Invadopodia proteins, cortactin and membrane type I matrix metalloproteinase (MT1-MMP) are expressed in ameloblastoma

Assessment of Protein Immunoexpression Associated with Tumor Proliferation and Invasion in Histological Subtypes of Unicystic and Conventional Ameloblastoma

The aim of this study was to verify whether the expression of proteins related to the formation of invadopodia, MT1-MMP, cortactin, Tks-4 and Tks-5 is associated with the degree of tumor invasiveness of different types of unicystic ameloblastomas. An immunohistochemical study was performed on 29 unicystic ameloblastoma (UA) samples, 9 conventional ameloblastoma (CAM) samples and 9 dental follicle (DF) samples. The potential for tumor invasiveness was assessed based on the immunoexpression of the following invadopodia-forming proteins: MT1-MMP, cortactin, Tks-4 and Tks5. Mural unicystic ameloblastoma (MUA) showed higher MT1-MMP, cortactin, Tks-4, and Tks-5 immunoexpression than luminal and intra-luminal types. Conventional ameloblastoma exhibited lower MT1-MMP, cortactin, and Tks-5 expression compared to MUA. MUA's cystic capsule neoplastic cells had significantly higher MT1-MMP, cortactin, Tks-4, and Tks-5 expression than lumen cells. Dental follicles showed minimal expression. Neoplastic cells in the cystic capsule of mural unicystic ameloblastomas showed higher invadopodia-related protein expression than lumen and luminal/intraluminal cells, suggesting that proximity to the bone region influences the aggressive behavior of mural unicystic ameloblastomas more compared to other subtypes.

Prognostic value of the expression and localization of cell proliferation and apoptosis markers in unicystic ameloblastomas

The aim of this study was to verify whether the expression of cell proliferation and apoptosis markers in different types of unicystic ameloblastoma (UA) is associated with the location of neoplastic cells. Immunohistochemical study with a sample of 32 cases of UA, 11 cases of conventional ameloblastoma (CAM) and ten dental follicles (DF) cases was performed. Cell proliferation was assessed using Ki-67 status, and apoptosis by caspase-3 expression. Mural UA (MUA) showed a higher immunostaining of Ki-67 (p < 0.05) and a lower immunostaining of Caspase-3 (p < 0.05) compared with luminal and intraluminal subtypes of UA and CAM. The neoplastic cells of the MUA's cystic capsule showed a higher expression of Ki-67 protein (p < 0.0001) and a lower expression of Caspase-3 (p < 0.0001) compared with the lumen. DF showed lower Ki-67 and Caspase-3 immunostaining (p < 0.05) than neoplasms. The higher immunoexpression of Ki-67 and the lower immunoexpression of Caspase-3 in MUA, in the parenchyma cells within the cystic capsule, suggest an association between the biological behaviour and location of neoplastic cells in a tumour.

Assessment of Invadopodium Formation and Gelatin Degradation in Vitro

Some cancer cells form highly regulated structures, termed invadopodia, which mediate local, enzymatic degradation of extracellular matrix and facilitate cancer cell invasion and migration during metastatic progression. Understanding invadopodium formation and function in cancer cells is therefore an important strategy to find novel clinical approaches to interfere with metastasis. Invadopodia are F-actin-rich protrusions that form on the advancing edge of cells, supported by complex molecular interactions at the cell membrane. Invadopodia formation, structure, and function can be studied in vitro, using commonly cultured cancer cell lines and standard microscopic techniques. Here, these approaches are described in detail.

Gene Expression and Immunochemistry Analysis of ADAMTS-1 and Versican in Ameloblastoma

Background

Ameloblastoma is a benign but locally invasive odontogenic epithelial tumor, associated with a high recurrence rate after treatment. The action of enzymes of the metalloproteinase family is important to the degraded extracellular matrix, contributing to invasion. Thus, this study aimed to investigate the gene and protein expression of ADAMTS-1 and versican in ameloblastoma.

Materials and Methods

Twenty cases of ameloblastoma (n = 20) and ten dental follicles (DF) (n = 10) were used as a source for immunochemistry and quantitative RT-PCR for determining the protein and mRNA expressions of the concerned genes, respectively. Moreover, western blot and indirect immunofluorescence analysis were performed in AME cells.

Results

ADAMTS-1 and versican were overexpressed in DF than ameloblastoma by RT-PCR. However, in the immunolocalization analysis, ADAMTS-1 was expressed in ameloblastoma more than in DF and versican immunostaining obtained a similar pattern between ameloblastoma and DF. Indirect immunofluorescence detected the ADAMTS-1 and versican expression in cell lines derived from ameloblastoma. Western blot from cell lysate and conditioned medium detected ADAMTS-1 bands representing full-length and different processed forms. Monensin treatment confined ADAMTS-1 in the cell cytoplasm. Versican fragments also were detected in different compartments, intracellular and conditioned medium, allowing the versican process by ADAMTS-1.

