295,00 995,00 

Delivery Time: In Stock

Clear

Product details

Synonyms = BCH, Benign chorea, BHC, Homeobox protein Nkx2.1, NK2 homeobox 1, NKX2.1, NKX2A, TEBP, Thyroid nuclear factor-1, Thyroid specific enhancer binding protein, Thyroid transcription factor-1 (TTF-1), Tin man, TITF1, TTF-1

Antibody type = Recombinant Rabbit monoclonal / IgG

Clone = MSVA-312R

Positive controlLung: Nuclear TTF1 staining should be strong in pneumocytes and in basal cells of the terminal bronchioles while a weaker, still moderate to strong staining should be seen in columnar epithelial cells of the terminal bronchioles (low expressor control).

Negative controlLiver: TTF1 staining must not be seen in any cells.

Cellular localization = Nucleus

Reactivity = Human

 

 

Application = Immunohistochemistry
Dilution = 1:100 – 1:200
Intended Use = Research Use Only

Relevance of Antibody

TTF-1 is a protein with high specificity for lung and thyroid.

Biology Behind

Thyroid transcription factor-1 (TTF1), also termed NK2 homeobox 1 (NKX2-1) is a 38 kDa nuclear protein encoded by the NKX2-1 gene at chromosome 14q13. TTF1 has a critical role in morphogenesis of the thyroid, the lung and the diencephalon where it acts as a tissue-specific transcription promoter. Blocking TTF1 gene expression results in developmental defects of thyroid, lung and brain. In the thyroid gland, TTF1 induces the expression of thyroglobulin, thyroperoxidase and thyrotropin receptor. In the lung, TTF1 promotes the transcription of the surfactant proteins A to D, and the Clara cell secretory protein. Among normal tissues, TTF1 expression is restricted to the respiratory system, thyroid, pituitary gland, and the thalamus. Among cancers, TTF1 expression is particularly common in thyroid cancer, pulmonary adenocarcinoma, pulmonary small cell carcinomas, as well as in small cell carcinomas from other sites of origin. Less commonly, TTF1 positivity is also seen in other tumor entities including colorectal, endometrial and stomach cancers.

Staining Pattern in Normal Tissues

Images describing the TTF1 staining pattern in normal tissues obtained by the antibody MSVA-312R are shown in our “Normal Tissue Gallery”.

 

Brain Cerebrum Negative.
Cerebellum Negative.
Endocrine Tissues Thyroid StrongTTF1 staining of all follicular epithelial cells.
Parathyroid Negative.
Adrenal gland Negative.
Pituitary gland StrongTTF1 staining of pituicytes.
Respiratory system Respiratory epithelium Strong TTF1 staining of respiratory epithelial cells, especially of basal cells in bronchial mucosa. TTF1 staining is much weaker or absent in respiratory epithelial cells of paranasal sinus. Weak to moderate TTF1 positivity of mucinous cells in bronchial glands.
Lung Strong TTF1 staining of pneumocytes.
Gastrointestinal Tract Salivary glands Negative.
Esophagus Negative.
Stomach Negative.
Duodenum Negative.
Small intestine Negative.
Appendix Negative.
Colon Negative.
Rectum Negative.
Liver Negative.
Gallbladder Negative.
Pancreas Negative.
Genitourinary Kidney Negative.
Urothelium Negative.
Male genital Prostate Negative.
Seminal vesicles Negative.
Testis Negative.
Epididymis Negative.
Female genital Breast Negative.
Uterus, myometrium Negative.
Uterus, ectocervix Negative.
Uterus endocervix Negative.
Uterus, endometrium Negative.
Fallopian Tube Negative.
Ovary Negative.
Placenta early Negative.
Placenta mature Negative.
Amnion Negative.
Chorion Negative.
Skin Epidermis Negative.
Sebaceous glands Negative.
Muscle/connective tissue Heart muscle Negative.
Skeletal muscle Negative.
Smooth muscle Negative.
Vessel walls Negative.
Fat Negative.
Stroma Negative.
Endothelium Negative.
Bone marrow/lymphoid tissue Bone marrow Negative.
Lymph node Negative.
Spleen Negative.
Thymus Negative.
Tonsil Negative.
Remarks TTF1 staining is always nuclear.

 

These findings are largely consistent with the RNA data described in the Human Protein Atlas (Tissue expression TTF-1)  All organs with documented TTF1 RNA expression (respiratory system, thyroid, pituitary gland) are IHC positive for MSVA-312R. Moreover, immunostaining by MSVA-312R is also limited to these organs.

 

 

Positive controlLung: Nuclear TTF1 staining should be strong in pneumocytes and in basal cells of the terminal bronchioles while a weaker, still moderate to strong staining should be seen in columnar epithelial cells of the terminal bronchioles (low expressor control).

Negative controlLiver: TTF1 staining must not be seen in any cells.

 

Normal tissue gallery

Staining Pattern in Relevant Tumor Types

Among thyroid cancers, TTF1 is seen in virtually all tumors derived from follicular cells (i.e. follicular adenoma, follicular and papillary carcinoma). C-cell derived medullary carcinomas are mostly TTF1 positive while anaplastic thyroid carcinomas are usually negative. Among lung cancers, adenocarcinomas are positive in 60-85% but mucinous adenocarcinomas are more often negative. Small cell carcinomas of the lung are TTF1 positive in >90% of cases but extrapulmonary small cell carcinomas are also often positive (>40%). TTF1 positivity is (rarely) also seen in other tumor entities including colorectal, endometrial and stomach cancers.

 

The TCGA findings on TTF-1 RNA expression in different tumor categories have been summarized in the Human Protein Atlas.

 

 

Cancer tissue gallery

Compatibility of Antibodies

No data available at the moment

Protocol Recommendations

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 Retrieval Solution buffer. Apply MSVA-312R at a dilution of 1:150 at 37°C for 60 minutes. Visualization of bound antibody by the EnVision Kit (Dako, Agilent) according to the manufacturer’s directions.

Potential Research Applications

  • Distinction of lung adenocarcinoma (usually positive) from metastasis to the lung (usually negative) and pleural mesothelioma (negative).
  • Distinction of Merkel cell carcinoma (usually negative) from metastatic small cell carcinoma of the lung (mostly positive)

Evidence for Antibody Specificity in IHC

There are two ways how the specificity of antibodies can be documented 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). 

 

Orthogonal validation: For the antibody MSVA-312R specificity is suggested by the complete concordance of the immunostaining data with data from three independent RNA screening studies, including the Human Protein Atlas (HPA) RNA-seq tissue dataset, the FANTOM5 project, and the Genotype-Tissue Expression (GTEx) project, which are all summarized in the Human Protein Atlas (Tissue expression TTF-1). TTF1 immunostaining by MSVA-312R was only seen in the three tissues, for which RNA expression had been described (respiratory system, thyroid, pituitary gland). 

 

Comparison of antibodies: True TTF1 staining by MSVA-312R was also corroborated by a staining of all cell types detected by MSVA-312R by a commercially available independent second antibody (termed “validation antibody”). 

 

Independence of the two antibodies used for validation is documented by a multitude of non-specific/cross-reactive stainings that were seen for the validation antibody but not for MSVA-312R. These for example included staining of the brain, intense cytoplasmic staining of the liver as well as less intense cytoplasmic stainings of several other structures such as tubuli of the kidney. 

 

 

Normal tissue gallery