Immunoexpression of MMPs-1, -2, and -9 in ameloblastoma and odontogenic adenomatoid tumor

About a Possible Impact of Endodontic Infections by Fusobacterium nucleatum or Porphyromonas gingivalis on Oral Carcinogenesis: A Literature Overview

Periodontitis is linked to the onset and progression of oral squamous cell carcinoma (OSCC), an epidemiologically frequent and clinically aggressive malignancy. In this context, Fusobacterium (F.) nucleatum and Porphyromonas (P.) gingivalis, two bacteria that cause periodontitis, are found in OSCC tissues as well as in oral premalignant lesions, where they exert pro-tumorigenic activities. Since the two bacteria are present also in endodontic diseases, playing a role in their pathogenesis, here we analyze the literature searching for information on the impact that endodontic infection by P. gingivalis or F. nucleatum could have on cellular and molecular events involved in oral carcinogenesis. Results from the reviewed papers indicate that infection by P. gingivalis and/or F. nucleatum triggers the production of inflammatory cytokines and growth factors in dental pulp cells or periodontal cells, affecting the survival, proliferation, invasion, and differentiation of OSCC cells. In addition, the two bacteria and the cytokines they induce halt the differentiation and stimulate the proliferation and invasion of stem cells populating the dental pulp or the periodontium. Although most of the literature confutes the possibility that bacteria-induced endodontic inflammatory diseases could impact on oral carcinogenesis, the papers we have analyzed and discussed herein recommend further investigations on this topic.

Characterization of tumors of jaw: Additive value of contrast enhancement and dual-energy computed tomography

BACKGROUND

Currently, the differentiation of jaw tumors is mainly based on the lesion's morphology rather than the enhancement characteristics, which are important in the differentiation of neoplasms across the body. There is a paucity of literature on the enhancement characteristics of jaw tumors. This is mainly because, even though computed tomography (CT) is used to evaluate these lesions, they are often imaged without intravenous contrast. This study hypothesised that the enhancement characteristics of the solid component of jaw tumors can aid in the differentiation of these lesions in addition to their morphology by dual-energy CT, therefore improving the ability to differentiate between various pathologies.

AIM

To evaluate the role of contrast enhancement and dual-energy quantitative parameters in CT in the differentiation of jaw tumors.

METHODS

Fifty-seven patients with jaw tumors underwent contrast-enhanced dual-energy CT. Morphological analysis of the tumor, including the enhancing solid component, was done, followed by quantitative analysis of iodine concentration (IC), water concentration (WC), HU, and normalized IC. The study population was divided into four subgroups based on histopathological analysis-central giant cell granuloma (CGCG), ameloblastoma, odontogenic keratocyst (OKC), and other jaw tumors. A one-way ANOVA test for parametric variables and the Kruskal-Wallis test for non-parametric variables were used. If significant differences were found, a series of independent t-tests or Mann-Whitney U tests were used.

RESULTS

Ameloblastoma was the most common pathology (n = 20), followed by CGCG (n = 11) and OKC. CGCG showed a higher mean concentration of all quantitative parameters than ameloblastomas (P < 0.05). An IC threshold of 31.35 × 100 μg/cm3 had the maximum sensitivity (81.8%) and specificity (65%). Between ameloblastomas and OKC, the former showed a higher mean concentration of all quantitative parameters (P < 0.001), however when comparing unilocular ameloblastomas with OKCs, the latter showed significantly higher WC. Also, ameloblastoma had a higher IC and lower WC compared to "other jaw tumors" group.

CONCLUSION

Enhancement characteristics of solid components combined with dual-energy parameters offer a more precise way to differentiate between jaw tumors.

