Dictionary
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in vitro
This type of experiment is performed in a laboratory. Specific types of cancer cells are placed in a Petri dish, treated with the compound of interest, and the results are observed. In vitro (literally means 'in glass') studies are usually the first step in experimentation because they do not have the possibility of hurting animals or humans. Positive results in these kinds of tests show potential of working in humans. These results do not necessarily translate to what would happen inside the environment of the human body or inform researchers of side effects.
The addition of a small carbon compound, an acetyl group(COCH3), to target molecules, usually proteins. Acetylation of proteins changes their activity. The acetylation of histone proteins in our chromosomes is associated with an increase in the activity of the genes in that region. The removal of the acetyl groups is termed deacetylation and has the opposite effect. Antibody Dependent Cellular Cytotoxicity. This is a type of immune mediated cellular killing in which the target cell is coated with antibodies, labeling it for destruction by specific cells in the immune system. A DNA virus associated with human and animal disease. Adenoviruses cause one type of the common cold. A chemical that is able to transfer small hydrocarbons to other molecules. These agents are often mutagenic due to their ability to modify the nucleotides in DNA. Several different chemotherapy agents are known to be alkylating agents. They hinder tumor cell growth by damaging the DNA of the tumor cells. For examples, see the treatment section of the site. alternate versions of the same gene. As an example, the gene that control whether you can roll your tongue has more than one version. This is why some people can roll their tongues and some people can not. Defective versions (alleles) of genes are associated with diseases such as cystic fibrosis.
Note that since we have two copies of each chromosome, one from each parent, that we have two copies of each of our 30,000 or so genes. These two versions can be the same (same allele) or they can be different. Shown below is a pair of chromosomes with 'genes' marked in different colors. The chromosomes are shown as they would appear during cell division. If you compare bands (genes) at the same location on the two chromosomes (male and female) you4ll see that some of the bands are the same, indicating that the two alleles are the same, and that some bands are slightly different, indicating two different versions, or alleles. A monomer building block used to build proteins. Of the many different known amino acids, twenty of them make up the bulk of our protein content. All amino acids are composed of three different components. They share two common components; a carboxyl (COOH) group and an amino (NH2) group. They also contain a variable portion, the R group, that differs. It is the nature of the R group that determines the functional capabilities of any given amino acid. As an example, the amino acid valine has an R group that is comprised entirely of carbon and hydrogen. This makes this portion of the molecule hydrophobic. For this reason, valine is found in regions of proteins that are not exposed to water. also: gene amplification. This refers to an abnormal process in which many copies of the same chromosome region are produced via DNA replication. The result can be a small 'microsatellite' chromosome or a region of DNA within a chromosome with many copies of a small set of genes. This process occurs often in cancer cells. The genes involved are often oncogenes or genes that promote chemotherapy drug resistance. Genetic imbalance caused by the loss or gain of one or a few chromosomes. Cancer cells are very often aneuploid. The abnormal numbers of chromosomes means that gene expression and the regulation of cellular functions is severely deranged. One of the most familiar aneuploid conditions in a non-cancerous disorder is Down syndrome. In this disorder, the child inherits three copies of chromosome 21 instead of the normal two copies. The extra genetic information leads to developmental and neurologic abnormalities. The formation of blood vessels. This process is required for a tumor to grow past a small size since the blood delivers nutrients to the cells in the mass. Much work has been done to find agents that can block the development of blood vessels in tumors. The blockade should lead to the 'starvation' of the tumor cells and tumor regression. Also: Immunoglobulins. Antibodies are proteins produced by a type of white blood cell (B-cells or B-lymphocytes). These proteins bind to foreign materials (antigens)in our body and aid in their elimination. Cancer cells may sometimes express proteins on their surface that may be targets for antibodies. Our bodies contain thousands of different antibodies, produced by different groups of B-cells. See antibodies. Any substance that is capable of being