Expression of invadopodia markers can identify oral lesions with a high risk of malignant transformation

Abstract

Oral squamous cell carcinoma (OSCC) is the most common malignant tumor of the oral cavity and is usually preceded by a range of premalignant tissue abnormalities termed oral potentially malignant disorders. Identifying malignant transformation is critical for early treatment and consequently improved survival and decreased morbidity. Invadopodia (INV) are specialized subcellular structures required for cancer cell invasion. We developed a new method to visualize INV in keratinocytes using fluorescent immunohistochemistry (FIHC) and semi‐automated images analysis. The presence of INV was used to determine the risk of malignant transformation. We analyzed 145 formalin‐fixed, paraffin‐embedded (FFPE) oral biopsy samples from 95 patients diagnosed as nondysplastic, dysplastic, and OSCC including 49 patients whose lesions transformed to OSCC (progressing) and 46 cases that did not transform to OSCC (control). All samples were stained for Cortactin, tyrosine kinase substrate with five SH3 domains (Tks5) and matrix metallopeptidase 14 (MMP14) using FIHC, imaged using confocal microscopy and analyzed using a multichannel colocalization analysis. The areas of colocalization were used to generate an INV score. Using the INV score, we were able to identify progressing lesions with a sensitivity of 75–100% and specificity of 72–76%. A positive INV score was associated with increased risk of progression to OSCC. Our results suggest that INV markers can be used in conjunction with the current diagnostic standard for early detection of OSCC.

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

“…Indeed, invadopodia is present not only in established SCC, but its expression is also seen in premalignant nondysplastic and dysplastic lesions. Ali et al showed that progressing premalignant lesions that evolved to SCC have higher invadopodia scores, which were based on invadopodia markers, than non-progressing lesions [ 41 ]. This finding places invadopodia as an important marker for predicting malignant transformation and a potential determinant of treatment, where high-risk cases could require further aggressive treatment.…”

“…A TNF-driven oral inflammation promotes a pro-inflammatory environment and proinvasion phenotype leading to the recruitment and activation of inflammatory cells and invadopodia formation [ 42 ]. An increase in local neutrophil infiltration is seen in aggressive cases with decreased survival rate [ 42 ] and also in progressing cases that undergo malignant transformation [ 41 ]. The identification of invadopodia promotors and regulators are quite important and can be a target for specific drugs development and anticancer therapy [ 43 ].…”

TNFα Signaling Is Increased in Progressing Oral Potentially Malignant Disorders and Regulates Malignant Transformation in an Oral Carcinogenesis Model

“…Ten images were acquired from multiple regions of each tissue section using the SP8 confocal microscope (Leica) for human samples and the Quorum Spinning Disk confocal microscope (Quorum Technologies Inc.) for mouse specimens. Data analysis was performed using Volocity Image Analysis Software (PerkinElmer) using a custom protocol that detected positive expression based on fluorescent intensity and area for both human and mouse specimens ( 26 ). Identification of morphological features within each tissue section was accomplished using DAPI.…”

PLXDC2 Enhances Invadopodium Formation to Promote Invasion and Metastasis of Gastric Cancer Cells via Iteracting with PTP1B

“…The invadepodia were defined as the yellow spot of MMP14, a marker of invadopodium [19], co-locating with F-actin.…”