Developments on the Smart Hydrogel-Based Drug Delivery System for Oral Tumor Therapy

At present, an oral tumor is usually treated by surgery combined with preoperative or postoperative radiotherapies and chemotherapies. However, traditional chemotherapies frequently result in substantial toxic side effects, including bone marrow suppression, malfunction of the liver and kidneys, and neurotoxicity. As a new local drug delivery system, the smart drug delivery system based on hydrogel can control drug release in time and space, and effectively alleviate or avoid these problems. Environmentally responsive hydrogels for smart drug delivery could be triggered by temperature, photoelectricity, enzyme, and pH. An overview of the most recent research on smart hydrogels and their controlled-release drug delivery systems for the treatment of oral cancer is given in this review. It is anticipated that the local drug release method and environment-responsive benefits of smart hydrogels will offer a novel technique for the low-toxicity and highly effective treatment of oral malignancy.

Molecular biological findings of ameloblastoma

Ameloblastoma is benign odontogenic tumours that mainly occur in the jawbone. This tumour induces aggressive invasion into the surrounding bone and has a high recurrence rate after surgery. Therefore, mandibular resection is performed in many patients with this tumour, causing aesthetic and functional problems. It is necessary to develop a novel treatment strategy for ameloblastoma, but there are currently no innovative treatments. Although our understanding of the molecular biological mechanisms of ameloblastoma is still insufficient, there have been many recent reports of new molecular biological findings on ameloblastoma. Therefore, bioactive factors that have potential for novel therapeutic methods, such as molecular targeted therapy, have been discovered in ameloblastoma. In this review, we summarize the molecular biological findings of ameloblastoma reported over several decades, focusing on factors involved in invasion into surrounding tissues and disease-specific gene mutations. We also mention the effect of the interaction between tumour cells and stromal components in ameloblastoma on tumour development. Scientific field of dental Science: Oral surgery, Odontogenic tumor, Ameloblastoma.

Evaluation of the Connective Tissue Wall in Sporadic Cases of Keratocystic Odontogenic Tumor (KCOT) Using MMP-9 and Confocal Microscopy: A Retrospective Study

Background:

Keratocystic odontogenic tumor (KCOT) is an odontogenic lesion which manifests distinct biological behavior. Predominant studies in KCOT attribute this behavior to high epithelial proliferative capacity. Besides, a few studies facet loosely arranged collagen can contribute to the behavior of KCOT. Matrix metalloproteinases (MMP) are enzymes that degrade extracellular matrix components under both physiologic and pathologic conditions. The loosely arranged collagen in connective tissue wall of KCOT could be related to the degree of MMP-9 expression.

Aim:

To evaluate the arrangement of collagen fibers along with immunoexpression of MMP-9 and to relate to its neoplastic biologic behavior in sporadic cases of KCOT.

Materials and Methods:

KCOT ( n = 23) and dentigerous cyst (DC) ( n = 15) samples were processed for the following techniques: Masson’s trichrome stain for light microscopy, PMA-PSR stain for confocal microscopy, and MMP-9 for immunohistochemistry.

Results:

In Masson’s trichrome analysis, correlation of collagen fiber arrangement in the deeper regions with color intensity for KCOT was found to be statistically significant ( P = .033). In confocal microscopy, there was no difference between intensities in KCOT ( P = .990) and DC ( P = .233), respectively. The immunoexpression of MMP-9 in the connective tissue wall of DC (73.3%) was relatively higher than that of KCOT (60.8%). However, on comparison between KCOT and DC in the presence of inflammation, the immunoexpression of MMP-9 was higher in DC (100%) than KCOT (69.9%) and was statistically significant ( P = .028).

Conclusion:

It was concluded that the loose connective tissue wall in KCOT is because of the inherent nature of the lesion that could facilitate its biologic behavior. If inflammation is present, this could further aggravate the tumorigenic behavior.

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.

Immunohistochemical expression of osteonectin, matrix metalloproteinases-9 and Ki-67 in ameloblastoma

Background:

Ameloblastoma (AM) is a benign odontogenic neoplasm characterized by local invasiveness and recurrence. We have evaluated the immunohistochemical expressions of osteonectin (ON), matrix metalloproteinase-9 (MMP-9) and Ki-67 in AM to understand the biologic behavior of this neoplasm.

Aim:

The aim of this study is to evaluate the expression of ON, MMP-9 and Ki-67 in AM.

