Tested genes explained
Immunological parameters
Interleukin-2
IL - 2 is a cytokine produced by immature CD-4 Th precursor cells, Th-0 cells and some Th-1 cells of the immune system. It is amplificatory in the release of pro-inflammatory cytokines which promote the proliferation of various active immunological cells displaying both anti-tumour and pro-tumour effects. High quantities are associated with increased activity of the defence system and a long-term increase can lead to the development of auto-immunity. Low quantities indicate that the cellular immune response is insufficiently active and in the long-term is associated with a decreased defensive ability of the immune system.
Interleukin-4
IL-4 is an anti-inflammatory cytokine mainly produced by the Th-2 cells of the immune system. It promotes the proliferation of various cells, including cancerous cells. IL-4 is also able to inhibit the production of pro-inflammatory substances produced by macrophages. A tumour can also produce IL-4 for self-proliferation. High quantities are associated with an active humoural immune response due to the presence of myco-bacteria and very occasionally parasites. A long-term increase may lead to the development of auto-immunity. Low quantities indicate that the humoural immune system response is non-active.
Interleukin-6
IL-6 is a pro-inflammatory cytokine produced by a range of cells and is associated with infections, trauma, inflammation, insulin resistance and auto-immunity. High quantities are frequently associated with infections and indicate a metastatic risk if there is a tumour. Low quantities indicate that there is a decrease of the response of the immune system to infection, trauma, etc. The nervous system and bones are also affected by high levels of IL-6. IL-6 could increase pro-tumour gene Bcl-2 expression thus altering the proliferation/apoptosis balance towards neoplastic cell proliferation. IL-6 can also activate telomerase to provide survival of aberrant/damaged cells.
Interleukin-10
IL-10 is an anti-inflammatory cytokine produced by some regulatory cells of the immune system and promotes humoural immunity associated with the Th-2 cells and the development of B-cells. It also has the ability to suppress the activity of the macrophages, the Th-1 cells, the NK cells and the dendritic cells of the immune system. However, high quantities of IL-10 act as an Immune-Activating Cytokine during an immunological anti-tumour response. Low quantities are associated with inefficient immuno-protection against the development of chronic inflammation.
Interleukin-12
IL - 12 is a cytokine produced mainly by macrophages, dendritic cells and, to some extent, by B-cells and is needed to develop normal immunological activity. Increased quantities are associated with active Th-1 cellular (destructive) immunity in response to a bacterial infection or some form of treatment. Low quantities are associated with a risk of low activity of the Th-1 type of immunity. The higher the extra-cellular level the more IL-12 producing cells have been destroyed.
Interferon gamma
IFN - γ is a cytokine produced mainly by the NK cells of the immune system having anti-viral and anti-proliferation properties. It amplifies the release of pro-inflammatory cytokines. High quantities indicates destruction, of primarily transformed or infected cells and suppression of angio-genesis (e.g., new capillaries) whilst inflammation takes place.
Interleukin-1 alpha
IL-1 alpha is a pro-inflammatory cytokine, mainly produced by the macrophages of the immune system in response to bacterial infection. It stimulates the production of pro-inflammatory prostaglandins. High quantities are associated with inflammation, disruption of liver and pancreas functioning and in cases of cancer a risk of liver metastasis. Low quantities are associated with a risk of decreased ability of the immune system to generate an acute defensive response.
Interleukin-1 beta
IL-1-b is a pro-inflammatory cytokine, mainly produced by the immune system macrophages, in response to infection. It is an endogenous pyrogen and is able to trigger oxidative stress as well as general stress mechanisms. A long-term increase will trigger neuro-degenerative processes. High quantities are associated with an acute phase of inflammation and alterations in liver and brain functions.
Interleukin-5
IL-5 is a pro-inflammatory cytokine produced by the Th-2 cells of the immune system. Increased quantities are associated with the presence of parasitic infections, allergens and inflammation due to the activation of eosinophils (i.e. defence system cells). If cancer is present active eosinophils can have an anti-tumour effect or pro-tumour effects.
