The long proboscis of the aphid Stomaphis yanonis (Aphididae Lachninae) is advantageous for avoiding predation by tending ants.

Whether in ant-aphid mutualism the ants exert evolutionary selection pressure on aphid morphology has not yet been fully tested. Here, we tested whether the long proboscises of Stomaphis yanonis (Aphididae Lachninae) aphids confer an advantage in preventing predation by the tending ants. Specifically, we tested the hypothesis that aphids with a shorter proboscis would excrete less honeydew, making them more likely to be preyed upon by ants. Our results showed that aphid individuals with a shorter proboscis took up less phloem sap and excreted less honeydew than individuals with a longer proboscis. In addition, among aphids with a similar body size, those with a shorter proboscis were more susceptible to predation by ants than those with a longer proboscis. These results suggest that predation by tending ants, by exerting selection pressure on aphid proboscis morphology, has caused the aphids to evolve longer proboscises.

SLC7A9 as a Potential Biomarker for Lymph Node Metastasis of Esophageal Squamous Cell Carcinoma.

BACKGROUND: The expression of solute carrier (SLC) 7 family genes is reportedly associated with several malignancies. Here, we focused on SLC7A9 and investigated its expression, function, and clinical significance in esophageal squamous cell carcinoma (ESCC). METHODS: SLC7A9 transcription levels were evaluated in 13 ESCC cell lines, and polymerase chain reaction (PCR) array analysis was conducted to detect coordinately expressed genes with SLC7A9. SLC7A9 contributions to proliferation, invasion, and migration were evaluated in ESCC cells subjected to siRNA-mediated gene knockdown and pCMV6-entry plasmid-mediated overexpression. SLC7A9 expression was detected in 189 ESCC tissues by quantitative reverse-transcription (qRT)-PCR and correlated with clinicopathological parameters. RESULTS: The expression levels of SLC7A9 varied widely in ESCC cell lines and correlated with FGFBP1 expression. Knockdown of SLC7A9 significantly suppressed the proliferation, invasion, and migration of the ESCC cell lines. Moreover, overexpression of SLC7A9 enhanced cell proliferation and migration. In analyses of clinical specimens, SLC7A9 mRNA was overexpressed in the ESCC tissues compared with the adjacent normal esophageal tissues. High mRNA expression was significantly associated with high levels of squamous cell carcinoma-related antigen and carcinoembryonic antigen, advanced disease stage, and lymph node metastasis. High SLC7A9 expression was also significantly associated with poor disease-specific and disease-free survival, and lymph node recurrence after radical surgery, but not with the other recurrence patterns. On multivariate analysis, high SLC7A9 expression was an independent predictor of lymph node recurrence. CONCLUSIONS: SLC7A9 influences the malignant behavior of ESCC cells. Tumor SLC7A9 expression may serve as a novel biomarker for predicting lymph node metastasis and recurrence in ESCC patients.

Serial changes in cardiac sympathetic nervous function after transcatheter aortic valve replacement: A prospective observational study using 123I-meta-iodobenzylguanidine imaging.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) can rapidly improve cardiac sympathetic nervous function (CSNF) within 2 weeks in patients with aortic stenosis (AS). However, whether such short-term improvements will be sustained thereafter remains unclear. METHODS: Patients with severe AS who underwent TAVR between October 2017 and June 2019 were enrolled in this single-center, prospective, observational study. 123I-meta-iodobenzylguanidine imaging was performed at baseline, within 2 weeks after TAVR, and at 6 to 12 months post-TAVR to evaluate the heart-mediastinum ratio (H/M) and washout rate. RESULTS: Of 183 consecutive patients, 75 (19 men; median age: 86 years) were evaluated. The late H/M significantly improved within 2 weeks after TAVR (P = .041) and further improved over 6 to 12 months after TAVR (P = .041). Multivariate analysis revealed that the baseline mean aortic valve pressure gradient (mPG) was an independent predictor of mid-term improvement in the late H/M (> 0.1) (P = .037). Patients with a high baseline mPG (≥ 58 mmHg) exhibited a significantly greater increase in the late H/M than those with a low baseline mPG (< 42 mmHg) (0.24 vs 0.01; P = .029). CONCLUSION: CSNF demonstrated sustained improvement from within 2 weeks after TAVR until 6 to 12 months later. Such improvement was related to baseline hemodynamic AS severity.

