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The global prevalence of oral squamous cell carcinoma (OSCC) has been increasing. OSCC at the advanced stage tends to resist conventional treatment and causes local recurrence and distant metastasis, resulting in poor prognosis. Therefore, detecting this cancer at an early stage and performing early intervention are important. Promising biomarkers to detect OSCC have yet to be established; however, microRNAs (miRNAs/miRs) serve a crucial role in OSCC tumorigenesis and may be potential biomarkers. In the present case report, the availability of salivary miRNAs as a therapeutic and prognostic marker for patients with OSCC was assessed. The patient was a 33-year-old woman who was diagnosed with advanced OSCC of the tongue, and their miRNA profile isolated from a saliva sample at each clinical course was evaluated. Microarray analysis of the salivary samples revealed changes in the levels of four miRNAs (hsa-miR-6798-5p, miR-6803-5p, miR-6805-5p and miR-6845-5p) in accordance with the clinical course. Neoadjuvant chemotherapy and surgical procedure decreased the levels, whereas the levels increased when the patient was diagnosed with lung metastasis. Furthermore, tongue and lung metastatic lesion specimens exhibited expression of the vascular endothelial growth factor receptor-2, which is regulated by the four miRNAs. Accordingly, the present report proposed that salivary miRNAs could be a therapeutic and prognostic biomarker for OSCC., Competing Interests: The authors declare that they have no competing interests., (Copyright: © 2024 Kimura et al.)

Background: The activity level of alkaline phosphatase, a zinc-requiring enzyme in the serum, is used to indicate zinc nutritional status; however, it does not correlate with serum zinc levels or subjective symptoms of taste disorder in many cases. Hence, this study focused on the total activity of alkaline phosphatase, a zinc-requiring enzyme. The total alkaline phosphatasa activity level in the saliva was measured before and after zinc supplementation, and the results were compared with serum zinc levels., Case Presentation: This study included patients with hypozincemia, specifically a patient with zinc-deficient taste disorder (patient 1: a 69-year-old Japanese woman) and a patient with glossodynia with zinc deficiency (patient 2: an 82-year-old Japanese woman). Saliva samples were collected, and blood tests were performed before and after zinc supplementation. Subjective symptoms and serum zinc levels were simultaneously evaluated. Zinc supplementation was performed using zinc acetate hydrate or Polaprezinc., Conclusions: Total alkaline phosphatase activity levels were found to be associated with serum zinc levels and subjective symptoms. A further study with a higher number of patients is necessary to confirm whether total alkaline phosphatase activity levels more accurately reflect the amounts of zinc in the body than serum zinc levels., (© 2024. The Author(s).)

Objective: This study aimed to elucidate the difference in virulence of Candida albicans derived from oral candidiasis and non-oral candidiasis patients, and its genotype differences in Hokkaido to obtain a clue of a platform to develop new approaches for diagnosis and treatment., Design: C. albicans strains were collected from patients who visited the Hokkaido University Hospital Dental Center. Each strain was examined to i) identify the Candida albicans genotype by PCR, ii) measure the strain's extracellular secretory enzyme activity, iii) determine the strain's ability to induce the production of interleukin-8, and iv) determine the strain's ability to induce cell death., Results: Certain virulence-related protease activities and cytotoxicity were higher in strains derived from patients with oral candidiasis compared with strains derived from patients without oral candidiasis. This is the first report on genotypes and the virulence-related activities, such as some protease secretion, IL-8 induction and cytotoxicity of C. albicans in Hokkaido., Conclusions: The virulence-related activities of the fungal strain may influence the pathogenesis of oral candidiasis, such as production of secreted aspartyl protease and cytotoxicity. In addition, C. albicans genotype C may be important for pathogenicity in Hokkaido, because the ratio of genotype C was increased in strains derived from oral candidiasis patients., Competing Interests: Declaration of Competing Interest This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Background/purpose: Delayed healing of the extraction socket is not uncommon when tooth extraction is performed on patients taking prednisolone. This study aimed to identify specific dosage of prednisolone and factors associated with delayed healing of the extraction socket in patients taking prednisolone., Materials and Methods: This single-center retrospective study included 80 patients who underwent tooth extraction under local anesthesia and were taking prednisolone orally. Patients were divided into the nondelayed healing group ( n  = 50) and delayed healing group ( n  = 30), and their background and dosage of prednisolone were compared., Results: The dosage of prednisolone was significantly higher in the delayed healing group than in the nondelayed healing group. A receiver operating characteristics curve analysis resulted in moderate accuracy when the cutoff value was set at 8.0, with 67% sensitivity, 76% specificity, and 0.765 area under the curve. The multivariate logistic regression analysis revealed that prednisolone dosage >8.0 mg/day (odds ratio [OR], 10.8; 95% confidence interval [CI], 2.79-41.6) and osteosclerotic changes beyond the alveolar bone around the tooth to be extracted (OR, 10.3; 95% CI, 2.81-37.8) in X-ray imaging had significant effects on delayed healing., Conclusion: The results of this study suggested that delayed healing following tooth extractions in patients taking prednisolone was related to a dosage of 8.0 mg/day or higher and osteosclerotic changes., Competing Interests: The authors have no conflicts of interest relevant to this article., (© 2022 Association for Dental Sciences of the Republic of China. Publishing services by Elsevier B.V.)

The principle of microscopic reversibility says that, in equilibrium, two-time cross-correlations are symmetric under the exchange of observables. Thus, the asymmetry of cross-correlations is a fundamental, measurable, and often-used statistical signature of deviation from equilibrium. Here we find a simple and universal inequality that bounds the magnitude of asymmetry by the cycle affinity, i.e., the strength of thermodynamic driving. Our result applies to a large class of systems and all state observables, and it suggests a fundamental thermodynamic cost for various nonequilibrium functions quantified by the asymmetry. It also provides a powerful tool to infer affinity from measured cross-correlations, in a different and complementary way to the thermodynamic uncertainty relations. As an application, we prove a thermodynamic bound on the coherence of noisy oscillations, which was previously conjectured by Barato and Seifert [Phys. Rev. E 95, 062409 (2017)PRESCM2470-004510.1103/PhysRevE.95.062409]. We also derive a thermodynamic bound on directed information flow in a biochemical signal transduction model.

We construct an information-geometric structure for chemical thermodynamics, applicable to a wide range of chemical reaction systems including nonideal and open systems. For this purpose, we explicitly construct dual affine coordinate systems, which completely designate an information-geometric structure, using the extent of reactions and the affinities of reactions as coordinates on a linearly constrained space of amounts of substances. The resulting structure induces a metric and a divergence (a function of two distributions of amounts), both expressed with chemical potentials. These quantities have been partially known for ideal-dilute solutions, but their extensions for nonideal solutions and the complete underlying structure are novel. The constructed geometry is a generalization of dual affine coordinates for stochastic thermodynamics. For example, the metric and the divergence are generalizations of the Fisher information and the Kullback-Leibler divergence. As an application, we identify the chemical-thermodynamic analog of the Hatano-Sasa excess entropy production using our divergence.