Conclusion

This study showed a distinct expression of ADAMTS-1 and versican in ameloblastoma and DF, with ADAMTS-1 protein higher expression observed in ameloblastoma and possibly cleaved versican. These findings suggested that ADAMTS-1 may participate in tumor invasion, especially for the degradation of substrates (versican) in the ECM.

Glandular odontogenic cysts: a collaborative investigation of 22 cases and proteins related to invasiveness

BACKGROUND

A glandular odontogenic cyst has an intriguing, aggressive behaviour whose mechanisms have not yet been clarified.

OBJECTIVE

To conduct a collaborative cross-sectional study on the clinical, demographic, microscopic, and immunohistochemical characteristics of glandular odontogenic cysts, emphasizing the histopathological characteristics and expression of proteins related to invasiveness.

METHODS

Twenty-two cases of glandular odontogenic cyst from three oral and maxillofacial pathology services in Brazil were selected from 1988 to 2018. Clinical and demographic data were collected. Histopathological features were evaluated in detail. Sixteen cases of glandular odontogenic cyst were also submitted to immunohistochemistry to detect MT1-MMP, TKS4, TKS5, and cortactin, the key regulators of invadopodia formation.

RESULTS

GOCs were primarily seen in men over 40 years of age, in the posterior mandible and the anterior maxilla as a unilocular, radiolucent lesion. All cases presented hobnail cells, clear cells, and variable thickness of the lining epithelium, three of the ten key histopathological parameters to be evaluated in glandular odontogenic cysts. Immunohistochemistry revealed a greater expression of the studied proteins in the glandular odontogenic cysts than in the controls (p <0.0001).

CONCLUSION

Overexpression of proteins that regulate cell invasiveness was identified, and the present study's findings suggest that invadopodia activity is a possible mechanism used by glandular odontogenic cysts to promote local invasion, which could partly explain its intriguing biological behaviour.

HIF-1α Is Associated with Resistance to Hypoxia-Induced Apoptosis in Ameloblastoma

Background

Ameloblastoma (AMB) is a benign odontogenic tumour, with an aggressive local behaviour and a high rate of recurrence. Previous studies have demonstrated that hypoxia-induced factor alpha 1 (HIF-1α) and activated caspase-3 contribute to tumour invasiveness and cytogenesis in ameloblastoma. Hypoxia increases HIF-1α levels, which triggers a number of signalling pathways. This paper aimed to present data in the study of hypoxia-activated signalling pathways that modulate proapoptotic and antiapoptotic events in AMB.

Methods

Twenty cases of AMB and ten cases of dental follicle (DF) were used to analyse the immunoexpression of HIF-1α, p53, BNIP3, Bcl-2, IAP-2, GLUT1, and Bax. To contribute to the study, an analysis of expression and genetic interaction was performed using the cell line AME-1.

Results

AMB and DF expressed the studied proteins. These proteins showed significantly greater immunoexpression in AMB compared with the DF (p < 0.05). HIF-1α showed an important association with GLUT1, and a positive correlation was observed among p53, Bcl-2, and IAP-2. Transcriptomic analysis showed the significant expression of the studied proteins, and the network generated showed a direct association of HIF-1αF with GLUT1 (SLC2A1), TP53, and LDHA. Interestingly, GLUT1 also exhibited direct interaction with TP53 and LDHA.

Conclusion

In AMB tumorigenesis, hypoxia is possibly related to antiapoptotic events, which suggests an important role for HIF-1α, GLUT1, Bcl-2, IAP-2, and possibly p53.

