patients, 48% had distant metastasis; 94.4% of whom had lung metastasis. Univariable analysis revealed sublingual or minor salivary gland, tumor size ≥2.5 cm, and perineural invasion as risk factors (hazard ratio [HR]: 1.99 [1.02-3.91], 2.57 [1.19-5.58], and 2.46 [1.28-4.74], respectively), whereas size, perineural invasion, and local recurrence were risk factors in multivariable analysis (HR: 2.29 [1.05-4.96], 2.32 [1.09-4.96], and 2.68 [1.24-5.79], respectively).

CONCLUSION

Sublingual gland or minor salivary glands ACC has a higher risk of lung metastasis. If the site is not considered, the following factors increased the risk of lung metastasis; (a) size ≥2.5 cm, (b) perineural invasion, and (c) local recurrence.

Dysregulation of ectonucleotidase-mediated extracellular adenosine during postmenopausal bone loss

Adenosine and its receptors play a key role in bone homeostasis and regeneration. Extracellular adenosine is generated from CD39 and CD73 activity in the cell membrane, through conversion of adenosine triphosphate to adenosine monophosphate (AMP) and AMP to adenosine, respectively. Despite the relevance of CD39/CD73 to bone health, the roles of these enzymes in bona fide skeletal disorders remain unknown. We demonstrate that CD39/CD73 expression and extracellular adenosine levels in the bone marrow are substantially decreased in animals with osteoporotic bone loss. Knockdown of estrogen receptors ESR1 and ESR2 in primary osteoprogenitors and osteoclasts undergoing differentiation showed decreased coexpression of membrane-bound CD39 and CD73 and lower extracellular adenosine. Targeting the adenosine A2B receptor using an agonist attenuated bone loss in ovariectomized mice. Together, these findings suggest a pathological association of purine metabolism with estrogen deficiency and highlight the potential of A2B receptor as a target to treat osteoporosis.

Prognostic value of the association between MHC class I downregulation and PD-L1 upregulation in head and neck squamous cell carcinoma patients

The purpose of this study was to evaluate the prognostic impact of major histocompatibility complex (MHC) class I expression and programmed death-ligand 1 (PD-L1) expression in patients with head and neck squamous cell carcinoma (HNSCC). A total of 158 patients with HNSCC were evaluated retrospectively. The expression of MHC class I and PD-L1 was analyzed in tumor specimens using immunohistochemistry. The association between MHC class I/PD-L1 expression and clinical outcome was evaluated by Kaplan-Meier and Cox regression analyses. Among 158 patients, 103 (65.2%) showed positive PD-L1 expression, and 20 (12.7%) showed no detectable expression of MHC class I. The frequency of PD-L1 positive expression with concomitant MHC class I loss was 7.0%. In the PD-L1-positive group, MHC class I loss was associated with a significantly worse survival compared with MHC class I positivity (median overall survival 39.3 months vs. not reached; P = 0.005), whereas MHC class I status provided no prognostic impact in the PD-L1 negative group. Neither PD-L1 nor MHC class I alone showed a significant difference in overall survival. The loss of MHC class I expression in PD-L1-positive HNSCC was associated with a poor clinical outcome. This suggested that MHC class I expression status might be useful for the prognosis of tumor progression in HNSCC when combined with PD-L1 expression status. External validation with enough numbers of participants in such subgroup should be needed for validation.

Injectable basic fibroblast growth factor-loaded alginate/hyaluronic acid hydrogel for rejuvenation of geriatric larynx