Background: Ethyl loflazepate (EL) is a benzodiazepine derivative that has been reported to activate the gustatory cortex. Our department routinely uses EL as a first-line treatment for idiopathic and psychogenic taste disorders, although little has been reported in the literature with respect to patient outcomes, so we conducted a retrospective study examining its safety and efficacy., Methods: Between 2008 and 2020, 49 patients (14 males and 35 females; mean age, 62.1 years) were diagnosed with taste disorders and received EL as their only treatment for > 14 days. Severity of taste disorder was evaluated using the paper disc method by Sakai et al., and treatment efficacy was evaluated using the Visual Analog Scale, wherein patients gave subjective ratings for their symptoms (reductions by > 50% after administration of EL for 4 weeks were defined as improvements)., Results: Results showed that the improvement rates for patients with idiopathic and psychogenic taste disorders were 55 and 70%, respectively. Additionally, the majority (78%) improved within 2 weeks, and side effects were mild (seven cases with drowsiness and one case with dizziness)., Conclusions: We conclude that EL is an appropriate first-line medication for patients with idiopathic and psychogenic taste disorders., (© 2022. The Author(s).)

Tumor blood vessels play important roles in tumor progression and metastasis. Targeting tumor endothelial cells (TECs) is one of the strategies for cancer therapy. We previously reported that biglycan, a small leucine-rich proteoglycan, is highly expressed in TECs. TECs utilize biglycan in an autocrine manner for migration and angiogenesis. Furthermore, TEC-derived biglycan stimulates tumor cell migration in a paracrine manner leading to tumor cell intravasation and metastasis. In this study, we explored the therapeutic effect of biglycan inhibition in the TECs of renal cell carcinoma using an in vivo siRNA delivery system known as a multifunctional envelope-type nanodevice (MEND), which contains a unique pH-sensitive cationic lipid. To specifically deliver MEND into TECs, we incorporated cyclo(Arg-Gly-Asp-D-Phe-Lys) (cRGD) into MEND because α V β 3 integrin, a receptor for cRGD, is selective and highly expressed in TECs. We developed RGD-MEND-encapsulating siRNA against biglycan. First, we confirmed that MEND was delivered into OS-RC-2 tumor-derived TECs and induced in vitro RNAi-mediated gene silencing. MEND was then injected intravenously into OS-RC-2 tumor-bearing mice. Flow cytometry analysis demonstrated that MEND was specifically delivered into TECs. Quantitative RT-PCR indicated that biglycan was knocked down by biglycan siRNA-containing MEND. Finally, we analyzed the therapeutic effect of biglycan silencing by MEND in TECs. Tumor growth was inhibited by biglycan siRNA-containing MEND. Tumor microenvironmental factors such as fibrosis were also normalized using biglycan inhibition in TECs. Biglycan in TECs can be a novel target for cancer treatment., (© 2022 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

Background: Basal cell carcinoma (BCC) is the most common cancer worldwide. Most of BCCs can be detected in the early stages and are generally well controlled with local resection. Despite the high incidence of BCC, metastasis is rarely observed. Metastatic BCCs generally have an aggressive phenotype and are refractory to conventional treatment., Case Presentation: We describe a rare case of BCC in which a series of local relapses culminated in metastasis into the oral cavity 10 years after the first diagnosis of cutaneous BCC. We performed surgical resection and postoperative radiotherapy in this patient; 11 months after the final course of radiotherapy, the BCC remains stable, and the patient continues to be monitored regularly., Conclusions: Because metastatic BCC is refractory to current treatment and difficult to control, his treatment history and the pathohistological features of BCC had to be considered in posttreatment planning., (© 2022. The Author(s).)

Background: Burning mouth syndrome (BMS) is a chronic condition characterized by pain in the oral cavity. Kampo medicine is a traditional Japanese medical system that has its roots partly in ancient Chinese medicine. The purpose of this study is to evaluate the efficacy of rikkosan-a traditional Japanese herbal medicine (Kampo)-in the treatment of primary BMS., Main Body: A single-center retrospective study was conducted in 32 patients who were diagnosed with primary BMS and treated with rikkosan alone through gargling (2.5 g rikkosan dissolved in 50 mL hot water) three times daily. Patients were asked to evaluate their pain using a numerical rating scale (NRS) at first visit and after 1 month. One patient had stomatitis as a side effect after gargling with rikkosan, however, no side effects were observed in other patients. Overall NRS scores decreased significantly between the first visit (7.6 ± 2.7) and the 1-month visit (5.6 ± 2.8)., Conclusions: Rikkosan may be an effective treatment for primary BMS., (© 2021. The Author(s).)

Development of quantitative analysis software has enabled application of several standardised uptake values (SUV) for bone analysis in single photon emission computed tomography (SPECT). The present retrospective study aimed to develop a reliable method of monitoring bone inflammatory activity in antiresorptive agent-related osteonecrosis of the jaw (ARONJ) using SPECT quantitative analysis software. Fifteen ARONJ patients underwent SPECT before and after anti-inflammatory therapy. We calculated the mean maximum SUV (SUVmax) of the bilateral cranial bones using quantitative analysis software and used this as the control [C]. We attempted to adjust the SUVmax of the lesion [L] as follows: adjusted SUVmax (aSUVmax) = [L] - [C]. The optimum threshold to calculate the metabolic bone volume (MBV) (cm 3 ) was [C] + 3. The threshold values obtained for each case were input to calculate MBV at each osteomyelitis site. Retrospectively, we compared aSUVmax and MBV of each patient's ARONJ before and after anti-inflammatory therapy. The patients' high aSUVmax or large MBV of the ARONJ reduced rapidly, reflecting individual clinical findings after treatment. Application of SPECT quantitative analysis software to monitor bone inflammatory activity in ARONJ could improve the prognosis-deciding abilities of clinicians and enable them to treat ARONJ effectively.

Medication-related osteonecrosis of jaws (MRONJ) is one of the most complicated inflammatory conditions in oral and maxillofacial region. It is very difficult to correctly evaluate the degree and extent of necrosis and infection. This refractory osteonecrosis often needs extended surgery, leading to impaired quality-of-life. We have performed hyperbaric oxygen therapy (HBO) combined with conservative surgery for advanced cases. We have appraised the value of FDG-PET and 3-phase bone scintigraphy in the diagnosis and management of this condition. MRONJ showed significantly higher SUV max on FDG-PET than the others. Although the 3 phase pool bone images did not change significantly, perfusion and static bone image as well as PET showed remarkable response to HBO for MRONJ. SUV max after HBO was significantly lower than those of before HBO. These preliminary results indicate that FDG-PET is useful for monitoring the effect of HBO for MRONJ.