Immunolocalization of IP3R and V-ATPase in Ameloblastomas

The goal of this study was to investigate the immunolocalization of inositol 1,4,5-trisphosphate receptor (IP3R) and vacuolar ATPase (V-ATPase) in ameloblastomas with special attention to the invasive front. Thirty-seven cases of previously diagnosed formalin-fixed paraffin-embedded (FFPE) human ameloblastoma samples were selected for this study. The samples were grouped according to the predominant histologic pattern and comprised twelve plexiform, eighteen follicular, and seven unicystic ameloblastomas. Of the unicystic variants, six demonstrated purely luminal and intraluminal growth, and one displayed mural extension. One granular cell variant was included in the follicular ameloblastoma group. All specimens were evaluated for IP3R and V-ATPase expression by immunohistochemistry (IHC). IP3R was positive in columnar cells, similar to ameloblasts, and non-peripheral cells in all samples. In the area of tumor protrusion and front of invasion, membranous and cystoplasmic IP3R expression was observed. In contrast, areas adjacent to tumoral protrusion demonstrated only membranous staining patterns. V-ATPase was not expressed in peripheral columnar cells of the unicystic and granular cell variants of ameloblastoma; however, strong staining was present in these cells in plexiform ameloblastomas, follicular ameloblastomas, and areas of mural growth of unicystic ameloblastomas. In areas of tumor protrusion, reactivity for V-ATPase was observed with both membranous and cytoplasmic staining, while other areas showed only membranous V-ATPase. These findings suggest that concomitant immunolocalization of IP3R and V-ATPase, with both cytoplasmic and membranous expression in the peripheral columnar cells, may indicate the invasive potential of ameloblastomas. Furthermore, these results suggest the tumoral spread of ameloblastomas may be correlated with the autophagy process and channelopathy. The expression of these proteins could establish a baseline for future research and provide therapeutic targets for treatment of ameloblastomas.

Keratocystic odontogenic tumor overexpresses invadopodia-related proteins, suggesting invadopodia formation

OBJECTIVE

Keratocystic odontogenic tumor (KOT) is an odontogenic neoplasm that shows aggressive clinical behavior and local invasiveness. Invadopodia are actin-rich cellular protrusions exhibiting proteolytic pericellular activity, thereby inducing focal invasion in neoplastic cells and increasing neoplasms aggressiveness. Thus, this study aimed to evaluate immunoexpression of invadopodia-related proteins, cortactin, MT1-MMP, Tks4, and Tks5, in KOT.

STUDY DESIGN

Immunohistochemistry of 16 cases of KOT, eight cases of calcifying cystic odontogenic tumor (CCOT), and eight samples of the oral mucosa (OM) was carried out to assess the expression of the above described invadopodia-related proteins in the basal and suprabasal layer.

RESULTS

KOT samples showed higher and significant immunoexpression of cortactin, MT1-MMP, TKs4, and TKs5 compared with the CCOT and OM samples. Significant expression of all these proteins was observed in the basal layer compared with the suprabasal layer in KOT.

CONCLUSIONS

Overexpression of cortactin, MT1-MMP, TKs4, and TKs5 was observed in KOT compared with samples of CCOT and OM. These proteins were also overexpressed in the basal over the suprabasal layer of KOT samples. Taken together, these results suggest the participation of invadopodia-related proteins on the pathogenesis of this lesion.

Role of hypoxia-related proteins in invasion of ameloblastoma cells: crosstalk between NOTCH1, hypoxia-inducible factor 1α, a disintegrin and metalloproteinase 12, and heparin-binding epidermal growth factor

AIMS

Ameloblastoma AME is a benign tumour characterized by local invasiveness, high recurrence rates, and diverse histological patterns. The oxygen concentration is reduced in specific areas of the tumour microenvironment, which leads to intratumoral hypoxia. Crosstalk between NOTCH1, a disintegrin and metalloproteinase 12 (ADAM-12), hypoxia-inducible factor 1α (HIF-1α) and heparin-binding epidermal growth factor (HB-EGF) under hypoxic conditions has been implicated in invadopodia formation, tumour invasiveness, and metastasis development. The aim of this study was to analyse the expression of these proteins, in order to further elucidate the mechanisms underlying AME invasiveness.

METHODS AND RESULTS

Twenty cases of AME, eight calcifying cystic odontogenic tumours CCOTs and 10 samples of dental follicle were used to investigate the expression of these proteins by immunohistochemistry with the primary antibodies anti-NOTCH1, anti-ADAM-12, anti-HIF-1α, and anti-HB-EGF. Immunostaining results were expressed as the percentage of stained area in images acquired in an AxioScope microscope equipped with an AxioCamHRc camera and a × 40 objective. The results showed that immunoexpression of all proteins was higher in the AME samples than in the CCOT and dental follicle samples (P < 0.05).

CONCLUSIONS

AME showed an increased presence of proteins associated with tumour invasiveness, which indicates a possible role of these proteins in the biological behaviour of this tumour.

Invadopodia proteins, cortactin, N-WASP and WIP differentially promote local invasiveness in ameloblastoma

BACKGROUND

Cell migration and invasion through interstitial tissues are dependent upon several specialized characteristics of the migratory cell notably generation of proteolytic membranous protrusions or invadopodia. Ameloblastoma is a benign odontogenic epithelial neoplasm with a locally infiltrative behaviour. Cortactin and MMT1-MMP are two invadopodia proteins implicated in its local invasiveness. Other invadopodia regulators, namely N-WASP, WIP and Src kinase remain unclarified. This study addresses their roles in ameloblastoma.

