An algorithm-based technique for counting mitochondria in cells using immunohistochemical staining of formalin-fixed and paraffin-embedded sections

PURPOSE

Visualizing mitochondria in cancer cells from human pathological specimens may improve our understanding of cancer biology. However, using immunohistochemistry to evaluate mitochondria remains difficult because almost all cells contain mitochondria and the number of mitochondria per cell may have important effects on mitochondrial function. Herein, we established an objective system (Mito-score) for evaluating mitochondria using machine-based processing of hue, saturation, and value color spaces.

METHODS

The Mito-score was defined as the number of COX4 (mitochondrial inner membrane) immunohistochemistry-positive pixels divided by the number of nuclei per cell. The system was validated using four lung cancer cell lines, normal tissues, and lung cancer tissues (199 cases).

RESULTS

The Mito-score correlated with MitoTracker, a fluorescent dye used to selectively label and visualize mitochondria within cells under a microscope (R2 = 0.68) and with the number of mitochondria counted using electron microscopy (R2 = 0.79). Histologically, the Mito-score of small cell carcinoma (57.25) was significantly lower than that of adenocarcinoma (147.5, p < 0.0001), squamous cell carcinoma (120.6, p = 0.0004), and large cell neuroendocrine carcinoma (111.8, p = 0.002).

CONCLUSION

The Mito-score method enables the analysis of the mitochondrial status of human formalin-fixed paraffin-embedded specimens and may provide insights into the metabolic status of cancer.

CDC7 inhibition induces replication stress-mediated aneuploid cells with an inflammatory phenotype sensitizing tumors to immune checkpoint blockade

Serine/threonine kinase, cell division cycle 7 (CDC7) is critical for initiating DNA replication. TAK-931 is a specific CDC7 inhibitor, which is a next-generation replication stress (RS) inducer. This study preclinically investigates TAK-931 antitumor efficacy and immunity regulation. TAK-931 induce RS, generating senescence-like aneuploid cells, which highly expressed inflammatory cytokines and chemokines (senescence-associated secretory phenotype, SASP). In vivo multilayer-omics analyses in gene expression panel, immune panel, immunohistochemistry, RNA sequencing, and single-cell RNA sequencing reveal that the RS-mediated aneuploid cells generated by TAK-931 intensively activate inflammatory-related and senescence-associated pathways, resulting in accumulation of tumor-infiltrating immune cells and potent antitumor immunity and efficacy. Finally, the combination of TAK-931 and immune checkpoint inhibitors profoundly enhance antiproliferative activities. These findings suggest that TAK-931 has therapeutic antitumor properties and improved clinical benefits in combination with conventional immunotherapy.

Integrative Systematics and Biogeography of the Hydrozoans (Leptothecata: Eirenidae) Eirene menoni Kramp, 1953 and Eirene lacteoides Kubota and Horita, 1992 from Japan and China with Comments on Pacific Ocean Distributions

The hydrozoan family Eirenidae is known scientifically for its morphological plasticity and challenges in species identification. We used an integrative taxonomic approach based on morphological, molecular and life history evidence to systematically assess field-collected medusae of Eirene menoni Kramp 1953 and captive raised polyps of both E. menoni and E. lacteoides Kubota and Horita 1992. Following morphological review, we updated the genus description to include the presence of rudimentary bulbs (warts) on the ring canal in at least eight of the 24 valid Eirene species. We propose the potential for the mature E. menoni hydrotheca to develop into a gonotheca. However, this proposal will require additional study for verification. We provide validated distribution records from the Indo-Pacific Ocean for E. menoni,and updated collection records for E. lacteoides from the Yellow and East China Seas, and public aquaria-cultured specimens from Japan and Hawaii, using cytochrome c oxidase I (COI) sequences that we generated and compared with those from GenBank. The COI gene reliably separated four species, each forming a monophyletic clade with strong bootstrap support and low mean intraspecific molecular divergences (≤ 1%) within clades. However, some of the deeper nodes of the tree remained poorly resolved, and our analysis failed to demonstrate monophyly among eirenid genera Eirene and Tima. Our integrative taxonomic approach is essential in confirming species identity within the family Eirenidae and genus Eirene,and we have also identified a likely range expansion of E. lacteoides to Hawaii.

Factors predicting oral and maxillofacial fractures after falling and factors predicting the duration of treatment

BACKGROUND/AIM

The first objective of this study was to identify predictive factors for oral and maxillofacial fractures at the initial response to the patient. The second objective was to determine the factors influencing the incidence of treatment duration of more than 1 month using the information shown in the medical record.

MATERIALS AND METHODS

Hospital records from 2011 to 2019 were reviewed to identify patients who had sustained oral and maxillofacial injuries by falling or falling from a height. Patterns and types of oral and maxillofacial injury, injury severity, and background of the injury were collected from the hospital records. The variables independently associated with a treatment duration of more than 1 month were determined by logistic regression analysis.

RESULTS

In total, 282 patients (150 men, 132 women; median age, 17.5 years) were selected for analysis. Maxillofacial fractures were observed in 20.9% of patients (59/282); among these, mandibular fractures were the most common (47/59). Logistic regression analysis showed that age (odds ratio [OR], 1.026), nighttime occurrence (OR, 2.192), and upper face injury (OR, 20.704) were independent predictive factors for having a maxillofacial fracture. Additionally, the number of injured teeth (OR, 1.515) and the use of intermaxillary fixation (OR, 16.091) were independent predictors of treatment duration of more than 1 month.

CONCLUSIONS

These results may be useful in the initial management of maxillofacial injuries in terms of better-informing patients injured by falling their expected treatment duration and managing the psychological impacts of a long treatment duration.