Increase in the geriatric population has led to an increase in the number of elderly patients with laryngeal atrophy and dysfunction. Symptoms of voice change, dysphagia, and aspiration pneumonia negatively influence patient's health status, quality of life, and life span. Injection laryngoplasty used to treat laryngeal dysfunctions does not recover intrinsic functions of the larynx. Thus, we fabricated an injectable basic fibroblast growth factor (bFGF)-loaded alginate (ALG)/hyaluronic acid (HA) hydrogel for inducing rejuvenation of geriatric laryngeal muscles. Optimal in situ-forming bFGF-loaded ALG/HA hydrogel for injection laryngoplasty was prepared and the release profile of bFGF was analyzed. For in vivo analysis, the bFGF-loaded ALG/HA hydrogel was injected into the laryngeal muscles of 18-month-old Sprague-Dawley rats. The rejuvenation efficacy of bFGF-loaded ALG/HA hydrogel in geriatric laryngeal muscle tissues 4- and 12-weeks post-injection was evaluated by quantitative polymerase chain reaction (qPCR), histology, immune-fluorescence staining and functionality analysis. The bFGF-loaded ALG/HA hydrogel induced an increase in the expression of myogenic regulatory factor-related genes, hypertrophy of muscle fiber, proliferation of muscle satellite cells, and angiogenesis and decreased interstitial fibrosis. Administration of the bFGF-loaded ALG/HA hydrogel caused successful glottal gap closure. Thus, the bFGF-loaded ALG/HA hydrogel could be a promising candidate for laryngoplasty aimed at rejuvenating geriatric larynx. STATEMENT OF SIGNIFICANCE: In this manuscript, optimal in situ-forming bFGF-loaded ALG/HA hydrogel for injection laryngoplasty was prepared and the release profile of bFGF was analyzed. Herein, we introduced the materials and methods of injection laryngoplasty for geriatric rat experiment. In addition, we studied effects of bFGF-loaded ALG/HA hydrogel on the therapeutic rejuvenation of geriatric rat larynx. The bFGF-loaded ALG/HA hydrogel induced an increase in the expression of myogenic regulatory factor-related genes, hypertrophy of muscle fiber, proliferation of muscle satellite cells, and angiogenesis and decreased interstitial fibrosis. Furthermore, our functional analysis through the high-speed camera setup demonstrated that the administration of the bFGF-loaded ALG/HA hydrogel induced successful glottal gap closure. Thus, the bFGF-loaded ALG/HA hydrogel could be a promising candidate for injection laryngoplasty with therapeutic effects.

Dual growth factor-immobilized bioactive injection material for enhanced treatment of glottal insufficiency

With increasing demand for treatment of glottal insufficiency, several injection materials have been examined. However, biological resorption, degradation of injected materials, and the subsequent need to perform multiple injections still remain major clinical problems. In this study, we fabricated two different growth factor (GF) [single basic fibroblast growth factor (bFGF), single hepatocyte growth factor (HGF), or dual bFGF/HGF]-immobilized polycaprolactone (PCL)/Pluronic F127 microspheres. These materials were investigated for their potential use as bioactive injection laryngoplasty agents. HGF was found to be continuously released over 20 days and the bFGF was found to be continuously released over 25 days, as demonstrated by ELISA assay. Human vocal fold fibroblasts (hVFFs) showed significantly higher proliferative ability on dual GF-immobilized microspheres. GF-immobilized microspheres (bFGF, HGF, and dual GF) were injected into paralyzed vocal folds of New Zealand white rabbits. Through endoscopic observation and H&E staining, we identified that the microspheres remained localized at the injection site, resulting in constant volume augmentation of the paralyzed vocal fold without significant loss of the initial volume after 4 weeks. The expression of genes related to the extracellular matrix (ECM) in the vocal fold was upregulated by dual GF-immobilized microspheres. Furthermore, dual GF-immobilized microspheres inhibited muscle degeneration and upregulation of myogenic-related genes. In conclusion, dual GF-immobilized microspheres passively augmented the volume of the paralyzed vocal fold while actively inducing ECM synthesis at the injected vocal fold and preserving muscle tissue. Dual GF-immobilized microspheres could be a new and promising injection material for paralyzed vocal folds. STATEMENT OF SIGNIFICANCE: Limitation of prolonged augmentation of vocal fold and degeneration of vocal fold tissue still remain as major clinical problems in the treatment of vocal fold paralysis. Herein, we fabricated the polycaprolactone (PCL)/Pluronic F127 microspheres to augment volume of paralyzed vocal folds. On top of that, we additionally immobilized the growth factors (bFGF, HGF, or dual bFGF/HGF) on the surface of these microspheres. We highlight the efficacy of the dual GF-immobilized microspheres which augmented the volume of the paralyzed vocal fold passively, induced ECM synthesis actively at the injected vocal fold and preserved laryngeal muscle tissue. Our results suggest that the dual GF-immobilized microsphere could be a new promising injection material for injection laryngoplasty to treat paralyzed vocal fold.

A Phase II Study of Genexol-PM and Cisplatin as Induction Chemotherapy in Locally Advanced Head and Neck Squamous Cell Carcinoma

Lessons Learned.