Lysosomal-associated membrane protein family member 5 promotes the metastatic potential of gastric cancer cells.

BACKGROUND: Metastatic gastric cancer (GC) has a poor prognosis, and elucidating the molecular mechanisms involved in metastasis may lead to the development of novel therapeutic modalities. METHODS: Transcriptome analysis of surgically resected metastatic tissue from GC patients and noncancerous tissue was performed to identify novel metastasis-related genes. Analyses of in vitro cell function, apoptosis, the cell cycle and cancer stemness were performed using GC cell lines with a stable knockout of a candidate gene. In vivo percutaneous, peritoneal dissemination and liver metastasis xenograft models were also generated. PCR array and proteome analyses were performed. Expression of the candidate gene was analyzed in GC tissues from 300 patients. RESULTS: Lysosomal Associated Membrane Protein Family Member 5 (LAMP5) was upregulated in the metastatic tissues. LAMP5 knockout significantly suppressed proliferation, invasion, and migration of GC cells and increased apoptosis, cell cycle arrest and cancer stemness. LAMP5 knockout virtually suppressed tumor growth in in vivo percutaneous, peritoneal dissemination and liver metastasis models. EMT- and autophagy-related genes were associated with LAMP5. High LAMP5 mRNA levels were significantly associated with a worse prognosis. CONCLUSION: LAMP5 plays a vital role in metastasis formation and may be a promising novel target of drug development for metastatic GC in the future.

Composite hemangioendothelioma in the cervical spine with kaposiform hemangioendothelioma features in an elderly patient: a case report.

BACKGROUND: Composite hemangioendothelioma (CHE) is an intermediate group of tumors with features between hemangioma and angiosarcoma both histologically and biologically. CHE is predominant in young and middle-aged adults, but very infrequently affects the spine. We describe the case of primary CHE in the cervical spine exhibiting kaposiform hemangioendothelioma (KHE)-like components that was associated with cervical myelopathy with vertebral body destruction in an elderly woman. We retrospectively reviewed the case of a primary cervical spinal tumor, diagnosed as CHE with KHE-like components in pathological findings, associated with cervical myelopathy and cervical vertebral body destruction. CASE PRESENTATION: An 80-year-old woman presented with progressive cervical myelopathy caused by a cervical spine tumor. Preoperative cervical MRI revealed a neoplastic lesion invading the cervical spine that strongly compressed the spinal cord, causing right upper-limb paralysis. We performed partial tumor resection along with posterior decompression and fixation. Postoperatively, pathological findings showed that the tumor was CHE with KHE-like features. Following radiotherapy, no recurrences have been observed in 21 months. CONCLUSIONS: This is the first report of CHE with features of KHE in the spine of an elderly patient. Posterior decompression and fusion of the cervical spine and subsequent radiotherapy resulted in a good outcome.

The Impact of Medical Students Teaching Basic Life Support to Laypersons.

Basic life support (BLS) courses for laypersons, including cardiopulmonary resuscitation (CPR) training, is known to improve outcomes of out-of-hospital cardiac events. We asked medical students to provide BLS training for laypersons as a part of their emergency medicine education and evaluated the effects of training on the BLS skills of laypersons. We also used a questionnaire to determine whether the medical students who provided the BLS training were themselves more confident and motivated to perform BLS compared to students who did not provide BLS training. The proportions of laypersons who reported confidence in checking for a response, performing chest compressions, and automated external defibrillator (AED) use were significantly increased after the BLS training. The proportions of medical students who reported increased confidence/motivation in terms of understanding BLS, checking for a response, chest compression, use of AED, and willingness to perform BLS were significantly greater among medical students who provided BLS instructions compared to those who did not. BLS instruction by medical students was associated with an improvement in laypersons' CPR accuracy and confidence in responding to cardiac arrest. The results indicate that medical students could gain understanding, confidence, and motivation in regard to their BLS skills by teaching BLS to laypersons.

