Anaplastic lymphoma kinase

Anaplastic lymphoma kinase (ALL) is a protein that encodes a gene of the same name. Thus the term can refer to one or the other. As a protein it is found on the surface of cells, where it acts as a signal receptor (a receptor tyrosine kinase), meaning that it is an important regulator of many processes occurring within the cell.

[UPDATE: "anaplastic lymphoma kinase" is technically no longer in use as the name of the gene; it has been replaced by "anaplastic lymphoma receptor tyrosine kinase".]

While the ALK gene plays an important part in the life of the healthy cell, the gene has been implicated as an oncogene—cancer-causing—when it has been found to be amplified, rearranged, or mutated. Anaplastic lymphoma kinase is also one of the few tyrosine kinases that has been shown to have a role in the pathogenesis (medical terminology meaning the development of a disease) of some lymphomas.

Anaplastic lymphoma kinase in ALCL

Typically, cells express the ALK protein on their surfaces only in cells that are part of the development and maturity of the brain and central nervous system. Normal lymphoid cells, in persons of any age, do not express ALK.

The same is not true for some abnormal lymphoid cells. In fact, ALK expression can be found in over 60 percent of cases of the non-Hodgkin's lymphoma T-cell subtype anaplastic large cell lymphoma (ALCL), an extremely uncommon lymphoma, amounting to about 3 percent of all adult lymphomas. ALCL ALK+ (ALK positive) means that the disease is expressing the ALK protein on the surface of its cells. ALCL ALK- (ALK negative) means that the disease is not expressing the ALK protein. Whereas these two non-Hodgkin's lymphoma subtypes used to be considered two versions of the same disease, recent studies have shown that in fact they are fully separate disease entities with different treatment approaches and differing prognoses.

In fact, the prognosis differs drastically; ALK+ disease enjoys a very good prognosis when treated with CHOP chemotherapy—as many as 80 percent of all patients can look forward to a successful treatment course and a very long disease-free survival. On the other hand, as many as 70 percent of patients with ALK- disease are expected to relapse within five years of treatment.

Anaplastic lymphoma kinase in other cancers

The ALK is not only implicated in anaplastic large cell lymphoma. Recently it has been found to be responsible for a small percentage of neuroblastomas, a childhood form of brain cancer, an even smaller percentage of non small cell lung cancers, and some inflammatory myofibroblastic tumors.

Sources

More Articles

More Articles

This article looks at the Non-Hodgkin's Lymphoma survival rate as well as the Non-Hodgkin's Lymphoma mortality rate ....

The term NK T cell lymphoma refers to one of two subtypes of lymphoma that affect the NK (Natural Killer)...

Canine lymphoma is a fairly common cancer in American dogs. The most commonly seen lymphoma in America is a type called Lymphosarcoma, although...

Prednisone is a glucocorticosteroid (a steroid) used in the treatment of many types of cancers. It functions as an anti-inflammatory medicine that...

Marginal zone lymphomas (MZL) are indolent lymphomas that affect the B-cells. The...

Large Cell Lymphoma (LCL) is typically an aggressive (fast growing) cancer of either the B cell or T cell type. They are one of the most common...

A B cell is a type of lymphocyte that produces antibodies to fight infections. These are the most prevalent lymphocytes in the bloodstream and are...

Aggressive Non-Hodgkin’s Lymphomas (NHLs) are fast growing cancers (as opposed to indolent cancers). They involve...

A lymphoma prognosis varies greatly depending on the type of lymphoma. There are more than 35 types of lymphoma, including 5 types of...

What causes lymphoma is not well known. DNA mutations may be what causes lymphoma to develop but what triggers these mutations is...

Often the one who makes the first diagnosis of Hodgkin's Lymphoma / Disease is the person affected. There are some...

Lymphedema is abnormal swelling due to the presence of excess lymphatic fluid within the tissues. This swelling occurs when the...

RICE is an acronym for an anti-cancer treatment that expresses a combination chemotherapeutic regimen. This regimen is written variously as "R+ICE...

Hodgkin's Disease—also referred to as Hodgkin's Lymphoma, these are the exact same diseases, just...

Lymphoma is a cancer affecting the white blood cells (lymphocytes) of the body's immune system. The cells begin to grow abnormally and much faster...