What is immunohistochemistry for p16?

What is immunohistochemistry for p16?

p16INK4a immunohistochemistry (IHC) is widely used to facilitate the diagnosis of human papillomavirus (HPV)-associated cervical precancerous lesions. Although most p16 results are distinctly positive or negative, certain ones are ambiguous: they meet some but not all requirements for the “block-positive” pattern.

What is p16 antibody?

Product Description. p16 antibody: p16 INK4a is a tumor suppressor protein involved in the pathogenesis of a variety of malignancies. It is a specific inhibitor of cdk4/cdk6. Recent analyses of the p16INK4a gene revealed homozygous deletions, nonsense, missense, or frameshift mutations in several human cancers (1).

What is p16 immunohistochemical stain?

P16INK4a immunohistochemistry (IHC) is widely used to facilitate the diagnosis of human papillomavirus (HPV)-associated cervical precancerous lesions. While most p16 results are distinctly positive or negative, certain ones are ambiguous: they meet some but not all requirements for the “block-positive” pattern.

What is block positivity?

Positive staining is defined as “block” staining: strong nuclear and cytoplasmic expression in a continuous segment of cells (at least 10 – 20 cells); in squamous epithelium, block positivity needs to involve basal and parabasal layers.

What does p16 equivocal mean?

Discussion. Our results suggest that the pattern of p16 immunohistochemical staining in HNSCC can reliably predict HPV status in cases deemed as “equivocal” because they do not fall into the positive/negative dichotomy according to a numerical percentage cutoff used in many studies [17–22].

What is p16 expression?

p16 is a cyclin-dependent kinase-4 inhibitor that is expressed in a limited range of normal tissues and tumors. In recent years, immunohistochemistry with p16 antibodies has been used as a diagnostic aid in various scenarios in gynecologic pathology.

What is p16 cervix?

Diffuse (as opposed to focal) positivity with p16 in the cervix can be regarded as a surrogate marker of the presence of high-risk human papillomavirus (HPV).

What is p16 in a cervical biopsy?

The p16INK4A gene was found inactivated in a large percentage of tumor cell lines, suggesting that it was indeed a tumor suppressor gene [11–13]. p16INK4A overexpression has been demonstrated in cervical cancers as a result of functional inactivation of RB by the HPV E7 protein [14].

What is p16 antibody used for?

p16 Antibody (about p16 [BC42] Clone BC42) p16 antibody is a mouse IgG1 monoclonal antibody from Biocare Medical designed for the qualitative identification of p16 INK4a protein by immunohistochemistry (IHC) in formalin-fixed paraffin-embedded (FFPE) human tissues for in-vitro diagnostic (IVD) use.

What does a positive p16 INK4a mean?

p16 antibody is the primary antibody commonly used to detect the expression of p16 INK4a by IHC. Positive immunostaining manifests as a strong and diffuse block positive pattern of staining while negative or non–block-positive staining indicates low-grade disease or a non–Human Papilloma Virus (HPV)-associated pathology.

What is the immunohistochemical identification of p16 in cervical dysplasia?

The immunohistochemical identification of p16 is particularly relevant in uterine cervical lesions: Development of dysplasia is closely related to human papilloma virus (HPV) infection. Two viral oncogenes, E6 and E7, both interact with various cell cycle-regulating proteins.

How does the p16 gene affect cell senescence?

Increased expression of the p16 gene, which is seen as organisms age, reduces the proliferation of stem cells. This reduction in the division and production of stem cells protects against cancer while increasing the risks associated with cellular senescence.