Differential expression of the epithelial mesenchymal transition factors Snail, Slug, Twist, TGF-β, and E-cadherin in ameloblastoma

TGF-β Signaling in Progression of Oral Cancer

Oral cancer is a common malignancy worldwide, accounting for 1.9% to 3.5% of all malignant tumors. Transforming growth factor β (TGF-β), as one of the most important cytokines, is found to play complex and crucial roles in oral cancers. It may act in a pro-tumorigenic and tumor-suppressive manner; activities of the former include cell cycle progression inhibition, tumor microenvironment preparation, apoptosis promotion, stimulation of cancer cell invasion and metastasis, and suppression of immune surveillance. However, the triggering mechanisms of these distinct actions remain unclear. This review summarizes the molecular mechanisms of TGF-β signal transduction, focusing on oral squamous cell and salivary adenoid systemic carcinomas as well as keratocystic odontogenic tumors. Both the supporting and contrary evidence of the roles of TGF-β is discussed. Importantly, the TGF-β pathway has been the target of new drugs developed in the past decade, some having demonstrated promising therapeutic effects in clinical trials. Therefore, the achievements of TGF-β pathway-based therapeutics and their challenges are also assessed. The summarization and discussion of the updated knowledge of TGF-β signaling pathways will provide insight into the design of new strategies for oral cancer treatment, leading to an improvement in oral cancer outcomes.

Immunohistochemical expression of E-cadherin, N-cadherin and Snail/slug in ameloblastoma

CONTEXT

Ameloblastoma is the most common odontogenic tumour and its histomorphological distinction into growth patterns and variants, does not accurately convey information about its biologic aggressiveness. Expression of epithelial mesenchymal transition (EMT) markers, which have been implicated in its etiogenesis, might assist in delineating aggressiveness across variants. This may help in formulating appropriate treatment modalities for its management AIMS: To determine expression of SNAIL/SLUG and ECAD/NCAD in tumour cells in clinical and histological subtypes of ameloblastoma and to establish any association between the immunostaining profile and the biologic behaviour of histologic types of ameloblastoma.

SETTINGS/DESIGN

This is a retrospective study conducted to evaluate the immunoprofile of selected clinical subtypes and histological variants to EMT factors via immunostaining to SLUG and ECAD/NCAD antibodies. Mean aggregate scores for each antibody per variant was analyzed using ANOVA or Kruskal-Wallis test when appropriate. Agreement between AR and SR regions was correlated using Spearman's correlation co-efficient.

RESULTS

A higher staining SLUG intensity in the stellate reticulum (SR) like areas relative to the ameloblast like areas (AR) was observed, without concomitant E-cadherin repression or elimination. However, a direct relationship between SLUG and N-cadherin was observed.

CONCLUSION

Expression of SLUG in the SR like areas can be utilized to predict the biologic behavior of specific clinico-histological variants, however its mechanism via alterations in cadherin switching is equivocal.

Low-Dose X-Ray Increases Paracellular Permeability of Human Renal Glomerular Endothelial Cells

Objective

Glomerular endothelium functions as a filtration barrier of metabolites in the kidney. Although X-ray irradiation modulated the permeability of the vascular endothelium, the response of human renal glomerular endothelial cells (HRGECs) to low-dose X-ray irradiation has not been investigated. We evaluated the impacts of low-dose X-ray irradiation on HRGECs and revealed the underlying mechanism.

Methods

HRGECs were exposed to X-ray with doses of 0, 0.1, 0.5, 1.0, and 2.0 Gy. The proliferation, viability, and apoptosis of HRGECs were examined by MTT assay, trypan blue staining assay, and TUNEL staining, respectively. The paracellular permeability was assessed by paracellular permeability assay. The expression of VE-cadherin was investigated via immunofluorescence assay. Western blot and qRT-PCR detected the expression levels of VE-cadherin and CLDN5. Besides, the expression levels of pVE-cadherin (pY658), TGF-β, TGF-βRI, Src, p-Src, Smad2, p-Smad2, Smad3, p-Smad3, SNAIL, SLUG, and apoptosis-related proteins were tested by Western blot.