Background: Mucous membrane pemphigoid (MMP) is a rare chronic autoimmune subepithelial blistering disorder, targeting multiple basement membrane zone (BMZ) proteins including collagen XVII (COL17). Circulating autoantibodies of MMP are often undetected due to their lower titers. The oral mucosa is a valuable substrate for the detection of autoantibodies in MMP patients. However, obtaining normal human oral mucosa is more difficult than obtaining normal human skin. We established immortalized normal human oral mucosal keratinocytes (OMKs) and performed immunoblotting using immortalized OMK lysate for detecting autoantigens in MMP., Methods: Immortalized OMKs were generated from primary OMKs using E6/E7 proteins of HPV. We compared the protein expression levels of major BMZ proteins between primary OMKs and immortalized OMKs. We performed immunoblotting to detect autoantigens using cell lysates from immortalized OMKs in 30 MMP patients., Results: There were no significant differences between primary OMKs and immortalized OMKs in terms of protein expression levels of the BMZ proteins, including COL17, laminin 332, integrin α6/β4, collagen VII, and collagen IV. Cell lysates of immortalized OMKs effectively identified MMP autoantigens in 60% (18/30) of MMP sera. We found an interesting case of MMP whose autoantibodies preferentially reacted to the 120-kD protein that is an ectodomain of COL17., Conclusion: We demonstrated that a cell lysate of immortalized OMKs is a reliable substrate for the detection of MMP autoantigens. This newly developed immunoblotting analysis method promises to contribute to the diagnosis of MMP., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Tumour hypoxia can be detected by 18 F-fluoromisonidazole positron emission tomography (FMISO-PET). Few studies have assessed the relationships of new PET parameters, including hypoxic volume (HV), metabolic tumour volume (MTV), and total lesion glycolysis (TLG), with 5-year survival of patients treated surgically for oral squamous cell carcinoma (OSCC). This study evaluated the relationships between these PET parameters and 5-year survival in OSCC patients. Twenty-three patients (age 42-84 years; 15 male, eight female) with OSCC underwent FMISO- and 18 F-fluoro-2-deoxyglucose (FDG)-PET computed tomography before surgery. All of them underwent radical surgery and were followed up for more than 5 years. The FDG-PET maximum standardized uptake value (SUV max ), HV, MTV, and TLG were measured. The ability of PET parameters to predict disease-free survival (DFS) and loco-regional recurrence (LR) was evaluated using receiver operating characteristic curve analysis. During the follow-up period, five of the 23 patients (22%) died and six (26%) experienced LR. Although FDG-PET SUV max was not significantly associated with DFS or LR, HV correlated significantly with both DFS and LR. TLG, but not MTV, was significantly associated with DFS; however neither MTV nor TLG was related significantly to LR. In conclusion, tumour HV may predict outcomes in patients with OSCC., (Copyright © 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

We report a case of osteonecrosis of the jaw (ONJ) associated with denosumab therapy in a 62-year-old female patient being treated for bone metastases from breast cancer. Upon initial presentation at the Department of Oral Medicine, Hokkaido University Hospital, the patient's mandibular molar teeth were extracted because of severe periodontal disease. Two months later, epithelialization of the sockets was observed and treatment with anti-resorptive drugs was started for bone metastases. One year after tooth extraction, bone exposure in the right lower first molar region was observed, and stage 2 medication-related ONJ (MRONJ) was diagnosed. Up to this time, the patient had received zoledronic acid twice and denosumab 22 times. Denosumab was discontinued by the oncologist, and oral antibiotics with rinsing of the exposed bone area were prescribed. By 36 weeks after discontinuation of denosumab, a sequestrum in the posterior part of the mandible was naturally shed, and the site was healed. Bisphosphonate is deposited in bones, whereas denosumab functions extracellularly and circulates in the blood. The effect of denosumab on bone remodeling is reversed shortly after the drug has been discontinued.

Tumor blood vessels play an important role in tumor progression and metastasis. We previously reported that tumor endothelial cells (TEC) exhibit several altered phenotypes compared with normal endothelial cells (NEC). For example, TEC have chromosomal abnormalities and are resistant to several anticancer drugs. Furthermore, TEC contain stem cell-like populations with high aldehyde dehydrogenase (ALDH) activity (ALDH high TEC). ALDH high TEC have proangiogenic properties compared with ALDH low TEC. However, the association between ALDH high TEC and drug resistance remains unclear. In the present study, we found that ALDH mRNA expression and activity were higher in both human and mouse TEC than in NEC. Human NEC:human microvascular endothelial cells (HMVEC) were treated with tumor-conditioned medium (tumor CM). The ALDH high population increased along with upregulation of stem-related genes such as multidrug resistance 1, CD90, ALP, and Oct-4. Tumor CM also induced sphere-forming ability in HMVEC. Platelet-derived growth factor (PDGF)-A in tumor CM was shown to induce ALDH expression in HMVEC. Finally, ALDH high TEC were resistant to fluorouracil (5-FU) in vitro and in vivo. ALDH high TEC showed a higher grade of aneuploidy compared with that in ALDH low TEC. These results suggested that tumor-secreting factor increases ALDH high TEC populations that are resistant to 5-FU. Therefore, ALDH high TEC in tumor blood vessels might be an important target to overcome or prevent drug resistance., (© 2017 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

Objective: Hypoxia is a common feature and prognostic factor in cancer. 18 F-fluoromisonidazole (FMISO) positron emission tomography (PET) can detect tumor hypoxia noninvasively. The aim of this study was to assess the correlations between FMISO-PET and 18 F-fluorodexyglucose (FDG)-PET parameters with cell proliferation and hypoxia in patients with oral squamous cell carcinoma (OSCC)., Study Design: Twenty-three preoperative patients with OSCC were included. The tumor/muscle ratio (TMR) of FMISO-PET, the maximum standardized uptake values (SUV max ) of FDG-PET, metabolic tumor volume, and total lesion glycolysis were measured. Ki-67 and hypoxia-inducible factor-1α (HIF-1α) expression was immunohistochemically evaluated., Results: FMISO TMR (P = .003) and FDG SUV max (P = .04) were significantly higher in patients with high expression of Ki-67 compared with those with low expression of Ki-67. FMISO TMR (P = .006) and FDG SUV max (P = .01) were also significantly higher in patients with HIF-1α expression than in those without HIF-1α expression. Metabolic tumor volume was not significantly related to either Ki-67 or HIF-1α expression. Multivariate analysis showed that FMISO TMR was independently predictive of Ki-67 (P = .002; odds ratio 31.1) and HIF-1α (P = .049; odds ratio 10.5) expression., Conclusions: FMISO-PET showed significant relationships with Ki-67 and HIF-1α expression, which are key features of cell proliferation and hypoxia in OSCC., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Objectives: The aim of the present study was to evaluate the effectiveness of platelet-rich fibrin (PRF) as a wound-healing accelerator in patients undergoing oral bisphosphonate therapy and requiring tooth extractions., Materials and Methods: A total of 102 patients were divided into a PRF group and control group. The patients received oral bisphosphonate therapy for osteoporosis for an average of 32 months. Blood was collected and PRF was introduced into the socket of the PRF group only. Monitoring of mucosal healing was conducted for 3 months in both groups, and radiographic evaluation in the sockets was performed in the PRF group. Delayed recovery was defined as exposed bone and vulnerable granulation tissue without epithelization after 4 weeks and resolving by 8 weeks., Results: There were no intraoperative complications, and none of the patients exhibited onset of medication-related osteonecrosis of the jaw (MRONJ). Delayed recovery was observed in 9 out of 73 control patients (12%), whereas 29 PRF patients exhibited complete epithelialization of the socket within 1 month. The prevalence of delayed recovery was significantly higher in the control group than the PRF group (P < 0.05). Multivariate logistic regression analysis revealed that risk factors and use of PRF were independent significant factors to relate to delayed recovery (P = 0.02)., Conclusions: Early epithelization was confirmed in all PRF patients. Thus, PRF may reduce the risk of delayed recovery in patients undergoing oral bisphosphonate therapy., Clinical Relevance: PRF may be useful in preventing MRONJ in patients receiving oral bisphosphonate (BP).