recognized by the immune system. Recognition of such a substance leads to the generation of an immune response. If the antigen is located on a bacteria, the immune system will work to eliminate the infection. Antigens are usually made of protein but can also contain carbohydrates or even lipids. With regard to cancer, antigens play two key roles: Drugs that interfere with the formation of key biomolecules within the cell. They often work by blocking the activity of enzymes These drugs often prevent the normal replication of DNA and therefore cell division. Other antimetabolites may interfere with the creation of RNA or other cellular processes. Also called programmed cell death. The death of the cells is a carefully controlled process that does not generate any inflammation. Apoptosis is a natural process that occurs throughout the lives of almost all plants and animals. It is a way to balance the production of new cells and to remove damaged cells. Some examples of apoptosis include the loss of a tadpole's tale and the loss of leaves from trees in the Fall. In cancer, induction of apoptosis is beneficial if the process causes the death of the abnormal cells. Many cancer drugs are designed to induce apoptosis. Successful tumors have acquired the ability to avoid at least some triggers of apoptosis. A way in which traits are passed down through families. An autosomal dominant trait only requires one abnormal copy of the gene in order to inherit the trait or syndrome. Singular: bacterium. Also: basement membrane. See basal lamina. An protein that works to inhibit apoptosis (cell death). The gene was intially described in a B-cell lymphoma, from which it got its name. A growth that does not leave its site of origin or invade surrounding tissue. While not generally as dangerous as malignant tumors, benign growths can get large and are capable of causing illness or even death, depending on the location of the growth. A multi-functional protein that interacts with the cytoskeleton, aiding in the ability of the cell to react to extracellular signals and interactions. The protein also acts in the nucleus as a transcription factor, turning on genes that drive cell division. Also: Tositumomab. A monoclonal antibody currently being evaluated for the treatment of non-Hodgkin's B-cell lymphoma. This antibody is different from others in that a radioactive molecule, I-131 has been attached to the antibody. The binding of the antibody the target cells acts to deliver the radioactive material, leading to DNA damage and ultimately, the death of the cell. Also called BRM, these are agents that can potentiate the body's own response to an infection or a cancerous growth. Very often these agents are proteins that are produced naturally by our bodies. The proteins can be made in the laboratory and then injected back into the patient. Examples of these types of agents include alpha-interferon, gamma-interferon and interleukin 2 (IL-2). The goal of all of these therapies is to allow the patient's immune system to work at its best to eliminate the foreign invader or tumor. An invasive medical procedure in which a sample of tissue is removed for examination. Biopsies can be done in several ways, ranging from a small sample drawn into a needle to samples taken during more invasive surgery. The samples are then examined for evidence of disease. The tight connections between the cells lining blood vessels and capillaries in the brain block the passage of most substances from the blood into the fluid area surrounding the brain and the brain itself. This blockage creates a challenge for the delivery of anticancer drugs to tumors located in the brain. Also: 'lumpectomy'. A surgical procedure in which a growth is removed from a breast with as little additional breast tissue as possible. A transcription factor that controls the expression of several genes involved in cell division. The mutant form of this gene acts as an oncogene and is found in cancers of several types including neuroblastoma. A glycoprotein secreted by some ovarian cancer tumors into the bloodstream. The protein can be detected in the blood and is used to monitor the progression of those cancers. A sugar monomer, dimer or polymer. Sugars are comprised of carbon, hydrogen and oxygen. Carbohydrates are used for energy and for building structures such as the cell walls of plants. Carbohydrates are often added to other biomolecules such as proteins and lipids to form complex mixtures. The sticky nature of carbohydrates is utilized to allow different molecules to adhere to each other. An agent that is able to cause cancer. Many of these are chemicals that cause changes (mutations)in DNA. Radiation is another type of carcinogen. Cancer of epithelial cells. This is the most common form of cancer, accounting for up to 90% of all cancers. A substance that is able to speed up a reaction without undergoing any chemical changes itself. The most common type of catalyst in biological systems are made of protein and are