An adapted tissue microarray for the development of a matrix arrangement of tissue samples

A handcrafted tissue microarray for a matrix arrangement of tissue samples

INTRODUCTION

Tissue microarray (TMA) was first designed to enable more efficient immunohistochemical screening of antibodies and tissues. However, due to the high cost of commercial TMA builder instrument, such method is not affordable for many pathology laboratories. Then, methodological adaptations have been proposed in order to reduce TMA-associated cost.

METHODS

A manual leather puncher with an inner diameter of 2mm was used to collect a tissue sample from the donor paraffin block. The conventional TMA method was adopted as a control group.

RESULTS

Empty paraffin recipient blocks were prepared and a standard 2-mm crochet needle was used to create 24 equidistant holes in the recipient block. Tissue cores obtained from the donor blocks were transferred to the holes in the recipient blocks and routine histopathological techniques were then performed.

DISCUSSION

In this study we proposed a new approach to produce TMA recipient blocks as an alternative to the conventional TMA.

Immunoexpression of metalloproteinases 2 and 14 and TIMP-2 inhibitor in main types of primary gastric carcinomas and lymph node metastasis

Metalloproteinase-2 (MMP-2) and -14 (MMP-14) and the tissue inhibitor of metalloproteinases type 2 (TIMP-2) participate in epithelial-mesenchymal transition and tumor progression in many cancers. However, the correlation between these enzymes in gastric cancer and the metastatic potential to their respective lymph node needs to be determined. Here, we evaluated the expression of these enzymes in gastric carcinoma and lymph node metastases and their possible involvement in tumor progression. Histological samples from 83 patients with gastric cancer and their respective lymph nodes were used. MMP-2, MMP-14 and TIMP-2 immunoexpression was scored. TIMP-2 expression in tumor-associated macrophages occurred more frequently than in normal mucosa (P = 0.0128). Female tumor samples presented higher MMP-2 expression (P = 0.0248), while TIMP-2 occurred mainly in patients over 50 years old (P = 0.0034). MMP-2 was higher expressed in primary tumor macrophages than in neoplastic cells (P = 0.0118), and was also seen in macrophages from metastatic-affected lymph nodes of intestinal and diffuse histotypes (P = 0.0006). MMP-2, MMP-14 and TIMP-2 expression in mononuclear cells might be correlated with progression of gastric cancer. MMP-14 production by macrophages appears to be more involved in diffuse gastric cancer progression.