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

Ludmila De Faro Valverde,Rosane Borges Dias,Clarissa Araújo Gurgel Rocha,Jean Nunes Santos,Eduardo Antônio Gonçalves Ramos,Vanessa Sousa Nazaré Guimarães,Thiago De Almeida Pereira

doi:10.1007/s13277-015-4763-6

Ludmila De Faro Valverde, Rosane Borges Dias + Show 5 more

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https://doi.org/10.1007/s13277-015-4763-6

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Abstract

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.

Highlights

Electronic supplementary material The online version of this article contains supplementary material, which is available to authorized users.Oral cancer is among the ten most common forms of cancer occurring worldwide
Indian Hedgehog (IHH) was generally seen in the cytoplasm, it was present in the cellular membrane in three (13.64 %) cases
The present results corroborate recently published findings indicating the reactivation of the Hh pathway in oral squamous cell carcinoma (OSCC), which appears to participate in the pathogenesis of this disease [9,10,11, 30]

Summary

Introduction

Electronic supplementary material The online version of this article (doi:10.1007/s13277-015-4763-6) contains supplementary material, which is available to authorized users.Oral cancer is among the ten most common forms of cancer occurring worldwide. In light of the conceptual evolution surrounding the development of malignant neoplasia, with respect to cancer stem cells, the study of embryonic signaling pathways holds great promise, notably as a strategy to identify relevant biomarkers. In this context, dysregulation of the Hedgehog (Hh) embryonic signaling pathway has been associated with the development and progression of a range of human tumors [5,6,7,8]. The abnormal activation of this signaling cascade has previously been described in OSCC [9,10,11]

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