Effectiveness of Albumin-Fused Thioredoxin against 6-Hydroxydopamine-Induced Neurotoxicity In Vitro

Parkinson's disease (PD) is a neurodegenerative disorder caused by oxidative stress-dependent loss of dopaminergic neurons in the substantia nigra and elevated microglial inflammatory responses. Recent studies show that cell loss also occurs in the hypothalamus in PD. However, effective treatments for the disorder are lacking. Thioredoxin is the major protein disulfide reductase in vivo. We previously synthesized an albumin-thioredoxin fusion protein (Alb-Trx), which has a longer plasma half-life than thioredoxin, and reported its effectiveness in the treatment of respiratory and renal diseases. Moreover, we reported that the fusion protein inhibits trace metal-dependent cell death in cerebrovascular dementia. Here, we investigated the effectiveness of Alb-Trx against 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in vitro. Alb-Trx significantly inhibited 6-OHDA-induced neuronal cell death and the integrated stress response. Alb-Trx also markedly inhibited 6-OHDA-induced reactive oxygen species (ROS) production, at a concentration similar to that inhibiting cell death. Exposure to 6-OHDA perturbed the mitogen-activated protein kinase pathway, with increased phosphorylated Jun N-terminal kinase and decreased phosphorylated extracellular signal-regulated kinase levels. Alb-Trx pretreatment ameliorated these changes. Furthermore, Alb-Trx suppressed 6-OHDA-induced neuroinflammatory responses by inhibiting NF-κB activation. These findings suggest that Alb-Trx reduces neuronal cell death and neuroinflammatory responses by ameliorating ROS-mediated disruptions in intracellular signaling pathways. Thus, Alb-Trx may have potential as a novel therapeutic agent for PD.

Abstract 5739: Targeting WEE1 to improve the therapy of KRAS G12C mutant non-small cell lung cancer

Background: While sotorasib is the first clinically approved small-molecule inhibitor of KRAS G12C in non-small-cell lung cancer (NSCLC), efficacy of sotorasib alone is limited, presumably due to adaptive resistance mechanisms in cancer cells. To expand therapeutic potential of sotorasib, combination strategies need to be developed. In this study, we conducted a large-scale screening to identify novel combination candidates with sotorasib. In addition, molecular mechanisms of synergistic effects were investigated in multiple preclinical models.

Methods: To identify novel combination partners of sotorasib, we conducted high-throughput screening using a kinase inhibitor library containing 1,400 chemical compounds. Anti-proliferative and apoptotic effects in vitro were assessed by ATP-based cell viability assay and/or clonogenic assay, and caspase 3/7 assay and/or Annexin V assay, respectively. Synergistic effects were evaluated by calculating the BLISS index and visualized by SynergyFinder Plus. Immunoblotting was performed using antibodies against pCDK1 (Tyr15), pERK, pAkt, MCL1, BIM, PUMA, BCL2, or BCL-xL. In vivo efficacy studies were performed using a KRAS G12C mutant H358 xenograft nude mouse model.

Results: Through the large-scale unbiased combination screening of -1,400 kinase inhibitors, we identified a WEE1 inhibitor (AZD1775), a G2/M checkpoint abrogator in clinical-stage development, as a promising combination partner of sotorasib in KRAS G12C mutant NSCLC. The synergistic effects in vitro were broadly observed in multiple KRAS G12C mutant NSCLC cell lines, regardless of single-agent sensitivity to sotrasib or co-occurring oncogenic mutation profiles. The combination treatment upregulated pro-apoptotic protein BIM, leading to apoptosis. In vivo efficacy studies in H358-xenografted models also demonstrated remarkable tumor regression and durable response in mice treated with sotorasib and AZD1775 compared to ones with a single agent alone.

Conclusion: We identify AZD1775, a WEE1 inhibitor, as a novel combination candidate, which enhanced the anti-tumor activity of sotorasib both in vitro and in vivo preclinical models. These findings can lead to a novel therapeutic strategy for KRAS G12C mutant NSCLC.

Citation Format: Gaku Yamamoto, Kosuke Tanaka, Ryo Kamata, Shunta Mori, Jie Liu, Toyohiro Yamauchi, Yuta Sakae, Akihiro Ohashi, Susumu S. Kobayashi. Targeting WEE1 to improve the therapy of KRAS G12C mutant non-small cell lung cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5739.

Analysis of micrognathia with obstructive sleep apnea syndrome improved by a combination of Le Fort I with horseshoe osteotomies, mandibular distraction osteogenesis, and genioplasty

The relationship between microgenia and obstructive sleep apnea syndrome is well known. 27-year-old woman. She underwent a combination of Le Fort I with horseshoe osteotomies and mandibular distraction osteogenesis and genioplasty. She was satisfied with the aesthetics of her face, with an AHI of 7.8/h.

Bone marrow-derived vasculogenesis leads to scarless regeneration in deep wounds with periosteal defects

Deep skin wounds with periosteal defects, frequently caused by traffic accidents or radical dissection, are refractory. Transplant surgery is frequently performed, but patients are subjected to stress for long operation periods, the sacrifice of donor regions, or several complications, such as flap necrosis or intractable ulcers. Even if the defects are covered, a scar composed of fibrous tissue remains in the body, which can cause itching, dysesthesia, or repeated ulcers because of the lack of distribution of peripheral nerves or hair follicles. Thus, treatments with the aim of regenerating lost tissue for deep wounds with periosteal defects are needed. Here, we show that the use of gelatin sponges (GS), which have been used as haemostatic materials in clinical practice, allowed the regeneration of heterogeneous tissues, including periosteum, skin, and skin appendages, when used as scaffolds in deep wounds with periosteal defects in rats. Bone marrow transplantation in rats revealed the mechanism by which the microenvironment provided by GS enabled bone marrow-derived cells (BMDCs) to form a vascular niche, followed by regeneration of the periosteum, skin, or skin appendages such as hair follicles by local cells. Our findings demonstrated that vascular niche formation provided by BMDCs is crucial for heterogeneous tissue regeneration.