Interleukin-8
IL-8 is a chemokine, mainly produced by stimulated blood monocytes. In addition to mononuclear cells, IL-8 is produced by other types of leukocyte cells (myeloid precursors, NK cells, neutrophils, eosinophils and mast cells), various tissue cells (fibroblasts, endothelial and epithelial cells) and tumour cells. The production of IL-8 can be induced by a variety of stimuli, such as the cytokines IL-1 and TNF-, bacterial, viral and plant products, etc. IL-8 activates the neutrophils which are cells of the innate immunity. High quantities of IL-8 are associated with the presence of bacterial or viral infections, inflammation, and in the case of a tumour, the promotion of its growth due to the stimulation in the formation of new blood capillaries around a tumour stimulation of telomerase activity. Low quantities of IL-8 are associated with insufficiently active neutrophils, monocytes and, possibly, cytotoxic macrophages.
Interleukin-17
IL-17 is a cytokine produced by the T-helper-17 active immunological cells which promote inflammation and auto-immunity. IL-17 induces the production of interleukins 6 and 8, granulocyte colony stimulating factor and prostaglandin E2. If the IL-17 is captured by the herpes virus it may interfere with the immune response against virus-infected cells or it may protect any infected cells against virus-induced death. Increased quantities are frequently associated with the development of diabetes. In some cases IL-17 can have pro-tumour effects. A persistently decreased quantity will make the gut vulnerable to yeast/fungal overgrowth.
Transforming Growth Factor beta
TGF-beta is an anti-inflammatory cytokine mainly produced by the th-3 type of lymphocytes. It is a multi-functional protein that is also produced by every cell including platelets, bones, spleen and haematopoietic cells. Its major effects include the production of the extra cellular matrix, regulation of cell growth and differentiation. Increased quantities are frequently associated with both inhibition of angio-genesis (formation of new blood vessels) and tumour suppression activity. Long-term high quantities may be linked to a parasitic infection and suppression of both the immunological and inflammatory response and neurotoxicity. Low quantities are associated with inefficient immuno-protection against the development of chronic inflammation. TGF-β can activate p53.
Tumour Necrosis alpha
TNF-α is a pro-inflammatory cytokine mainly produced by the macrophages of the immune system in response to various endotoxins and probable injury. High quantities trigger inflammation and destruction of some cells. Chronically high circulating levels of TNF-α lead to the development of sickness syndrome, flu-like symptoms, cachexia, anorexia, psychotic episodes, depression, sepsis and in many cases, the progression of any existing disease. TNF-alpha enhances the invasive properties of tumour cells. A persistently decreased quantity indicates insufficient activity of some immunological cells, such as monocytes and macrophages, weakening defence against many infectious species and cancerous cells.
Abnormal Cell Assays
P53 and Telomerase
There is a strong connection between p53 and telomerase. The major tumour suppressor p53 pathway prevents telomerase from becoming overactive. This means that any damaged or injured cells, which try to escape reparation or destruction, will be unable to proliferate indefinitely. Therefore, tumour growth may be avoided. If a major tumour suppressor p53 pathway malfunctions, either due to p53 gene mutation or a lack of p53 protein production or its mutation, telomerase can eventually become over-active. This means that the transformation of cells with mutated p53 into cancerous cells, which are able to form a tumour, is highly probable. The ratio between p53 and telomerase gene expression, together with the identification of the status of p53 protein, (e.g., wild or mutated), is used to evaluate the presence of any cells capable of forming a tumour. In addition, in some cases, misfolded p53 can promote the proliferation of metabolically abnormal cells without the activation of telomerase.
p53 gene
P53 is a major tumour suppressor gene, which becomes active when there is a need to prevent the transformation of any cells into cancerous ones. An activated p53 pathway will then trigger the reparation processes within the damaged cells. If reparation is not possible, the p53 pathway triggers programmed cell death (apoptosis).
Telomerase
Telomerase is a key enzyme that helps cells to continue self-replication. Limited replication occurs in stem cells (e.g, healing cells). Unlimited replication occurs in cancerous stem cells then become immortal. Telomerase activation, in pre-cancerous cells and the resultant growth of a population of cells with active telomerase, is considered a crucial step in cancer formation.