Results

The proliferation, viability, and apoptosis of HRGECs were not affected by low-dose (<2.0 Gy) X-ray irradiation. X-ray irradiation dose-dependently reduced the level of VE-cadherin, and VE-cadherin and CLDN5 levels were reduced with X-ray irradiation. The levels of pY658, p-Src, p-Smad2, and p-Smad3 were upregulated with the increase in X-ray dose. Besides, the paracellular permeability of HRGECs was increased by even low-dose (<2.0 Gy) X-ray irradiation. Therefore, low-dose X-ray irradiation reduced the cumulative content of VE-cadherin and increased the level of pY658 via activation of the TGF-β signaling pathway.

Conclusion

Even though low-dose X-ray exposure had no impact on proliferation, viability, and apoptosis of HRGECs, it increased the paracellular permeability by deterioration and downregulation of VE-cadherin through stimulating the TGF-β signaling pathway. This study built the framework for kidney response to low-dose irradiation exposure.

Identification of key biomarkers related to epithelial-mesenchymal transition and immune infiltration in ameloblastoma using integrated bioinformatics analysis

OBJECTIVE

This study aimed to elucidate the underlying mechanisms of ameloblastoma (AM) through integrated bioinformatics analysis.

METHODS

We downloaded two microarrays of AMs from the GEO database and identified differentially expressed genes (DEGs) by integrated bioinformatics analysis. The enrichment analysis of DEGs was conducted to characterize GO and KEGG pathways. Protein-protein interaction (PPI) network and hub genes were screened via STRING and Cytoscape. CIBERSORT algorithm was utilized to analyze immune infiltration in AMs. We also verified the diagnostic and therapeutic value of hub genes.

RESULTS

Overall, 776 DEGs were identified in AMs through bioinformatics analysis. The function enrichment analysis shed light on pathways involved in AMs. Subsequently, we screened six hub genes via PPI network. Furthermore, we evaluated immune infiltration in AMs and found that macrophages may be participating in the progression of AMs. The upregulated expression of FN1 was related to the macrophages M2 polarization. Finally, ROC analysis indicated that six hub genes had high diagnostic value for AMs and 11 drugs interacted with upregulated hub genes were identified by screening the DGIdb database.

CONCLUSION

This study revealed the underlying mechanisms of pathogenesis and biological behavior of AMs and provided candidate targets for the diagnosis and treatment of AMs.

Piperine inhibits AML-12 hepatocyte EMT and LX-2 HSC activation and alleviates mouse liver fibrosis provoked by CCl4: roles in the activation of the Nrf2 cascade and subsequent suppression of the TGF-β1/Smad axis

Piperine (PIP) is an alkaloid derived from peppercorns. Herein, we assessed its effects on hepatocyte EMT and HSC activation in vitro and CCl₄-elicited liver fibrosis in mice. Further experiments were performed to unveil the molecular mechanisms underlying the hepatoprotective activity of PIP. We found that PIP inhibited TGF-β1-provoked AML-12 hepatocyte EMT and LX-2 HSC activation. Mechanistically, in AML-12 and LX-2 cells, PIP evoked Nrf2 nuclear translocation and increased transcriptions of Nrf2-responsive antioxidative genes. These events decreased TGF-β1-induced production of ROS. Moreover, PIP increased the expression of Smad7, suppressed phosphorylation and nuclear translocation of Smad2/3, and decreased the transcriptions of Smad2/3-downstream genes. Knockdown of Nrf2 abrogated the protective activity of PIP against TGF-β1. Modulatory effects of PIP on the TGF-β1/Smad cascade were also crippled, which suggested that activation of Nrf2 played critical roles in the regulatory effects of PIP on TGF-β1/Smad signaling. Experiments in vivo unveiled that PIP ameliorated mouse liver fibrosis provoked by CCl₄. PIP modulated the intrahepatic contents of the markers of EMT and HSC activation. In mouse livers, PIP activated Nrf2 signaling and reduced Smad2/3-dependent gene transcriptions. Our findings collectively suggested PIP as a new chemical entity with the capacity of alleviating liver fibrosis. The activation of the Nrf2 cascade and subsequent suppression of the TGF-β1/Smad axis are implicated in the hepatoprotective activity of PIP.