Use of bronchoalveolar lavage in diagnosing angioimmunoblastic T‐cell lymphoma: A case report

Angioimmunoblastic T‐cell lymphoma (AITL) is a type of peripheral T‐cell tumour that belongs to the group of non‐Hodgkin's lymphomas. Pulmonary lesions can be found in 7%–10% of AITL cases. Imaging findings of the lungs varied; however, immunoblastic infiltration in the lungs is rare. Our patient was a 73‐year‐old man who received repeated chemotherapy for AITL. Fourth‐line therapy using romidepsin controlled the illness, but the patient was hospitalized for dyspnoea and an infiltrative shadow. We performed bronchoalveolar lavage (BAL), and the culture was positive for Haemophilus influenzae. The patient was initially discharged with antibiotic therapy, but hospitalized again. Antibiotics were ineffective and the patient required mechanical ventilation. BAL was performed again, after which fluid cytology revealed immunoblast‐like atypical cells. Therefore, the patient was diagnosed with pulmonary infiltration due to AITL. Steroid therapy proved ineffective, and the patient died. BAL was used to effectively diagnose pulmonary AITL infiltration.

Comparison of the wound-healing efficacy of gelatin sponge dressings and that of artificial dermis using atelocollagen in a rat cranial periosteal defect model

In oral surgery, tissue loss may occur in some cases, resulting in bone exposure and subsequent wound infection and possible scar formation during secondary healing. In this study, Terudermis^® Artificial Dermis (AD-T), a dermal defect graft made from processed bovine dermis collagen and gelatin sponge (GS) were used as dressings on 100-mm² wounds with exposed bone on the heads of rats. For the control group, the wound was left exposed. The wound-healing efficacy of the treatment was compared macroscopically and histologically among the three groups at 1, 2, and 4 weeks after surgery. Complete wound healing was achieved faster in the AD-T group than in the GS group, and osteoblasts appeared on the bone surface, indicating accelerated bone remodeling. Furthermore, in the AD-T group, there was an increased production of newly formed blood vessels, fibroblasts and osteoblasts positive for anti-cortactin antibodies, which are believed to contribute to wound healing. Our findings suggest that AD-T is better than GS as a wound dressing material.

Tima nigroannulata (Cnidaria: Hydrozoa: Eirenidae), a New Species of Hydrozoan from Japan

Tima nigroannulata sp. nov. is described from medusae collected in shallow waters of four prefectures on the Pacific coast of Japan (Miyagi, Fukushima, Kanagawa, and Miyazaki), as well as from cultures maintained at two aquaria (Enoshima Aquarium, Kanagawa Prefecture; Tsuruoka City Kamo Aquarium, Yamagata Prefecture). Adult medusae differ from those of other known species of the genus Tima Eschscholtz, 1829 in the following combination of characters: (1) umbrella usually hemispherical or higher, (2) marginal tentacles up to 50 or more in number; and (3) black pigment granules form a ring around the umbrella rim, and sometimes extend onto the tentacles and radial canals. Their hydroids, from aquarium cultures, have stolonal colonies with pedicels of varied length, vestigial hydrothecae, slender and vase- to club-shaped hydranths, and a whorl of about 20 filiform tentacles with an intertentacular web basally. Medusa buds develop singly within gonothecae that arise from the hydrothecal pedicels. The cnidomes of both hydroid and medusa stages comprise heteronemes, provisionally identified as microbasic mastigophores. Medusae of T. nigroannulata are confirmed as a unique, cohesive lineage by comparing mtDNA COI sequence fragments with those from two congeners, resulting in three well-supported reciprocally monophyletic clades, one representing each species. Records of the western Atlantic medusa Tima formosa L. Agassiz, 1862 from Japan overlap those of T. nigroannulata, and are believed to have been based on the new species described herein.

Successful rechallenge with cetuximab after progression with nivolumab for recurrent cervical lymph node metastasis from carcinoma of the tongue

We can infer that the immunostimulatory effect of nivolumab and reactivation of cetuximab enhance the antitumor effect of the therapy.

The Number of Larval Molts Is Controlled by Hox in Caterpillars

Animals with exoskeletons molt for further growth. In insects, the number of larval (or nymphal) molts varies inter- and intra-specifically, and it is widely accepted that the variation in the number of larval molts is an adaptive response to diverse environmental conditions.^1-5 However, the molecular mechanism that underlies the variety and plasticity in the number of larval molts is largely unknown. In the silkworm, Bombyx mori, there are strains that molt three, four, or five times, and these numbers are determined by allelic variation at a single autosomal locus, Moltinism (M).^6-9 Here, we demonstrate that the Hox gene Sex combs reduced (Scr) is responsible for the phenotypes of the M locus. Scr is selectively expressed in the larval prothoracic gland (PG), an endocrine organ that produces molting hormones.²Scr represses the biosynthesis of molting hormones in the PG, thereby regulating the incremental increase in body size during each larval instar. Our experiments consistently suggest that the differential expression levels of Scr among the three M alleles result in different growth ratios that ultimately lead to the different number of larval molts. Although the role of Hox genes in conferring segmental identity along the body axis and in molding segment-specific structure later in development has been well established,^10-13 the present study identifies an unexpected role of Hox gene in hormone biosynthesis. This new role means that, in addition to shaping segment-specific morphology, Hox genes also drive the evolution of life history traits by regulating animal physiology.

Differences in the Knowledge and Experience of Physicians and Dentists About Medication-Related Osteonecrosis of the Jaw in Osteoporotic Patients

AIM

Prevention of medication-related osteonecrosis of the jaw (MRONJ) in patients with osteoporosis requires the cooperation of physicians and dentists. We investigated the knowledge, experience, and behaviour related to medical and dental cooperation for MRONJ prevention in patients with osteoporosis between physicians and dentists practising in the Shiga prefecture.

MATERIALS AND METHODS

We conducted a cross-sectional study to investigate the cooperation between practising physicians and dentists for preventing osteonecrosis of the jaw (ONJ) in patients with osteoporosis using 2 separate questionnaires from July 28, 2018, to February 3, 2019.

RESULTS

Of 461 dentists who were sent the questionnaires at their dental clinics, 307 (67%) responded via fax. Of 846 physicians who were sent the questionnaire at their clinics, 378 (45%) responded via fax. Of these, 268 (32%) were finally analysed because 110 (13%) physicians had never treated patients with osteoporosis; 50% dentists and 24% physicians were familiar with the MRONJ position paper in Japan, and 39% dentists and 9% physicians had encountered MRONJ in their clinical practice. A total of 30% physicians had requested oral health care by a dentist before administering bone-modifying agents (BMA) therapy. The knowledge and experience of MRONJ differed between physicians and dentists.