Induction chemotherapy with Genexol‐PM and cisplatin demonstrated modest tumor response in locally advanced head and neck squamous cell carcinoma.

Considering favorable toxicity profiles and promising survival data, further studies on this regimen are warranted in patients with head and neck squamous cell carcinoma.

Background.

Genexol‐PM is a polymeric micellar formulation of paclitaxel without Cremophor EL. We investigated the efficacy and safety of Genexol‐PM plus cisplatin as induction chemotherapy (IC) in patients with locally advanced head and neck squamous cell carcinoma (LA‐HNSCC).

Methods.

Patients received Genexol‐PM (230 mg/m²) and cisplatin (60 mg/m²) every 3 weeks as IC. After three cycles of IC, definitive treatment of either concurrent chemoradiotherapy (CCRT) with weekly cisplatin (30 mg/m²) or surgery was performed. The primary endpoint was overall response rate (ORR) after IC.

Results.

Of 52 patients enrolled, 47 completed three cycles of IC, and the ORR was 55.8% (95% confidence interval, 42.3–69.3). Although there was one treatment‐related death, toxicity profiles to Genexol‐PM and cisplatin were generally favorable, and the most common grade 3 or 4 toxicities were neutropenia (15.4%), anorexia (7.7%), and general weakness (7.7%). Fifty‐one patients received definitive treatment (CCRT [n = 44] or radical surgery [n = 7]). The rate of complete response following CCRT was 81.8% (36/44). After a median follow‐up of 39 months, estimates of progression‐free survival (PFS) and overall survival (OS) at 3 years were 54.3% and 71.3%, respectively.

Conclusion.

IC with Genexol‐PM and cisplatin demonstrated modest tumor response with well‐tolerated toxicity profiles for patients with LA‐HNSCC.

Guidelines for the Surgical Management of Oral Cancer: Korean Society of Thyroid-Head and Neck Surgery

Korean Society of Thyroid-Head and Neck Surgery appointed a Task Force to provide guidance on the implementation of a surgical treatment of oral cancer. MEDLINE databases were searched for articles on subjects related to “surgical management of oral cancer” published in English. Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. The quality of evidence was rated with use RoBANS (Risk of Bias Assessment Tool for Nonrandomized Studies) and AMSTAR (A Measurement Tool to Assess the Methodological Quality of Systematic Reviews). Evidence-based recommendations for practice were ranked according to the American College of Physicians grading system. Additional directives are provided as expert opinions and Delphi questionnaire when insufficient evidence existed. The Committee developed 68 evidence-based recommendations in 34 categories intended to assist clinicians and patients and counselors, and health policy-makers. Proper surgical treatment selection for oral cancer, which is directed by patient- and subsite-specific factors, remains the greatest predictor of successful treatment outcomes. These guidelines are intended for use in conjunction with the individual patient’s treatment goals.

Long-term oncological and functional outcomes of induction chemotherapy followed by (chemo)radiotherapy vs definitive chemoradiotherapy vs surgery-based therapy in locally advanced stage III/IV hypopharyngeal cancer: Multicenter review of 266 cases

OBJECTIVE

The aim of this study was to evaluate the treatment outcomes for stage III/IV locally advanced hypopharyngeal squamous cell carcinoma (SCC), comparing induction chemotherapy followed by (chemo)radiotherapy (ICT), definitive chemoradiotherapy (CRT) and surgery-based therapy (SRT).

SUBJECTS AND METHODS

Two hundred sixty-six patients with stage III/IV locally advanced hypopharyngeal squamous cell carcinoma (SCC) who underwent ICT (n = 74), CRT (n = 53) or SRT (n = 139) from 1997 through 2014 at the Seoul National University Hospital (n = 127) and the Hallym University Medical Center (n = 139) were enrolled in the study. All surgical procedures in the SRT group were performed by a single surgeon to eliminate surgeon bias.

RESULTS

The 5-year disease-free survival (DFS) and overall survival (OS) of all patients (n = 266) were 59.4% and 44%, respectively. The 5-year DFS rates after salvage treatment were 52.7% for ICT, 52.8% for CRT and 65.5% for SRT (p = 0.194). The OS rates were 44.6% for ICT, 39.6% for CRT and 45.3% for SRT group (p = 0.106). The salvage rates were 12.5% for ICT, 15.6% for CRT and 3.8% for SRT group. The final laryngeal preservation rate was significantly lower in the SRT group (44.6%) than in the ICT (71.6%) or CRT (71.7%) groups. All major postoperative complications were significantly higher in the salvage surgery group.

