Browsing by Author "Savin, S. (35568292500)"

The aim of this study was to gain better insight into molecular changes which reflect disturbances in the balance between proliferation and apoptosis during progression of thyroid malignancy from papillary microcarcinoma (PMC) via clinically manifest papillary carcinoma (PTC) to anaplastic carcinoma (ATC). The apoptosis related molecules (Bcl-2, Bax) and proliferation related marker (PCNA) were analysed immunohistochemically in 120 archival cases comprising PMC (n=34), PTC (n=52) and ATC (n=34). In addition, in situ apoptotic cell death was analysed by the TUNEL method. The average Bcl-2 staining score did not differ between PMC and PTC (p>0.05), but was significantly lower in ATC (p<0.05). The Bax score was higher in PTCs and ATCs than in PMCs (p<0.05). Due to these changes, the Bcl-2/Bax ratio showed a marked decrease from PMC to ATC (p<0.05), while proliferation activity increased significantly from PTC to ATC (p<0.05). Despite high Bax expression, the rate of apoptotic cell death was low in the investigated carcinomas, especially in ATC, i.e. the increase in proliferative activity was not counterbalanced with appropriate cell death. Differences were found in the expression of apoptotic molecules (Bcl-2 and Bax), their ratio (Bcl-2/Bax) and in the rate of apoptotic cell death and proliferative activity between PMC, PTC and ATC, indicating that disturbances in the balance between apoptosis and proliferation, in favour of the latter, occur gradually during the progression of malignancy in thyroid tumours. ©2009 European Journal of Histochemistry.

The aim of this study was to gain better insight into molecular changes which reflect disturbances in the balance between proliferation and apoptosis during progression of thyroid malignancy from papillary microcarcinoma (PMC) via clinically manifest papillary carcinoma (PTC) to anaplastic carcinoma (ATC). The apoptosis related molecules (Bcl-2, Bax) and proliferation related marker (PCNA) were analysed immunohistochemically in 120 archival cases comprising PMC (n=34), PTC (n=52) and ATC (n=34). In addition, in situ apoptotic cell death was analysed by the TUNEL method. The average Bcl-2 staining score did not differ between PMC and PTC (p>0.05), but was significantly lower in ATC (p<0.05). The Bax score was higher in PTCs and ATCs than in PMCs (p<0.05). Due to these changes, the Bcl-2/Bax ratio showed a marked decrease from PMC to ATC (p<0.05), while proliferation activity increased significantly from PTC to ATC (p<0.05). Despite high Bax expression, the rate of apoptotic cell death was low in the investigated carcinomas, especially in ATC, i.e. the increase in proliferative activity was not counterbalanced with appropriate cell death. Differences were found in the expression of apoptotic molecules (Bcl-2 and Bax), their ratio (Bcl-2/Bax) and in the rate of apoptotic cell death and proliferative activity between PMC, PTC and ATC, indicating that disturbances in the balance between apoptosis and proliferation, in favour of the latter, occur gradually during the progression of malignancy in thyroid tumours. ©2009 European Journal of Histochemistry.

The expression of galectin-8 (gal-8) has been shown to be altered during neoplastic transformation of certain cell types. This is the first study aimed to analyze the expression of this protein in normal and pathological human thyroid tissue. A total of 41 archival thyroid tissue samples (5 follicular adenomas, 31 papillary carcinomas, 5 follicular carcinomas) together with 36 adjacent hyperplastic or normal thyroid tissues were analyzed by immunohistochemistry. Galectin-8 was expressed in the majority of papillary carcinomas (27/31; 87%). Positive but weaker staining was also found in some of the follicular thyroid carcinomas (2/5; 40%) and adenomas (2/5; 40%). This protein was not detectable in five normal thyroid tissue samples, whereas hyperplastic areas adjacent to tumor were weakly positive in 9 out of 31cases (29%). High gal-8 immunostaining in papillary thyroid carcinoma indicates that gal-8 may potentially serve as a marker of papillary thyroid carcinoma. However, it does not seem to be helpful in the differential diagnostics of follicular carcinoma and adenoma. Further studies are required to determine biological functions and molecular mechanisms underlying the increased expression of gal-8 protein in thyroid lesions, particularly, in papillary thyroid carcinoma. © 2008 Humana Press Inc.