Materials and Methods:

The study sample included archival tissues embedded in paraffin blocks histopathologically diagnosed as AM (20 cases). Three serial sections of each tissue specimen were stained separately with ON, MMP-9 and Ki-67 (immunohistochemistry stain) and evaluated. The data were analyzed using Spearman rank correlation test.

Results:

All AM cases 20/20 (100%) exhibited positive immunostaining for ON, MMP-9 and Ki-67.

Conclusion:

Increased expression of ON, MMP-9 and Ki-67 in AM indicates that these molecules might play a role in the regulation and aggressive nature of this neoplasm.

Focal Adhesion Kinase Expression in Ameloblastoma: A Preliminary Observational Study

INTRODUCTION

Focal Adhesion Kinase (FAK) is a membrane-associated molecule, which plays a major role in tumourigenesis by promoting cell survival, proliferation, migration, and invasion. Hence, FAK is a well known molecule that has been targeted therapeutically for the treatment of various malignancies. Ameloblastoma (AB) is a locally invasive, destructive and recurrent benign odontogenic lesion. Based on these properties, we have hypothesized that odontogenic epithelium of AB could show increased expression of FAK.

AIM

To study the expression of FAK in odontogenic epithelium of AB using immunohistochemistry.

MATERIALS AND METHODS

Thirty four paraffin embedded AB and 17 Dental Follicle (DF) tissues were retrieved from archives. Immunohistochemical staining was performed using FAK antibody on 5 μm thick formalin fixed paraffin embedded sections. The expression of FAK was studied in ameloblast like cells and stellate reticulum-like cells and was graded as negative, weak and strong. The data was analysed using chi-square test and Fisher's-exact test.

RESULTS

In AB, both ameloblast like and stellate reticulum like cells showed positive expression of FAK in the cytoplasm in all the cases (34). The epithelial islands from all the DFs (17) were negative for FAK expression. The difference in the expression of FAK in ameloblast like and stellate reticulum like cells was statistically significant (p<0.0001). Statistically significant difference was observed in the expression of FAK in stellate reticulum like cells of AB and odontogenic epithelial islands of DF (p = 0.0017). All the AB cases showed strong expression of FAK in ameloblast like cells and negative expression was seen in all the cases of DF.

CONCLUSION

FAK was strongly expressed in AB as compared to epithelial islands of DF. FAK could be responsible for the neoplastic nature of AB and possibly play a role in tumour invasiveness.

Ameloblastoma: current etiopathological concepts and management

Ameloblastoma is a benign odontogenic tumor of epithelial origin. It is locally aggressive with unlimited growth capacity and has a high potential for malignant transformation as well as metastasis. Ameloblastoma has no established preventive measures although majority of patients are between ages 30 and 60 years. Molecular and genetic factors that promote oncogenic transformation of odontogenic epithelium to ameloblastoma are strongly linked to dysregulation of multiple genes associated with mitogen-activated protein kinase, sonic hedgehog, and WNT/β-catenin signaling pathways. Treatment of ameloblastoma is focused on surgical resection with a wide margin of normal tissue because of its high propensity for locoregional invasion; but this is often associated with significant patient morbidity. The relatively high recurrence rate of ameloblastoma is influenced by the type of molecular etiological factors, the management approach, and how early the patient presents for treatment. It is expected that further elucidation of molecular factors that orchestrate pathogenesis and recurrence of ameloblastoma will lead to new diagnostic markers and targeted drug therapies for ameloblastoma.

Kallikrein 4 and matrix metalloproteinase-20 immunoexpression in malignant, benign and infiltrative odontogenic tumors

CONTEXT

Matrix metalloproteinase-20 (MMP20) (enamelysin) and kallikrein 4 (KLK4) are enzymes secreted by ameloblasts that play an important role in enamel matrix degradation during amelogenesis. However, studies have shown that neoplastic cells can produce such enzymes, which may affect the tumor infiltrative and metastatic behaviors.

AIMS

The aim of this study is to assess the biological role of MMP20 and KLK4 in odontogenic tumors.

MATERIALS AND METHODS

The enzymes were analyzed immunohistochemically in ameloblastoma, adenomatoid odontogenic tumor (AOT), calcifying epithelial odontogenic tumor, keratocystic odontogenic tumor with or without recurrence and odontogenic carcinoma.