[Early Rehabilitation].

Bed rest after brain injury may result in disuse syndrome, making it difficult for the patient to reintegrate into society. Early mobilization and exercise intervention are important for preventing disuse syndrome and promoting early improvement of activities of daily living. However, there are problems with controlling the intracranial pressure and cerebral perfusion pressure after severe traumatic brain injury. Recently, the effect of rehabilitation for acute brain injury has been reported. Rehabilitation is a therapeutic approach to assist patients with disabilities in maintaining, improving, and regaining optimal functioning within their environments. In acute head injury cases, pulmonary rehabilitation and dysphagia rehabilitation are important in addition to exercise therapy. Although the evidence is not yet well established, it is important to provide early multidisciplinary rehabilitation to patients with traumatic brain injuries regularly. Moreover, rehabilitation needs to be conducted safely with adequate risk management. In the future, it is necessary to conduct a large-scale systematic cohort study on early rehabilitation to examine patient strength and the optimal time to begin exercising.

Therapeutic monoclonal antibody targeting of neuronal pentraxin receptor to control metastasis in gastric cancer.

BACKGROUND: Controlling metastasis is essential for improving the prognosis of patients with gastric cancer (GC). Here, we aimed to identify a molecule required for GC metastasis and to investigate its potential utility as a target for the development of therapeutic antibodies (Abs). METHODS: Transcriptome and bioinformatics analyses of human GC cell lines identified the neuronal pentraxin receptor (NPTXR) as a candidate molecule. NPTXR function was probed by modulating its expression in GC cells and assessing the effects on intracellular signaling and malignant behaviors in vitro and in mouse xenograft models. We also generated anti-NPTXR Abs and Nptxr-/- mice, and assessed the clinical significance of NPTXR expression in GC specimens. RESULTS: NPTXR mRNA expression in clinical specimens was associated with disease progression and was significantly higher in tissues from GC patients with distant metastasis compared with those without. NPTXR regulated expression of genes involved in metastatic behaviors as well as activation of the PI3K-AKT-mTOR, FAK-JNK, and YAP signaling pathways. NPTXR silencing promoted caspase-mediated apoptosis and attenuated GC cell proliferation, cell cycle progression, migration, invasion, adhesion, stem cell-like properties, and resistance to 5-fluorouracil in vitro, and also inhibited the tumorigenicity of GC cells in vivo. Anti-NPTXR Abs inhibited GC peritoneal metastasis in mice. Nptxr-/- mice showed no abnormalities in reproduction, development, metabolism, or motor function. CONCLUSIONS: NPTXR plays an essential role in controlling the malignant behavior of GC cells in vitro and in vivo. NPTXR-targeting Abs may thus have utility as novel diagnostic tools and/or treatment modalities for GC.

KCNJ15 Expression and Malignant Behavior of Esophageal Squamous Cell Carcinoma.