TPM3 mediates epithelial-mesenchymal transition in esophageal cancer via MMP2/MMP9

Background

Esophageal cancer (EC) is a malignant tumor with high mortality. Correlations have been found between the expression level of tropomyosin 3 (TPM3) and the depth of tumor invasion, lymph node metastasis, and the 5-year survival rate. However, the specific mechanisms underlying EC remain unclear.

Methods

Stably transfected TPM3-overexpresing and TPM3-knockdown esophageal squamous cell carcinoma (ESCC) cell lines (ECa109 and EC9706) were constructed, and the association between TPM3 and the proliferation, invasion, and migration of ESCC was investigated using molecular biology methods. The associations between TPM3 and matrix metalloproteinase (MMP)2/9 or epithelial-mesenchymal transition (EMT)-related proteins were verified, and the potential tumor-promoting mechanism was explored by Gelatin Zymography Experiment.

Results

TPM3 was found to promote the proliferation, migration, and metastatic potential of ESCC in vivo and in vitro, and stimulate the expression of MMP2/9 and certain EMT markers other than E-cadherin. The replenishment of MMP2/9 restored the malignant behavior of ESCC caused by TPM3. A gelatinase assay showed that the expression of TPM3 was related to the activity of MMP9.

Conclusions

TPM3 promoted proliferation, migration, and metastatic potential in EC cells. Additionally, TPM3 promoted the EMT process. This function may be achieved via the regulation the expression of MMP2/9.

Pathogenesis and characteristics of large ameloblastoma of the jaw: a report of two rare cases

Ameloblastoma is a common odontogenic epithelial tumor that exhibits various biological behaviors, ranging from simple cystic expansion to aggressive solid masses characterized by local invasiveness, a high risk of recurrence, and even malignant transformation. We report on two cases of unusually large solid ameloblastomas. We detected epithelial–mesenchymal transition-related gene expression and HRAS gene single nucleotide polymorphisms, providing possible molecular evidence of mesenchymal morphological changes in ameloblastoma. The detailed analysis of the pathogenesis of these two cases of ameloblastoma may deepen our understanding of this rare disease and offer promising targets for future targeted therapy.

MicroRNA-1-3p Suppresses Malignant Phenotypes of Ameloblastoma Through Down-Regulating Lysosomal Associated Membrane Protein 2-Mediated Autophagy

Objective: Several clinical trials have suggested that autophagy inhibition is a promising approach for cancer therapy. However, the implications of autophagy in ameloblastoma (AB) remain undiscovered. This study investigated the dysregulated autophagy and its regulatory mechanisms in AB.

Methods: The expression and distribution of autophagy-related proteins including B-cell lymphoma-2-interacting protein-1 (Beclin1), microtubule-associated protein 1 light chain 3 (LC3) II/I and lysosomal associated membrane protein 2 (LAMP2) were detected in AB and normal oral mucosa (NOM) tissues by immunohistochemistry and western blot analyses. Under transmission electron microscopy, the autophagy of AB was observed. LAMP2 was a potential target mRNA of miR-1-3p. Quantitative Real-time PCR (qRT-PCR) analysis was utilized for examining LAMP2 and miR-1-3p in AB tissues as well as AM-1 cells. The correlation between LAMP2 and miR-1-3p was analyzed in AB. After transfection with miR-1-3p mimic or inhibitor, LAMP2 expression, proliferation, migration, and invasion were separately detected in AM-1 cells. Rescue assays were finally presented.

Results: Our results showed that Beclin1 was lowly expressed as well as LC3II/I and LAMP2 were highly expressed in AB. Autophagosomes were observed in AB. MiR-1-3p was lowly expressed in AB, which exhibited negative correlations to LAMP2 expression. MiR-1-3p up-regulation significantly lowered LAMP2 expression in AM-1 cells. Furthermore, miR-1-3p overexpression restrained proliferative, migrated, and invasive capacities of AM-1 cells, which were ameliorated by LAMP2 overexpression.

Conclusion: Our findings demonstrated that miR-1-3p suppressed malignant phenotypes of AB through down-regulating LAMP2-mediated autophagy, which could become an underlying target for AB therapy.

Insight into the molecular pathogenesis of odontogenic lesions

BACKGROUND

Odontogenic tumors, derived from epithelial, ectomesenchymal, and/or mesenchymal elements of the tooth-forming apparatus, constitute a heterogeneous group of lesions, including hamartomas, benign and malignant neoplasms with metastatic capabilities.

