B-cell Cancer and Different Stages of B-lymphocyte Development - Essay Example

At any point in the body, millions of B cells are circulating in the blood and lymph (the fluid and protein that has been squeezed out of the blood i.e. blood plasma) but are not producing antibodies. Once the B cell encounters its corresponding antigen and receives an additional signal from a helper T cell, it can further make a distinction into two types; plasma b-cells and memory b-cells. "In humans, the development of B cells in the bone marrow is initiated by the assembly of genes for the variable regions of the heavy and light chains of antibodies in B-cell progenitors, mediated by a process called V(D)J recombination.

In this process, the DNA located between the rearranging gene elements is deleted from the chromosome (or sometimes inverted)." (NEJM -- Cellular Origin of Human B-Cell Lymphomas) The argument that is going to be presented in this essay revolves around the premise that each type of B-cell cancer reflects a different stage of B-lymphocyte development. It is therefore central to understanding of this essay that the relation between types of B-cell cancer and stages of B-lymphocyte be established.

As discussed above, the B cell enters into differentiation and directly become one of the two types of cell. However, B-cells can also go through an intermediate differentiation step - the germinal centre reaction where the B cell will hyper mutate the variable region of the antibody and possibly class switch.How Cancer BeginsIn any type of cell, the genetic code can produce abnormal types and amounts of proteins if it gets damaged and altered. This leads to abnormal behaviour of the cell and it continue dividing and stays alive contrary to normal instructions to rest or die.

The first cell to turn to abnormal growth control is known as the cell of origin. When it divides, the new cells inherit the same genetic behaviour of the cell of origin. Thus, the descendants are clones of this cell. This entails the beginning of cancer where cancer cells are growing with abnormal proportions and have growth and survival advantages over normal cells since they refute the normal genetic code. These cells may eventually form lumps called tumours.LymphomaThe cancer which affects the lymphocyte type of cells is known as lymphoma.

The b-cell in particular originates and differentiates in the bone marrow and around 85% of the lymphomas are of b-cell origin. "New findings about lymphoma made in the past two years by Dr. Dalla-Favera's lab have shown that the cancers develop with a mechanism unique to B cells, but that they are also vulnerable to some new experimental drugs". Other forms of lymphocytes comprise of the t-cell, which originates in the bone marrow but differentiate in thymus gland. A third kind of lymphocyte is of natural killer cells which are specialized in killing foreign threats and alerting other immune systems of such possible threats.

The different types of lymphoma are determined according to what type of lymphocyte has become cancerous, and the stage of development."Lymphoma is not one cancer, but a name for a group of related cancers that arise when a Lymphocyte (a blood cell) becomes malignant.The normal function of lymphocytes is to defend the body against pathogens