CONCLUSION

Treatment outcomes in the ICT and CRT groups were comparable to that of the SRT group for stage III/IV hypopharyngeal SCC. However, the relatively low chance of cure and high risk of complications should be taken into account when considering salvage surgery.

Characterization of the biomechanical properties of canine trachea using a customized 3D-printed apparatus

OBJECTIVES

The canine trachea is considered to be an excellent preclinical model for tracheal research due to its similar mechanical and dimensional characteristics to the human trachea. However, normative biomechanical properties have yet to be defined and it is one of the main reasons tracheal reconstruction has not succeeded in animal models at large scale. Variation and inaccurate measurement due to a lack of proper apparatus for mechanical tests further prevent determination of normative mechanical data of the trachea. The goal of this study was to overcome these shortcomings by designing the measuring apparatus using 3D-printing technology. Using this apparatus, we determined the normative biomechanical properties of the canine trachea.

METHODS

Whole tracheas were obtained from thirteen mongrel dogs. Biomechanical measurements were performed to determine the radial compressive strength and tensile strength of the intact trachea, and the elastic modulus of the tracheal cartilage.

RESULTS

Structural parameter data indicated the canine trachea to have inner-diameters similar to those of the human trachea and other widely used animal models. The compressive strength was 4.24N while the tensile strength was 29.96N. The elastic modulus of the cartilage portion of the trachea was 1.58N without showing a significant difference in value based on the location of the trachea.

CONCLUSIONS

This study delineates a comprehensive and foundational characterization of the biomechanical properties of both the intact and cartilage portion of the canine trachea. The parameters were in agreement with those of the human trachea, confirming the canine trachea to be an excellent preclinical model for tracheal research.

Bioglass-Incorporated Methacrylated Gelatin Cryogel for Regeneration of Bone Defects

Cryogels have recently gained interest in the field of tissue engineering as they inherently possess an interconnected macroporous structure. Considered to be suitable for scaffold cryogel fabrication, methacrylated gelatin (GelMA) is a modified form of gelatin valued for its ability to retain cell adhesion site. Bioglass nanoparticles have also attracted attention in the field due to their osteoinductive and osteoconductive behavior. Here, we prepare methacrylated gelatin cryogel with varying concentration of bioglass nanoparticles to study its potential for bone regeneration. We demonstrate that an increase in bioglass concentration in cryogel leads to improved mechanical property and augmented osteogenic differentiation of mesenchymal cells during in vitro testing. Furthermore, in vivo testing in mice cranial defect model shows that highest concentration of bioglass nanoparticles (2.5 w/w %) incorporated in GelMA cryogel induces the most bone formation compared to the other tested groups, as studied by micro-CT and histology. The in vitro and in vivo results highlight the potential of bioglass nanoparticles incorporated in GelMA cryogel for bone regeneration.

Effects of excessive fibrin deposit and polylactide adhesion barrier on wound healing in thyroidectomy murine wound model

BACKGROUND

We hypothesize that excessive fibrin formation and inflammation induced by antiadhesive material, SurgiWrap (SW), would have an adverse effect on wound healing. It was evaluated by a thyroidectomy murine wound model.

METHODS

Excessive fibrin formation was induced by isthmectomy without hemostasis. Rats were allocated into isthmectomy with SurgiWrap (I+SW+), I+SW-, I-SW+, I-SW-, and isthmectomy after electrocautery for hemostasis (I+C+SW-). The SWs were placed on the superficial and visceral layers for gross and microscopic evaluation.

RESULTS

Microscopic examination showed collagen deposition occurred in the I-SW- sham group and at a higher level in I+C+SW-. The collagen deposition decreased in groups without SW with time but increased in groups with SW. Use of SW produced more inflammation and more collagen deposition. The I+SW + group developed the largest area of collagen deposition at 4 weeks and more collagen deposition than the I-SW + group.

CONCLUSION

The SW induced more collagen deposition increasing with time. The collagen deposition produced by SW was worsened by excessive fibrin formation and inflammation.