BACKGROUND: We aimed to clarify the role of potassium voltage-gated channel subfamily J member 15 (KCNJ15) in esophageal squamous cell carcinoma (ESCC) cells and its potential as a prognosticator in ESCC patients. METHODS: KCNJ15 transcription levels were evaluated in 13 ESCC cell lines and polymerase chain reaction (PCR) array analysis was conducted to detect coordinately expressed genes with KCNJ15. The biological functions of KCNJ15 in cell invasion, proliferation, migration, and adhesion were validated through small interfering RNA-mediated knockdown experiments. Cell proliferation was further evaluated through the forced expression experiment. KCNJ15 expression was detected in 200 ESCC tissues by quantitative real-time reverse transcription PCR (qRT-PCR) and analyzed in 64 representative tissues by immunohistochemistry. Correlations between KCNJ15 expression levels and clinicopathological features were also analyzed. RESULTS: The KCNJ15 expression levels varied widely in ESCC cell lines and correlated with COL3A1, JAG1, and F11R. Knockdown of KCNJ15 expression significantly repressed cell invasion, proliferation, and migration of ESCC cells in vitro. Furthermore, overexpression of KCNJ15 resulted in increased cell proliferation. Patients were stratified using the cut-off value of KCNJ15 messenger RNA (mRNA) levels in 200 ESCC tissues using receiver operating characteristic curve analysis; the high KCNJ15 expression group had significantly shorter overall and disease-free survival times. In multivariable analysis, high expression of KCNJ15 was identified as an independent poor prognostic factor. Staining intensity of in situ KCNJ15 protein expression tended to be associated with KCNJ15 mRNA expression levels. CONCLUSIONS: KCNJ15 is involved in aggressive tumor phenotypes of ESCC cells and its tissue expression levels may be useful as a prognosticator of patients with ESCC.

Accurate Risk Stratification of Patients with Node-Positive Gastric Cancer by Lymph Node Ratio.

BACKGROUND: We aimed to clarify the utility of lymph node ratio (LNR) for assessing the prognosis of patients with node-positive gastric cancer after curative gastrectomy. METHODS: We retrospectively analyzed data of 973 patients with node-positive gastric cancer who had undergone curative gastrectomy at nine institutions from 2010 to 2014. Survival analysis was performed by comparing LNR low and high groups according to the optimal cutoff value of LNR, which was determined using receiver operating characteristic curve analysis. RESULTS: LNR high was significantly associated with shorter disease-free survival and was an independent predictor of recurrence in all patients. Moreover, we obtained the similar results from analysis of each N stage. The prevalence of lymph node and peritoneal recurrence appeared to be higher in the LNR high group. Correlation analysis showed that LNR was negatively correlated with the number of retrieved nodes within every N stage; however, disease-free survival did not differ significantly between LNR low and high groups of each N stage with 16-30, 31-40, or >40 retrieved nodes. CONCLUSIONS: LNR is a strong prognostic factor and predictor of recurrence in patients with node-positive gastric cancer who have undergone curative gastrectomy. The combination of LNR and N staging permits more accurate prognostic stratification of patients with gastric cancer and may contribute to developing novel prognostic models.

Involvement of Gßγ subunits of Gi protein coupled with S1P receptor on multivesicular endosomes in F-actin formation and cargo sorting into exosomes.

Exosomes play a critical role in cell-to-cell communication by delivering cargo molecules to recipient cells. However, the mechanism underlying the generation of the exosomal multivesicular endosome (MVE) is one of the mysteries in the field of endosome research. Although sphingolipid metabolites such as ceramide and sphingosine 1-phosphate (S1P) are known to play important roles in MVE formation and maturation, the detailed molecular mechanisms are still unclear. Here, we show that Rho family GTPases, including Cdc42 and Rac1, are constitutively activated on exosomal MVEs and are regulated by S1P signaling as measured by fluorescence resonance energy transfer (FRET)-based conformational changes. Moreover, we detected S1P signaling-induced filamentous actin (F-actin) formation. A selective inhibitor of Gßγ subunits, M119, strongly inhibited both F-actin formation on MVEs and cargo sorting into exosomal intralumenal vesicles of MVEs, both of which were fully rescued by the simultaneous expression of constitutively active Cdc42 and Rac1. Our results shed light on the mechanism underlying exosomal MVE maturation and inform the understanding of the physiological relevance of continuous activation of the S1P receptor and subsequent downstream G protein signaling to Gßγ subunits/Rho family GTPases-regulated F-actin formation on MVEs for cargo sorting into exosomal intralumenal vesicles.