termed enzymes. A carbohydrate molecule composed of many linked molecules of the monomer sugar glucose. Cellulose is the primary building blocks of plant cells and a major component of wood. Cellulose is not digestible by humans and makes up the bulk of the dietary component often called fiber, bulk or roughage. A cylindrical array of microtubules located in the cytoplasm of animal cells. Centrioles are found in pairs, with the cylinders essentially perpendicular to each other. They are surrounded by a network of microtubules to form a larger complex termed a centrosome. Centrioles may function in the organization of the spindle fibers during cell division. A subcellular structure that includes a pair of centrioles. The centrosomes at the ends of a dividing cell are at least partially responsible for the organization of the microtubules in the spindle. The spindle helps to separate the chromosomes and divide the cell. Treatment of cancer patients with anticancer drugs. Commonly called chemo. These drugs are often very toxic, with severe side-effects such as nausea and vomiting. These drugs all work by attacking cell growth or division. Many of these agents are only effective at specific times during the cell division process. Often these agents are used in combination to take advantage of their different modes of attack on cell division. A type of lipid, cholesterol is part of a group of molecules called steroids. Testosterone and estrogen are other steroids that are very similar to cholesterol in structure but not function. Cholesterol is essential for the structure and function of our cellular membranes. Contrary to the entirely negative reputation cholesterol has in the popular press, it is required for normal life processes. Cholesterol can be obtained in the diet or produced from precursors in our bodies. A combination of DNA and proteins. Our chromosomes are composed of DNA that is twisted around proteins much like thread on a spool. In addition to structural roles, the proteins also aid in the replication and cell division processes. Some of these proteins, the topoisomerases, are targets of chemotherapy drugs such as etoposide (VP16) and topotecan. See also, 'nucleic acid'. A long DNA molecule containing genetic information (genes). Humans have 46 chromosomes. One set of 23 is inherited from each parent. The DNA molecules are extremely long and contain millions to hundreds of millions of nucleotides strung together. Our chromosomes reside in the nucleus within each of our cells. See also, 'nucleic acid'. Also: CLL. A cancer of B-lymphocytes (B-cells)in which the number of cells in the bone marrow, blood and tissues increases gradually with time. Please see the Clinical Trials section. A string of three nucleotides along a messenger RNA (mRNA) molecule that encodes a single amino acid. Ribosomes are able to 'read' the encoded message in an mRNA and synthesize proteins from amino acids present in the cell. A surgical procedure that creates a way to drain waste from the large intestine. Colostomies can be permanent or may be reversed. A colostomy may be necessary after surgery to remove colorectal or anal cancer. See the entry for antibodies. A device used to prevent pregnancy. Oral contraceptives used by women contain different mixtures of hormones such as estradiol and progesterone. Computed Tomography. A non-invasive, X-ray based technique for imaging internal structures and identifying disease. May involve the use of an injected 'contrast' agent such as iodine. The images are analyzed by computer and can produce many 'slices' through the target organ or tissue. Naturally occuring proteins or synthetic drugs that block the activity of cyclin-dependent kinases. The actual division of a cell into two daughter cells. This is a normal process and leads to cells that allow for growth of organs/tissues or replacement of dead cells. The two resultant cells are genetically identical to the parent cell. The portion of a cell that is located outside the nucleus. This includes many organelles such as ribosomes and mitochondria. The cytoplasm also contains many fibers of the cytoskeleton. Compare to cytosol. The dense network of wire-like proteins that crisscrosses the cytoplasm of a cell. The cytoskeleton is responsible for giving a cell shape, anchoring organelles and allowing cellular movement and attachment. A wide range of proteins form the cytoskeleton, including actin and tubulin. Tubulin is used to form microtubules, targets of some chemotherapy agents. The semi-liquid portion of the cell outside the nucleus, excluding the organelles. Compare to cytoplasm. Having the ability to kill a cell. Many of the chemotherapy drugs are cytotoxic, as is radiation. Cells of our immune system also have the ability to recognize and kill certain cells, such as virally infected cells or cancer cells. again The unfolding of a protein. A protein's function is exquisitely tied to its proper shape. Denaturing of proteins can be accomplished by heat, chemicals