Bax
Bax is a major antagonist to the Bcl-2 gene (see below). It is mainly stimulated by wild (normal) p53 protein. It triggers programmed cell death (apoptosis) of cells, including cells with damaged DNA and in this capacity is considered as an anti-tumour gene. A dominance of Bax gene activity over Bcl-2 gene activity is a very important factor for cancer regression. Excessive Bax activity must be combatted by Bcl-2 activity to prevent self-destruction of healing cells.
BCL-2
Bcl-2 is a key inhibitor to programmed cell death (apoptosis). It is activated by mutated p53 protein in abnormal cells. Some other factors are also able to activate Bcl-2 particularly in healing cells. Persistently active Bcl-2 will eventually activate telomerase followed by transformation of abnormal cells into pre-cancerous and cancerous cells. In this connection Bcl-2 is considered as an oncogene. Some immunological factors are able to activate Bcl-2. In healing cells, active Bcl-2 protects them against destruction. Therefore, Bax gene activity should be less than Bcl-2 gene activity, in healing cells, for prevention of cell self-destruction.
P21
P21 promotes the self-destruction of transformed / abnormal cells and in this capacity it is considered as an anti-tumour gene and antagonist to the oncogene survivin (see below). P21 triggers the inhibition of any cell cycle followed by an arrest of cell proliferation. However, overactive p21 is able to trigger tumour growth or, make cancer cells dormant and therefore resistant to both destruction and proliferation. A long-term increase can have pro-tumour effects, however, one of its regulators is the p53 gene.
Survivin
Survivin is not active in normal mature cells. It is active in a developing foetus, and probably, in stem cells / cancer cells. It is involved in the suppression of programmed death (apoptosis) of any cells and stimulation of their proliferation. The ability of survivin to inhibit destruction of cancerous cells allows it to be considered as an oncogene. Some immunological factors are able to activate survivin. Resistance to apoptosis of cells with an active survivin gene, can be overcome by activation of the p21 gene, an agent which triggers necrosis (accidental cell death) and activation of anti-tumour immunological factors.
MMP-2
MMP - 2 is an enzyme mainly produced by the macrophages or some transformed cells. It assists in the destruction of the extra cellular matrix (ECM) surrounding the cells. High quantities indicate the destruction of ECM and a risk of damage to the normal cells, the blood brain barrier and also to the spread of any transformed cells present. Low quantities lead to decreased ECM degradation and hence excessive ECM accumulation which is damaging for the kidneys and is a feature of glomerulo-nephritis. Tumour necrosis factor alpha (TNF-alpha) produced by macrophages, can activate MMP-2.
MMP-9
MMP - 9 is an enzyme involved in the degradation of collagens of the extra cellular matrix. Increased quantities are associated with inflammation and the loss of control of angiogenesis (the formation of new blood vessels). There is a correlation between anti-apoptotic / anti-tumour Bcl-2expression and MMP-2 over-expression. Over-expression of MMP-9 is a significant risk factor associated with brain metastasis. Tumour necrosis factor alpha (TNF-alpha) produced by macrophages, can activate MMP-9.
VEGF
VEGF is a key factor in angio-genesis (i.e. neo-vascularisation or formation of new blood vessels). High quantities can be associated with tumour growth, due to an increased supply of nutrients and oxygen to the transformed cells, through the new blood capillaries. Low quantities may result in cardio-vascular problems due to a decreased supply of nutrients and oxygen to the normal cells. The processes of wound healing (i.e. after an operation or experiencing physical trauma) or pregnancy are accompanied by elevated VEGF quantities. Increased macrophages activity is one of the major factors of VEGF activation. Cytokine Interleukin-1-beta, produced by macrophages, is the prime activator of VEGF.
AFP
AFP is normally present in the tissues and plasma of the foetus and its concentration falls very rapidly after birth. In adults, AFP is produced in very low quantity in the liver. However, AFP production could be significantly increased in many types of cancer, especially primary hepato-cellular carcinoma. In some cases, a moderate increase may be temporary and associated with the tissue’s (usually the liver’s) response to injury.