MATERIALS AND METHOD

Eighty-seven paraffin-embedded ameloblastoma cases (20 unicystic, 47 solid/multicystic, 3 desmoplastic and 17 recurrent) were subjected to immunohistochemistry for expression of cortactin, N-WASP, WIP, Src kinase and F-actin, and findings correlated with clinicopathological parameters.

RESULTS

Invadopodia proteins (except Src kinase) and F-actin were widely detected in ameloblastoma (cortactin: n = 73/87, 83.9%; N-WASP: n = 59/87; 67.8%; WIP: n = 77/87; 88.5%; and F-actin: n = 87/87, 100%). Protein localization was mainly cytoplasmic and/or membranous, and occasionally nuclear for F-actin. Cortactin, which functions as an actin-scaffolding protein, demonstrated significantly higher expression levels within ameloblastoma tumoral epithelium than in stroma (P < 0.05). N-WASP, which coordinates actin polymerization and invadopodia-mediated extracellular matrix degradation, was overexpressed in the solid/multicystic subtype (P < 0.05). WIP, an upstream regulator of N-WASP, and F-actin were significantly upregulated along the tumour invasive front compared to tumour centres (P < 0.05). Except for males with cortactin overexpression, other clinical parameters (age, ethnicity and anatomical site) showed no significant correlations.

CONCLUSIONS

Present results suggest that local invasiveness of ameloblastoma is dependent upon the migratory potential of its tumour cells as defined by their distribution of cortactin, N-WASP and WIP in correlation with F-actin cytoskeletal dynamics.

Calcifying Cystic Odontogenic Tumour: immunohistochemical expression of matrix metalloproteinases, their inhibitors (TIMPs and RECK) and inducer (EMMPRIN)

BACKGROUND

Calcifying cyst odontogenic tumour (CCOT) is a rare benign cystic neoplasm of odontogenic origin. MMPs are responsible for extracellular matrix remodelling and, together their inhibitors and inducer, determinate the level of its turnover in pathological processes, leading to an auspicious microenvironment for tumour development. Thus, our goal was to evaluate matrix metalloproteinases (MMPs-2, -7, -9 and -14), their inhibitors (TIMPs-2, -3, -4 and RECK) and its inductor (EMMPRIN) expression in CCOT.

MATERIALS AND METHODS

We used 18 cases of CCOT submitted to immunolocalization of the target proteins and analysed in both neoplastic odontogenic epithelial and stromal compartments.

RESULTS

All molecules evaluated were expressed in both compartments in CCOT. In epithelial layer, immunostaining for MMPs, TIMPs, RECK and EMMPRIN was found in basal, suprabasal spindle and stellate cells surrounding ghost cells and ghost cells themselves, except for MMP-9 and TIMP-2 which were only expressed by ghost cells. In stromal compartment, extracellular matrix, mesenchymal (MC) and endothelial cells (EC) were positive for MMP-2, -7, TIMP-3 and -4, while MMP-9, TIMP-2 and RECK were positive only in MC and MMP-14 only in EC. Statistical significance difference was found between both compartments for MMP-9 (P < 0.001), RECK (P = 0.004) and EMMPRIN (P < 0.001), being more expressed in epithelium than in stroma. Positive correlation between both stromal EMMPRIN and RECK expression was found (R = 0.661, P = 0.003).

CONCLUSIONS

We concluded that these proteins/enzymes are differentially expressed in both epithelium and stroma of CCOT, suggesting an imbalance between MMPs and their inducer/inhibitors may contribute on the tumour behaviour.

Matrix metalloproteinases, tissue inhibitors of metalloproteinases, and growth factors regulate the aggressiveness and proliferative activity of keratocystic odontogenic tumors

OBJECTIVE

The objective of this preliminary study was to evaluate the expression of matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs) and growth factors in keratocystic odontogenic tumors (KOTs).

STUDY DESIGN

The expression of MMPs, TIMPs, growth factors, and the extracellular signal-regulated kinase (ERK) 1/2 signaling pathway were assessed by immunohistochemistry in 15 cases of KOT and 4 cases of calcifying cystic odontogenic tumor (CCOT).

RESULTS

KOT samples expressed significantly higher amounts of MMPs, TIMPs, growth factors, epidermal growth factor receptor (EGFR), and ERK compared with CCOT samples, with the exception of MMP-2 and TIMP-1.

CONCLUSIONS

MMP-9, TIMP-2, EGF and transforming growth factor α act together and likely regulate the proliferation and aggressiveness of KOT. ERK-1/2 serves as the transducer of signals generated by these proteins, which signal through the common receptor, EGFR. This process may be related to the increased proliferation and aggressiveness observed in KOT.