[gdpawel]

Amelia

Granulocyte colony-stimulating factor is one of the about 15 proteins known to activate endothelial cell growth and movement. At a critical point in the growth of a tumor, the tumor sends out signals to the nearby endothelial cells to activate new blood vessel growth.

A growth factor is about twenty small proteins that attach to specific receptors on the surface of stem cells in bone marrow and promote differentiation and maturation of these cells into morphotic constituents of blood. And blood is a circulating tissue composed of fluid plasma and cells (red blood cells, white blood cells, platelets). Problems with blood composition or circulation can lead to downstream tissue (which is made up of cells) dysfunction.

Colony-stimulating factor is a substance that stimulates the production of blood cells. Colony-stimulating factors include granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), and promegapoietin.

Examples:

White Blood count boosters = Neupogen (Filgrastim ), Neulasta (Pegfilgrastim), Leukine (Sargramostim)

Red Blood cell boosters: Procrit, Epogen (epoetin alpha, Erythropoietin), Aranesp (Darbepoetin)

The agents include epoetin alfa (Epogen, Procrit), epoetin beta (NeoRecormon), and darbepoetin alfa (Aranesp). Neulasta has to do with wbc (white blood cells) and pricrit has to do with rbc (red blood cells).

Blood is a circulating tissue composed of fluid plasma and cells (red blood cells, white blood cells, platelets). Problems with blood composition or circulation can lead to downstream tissue (which is made up of cells) dysfunction.

The big difference is that white blood cells help fight infection, red blood cells transport oxygen throughout the body.

Erythropoiesis is basically a process where hemoglobin is synthesized, and eventually passes into the bloodstream.

Erythroprotein (EPO) is a natural substance made by the kidney.

Pharma EPO is a hormone that stimulates bone-marrow cells to produce red-blood cells.

Tumors create their own supply lines by secreting substances that stimulate the formation of new blood vessels. Pharma EPO is helping them along (growth factor).

Drugs that would stimulate white blood cells would not involve erythropoiesis (above). They would be involved with leukopoiesis, the process of making leukocytes, stimulated by various colony-stimulating factors (CSFs), and hormones produced by mature white blood cells.

Growth factors cause endothelial cell (the cells that line blood vessels) to produce chemicals that break down the nearby tissue and the extracellular matrix (the spaces between cells). Then the endothelial cells divide into more cells and begin building new blood vessels. Other elements, such as stromal cells (cells that form connective tissue), provide "structural support" for the new blood vessels.

Greg