Tumor Markers

We offer a wide range of key antibodies and antigens for Tumor Markers related research and diseases, including AFP, CA 125, CA 15-3 , CA 19-9, CA 72-4 , CA242, CEA, CYFRA21-1, HE4, Hemoglobin, NSE, Pepsinogen I, Pepsinogen II, PSA, SCCA and IGFBP4.

Alpha-fetoprotein (AFP), a 70kDa glycoprotein with a single polypeptide chain, is synthesized by the liver, yolk sac, and GI tract of the fetus. The protein is abundantly present in the fetus, and levels decline rapidly after birth. AFP levels are known to be elevated in a number of benign diseases and conditions including pregnancy and nonmalignant liver diseases such as hepatitis and cirrhosis. It is also used as a biomarker to detect certain tumors. Although limited screening studies have been conducted with promising results, AFP is neither recommended as a screening test or as a diagnostic test.

Cancer antigen 125 (CA 125) is now known as MUC16 as it is encoded for by the MUC16 gene. The CA 125 antigen is expressed in copious amounts in the tissues and serum of epithelial ovarian carcinoma patients. This antigen is minimally present in normal serum, or in adult or fetal ovaries. CA 125 is the most important cancer-associated marker for the management of ovarian cancer. It is also used for the differential diagnosis of pelvic masses.

Cancer antigen 15-3 (CA 15-3), a protein produced by normal breast cells, is a large mucinous glycoprotein with a native molecular mass in excess of 400kDa. The CA 15-3 antigen is an epithelial membrane antigen expressed on normal cells and found in serum. Since CA 15-3 can be measured in the blood, it is useful as a tumor marker to follow the course of the cancer. In many people with cancerous breast tumors, there is an increased production of CA 15-3 and the related cancer antigen 27.29. Elevated levels of this antigen are found in about 60% of preoperative breast cancer and 80% of advanced metastatic breast cancer.

Carbohydrate antigen 19-9 (CA19-9) is a specific carbohydrate epitope called sialylated Lewis-a pentasaccharide, also known as sLea antigen. This epitope is found on several glycoproteins, including Mucin-1. In healthy individuals, the serum concentration of CA19-9 is low, but it increases during gastrointestinal malignancies, including pancreatic cancer, pancreatic or hepatobiliary adenocarcinoma, or colon cancer. Thus, CA19-9 can be used as a tumor marker predominantly associated with pancreatic, gall bladder, gastric, and colorectal cancers, which are collectively classifed as GI malignancies.

Cancer antigen 72-4 (CA 72-4) was identified as a 1 MDa mucine-like Glycoprotein complex termed TAG-72 (tumor associated antigen 72). TAG 72 is a mucin-like protein of high molecular weight (200- 400 kD). There is a good correlation between CA 72-4 levels and tumor stage and size. Elevated CA 72-4 levels in serum and plasma have been reported in various malignant diseases including carcinomas of pancreas, stomach, gall, colon, mamma, ovaries, cervix and endometrium. CA 72-4 is a tumor marker primarily associated with gastric and ovarian cancer, it is also associated with esophageal cancer, pancreatic carcinoma and other tumors. It has been used as an independent marker for the therapeutic monitoring and follow-up care of ovarian cancer patients, in particular in CA 125 negative patients.

CA242 is found on the same mucin-complex as CA50 and sialylated Lewisa (CA19-9). Thus, CA242 is related, but not identical to the epitope of CA19-9. Serum levels of CA242 are low in healthy subjects and subjects with benign diseases, while elevated levels are commonly found in serum from patients with gastro-intestinal cancer. The CA242 marker may be used as an aid in the diagnosis and management of patients with known or suspected gastro-intestinal carcinomas.

Carcinoembryonic antigen (CEA) is a complex immunoreactive glycoprotein involved in cell adhesion with a molecular weight of 180,000 comprising 60% carbohydrate. CEA is normally produced during fetal development, but the production of CEA stops before birth. Therefore, it is not usually present in the blood of healthy adults, but elevated levels have been found in individuals with carcinomas. CEA measurement is mainly used as a tumor marker to identify recurrences after surgical resection. CEA levels may also be raised in some non-neoplastic conditions like ulcerative colitis, pancreatitis, and cirrhosis.