CONCLUSION

The behaviour of physicians and dentists was insufficient to enable medical and dental cooperation for the prevention of MRONJ in patients with osteoporosis. The lack of cooperation between physicians and dentists during osteoporosis treatment in the Shiga prefecture in Japan is documented in this study.

Similarities and differences in metabolites of tongue cancer cells among two- and three-dimensional cultures and xenografts

Metabolic programming of cancer cells is an essential step in transformation and tumor growth. We established two-dimensional (2D) monolayer and three-dimensional (3D) cultures, the latter called a "tissueoid cell culture system", using four types of tongue cancer cell lines. We also undertook a comprehensive metabolome analysis of three groups that included xenografts created by transplanting the cell lines into nude mice. In addition, we undertook a functional analysis of the mitochondria, which plays a key role in cancer metabolism. Principal component analysis revealed the plots of the four cell lines to be much narrower in 2D culture than in 3D culture and xenograft groups. Moreover, compared to xenografts, the 2D culture had significantly lower levels of most metabolites. These results suggest that the unique characteristics of each cell disappeared in 2D culture, and a type of metabolism unique to monolayer culture took over. Conversely, ATP production, biomass synthesis, and maintenance of redox balance were shown in 3D culture using sufficient nutrients, which closely resembled the metabolic activity in the xenografts. However, there were several differences between the metabolic activity in the 3D culture and xenografts. In vivo, the cancer tissue had blood flow with stromal cells present around the cancer cells. In the xenografts, we detected metabolized and degraded products in the liver and other organs of the host mice. Furthermore, the 3D system did not show impairment of mitochondrial function in the cancer cells, suggesting that cancer cells produce energy simultaneously through mitochondria, as well as aerobic glycolysis.

Sensitive Method for the Identification of Potential Sensitizing Impurities in Reaction Mixtures by Fluorescent Nitrobenzoxadiazole-Labeled Glutathione

Allergic contact dermatitis is a critical issue in the development of new chemicals. Minor impurities with strong skin-sensitizing properties can be generated as byproducts. However, it is very difficult to identify these skin sensitizers in product mixtures. In this study, fluorescent nitrobenzoxadiazole-labeled glutathione (NBD-GSH) was synthesized to identify small amounts of skin sensitizers in reaction mixtures. Twelve known skin sensitizers and three nonsensitizers were reacted with NBD-GSH. Adducts formed only with the skin sensitizers, which allowed for their detection by a fluorescence detector. Liquid chromatography-mass spectrometry (LC-MS) analyses showed that NBD-GSH reacted with the skin sensitizers via its thiol and amino groups. An adduct of NBD-GSH with the strong skin sensitizer 1-chloro-2,4-dinitrobenzene was detected with a limit of detection of 6 × 10^-8 mol/L by high-performance liquid chromatography with fluorescence detection. When a reaction mixture from primary alcohol oxidation was incubated with NBD-GSH, a NBD-GSH adduct formed with skin-sensitizing aldehyde impurities and could be specifically detected by LC-MS with fluorescence detection. This method will be useful for detection and identification of small amounts of skin sensitizers in raw materials, intermediates, reaction mixtures, and end products in the chemical industry.

Maxillofacial Injuries in Cyclists: A Biomechanical Approach for the Analysis of Mechanisms of Mandible Fractures

PURPOSE

The investigators characterized the occurrence of maxillofacial injuries in cyclists and biomechanically analyzed the mechanisms of mandible fractures.

METHODS

We retrospectively analyzed injury data and performed biomechanical analyses with finite element models. Hospital records from 2011 through 2019 were reviewed to identify patients who had sustained oral and maxillofacial injuries while riding a bicycle. Patients with maxillofacial fractures were compared to those without. Logistic regression analysis was performed to identify which variables were independently associated with the occurrence of maxillofacial fractures. To reconstruct the injury scenario (one in which a person falls from a bicycle and contacts the road surface with their face), computer simulations using The Total Human Model for Safety model were performed.

RESULTS

The hospital records of 94 patients (62 men, 32 women; 26.1 ± 17.3 years of age) who sustained oral and maxillofacial injuries while riding a bicycle were reviewed. Twenty patients (21.3%) sustained maxillofacial fractures; mandible fractures were most common (16 patients). Patients with maxillofacial fractures were significantly older and had higher severity injuries; however, logistic regression analysis showed that only age was an independent predictor of the occurrence of maxillofacial fracture (odds ratio, 1.03; P = .025). In simulations, higher von Mises stresses were found in the mandible when the cyclist fell with the neck extended and the body horizontal, and consequently, the center of mandibular body strikes the road surface. Contact forces were approximately 8 kN. High tensile stresses occurred laterally and high compressive stresses occurred medially in the mandibular ramus, which indicated that the mandibular ramus deformed in the transverse plane.

CONCLUSION

Biomechanical analyses show that mandible fractures can occur when a cyclist falls from a bicycle and their lower face strikes the road's surface.

Factors influencing the long-term hospitalization of bicyclists and motorcyclists with oral and maxillofacial injuries

BACKGROUND/AIM

Because bicyclists and motorcyclists with oral and maxillofacial injuries often suffer from disabilities requiring long-term treatment, reducing the severity of such injuries is a valuable objective for improving these people's quality of life (QOL). The aims of this study were, first, to present the prevalence and patterns of oral and maxillofacial injuries of bicyclists and motorcyclists and to compare the features of these injuries and, second, to determine the factors contributing to long-term hospitalization for these patients and to propose effective preventive measures.

MATERIAL AND METHODS

This was a single-center retrospective analysis. Hospital records from 2011 through 2018 were reviewed for all patients who had sustained oral and maxillofacial injuries in bicycle or motorcycle collisions and had presented at a university hospital which was the only hospital in the region attended 24 hours per day by oral and maxillofacial surgeons. Characteristics of the oral and maxillofacial injuries, injury severity, and factors influencing the length of hospitalization were examined.

