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

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.

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.

A comparative immunohistochemical analysis of cortactin in orthokeratinized odontogenic cyst (OOC), sporadic odontogenic keratocyst (OKC), and syndromic OKC

OBJECTIVES

To evaluate and compare the immunohistochemical expression of cortactin in the epithelial lining of orthokeratinized odontogenic cyst (OOC), sporadic odontogenic keratocyst (OKC), and syndromic OKC.

METHODS

Formalin-fixed paraffin-embedded tissue blocks of histopathologically diagnosed cases of OOC, OKC, syndromic OKC, normal buccal mucosa (NBM), and oral squamous cell carcinoma (OSCC) were examined for immunohistochemical expression of cortactin. Clear brown cytoplasmic and membranous staining was considered positive.

RESULTS

A statistically significant difference was observed between OOC and syndromic OKC (p<0.001), as well as between sporadic OKC and syndromic OKC (p<0.001). Although not statistically significant, the expression of cortactin was slightly higher in the basal layer of NBM (mean=0.47), OOC (mean=0.27), sporadic OKC (mean=0.47) syndromic OKC (mean=1.53), and OSCC (mean=0.67) than in the parabasal layers of NBM (mean=0.27), OOC (mean=0.20), sporadic OKC (mean=0.47), syndromic OKC (mean=1.27), and OSCC (mean=0.60).

CONCLUSION

The expression of cortactin in the basal layer may suggest the formation of invadopodia in the basal layer where the invasion mechanism occurs. This finding is further supported by the higher localization of cortactin in areas of epithelial budding and daughter cysts in syndromic OKC, thereby reaffirming its possible association with recurrence.

Key proteins of invadopodia are overexpressed in oral squamous cell carcinoma suggesting an important role of MT1-MMP in the tumoral progression

BACKGROUND

Oral squamous cell carcinoma (OSCC) is the most relevant malignant neoplasm among all head and neck tumours due to its high prevalence and unfavourable prognosis. Tumour invasion and metastasis that affect prognosis are result of a set of complex events that cells with invasive potential use to spread to other regions. These cells use several mechanisms to invade tissues, including a type of finger-like membrane protrusion called invadopodia. This study aims to investigate the immunoexpression of invaopodia related-proteins TKs5, cortactin, TKs4 and MT1-MMP in OSCC and correlate it to clinicopathological data.

METHODS

An immunohistochemical evaluation of fifty cases of OSCCs and 20 cases of oral mucosa (OM) were assessed. The expression of invadopodia proteins were analysed in comparison to normal tissue (OM) and correlated to different clinical-stage and histological grade of OSCC.

RESULTS

TKs5, cortactin, TKs4 and MT1-MMP were significantly overexpressed in OSCC when compared to OM (p < 0.0001). Among tumour stages, TKs5 showed a statistical difference in immunolabelling between stage I and III (p = 0.026). Cortactin immunolabelling was statistically higher in grade I than in grade II and III. No differences were seen on TKs4 expression based on tumour staging or grading. MT1-MMP was higher expressed and showed statistical difference between stages I and III and grades I compared to II and III.

CONCLUSIONS

The invadopodia related-proteins were found to be overexpressed in OSCC when compared to OM, suggesting invadopodia formation and activity. Besides overexpressed in OSCC, cortactin, TKs4 and TKs5 showed no or ambiguous differences in protein expression when compared among clinical-stages or histological grades groups. Conversely, the expression of MT1-MMP increased in advanced stages and less differentiated tumours, suggesting MT1-MMP expression as a promising prognostic marker in OSCC.

Advances in Understanding TKS4 and TKS5: Molecular Scaffolds Regulating Cellular Processes from Podosome and Invadopodium Formation to Differentiation and Tissue Homeostasis