STATISTICAL ANALYSIS USED

Clinicopathological parameters were statistically correlated with protein expression using the Fisher's exact test. Kruskal-Wallis and Wilcoxon-independent methods were used to evaluate the differences in median values.

RESULTS

Positive Immunoexpression was detected in all benign lesions, with a prevalence of 75-100% immunolabeled cells. Patients were predominantly young, Caucasian, female, with slow-growing tumors located in the mandible causing asymptomatic swelling. No KLK4 expression was seen in carcinomas, and the amount of MMP20-positive cells varied between 20% and 80%. Rapid evolution, recurrence and age >60 years characterized the malignant nature of these lesions.

CONCLUSIONS

Data showed that KLK4 and MMP20 enzymes may not be crucial to tumoral infiltrative capacity, especially in malignant tumors, considering the diversity and peculiarity of these lesions. The significant immunoexpression in benign lesions, remarkably in AOT, is likely associated with differentiated tumor cells that can produce and degrade enamel matrix-like substances. This would be expected since the histogenesis of odontogenic tumors commonly comes from epithelium that recently performed a secretory activity in tooth formation.

Immunohistochemistry of Five Molecular Markers for Typing and Management of Ameloblastomas: A Retrospective Analysis of 40 Cases

PURPOSE

The aims of this study are to elucidate if molecular markers can be used to differentiate between the two main types of ameloblastoma (unicystic and solid/multicystic), and to determine whether a biologically 'less-aggressive' subtype exists.

METHODS

A retrospective analysis of 33 solid/multicystic ameloblastomas and six unicystic ameloblastomas was completed using immunohistochemistry for five molecular markers: P16, P53, MMP-9, Survivin, and Ki-67. Tumors were graded as either negative or positive (mild, moderate, strong), and the results were related to both ameloblastoma subtypes and outcomes following treatment.

RESULTS

Unicystic ameloblastomas were more likely to test strongly positive for P53 than solid/multicystic ameloblastomas (p < 0.05), whereas the latter were more likely to be negative for Survivin (p < 0.05). Solid/multicystic and Type 3 unicystic ameloblastomas that were positive for P16, but also negative for MMP-9 and Survivin, were less likely to recur than all other tumors (p < 0.05). The proliferation index of an ameloblastic carcinoma (11 %) was shown to be higher than benign ameloblastomas (4.5 %).

CONCLUSIONS

Immunohistochemistry can be valuable in lesions where histological sub-typing of an ameloblastoma is unclear. A biologically 'less-aggressive' subtype may exist, and hence further research into this area is required.

Quantitative evaluation of microvessel density using CD34 in clinical variants of ameloblastoma: An immunohistochemical study

Background:

Odontogenic epithelium plays an important role in the histogenesis of odontogenic tumors of the jaws. Ameloblastomas, which arise from odontogenic epithelium, are considered benign with little tendency to metastasize. Tumors require an adequate supply of oxygen and a way to remove their waste products. This can be achieved by angiogenesis. In situ quantification of the microvessel density (MVD) is a usual method for assessing angiogenesis. Moreover, angiogenesis may differ in subtypes of ameloblastomas and could play a role in determining the pattern of tumor growth.

Aim:

The aim of the present study was to demonstrate the expression of cluster of differentiation (CD34) in variants of ameloblastomas and to correlate and compare their expression to the aggressive behavior.

Materials and Methods:

A retrospective cross-sectional study which included forty paraffin blocks was conducted after obtaining ethical committee clearance. Ten cases of pyogenic granuloma were used as a positive control and thirty cases were of solid multicystic ameloblastoma (SMA), unicystic ameloblastoma (UA) and desmoplastic ameloblastomas. Angiogenesis was assessed using CD34 antigen and was immunohistochemically localized. Statistical analysis was carried out for comparative analysis with the help of ANOVA test, Kolmogorov–Smirnov test and least significance difference test.

Results:

A significant correlation was obtained between the MVD of all the three variants, i.e., SMA, UA and desmoplastic ameloblastomas which was statistically significant (P < 0.05).