Extracellular α-synuclein drives sphingosine 1-phosphate receptor subtype 1 out of lipid rafts, leading to impaired inhibitory G-protein signaling.

α-Synuclein (α-Syn)-positive intracytoplasmic inclusions, known as Lewy bodies, are thought to be involved in the pathogenesis of Lewy body diseases, such as Parkinson's disease (PD). Although growing evidence suggests that cell-to-cell transmission of α-Syn is associated with the progression of PD and that extracellular α-Syn promotes formation of inclusion bodies, its precise mechanism of action in the extracellular space remains unclear. Here, as indicated by both conventional fractionation techniques and FRET-based protein-protein interaction analysis, we demonstrate that extracellular α-Syn causes expulsion of sphingosine 1-phosphate receptor subtype 1 (S1P1R) from the lipid raft fractions. S1P1R regulates vesicular trafficking, and its expulsion involved α-Syn binding to membrane-surface gangliosides. Consequently, the S1P1R became refractory to S1P stimulation required for activating inhibitory G-protein (Gi) in the plasma membranes. Moreover, the extracellular α-Syn also induced uncoupling of the S1P1R on internal vesicles, resulting in the reduced amount of CD63 molecule (CD63) in the lumen of multivesicular endosomes, together with a decrease in CD63 in the released exosomes from α-Syn-treated cells. Furthermore, cholesterol-depleting agent-induced S1P1R expulsion from the rafts also resulted in S1P1R uncoupling. Taken together, these results suggest that extracellular α-Syn-induced expulsion of S1P1R from lipid rafts promotes the uncoupling of S1P1R from Gi, thereby blocking subsequent Gi signals, such as inhibition of cargo sorting into exosomal vesicles in multivesicular endosomes. These findings help shed additional light on PD pathogenesis.

Cell biological profiling of reprogrammed cancer stem cell-like colon cancer cells maintained in culture.

Cancer stem cells (CSCs) are specific targets for therapeutic applications, but the rarity of CSCs within tumors makes the isolation of CSCs difficult. To overcome these problems, we generated CSCs in vitro using established reprogramming techniques. We transduced four previously established reprogramming factors, Oct3/4, Sox2, Klf4, and L-myc, into the colon cancer cell lines LoVo and OUMS-23, and investigated the biological characteristics of these lines. Tra-1-60+ cells were obtained from reprogrammed induced pluripotent stem (iPS) cell-like colonies and showed CSC properties, including colony formation, maintenance of colonies by repeated passages, and feeder cell dependency, as well as increased expressions of CSC markers such as CD133 and ALDH1. The CSC-like cells showed increased chemoresistance to 5-fluorouracil and elevated tumorigenicity upon transplantation into kidneys of immune-deficient mice. These tumors shifted to a poorly differentiated stage with many atypical cells, cytoplasmic mucin, and focal papillary components, with demonstrated dedifferentiation. The principal component analysis from DNA microarrays showed that though both cell lines moved to iPS cells after reprogramming, they were not completely identical to iPS cells. Significantly elevated gene expression of Decorin and CD90 was observed in CSC-like cells. Together, these results show that reprogramming of cancer cells produced not pluripotent stem cells but CSC-like cells, and these findings will provide biological information about genuine CSCs and help establish new CSC-targeted therapies.

A novel evaluation system for whole-organ-engineered liver graft by ex vivo application to a highly reproducible hepatic failure rat model.