CYFRA21-1 is a fragment of cytokeratin 19 which is expressed in various types of epithelial cells and tumor cells of epithelial origin. CYFRA 21-1 is elevated in most lung tumors of the non-small cell category, with the highest sensitivity in lung squamous cell cancers.

Human epididymis protein 4 (HE4), also known as WAP four-disulfide core domain protein 2, is a 124 amino acid long protease inhibitor. HE4 suggest a higher specifcity than CA 125 in different benign and malignant conditions, excluding renal failure. Serum HE4 is often measured together with CA125 to monitor progression of epithelial ovarian cancer after treatment.

Hemoglobin is the iron-containing metalloprotein in red blood cells. It transports oxygen from the lungs to the body tissues. Deviations from normal values usually indicate abnormalities, such as anemia.

Neuron Specific Enolase (NSE), also known as enolase 2 (ENO2), is an enzyme that is encoded by the ENO2 gene. Measurement of NSE in serum can assist in the differential diagnosis of a variety of neuron-destructive and neurodegenerative disorders. NSE is also frequently over-expressed by neural crest-derived tumors. Falling or rising levels are often correlated with tumor shrinkage or recurrence, respectively. NSE is therefore a useful tumor marker for lung cancer patients.

Pepsinogen I (PGI) and Pepsinogen II (PGII): Serum pepsinogen estimation is a useful diagnostic tool in the diagnosis of carcinoma stomach.

The pepsinogens are gastric acid protease zymogens. They are divided into two distinct immunochemical groups: Pepsinogen I and II. The major part of pepsinogen is secreted into the gastric lumen but a small amount can be found in the blood. Alterations in the serum pepsinogen concentrations has been found with Helicobacter pylori (H. Pylori) infections, peptic ulcer disease, gastritis, and gastric cancer. Low level of serum pepsinogen I (PGI) and/or the ratio of PGI to PGII is an accurate indicator of chronic atrophic gastritis, which is a very important precursor of gastric cancer.

Prostate-specific antigen (PSA), also known as kallikrein-3, is a glycoprotein enzyme encoded in humans by the KLK3 gene. PSA is a member of the kallikreinrelated peptidase family and is secreted by the epithelial cells of the prostate gland.

PSA is present in small quantities in the serum of healthy men, and is often elevated in the presence of prostate cancer and in other prostate disorders. A blood test to measure PSA is considered the most effective test currently available for the early detection of prostate cancer, but this effectiveness has also been questioned.

Squamous cell carcinoma antigen (SCCA) is a 48kDa glycoprotein, originally isolated from a squamous cancer of the uterine cervix and belong to the family of serine/cysteine -protease inhibitors. SCC antigen is a serological marker of squamous cell carcinomas of the uterine cervix, vulva, lung, head, neck, and oesophagus. In squamous cell carcinoma of the uterine cervix, pre-treatment serum SCC antigen may be used as an early stage prognostic factor. Further, for patients with elevated levels of SCC antigen before start of treatment, the profile of SCC antigen correlates with the response to radio- and chemo-therapy and measurement of SCC antigen may thus be used to monitor the effect of therapy and for early detection of recurrent disease.

Insulin-like growth factor-binding protein 4 (IGFBP-4) is a protein expressed in a variety of tissues and cells such as embryonic and postnatal brain, human osteoblast-like cells, skin fibroblasts, endothelial cells, epithelial cells, intestinal epithelium, and in a variety of tumor cells. IGFBP-4 is a unique protein and it consistently inhibits several cancer cells in vivo and in vitro. Its inhibitory action which has been shown in vivo in prostate and colon is regulated by proteolysis through Pregnancy-associated plasma protein-A (PAPP-A). PAPP-A has been proposed to be a marker of unstable plaques and therefore increased concentrations of IGFBP-4- fragments in blood circulation could serve as a read out of increased PAPP-A activity in plaques.