TACSTD2 / Trop-2 (MSVA-733R)

Recombinant Rabbit monoclonal / IgG 1:100 – 1:200 Research Use Only Cell Surface Human MSVA-733R Cell surface glycoprotein Trop-2; Membrane Component Chromosome 1, Surface Marker 1 (M1S1); Pancreatic Carcinoma Marker Protein GA733-1; TROP2; Tumor-Associated Calcium Signal Transducer 2 (TACSTD2) Liver: A strong membranous Trop-2 immunostaining should be seen in bile ducts. Liver: Hepatocytes should not show any Trop-2 immunostaining. TACSTD2 is a therapeutic target protein Trophoblast cell surface antigen 2 (Trop-2, syn. Tumor-associated calcium signal transducer 2), is a membranous glycoprotein of 40 KDa encoded by the intronless TACSTD2 gene at human chromosome 1p32. The Trop-2 protein is a cell surface receptor composed of a large extracellular domain, a single transmembrane domain, and a short intracellular tail. The main function of the protein is transducing an intracellular calcium signal that is related to cellular growth. In embryonic development, Trop-2 is critical for placental formation, embryo implantation, stem cell proliferation, and organ development. Trop-2 up-regulation has been reported from several cancer types. Consistent with its role in embryogenesis, Trop-2 expression is regulated by several oncogenic transcription factors such as CREB1, NF– κ B, HOXA10, HNF4A, TP63, TP53, ERG, HNF1A/TCF-1, and FOXP3. Trop-2 knock-out cells show a disturbed proliferation while overexpression of Trop-2 accelerates the cancer cell cycle and drives c... Trop2 staining pattern in Normal Tissues with antibody MSVA-733R (images are shown in our “Normal Tissue Gallery”) Brain Cerebrum Negative. Cerebellum Negative. Endocrine Tissues Thyroid Moderate to strong Trop-2 staining of apical membranes in a variable number of follicles. Parathyroid Negative. Adrenal gland Negative. Pituitary gland Moderate Trop-2 staining of a small fraction of epithelial cells of the adenohypophysis. Respiratory system Respiratory epithelium Strong Trop-2 staining of all cells of the respiratory epithelium. Moderate Trop-2 staining of bronchial glands. Lung Moderate Trop-2 staining of all pneumocytes. Gastrointestinal Tract Salivary glands Strong Trop-2 staining of all epithelial cells. Esophagus Strong Trop-2 staining of all squamous epithelial cells, with the exception of basal cells which are negative or only weakly positive. Stomach Moderate Trop-2 staining of superficial epithelial cell layers. Duodenum Few scattered Trop-2 positive epithelial cells. Small ... A positive Trop-2 immunostaining of variable intensity can be seen in a broad range of different tumor entities which are mostly derived from Trop-2 positive normal cell types. The TCGA findings on TACSTD2 RNA expression in different tumor categories have been summarized in the Human Protein Atlas. Esophageal adenocarcinoma with strong Trop-2 immunostaining of tumor cells Squamous cell carcinoma of the oral cavity showing a strong, predominantly membranous Trop-2 positivity of tumor cells Papillary thyroid cancer with strong Trop-2 positivity of tumor cells Cancer tissue gallery TROP2 (MSVA-733R) publication summary Relevant publication: Dum et al.: “Trophoblast cell surface antigen 2 (TROP2) expression in human tumors: A tissue microarray study on 18,563 tumors.” Published in Pathobiology. 2022 Apr 27:1-14. PMID: 35477165. A total of 16,024  tumors from 150 different tumor categories were successfully analyzed for TROP2 by using the following protocol:  Heat-induced antigen retrieval for 5 minutes in an autoclave at 121°C in pH 7,8 Target Retrieval Solution buffer. MSVA-733R at a dilution of 1:150 at 37°C for 60 minutes. Visualization of bound antibody by the EnVision Kit (Dako, Agilent). This protocol was also used for all TROP2 immunostainings depicted in our tumor and normal tissue galleries. At least one case with a positive TROP2 immunostaining was seen in 109 (72.6%) and at least one case with a strong TROP2 immunostaining was seen in 89 (59.3%) of 150 tumor categories. The distribution of positive staining results is shown in an “organ-systematic” (Fig... IHC users have different preferences on how the stains should look like. Some prefer high staining intensity of the target stain and even accept some background. Others favor absolute specificity and lighter target stains. Factors that invariably lead to more intense staining include higher concentration of the antibody and visualization tools, longer incubation time, higher temperature during incubation, higher temperature and longer duration of the heat induced epitope retrieval (slide pretreatment). The impact of the pH during slide pretreatment has variable effects and depends on the antibody and the target protein. All images and data shown here and in our image galleries are obtained by the manual protocol described below. Other protocols resulting in equivalent staining are described as well. Manual protocol Freshly cut sections should be used (less than 10 days between cutting and staining). Heat-induced antigen retrieval for 5 minutes in an autoclave at 121°C in pH 7,8 Target ... The predictive and prognostic role of Trop-2 expression in cancer requires further evaluation. It is currently unclear whether the extent of Trop-2 expression in tumor cells predicts a response to anti-Top-2 drugs. The prevalence of Trop-2 overexpression is unclear for many tumor entities. There are only two methods for documentation of antibody specificity for immunohistochemistry on formalin fixed tissues. These are: 1. comparison with a second independent method for target expression measurement across a large number of different tissue types (orthogonal strategy), and 2. Comparison with one or several independent antibodies for the same target and showing that all positive staining results are also seen with other antibodies for the same target (independent antibody strategy). Both of these methods were applied for validation of MSVA-733R . Orthogonal validation: For this validation method, RNA expression data from public datasets which all summarized in the Human Protein Atlas (Tissue expression TACSTD2) were used. These RNA data describe Trop-2 expression in all organs containing squamous epithelium as well as several other organs as Trop-2 positive. Immunostaining by using MSVA-733R was detected in the organs with documented Trop-2 RNA expression but also a series...