HIGHLIGHT

This review provides a comprehensive overviewof the pathogenesis of odontogenic tumors and explains the associated molecular events in the context of hallmarks of cancer established by Hanahan D and Weinberg RA. Diagrammatic representations depicted in the article would facilitate easier understanding.

CONCLUSION

A better understanding of the pathogenesis of the lesions may assist in determining patient's prognosis and devising better targeted therapeutic treatment, thus, reducing the morbidity and mortalityof patients.

An integrative analysis of genome-wide methylation and expression in ameloblastoma: A pilot study

OBJECTIVE

DNA methylation regulates the expression of various genes involved in tumorigenesis. Ameloblastoma is a benign odontogenic jaw tumor. It is locally aggressive with a high level of recurrence. A delay in treatment can lead to severe facial disfigurement. To the best of our knowledge, this is the first integrated analysis of DNA methylation and gene expression in ameloblastoma with the aim to identify genes that may be regulated by DNA methylation.

MATERIALS AND METHODS

We used an Infinium MethylationEPIC array to measure genome-wide methylation and the Illumina HiSeq platform to obtain gene expression data in ameloblastoma tissues from five patients and dental follicles from three healthy subjects. An integration analysis was performed using City of Hope CpG Island Analysis Pipeline software.

RESULTS

We identified 25,255 differentially methylated CpG sites and 17 differentially methylated CpG islands; six of the islands were negatively correlated with the expression of BAIAP2, DUSP6, FGFR2, FOXF2, NID2, and PAK6. Pyrosequencing and immunostaining techniques were further used to validate FGFR2, NID2, and PAK6.

CONCLUSIONS

This analysis identifies a group of novel genes that may be regulated by DNA methylation and will possibly lead to new insights into the pathology and invasion mechanism of ameloblastoma.

MMP-7, -8, -9, E-cadherin, and beta-catenin expression in 34 ameloblastoma cases

Objectives

Ameloblastoma is a benign, locally aggressive odontogenic tumor with high recurrence rates. Matrix metalloproteinases (MMPs) mediate extracellular integrity in normal and pathological conditions, and exert multiple functions coordinating inflammation and tumor progression. E‐cadherin and beta‐catenin are adherence junction molecules in cell‐to‐cell connections. We investigated the involvement of MMP‐7, ‐8, ‐9, E‐cadherin, and beta‐catenin in ameloblastoma and the surrounding extracellular matrix.

Material and methods

Our material consisted of 30–34 tissue samples from ameloblastoma patients of Helsinki University Hospital. We used immunohistochemistry to detect the expression of the biomarkers. Two oral pathologists independently scored the immunoexpression intensities and statistical calculations were made based on the results.

Results

E‐cadherin expression was weaker in the maxillary than in mandibular ameloblastomas. Beta‐catenin was expressed in the ameloblastoma cell membranes. We detected MMP‐8 and ‐9 expression in polymorphonuclear neutrophils in the extracellular area and these MMPs correlated positively with each other. Osteoclasts lining bone margins and multinuclear giant cells expressed MMP‐9. Neither MMP‐8 nor MMP‐9 immunoexpression could be detected in ameloblastoma cells. MMP‐7 expression was seen in some apoptotic cells.

Conclusion

The fact that E‐cadherin immunoexpression was weaker in maxillary compared to mandibular ameloblastomas might associate to earlier recurrences. It promotes the idea of mandibular and maxillary ameloblastoma exerting differences in their biologies. We detected MMP‐8 and ‐9 in polymorphonuclear neutrophils which relates to these MMPs participating in extracellular remodeling through a mild inflammatory process. Bone degradation around ameloblastoma may be due to MMP‐9 in osteoclasts but this phenomenon might be an independent process and needs further investigations.