Tumor progression is dependent on tumor angiogenesis. We previously reported that the phenotype of tumor endothelial cells (TECs) is distinct from normal endothelial cells (NECs). Herein, we conducted a pathway analysis using a public TEC microarray database and identified several putative TEC-specific miRNAs. We found that miR-145 expression was upregulated in TECs and that miR-145 enhanced cell adhesion and anoikis resistance and upregulated Bcl-2 and Bcl-xl via ERK1/2 in human microvascular endothelial cells. These findings suggested that miR-145 is involved in the acquisition of the TEC phenotype, partially. Therefore, miR-145 and its target genes may be molecular targets for anti-angiogenic therapy., (© The Authors 2017. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.)

Reactive oxygen species (ROS) are unstable molecules that activate oxidative stress. Because of the insufficient blood flow in tumors, the tumor microenvironment is often exposed to hypoxic condition and nutrient deprivation, which induces ROS accumulation. We isolated tumor endothelial cells (TECs) and found that they have various abnormalities, although the underlying mechanisms are not fully understood. Here we showed that ROS were accumulated in tumor blood vessels and ROS enhanced TEC migration with upregulation of several angiogenesis related gene expressions. It was also demonstrated that these genes were upregulated by regulation of Nuclear factor erythroid 2-related factor 2 (NRF2). Among these genes, we focused on Biglycan, a small leucine-rich proteoglycan. Inhibition of Toll-like receptors 2 and 4, known BIGLYCAN (BGN) receptors, cancelled the TEC motility stimulated by ROS. ROS inhibited NRF2 expression in TECs but not in NECs, and NRF2 inhibited phosphorylation of SMAD2/3, which activates transcription of BGN. These results indicated that ROS-induced BGN caused the pro-angiogenic phenotype in TECs via NRF2 dysregulation.

Aim: We evaluated the prognostic value of vasohibin-1 (VASH1) expression in head and neck squamous cell carcinoma., Materials and Methods: Immunohistochemistry for VASH1 and cluster of differentiation 34 (CD34) was performed on 61 head and neck squamous cell carcinoma specimens. The association between VASH1 expression in the tumour and clinical outcomes was analyzed statistically., Results: VASH1 staining in normal tissue adjacent to cancerous tissue was negative, whereas it was positive in tumour blood vessels and AE1/AE3 and Ki67-positive tumour cells. Therefore, we examined the association between VASH1 expression in the tumour and clinical outcomes. Patients with high VASH1 expression in tumour had significantly shorter disease-free survival and more frequently had lymph node recurrence than those with low VASH1 expression., Conclusion: These results suggest that VASH1 expression is associated with tumour progression and may be useful as a prognostic marker of head and neck squamous cell carcinoma., (Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Changes in facial bones may represent a manifestation of systemic disease. Dentists play an important role in the early detection of these manifestations of complex systemic diseases. A case of unusual maxillary mixed (osteoblastic and osteolytic) lesions as an initial manifestation of childhood acute myeloid leukemia (AML) is presented. A 12-year-old male patient was referred to the Department of Oral Medicine complaining of severe swelling in the right buccal region. 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) showed enhanced FDG uptake in the right maxillary sinus. In addition, PET maximum intensity projection image showed diffused FDG uptake in the entire bone marrow. Bone marrow aspiration was performed on the lumbar vertebra, and fluorescence in situ hybridization (FISH) demonstrated AML. The patient was diagnosed with AML (M5a) and treated with chemotherapy by the pediatric department. Six months later, the patient achieved complete remission. After chemotherapy, the disappearance of the osteoblastic and osteolytic lesion and 18F-FDG accumulation were confirmed by PET/CT. Dentists should be familiar with oral manifestations of leukemia because early detection of oral lesions would increase the life span of the patients and reduce the severity of complications.

It has been described that tumor progression has many similarities to inflammation and wound healing in terms of the signaling processes involved. Among biological responses, angiogenesis, which is necessary for tumor progression and metastasis, is a common hallmark; therefore, tumor blood vessels have been considered as important therapeutic targets in anticancer therapy. We focused on pentraxin 3 (PTX3), which is a marker of cancer-related inflammation, but we found no reports on its expression and function in tumor blood vessels. Here we showed that PTX3 is expressed in mouse and human tumor blood vessels based on immunohistochemical analysis. We found that PTX3 is upregulated in primary mouse and human tumor endothelial cells compared to normal endothelial cells. We also showed that PTX3 plays an important role in the proliferation of the tumor endothelial cells. These results suggest that PTX3 is an important target for antiangiogenic therapy., (© 2016 Japanese Society of Pathology and John Wiley & Sons Australia, Ltd.)

Objectives: Candida infections are frequently encountered fungal infections in the oral mucosa. This study aimed to evaluate the effect of eliminating Candida spp. on stimulated whole salivary flow rate (SWS) in patients with oral candidiasis., Subjects and Methods: This study involved 66 patients with oral candidiasis. Fifty-two consecutive patients, successfully treated by antifungal therapy, were available to examine the effect of elimination of oral Candida spp. on SWS (success group); the 14 patients who tested positive for Candida after therapy were retrospectively included (control group). SWS were used to measure saliva production. Moreover, tongue pain and xerostomia were evaluated using visual analog score (VAS)., Results: By eliminating oral Candida spp., SWS significantly increased in the success group after antifungal therapy [SWS: mean value 0.89±0.51ml/min (median 0.82ml/min: 0.15-2.14) to mean value 1.16±0.58ml/min (median 1.05ml/min: 0.2-2.93), P<0.001]. Furthermore, VAS scores for subjective tongue pain and xerostomia were significantly decreased compared with those before therapy in the success group [xerostomia: mean value 52.5±28.8 (median 53: 9-100) to 24.2±1.6 (median 17: 0-70), tongue pain: mean value 52.6±27.2 (median 56: 1-93) to 15.3±18.0 (median 9: 0-62). P<0.001]. There was no significant difference in SWS, subjective tongue pain, or xerostomia in the control group after antifungal therapy. [SWS: mean value 1.08±0.83ml/min (median 0.69ml/min: 0.2-2.7) to 0.98±0.59ml/min (median 0.8ml/min: 0.45-2.5), P=0.65], [xerostomia: mean value 62.8±5.3 (median 62: 28-70) to 64.0±8.8 (median 64: 56-73), P=0.58, tongue pain: mean value 64.3±18.6 (median 67: 31-87) to 58.4±20.0 (median 8: 20-78), respectively; P=0.24] CONCLUSION: Our study demonstrated that SWS may increase by eliminating oral Candida spp. in patients with oral candidiasis., (Copyright © 2016. Published by Elsevier Ltd.)

Tumour blood vessels are gateways for distant metastasis. Recent studies have revealed that tumour endothelial cells (TECs) demonstrate distinct phenotypes from their normal counterparts. We have demonstrated that features of TECs are different depending on tumour malignancy, suggesting that TECs communicate with surrounding tumour cells. However, the contribution of TECs to metastasis has not been elucidated. Here, we show that TECs actively promote tumour metastasis through a bidirectional interaction between tumour cells and TECs. Co-implantation of TECs isolated from highly metastatic tumours accelerated lung metastases of low metastatic tumours. Biglycan, a small leucine-rich repeat proteoglycan secreted from TECs, activated tumour cell migration via nuclear factor-κB and extracellular signal-regulated kinase 1/2. Biglycan expression was upregulated by DNA demethylation in TECs. Collectively, our results demonstrate that TECs are altered in their microenvironment and, in turn, instigate tumour cells to metastasize, which is a novel mechanism for tumour metastasis.

