Detection of serum/salivary exosomal Alix in patients with oral squamous cell carcinoma.

OBJECTIVE: Owing to variations in the exterior appearances of noncancerous diseases in the oral cavity, clinicians may have difficulty diagnosing oral squamous cell carcinoma (OSCC). Tissue biopsy is confirmatory, but invasive. Therefore, reliable tumor markers for OSCC are required. Here, exosomal Alix (exoAlix) levels were measured in serum/salivary samples from patients with OSCC and healthy controls (HCs). METHODS: Fifty-seven patients admitted to Nagoya University Hospital from 2017 through 2019 were enrolled, and serum samples (OSCC, n = 29; HC, n = 21) and/or saliva samples (OSCC, n = 23; HC, n = 20) were collected. Exosomal fractions were isolated using ultracentrifugation. ExoAlix levels were measured using enzyme-linked immunosorbent assay. RESULTS: Serum/salivary exoAlix levels were significantly higher in patients with OSCC than in HCs. Receiver operating characteristic analyses revealed that sensitivity, specificity, positive predictive value, and area under the curve were 0.345, 1.000, 1.000, and 0.685, respectively, for serum exoAlix and 0.348, 1.000, 1.000, and 0.712, respectively, for salivary exoAlix at optimal cut-off values (serum, 0.205; saliva, 0.193). All tested OSCC tissue sections (n = 21) were immuno-reactive for Alix. CONCLUSION: Serum and salivary exoAlix were identified as potential diagnostic OSCC biomarkers. Serum exoAlix was suitable for prediction of therapeutic responses.

Dosimetric impact of dental metallic crown on intensity-modulated radiotherapy and volumetric-modulated arc therapy for head and neck cancer.

Metal dental restoration materials cause dose enhancement upstream and dose disturbance downstream of the high-density inhomogeneous regions in which these materials are used. In this study, we evaluated the impact of a dental metallic crown (DMC) on intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) for head and neck cancer. Additionally, the possibility of sparing the oral mucosa from dose enhancement using an individual intraoral mouthpiece was evaluated. An experimental oral phantom was designed to verify the dosimetric impact of a DMC. We evaluated the effect on single beam, parallel opposing beam, arc beam, IMRT, and VMAT treatment plans. To evaluate the utility of a 3-mm-thick intraoral mouthpiece, the doses across the mouthpiece were measured. For single beam irradiation, the measured doses at the entrance and exit planes of the DMC were 51% higher and 21% lower than the calculated dose by the treatment planning system, respectively. The maximum dose enhancements were 22% and 46% for parallel opposing beams and the 90° arc rotation beam, respectively. For IMRT and VMAT, the measured doses adjacent to the DMC were 12.2% ± 6.3% (mean ± 1.96SD) and 12.7% ± 2.5% higher than the calculated doses, respectively. With regard to the performance of the intraoral mouthpiece for the IMRT and VMAT cases, the disagreement between measured and calculated doses at the outermost surface of the mouthpieces were -2.0%, and 2.0%, respectively. Dose enhancements caused by DMC-mediated radiation scattering occurred during IMRT and VMAT. Because it is difficult to accurately estimate the dose perturbations, careful consideration is necessary when planning head and neck cancer treatments in patients with DMCs. To spare the oral mucosa from dose enhancement, the use of an individual intraoral mouthpiece should be considered.

Factors secreted from dental pulp stem cells show multifaceted benefits for treating acute lung injury in mice.

BACKGROUND AIMS: Acute respiratory distress syndrome (ARDS) is a severe inflammatory disorder characterized by acute respiratory failure, resulting from severe, destructive lung inflammation and irreversible lung fibrosis. We evaluated the use of stem cells derived from human exfoliated deciduous teeth (SHEDs) or SHED-derived serum-free conditioned medium (SHED-CM) as treatments for bleomycin (BLM)-induced mice acute lung injury (ALI), exhibiting several pathogenic features associated with the human disease ARDS. METHODS: Mice with BLM-induced ALI with or without SHED or SHED-CM treatment were examined for weight loss and survival. The lung tissue was characterized by histological and real-time quantitative polymerase chain reaction analysis. The effects of SHED-CM on macrophage differentiation in vitro were also assessed. RESULTS: A single intravenous administration of either SHEDs or SHED-CM attenuated the lung injury and weight loss in BLM-treated mice and improved their survival rate. Similar recovery levels were seen in the SHEDs and SHED-CM treatment groups, suggesting that SHED improves ALI by paracrine mechanisms. SHED-CM contained multiple therapeutic factors involved in lung-regenerative mechanisms. Importantly, SHED-CM attenuated the BLM-induced pro-inflammatory response and generated an anti-inflammatory/tissue-regenerating environment, accompanied by the induction of anti-inflammatory M2-like lung macrophages. Furthermore, SHED-CM promoted the in vitro differentiation of bone marrow-derived macrophages into M2-like cells, which expressed high levels of Arginase1, CD206 and Ym-1. DISCUSSION: Our results suggest that SHED-secreted factors provide multifaceted therapeutic effects, including a strong M2-inducing activity, for treating BLM-induced ALI. This work may open new avenues for research on stem cell-based ARDS therapies.

