Testican

Last updated

Testican is a type of proteoglycan. Testican-1 is a highly conserved, multidomain proteoglycan that is most prominently expressed in the thalamus, and is upregulated in activated astroglial cells of the cerebrum. Several functions of this gene product have now been demonstrated in vitro including membrane-type matrix metalloproteinase inhibition, cathepsin L inhibition, and low-affinity calcium binding. The purified gene product has been shown to inhibit cell attachment and neurite extensions in culture. Functions of testican in vivo have yet to be demonstrated in knockout mice or other models. Testican has been shown to carry substantial amounts of chondroitin sulfate as well as other oligosaccharides, but the biological significance of these embellishments is not yet known.

In humans there are three testicans:

Testican-1 plays a role in lapatinib resistance, which is a drug used to treat HER2-positive gastric cancer. [1] When testican-1 levels are artifically reduced, sensitivity towards lapatinib was once again increased. [1] This shows the potential for future use in combatting drug resistance.

  1. 1 2 Kim, H.-P.; Han, S.-W.; Song, S.-H.; Jeong, E.-G.; Lee, M.-Y.; Hwang, D.; Im, S.-A.; Bang, Y.-J.; Kim, T.-Y. (2014). "Testican-1-mediated epithelial–mesenchymal transition signaling confers acquired resistance to lapatinib in HER2-positive gastric cancer". Oncogene. 33 (25): 3334–3341. doi: 10.1038/onc.2013.285 . ISSN   1476-5594. PMID   23873022.

Related Research Articles

Autocrine signaling is a form of cell signaling in which a cell secretes a hormone or chemical messenger that binds to autocrine receptors on that same cell, leading to changes in the cell. This can be contrasted with paracrine signaling, intracrine signaling, or classical endocrine signaling.

<span class="mw-page-title-main">Trastuzumab</span> Pharmaceutical drug

Trastuzumab, sold under the brand name Herceptin among others, is a monoclonal antibody used to treat breast cancer and stomach cancer. It is specifically used for cancer that is HER2 receptor positive. It may be used by itself or together with other chemotherapy medication. Trastuzumab is given by slow injection into a vein and injection just under the skin.

An angiogenesis inhibitor is a substance that inhibits the growth of new blood vessels (angiogenesis). Some angiogenesis inhibitors are endogenous and a normal part of the body's control and others are obtained exogenously through pharmaceutical drugs or diet.

Quinazoline is an organic compound with the formula C8H6N2. It is an aromatic heterocycle with a bicyclic structure consisting of two fused six-membered aromatic rings, a benzene ring and a pyrimidine ring. It is a light yellow crystalline solid that is soluble in water. Also known as 1,3-diazanaphthalene, quinazoline received its name from being an aza derivative of quinoline. Though the parent quinazoline molecule is rarely mentioned by itself in technical literature, substituted derivatives have been synthesized for medicinal purposes such as antimalarial and anticancer agents. Quinazoline is a planar molecule. It is isomeric with the other diazanaphthalenes of the benzodiazine subgroup: cinnoline, quinoxaline, and phthalazine. Over 200 biologically active quinazoline and quinoline alkaloids are identified.

<span class="mw-page-title-main">HER2</span> Mammalian protein found in humans

Receptor tyrosine-protein kinase erbB-2 is a protein that in humans is encoded by the ERBB2 gene. ERBB is abbreviated from erythroblastic oncogene B, a gene originally isolated from the avian genome. The human protein is also frequently referred to as HER2 or CD340.

<span class="mw-page-title-main">Lapatinib</span> Cancer medication

Lapatinib (INN), used in the form of lapatinib ditosylate (USAN) is an orally active drug for breast cancer and other solid tumours. It is a dual tyrosine kinase inhibitor which interrupts the HER2/neu and epidermal growth factor receptor (EGFR) pathways. It is used in combination therapy for HER2-positive breast cancer. It is used for the treatment of patients with advanced or metastatic breast cancer whose tumors overexpress HER2 (ErbB2).

<span class="mw-page-title-main">Pertuzumab</span> Pharmaceutical drug

Pertuzumab, sold under the brand name Perjeta, is a monoclonal antibody used in combination with trastuzumab and docetaxel for the treatment of metastatic HER2-positive breast cancer; it also used in the same combination as a neoadjuvant in early HER2-positive breast cancer.

CDK7 is a cyclin-dependent kinase shown to be not easily classified. CDK7 is both a CDK-activating kinase (CAK) and a component of the general transcription factor TFIIH.

<span class="mw-page-title-main">Cyclin-dependent kinase 7</span> Protein-coding gene in the species Homo sapiens

Cyclin-dependent kinase 7, or cell division protein kinase 7, is an enzyme that in humans is encoded by the CDK7 gene.