A computational simulation study to determine the biomechanical influence of posterior condylar offset and tibial slope in cruciate retaining total knee arthroplasty

Objectives

Posterior condylar offset (PCO) and posterior tibial slope (PTS) are critical factors in total knee arthroplasty (TKA). A computational simulation was performed to evaluate the biomechanical effect of PCO and PTS on cruciate retaining TKA.

Methods

We generated a subject-specific computational model followed by the development of ± 1 mm, ± 2 mm and ± 3 mm PCO models in the posterior direction, and -3°, 0°, 3° and 6° PTS models with each of the PCO models. Using a validated finite element (FE) model, we investigated the influence of the changes in PCO and PTS on the contact stress in the patellar button and the forces on the posterior cruciate ligament (PCL), patellar tendon and quadriceps muscles under the deep knee-bend loading conditions.

Results

Contact stress on the patellar button increased and decreased as PCO translated to the anterior and posterior directions, respectively. In addition, contact stress on the patellar button decreased as PTS increased. These trends were consistent in the FE models with altered PCO. Higher quadriceps muscle and patellar tendon force are required as PCO translated in the anterior direction with an equivalent flexion angle. However, as PTS increased, quadriceps muscle and patellar tendon force reduced in each PCO condition. The forces exerted on the PCL increased as PCO translated to the posterior direction and decreased as PTS increased.

Conclusion

The change in PCO alternatively provided positive and negative biomechanical effects, but it led to a reduction in a negative biomechanical effect as PTS increased.

Cite this article: K-T. Kang, Y-G. Koh, J. Son, O-R. Kwon, J-S. Lee, S. K. Kwon. A computational simulation study to determine the biomechanical influence of posterior condylar offset and tibial slope in cruciate retaining total knee arthroplasty. Bone Joint Res 2018;7:69–78. DOI: 10.1302/2046-3758.71.BJR-2017-0143.R1.

Prevention of polydimethylsiloxane microsphere migration using a mussel-inspired polydopamine coating for potential application in injection therapy

The use of injectable bulking agents is a feasible alternative procedure for conventional surgical therapy. In this study, poly(dimethylsiloxane) (PDMS) microspheres coated with polydopamine (PDA) were developed as a potential injection agent to prevent migration in vocal fold. Uniform PDMS microspheres are fabricated using a simple fluidic device and then coated with PDA. Cell attachment test reveals that the PDA-coated PDMS (PDA-PDMS) substrate favors cell adhesion and attachment. The injected PDA-PDMS microspheres persist without migration on reconstructed axial CT images, whereas, pristine PDMS locally migrates over a period of 12 weeks. The gross appearance of the implants retrieved at 4, 8, 12 and 34 weeks indicates that the PDA-PDMS group maintained their original position without significant migration until 34 weeks after injection. By contrast, there is diffuse local migration of the pristine PDMS group from 4 weeks after injection. The PDA-coated PDMS microspheres can potentially be used as easily injectable, non-absorbable filler without migration.

Serial Analysis of Tracheal Restenosis After 3D-Printed Scaffold Implantation: Recruited Inflammatory Cells and Associated Tissue Changes

Tracheal restenosis is a major obstacle to successful tracheal replacement, and remains the greatest challenge in tracheal regeneration. However, there have been no detailed investigations of restenosis. The present study was performed to analyze the serial changes in recruited inflammatory cells and associated histological changes after tracheal scaffold implantation. Asymmetrically porous scaffolds, which successfully prevented tracheal stenosis in a partial trachea defect model, designed with a tubular shape by electrospinning and reinforced by 3D-printing to reconstruct 2-cm circumferential tracheal defect. Serial rigid bronchoscopy, micro-computed tomography, and histology [H&E, Masson's Trichrome, IHC against α-smooth muscle actin (α-SMA)] were performed 1, 4, and 8 weeks after transplantation. Progressive stenosis developed especially at the site of anastomosis. Neutrophils were the main inflammatory cells recruited in the early stage, while macrophage infiltration increased with time. Recruitment of fibroblasts peaked at 4 weeks and deposition of α-SMA increased from 4 weeks and was maintained through 8 weeks. During the first 8 weeks post-transplantation, neutrophils and macrophages played significant roles in restenosis of the trachea. Antagonists to these would be ideal targets to reduce restenosis and thus play a pivotal role in successful tracheal regeneration.