Only a few reports on the level of progression of extracapsular spread (ECS) have been published. The aim of this study was to evaluate the efficacy of the level of progression of ECS in identifying those patients with oral squamous cell carcinoma (OSCC) at a high risk of recurrence who would benefit most from the intensification of adjuvant therapy. The level of progression of ECS for cervical lymph node metastasis in OSCC was divided into three types (A-C), and their relationships with patient prognosis were examined. ECS was observed in 87 of 441 patients with OSCC. The recurrence rate in patients with type C, which was defined as macroscopic tumour invasion into perinodal fat or muscle tissue, was high (69.8%), with 13 cases of death due to distant metastasis. The 3-year disease-specific survival rate for patients with type C was 49.0% and these patients also had a significantly poorer prognosis (P<0.01). The results of the multivariate analysis suggested that the prognosis of ECS in OSCC patients was associated with the level of progression of ECS, especially type C (P<0.01). Overall, the results of this study suggest that the level of progression of ECS is a useful prognostic factor in OSCC patients., (Copyright © 2015 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

We reported that tumor endothelial cells (TECs) differ from normal endothelial cells (NECs) in many aspects, such as gene expression profiles. Although CXCR7 is reportedly highly expressed in blood vessels of several tumors, its function in TECs is still unknown. To investigate this role, we isolated TECs from mouse tumor A375SM xenografts, and compared them with NECs from normal mouse dermis. After confirming CXCR7 upregulation in TECs, we analyzed its function using CXCR7 siRNA and CXCR7 inhibitor; CCX771. CXCR7 siRNA and CCX771 inhibited migration, tube formation and resistance to serum starvation in TECs but not in NECs. ERK1/2 phosphorylation was inhibited by CXCR7 knockdown in TECs. These results suggest that CXCR7 promotes angiogenesis in TECs via ERK1/2 phosphorylation. Using ELISA, we also detected CXCL12, a ligand of CXCR7, in conditioned medium from TECs, but not from NECs. CXCL12 neutralizing antibody significantly inhibited TEC random motility. VEGF stimulation upregulated CXCR7 expression in NECs, implying that VEGF mediates CXCR7 expression in endothelial cells. A CXCR7 inhibitor, CCX771 also inhibited tumor growth, lung metastasis and tumor angiogenesis in vivo. Taken together, the CXCL12-CXCR7 autocrine loop affects TEC proangiogenic properties, and could be the basis for an antiangiogenic therapy that specifically targets tumor blood vessels rather than normal vessels., (© 2015 UICC.)

Objective: Sequential postoperative salivary interleukin-6 (IL-6) concentrations were examined in patients with oral squamous cell carcinoma (OSCC) who had early or late locoregional recurrences or those who did not., Study Design: Twenty-seven consecutive patients with OSCC were originally included in the study. All patients underwent radical surgery. Four saliva samples were collected before (periods I and II) and after (periods III and IV) surgery, and IL-6 concentrations were measured., Results: Although postoperative (period III: at the time of discharge) salivary IL-6 level was significantly higher in patients with early locoregional recurrence (P = .02) than in those without, no such relationships were observed for preoperative IL-6 concentrations (periods I and II). Postoperative (period IV: 24 months after surgery) IL-6 level was significantly higher in patients with late locoregional recurrence (P = .03) than in those without, but no such relationships were observed for IL-6 concentrations in periods I, II, and III., Conclusions: Sequential postoperative salivary IL-6 concentration may be a useful marker for diagnosis of early and late locoregional recurrence in OSCC., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Osteonecrosis of the jaw (ONJ) is associated with the use of bisphosphonates (BPs), denosumab, and antiangiogenic drugs; however, the pathophysiology of medication-related ONJ (MRONJ) remains unknown. Recent advances in therapies for diseases that affect bone remodeling have led to the development of agents that inhibit the receptor activator of nuclear factor-kappa B ligand (RANKL). One such inhibitor is denosumab, a highly specific, fully human immunoglobulin G2 monoclonal antibody against RANKL. We report a case of ONJ that developed following dental extraction in a patient treated for metastatic colorectal cancer with denosumab. At the first medical examination at our hospital, her clinical presentation was indistinguishable from stage 2 MRONJ, classified according to the 2014 American Academy of Oral Medicine position paper. Discontinuation of denosumab was directed by her oncologist, and we prescribed oral antibiotics and irrigated the exposed area of bone. Seven months after denosumab cessation, the sequestrum of the anterior part of the mandible was naturally shed and the site was healed. Denosumab and BPs have significantly different mechanisms of action. The effects of denosumab on bone turnover are more rapid and reversible than those of BPs. Discontinuation of denosumab may be effective in the management of denosumab-related ONJ, depending on the primary tumor control.

Tumor angiogenesis plays an important role in tumor progression and metastasis. Tumor endothelial cells (TECs) are a therapeutic target of antiangiogenic chemotherapy that was recently developed and is currently being investigated in the clinic with promising results. Low-dose chemotherapy, which is the long-term administration of relatively low doses of chemotherapeutic agents, has been proposed for targeting tumor angiogenesis in various types of cancers. Although the efficacy of low-dose chemotherapy has been confirmed in several clinical models, some studies show insufficient therapeutic effect for malignant cancers. As a possible mechanism of the treatment failure, it has been considered that tumor cells may acquire resistance to this therapy. However, drug resistance by TECs may also be due to another mechanism for resistance of tumor cells to low-dose chemotherapy. We reported elsewhere that TECs were resistant to the anticancer drug paclitaxel, which is a mitotic inhibitor, concomitant with P-glycoprotein up-regulation. Verapamil, a P-glycoprotein inhibitor, abrogated TEC resistance in vitro. Herein, we demonstrated that verapamil coadministration enhanced the effects of low-dose paclitaxel concomitant with inhibiting tumor angiogenesis in a preclinical in vivo mouse melanoma xenograft model. Furthermore, verapamil coadministration reduced lung metastasis. These results suggest that inhibiting P-glycoprotein in TECs may be a novel strategy for low-dose chemotherapy targeting TECs., (Copyright © 2015 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)

Tumor blood vessels play an important role in tumor progression and metastasis. It has been reported that tumor endothelial cells (TECs) exhibit highly angiogenic phenotypes compared with those of normal endothelial cells (NECs). TECs show higher proliferative and migratory abilities than those NECs, together with upregulation of vascular endothelial growth factor (VEGF) and VEGF receptor 2 (VEGFR2). Furthermore, compared with NECs, stem cell markers such as Sca-1, CD90, and multidrug resistance 1 are upregulated in TECs, suggesting that stem-like cells exist in tumor blood vessels. In this study, to reveal the biological role of stem-like TECs, we analyzed expression of the stem cell marker aldehyde dehydrogenase (ALDH) in TECs and characterized ALDHhigh TECs. TECs and NECs were isolated from melanoma-xenografted nude mice and normal dermis, respectively. ALDH mRNA expression and activity were higher in TECs than those in NECs. Next, ALDHhigh/low TECs were isolated by fluorescence-activated cell sorting to compare their characteristics. Compared with ALDHlow TECs, ALDHhigh TECs formed more tubes on Matrigel-coated plates and sustained the tubular networks longer. Furthermore, VEGFR2 expression was higher in ALDHhigh TECs than that in ALDHlow TECs. In addition, ALDH was expressed in the tumor blood vessels of in vivo mouse models of melanoma and oral carcinoma, but not in normal blood vessels. These findings indicate that ALDHhigh TECs exhibit an angiogenic phenotype. Stem-like TECs may have an essential role in tumor angiogenesis.