Effects of butyric acid, a bacterial metabolite, on the migration of ameloblastoma mediated by laminin 332

Ameloblastoma is a benign tumor that develops in the jawbone. Occasionally, however, it may become malignant and metastasize to other tissues. Although it has been suggested that various cytokines and several adhesion factors may play a role in its malignant transformation, the details have not been elucidated. In this context, it has been reported that butyric acid produced by periodontopathic bacteria causes progression of malignant tumors occurring in the mouth via podoplanin. However, the influence of butyric acid on ameloblastoma has not been clarified. In the present study, therefore, the expression of various cytokines and adhesion factors in ameloblastoma upon stimulation with butyric acid or cytokines was investigated using real-time reverse-transcription polymerase chain reaction. Three cell lines (HAM1, HAM2 and HAM3) established from the same ameloblastoma were used in the experiments. It was found that the expression of mRNAs for epidermal growth factor (EGF) and transforming growth factor beta 1 (TGFβ1) was increased in HAM2 and HAM3, respectively, upon stimulation with butyric acid. In addition, stimulation with EGF and TGFβ1 led to an increase in the expression of laminin β-3 mRNA in the respective cell lines. These results suggest that butyric acid may be involved in ameloblastoma exacerbation through the expression of laminin 332 (LM332) via EGF and TGFβ1 produced by ameloblastoma itself.

Ameloblastoma cell lines derived from different subtypes demonstrate distinct developmental patterns in a novel animal experimental model

Objective

Ameloblastoma is a representative odontogenic tumor comprising several characteristic invasive forms, and its pathophysiology has not been sufficiently elucidated. A stable animal experimental model using immortalized cell lines is crucial to explain the factors causing differences among the subtypes of ameloblastoma, but this model has not yet been disclosed. In this study, a novel animal experimental model has been established, using immortalized human ameloblastoma-derived cell lines.

Methodology

Ameloblastoma cells suspended in Matrigel were subcutaneously transplanted into the heads of immunodeficient mice. Two immortalized human ameloblastoma cell lines were used: AM-1 cells derived from the plexiform type and AM-3 cells derived from the follicular type. The tissues were evaluated histologically 30, 60, and 90 days after transplantation.

Results

Tumor masses formed in all transplanted mice. In addition, the tumors formed in each group transplanted with different ameloblastoma cells were histologically distinct: the tumors in the group transplanted with AM-1 cells were similar to the plexiform type, and those in the group transplanted with AM-3-cells were similar to the follicular type.

Conclusions

A novel, stable animal experimental model of ameloblastoma was established using two cell lines derived from different subtypes of the tumor. This model can help clarify its pathophysiology and hasten the development of new ameloblastoma treatment strategies.

Upregulation of Neural Cell Adhesion Molecule 1 (NCAM1) by hsa-miR-141-3p Suppresses Ameloblastoma Cell Migration

Background

Neural cell adhesion molecule 1 (NCAM1; CD56) and E-cadherin are both involved in cell-cell adhesion and cell development processes, and their dysregulation is associated with various tumors. We hypothesized that dysregulated NCAM1 could suppress the invasive behavior of ameloblastoma (AB), and its expression was regulated by miR-141-3p.

Material/Methods

Real-time qPCR was performed to examine differences in miR-141-3p expression between AB tissues and normal oral tissues (NOMs). The potential target NCAM1 of miR-141-3p was predicted by bioinformatics analysis, which was validated through dual-luciferase assay. The mRNA and protein levels of NCAM1 were detected by real-time qPCR and Western blot, respectively. Furthermore, the expression and distribution of NCAM1 in AB were investigated through immunohistochemical staining, and immunohistochemical staining of E-cadherin was also performed. After overexpression of NCAM1, the migration of AM-1 cells was examined using wound-healing assay.

Results

Real-time qPCR results confirmed that miR-141-3p was significantly downregulated in AB tissues. According to bioinformatics analysis, NCAM1 was a target of miR-141-3p, which was confirmed by dual luciferase assay. We found that NCAM1 was significantly upregulated in AB tissues at the mRNA and protein levels. Furthermore, NCAM1 and E-cadherin were mainly expressed on the cell membrane of AB. Downregulation of E-cadherin was found in AB tissues. As shown in wound-healing assay results, NCAM1 overexpression significantly inhibited the invasiveness of AM-1 cells.

Conclusions

In this study, highly expressed NCAM1 was found in AB, and it suppressed the migration of AB cells and was regulated by miR-141-3p, suggesting its potential value as a therapeutic target for AB.

