Galectin 3 expression in regional lymph nodes and lymph node metastases of oral squamous cell carcinomas.

BACKGROUND: Neck dissection is standard in surgical management of oral squamous cell carcinomas (oscc). However, the immunologic link between primary tumor and lymph nodes is insufficiently understood. Galectin 3 (Gal3) promotes M2 polarization of macrophages and contributes to immunosuppression. The current study analyzes the association between Gal3 expression in regional lymph nodes of oscc with histomorphologic parameters (T-, N-, L- Pn-stage, grading) of the primary tumor. Additionally, Gal3 expression is correlated with markers of macrophage polarization (M1 vs. M2). METHODS: Preoperative diagnostic biopsies (n = 26), tumor resection specimens (n = 34), tumor-free lymph nodes (n = 28) and lymph node metastases (n = 10) of T1/T2 oscc patients were immunohistochemically analyzed for Gal3 and macrophage marker (CD68, CD11c, CD163 and MRC1) expression. The number of positive cells and the expression ratios were quantitatively assessed. RESULTS: High Gal3 expression in tumor-free regional lymph nodes was significantly (p < 0.05) associated with increased tumor size. The epithelial compartment of lymph node metastases showed a significantly (p < 0.05) increased Gal3 expression compared to biopsies and tumor resection specimens. Cell density of M2 macrophages was significantly (p < 0.05) and positively correlated with the number of Gal3 expressing cells in lymph nodes and tumor specimens. CONCLUSION: Gal3 expression in regional lymph nodes might be associated with oscc progression. The increased Gal3 expression in regional lymph nodes of larger tumors underlines the need of immunomodulatory treatment concepts in early-stage oscc. Blocking of Gal3 might be a therapeutic option in oral cancer.

Macrophage polarization differs between apical granulomas, radicular cysts, and dentigerous cysts.

OBJECTIVES: Apical periodontitis can appear clinically as apical granulomas or radicular cysts. There is evidence that immunologic factors are involved in the pathogenesis of both pathologies. In contrast to radicular cysts, the dentigerous cysts have a developmental origin. Macrophage polarization (M1 vs M2) is a main regulator of tissue homeostasis and differentiation. There are no studies comparing macrophage polarization in apical granulomas, radicular cysts, and dentigerous cysts. MATERIALS AND METHODS: Forty-one apical granulomas, 23 radicular cysts, and 23 dentigerous cysts were analyzed in this study. A tissue microarray (TMA) of the 87 consecutive specimens was created, and CD68-, CD11c-, CD163-, and MRC1-positive macrophages were detected by immunohistochemical methods. TMAs were digitized, and the expression of macrophage markers was quantitatively assessed. RESULTS: Radicular cysts are characterized by M1 polarization of macrophages while apical granulomas show a significantly higher degree of M2 polarization. Dentigerous cysts have a significantly lower M1 polarization than both analyzed periapical lesions (apical granulomas and radicular cysts) and accordingly, a significantly higher M2 polarization than radicular cysts. Macrophage cell density in dentigerous cysts is significantly lower than in the periapical lesions. CONCLUSIONS: The development of apical periodontitis towards apical granulomas or radicular cysts might be directed by macrophage polarization. Radicular cyst formation is associated with an increased M1 polarization of infiltrating macrophages. In contrast to radicular cysts, dentigerous cysts are characterized by a low macrophage infiltration and a high degree of M2 polarization, possibly reflecting their developmental rather than inflammatory origin. CLINICAL RELEVANCE: As M1 polarization of macrophages is triggered by bacterial antigens, these results underline the need for sufficient bacterial clearance during endodontic treatment to prevent a possible M1 macrophage-derived stimulus for radicular cyst formation.

Galectin 3 expression in primary oral squamous cell carcinomas.

