An overview of several commonly used epithelial tissue and tumor markers (section one)

1. Keratin

Keratin is divided into two types, epidermal keratin and cytokeratin, depending on the location of its fraction. Epidermal keratin includes skin epidermis, gastrointestinal mucosa epithelium, glandular epithelium thyroid follicular epithelium, trachea, bronchial epithelium, alveolar epithelium, corneal epithelium, prostate epithelium etc. Cytokeratins include submandibular glands, pancreas, thymus, cells, hepatocytes, and tubular cells. Currently, antibodies prepared by using the above-mentioned cell intermediate filament keratin as an antigen include monoclonal antibodies and polyclonal antibodies.

Keratins have 19 subtypes, either alkaline or acidic; 1-8 is alkaline, and 9-19 is acidic. Their molecular weights range from 40 to 68. The stratified squamous epithelium is mostly high molecular weight, and the single layer epithelium is mostly low molecular weight, understanding these are extremely helpful in the clinical differential diagnosis and application of antibodies.

At present, there are many antibodies that detect such traits, and antibodies of different types are produced according to different clones. Commonly used antibodies are:

(1). Monoclonal mouse anti human cytokeratin, clone MNF116.

The range of applications for this antibody is wide, including various types of frozen sections, smears, cell culture pieces and tissue sections embedded in paraffin fixed with formaldehyde. The positive tissues detected by the antibody are: squamous epithelium, thyroid follicular epithelial gastrointestinal epithelium, pancreatic bile duct epithelium, hepatobiliary epithelium, corneal epithelium etc., and tumors of the above origin. It should be noted that there are some tumors show positive expression in both directions, such as CK and Vimentin: intratumoral tumor, endometrial adenocarcinoma adenocarcinoma, epithelioid tumor, synovial tumor, salivary gland myoepithelial neoplasia, mesothelioma and so on. This is due to the presence of two different intermediate filaments in these tumors.

Tumors that are negative by this antibody are: lymphomas, various types of myogenic tumors, malignant melanoma, bone tumors, fibrous tissue tumors, fat tumors, nerve tissue tumors, and seminoma.

In the detection of certain tumors, such problems often occur: on the same slice, the same squamous cell carcinoma cells, some antigens are strongly positive, some are moderately positive, and some are expressed as weakly positive, and some even negative. This is mainly because various cells are in different stages of hyperplasia, and the amount of antigen secreted by the cells is different, and thus the expression is also different.

This antibody can be detected by various methods, but it is preferred to use the vacuum negative pressure LSAB method.

(2). Monoclonal mouse anti-human cytokeratin, clone LP34.

The range of use and detection of tissues of this antibody is basically the same as in (1), but the effect is not as good as (1).

(3). Monoclonal mouse anti-human cytokeratin, clone 35BH11.

This antibody is characterized by: A. It can detect almost all non-squamous epithelia, including ovarian adenocarcinoma, gastrointestinal adenocarcinoma, thyroid cancer, liver cancer, uterine cancer, kidney cancer and son on. B. It does not react with the squamous epithelium. C. It is positive for bladder cancer, nasopharyngeal carcinoma, and thymic cancer. However, this antibody can only be used for frozen sections, smears and cell culture plates. It cannot be used for paraffin sectioning.

(4). Monoclonal mouse anti-human cytokeratin, clone 34BE12. This antibody is of a high molecular weight type that detects tissues of squamous epithelial and stratified epithelium and tumors from which they originate.

Application scope: it can be used for various types of slicing.