RESULTS

Records of 130 patients (82 bicyclists and 48 motorcyclists) with a mean age of 28.0 years were analyzed. Thirty-three patients (25.4%) had maxillofacial fractures, with 41 fracture lines while 103 patients (79.2%) had dental injuries and 57 patients (43.8%) had soft-tissue injuries. The distribution and prevalence of oral and maxillofacial injuries were similar for bicyclists and motorcyclists. However, motorcyclists had significantly higher Abbreviated Injury Scale (AIS) scores for facial injuries and the maximum AIS score than did bicyclists. According to a multiple regression analysis, the number of fracture lines and the requirement for intermaxillary fixation were independent factors influencing long-term hospitalization (standard regression coefficients: 6.795 and 6.715, respectively; P < .001).

CONCLUSIONS

The number of fracture lines and the use of intermaxillary fixation were independent factors influencing long-term hospitalization of both bicyclists and motorcyclists with oral and maxillofacial injuries.

Application of "Tissueoid Cell Culture System" Using a Silicate Fiber Scaffold for Cancer Research

BACKGROUND

We developed a 3-dimensional (3D) culture system using a high-purity silica fiber scaffold of unwoven sheets called CellbedTM.

METHODS

We used adherent colon and esophagogastric junction adenocarcinoma cells, tongue squamous cell carcinoma (SqCC) cells, and nonadherent gastric cancer cells. These cells were subjected to staining with various substances and observed by electron microscopy. To evaluate the effects of extracellular matrix in carcinoma tissues, SqCC cells were cultured in Cellbed coated with collagens I, III, and IV.

RESULTS

Especially well-differentiated carcinoma cells cultured in this 3D system showed their own unique characteristics: luminal formation in adenocarcinoma cells and cell stratification and keratinization in SqCC cells. Scanning electron microscopy revealed the proliferation of cancer cells with cytoplasm entwined in Cellbed. Intercellular desmosomes in squamous epithelia were detected by transmission electron microscopy of vertical cross sections. SqCC cells cultured in Cellbed coated with collagen IV showed enhanced invasive and proliferative abilities.

CONCLUSION

Because the morphology of cancer cells cultured in this 3D culture system is similar to that in living organisms, we called the system a "tissueoid cell culture system." Coating with collagen IV enables the modification of cell-matrix interactions as well as recapitulation of the in vivo microenvironment.

Pulmonary capillary hemangiomatosis-predominant vasculopathy in a patient with rheumatoid arthritis-associated interstitial lung disease: An autopsy report

Pulmonary capillary hemangiomatosis (PCH) is a rare cause of pulmonary hypertension (PH) associated with poor prognosis. Clinically, it is characterized by severe hypoxemia, centrilobular ground-glass opacities on computed tomography, and pulmonary congestion triggered by pulmonary vasodilating therapy. In some cases, PCH has been reported to develop with other disorders including connective tissue disease; however, to date, no reports have described PCH in a patient with rheumatoid arthritis. We report a case of a 59-year-old male PCH patient with rheumatoid arthritis and associated pulmonary fibrosis. He was initially diagnosed with severe group 3 PH and received sildenafil, which generated a favorable hemodynamic response. However, 5 years later, his pulmonary hemodynamics deteriorated, and he died at the age of 67. An autopsy was performed, and thickening of alveolar septa and capillary proliferation, pathological features of PCH, were extensively observed in both lungs. We discuss when PCH developed, how sildenafil improved his hemodynamics, and how PCH could be clinically detected by noninvasive evaluations.

Expressions of ezrin, ERK, STAT3, and AKT in tongue cancer and association with tumor characteristics and patient survival

Background

Ezrin, ERK, STAT3, and AKT are proteins that are overexpressed in various types of cancer, although their expressions in tongue cancer has received less focus. This study aimed to address associations between the expression levels of these proteins and with characteristics of the tumor and patient survival.

Methods

We performed immunohistochemical staining of ezrin, ERK, STAT3, and AKT in tumors from patients with tongue carcinoma in situ (CIS, n = 17) and tongue squamous cell carcinoma (SCC, n = 46). Statistical differences between the SCC versus the CIS cohorts were estimated by calculations of bivariate odds ratios of low versus high expression of the proteins. Fisher's exact tests were used to appraise interassociations between the proteins, as well as expression levels versus patient and tumor characteristics. Survival based on Kaplan–Meier statistics in combination log‐rank tests were used to address potential effects of the patient and tumor characteristics versus 5‐year survival rate.

Results

The relative high: low expression of all four proteins in the two cohorts differed, and particularly ERK was markedly overexpressed in the SCC versus the CIS cohort (odds ratio = 45.3, p < .01). The relative high: low expression each protein versus patient and tumor characteristics; showed associations between AKT expression and T stage (p = .002) plus node metastases (p = .12), and between ERK expression and drinking (p = .01) and smoking history (p = .01). There was no significant difference observed between ERK and the three other molecules, nor any significant difference between the degree of expression of each protein and the 5‐year disease‐specific survival rate.

Conclusion

Ezrin, ERK, STAT3, and AKT appear to be involved in the progress from carcinoma in situ in the tongue into squamous cell carcinoma. ERK in particular is overexpressed, suggesting that ERK may be a novel therapeutic target for preventing tongue cancer.

ERK phosphorylation functions in invadopodia formation in tongue cancer cells in a novel silicate fibre-based 3D cell culture system

To screen for additional treatment targets against tongue cancer, we evaluated the contributions of extracellular signal-related kinase (ERK), AKT and ezrin in cancer development. Immunohistochemical staining showed that ERK and ezrin expressions were significantly higher in invasive squamous cell carcinoma than in carcinoma in situ. To investigate the roles of ERK and ezrin in cancer development, we used the non-woven silica fibre sheet Cellbed^TM with a structure resembling the loose connective tissue morphology in a novel 3D culture system. We confirmed that the 3D system using Cellbed^TM accurately mimicked cancer cell morphology in vivo. Furthermore, cell projections were much more apparent in 3D-cultured tongue cancer cell lines than in 2D cultures. Typically, under conventional 2D culture conditions, F-actin and cortactin are colocalized in the form of puncta within cells. However, in the 3D-cultured cells, colocalization was mainly observed at the cell margins, including the projections. Projections containing F-actin and cortactin colocalization were predicted to be invadopodia. Although suppressing ezrin expression with small interfering RNA transfection caused no marked changes in morphology, cell projection formation was decreased, and the tumour thickness in vertical sections after 3D culture was markedly decreased after suppressing ERK activity because both the invasion ability and proliferation were inhibited. An association between cortactin activation as well as ERK activity and invadopodia formation was detected. Our novel 3D culture systems using Cellbed™ are simple and useful for in vitro studies before conducting animal experiments. ERK contributes to tongue cancer development by increasing both cancer cell proliferation and migration via cortactin activation.

