| tumour escape | The ability of tumours to evade destruction by the immune system. Theories concerning possible mechanisms by which this takes place involve both cellular and humoral immunity, and also costimulatory pathways related to CD28 antigens and CD80 antigens. (12 Dec 1998) |
|---|---|
| tumour-infiltrating lymphocyte | <haematology, oncology> Special cancer-fighting cells of the immune system found in tumours. In a type of experimental therapy, scientists harvest these cells from the tumour, grow them in a laboratory and then return them to the patient with the hope of the cells destroying the tumour. These cells can be collected from the site of a tumour and exposed to IL-2 in vitro. When these cells are injected back into the tumour bearing host, they will specifically kill the tumour from which they originated. (05 Mar 2000) |
| tumour initiation | <cell biology, oncology> First stage of tumour development. See: tumour progression. (18 Nov 1997) |
| tumour lysis syndrome | <haematology, oncology, syndrome> A syndrome resulting from cytotoxic therapy, occurring generally in aggressive, rapidly proliferating lymphoproliferative disorders. It is characterised by combinations of hyperuricaemia, lactic acidosis, hyperkalaemia, hyperphosphatemia and hypocalcaemia. (12 Dec 1998) |
| tumour marker | <investigation, oncology> A substance in the body that usually indicates the presence of cancer. These markers are usually specific to certain types of cancer and are usually found in the blood or other tissue samples. Examples are alphafetoprotein (AFP), human chorionic gonadotropin, and lactate dehydrogenase (LDH). They may be indicators of tumour stage and grade as well as useful for monitoring responses to treatment and predicting recurrence. Many chemical groups are represented including hormones, antigens, amino and nucleic acids, enzymes, polyamines, and specific cell membrane proteins and lipids. (18 Jul 2002) |
| tumour necrosis factor | <cytokine> Originally described as a tumour inhibiting factor in the blood of animals exposed to bacterial lipopolysaccharide or Bacille Calmette-Guerin. Preferentially kills tumour cells in vivo and in vitro, causes necrosis of certain transplanted tumours in mice and inhibits experimental metastases. Human Tumour Necrosis factor alpha is a protein of 157 amino acids and has a wide range of pro inflammatory actions. Usually considered a cytokine. Synonym: cachectin. Acronym: TNF (13 Nov 1997) |
| tumour necrosis factor-beta | <cytokine> A cytolytic factor that is produced by CD4 and CD8 T-cells after their exposure to an antigen. (05 Mar 2000) |
| tumour progression | <oncology> Second stage of tumour development. See: tumour initiation. (18 Nov 1997) |
| tumour promoter | <molecular biology, oncology> Agent that in classical studies of carcinogenesis in rodent skin was able to increase the sensitivity of tumour formation by a previously applied primary carcinogen, but was unable to induce tumours when used alone. Important example was croton oil, active ingredients of which are now believed to be phorbol esters. These are believed to act as analogues of diacylglycerols and may activate protein kinase C. Strictly speaking, not the same as a co carcinogen, which is defined as being active when administered at the same time. Tumour promoters generally are carcinogens when tested more stringently. (18 Nov 1997) |
| tumour registry | Recorded information about the status of patients with tumours. Although a registry was originally the place (like registry house in edinburgh) where information was collected (in registers), the word registry has also come to mean the collection itself. A tumour registry is organised so the data can be analyzed. For example, analysis of data in a tumour registry maintained at a hospital may show a rise in lung cancer among women. (12 Dec 1998) |
| tumour specific antigen | <immunology, oncology> Antigen on tumour cells detected by cell-mediated immunity. For virus transformed cells TSTA (unlike T antigen) is found to differ for different individual tumours induced by the same virus. May consist of fragments of T antigens exposed at the cell surface. (18 Nov 1997) |
| tumour-specific transplantation antigens | Surface antigen's of DNA tumour virus-transformed cells, which elicit an immune rejection of the virus-free cells when transplanted into an animal that has been immunised against the specific cell-transforming virus. (05 Mar 2000) |
| tumour stage | <oncology> The extent of the spread of a malignant neoplasm from its site of origin. See: TNM staging. (05 Mar 2000) |
| tumour stem cell assay | <investigation> A cytologic technique for measuring the functional capacity of tumour stem cells by assaying their activity. It is used primarily for the in vitro testing of antineoplastic agent. (12 Dec 1998) |
| tumour stem cells | <cell biology> Colony-forming cells which give rise to neoplasms. (12 Dec 1998) |