<span class="mw-page-title-main">Afatinib</span> Chemical compound

Afatinib, sold under the brand name Gilotrif among others, is a medication which is used to treat non-small cell lung carcinoma (NSCLC). It belongs to the tyrosine kinase inhibitor family of medications. It is taken by mouth.

<span class="mw-page-title-main">Neratinib</span> Chemical compound

Neratinib (INN), sold under the brand name Nerlynx, is a tyrosine kinase inhibitor anti-cancer medication used for the treatment of breast cancer.

<span class="mw-page-title-main">Tyrosine kinase inhibitor</span> Drug typically used in cancer treatment

A tyrosine kinase inhibitor (TKI) is a pharmaceutical drug that inhibits tyrosine kinases. Tyrosine kinases are enzymes responsible for the activation of many proteins by signal transduction cascades. The proteins are activated by adding a phosphate group to the protein (phosphorylation), a step that TKIs inhibit. TKIs are typically used as anticancer drugs. For example, they have substantially improved outcomes in chronic myelogenous leukemia. They have also been used to treat other diseases, such as idiopathic pulmonary fibrosis.

<span class="mw-page-title-main">ALK inhibitor</span>

ALK inhibitors are anti-cancer drugs that act on tumours with variations of anaplastic lymphoma kinase (ALK) such as an EML4-ALK translocation. They fall under the category of tyrosine kinase inhibitors, which work by inhibiting proteins involved in the abnormal growth of tumour cells. All the current approved ALK inhibitors function by binding to the ATP pocket of the abnormal ALK protein, blocking its access to energy and deactivating it. A majority of ALK-rearranged NSCLC harbour the EML4-ALK fusion, although as of 2020, over 92 fusion partners have been discovered in ALK+ NSCLC. For each fusion partner, there can be several fusion variants depending on the position the two genes were fused at, and this may have implications on the response of the tumour and prognosis of the patient.

<span class="mw-page-title-main">Trastuzumab emtansine</span> Pharmaceutical drug

Trastuzumab emtansine, sold under the brand name Kadcyla, is an antibody-drug conjugate consisting of the humanized monoclonal antibody trastuzumab (Herceptin) covalently linked to the cytotoxic agent DM1. Trastuzumab alone stops growth of cancer cells by binding to the HER2 receptor, whereas trastuzumab emtansine undergoes receptor-mediated internalization into cells, is catabolized in lysosomes where DM1-containing catabolites are released and subsequently bind tubulin to cause mitotic arrest and cell death. Trastuzumab binding to HER2 prevents homodimerization or heterodimerization (HER2/HER3) of the receptor, ultimately inhibiting the activation of MAPK and PI3K/AKT cellular signalling pathways. Because the monoclonal antibody targets HER2, and HER2 is only over-expressed in cancer cells, the conjugate delivers the cytotoxic agent DM1 specifically to tumor cells. The conjugate is abbreviated T-DM1.

<span class="mw-page-title-main">Palbociclib</span> Medication for HR+ HER2− breast cancer

Palbociclib, sold under the brand name Ibrance among others, is a medication developed by Pfizer for the treatment of HR-positive and HER2-negative breast cancer. It is a selective inhibitor of the cyclin-dependent kinases CDK4 and CDK6. Palbociclib was the first CDK4/6 inhibitor to be approved as a cancer therapy.

<span class="mw-page-title-main">Copanlisib</span> Chemical compound

Copanlisib, sold under the brand name Aliqopa, is a medication used for the treatment of adults experiencing relapsed follicular lymphoma who have received at least two prior systemic therapies.

<span class="mw-page-title-main">Ribociclib</span> Chemical compound

Ribociclib, sold under the brand name Kisqali, is a medication used for the treatment of certain kinds of breast cancer. Ribociclib is a kinase inhibitor. It was developed by Novartis and Astex Pharmaceuticals.

mIR489 Non-coding RNA in the species Homo sapiens

MicroRNA 489 is a miRNA that in humans is encoded by the MIR489 gene.

<span class="mw-page-title-main">Trastuzumab deruxtecan</span> Medication

Trastuzumab deruxtecan, sold under the brand name Enhertu, is an antibody-drug conjugate consisting of the humanized monoclonal antibody trastuzumab (Herceptin) covalently linked to the topoisomerase I inhibitor deruxtecan. It is licensed for the treatment of breast cancer or gastric or gastroesophageal adenocarcinoma. Trastuzumab binds to and blocks signaling through epidermal growth factor receptor 2 (HER2/neu) on cancers that rely on it for growth. Additionally, once bound to HER2 receptors, the antibody is internalized by the cell, carrying the bound deruxtecan along with it, where it interferes with the cell's ability to make DNA structural changes and replicate its DNA during cell division, leading to DNA damage when the cell attempts to replicate itself, destroying the cell.

Endocrine therapy is a common treatment for estrogen receptor positive breast cancer. However, resistance to this therapy can develop, leading to relapse and progression of disease. This highlights the need for new strategies to combat this resistance.