Conclusion:

Increased MVD in the three variants, i.e., SMA, UA and desmoplastic ameloblastoma seen in the present study could suggest that the angiogenesis has an important role in tumor progression and aggressiveness of ameloblastomas.

Molecular Signaling in Benign Odontogenic Neoplasia Pathogenesis

Several molecular pathways have been shown to play critical roles in the pathogenesis of odontogenic tumors. These neoplasms arise from the epithelial or mesenchymal cells of the dental apparatus in the jaw or oral mucosa. Next generation genomic sequencing has identified gene mutations or single nucleotide polymorphisms associated with many of these tumors. In this review, we focus on two of the most common odontogenic tumor subtypes: ameloblastoma and keratocystic odontogenic tumors. We highlight gene expression and protein immunohistological findings and known genetic alterations in the hedgehog, BRAF/Ras/MAPK, epidermal growth factor receptor, Wnt and Akt signaling pathways relevant to these tumors. These various pathways are explored to potentially target odontogenic tumors cells and prevent growth and recurrence of disease. Through an understanding of these signaling pathways and their crosstalk, molecular diagnostics may emerge as well as the ability to exploit identified molecular differences to develop novel molecular therapeutics for the treatment of odontogenic tumors.

Surface vacuolar ATPase in ameloblastoma contributes to tumor invasion of the jaw bone

Ameloblastoma is the most common benign odontogenic tumor in Japan. It is believed that it expands in the jaw bone through peritumoral activation of osteoclasts by receptor activator of nuclear factor kappa-B ligand (RANKL) released from the ameloblastoma, as in bone metastases of cancer cells. However, the clinical features of ameloblastoma, including its growth rate and patterns of invasion, are quite different from those of bone metastasis of cancer cells, suggesting that different underlying mechanisms are involved. Therefore, in the present study, we examined the possible mechanisms underlying the invasive expansion of ameloblastoma in the jaw bone. Expression levels of RANKL assessed by western blotting were markedly lower in ameloblastoma (AM-1) cells than in highly metastatic oral squamous cell carcinoma (HSC-3) cells. Experiments coculturing mouse macrophages (RAW264.7) with AM-1 demonstrated low osteoclastogenic activity, as assessed by tartrate-resistant acid phosphatase (TRAP)-positive multinuclear cell formation, probably because of low release of RANKL, whereas cocultures of RAW264.7 with HSC-3 cells exhibited very high osteoclastogenic activity. Thus, RANKL release from AM-1 appeared to be too low to generate osteoclasts. However, AM-1 cultured directly on calcium phosphate-coated plates formed resorption pits, and this was inhibited by application of bafilomycin A1. Furthermore, vacuolar-type H+-ATPase (V-ATPase) and H+/Cl- exchange transporter 7 (CLC-7) were detected on the surface of AM-1 cells by plasma membrane biotinylation and immunofluorescence analysis. Immunohistochemical analysis of clinical samples of ameloblastoma also showed plasma membrane-localized V-ATPase and CLC-7 in the epithelium of plexiform, follicular and basal cell types. The demineralization activity of AM-1 was only 1.7% of osteoclasts demineralization activity, and the growth rate was 20% of human normal skin keratinocytes and HSC-3 cells. These results suggest that the slow expansion of several typical types of ameloblastomas in jaw bone is attributable to its slow growth and low demineralization ability.

A case report and short review on changing trends in the site of occurrence of adenomatoid odontogenic tumor: Unravelling the past 15 years

Adenomatoid odontogenic tumor (AOT) is an uncommon benign odontogenic lesion, with debatable histogenesis and variable histopathology. A systematic and diverse insight into the evolution, clinical presentation, histology, and immunohistochemical findings of this lesion is reviewed and presented. We reviewed the data published from 2000 to 2014 of approximately 255 cases that revealed a significant change in the incidence of predominant site involved, in contrast to the findings published by Reichart. We have also included the chronological order of events leading to the coining of the term AOT, which shows the curiosity that has been dedicated to understanding the lesion. Immunohistochemistry is considered to be a hallmark in pathology for learning the molecular pathogenesis and giving a correct final diagnosis. Several markers have been used to investigate and understand this lesion, and a compilation of the findings has been tabulated.