In recent years, studies on liver graft construction using the decellularized liver as a template for transplantation therapy have attracted much attention. However, the therapeutic effect of constructed liver grafts in hepatic failure has not been evaluated. Therefore, we aimed to develop a novel evaluation system demonstrating the curative effect of a constructed liver graft in animals with hepatic failure. First, we developed a highly reproducible rat model of hepatic failure by combining 80% partial hepatectomy with warm ischemia. In this model, severity could be controlled by the warm ischemic period. We also constructed a liver graft by recellularization of decellularized liver, and confirmed the ammonia metabolic function in the graft in vitro as one of the most important functions for recovery from hepatic failure. The graft was then applied to our developed hepatic failure rat model using a blood extracorporeal circulation system. In this application, the graft metabolized the ammonia in the blood of animals with hepatic failure and was thus suggested to be effective for the treatment of hepatic failure. In summary, a novel evaluation system for whole-organ-engineered liver graft as a preliminary stage of transplantation was developed. This system was expected to provide much information about the curative effect of a constructed liver graft.

Alignment factors affecting the medial meniscus extrusion increases the risk of osteoarthritis development.

PURPOSE: Varus alignment is known as one of the major causes of medial compartment osteoarthritis (OA). Medial meniscus extrusion also plays a critical role in the in the development of OA. However, studies on the exact relationship between alignment parameters and medial meniscus extrusion are limited. Therefore, this study aimed to investigate this relationship in patients with knee OA. METHODS: Based on a retrospective analysis of the outpatient magnetic resonance imaging (MRI) database, 190 knees were identified to be examined using weight-bearing, whole-leg radiographs and MRIs within 3 months from the first consultation. Subsequently, various parameters of lower leg alignment were measured, which affected the knee varus in radiographs. Finally, a statistical analysis was performed to assess the relationships between the OA grade, distance of medial meniscus extrusion (MME), and alignment parameters; hip-knee-ankle angle (HKAA), percentage of mechanical axis (% MA), medial proximal tibial angle (MPTA), and joint line convergence angle (JLCA). The subjects were divided according to the presence or absence of MME (Group A: MME distance below 3 mm, Group B: MME distance 3 mm and above) to assess the differences in each alignment parameter correlated with MME distance between the groups. RESULTS: MME distance significantly increased with OA grade progression. HKAA, % MA, MPTA, and JLCA significantly correlated with medial meniscus extrusion distance (r = - 0.21, - 0.23, - 0.16, 0.3, respectively). Multiple regression analysis of each significant alignment combined with age, sex, and body mass index revealed that HKAA, % MA, MPTA, and JLCA were significant independent factors of MME distance (P = 0.008, 0.0026, 0.011, 0.0001, respectively). These significant findings were reinforced in group B. In contrast, the correlation between alignment parameters and medial meniscus extrusion distance was not significant in group A. CONCLUSION: Varus alignment factors are related to MME distance especially in extruded meniscus knees, as the OA grade progressed. Therefore, the coexistence of varus alignment and MME can be the risk factors for OA progression. As the low MPTA was an independent alignment factor for generating varus alignment, patients with osteoarthritis of the knee with both, low MPTA and MME could be the appropriate candidates for early intervention by high tibial osteotomy. LEVEL OF EVIDENCE: III.

The exploration of population pharmacokinetic model for meropenem in augmented renal clearance and investigation of optimum setting of dose.

In recent years, augmented renal clearance (ARC), in which renal function is excessively enhanced, has been reported, and its influence on ß-lactam antibiotics has been investigated. In this study, we aimed to determine the optimum population pharmacokinetic model of meropenem in patients with sepsis with ARC, and evaluated dosing regimens based on renal function. Seventeen subjects (6 with ARC and 11 without) were enrolled in this study. Predicted meropenem concentrations were evaluated for bias and precision using the Bland-Altman method. To examine the dosing regimen, Monte Carlo simulation was performed to calculate the cumulative fraction of response (CFR). In patients with ARC, the bias (average of the predicted value and measured value residuals) of models constructed by Crandon et al. (2011), Roberts et al. (2009), and Jaruratanasirikul et al. (2015) were 5.96 µg/mL, 10.91 µg/mL, and 4.41 µg/mL, respectively. Following 2 g meropenem every 8 h (180 min infusion), CFR ≥ 90%, a criterion of success for empirical therapy, was achieved, even with creatinine clearance of 130-250 mL/min. For patients with sepsis and ARC, the model of Jaruratanasirikul et al. showed the highest degree of accuracy and precision and confirmed the efficacy of the meropenem dosing regimen in this patient population.