The expression of galectin-8 (gal-8) has been shown to be altered during neoplastic transformation of certain cell types. This is the first study aimed to analyze the expression of this protein in normal and pathological human thyroid tissue. A total of 41 archival thyroid tissue samples (5 follicular adenomas, 31 papillary carcinomas, 5 follicular carcinomas) together with 36 adjacent hyperplastic or normal thyroid tissues were analyzed by immunohistochemistry. Galectin-8 was expressed in the majority of papillary carcinomas (27/31; 87%). Positive but weaker staining was also found in some of the follicular thyroid carcinomas (2/5; 40%) and adenomas (2/5; 40%). This protein was not detectable in five normal thyroid tissue samples, whereas hyperplastic areas adjacent to tumor were weakly positive in 9 out of 31cases (29%). High gal-8 immunostaining in papillary thyroid carcinoma indicates that gal-8 may potentially serve as a marker of papillary thyroid carcinoma. However, it does not seem to be helpful in the differential diagnostics of follicular carcinoma and adenoma. Further studies are required to determine biological functions and molecular mechanisms underlying the increased expression of gal-8 protein in thyroid lesions, particularly, in papillary thyroid carcinoma. © 2008 Humana Press Inc.

Aims: Galectin-3 is a beta-galactoside binding protein involved in multiple biological processes through interactions with complementary glycoconjugates. We analysed the expression and coexpression of galectin-3 and carcinoembryonic antigen (CEA), one of the putative galectin-3 ligands, in medullary thyroid carcinoma (MTC). Methods and results: An immunohistochemical study using monoclonal antibodies was performed on paraffin sections of 20 cases of sporadic MTC comprising 10 cases without and 10 cases with lymph node metastases at the time of surgery. CEA expression was found in all tumours, distributed predominantly in the cytoplasm and occasionally at the cell surface. In the majority of cases (18/20) moderate to strong intensity of staining was found in most of the cells. Positive cytoplasmic staining for galectin-3 was found in 16/20 cases, but varied in intensity and distribution from weak/focal (7/16) to moderate (7/16) or strong (2/16). More intense staining for galectin-3 was mainly associated with MTC cases involving lymph node metastases. Eight out of these 10 cases showed moderate to strong galectin-3 expression concomitant with CEA expression throughout the tumour tissue. Conclusions: These findings suggest that galectin-3 might play a role in the pathobiology of MTC. Simultaneous expression of galectin-3 and CEA in the same tumour cells at an advanced stage of MTC indicates the possibility of their autocrine cooperation during tumour progression.

Background and aim: To examine the relationship between galectin-3 and cell proliferation in thyroid tumor tissue. Galectin-3, a beta-galactoside binding protein, has recently been recognized as a promising molecular marker of thyroid malignancy, due to its high expression in thyroid carcinomas and absence from normal or benign thyroid tissue. However, its exact role in thyroid tumor biology is still unknown. Patients and methods: We examined the relationship between galectin-3 and cell proliferation by comparative immunostaining for galectin-3 and proliferating cell nuclear antigen (PCNA) in paraffin-embedded tissues from 126 cases of papillary thyroid carcinoma. Results: Positive cytoplasmic immunostaining for galectin-3 was found in 115 (91.3%) cases. Nuclear staining for PCNA was detectable in 93 (74.4%) cases. A low level of PCNA staining (less than 10% positive cells) was found in 36 (28.6%) cases, moderate staining for PCNA (more than 10% but less than 30% positive cells) in 35 cases (27.8%), while highly increased PCNA expression (more than 30% positive cells) was found in 32 (25.4%) cases. Moderate or strong galectin-3 expression, found in 99 cases, was associated with highly increased PCNA staining in 28.3% of them but with no detectable PCNA expression in 24.3% of them. Conclusion: These results suggest that overexpression of galectin-3 is not clearly related to proliferative activity of papillary thyroid carcinoma cells as assessed by PCNA immunostaining.