Changes in programmed death-ligand 1 expression during cisplatin treatment in patients with head and neck squamous cell carcinoma

Programmed death-ligand 1 (PD-L1) expression is regarded as a predictive marker for anti-PD-1/PD-L1 therapy. The purpose of study was to explore the changes in PD-L1 expression in head and neck squamous cell carcinoma (HNSCC) during treatment. Paired HNSCC tissues prior to and after cisplatin-based treatment were evaluated to determine PD-L1 protein expression by immunohistochemistry. Among the 35 HNSCC patient samples, PD-L1 expression status changed after treatment in 37.1% (13/35) of samples. Among the 13 patients whose baseline PD-L1 was negative, PD-L1 expression was increased in 9 cases (69.2%) and remained negative in 4 cases (30.8%, P = 0.003). Patients exposed to cisplatin generally showed PD-L1 up-regulation (83.3%, P = 0.037) compared to those not exposed to cisplatin (57.1%, P = 0.072). To validate these findings in vitro, changes in PD-L1 expression in HNSCC cell lines (Detroit-562, PCI-13, SNU-1041, SNU-1066, SNU-1076, and FaDu) were analyzed by western blotting and flow cytometry after treatment with cisplatin and interferon-gamma. In HNSCC cell lines, PD-L1 expression was significantly up-regulated after cisplatin, along with phosphor-MAPK/ERK kinase up-regulation. In conclusion, PD-L1 expression in HNSCC may be altered during cisplatin treatment, activating the MAPK/ERK kinase pathway.

Treatment of chemically induced oral ulcer using adipose-derived mesenchymal stem cell sheet

BACKGROUND

This study investigated the effects of mesenchymal stem cell (MSC) sheet transplantation on healing of chemically induced oral ulceration in a rabbit animal model.

METHODS

Oral mucosal ulcers were induced by topical application of filter paper soaked with 70% acetic acid to the anterior gingiva and buccal mucosa of 12 New Zealand white rabbits. The animals were randomly assigned to two groups: with (treatment group, n = 6) or without (control group, n = 6) cell sheets applied to ulcers. Gross findings were sequentially evaluated, and histologic examination was performed on day 7.

RESULTS

Based on gross inspection, ulceration resolved before day 5 in the treatment group; however, in the control group, healing was incomplete on day 7. In the treatment group, the total area of the ulcer decreased significantly from day 2 to day 5 (P < 0.001) and from day 5 to day 7 (P = 0.020), whereas the area decreased significantly from day 5 to day 7 in the control group (P < 0.001). Histologic and immunofluorescence examination revealed full-thickness mucosa healing and complete basal cell coverage in the treatment group; in contrast, only partial healing was observed on day 7 in the control group.

CONCLUSIONS

Cell sheet technology using MSC can be an alternative treatment for oral ulcerations in that it can decrease healing time without invasive properties.

Human Adipose Tissue Derived Extracellular Matrix and Methylcellulose Hydrogels Augments and Regenerates the Paralyzed Vocal Fold

Vocal fold paralysis results from various etiologies and can induce voice changes, swallowing complications, and issues with aspiration. Vocal fold paralysis is typically managed using injection laryngoplasty with fat or synthetic polymers. Injection with autologous fat has shown excellent biocompatibility. However, it has several disadvantages such as unpredictable resorption rate, morbidities associated with liposuction procedure which has to be done in operating room under general anesthesia. Human adipose-derived extracellular matrix (ECM) grafts have been reported to form new adipose tissue and have greater biostability than autologous fat graft. Here, we present an injectable hydrogel that is constructed from adipose tissue derived soluble extracellular matrix (sECM) and methylcellulose (MC) for use in vocal fold augmentation. Human sECM derived from adipose tissue was extracted using two major steps—ECM was isolated from human adipose tissue and was subsequently solubilized. Injectable sECM/MC hydrogels were prepared by blending of sECM and MC. Sustained vocal fold augmentation and symmetric vocal fold vibration were accomplished by the sECM/MC hydrogel in paralyzed vocal fold which were confirmed by laryngoscope, histology and a high-speed imaging system. There were increased number of collagen fibers and fatty granules at the injection site without significant inflammation or fibrosis. Overall, these results indicate that the sECM/MC hydrogel can enhance vocal function in paralyzed vocal folds without early resorption and has potential as a promising material for injection laryngoplasty for stable vocal fold augmentation which can overcome the shortcomings of autologous fat such as unpredictable duration and morbidity associated with the fat harvest.