Tumor-Derived Exosomes Mediate the Instability of Cadherins and Promote Tumor Progression

Cadherins, including E-cadherin, N-cadherin, VE-cadherin, etc., are important adhesion molecules mediating intercellular junctions. The abnormal expression of cadherins is often associated with tumor development and progression. Epithelial–mesenchymal transition (EMT) is the most important step in the metastasis cascade and is accompanied by altered expression of cadherins. Recent studies reveal that as a cargo for intercellular communication, exosomes—one type of extracellular vesicles that can be secreted by tumor cells—are involved in a variety of physiological and pathological processes, especially in tumor metastasis. Tumor-derived exosomes play a crucial role in mediating the cadherin instability in recipient cells by transferring bioactive molecules (oncogenic microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), EMT-related proteins, and others), modulating their local and distant microenvironment, and facilitating cancer metastasis. In turn, aberrant expression of cadherins in carcinoma cells can also affect the biogenesis and release of exosomes. Therefore, we summarize the current research on the crosstalk between tumor-derived exosomes and aberrant cadherin signals to reveal the unique role of exosomes in cancer progression.

Epithelial-to-mesenchymal transition in ameloblastoma: focus on morphologically evident mesenchymal phenotypic transition

The ameloblastoma is the most common and clinically significant odontogenic epithelial neoplasm known for its locally-invasive behaviour and high recurrence risk. Epithelial-to-mesenchymal transition (EMT) is a fundamental process whereby epithelial cells lose their epithelial characteristics and gain mesenchymal properties. EMT induction via transcription repression has been investigated in ameloblastoma. However, morphologically evident mesenchymal phenotypic transition remains ill-defined. To determine this, 24 unicystic (UA), 34 solid/multicystic (SA) and 18 recurrent ameloblastoma (RA) were immunohistochemically examined for three EMT-related mesenchymal markers, alpha smooth muscle actin (α-SMA), osteonectin and neuronal cadherin (N-cadherin). All three factors were heterogeneously detected in ameloblastoma samples (α-SMA, n=71/76, 93.4%; osteonectin, n=72/76, 94.7%; N-cadherin, n=24/76, 31.6%). In the tumoural parenchyma, immunoreactive cells were not morphologically distinct from their non-reactive cellular counterparts. Rather, α-SMA and osteonectin predominantly labelled the cytoplasm of central polyhedral > peripheral columnar/cuboidal tumour cells. N-cadherin demonstrated weak-to-moderate circumferential membranous staining in both neoplastic cell types and cytoplasmic expression in spindle-celled epithelium of desmoplastic amelobastoma. For all tumour subsets, α-SMA and osteonectin scored significantly higher in the stroma > parenchyma whilst α-SMA was overexpressed along the tumour invasive front > centre (p<0.05). Stromal N-cadherin scored higher in SA > UA and RA > UA (p<0.05). Other clinicopathological parameters showed no significant associations. Taken together, acquisition of mesenchymal traits without morphologically evident mesenchymal alteration suggests partial EMT in ameloblastoma. Stromal upregulation of these proteins in SA and RA implicates a role in local invasiveness.

Liver fibrosis in biliary atresia

BACKGROUND

Biliary atresia (BA) is the most common cause of obstructive jaundice in infants. Although the Kasai procedure has greatly improved the prognosis, most patients still need liver transplantation (LT) for long-term survival. The pathogenesis of BA has not been fully clarified, and liver fibrosis in BA is far beyond biliary obstructive cirrhosis.

DATA SOURCES

Literature reviews were underwent through PubMed. Persistent inflammation, immune response, biliary epithelial-mesenchymal transition, matrix deposition, decompensated angiogenesis, and unique biliary structure development all contribute to the fibrosis process. Observed evidences in such fields have been collected and form the backbone of this review.

RESULTS

Interactions of the multiple pathways accelerate this process.

CONCLUSIONS

Understanding the mechanisms of the liver fibrosis in BA may pave the way to improved survival after the Kasai procedure.

MDM2 promotes epithelial-mesenchymal transition through activation of Smad2/3 signaling pathway in lung adenocarcinoma

Background

Mouse double minute 2 (MDM2) contributes to cancer metastasis and epithelial-mesenchymal transition (EMT). This study aimed to investigate small mothers against decapentaplegic (Smad) signaling in MDM2-mediated EMT in lung adenocarcinoma (LAC).