Extracellular signal-regulated kinases (ERKs) are enzymes that are involved in a variety of cell functions, and one in vitro study suggests that ERKs play a role in tongue cancer development by increasing cancer cell proliferation and migration. Using a novel 3-D cell culture system called Cellbed to mimic cancer cell morphology, a team headed by Ken-ichi Mukaisho at Shiga University of Medical Science, Japan found that ERKs activate cortactin (a protein located in the cell cytoplasm) and contribute to the formation of invadopodia (invasive cell protrusions associated with cancer cells) in tongue cancer cells and tumor development. The authors conclude that experimental 3-D cell culture systems employing Cellbed are easily implemented and useful for in vitro studies before conducting animal experiments and that they can be widely applied in cancer research.

Single-channel Recordings of TREK-1 K+ Channels in Periodontal Ligament Fibroblasts

The periodontal ligament (PDL) works as a suspensory ligament when external mechanical stress is placed on the teeth. PDL fibroblasts, the principal cells in the PDL, are responsible for many PDL functions. We hypothesized that mechanosensitive ion channels are present in human PDL fibroblasts, which are capable of responding to mechanical stress during normal function of the tissue. Using patch-clamp techniques, we detected mechanosensitive TREK-1 K+ channels (a member of the two-pore-domain K+ channel family), whose single-channel conductance was 104 pS in symmetrical K+-rich solutions. The open probability of the channel was low in the quiescent state, but it was strongly increased by the induction of membrane stretch. Arachidonic acid also enhanced the channel activity. RT-PCR and immunocytochemical observations showed the expression of TREK-1 K+ channels in PDL fibroblasts. The results suggest that the activation of TREK-1 K+ channels by masticatory stress contributes to the hyperpolarization of PDL fibroblasts.

Comparison of the wound healing efficacy of polyglycolic acid sheets with fibrin glue and gelatin sponge dressings in a rat cranial periosteal defect model

Oral surgical procedures occasionally require removal of the periosteum due to lesions, and these raw bone surfaces are prone not only to infection but also to scar formation during secondary healing. The objective of this study was to identify successful methods for reconstruction using periosteal defect dressings. We created 1-cm² defects in the skin and cranial periosteum of 10-week-old male Wistar rats under isoflurane anesthesia. The animals were assigned to three defect treatment groups: (1) polyglycolic acid sheets with fibrin glue dressing (PGA-FG), (2) Spongel® gelatin sponge dressing (GS), and (3) open wound (control). Postoperative wound healing was histologically evaluated at 2, 4, and 6 weeks. The moist conditions maintained by the GS and PGA-FG treatments protected the bone surface from the destructive effects of drying and infection. Complete wound healing was observed in the GS group but not for all animals in the PGA-FG and control groups. Histologically, osteoblast proliferation on bone surfaces and complete epithelialization with adnexa were observed in the GS group at 6 weeks after surgery. In contrast, PGA sheets that had not been absorbed inhibited osteoblast proliferation and delayed wound healing in the PGA-FG group. Wound surface dressings maintain a moist environment that promotes wound healing, but PGA materials may not be suitable for cases involving exposed periosteum or bone surfaces due to the observed scar formation and foreign-body reaction.

Duodenal Contents Reflux-Induced Laryngitis in Rats: Possible Mechanism of Enhancement of the Causative Factors in Laryngeal Carcinogenesis

Objectives:

The main factors considered responsible for the onset of laryngeal cancer are tobacco smoking and alcohol abuse. Recently, gastroesophageal reflux has also been implicated as a causative factor in several laryngeal disorders, including laryngeal cancer. However, the significance of gastroesophageal reflux in laryngeal cancer is controversial.

Methods:

We investigated the histologic features of the esophagus and larynx in a rat model of reflux of the duodenal contents. Cell proliferation was also evaluated in laryngeal samples by detection of Ki67 antigen.

Results:

In this reflux model, laryngitis with infiltration of inflammatory cells and proliferation of small mucous glands was evident from 10 weeks after operation, and basal cell hyperplasia around the epiglottis and hyperplastic changes in the larynx were detected at 30 weeks. No dysplastic or malignant lesions were detected in the laryngeal samples within the duration of the experiment, in spite of detection of malignancy in 31.3% of lesions in esophageal samples at 30 weeks. The Ki67 index at each week was significantly higher than that of the control animals.

Conclusions:

Previous studies have shown smoking and alcohol abuse to have refluxogenic effects. Reflux of duodenal contents causes laryngitis. Reflux does not appear to be an independent risk factor for laryngeal carcinogenesis, but it may enhance the acknowledged etiologic risk factors, namely, smoking and alcohol abuse, by promoting cell proliferation.

Gingival epithelial cells support osteoclastogenesis by producing receptor activator of nuclear factor kappa B ligand via protein kinase A signaling

BACKGROUND AND OBJECTIVE

Periodontal disease is dental plaque-induced inflammatory disease of the periodontal tissues that results in bone loss in the affected teeth. During bone resorption, receptor activator of nuclear factor kappa B ligand (RANKL) is an essential factor that regulates osteoclastogenesis. Recently, we found that gingival epithelial cells (GECs) in periodontal tissue produce RANKL, the expression of which is regulated by tumor necrosis factor-α and protein kinase A signaling. In this study, we asked whether RANKL-producing GECs induce bone marrow macrophages (BMMs) to form osteoclasts in a co-culture system.