Scaffold proteins are typically thought of as multi-domain "bridging molecules." They serve as crucial regulators of key signaling events by simultaneously binding multiple participants involved in specific signaling pathways. In the case of epidermal growth factor (EGF)-epidermal growth factor receptor (EGFR) binding, the activated EGFR contacts cytosolic SRC tyrosine-kinase, which then becomes activated. This process leads to the phosphorylation of SRC-substrates, including the tyrosine kinase substrates (TKS) scaffold proteins. The TKS proteins serve as a platform for the recruitment of key players in EGFR signal transduction, promoting cell spreading and migration. The TKS4 and the TKS5 scaffold proteins are tyrosine kinase substrates with four or five SH3 domains, respectively. Their structural features allow them to recruit and bind a variety of signaling proteins and to anchor them to the cytoplasmic surface of the cell membrane. Until recently, TKS4 and TKS5 had been recognized for their involvement in cellular motility, reactive oxygen species-dependent processes, and embryonic development, among others. However, a number of novel functions have been discovered for these molecules in recent years. In this review, we attempt to cover the diverse nature of the TKS molecules by discussing their structure, regulation by SRC kinase, relevant signaling pathways, and interaction partners, as well as their involvement in cellular processes, including migration, invasion, differentiation, and adipose tissue and bone homeostasis. We also describe related pathologies and the established mouse models.

HIF-1α is Overexpressed in Odontogenic Keratocyst Suggesting Activation of HIF-1α and NOTCH1 Signaling Pathways

Background: The odontogenic keratocyst (OKC) is an odontogenic cyst that shows aggressive and intriguing biological behavior. It is suggested that a hypoxic environment occurs in OKC, which led us to investigate the immunoexpression and location of hypoxia-inducible factor 1-alpha (HIF-1α) and other hypoxia-related proteins. Methods: Twenty cases of OKC were evaluated for the expression of Notch homolog 1 (NOTCH1), HIF-1α, disintegrin and metalloproteinase domain-containing protein 12 (ADAM-12), and heparin-binding epidermal growth factor-like growth factor (HBEGF) by immunohistochemistry and compared to eight control cases of calcifying odontogenic cystic (COC), orthokeratinized odontogenic cyst (OOC), and normal oral mucosa (OM) in basal and parabasal layers. Results: In OKC, all the proteins tested were expressed significantly higher in both basal (except for NOTCH1 and HBEGF in OOC) and suprabasal epithelial layers compared to controls. Looking at the epithelial layers within OKC, we observed an increased NOTCH1 and HIF-1α expression in parabasal layers. Conclusions: These results suggest that hypoxia occurs more intensively in OKC compared to COC, OM, and OOC. Hypoxia appeared to be stronger in parabasal layers as observed by higher HIF-1α expression in upper cells. Overexpression of NOTCH1, ADAM-12, and HBEGF in OKC was observed, which suggests that microenvironmental hypoxia could potentially regulate the expression of hypoxia-related proteins, and consequently, its clinical and biological behavior.

Role of HIF-1α and CASPASE-3 in cystogenesis of odontogenic cysts and tumors

OBJECTIVES

Odontogenic cysts and tumors are the most relevant lesions that affect the gnathic bones. These lesions have in common the formation of cystic areas and this common feature may suggest involvement of similar mechanisms. The hypoxia inducible factor 1 alpha (HIF-1α), a responsive protein to hypoxia and caspase-3, an irreversible apoptosis marker, may contribute to cyst formation. Thus, this study aimed to investigate the immunoexpression of these proteins in odontogenic cysts and tumors.

MATERIAL AND METHODS

Twenty cases of ameloblastoma, keratocystic odontogenic tumor (KOT) (n = 20), radicular cyst (RC) (n = 18), dentigerous cyst (DC) (n = 11), calcifying cystic odontogenic tumor (n = 8), and dental follicle (DF) (n = 10) were used to investigate HIF-1α and caspase-3 expression in sequential serial cuts by immunohistochemistry.

RESULTS

HIF-1α was overexpressed in RC, DC, and ameloblastoma when compared with DF. The basal and sometimes the lower suprabasal layer showed no or very low expression in DC, KOT, and ameloblastoma, the last also showing strong expression in solid epithelial areas and initial cystic formation regions. Caspase-3 was found to be overexpressed in all lesions, with the highest expression in odontogenic cysts compared to tumors. HIF-1α and caspase-3 were localized in similar areas of the same lesions, especially in the epithelium surrounding cystic formations.

CONCLUSIONS

This study showed distinct immunoexpression of HIF-1α and caspase-3 in odontogenic cyst and tumors, with higher expression observed in odontogenic cysts.

CLINICAL RELEVANCE

These findings suggest a possible correlation between hypoxia, apoptosis, and cystogenesis, leading to understand the mechanisms responsible to cystic formation in odontogenic lesions.