or biological(enzymatic) means. An example of denaturing proteins is a cooking egg. The clear part of the egg becomes white as the proteins denature from the heat. The maturation of a stem cell into a fully functional cell. In many tissues, only a small set of immature cells are capable of cell division. The products of the divisions may go through a series of changes that alter the cell shape a functions. An example would be the maturation of a single type of precursor cell into several different type of blood cell. The only covalent bond between the amino acids of a protein. Disulfide bonds (S-S), between the sulfhydryl groups of two cysteines are very strong and help to give proteins their structures A semi-synthethic drug (a maytansinoid derivative) that works to kill cancer cells by inhibiting microtubule function. Abbreviation for deoxyribonucleic acid. Composed of very long strings of nucleotide monomers. This is the storage form of our genetic material. All of the instructions for the production of our proteins is encoded in our DNA. Genes are comprised of short stretches of DNA. Our DNA is arranged into chromosomes. There are about 6 billion nucleotide pairs in the DNA of a single cell. Changes to the nucleotide sequence of the DNA are called mutations. Many chemotherapy agents work by altering the structure of DNA. These changes disable the cells and prevent them from dividing. An abnormal condition in which cells may have altered morphology (shape) or may divide in a manner that alters the appearance of the tissue or organ. This often occurs in rapidly dividing cells and may be a precursor to cancerous growth. The portion of a membrane protein that is exposed to the extracellular space. Refers to the endometrium, the inner lining of the uterus. The endometrium is a common site of cancer. A membranous hollow subcellular organelle. The ER is actually an extension of the outer nuclear membrane. A protein that speeds up the process of chemical reactions in the body. The proteins act as catalysts; they speed up the reactions without getting altered in the process. Almost every biological process is driven by the activity of enzymes. Without them, the complex reactions that we need to build and breakdown cell parts would not happen at a rate that is compatible with life. Enzyme names usually describe the reaction that is being catalyzed and all of them end in -ase. In addition to actual alterations in DNA sequence, gene expression can be altered by changes to the DNA and chromatin that do not change the DNA sequence. Since these changes do not alter the sequence of the DNA in the genes, they are termed epigenetic changes. Two types are epigenetic changes are described below.
Also called epithelium. A type of tissue that covers our exposed surfaces, such as our skin. Also lines our hollow or tube-like organs/tissues such as our digestive tract. Since these tissues are often exposed to environmental insults such as chemicals and radiation from the sun, and are often rapidly dividing to replace lost cells, many cancers arise in epithelial tissues. Also: endoplamic reticulum. A subcellular structure that is part
of a large network of membranes within the cell. The ER membrane is an extension
of the outer nuclear membrane. The ER has two structurally and functionally
distinct regions.
See HER2/neu. A steroid sex hormone. Estrogen has a structure that is closely related to cholesterol. Produced by the ovaries, estrogen has effects on the reproductive, cardiovascular and skeletal systems. Estrogen is also a growth factor for some types of cells, including breast cells. Inhibitors of estrogen function such as tamoxifen are used to block the growth effects of estrogen. See also, estrogen receptor. Abbreviated as ER. A protein located within cells that binds estrogen. The protein:estrogen complex then binds to DNA to increase the transcription of certain genes. The estrogen receptor therefore is a type of transcription factor. The estrogen receptor is the target of the anticancer drug tamoxifen. By binding to the ER, tamoxifen blocks the growth promoting effects of the hormone. A cell containing membrane bound organelles and a membrane enclosed nucleus. This is in contrast to bacteria, which are microbes that do not contain a nucleus. Humans are eukaryotic organisms. A typical eukaryotic cell is shown below. A complex of proteins and glycoproteins that surrounds the cells in our tissues and organs. The extracellular matrix is used for attachment and to help organize the cells. Also: FAP. An inherited form of colon cancer characterized by the development of hundreds to thousands of colonic polys. Most of these growths are harmless but some eventually progress to malignant growths. For 'fraction crystallizable'. The constant region of an antibody. Antibodies are composed of two functionally different parts. The variable portion is responsible for binding to the target antigen and the constant portion is often recognized by cells of the immune system. These