MATERIAL AND METHODS

Ca9-22 GECs and osteoclast precursor BMMs were co-cultured with or without the protein kinase A signaling activator forskolin or inhibitor H89 to examine whether the RANKL-producing GECs could be induced to form osteoclasts, as determined using a pit formation assay.

RESULTS

Osteoclasts formed spontaneously in co-cultures of Ca9-22 cells and BMMs, even in the absence of RANKL. The cells were cultured on bone slices for 14 d, at which time resorption pits were observed. Forskolin treatment significantly increased osteoclast numbers in these co-cultures, but forskolin alone did not induce osteoclast formation by BMMs.

CONCLUSION

GECs producing RANKL are able to support osteoclastogenesis in an in vitro co-culture system using GECs and BMMs, in a process promoted by forskolin.

Quantitative laser diffraction method for the assessment of protein subvisible particles

Laser diffraction (LD) has been recognized as a method for estimating particle size distribution. Here, a recently developed quantitative LD (qLD) system, which is an LD method with extensive deconvolution analysis, was employed for the quantitative assessment of protein particles sizes, especially aimed at the quantification of 0.2-10 μm diameter subvisible particles (SVPs). The qLD accurately estimated concentration distributions for silica beads with diameters ranging from 0.2 to 10 μm that have refractive indices similar to that of protein particles. The linearity of concentration for micrometer-diameter silica beads was confirmed in the presence of a fixed concentration of submicrometer diameter beads. Similarly, submicrometer-diameter silica beads could be quantified in the presence of micrometer-diameter beads. Subsequently, stir- and heat-stressed intravenous immunoglobulins were evaluated by using the qLD, in which the refractive index of protein particles that was determined experimentally was used in the deconvolution analysis. The results showed that the concentration distributions of protein particles in SVP size range differ for the two stresses. The number concentration of the protein particles estimated using the qLD agreed well with that obtained using flow microscopy. This work demonstrates that qLD can be used for quantitative estimation of protein aggregates in SVP size range.

Differences in the developmental origins of the periosteum may influence bone healing

BACKGROUND AND OBJECTIVE

The jaw bone, unlike most other bones, is derived from neural crest stem cells, so we hypothesized that it may have different characteristics to bones from other parts of the body, especially in the nature of its periosteum. The periosteum exhibits osteogenic potential and has received considerable attention as a grafting material for the repair of bone and joint defects.

MATERIAL AND METHODS

Gene expression profiles of jaw bone and periosteum were evaluated by DNA microarray and real-time polymerase chain reaction. Furthermore, we perforated an area 2 mm in diameter on mouse frontal and parietal bones. Bone regeneration of these calvarial defects was evaluated using microcomputed tomography and histological analysis.

RESULTS

The DNA microarray data revealed close homology between the gene expression profiles within the ilium and femur. The gene expression of Wnt-1, SOX10, nestin, and musashi-1 were significantly higher in the jaw bone than in other locations. Microcomputed tomography and histological analysis revealed that the jaw bone had superior bone regenerative abilities than other bones.

CONCLUSION

Jaw bone periosteum exhibits a unique gene expression profile that is associated with neural crest cells and has a positive influence on bone regeneration when used as a graft material to repair bone defects. A full investigation of the biological and mechanical properties of jaw bone as an alternative graft material for jaw reconstructive surgery is recommended.

Pigmented keratocystic odontogenic tumor: A case report with review of the literature

Keratocystic odontogenic tumor (KCOT) is a relatively rare benign neoplasm of odontogenic origin. The squamous epithelium of KCOT usually does not contain melanocytes, however, pigmented KCOT has been documented, albeit extremely rarely. In the present study, we described an additional case of pigmented KCOT and review the clinicopathological features of this extremely rare lesion. A 23-year-old Japanese female presented with a relatively well-circumscribed round unilocular radiolucency that impacted the third molar in her right mandibula. Surgical resection was performed subsequent to a clinical diagnosis of KCOT. Histopathological study of the resected mandibular cyst showed that it was covered by a parakeratinized stratified squamous epithelium, which had slightly enlarged hyperchromatic nuclei. On the luminal surface, a wavy layer of parakeratin was observed. In addition, dendritic melanocytes without atypia were observed in approximately half of the squamous epithelium. Immunohistochemical analyses revealed that these melanocytes were positive for S-100 protein, Melan-A and HMB-45. Therefore, a diagnosis of pigmented KCOT was made. Review of the clinicopathological features of the previously reported cases of pigmented KCOT as well as the present case revealed that: i) this lesion occurs mostly in young persons (average age, 18 years) and shows female predominance; ii) most cases are solitary and involve the mandibula; and iii) the reported incidence is 0.36-10.6% and this difference may be associated with ethnicity. Thus, we described the ninth reported case of pigmented KCOT. The mechanism by which melanocytes appear and the difference in ethnic prevalence remain unclear. Additional clinicopathological studies are needed to clarify these issues.

Continuous taurocholic acid exposure promotes esophageal squamous cell carcinoma progression due to reduced cell loss resulting from enhanced vascular development

BACKGROUND

Refluxogenic effects of smoking and alcohol abuse may be related to the risk of esophageal squamous cell carcinoma (ESCC). The present study attempts to clarify the effects of continuous taurocholic acid (TCA) exposure, which is neither mutagenic nor genotoxic, on ESCC progression.

METHODS

A squamous carcinoma cell line (ESCC-DR) was established from a tumor induced in a rat model of gastroduodenal reflux. ESCC-DR cells were incubated with 2 mM TCA for ≥2 months. The effects of continuous TCA exposure were evaluated in vitro on cell morphology, growth, and invasion and in vivo on xenograft tumor growth in nude mice. Moreover, the mean level of secreted transforming growth factor (TGF)-β1 and vascular endothelial growth factor (VEGF) proteins in cell culture supernatants and mRNA synthesis of TGF-β1 and VEGF-A of ESCC cells were measured. The angiogenic potential was further examined by a migration assay using human umbilical vein endothelial cells (HUVECs).