Materials and methods

Expression patterns of MDM2 in LAC tissues, adjacent tissues, and cell lines (BEAS-2B, PC9, H1975, and A549) were detected. We then overexpressed MDM2 in PC9 cells and knocked it down in H1975 cells. To explore whether MDM2 activates EMT through the Smad2/3 signaling pathway, Smad2 and Smad3 were also silenced by siRNA in H1975 cells. Male BALB/c nude mice were used in in vivo model to validate the effects of MDM2 on LAC cells.

Results

MDM2 was significantly upregulated in LAC tissues compared with adjacent tissues. The expression of MDM2 was relatively higher in PC9 cells and relatively lower in H1975 cells compared with A549 cells. Overexpression of MDM2 significantly increased cell proliferation, migration, and invasion in LAC cells, while inhibiting apoptosis in PC9 cells. On the contrary, silencing of MDM2 significantly inhibited the expression of EMT-related genes N-cadherin and vimentin, while promoting the expression of E-cadherin and β-catenin. In vivo, MDM2 knockdown inhibited tumor growth. In addition, the expression of Smad2/3 was correlated with MDM2 in H1975 cells transfected with Smad2 and Smad3 siRNAs, which inhibited EMT progress.

Conclusion

MDM2 can activate the Smad2/3 signaling pathway, which promotes the proliferation and EMT progress of LAC cells.

Mutational Signatures in Mandibular Ameloblastoma Correlate with Smoking

Ameloblastoma is a rare tumor of odontogenic epithelium, the low incidence rate of which precludes statistical determination of its molecular characterizations. Despite recent genomic and transcriptomic profiling, the etiology of ameloblastomas remains poorly understood. Risk factors of ameloblastoma development are also largely unknown. Whole exome sequencing was performed on 11 mandibular ameloblastoma samples. We identified 2 convergent mutational signatures in ameloblastoma: 1) a signature found in multiple types of lung cancers with probable etiology of tobacco carcinogens (COSMIC signature 4) and 2) a signature present in gingivobuccal oral squamous cell carcinoma and correlated with tobacco-chewing habits (COSMIC signature 29). These mutational signatures highlight tobacco usage or related mutagens as one possible risk factor of ameloblastoma, since the association of BRAF mutations and smoking was demonstrated in multiple studies. In addition to BRAF hotspot mutations (V600E), we observed clear inter- and intratumor heterogeneities. Interestingly, prior to BRAF mutation, important genes regulating odontogenesis mutated (e.g., corepressor BCOR), possibly playing important roles in tumorigenesis. Furthermore, recurrent mutations in the CDC73 gene, the germline mutations of which predispose patients to the development of jaw tumors, were found in 2 patients, which may lead to recurrence if not targeted by therapeutic drugs. Our unbiased profiling of coding regions of ameloblastoma genomes provides insights to the possible etiology of mandibular ameloblastoma and highlights potential disease risk factors for screening and prevention, especially for Asian patients. Because of the limited sample size and incomplete habitual, dietary, and occupational data, a causal link between tobacco usage and ameloblastoma still requires further investigations.

Epithelial to mesenchymal transition is involved in ethanol promoted hepatocellular carcinoma cells metastasis and stemness

Hepatocellular Carcinoma (HCC) is a malignant tumor with high rate of relapse and metastasis. Ethanol is a well-known risk factor for HCC; it promotes the progression and aggressiveness of HCC. However, the underlying mechanism remains unclear. In clinic studies, we showed that alcohol consumption is positively correlated with TNM stage and vessel invasion; HCC patients with chronic drinking history had faster progression rate and poorer prognosis compared to non-drinkers. In experimental models, ethanol exposure enhanced the metastasis, and invasion of HCC cells. Ethanol exposure increased cancer stem cells (CSC) population and enhanced stemness of HCC cells in vitro and in vivo. Mechanically, we found that ethanol exposure induced epithelial to mesenchymal transition (EMT) through activating Wnt/β-catenin signaling pathway in HCC cells. We further demonstrated that β-catenin siRNA or salinomycin (an inhibitor of Wnt/β-catenin pathway) partially rescued ethanol-induced EMT. In conclusion, this study suggested that ethanol exposure promotes the metastasis and stemness of HCC cells by inducing EMT.