Clinical course of the bony lesion of single-system single-site Langerhans cell histiocytosis - Is appropriate follow-up sufficient treatment?

BACKGROUND: Langerhans cell histiocytosis (LCH) is categorized into three types, which include single-system single-site (SS-s), single-system multiple-site (SS-m) and multisystem (MS). The most commonly affected site in LCH is bone, and the bony lesion of SS-s LCH has a good prognosis. The bony lesion of SS-s LCH has been thought to regress spontaneously. Although treatments such as curettage, direct injection of corticosteroids, and chemotherapy have been performed, regular follow-up is the first line of treatment for the bony lesion of SS-s LCH. For preventing orthopedic sequelae, strict and appropriate follow-up should be performed, but the appropriate period and method of follow-up has not yet been established. METHODS: In the present study, we retrospectively analyzed a series of 7 cases of patients with SS-s LCH with a bony lesion treated in the Department of Orthopedic Surgery at Kagoshima University Hospital (Kagoshima, Japan) from 2006 to 2015. RESULTS: The bony lesion regressed spontaneously in all patients. Factors such as location, size, preoperative C-reactive protein (CRP) value, standardized uptake (SUV) value of positron emission tomography (PET), age, sex and direct steroid injection were not related to the clinical course. Temporary expansion of the lesion occurred in 3 patients and a temporary worsening of pain occurred in 1 patient during the follow-up period. These events occurred within 6 weeks after biopsy. CONCLUSION: Careful follow-up and the use of an appropriate orthosis can lead to a good clinical course for the bony lesion of SS-s LCH. Future research should seek to determine the appropriate follow-up period.

Giant Cell Tumor of the Distal Phalanx of the Fourth Toe: A Case Report.

Giant cell tumor of the bone is a benign, but locally aggressive, primary bone tumor of unknown origin. It most commonly occurs in the long bones and is only rarely found in the phalangeal bones, such as the distal phalanx of the foot. In our review of English-language published studies, only 4 other cases of giant cell tumor involving the distal phalangeal bone of the foot had been reported to date. We report a case of giant cell tumor arising in the distal phalanx of the fourth toe in a 28-year-old female. Although bisphosphonate therapy was administered, the tumor showed highly aggressive behavior with ulceration of the overlying skin, and the patient underwent phalangeal amputation 1.5 months after diagnosis.

GLI2 is a novel therapeutic target for metastasis of osteosarcoma.

Aberrant activation of the Hedgehog (Hh) pathway has been reported in several malignancies. We previously demonstrated that knockdown of GLI2 inhibited proliferation of osteosarcoma cells through regulation of the cell cycle. In this study, we analyzed the function of GLI2 in the pathogenesis of osteosarcoma metastasis. Immunohistochemical studies showed that GLI2 was overexpressed in patient osteosarcoma specimens. Knockdown of GLI2 inhibited migration and invasion of osteosarcoma cells. In contrast, the forced expression of constitutively active GLI2 in mesenchymal stem cells promoted invasion. In addition, xenograft models showed that knockdown of GLI2 decreased lung metastasis of osteosarcomas. To examine clinical applications, we evaluated the efficacy of arsenic trioxide (ATO), which is a Food and Drug Administration-approved antitumor drug, on osteosarcoma cells. ATO treatment suppressed the invasiveness of osteosarcoma cells by inhibiting the transcriptional activity of GLI2. In addition, the combination of Hh inhibitors including ATO, vismodegib and GANT61 prevented migration and metastasis of osteosarcoma cells. Consequently, our findings suggested that GLI2 regulated metastasis as well as the progression of osteosarcomas. Inhibition of the GLI2 transcription may be an effective therapeutic method for preventing osteosarcoma metastasis.