Expression of Prostate-Specific Membrane Antigen (PSMA) in Brain Glioma and its Correlation with Tumor Grade.

BACKGROUND & OBJECTIVE: Angiogenesis is an essential component of tumor growth. Expression of PSMA on the neo-vasculature of many solid tumors, including glioblastoma multi-form, has been determined. The pattern of expression suggests that PSMA may play a functional role in angiogenesis. METHODS: expression of PSMA in different grades of brain glioma was evaluated by the immunohistochemistry method to determine the probable usefulness of anti-PSMA antibody as complementary target therapy in different grades of glioma. RESULTS: Overall, 72 cases of low (grade I and II) and high (grade III and IV) grade gliomas were evaluated for expression of PSMA. Positive PSMA staining was observed in 12 (33.3%) of high grade and 3 (8.3%) of low grade gliomas. Although, high grade tumors more commonly had positive result for PSMA (P value=0.009), the intensity of staining was significantly stronger in low-grade tumors (P value=0.009). CONCLUSION: Expression of PSMA in different grades of glioma might provide a basis for further investigations focusing on selective target therapy in combination with the current standard care in all glioma grades, to improve treatment efficacy.

Evaluation of MMP2 and Caspase-3 expression in 107 cases of papillary thyroid carcinoma and its association with prognostic factors.

Papillary thyroid carcinoma (PTC), including its variants and widely varying behavior, constitutes about 80% of all thyroid malignancies. Increased knowledge regarding molecular alterations has led to attempts to identify diagnostic or prognostic factors for a reliable preoperative approach to the classification of patients according to risk of recurrence. In this study, 107 cases of PTC with known histological properties, including vascular or capsular invasion, were assessed for expression of MMP2 and Caspase-3 using immunohistochemistry. Considering 10% as a cutoff to discriminate cases with invasive behavior from the non-invasive group, there was no relationship between expression of MMP2 or Caspase-3 in tumor cells and the presence of capsular invasion (p=0.45 and 0.64, respectively), as well as for the expression of Caspase-3 and vascular invasion (p=0.43). In case of MMP2, a borderline correlation was found between the positive reaction of tumor cells with the presence of vascular invasion (p=0.05). So the evaluation of MMP2 in thyroid PTC appears to be of some benefit to the prediction of tumor behavior while Caspase-3 as a marker of prediction seems to be of no use.

Expression of galectin-3, nm-23, and cyclooxygenase-2 could potentially discriminate between benign and malignant pheochromocytoma.

Currently, the only reliable indicator of malignancy in pheochromocytoma is the presence of distant metastasis or extensive local invasion; predicting behavior of pheochromocytoma remains challenging. We aimed to correlate the behavior of pheochromocytoma with its expression of nm-23, cyclooxygenase (COX)-2, and galectin-3 (genes used to predict the course of some neoplastic diseases), evaluated immunohistochemically in 55 paraffin blocks of formalin-fixed pheochromocytoma specimens with confirmed behavior. In 3 (7%) of 44 benign and 7 (64%) of 11 malignant pheochromocytomas, there was negative nm-23 expression (P = .000). COX-2 immunoreactivity was positive in 10 (23%) of benign and 9 (82%) of malignant tumors (P = .000). Galectin-3 was expressed in 5 (11%) of benign and 9 (82%) of malignant pheochromocytomas (P = .000). Negative nm-23, along with positive COX-2 or galectin-3, predicted malignancy with 100% specificity. Dual negativity for galectin-3 and COX-2, along with nm-23 positivity, indicated benign behavior with 100% sensitivity. In early pheochromocytoma, evaluation of nm-23, galectin-3, and COX-2 expression could predict the outcome. Larger studies seem necessary to confirm the potential practical value of our findings.

Immunohistochemical expression of Ki67, c-erbB-2, and c-kit antigens in benign and malignant pheochromocytoma.

In this study, we evaluated the immunohistochemical expression and the possible advantages of Ki67 antigen, c-erbB-2, and c-kit proto-oncogenes in the differentiation between benign and malignant pheochromocytomas. Paraffin-embedded tissue blocks from 44 benign (35 adrenal and 9 extra-adrenal) and 11 malignant (9 adrenal and 2 extra-adrenal) cases of pheochromocytoma were selected for immunohistochemical staining using antibodies against Ki67, c-erbB-2, and c-kit antigens. We investigated the relationship between the expression of these antigens and age, gender, tumor size, histologic patterns and necrosis, as well as tumor behavior. The risk of malignancy was higher when tumor size was increased. We found out that more uncommon tissue patterns, such as small cell and spindle cell patterns, are mostly indicators of malignancy. There was a statistically significant relationship between Ki67- and c-erbB-2-positive staining of the tumor cells and the malignant behavior of the pheochromocytomas (p-value=0.000), while cytoplasmic c-kit staining did not show any correlation with tumor malignancy (p-value=0.087). We concluded that tumor size and the histomorphologic patterns (spindle cell and small round cell) are significantly associated with tumor behavior. In addition, Ki67 positivity and c-erbB-2 expression can be used as immunohistochemical markers for predicting the malignant behavior of pheochromocytoma.