refer to two the stages of the cell division cycle. During these phases, the cells are growing and preparing to undergo the changes necessary for cell division. The cell cycle is divided into four stages. The remaining two are the S phase which is the time of DNA duplication and the M phase during which the cell actually splits into two daughter cells. The daughter cells have the exact same genetic information as the parent cell. A cell involved in reproduction; sperm and eggs. Gametes contain only half the genetic information of a typical cell. When two cells of this type fuse via the process of fertilization, the offspring formed has the full complement of genetic information. In the case of humans, each gamete contains 23 chromosomes and the embryo has 46 chromsomes. A stretch of DNA that leads to the production of an RNA. The RNA is produced during the process of transcription. This RNA can be used to guide the formation of a protein via translation or can be used directly in the cell. An advanced and relatively new method for monitoring gene expression. The differences between normal cells and cancer cells can be analyzed by examining the activity of thousands of genes simultaneously. The act of transcription and, if needed, translation of a gene. Regulation of gene expression is tightly regulated. Genes must only be expressed in the correct cells, at the right time and in the correct amount. Abnormal gene expression is always found in cancer. The full set of genes in an organism. Humans have an estimated 30,000 genes in their genome. Refers to agents that either directly or indirectly cause damage to cellular DNA. Some cancer causing agents, such as benzo-a-pyrene, found in cigarette smoke are genotoxic. These agents cause mutations and can lead to changes in proto-oncogenes and tumor suppressor genes. A large number of chemotherapy drugs are also genotoxic. Examples include cisplatin, carboplatin and doxorubicin. These agents kill cancer cells by damaging their DNA, preventing cell division. The side effects seen with many cancer treatments are a result of their genotoxic effects on normal cells in the body. A group of cells located in the brain and nervous system. Glial cells do not conduct nerve impulses but they support the neurons that do serve this function. Glial cells are very numerous and far outnumber neurons. A group of steroid hormones derived from cholesterol and produced in the adrenal gland. The majority of the activity related to glucocoricoids in humans is due to cortisol (also called hydrocortisone). This hormone is elevated in response to stress and has effects on many different aspects of human physiology including the ability to suppress the immune system. A carbohydrate molecule composed of a long string of glucose subunits. Found in the liver and muscles of mammals; glycogen is the stored form of carbohydrates within the body. A lipid with a carbohydrate molecule or molecules attached to it. The phospholipids that make up our cell membrane are sometimes modified by the addition of carbohydrates. A protein that has been modified by the addition of one or more carbohydrates. Many proteins are modified in this way. The addition of the sugar molecules alters the properties of the protein and often aid in the function of the protein. Many proteins that are located on the outside of our cell membranes are glycoproteins. The blood tests used to detect cancer often are actually detecting small amounts of glycoproteins that are produced by the particular cancer cells. For instance, both the prostate specific antigen (PSA) test used to detect prostate cancer and the CA125 test used to track ovarian cancer growth are actually monitoring the abundance of different glycoproteins that are released by the tumor (and sometimes normal) cells. A series of sac-like, membrane enclosed areas of the cytosol. The golgi apparatus is responsible for the processing of proteins secreted from the ER and shipment of those proteins to their final destinations. Vesicles leaving the golgi can go to other organelles or may fuse with the plasma membrane, releasing the contents into the space around the cell(the extracellular space). A substance that stimulates cell division. Growth factors are usually small proteins or steroid hormones. They may be secreted by the same cells on which they act or by cells that may reside in a different part of the body than the target cells. Also: erbB-2. A transmembrane growth-factor receptor. This protein is found at very high levels on some breast and ovarian cancers and may be a prognostic factor in these types of cancer. The state of having two different forms of any particular gene. Humans have two full sets of genes, one obtained from each parent. Although the each set has the same genes, they may not be exactly the same forms for each gene. Variations in the genes give us a wide range of different characteristics. Examples would be genes involved in the production of pigments. Variations in these genes