Immunohistochemical expression of SPARC in odontogenic keratocysts: a comparative study with other odontogenic cysts.

BACKGROUND: Secreted protein acidic and rich in cysteine (SPARC) has been shown to modulate aggressive behavior in several benign and malignant tumors. Little is known about SPARC expression in odontogenic keratocyst (OKC), an odontogenic cyst with an aggressive nature. To the best of our knowledge, only one study has been investigated the expression of this protein in OKCs. This study aimed to characterize SPARC expression in OKCs. Additionally, to determine whether SPARC is associated with aggressive behavior in OKCs, SPARC expression in OKCs was compared with radicular cysts (RCs), dentigerous cysts (DCs) and calcifying odontogenic cysts (COCs). These odontogenic cysts showed no or less aggressive behavior. METHODS: SPARC expression was evaluated in 38 OKCs, 39 RCs, 35 DCs and 14 COCs using immunohistochemistry. The percentages of positive cells and the intensities of immunostaining in the epithelial lining and the cystic wall were evaluated and scored. RESULTS: Generally, OKCs showed similar staining patterns to RCs, DCs and COCs. In the epithelial lining, SPARC was not detected, except for ghost cells in all COCs. In the cystic wall, the majority of positive cells were fibroblasts. Compared between 4 groups of odontogenic cysts, SPARC expression in OKCs was significantly higher than those of RCs (P < 0.001), DCs (P < 0.001) and COCs (P = 0.001). CONCLUSIONS: A significant increase of SPARC expression in OKCs compared with RCs, DCs and COCs suggests that SPARC may play a role in the aggressive behavior of OKCs.

Preliminary Study on the Expression of CLLD7 and CHC1L Proteins in Oral Squamous Cell Carcinoma.

OBJECTIVE: This study aimed to preliminarily evaluate the expression of two putative tumor suppressor proteins, including chronic lymphocytic leukemia deletion gene 7 (CLLD7) and chromosome condensation 1-like (CHC1L) proteins in oral squamous cell carcinoma (OSCC). MATERIALS AND METHODS: Expression of CLLD7 and CHC1L proteins was analyzed in 19 OSCC and 12 normal oral mucosa (NOM) using immunohistochemistry. The percentage of positive cells and intensity of staining were semiquantitatively assessed and expressed with an immunoreactive score. The number of positive cells at various subcellular localizations was evaluated and presented in percentages. The immunoreactivity scores and percentages of positive cells at various localizations were compared between the normal and OSCC groups with statistical significance at p-value less than 0.05. RESULTS: According to immunohistochemical analysis, the immunoreactivity scores for both CLLD7 and CHC1L were higher in NOM than those of OSCC. Analysis of CLLD7 localization revealed predominant nuclear staining at basal and parabasal areas in NOM, whereas more cytoplasmic staining was observed in OSCC. For CHC1L, nuclear staining was prominent in NOM. In contrast, significantly increased plasma membrane staining was detected in OSCC. CONCLUSION: The expression of CLLD7 and CHC1L proteins was reduced in OSCC. Alterations in the subcellular localization of these two proteins in OSCC were also demonstrated. These preliminary results suggest that CLLD7 and CHC1L are aberrantly expressed in OSCC. The precise mechanisms of these putative tumor suppressor proteins in OSCC require future studies.

Polarized Microscopic Analysis of Picrosirius Red Stained Salivary Gland Pathologies: An Observational Study.

OBJECTIVE: Salivary gland diseases and their pathologies may affect the glandular structure including collagen, a major stromal component, in response to tissue damage or diseases. This study aimed to examine the changes in collagens in different salivary gland diseases using polarized picrosirius red staining. MATERIALS AND METHODS: The submandibular gland samples diagnosed as sialadenitis, chronic sclerosing sialadenitis, pleomorphic adenoma, adenoid cystic carcinoma, and mucoepidermoid carcinoma were stained with picrosirius red, Masson's trichrome, and anticollagen I staining. The quantity of collagens was examined and reported as a percentage of positive picrosirius red area. The maturity of collagens was studied with polarized light microscope and reported as a percentage of orange-red and yellow-green polarized collagens, representing the mature and immature collagens, respectively. STATISTICAL ANALYSIS: The % positive areas for picrosirius red representing the collagen amount among salivary gland diseases were analyzed by one-way analysis of variance with Tukey's test. The % orange-red and % yellow-green polarized areas representing the collagen maturity were analyzed by Kruskal-Wallis test and Mann-Whitney U test. RESULTS: The malignant tumors, adenoid cystic carcinoma (29.92) and mucoepidermoid carcinoma (26.59), had higher significant percentage of positive picrosirius red area, compared with the benign tumor (14.56), chronic sclerosing sialadenitis (10.61), and sialadenitis (7.22) (p < 0.05). The percentages of orange-red polarized areas are 48.07, 39.6, 62.67, 83.75, and 76.05 in sialadenitis, chronic sclerosing sialadenitis, pleomorphic adenoma, adenoid cystic carcinoma, and mucoepidermoid carcinoma, respectively. This percentage tended to increase in the benign and malignant lesions with statistical difference, compared with the inflammatory lesions (p < 0.05). There was no statistical difference in the percentages of yellow-green polarized areas among various salivary gland diseases. In addition, the results of Masson's trichrome and anticollagen I staining are corresponding to that of picrosirius red among various salivary gland diseases. CONCLUSIONS: Polarized picrosirius red demonstrated the most amounts of collagen in the malignant lesion, and represented the different maturity of collagens in each lesion group. Studying the amounts and maturity of collagen with picrosirius red for extracellular matrix alteration in salivary gland diseases along with routine hematoxylin and eosin, Masson's trichrome, and immunohistochemistry may provide a better understanding in different salivary gland pathologies.

Epithelial and fibroblast SPARC expression patterns in oral leukoplakia and oral squamous cell carcinoma.

OBJECTIVE: This study evaluated and compared the expression of secreted protein acidic and rich in cysteine (SPARC) in epithelial cells and fibroblasts of oral leukoplakia (OL) and oral squamous cell carcinoma (OSCC) using normal oral mucosa as a control. STUDY DESIGN: The expression of SPARC was determined in samples of normal oral mucosa (n = 12), OL without dysplasia (n = 31), OL with dysplasia (n = 54), and OSCC (n = 69) using immunohistochemistry. The percentage of positive cells in epithelial cells and fibroblasts was independently evaluated. RESULTS: Epithelial SPARC was found in 33.3%, 35.5%, 25.9%, and 66.7% of normal oral mucosa, OL without dysplasia, OL with dysplasia, and OSCC, respectively. Fibroblast SPARC was found in 50.0%, 29.0%, 46.3%, and 84.1% of normal oral mucosa, OL without dysplasia, OL with dysplasia, and OSCC, respectively. OSCC had higher epithelial and fibroblast SPARC expression than normal oral mucosa, OL without dysplasia, and OL with dysplasia (P < .05). No significant differences were observed in epithelial and fibroblast SPARC among normal oral mucosa or OL with and without dysplasia. CONCLUSION: Overexpression of epithelial and fibroblast SPARC was observed in OSCC but not in OL, suggesting that SPARC is involved in the late stage of oral carcinogenesis.