Recent studies have reported that stromal cells contribute to tumor progression. We previously demonstrated that tumor endothelial cells (TEC) characteristics were different from those of normal endothelial cells (NEC). Furthermore, we performed gene profile analysis in TEC and NEC, revealing that suprabasin (SBSN) was upregulated in TEC compared with NEC. However, its role in TEC is still unknown. Here we showed that SBSN expression was higher in isolated human and mouse TEC than in NEC. SBSN knockdown inhibited the migration and tube formation ability of TEC. We also showed that the AKT pathway was a downstream factor of SBSN. These findings suggest that SBSN is involved in the angiogenic potential of TEC and may be a novel TEC marker., (© 2014 The Authors. Cancer Science published by Wiley Publishing Asia Pty Ltd on behalf of Japanese Cancer Association.)

The specific delivery of a gene to liver sinusoidal endothelial cells (LSEC) could become a useful strategy for treating various liver diseases associated with such cells. We previously reported that the accumulation of KLGR peptide modified liposomes through liver sinusoidal blood vessels was enhanced after an intravenous administration. Here, we report on an attempt to develop an LSEC targeted nanocarrier system to deliver siRNA for the successful knockdown of LSEC specific gene expression. The system involved the development of a multifunctional envelop-type nano device (MEND) modified with the KLGR peptide for siRNA delivery targeting LSEC. Our developed carrier successfully lowered specific gene expression in LSEC. An in vivo study showed that at a lower density of ligand at the surface of the MEND resulted in the highest knockdown of gene expression in LSEC. This is the first report of the successful delivery of siRNA to LSECs. Further experiments suggest that not only a higher endosomal escape efficiency into the cytosol but also the uptake mechanism as a function of ligand density are two important factors to be considered for targeting LSEC., (Copyright © 2014 Elsevier B.V. All rights reserved.)

The identification of a specific biomarker involves the development of new clinical diagnostic tools, and an in-depth understanding of the disease at the molecular level. When new blood vessels form in tumor cells, endothelial cell production is induced, a process that plays a key role in disease progression and metastasis to distinct organs for solid tumor types. The present study reports on the identification of a new biomarker on primary cultured mouse tumor endothelial cells (mTECs) using our recently developed high-affinity DNA aptamer AraHH001 (Kd = 43 nmol/L) assisted proteomics approach. We applied a strategy involving aptamer-facilitated biomarker discovery. Biotin-tagged AraHH001 was incubated with lysates of mTECs and the aptamer-proteins were then conjugated with streptavidin magnetic beads. Finally, the bound proteins were separated by sodiumdodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) with silver staining. We identified troponin T via matrix assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry, the molecular target of aptamer AraHH001, and its presence was confirmed by measuring mRNA, protein levels, western blot, immunostaining, a gel shift assay of AraHH001 with troponin T. We first report here on the discovery of troponin T on mTECs, a promising and interesting diagnostic tool in the development of antiangiogenic therapy techniques the involves the targeting of the tumor vasculature., (© 2014 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

The objective of this study was to construct our recently developed aptamer-modified targeted liposome nano-carrier (Apt-PEG-LPs) system to target primary cultured mouse tumor endothelial cells (mTEC), both in vitro and in vivo. We first synthesized an aptamer-polyethylene glycol 2000-distearoyl phosphoethanolamine (Apt-PEG2000-DSPE). The conjugation of the Apt-PEG2000-DSPE was confirmed by MALDI-TOF mass spectroscopy. A lipid hydration method was used to prepare Apt-PEG-LPs, in which the outer surface of the PEG-spacer was decorated with the aptamer. Apt-PEG-LPs were significantly taken up by mTECs. Cellular uptake capacity was observed both quantitatively and qualitatively using spectrofluorometry, and confocal laser scanning microscopy (CLSM), respectively. In examining the extent of localization of aptamer-modified liposomes that entered the cells, approximately 39% of the Apt-PEG-LPs were not co-localized with lysotracker, indicating that they had escaped from endosomes. The uptake route involved a receptor mediated pathway, followed by clathrin mediated endocytosis. This Apt-PEG-LP was also applied for in vivo research whether this system could target tumor endothelial cells. Apt-PEG-LP and PEG5000-DSPE modified Apt-PEG-LP (Apt/PEG5000-LP) were investigated by human renal cell carcinoma (OS-RC-2 cells) inoculating mice using CLSM. Apt-PEG-LP and Apt/PEG5000-LP showed higher accumulation on tumor vasculature compared to PEG-LP and the co-localization efficacy of Apt-PEG-LP and Apt/PEG5000-LP on TEC were quantified 16% and 25% respectively, which was also better than PEG-LP (3%). The findings suggest that this system is considerable promise for targeting tumor endothelial cells to deliver drugs or genes in vitro and in vivo., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Targeting tumor angiogenesis is an established strategy for cancer therapy. Because angiogenesis is not limited to pathological conditions such as cancer, molecular markers that can distinguish between physiological and pathological angiogenesis are required to develop more effective and safer approaches for cancer treatment. To identify such molecules, we determined the gene expression profiles of murine tumor endothelial cells (mTEC) and murine normal endothelial cells using DNA microarray analysis followed by quantitative reverse transcription-polymerase chain reaction analysis. We identified 131 genes that were differentially upregulated in mTEC. Functional analysis using siRNA-mediated gene silencing revealed five novel tumor endothelial cell markers that were involved in the proliferation or migration of mTEC. The expression of DEF6 and TMEM176B was upregulated in tumor vessels of human renal cell carcinoma specimens, suggesting that they are potential targets for antiangiogenic intervention for renal cell carcinoma. Comparative gene expression analysis revealed molecular differences between tumor endothelial cells and normal endothelial cells and identified novel tumor endothelial cell markers that may be exploited to target tumor angiogenesis for cancer treatment., (© 2014 The Authors. Cancer Science published by Wiley Publishing Asia Pty Ltd on behalf of Japanese Cancer Association.)