BACKGROUND: Immunologic factors can promote the progression of oral squamous cell carcinomas (oscc). The phylogenetic highly conserved protein Galectin 3 (Gal3) contributes to cell differentiation and immune homeostasis. There is evidence that Gal3 is involved in the progression of oscc and influences the regulation of macrophage polarization. Macrophage polarization (M1 vs. M2) in solid malignancies like oscc contributes to tumor immune-escape. However, the relationship between macrophage polarization and Gal3 expression in oscc is not yet understood. The current study analyzes the association between histomorphologic parameters (T-, N-, L- Pn-status, grading) and Gal3 expression resp. the ratio between Gal3 expressing cells and CD68 positive macrophages in oscc specimens. METHODS: Preoperative diagnostic biopsies (n = 26) and tumor resection specimens (n = 34) of T1/T2 oscc patients were immunohistochemically analyzed for Gal3 and CD68 expression. The number of Gal3 expressing cells and the ratio between CD68 and Gal3 expressing cells was quantitatively assessed. RESULTS: In biopsy and tumor resection specimens, the number of Gal3 positive cells as well as the Gal3/CD68 ratio were significantly (p < 0.05) higher in T2 oscc compared to T1 cases. In biopsy specimens, a significantly (p < 0.05) increased Gal3 expression and Gal3/CD68 ratio was associated with the progression marker lymph vessel infiltration (L1). Tumor resection specimens of cases with lymph node metastases (N+) had a significantly (p < 0.05) increased Gal3 expression. Additionally, a high Gal3/CD68 ratio correlated significantly (p < 0.05) with higher grading (G3) in tumor resection specimens. CONCLUSION: High Gal3 expression in oscc is associated with tumor size (T-status) and parameters of malignancy (N-, L-status, grading). Gal3 might contribute to M2 macrophage mediated local immune tolerance. Gal3 expression shows association with prognosis in oscc and represent a potential therapeutic target.

Macrophage and osteoclast polarization in bisphosphonate associated necrosis and osteoradionecrosis.

PURPOSE: Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a complication of antiresorptive therapy with nitrogen-containing bisphosphonates (BP). With various suggestions as to pathogenesis, the etiology of BRONJ is not sufficiently understood. Osteoclasts and their precursors, that is, macrophages, are the main target cells of BP. BP can repolarize regeneration- and healing-associated M2 macrophages towards the tissue destructive M1-type. The current study aims to elucidate differences in macrophage and osteoclast polarization in BRONJ, osteoradionecrosis (ORN) and healthy control specimens. MATERIALS AND METHODS: A total of 39 jaw bone samples (18 BRONJ, 8 ORN and 13 healthy controls) were processed for immunohistochemistry to detect CD68-, CD11c- and CD163-positive cells. Macrophages and osteoclasts were distinguished on the basis of morphological differences. Samples were digitized, and the macrophage and osteoclast cell counts were quantitatively analyzed. RESULTS: In jaw bone affected by BRONJ, a significantly increased macrophage infiltration and M1 polarization of macrophages can be seen. The density of CD68-expressing osteoclasts is significantly increased in BRONJ specimens compared to ORN and to healthy controls. CONCLUSIONS: A bisphosphonate-derived shift of macrophage polarization towards M1-polarized macrophages might impair bone tissue homeostasis and thus contribute to the pathogenesis of BRONJ. The observed increase in osteoclast density might be caused by BP-induced prolonged osteoclast survival.

Prognostic significance of macrophage polarization in early stage oral squamous cell carcinomas.

BACKGROUND: Polarization of tumor infiltrating macrophages is associated with the prognosis of solid malignancies and correlates with the occurrence of lymph node metastases in oral squamous cell carcinomas (oscc). Early stage (T1/T2, N0) oscc are characterized by a good prognosis and can be cured by surgery. The postoperative regime usually contains no adjuvant radio-/chemotherapy. The current pilot study was conducted to elucidate whether macrophage polarization in tumor resection specimens and diagnostic biopsies of early stage oscc is associated with tumor outcome. METHODS: Patients with T1/T2, N0, and R0>5mm oscc without adjuvant therapy and 3-year follow-up after tumor resection were retrospectively selected. Tissue microarrays (TMA) containing diagnostic biopsies (n=17) and tumor resection specimens (n=17) were processed for immunohistochemistry in this pilot study to detect CD68-, CD11c-, CD163- and MRC1-positive macrophages. Samples were digitized, and the expression of macrophage markers was quantitatively analyzed. RESULTS: High infiltration of M2 polarized macrophages correlated with poor tumor outcome in early stage (T1/T2, N0) oscc. This correlation was observed in tumor resection specimens, but was also observed in diagnostic biopsies. M2 macrophage polarization in biopsies - but not in tumor resection samples - correlated with high scores in tumor grading. CONCLUSION: Macrophage polarization in early stage oscc is a potential prognostic marker for tumor outcome. The correlation of M2 polarized macrophages with tumor outcome can already be detected in the initial biopsies. Furthermore, M2 polarization of macrophages in biopsies is associated with an increased dedifferentiation.

Increased malignancy of oral squamous cell carcinomas (oscc) is associated with macrophage polarization in regional lymph nodes - an immunohistochemical study.