Factors secreted from dental pulp stem cells show multifaceted benefits for treating experimental rheumatoid arthritis.

Rheumatoid arthritis (RA) is an autoimmune disease characterized by synovial hyperplasia and chronic inflammation, which lead to the progressive destruction of cartilage and bone in the joints. Numerous studies have reported that administrations of various types of MSCs improve arthritis symptoms in animal models, by paracrine mechanisms. However, the therapeutic effects of the secreted factors alone, without the cell graft, have been uncertain. Here, we show that a single intravenous administration of serum-free conditioned medium (CM) from human deciduous dental pulp stem cells (SHED-CM) into anti-collagen type II antibody-induced arthritis (CAIA), a mouse model of rheumatoid arthritis (RA), markedly improved the arthritis symptoms and joint destruction. The therapeutic efficacy of SHED-CM was associated with an induction of anti-inflammatory M2 macrophages in the CAIA joints and the abrogation of RANKL expression. SHED-CM specifically depleted of an M2 macrophage inducer, the secreted ectodomain of sialic acid-binding Ig-like lectin-9 (ED-Siglec-9), exhibited a reduced ability to induce M2-related gene expression and attenuate CAIA. SHED-CM also inhibited the RANKL-induced osteoclastogenesis in vitro. Collectively, our findings suggest that SHED-CM provides multifaceted therapeutic effects for treating CAIA, including the ED-Siglec-9-dependent induction of M2 macrophage polarization and inhibition of osteoclastogenesis. Thus, SHED-CM may represent a novel anti-inflammatory and reparative therapy for RA.

Dental pulp-derived stem cell conditioned medium reduces cardiac injury following ischemia-reperfusion.

Stem cells from human exfoliated deciduous teeth (SHEDs) can regenerate various tissues. We investigated the impact of SHED-conditioned medium (SHED-CM) on myocardial injury in a mouse model of ischemia-reperfusion (I/R). Wild-type (WT) mice were subjected to myocardial ischemia followed by reperfusion. SHED-CM was intravenously injected at 5 min after reperfusion. Administration of SHED-CM reduced myocardial infarct size as well as decreased apoptosis and inflammatory cytokine levels, such as TNF-α, IL-6, and IL-ß, in the myocardium following I/R. In cultured cardiac myocytes, SHED-CM significantly suppressed apoptosis under hypoxia/serum-deprivation and reduced LPS-induced expression of pro-inflammatory genes. Furthermore, anti-apoptotic action of SHED-CM was stronger than bone marrow-derived stem cell (BMSC)-CM or adipose-derived stem cell (ADSC)-CM in cardiac myocytes. SHED-CM contains a higher concentration of hepatocyte growth factor (HGF) than BMSC-CM and ADSC-CM, and neutralization of HGF attenuated the inhibitory actions of SHED-CM on apoptosis in cardiac myocytes. Finally, WT mice were intravenously treated with an HGF-depleted SHED-CM, followed by myocardial I/R. HGF depletion significantly attenuated the inhibitory actions of SHED-CM on myocardial infarct size and apoptosis after I/R. SHED-CM protects the heart from acute ischemic injury because it suppresses inflammation and apoptosis. SHED-CM could be a useful treatment option for acute myocardial infarction.

Improvement of transduction efficiency of recombinant adenovirus vector conjugated with cationic liposome for human oral squamous cell carcinoma cell lines.