Immunohistochemical expression of WNT5A and MMPs in odontogenic epithelial tumors and cysts

OBJECTIVE

The aim of this study was compare the expression of WNT5A and MMP2, 7 and 20, in frequent benign odontogenic tumors and odontogenic cysts, since these lesions have a different biological behavior.

MATERIALS AND METHODS

Eighty-one paraffin-embedded specimens of odontogenic tumors, including ameloblastoma and keratocystic odontogenic tumor, and thirty-two odontogenic cysts were used for immunohistochemical analysis.

RESULTS

The expression of WNT5A in odontogenic tumors and inflammatory cyst was higher than in developmental odontogenic cyst. There was no statistical difference (p<0.05) in the expression of WNT5A when comparing the analyzed tumors. The expression of MMP7 was lower in RC with a statistical difference when compared with all tumors and cysts. Statistical differences also occurred when comparing glandular odontogenic cyst (GOC) to keratocyst odontogenic tumor (KOT) and calcifying cystic odontogenic tumor (CCOT). MMP20 expression was higher in ameloblastoma when compared to adenomatoid odontogenic tumor (AOT), DC and GOC. The expression of MMP20 was lower in CCOT when compared to all tumors and cysts.

CONCLUSIONS

The expression of WNT5A in a group of odontogenic lesions suggests the participation of a non-canonical WNT signaling pathway in the progression and maintenance of these lesions. These molecules are possibly involved in the biological differences between odontogenic tumors and cysts. Considering previous studies, WNT5A may help promote the calcification seen in AOT, CCOT and CEOT by activating MMP7.

Molecular concepts in the pathogenesis of ameloblastoma: implications for therapeutics

Ameloblastoma is a benign odontogenic neoplasm that may exhibit aggressive biological behavior as evidenced by its rapid growth and significance recurrence rates following initial surgical resection. Currently, the only therapy for ameloblastoma is surgical, and adjunctive treatment modalities are needed to mitigate tumor growth and to reduce the need for extensive and disfiguring surgeries. Many studies have identified markers expressed by ameloblastoma and these lend insight to our understanding of tumor progression. This review provides a summary of the specific molecular pathways implicated in tumor pathogenesis, including those involved in bone remodeling, apoptosis, cell signaling, and tumor suppression. Based on these data, we identify several prognostic or therapeutic markers that have been used successfully in the treatment of other neoplastic processes that may also have diagnostic and prognostic utility for ameloblastoma. Thus, it is important to determine which markers hold the greatest promise for clinical management of this benign neoplasm in order to improve treatment options, particularly in patients with aggressive forms of ameloblastoma.

Immunohistochemical Analysis of Matrix Metalloproteinases-1,-9 and Tenascin in Odontogenic Lesions

Ameloblastoma (ABL) and keratocystic odontogenic tumor (KOT) are benign odontogenic tumors with local aggressive behaviors. The purpose of our study was to compare MMP-1, MMP-9 and tenascin staining patterns between “aggressive” ameloblastoma / keratocystic odontogenic tumors and “non-aggressive” radicular cysts (RC)/ dentigerous cysts (DC). Ameloblastoma, keratocystic odontogenic tumor, radicular cyst (RC) and dentigerous cyst (DC) specimens were chosen from the archives of Gazi University Faculty of Dentistry, Department of Oral Pathology, and immunohistochemically stained with MMP-1, -9 and tenascin antibodies. The immunohistochemical expressions were noted and statistically analyzed. The ABLs and KOTs showed significantly higher MMP-1 and -9 positivity than the RCs and DCs (p<0.05). The ABL and KOT basement membranes showed more continuous tenascin expression. Tenascin intensity was significantly higher in the ABLs and KOTs compared to the RCs and DCs (p<0.05). The results suggest that higher expression of MMP-1 and -9 may play an essential role in the growth and progression of these tumors. Continuous tenascin positivity may reflect strong connective tissue reaction against the invasive epithelial parts of ABLs and KOTs.