Background and aim: To examine the relationship between galectin-3 and cell proliferation in thyroid tumor tissue. Galectin-3, a beta-galactoside binding protein, has recently been recognized as a promising molecular marker of thyroid malignancy, due to its high expression in thyroid carcinomas and absence from normal or benign thyroid tissue. However, its exact role in thyroid tumor biology is still unknown. Patients and methods: We examined the relationship between galectin-3 and cell proliferation by comparative immunostaining for galectin-3 and proliferating cell nuclear antigen (PCNA) in paraffin-embedded tissues from 126 cases of papillary thyroid carcinoma. Results: Positive cytoplasmic immunostaining for galectin-3 was found in 115 (91.3%) cases. Nuclear staining for PCNA was detectable in 93 (74.4%) cases. A low level of PCNA staining (less than 10% positive cells) was found in 36 (28.6%) cases, moderate staining for PCNA (more than 10% but less than 30% positive cells) in 35 cases (27.8%), while highly increased PCNA expression (more than 30% positive cells) was found in 32 (25.4%) cases. Moderate or strong galectin-3 expression, found in 99 cases, was associated with highly increased PCNA staining in 28.3% of them but with no detectable PCNA expression in 24.3% of them. Conclusion: These results suggest that overexpression of galectin-3 is not clearly related to proliferative activity of papillary thyroid carcinoma cells as assessed by PCNA immunostaining.

Aims: Galectin-3 is a β-galactoside binding protein, recently recognized as a promising molecular marker of thyroid malignancy. As reported in several studies, galectin-3 is highly expressed in papillary thyroid carcinoma, but its expression has not been investigated in papillary microcarcinoma, which is a variant of papillary thyroid carcinoma. Methods and results: Using a monoclonal antibody to galectin-3 and the avidin-biotin-peroxidase complex (ABC) immunohistochemical technique, we analysed galectin-3 expression in 63 cases of papillary microcarcinoma. The results showed immunohistochemical reactivity for galectin-3 in 51 (80.9%) cases. Intensity of staining varied from strong or moderate to weak. Galectin-3 localization was mostly cytoplasmic, but also membranous or nuclear in some cells. Immunohistochemical expression of galectin-3 was not found in 12 (19.1%) cases. Most galectin-3 negative microcarcinomas (10/12) were of the non-classical type, i.e. without papillary architecture. Neither the frequency nor the intensity of a positive reaction was related to tumour size. Conclusions: Galectin-3 gene is expressed at the protein level in most papillary microcarcinomas, although with slightly lower frequency than that reported for clinically evident papillary thyroid carcinoma. The presence of galectin-3 in clinically silent microcarcinomas may indicate that galectin-3 is not related to growth or aggressiveness of papillary thyroid microcarcinomas but rather plays some other role in thyroid tumour biology. © 2005 Blackwell Publishing Limited.

Aim: Expression of thyroid peroxidase (TPO) in the thyroid gland tissue is well known as a sensitive marker of the thyroid malignancy. We have evaluated immunohistochemical assay of TPO for distinguishing follicular thyroid carcinoma from follicular adenoma. Materials and Methods: Sections of formalin-fixed tissues obtained from 92 patients with thyroid tumors (52 follicular carcinomas and 40 follicular adenomas including the Hürthle cell type) were analyzed using a monoclonal antibody (TPO mAb 47) and the avidin-biotin peroxidase complex immunohistochemical technique. Lesions with staining of more than 80% of the follicular cells/specimen were considered benign, while less than 80% were considered malignant. Results: TPO immunostaining correlated with the histopathological diagnosis in 24/40 cases of follicular adenomas and 41/52 cases of follicular carcinomas, giving a specificity of 60% and a sensitivity of 79%. Conclusion: These results suggest that immunohistochemical assay of TPO expression has limited value for the differential diagnosis of follicular thyroid carcinoma from thyroid follicular adenoma.

Aim: Expression of thyroid peroxidase (TPO) in the thyroid gland tissue is well known as a sensitive marker of the thyroid malignancy. We have evaluated immunohistochemical assay of TPO for distinguishing follicular thyroid carcinoma from follicular adenoma. Materials and Methods: Sections of formalin-fixed tissues obtained from 92 patients with thyroid tumors (52 follicular carcinomas and 40 follicular adenomas including the Hürthle cell type) were analyzed using a monoclonal antibody (TPO mAb 47) and the avidin-biotin peroxidase complex immunohistochemical technique. Lesions with staining of more than 80% of the follicular cells/specimen were considered benign, while less than 80% were considered malignant. Results: TPO immunostaining correlated with the histopathological diagnosis in 24/40 cases of follicular adenomas and 41/52 cases of follicular carcinomas, giving a specificity of 60% and a sensitivity of 79%. Conclusion: These results suggest that immunohistochemical assay of TPO expression has limited value for the differential diagnosis of follicular thyroid carcinoma from thyroid follicular adenoma.