Adenovirus (Ad) vectors are commonly used in gene therapy trials because of their efficiency in gene transfer. However, their use is limited by immune responses that reduce transgene expression and decrease the efficiency of repeated vector administration. In this study, the efficacy of gene transduction and the tumor-cell killing effect on four human oral (SAS, HSC-2, HSC-3, HSC-4) and one murine squamous cell carcinoma cell (SCC-7, a kind gift of Dr. M. Hiraoka, Kyoto University) lines in vitro with Ad vector conjugated with catioic liposome (Ad/SUV) was evaluated. Ad/SUV resulted in two to five-fold over higher transduction efficiency in four human and one murine cell lines in vitro than Ad vector alone. The optimal Ad-SUV ratio was determined as 10(6) pfu of Ad vector with 1 micromol SUV. Ad/SUV showed more tumor-cell killing effect than Ad vector alone. Furthermore, the shielding effects of Ad vector with Ad/SUV from neutralizing antibody were evaluated. We also found that Ad/SUV is less susceptible to inactivation by neutralizing antibodies in vitro. The efficacy of gene transduction with Ad vector was blocked more than 70% with neutralizing serum, while Ad/SUV retained approximately 50% of the control activity in vitro. On the basis of these results, the anti-tumor effect with suicide gene therapy using Ad/SUV in vivo was evaluated. Three injections of Ad/SUV showed the inhibition of tumor growth compared with control in vivo. Our results suggested that an enhanced anti-tumor effect on human oral squamous cell carcinoma would be obtained with repeated administrations of Ad/SUV.

Organ preservation with daily concurrent chemoradiotherapy using superselective intra-arterial infusion via a superficial temporal artery for T3 and T4 head and neck cancer.

PURPOSE: To evaluate the therapeutic results and rate of organ preservation in patients with advanced head and neck cancer treated with superselective intra-arterial chemotherapy via a superficial temporal artery and daily concurrent radiotherapy. METHODS AND MATERIALS: Between April 2002 and March 2006, 30 patients with T3 or T4a squamous cell carcinoma of the head and neck underwent intra-arterial chemoradiotherapy. Treatment consisted of superselective intra-arterial infusions (docetaxel, total 60 mg/m(2); cisplatin, total 150 mg/m(2)) and daily concurrent radiotherapy (total, 60 Gy) for 6 weeks. RESULTS: The median follow-up for all patients was 46.2 months (range, 10-90 months). The median follow-up for living patients was 49.7 months (range, 36-90 months). After intra-arterial chemoradiotherapy was administered, primary site complete response was achieved in 30 (100%) of 30 cases. Seven patients (23.3%) died. Using the Kaplan-Meier method, 1-year, 3-year, and 5-year survival rates were 96.7%, 83.1%, and 70.2%, respectively, while 1-year, 3-year, and 5-year local control rates were 83.3%, 79.7%, and 73.0%, respectively. Grade 3 or 4 mucositis occurred in 20 cases (66.7%). Grade 3 toxicities included dysphagia in 20 cases (66.7%), dermatitis in 6 cases (20%), nausea/vomiting in 2 cases (6.7%), and neutropenia and thrombocytopenia in 1 case (3.3%). No osteoradionecrosis of mandible and maxillary bones developed during follow-up. CONCLUSIONS: Intra-arterial chemoradiotherapy using a superficial temporal artery provided good overall survival and local control rates. This combination chemoradiotherapy approach can preserve organs and minimize functional disturbance, thus contributing to patients' quality of life.

Inverse association between toothbrushing and upper aerodigestive tract cancer risk in a Japanese population.

BACKGROUND: Oral hygiene is attracting increasing attention as a potential risk factor for cancers. To investigate the association between toothbrushing frequency and upper aerodigestive tract (UADT) cancer, the authors conducted a large-scale case-control study. METHODS: A total of 856 UADT cancer case participants and 2696 age- and sex-matched control subjects without cancer were included. Edentulous or participants with unknown frequency of toothbrushing or number of remaining teeth were excluded. Associations were assessed by odds ratios and 95% confidence intervals in logistic regression models with adjustment for potential confounders. RESULTS: Compared with toothbrushing once per day, the adjusted odds ratio for brushing twice or more was 0.82 (95% confidence interval: 0.68, 0.99) whereas that for not brushing was 1.79 (0.79, 4.05). This association was observed especially in subjects who had a history of heavy smoking or drinking. CONCLUSIONS: The authors suggest that toothbrushing could have a protective effect for UADT cancer.