Is podoplanin expression associated with transforming growth factor-β signaling in odontogenic cysts and tumors?

BACKGROUND

Induction of podoplanin by transforming growth factor-β (TGF-β) has been shown in a number of lesions but not in odontogenic tumors (OTs). We evaluated the association between these markers in OTs for the first time and compared their expression among the different neoplasms.

METHODS

Immunohistochemistry using monoclonal antibody against podoplanin and TGF-β was performed on 76 odontogenic cysts and tumors. Spearman's correlation coefficient, Kruskal-Wallis, and Mann-Whitney U tests followed by adjustment with Bonferroni were used for statistical analysis (P < .05).

RESULTS

A significant difference in podoplanin expression was found among the lesions consisting of solid ameloblastomas, adenomatoid odontogenic tumors, ameloblastic fibromas, odontogenic myxomas (OMs), odontogenic keratocysts, and calcifying odontogenic cysts. Significant differences were observed only between OMs and each of the other neoplasms. Podoplanin immunostaining in the connective tissue was absent in most lesions. TGF-β was significantly different among the study sample but not between the lesions in paired comparisons. None of the studied OTs showed significant correlations between podoplanin-TGF-β, in either the epithelium or the stroma. These markers were also descriptively reported in calcifying epithelial odontogenic tumors.

CONCLUSIONS

The inductive effect of TGF-β on podoplanin seems to be limited, if any, in odontogenic lesions. Podoplanin appears to play a role in some aspects of OTs with epithelial or mixed origins. Despite the possible participation of podoplanin in tumorigenesis, it may not necessarily be involved in the aggressive behavior of OTs.

Differences in E-Cadherin and Syndecan-1 Expression in Different Types of Ameloblastomas

Ameloblastomas are a group of benign, locally aggressive, recurrent tumors characterized by their slow and infiltrative growth. E-Cadherin and syndecan-1 are cell adhesion molecules related to the behavior of various tumors, including ameloblastomas. Ninety-nine ameloblastoma samples were studied; the expression of E-cadherin and syndecan-1 were evaluated by immunohistochemistry. E-Cadherin and epithelial syndecan-1 were more highly expressed in intraluminal/luminal unicystic ameloblastoma than in mural unicystic ameloblastoma and solid/multicystic ameloblastoma, whereas the stromal expression of syndecan-1 was higher in mural unicystic ameloblastoma and solid/multicystic ameloblastoma. Synchronicity was observed between E-cadherin and epithelial syndecan-1; the expression was correlated with intensity in all cases. There was a strong association between expression and tumor size and recurrence. The evaluation of the expression of E-cadherin and syndecan-1 are important for determining the potential aggressiveness of ameloblastoma variants. Future studies are required to understand how the expression of these markers is related to tumor aggressiveness.

Prognostic Significance of EDIL3 Expression and Correlation with Mesenchymal Phenotype and Microvessel Density in Lung Adenocarcinoma

We examined the prognostic significance of Epidermal Growth Factor-like repeats and Discoidin I-Like Domains 3 (EDIL3) expression and its correlations with mesenchymal phenotype and microvessel density in non-small cell lung carcinoma (NSCLC). A total of 268 NSCLC specimens were evaluated retrospectively by immunohistochemical staining for EDIL3, EMT markers (e-cadherin, β-catenin, and vimentin), and CD31 to measure microvessel density. EDIL3, e-cadherin, β-catenin, and vimentin were expressed in 16%, 22.8%, 3.7%, and 10.1% of the specimens, respectively. The mRNA level of EDIL3 in tumor was correlated with the level of EDIL3 protein expression using immunohistochemistry. In lung adenocarcinoma patients, EDIL3 expression was significantly correlated with low e-cadherin expression, high vimentin expression, and increased microvessel density (P < 0.001, P = 0.001, and P = 0.023, respectively). In lung squamous cell carcinoma patients, EDIL3 expression was significantly correlated with low e-cadherin expression and high vimentin expression (P = 0.021 and P = 0.002, respectively). In lung adenocarcinoma patients, EDIL3 was an independent prognostic factor for overall survival in a multivariate analysis (hazard ratio: 2.552, P = 0.004). EDIL3 is significantly correlated with mesenchymal phenotype, angiogenesis, and tumor progression in lung adenocarcinoma.