Angiogenesis is one of crucial processes associated with tumor growth and development, and consequently a prime target for cancer therapy. Although tumor endothelial cells (TECs) play a key role in pathological angiogenesis, investigating phenotypical changes in neovessels when a gene expression in TEC is suppressed is a difficult task. Small interfering RNA (siRNA) represents a potential agent due to its ability to silence a gene of interest. We previously developed a system for in vivo siRNA delivery to cancer cells that involves a liposomal-delivery system, a MEND that contains a unique pH-sensitive cationic lipid, YSK05 (YSK-MEND). In the present study, we report on the development of a system that permits the delivery of siRNA to TECs by combining the YSK-MEND and a ligand that is specific to TECs. Cyclo(Arg-Gly-Asp-D-Phe-Lys) (cRGD) is a well-known ligand to αVβ3 integrin, which is selectively expressed at high levels in TECs. We incorporated cRGD into the YSK-MEND (RGD-MEND) to achieve an efficient gene silencing in TECs. Quantitative RT-PCR and the 5' rapid amplification of cDNA ends PCR indicated that the intravenous injection of RGD-MEND at a dose of 4.0mg/kg induced a significant RNAi-mediated gene reduction in TEC but not in endothelial cells of other organs. Finally, we evaluated the therapeutic potency of the RGD-MEND encapsulating siRNA against vascular endothelial growth factor receptor 2. A substantial delay in tumor growth was observed after three sequential RGD-MEND injections on alternate days. In conclusion, the RGD-MEND represents a new approach for the characterization of TECs and for us in anti-angiogenic therapy., (© 2013.)

We describe herein the development of a high affinity and specific DNA aptamer as a new ligand for use in liposomal nanoparticles to target cultured mouse tumor endothelial cells (mTECs). Active targeted nanotechnology based drug delivery systems are currently of great interest, due to their potential for reducing side effects and facilitating the delivery of cytotoxic drugs or genes in a site specific manner. In this study, we report on a promising aptamer candidate AraHH036 that shows selective binding towards mTECs. The aptamer does not bind to normal cells, normal endothelial cells or tumor cells. Therefore, we synthesized an aptamer-polyethylene glycol (PEG) lipid conjugate and prepared aptamer based liposomes (ALPs) by the standard lipid hydration method. First, we quantified the higher capacity of ALPs to internalize into mTECs by incubating ALPs containing 1 mol%, 5 mol% and 10 mol% aptamer of total lipids and compared the results to those for unmodified PEGylated liposomes (PLPs). A confocal laser scanning microscope (CLSM) uptake study indicated that the ALPs were taken up more efficiently than PLPs. The measured Kd value of the ALPs was 142 nM. An intracellular trafficking study confirmed that most of the rhodamine labeled ALPs were taken up and co-localized with the green lysotracker, thus confirming that they were located in lysosomes. Finally, using an aptamer based proteomics approach, the molecular target protein of the aptamer was identified as heat shock protein 70 (HSP70). The results suggest that these ALPs offer promise as a new carrier molecule for delivering anti-angiogenesis drugs to tumor vasculature.

There is much evidence that hypoxia in the tumor microenvironment enhances tumor progression. In an earlier study, we reported abnormal phenotypes of tumor-associated endothelial cells such as those resistant to chemotherapy and chromosomal instability. Here we investigated the role of hypoxia in the acquisition of chromosomal abnormalities in endothelial cells. Tumor-associated endothelial cells isolated from human tumor xenografts showed chromosomal abnormalities, >30% of which were aneuploidy. Aneuploidy of the tumor-associated endothelial cells was also shown by simultaneous in-situ hybridization for chromosome 17 and by immunohistochemistry with anti-CD31 antibody for endothelial staining. The aneuploid cells were surrounded by a pimonidazole-positive area, indicating hypoxia. Human microvascular endothelial cells expressed hypoxia-inducible factor 1 and vascular endothelial growth factor A in response to either hypoxia or hypoxia-reoxygenation, and in these conditions, they acquired aneuploidy in 7 days. Induction of aneuploidy was inhibited by either inhibition of vascular endothelial growth factor signaling with vascular endothelial growth factor receptor 2 inhibitor or by inhibition of reactive oxygen species by N-acetyl-L-cysteine. These results indicate that hypoxia induces chromosomal abnormalities in endothelial cells through the induction of reactive oxygen species and excess signaling of vascular endothelial growth factor in the tumor microenvironment.

Liver dysfunction is associated with a variety of liver diseases, including viral or alcoholic hepatitis, fibrosis, cirrhosis, and portal hypertension. A targeted drug delivery system would be very useful in the treatment of these diseases. We herein describe the development of a system comprised of a new peptide-lipid conjugate for the efficient delivery of molecules to LEC. The RLTRKRGLK sequence (3359-3367), which mediates the association of LDL with arterial CSPG and an LDL receptor, was utilized as a ligand for achieving this goal. The peptide modified PEG-LPs (RLTR-PEG-LPs) were efficiently taken up by primary liver endothelial cells (liver ECs) and other types of cells. In vivo biodistribution and confocal microscopy analysis showed that RLTR-PEG-LPs became widely accumulated in LECs within a short time. Distribution of RLTR-PEG-LPs was greatly reduced with a pretreatment of unlabeled RLTR-PEG-LPs, not cationic LPs, indicating that the sequence is important for LECs. The findings indicate that a reverse sequence of RLTR (KLGR) modified PEG-LPs (KLGR-PEG-LP) did the same pattern compared with RLTR-PEG-LPs, suggesting that the RKR or RXXR sequence might be essential for LECs targeting. Collectively RLTR-PEG-LPs and KLGR-PEG-LPs have the potential for delivering drugs to LECs., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Tumor blood vessels play important roles in tumor progression and metastasis. Thus, targeting tumor blood vessels is an important strategy for cancer therapy. Tumor endothelial cells (TECs) are the main targets of anti-angiogenic therapy. Although tumor blood vessels generally sprout from pre-existing vessels and have been thought to be genetically normal, they display a markedly abnormal phenotype, including morphological changes. The degree of angiogenesis is determined by the balance between the positive and negative regulating molecules that are released by tumor and host cells in the microenvironment. Reportedly, tumor blood vessels are heterogeneous with TECs differing from normal endothelial cells (in contrast to the conventional view). We recently compared characteristics of different TECs isolated from highly and low metastatic tumors. We found TECs from highly metastatic tumors had more proangiogenic phenotypes than those from low metastatic tumors. Elucidating the variety of TEC phenotypes and identifying TEC molecular signatures should lead to more complete understanding of the mechanisms of tumor progression, discovery of new therapeutic targets, and development of biomarkers. This review considers current studies on TEC heterogeneity and discusses the therapeutic implications of these findings., (© 2013 Japanese Cancer Association.)

Background: Molecules that are highly expressed in tumour endothelial cells (TECs) may be candidates for specifically targeting TECs. Using DNA microarray analysis, we found that the lysyl oxidase (LOX) gene was upregulated in TECs compared with its expression in normal endothelial cells (NECs). LOX is an enzyme that enhances invasion and metastasis of tumour cells. However, there are no reports on the function of LOX in isolated TECs., Methods: TECs and NECs were isolated to investigate LOX function in TECs. LOX inhibition of in vivo tumour growth was also assessed using β-aminopropionitrile (BAPN)., Results: LOX expression was higher in TECs than in NECs. LOX knockdown inhibited cell migration and tube formation by TECs, which was associated with decreased phosphorylation of focal adhesion kinase (Tyr 397). Immunostaining showed high LOX expression in human tumour vessels in vivo. Tumour angiogenesis and micrometastasis were inhibited by BAPN in an in vivo tumour model., Conclusion: LOX may be a TEC marker and a possible therapeutic target for novel antiangiogenic therapy.