RESULTS

Continuous TCA exposure induced marked formation of filopodia in vitro. Expression levels of angiogenic factors were significantly higher in the cells treated with TCA than in control cells. Tumor xenografts derived from cells pre-exposed to TCA were larger and more vascularized than those derived from control cells. In addition, TCA exposure increased HUVEC migration.

CONCLUSION

Continuous TCA exposure enhanced ESCC progression due to reduced cell loss in vivo. Cell loss was inhibited by TCA-induced vascular endothelial cell migration, which was mediated by TGF-β1 and VEGF-A released from ESCC cells.

Association of p62/SQSTM1 excess and oral carcinogenesis

p62/SQSTM1 (sequestosome1) has never been evaluated in oral epithelium. In order to clarify the role of p62/SQSTM1 in carcinogenesis in oral epithelium, both p62/SQSTM1 and Nrf2 were immunohistochemically evaluated in 54 carcinomas and 14 low grade dysplasias. p62/SQSTM1 knockdowns were also designed in oral cancer cells, and we analyzed the Nrf2 pathway, GSH contents and ROS accumulation. The association between p62/SQSTM1 excess and prognosis was addressed in a clinical cohort of oral carcinoma cases. p62/SQSTM1 excess was more obvious in carcinomas, but Nrf2 was abundant in almost all samples of the oral epithelium. In oral carcinoma cells, p62/SQSTM1 knockdown did not affect the Nrf2-Keap1 pathway but did significantly reduce GSH content with subsequent ROS accumulation, and caused cell growth inhibition in the irradiated condition. Finally, p62/SQSTM1 excess was associated with poor prognosis in a clinical cohort. In oral epithelial carcinogenesis, p62/SQSTM1 excess played a role in GSH induction rather than Nrf2 accumulation, and may cause resistance to cytotoxic stresses such as radiation or chemotherapy. Immunohistochemical evaluation of p62/SQSTM1 may be a potential significant marker to identify early carcinogenesis, chemo-radiotherapeutic resistance or poor prognosis of oral squamous cell carcinomas.

Lipopolysaccharide of Aggregatibacter actinomycetemcomitans up-regulates inflammatory cytokines, prostaglandin E2 synthesis and osteoclast formation in interleukin-1 receptor antagonist-deficient mice

BACKGROUND AND OBJECTIVE

The interleukin (IL)-1 receptor antagonist (Ra) binds to IL-1 receptors and inhibits IL-1 activity. However, it is unclear whether the IL-1Ra plays a protective role in periodontal disease. The purpose of this study was to compare IL-1Ra knockout (KO) and wild-type (WT) mice in regard to proinflammatory cytokine production, osteoclast formation and bone resorption in response to periodontal bacterial lipopolysaccharide (LPS).

MATERIAL AND METHODS

Peritoneal macrophages (Mφs) were obtained from 13-wk-old IL-1Ra KO and WT mice. Peritoneal Mφs were cultured with or without 10 μg/mL of Aggregatibacter actinomycetemcomitans LPS for 24 h. The levels of IL-1alpha (IL-1α), IL-1beta (IL-1β), tumor necrosis factor-α (TNF-α) and IL-6 were measured in periotoneal Mφs supernatant fluid (PM-SF) using an ELISA. Bone marrow cells were obtained from the mice and stimulated with PM-SF for 9 d, then stained with TRAP. The frequency of TRAP-positive multinucleated giant cell formation was calculated based on a fusion index. PM-SF-stimulated calvarial bone resorption was analyzed using micro-computed tomography, and calvarial histological analysis was performed using hematoxylin and eosin and TRAP staining. The expression of cyclooxygenase-2 (Cox2), prostanoid receptor EP4 (Ep4) and Rank mRNAs in bone marrow cells were measured using real-time quantitative PCR, while prostaglandin E2 (PGE2 ) production was determined by ELISA.

RESULTS

The levels of IL-1α, IL-1β, TNF-α and IL-6 in IL-1Ra KO mice PM-SF stimulated with A. actinomycetemcomitans LPS were significantly increased by approximately 4- (p < 0.05), 5- (p < 0.05), 1.3- (p < 0.05) and 6- (p < 0.05) fold, respectively, compared with the levels in WT mice. Moreover, osteoclast formation, expression of Rank, Ep4 and Cox2 mRNAs and production of PGE2 were significantly increased by approximately 2- (p < 0.05), 1.6- (p < 0.05), 2.5- (p < 0.05), 1.6- (p < 0.05) and 1.9- (p < 0.05) fold, respectively, in IL-1Ra KO mice stimulated with A. actinomycetemcomitans LPS compared with WT mice.

CONCLUSION

IL-1Ra regulates IL-1 activity and appears to reduce the levels of other inflammatory cytokines, including TNF-α and IL-6, while it also reduces expression of the EP4 receptor related to prostanoid sensitivity and osteoclast formation. These results suggest that IL-1Ra is an important molecule for inhibition of inflammatory periodontal bone resorption.

Lin28a is a putative factor in regulating cancer stem cell-like properties in side population cells of oral squamous cell carcinoma

Cancer stem cells (CSCs) are among the target cells of cancer therapy because they are uniquely involved in both cancer progression and sensitivity to chemotherapeutic agents. We identified side population (SP) cells, which are known to be an enriched population of CSC, in five oral squamous cell carcinoma (OSCC) cells (SCC9, SCC25, TOSCC7, TOSCC17, and TOSCC23). The percentages of SP cells ranged from 0% to 3.3%, with TOSCC23 cells showing the highest percentages of SP cells (3.3% of the total cell population). The SP cells isolated from TOSCC23 cells also showed greater cell proliferation and invasion compared to non-SP (MP) cells. Therefore, our initial findings suggested that SP cells were enriched for CSC-like cells. Furthermore, DNA microarray analysis revealed that the expression of cell proliferation-related and anti-apoptotic genes was greater in SP cells compared to MP cells. We focused on Lin28a, which showed the highest expression (approximately 22-fold) among the upregulated genes. The overexpression of Lin28a in TOSCC23 cells increased their proliferation, colony formation, and invasion. These findings suggest that Lin28a is an appropriate CSC target molecule for OSCC treatment.