BACKGROUND: It is largely accepted that specific immunological parameters in solid malignancies are associated with patient's prognosis. Recently a correlation of macrophage polarization with histomorphological parameters could also be shown in oral squamous cell carcinoma (oscc). The observed tumor derived peripheral immune tolerance could be associated with the macrophage polarization in regional tumor draining lymph nodes.So far there are no studies analyzing the macrophage polarization in cervical lymph nodes of oscc patients. In the present study we aimed to correlate macrophage polarization in different anatomical lymph node compartments of patients diagnosed with oscc with histopathologic parameters of the primary tumor (T-, N-, L-, V-, Pn-status, grading). METHODS: Tumor free (n = 37) and metastatic (n = 17) lymph nodes of T1 and T2 oscc patients were processed for immunohistochemistry to detect CD68, CD11c, CD163 and MRC1 positive cells. Samples were digitized using whole slide imaging and the number of cells expressing the aforementioned markers in the region of interest quantitatively analyzed. RESULTS: The malignancy of the primary tumor (defined by T-, L-, Pn-status, grading) correlated with the lymph node macrophage polarization. L1 and Pn1 tumor cases displayed a significantly (p < 0.05) decreased M1 and increased M2 polarization in the sinus of the lymph nodes. G3 cases presented a significantly (p < 0.05) increased M2 polarization in the sinus compared to G2 cases. T2 tumors had significantly (p < 0.05) increased M2 polarization in the interfollicular zone of regional lymph nodes compared to T1 tumors. Metastatic and non-metastatic lymph nodes did not differ regarding their macrophage polarization. CONCLUSIONS: The current study revealed for the first time an influence of oscc on the macrophage polarization in regional lymph nodes. Markers of malignant behavior in the primary tumor were associated with a shift of macrophage polarization in lymph nodes from the anti-tumoral M1 type to the tumor-promoting M2 type. As tumor free and metastatic lymph nodes did not differ in terms of their macrophage polarization pattern, there must be other factors influencing the location for lymph node metastasis formation.

Small oral squamous cell carcinomas with nodal lymphogenic metastasis show increased infiltration of M2 polarized macrophages--an immunohistochemical analysis.

BACKGROUND: In solid malignancies the influence of immunological parameters - especially of macrophages - on invasiveness, metastatic potential and prognosis has been shown. There are no studies quantitatively analysing the macrophage polarization in oral squamous cell carcinoma (oscc). The aim of this study was to correlate macrophage polarization in the epithelial and stromal compartment of oscc with histopathologic parameters. METHODS: T1 and T2 oscc samples (n = 34) were used. Automated immunohistochemical staining detected CD68, CD11c, CD163 and MRC1 positive cells. All samples were completely digitalized using whole slide imaging and the number of stained cells per area was assessed quantitatively. RESULTS: Primary tumours with lymphogenic metastasis (N+) showed a significantly (p < 0.05) increased count of CD68, CD11c, CD163 and MRC1 positive cells in the epithelial fraction compared to N0 tumours. The ratio of CD163 positive cells (M2 macrophages) to CD68 positive cells (M1 and M2 macrophages) was significantly (p < 0.05) increased in N+ tumours. CONCLUSION: An increased macrophage infiltration and an increased M2 polarization in primary oral squamous cell carcinomas with lymphogenic metastasis was shown. Macrophages that migrated into the epithelial tumour fraction seem to be of special biological importance. The results indicate a central role of macrophages in the progression of oscc.

Osteo-radio-necrosis (ORN) and bisphosphonate-related osteonecrosis of the jaws (BRONJ): the histopathological differences under the clinical similarities.

OBJECTIVES: Both osteoradionecrosis (ORN) and bisphosphonate associated osteonecrosis of the jaws (BRONJ) present clinically as regions of exposed necrotic bone. The study aimed to demonstrate the histopathological differences behind the observed clinical similarities. STUDY DESIGN: Ten ORN specimens and ten BRONJ specimens were used, as well as ten samples of normal mandibular bone as control. Two bone-specific stainings were used, i.e. Sirius Red for the study of the relative presence of collagen types I and III and toluidine blue for the study the osteon density. RESULTS: The Red Green Blue (RGB)-analysis of the specimens stained with Sirius Red identified significant differences between the chromatic patterns observed in bone preparations of patients suffering from ORN when compared to both BRONJ and control samples. Moreover, the osteon density of the BRONJ samples was significantly lower when compared to ORN and normal bone samples. CONCLUSIONS: The demonstrated differences in the bone architecture and in the bone collagen content between the two pathological conditions most likely reflect underlying pathophysiological differences.