Fluorescent and luminescent tools are commonly used to study the dynamics of cancer progression and metastases in real-time. Fluorophores have become essential tools to study biological events. However, few can sustain fluorescence long enough during long-term studies. In the present study, we focused on a series of new amphiphilic fluorophores known as POLARIC™, which emit strong fluorescence in lipid bilayers and can be readily modified using the Suzuki-Miyaura cross-coupling reaction. Appropriate chemical modifications of substituent groups can improve target-site specificity, reduce cytotoxicity and prolong emission. Therefore, in contrast to conventional fluorescent probes, these fluorophores show promise for long-term monitoring of biological processes. In the present study, we conducted long-term observations of tumor growth and metastasis using a POLARIC derivative as a novel fluorescent probe. For this purpose, we studied the metastatic melanoma cell line A375-SM, which proliferates at a high rate. We compared the characteristics of the POLARIC probe with the commercially available fluorescent dye PKH26 and fluorescent protein mRFP1. A375-SM cells were labeled with these fluorescent probes and orthotopically implanted into nude mice. The fluorescence emitted by POLARIC was detected more than five weeks after implantation without causing detectable harmful effects on tumor growth. By contrast, fluorescence of cells labeled with PKH26 could not be detected at this same time. Furthermore, POLARIC-, but not PKH26-labeled cells, were also detected in lung metastases. These results indicate that labeling cells with POLARIC fluorophores can significantly extend the time course of in vivo studies on tumor cell growth.

Dysfunctional sinusoidal liver endothelial cells (LECs) are associated with liver diseases, such as liver fibrosis, cirrhosis, and portal hypertension. Because of this, gene therapy targeted to LECs would be a useful and productive strategy for directly treating these diseases at the level of genes. Here, we report on the development of a transgene vector that specifically targets LECs. The vector is a liposome-based gene vector coated with hyaluronic acid (HA). HA is a natural ligand for LECs and confers desirable properties on particles, rendering them biodegradable, biocompatible, and nonimmunogenic. In this study, we constructed HA-modified carriers, and evaluated cellular uptake and transfection activity using cultured LECs from KSN nude mice (KSN-LECs). Cellular uptake analyses showed that KSN-LECs recognized the HA-modified carriers more effectively than skin endothelial cells. The transfection assay indicated that the efficient gene expression in KSN-LECs, using the HA-modified carriers, required an adequate lipid composition and a functional device to control intracellular trafficking. This finding contributes to our overall knowledge of transgene expression targeted to LECs., (Copyright © 2013 Wiley Periodicals, Inc.)

Size of the liposomes (LPs) specially governs its biodistribution. In this study, LPs were developed with controlled sizes, where variation in LP size dictates the ligand-receptor interaction, cellular internalization and its distribution within the tumor microenvironment. The therapeutic efficacies of doxorubicin (DOX)-loaded RGD modified small size (~100 nm in diameter, dnm) and large size (~300 dnm) PEGylated LPs (RGD-PEG-LPs) were compared to that of Doxil (a clinically used DOX-loaded PEG-LP, ~100 dnm) in DOX resistant OSRC-2 (Renal cell carcinoma, RCC) tumor xenografts. Doxil, which accumulated in tumor tissue via the enhanced permeability and retention (EPR) effect, failed to suppress tumor growth. Small size RGD-PEG-LP, that targets the tumor endothelial cells (TECs) and extravasates to tumor cells, failed to provide anti-tumor effect. Large size RGD-PEG-LP preferentially targets the TECs via minimization of the EPR effect, and significantly reduced the tumor growth, which was exerted through its strong anti-angiogenic activity on the tumor vasculature rather than having a direct effect on DOX resistant RCC. The prepared large size RGD-PEG-LP that targets the TECs via interacting with Integrin αvβ3, is a potentially effective and alternate therapeutic strategy for the treatment of DOX resistant tumor cells by utilizing DOX, in cases where Doxil is ineffective., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Tumour growth is dependent on angiogenesis, and tumour blood vessels are recognized as an important target for cancer therapy. Tumour endothelial cells (TECs) are the main targets of anti-angiogenic therapy. Unlike the traditionally held view, some TECs may be genetically abnormal and might acquire drug resistance. Therefore, we investigated the drug resistance of TECs and the mechanism by which it is acquired. TECs show resistance to paclitaxel through greater mRNA expression of multidrug resistance 1, which encodes P-glycoprotein, as compared with normal endothelial cells. We found that high levels of vascular endothelial growth factor in tumour-conditioned medium may be responsible for upregulated P-glycoprotein expression. This is a novel mechanism for the acquisition of drug resistance by TECs in a tumour microenvironment. This review focuses on the possibility that TECs can acquire drug resistance.

Tumor angiogenesis is necessary for tumor progression and metastasis; therefore, tumor blood vessels are potential therapeutic targets in anticancer therapy. We previously reported that tumor endothelial cells (TECs) exhibit different phenotypes compared with normal endothelial cells (NECs), and microarray analyses of mouse TECs and NECs have shown that several genes are upregulated in TECs compared with NECs. Among these genes, the expression levels of prostaglandin F receptor (PTGFR) mRNA, which encodes the prostaglandin F receptor (FP), were higher in TECs than in NECs. It has been reported that FP and its ligand, prostaglandin F(2α) , are involved in tumor angiogenesis. However, there have been no reports of the expression of PTGFR in the tumor vessels of renal cell carcinoma (RCC). Thus, we isolated human TECs (hTECs) from RCCs. The expression levels of PTGFR mRNA were also upregulated in hTECs. In addition, immunostaining showed that the PTGFR was expressed in human tumor blood vessels in vivo. These findings suggested that PTGFR is a novel TEC marker and that it may be a novel target for antiangiogenic therapy for RCC., (© 2013 The Authors. Pathology International © 2013 Japanese Society of Pathology and Wiley Publishing Asia Pty Ltd.)

Anti-angiogenic therapy is a potential chemotherapeutic strategy for the treatment of drug resistant cancers. However, a method for delivering such drugs to tumor endothelial cells remains to be a major impediment to the success of anti-angiogenesis therapy. We designed liposomes (LPs) with controlled diameter of around 300 nm, and modified them with a specific ligand and a cell penetrating peptide (CPP) (a dual-ligand LP) for targeting CD13-expressing neovasculature in a renal cell carcinoma (RCC). We modified the LPs with an NGR motif peptide on the top of poly(ethylene glycol) and tetra-arginine (R4) on the surface of the liposome membrane as a specific and CPP ligand, respectively. The large size prevented extravasation of the dual-ligand LP, which allowed it to associate with target vasculature. While a single modification with either the specific or CPP ligand showed no increase in targetability, the dual-ligand enhanced the amount of delivered liposomes after systemic administration to OS-RC-2 xenograft mice. The anti-tumor activity of a dual-ligand LP encapsulating doxorubicin was evaluated and the results were compared with Doxil, which is clinically used to target tumor cells. Even though Doxil showed no anti-tumor activity, the dual-ligand LP suppressed tumor growth because the disruption of tumor vessels was efficiently induced. The comparison showed that tumor endothelial cells (TECs) were more sensitive to doxorubicin by 2 orders than RCC tumor cells, and the disruption of tumor vessels was efficiently induced. Collectively, the dual-ligand LP is promising carrier for the treatment of drug resistant RCC via the disruption of TECs., (Copyright © 2012 Elsevier B.V. All rights reserved.)