Ana Calado Lopes - Academia.edu (original) (raw)
Papers by Ana Calado Lopes
features description and its relation with grading on 148 rat DMBA-induced mammary tumours". Mous... more features description and its relation with grading on 148 rat DMBA-induced mammary tumours". Mouse models of disease-linking in vivo observations to pathology endpoints. Wellcome Trust Conference Centre,
Pathology - Research and Practice, 2017
Chemically-induced mammary tumors in rats by the carcinogens 1-methyl-1-nitrosourea-(MNU) and 7,1... more Chemically-induced mammary tumors in rats by the carcinogens 1-methyl-1-nitrosourea-(MNU) and 7,12-dimethylbenz[a]anthracene (DMBA) are the most widely used models for studies related with human breast cancer. This study aimed to evaluate the immunoexpression of the prognostic factors estrogen receptor ␣ (ER␣), progesterone receptor (PR) and Ki-67, in MNU and DMBA-induced rat mammary tumors, in order to know the model that best suits to woman breast cancer. Twenty-eight MNU-induced and 16 DMBA-induced mammary tumors in virgin female Sprague-Dawley rats were analyzed. The expression of the prognostic markers ER␣, PR and Ki-67 proliferation index (Ki-67 PI) was assessed by immunohistochemistry. Mitotic activity index (MAI) was also evaluated. More than one histological pattern was identified in each mammary tumor. Carcinomas constituted the lesions most frequently induced by both carcinogens: 33 MNU-induced carcinomas and 23 DMBA-induced carcinomas. All MNU and DMBA-induced mammary carcinomas were ER + /PR + , with a higher expression of ER␣ when compared with PR. Tumors' weight, the expression of ER␣, PR, Ki-67 PI and MAI were higher in MNU-induced mammary carcinomas when compared with the DMBA-induced ones. Statistically significant differences between groups were observed for ER␣, PR and MAI (p < 0.05). The higher KI-67 PI and MAI in MNUinduced mammary carcinomas are suggestive of a higher aggressiveness of these carcinomas when compared with the DMBA-induced ones, and consequently a worse response to the therapy and a worse prognosis. In this way, the use of the rat model of MNU-induced mammary tumors is advised in experimental protocols aiming to study more aggressive mammary tumors within the group of double-positive mammary tumors (ER + /PR +).
Experimental and Toxicologic Pathology, 2014
This work aims at characterizing rat mammary tumors induced by 7,12-dimethylbenz(a)anthracene (DM... more This work aims at characterizing rat mammary tumors induced by 7,12-dimethylbenz(a)anthracene (DMBA) and the respective malignancy potential, commonly graded with histopathology features grouped by intensity levels. Tumors were described over fourteen multiple ranged microscopic parameters and a comprehensive characterization of the histological patterns and their relation with tumor grade was carried out by principal component analysis (PCA). The number of histological patterns present on a tumor tends to correlate with malignant features. High grade tumors are characterized by the presence of several structural patterns, with cribriform prevalence and necrosis. The cribriform pattern correlates with grading, i.e., tumors having a higher predominance of the cribriform pattern are likely to be more malignant. The findings may represent a benchmark for similar characterization studies in other models.
features description and its relation with grading on 148 rat DMBA-induced mammary tumours". Mous... more features description and its relation with grading on 148 rat DMBA-induced mammary tumours". Mouse models of disease-linking in vivo observations to pathology endpoints. Wellcome Trust Conference Centre,
Pathology - Research and Practice, 2017
Chemically-induced mammary tumors in rats by the carcinogens 1-methyl-1-nitrosourea-(MNU) and 7,1... more Chemically-induced mammary tumors in rats by the carcinogens 1-methyl-1-nitrosourea-(MNU) and 7,12-dimethylbenz[a]anthracene (DMBA) are the most widely used models for studies related with human breast cancer. This study aimed to evaluate the immunoexpression of the prognostic factors estrogen receptor ␣ (ER␣), progesterone receptor (PR) and Ki-67, in MNU and DMBA-induced rat mammary tumors, in order to know the model that best suits to woman breast cancer. Twenty-eight MNU-induced and 16 DMBA-induced mammary tumors in virgin female Sprague-Dawley rats were analyzed. The expression of the prognostic markers ER␣, PR and Ki-67 proliferation index (Ki-67 PI) was assessed by immunohistochemistry. Mitotic activity index (MAI) was also evaluated. More than one histological pattern was identified in each mammary tumor. Carcinomas constituted the lesions most frequently induced by both carcinogens: 33 MNU-induced carcinomas and 23 DMBA-induced carcinomas. All MNU and DMBA-induced mammary carcinomas were ER + /PR + , with a higher expression of ER␣ when compared with PR. Tumors' weight, the expression of ER␣, PR, Ki-67 PI and MAI were higher in MNU-induced mammary carcinomas when compared with the DMBA-induced ones. Statistically significant differences between groups were observed for ER␣, PR and MAI (p < 0.05). The higher KI-67 PI and MAI in MNUinduced mammary carcinomas are suggestive of a higher aggressiveness of these carcinomas when compared with the DMBA-induced ones, and consequently a worse response to the therapy and a worse prognosis. In this way, the use of the rat model of MNU-induced mammary tumors is advised in experimental protocols aiming to study more aggressive mammary tumors within the group of double-positive mammary tumors (ER + /PR +).
Experimental and Toxicologic Pathology, 2014
This work aims at characterizing rat mammary tumors induced by 7,12-dimethylbenz(a)anthracene (DM... more This work aims at characterizing rat mammary tumors induced by 7,12-dimethylbenz(a)anthracene (DMBA) and the respective malignancy potential, commonly graded with histopathology features grouped by intensity levels. Tumors were described over fourteen multiple ranged microscopic parameters and a comprehensive characterization of the histological patterns and their relation with tumor grade was carried out by principal component analysis (PCA). The number of histological patterns present on a tumor tends to correlate with malignant features. High grade tumors are characterized by the presence of several structural patterns, with cribriform prevalence and necrosis. The cribriform pattern correlates with grading, i.e., tumors having a higher predominance of the cribriform pattern are likely to be more malignant. The findings may represent a benchmark for similar characterization studies in other models.