Endodontic therapy of a mandibular canine tooth with irreversible pulpitis secondary to dentigerous cyst

Dentigerous cysts are uncommon, yet are being reported with increasing frequency in the veterinary literature. Dentigerous cysts are a type of benign odontogenic cyst associated with impacted teeth, most commonly the mandibular first premolar tooth. Significant bone destruction can occur secondary to the expansion of a dentigerous cyst. The expanding cyst can lead to pathology of neighboring teeth, which can include external root resorption or pulpitis. Intraoral dental radiographs are imperative to properly assess the presence and extent of a dentigerous cyst, as well as the status of the neighboring teeth. This case report describes treatment for dentigerous cyst including cyst lining curettage, mandibular bone regeneration, and endodontic therapy for a canine tooth with irreversible pulpitis.

Immunoexpression of metalloproteinases 2 and 14 and TIMP-2 inhibitor in main types of primary gastric carcinomas and lymph node metastasis

Metalloproteinase-2 (MMP-2) and -14 (MMP-14) and the tissue inhibitor of metalloproteinases type 2 (TIMP-2) participate in epithelial-mesenchymal transition and tumor progression in many cancers. However, the correlation between these enzymes in gastric cancer and the metastatic potential to their respective lymph node needs to be determined. Here, we evaluated the expression of these enzymes in gastric carcinoma and lymph node metastases and their possible involvement in tumor progression. Histological samples from 83 patients with gastric cancer and their respective lymph nodes were used. MMP-2, MMP-14 and TIMP-2 immunoexpression was scored. TIMP-2 expression in tumor-associated macrophages occurred more frequently than in normal mucosa (P = 0.0128). Female tumor samples presented higher MMP-2 expression (P = 0.0248), while TIMP-2 occurred mainly in patients over 50 years old (P = 0.0034). MMP-2 was higher expressed in primary tumor macrophages than in neoplastic cells (P = 0.0118), and was also seen in macrophages from metastatic-affected lymph nodes of intestinal and diffuse histotypes (P = 0.0006). MMP-2, MMP-14 and TIMP-2 expression in mononuclear cells might be correlated with progression of gastric cancer. MMP-14 production by macrophages appears to be more involved in diffuse gastric cancer progression.

Matrix metalloproteinase-9 (mmp-9) expression in different subtypes of ameloblastoma

BACKGROUND

Ameloblastoma is a common benign odontogenic tumor of the jaw with a local invasive and highly destructive behavior and can develop in any age, with peak prevalence in 3rd-4th decade. Ameloblastoma can be divided into six histological types: follicular, plexiform, acanthomatous, desmoplastic, granular, and basal cell. Matrix metalloproteinase-9 (MMP-9) (92-kD gelatinase/type IV collagenases = gelatinase B) is involved in bone resorption by degradation of extracellular matrix and osteoclasts recruitment. Recent studies have found that MMP-9 is expressed by ameloblastoma and has a role in ameloblastoma local invasiveness.

OBJECTIVE

To analyze MMP-9 expression between different histological types of ameloblastoma.

MATERIAL AND METHOD

Forty samples of ameloblastoma were collected through consecutive sampling and the MMP-9 expression was detected using immunohistochemistry.

RESULT

All samples showed positive MMP-9 expression with moderate to strong intensity. 82.4 % plexiform type and 83.3 % mixed type have strong immunoexpression, significantly different with follicular type with only 36.4 % (P < 0.05).

CONCLUSION

Ameloblastoma plexiform and mixed type have higher MMP-9 expression than ameloblastoma follicular type. Different MMP-9 expression may contribute in different ameloblastoma biological behavior.

Immunohistological features in adenomatoid odontogenic tumor: review of the literature and first expression and mutational analysis of β-catenin in this unusual lesion of the jaws

PURPOSE

To investigate for the first time the immunohistochemical and mutational status of β-catenin in a mandibular case of adenomatoid odontogenic tumor (AOT) and to review the immunohistochemical expression data of various markers (cytokeratins, metalloproteinases, etc) in such a lesion.

