Hedgehog pathway activation in oral squamous cell carcinoma: cancer-associated fibroblasts exhibit nuclear GLI-1 localization.

The purpose of this study was to evaluate the expression of Hedgehog (HH) signaling molecules (SHH and GLI-1) by cancer-associated fibroblasts (CAF) in oral squamous cell carcinoma (OSCC). Immunohistochemistry was used to detect molecular HH signaling and CAF-related protein expression, including α-SMA and S100A4, in 70 samples of human OSCC. The colocalization of α-SMA and S100A4 with SHH was also evaluated by double-staining. In vitro study was performed using primary normal oral fibroblast (NOF) and CAF through immunofluorescence and Western Blot for CAF-proteins, SHH, and GLI-1. Forty-five cases (64.28%) were positive for α-SMA exclusively in tumor stroma, and S100A4 was identified in the cytoplasm of CAFs in 94.28% (n = 66) of the cases. With respect to stromal cells, 64 (91.43%) OSCC cases were positive for SHH, and 31 were positive for GLI-1 (44.29%); positive correlations were found between SHH and α-SMA (p < 0.0001, φ = 0.51), as well as between SHH and S100A4 (p = 0.087, φ = 0.94). Protein expression of SHH and GLI-1 was observed in primary CAFs and NOFs. Although SHH was found to be localized in the cellular cytoplasm of both cell types, GLI-1 was present only in the nuclei of CAF. Our results indicate that CAFs are not only potential sources of HH ligands in tumor stroma, but may also respond to HH signaling through nuclear GLI-1 activation. We further observed that elevated SHH expression by OSCC cells was associated with higher CAF density, reinforcing the chemoattractant role played by these molecules.

Canalis Sinuosos mimetizando reabsorção radicular: relato de caso / Canalis sinuosus mimicking root resorption: case report

Relato de caso: Relatar um caso de canal acessório do Canalis Sinuosos, localizado por palatino à raiz do dente 21 que, na radiografia panorâmica, foi observada como uma área radiolúcida sobreposta aos terços médio-apical dente 21, indicando reabsorção radicular, sendo indispensável uma investigação acurada por tomografia computadorizada de feixe cônico (TCFC). Conclusão: A TCFC se mostrou eficiente na identificação do Canalis Sinuosos em relação à radiografia panorâmica, possibilitando um correto diagnóstico para o caso.

Case report: This report describes a case of Canalis sinuosus accessory canal, lingually to the root of the tooth 21, that was observed on panoramic radiograph as a radiolucent area superimposed over the middle and apical thirds, indicating root resorption. However, cone-beam computed tomography (CBCT) recommended for an accurated diagnosis of the case disclose the presence of this anatomic variation. Conclusion: CBCT was more accurate in detection of Canalis sinuosus than panoramic radiography.

Macrophages and endothelial cells orchestrate tumor-associated angiogenesis in oral cancer via hedgehog pathway activation.

The present study aimed to evaluate the role of Hedgehog (Hh) molecule expression in association with the clinical aspects of oral squamous cell carcinoma (OSCC), as well as angiogenesis and CD163+ macrophages. Twenty-eight cases of OSCC, nine cases of tumor-free resection margins (TM), and four cases of non-neoplastic oral mucosa (NNM) were submitted to immunohistochemistry to detect proteins Sonic Hedgehog (SHH), Indian Hedgehog (IHH), GLI1, CD163, and CD105. Protein colocalization with respect to SHH/CD163, IHH/CD163, GLI1/CD163, and GLI1/CD105 was assessed by immunohistochemical double staining. In tumor parenchyma, SHH and IHH were present in the cytoplasm of neoplastic cells, while GLI1 was observed in cytoplasm and nucleus. Endothelial cells were found to express SHH, IHH, and GLI1 within CD105+ vessels, and a positive correlation between infiltrating macrophage density (IMD) and microvascular density (MVD) was observed in cases of OSCC and TM. When compared to TM and NNM, the OSCC cases demonstrated higher immunoreactivity for SHH (p = 0.01), IHH (p = 0.39), GLI1 (p = 0.03), IMD (p = 0.0002), and MVD (p = 0.0002). Our results suggest the participation of the Hh pathway in OSCC by way of autocrine and paracrine signaling, in addition to the participation of both SHH and IHH ligands. Endothelial cells were also found to exhibit positivity with respect to Hh pathway components and we surmise that these molecules may play a role in tumor angiogenesis. CD163+ macrophages were also observed to express IHH, a ligand of this pathway, in addition to being associated with tumor neovascularization.

Enhanced Expression of Hedgehog Pathway Proteins in Oral Epithelial Dysplasia.

The aim of this study was to characterize the profile of the proteins involved in the Hedgehog signaling pathway to aid in the understanding of the pathogenesis of oral epithelial dysplasia (OED). The proteins SHH, PTCH1, HHIP, SUFU, GLI1, and cyclin D1 were evaluated by immunohistochemistry in 25 cases of OED, 4 of non-neoplasic oral mucosa, 8 of inflammatory fibrous hyperplasia and 5 of hyperkeratosis. SHH proteins were predominant in OED cases. Although PTCH1 protein was observed in all cases, this molecule was more highly expressed in OED. The inhibitor protein SUFU was present in OED and HHIP protein was overexpressed in OED. GLI1 proteins were predominantly found in the nuclei of epithelial cells in OED. Basal and suprabasal cells in the epithelial lining were positive for cyclin D1 only in OED. In conclusion, comparative analysis of the proteins involved in the Hedgehog pathway suggests that enhanced expression of these proteins can play an important role in the biological behavior of OED.