MATERIALS AND METHODS

A case of follicular-type AOT in a young male patient was analyzed in regard to the immunohistochemical expression of β-catenin and mutations of the β-catenin gene (CTNNB1). Its expression is altered in some odontogenic tumors.

RESULTS

We found a strong cytoplasmic expression of β-catenin, but no molecular anomaly within the exon 3 of CTNNB1. β-catenin is considered to play a role in cell differentiation processes.

CONCLUSION

Our results were consistent with previous findings in ameloblastoma and malignant odontogenic tumors. However, β-catenin alterations had not been explored in AOT so far. Further studies are necessary to understand the specific regulation of β-catenin in the AOT pathogenesis.

Comparative immunohistochemical study of ameloblastoma and ameloblastic carcinoma

OBJECTIVE

Ameloblastic carcinoma combines the histologic features of ameloblastoma with cytologic atypia, regardless of whether it has metastasized. Because of its rarity, there are few immunoprofile studies of ameloblastic carcinoma and few comparative studies of ameloblastic carcinoma and ameloblastoma. In this study, we compared the expression levels of cytokeratins (CKs), matrix metalloproteinases (MMPs), and Ki-67 between ameloblastoma and ameloblastic carcinoma, and assessed the usefulness of these markers for differentiating the tumors.

STUDY DESIGN

We assessed CK7, CK14, CK18, CK19, MMP-2, MMP-9, and Ki-67 expression by immunohistochemistry in 10 cases of ameloblastoma and 7 cases of ameloblastic carcinoma and then compared expression patterns between the 2 groups.

RESULTS

Immunostaining for CK14 and CK19 was diffuse and strongly positive in both tumor types, but staining for CK7 was focally positive in only 1 case of ameloblastoma and absent in all cases of ameloblastic carcinoma. However, there was a significant difference in CK18 expression between the 2 tumors (P = .000). Whereas 80% of ameloblastomas showed negative reactivity for CK18, most cases of ameloblastic carcinomas showed a moderate to strong intensity of immunostaining for CK18. Regarding the expression of MMPs, there were significant differences in parenchymal MMP-2 and stromal MMP-9 expression between the 2 tumors. Compared to ameloblastoma, ameloblastic carcinoma showed significantly strong expression of MMP-2 in parenchymal cells (P = .001) and MMP-9 in stromal cells (P = .013). However, there were no differences in MMP-2 expression of stromal cells and MMP-9 expression of parenchymal cells between ameloblastoma and ameloblastic carcinoma. The mean Ki-67 labeling index (LI) of ameloblastic carcinomas was 17.21%, which was significantly higher than that of ameloblastomas (3.57%; P = .002).

CONCLUSIONS

The significant expression of CK18, parenchymal MMP-2, stromal MMP-9, and Ki-67 could provide useful markers for differentiating ameloblastic carcinoma from ameloblastoma.

Induction of secretory leukocyte protease inhibitor (SLPI) in estradiol valerate (EV) induced polycystic ovary

The excessive administration of estradiol valerate induces polycystic ovary syndrome by formation of follicular cysts. Secretory leukocyte protease inhibitor (SLPI) promotes wound healing by decreasing the excessive inflammatory response, stimulating keratinocyte proliferation and increasing collagen deposition through the inhibition of protease activity. In this study, SLPI expression was high in the ovarian stroma, corpus luteum, unilaminar primary follicle, multilaminar primary follicle and granulose layer of the antral follicle in polycystic ovary (PCO) compared to the normal ovary. SLPI was expressed strongly in the theca around the cyst in PCO compared to the mature follicle in the normal ovary. The levels of SLPI mRNA and protein expression were higher in PCO than in the normal ovary, and the level of MMP-2 expression was lower in PCO. These results showed that the formation of a cyst was initiated from a multilaminar primary follicle and SLPI expression was increased depending on the morphological changes in the follicle and ovarian stroma. Therefore, an increase in SLPI may be related to the suppression of tissue disruption, and act as a protease inhibitor in PCO, suggesting that SLPI increases independently of the estrogen concentration in pathological tissues.