give us black, brown, blonde or red hair and all the colors in between. When the versions of a gene received from both parents are the same, the genes are said to by homozygous. When they are different then the genes are heterozygous. Homo- and hetero- refer to same and different, respectively and -zygous refers to the formation of a zygote or embryo. A group of proteins that combine to make a 'bead' around which our DNA is wrapped. The bead consisting of DNA and histones is called a nucleosome. Hereditary Non-polyposis Colorectal Cancer. A hereditary form of colon cancer. This colon cancer is not associated with the development of colonic polyps. Another familial form of colon cancer, FAP (familial adenomatous polyposis), is characterized by the development of hundreds or thousands of polyps in the large intestine. While most of these growths are benign, some inevitably progress to a malignant cancerous state. A chemical produced by cells that alters the activity of other cells. The chemicals may be lipids, such as testosterone and estrogen or proteins like insulin. Hormones may act at locations far from their site of origin. Estrogen, for example, is produced primarily by cells in the ovaries but acts on cells in the breast and elsewhere. Describes molecules which readily interact with water or other polar molecules. From hydro-water and philic-loving. Our blood, body fluids and the insides of our cells are all composed mostly of water. Describes molecules which do not interact with water or other polar molecules. From hydro-water and phobos-fearing The lipid hormones and fat are examples of hydrophobic molecules. Insulin-like growth factor type 1. A potent growth factor. Elevated levels of IGF-1 have been found in the blood of patients with certain types of cancer, including breast cancer. Refers to the fact that once our immune system has encountered a particular substance (antigen) that causes the generation of an immune response, any subsequent response to that antigen is much more rapid and more rigorous. A treatment for a disease (including cancer) that involves the modulation of the immune system. Treatments include the administration of cytokines ( proteins produced by cells of the immune system), vaccination and even treatment with antibodies such as the breast cancer treatment, Herceptin.. From the Latin; in place. Often written in italics. Refers to the detection of a process or molecule which is examined in its original location. This is in contrast to in vitro, which refers to processes or molecules examined in testtubes. A reaction to cellular damage or tissue invasion. Small blood vessels become leaky, leading to redness, swelling and the infiltration of the area with cells of the immune system. A protein hormone secreted by the pancreas. Insulin controls glucose levels in the body by increasing uptake of glucose into cells of the body. Insulin also has stimulates the formation of glycogen and alters fat and protein metabolism. One of a group of protein messengers produced by cells of the immune system and some other cells. Interferons can help cells to defend themselves against viral infection and are currently being evaluated for their ability to increase the body's ability to eliminate cancer cells. Types of antibody (immunoglobulin) molecules. While all antibodies have a similar basic structure and function, there are several different sub-types with different capabilities. For example, some antibodies are able to be recognized by cells of the immune system so that coated targets can be destroyed and other antibodies lack this property. An enzyme that adds phosphate groups to another molecule. Many of the key regulatory proteins in the control of gene expression are targets of kinases. The addition of a phosphate group to a protein by a kinase can alter the activity of the protein and are often used as molecular on/off switches. For example, the retinoblastoma tumor suppressor gene is 'off' when phosphate groups are added to the protein at specific locations. Removal of the phosphate groups turns the protein 'on'. Enzymes that remove phosphate groups are known as phosphatases. Note that all enzymes, regardless of function, end in ASE This is a broadly used term in pathology and refers to any defined (localized) structural abnormality or injury. The word 'lesion' does not imply that something (i.e. a tumor) is necessarily serious or advanced. A cancer affecting the cells that develop into white or red blood cells. From leuko- white and -emia referring to blood. Both of these cell types originate in bone marrow. Red blood cells function to carry oxygen to our tissues and the white cells (leukocytes) are part of our immune system. The cancerous cells often accumulate in the blood. A class of biomolecule. Lipids all share a common feature in their hydrophobic nature. Lipids are one of four classes of biomolecules that make up the majority of the materials in our cells. The others are proteins, carbohydrates and nucleic acids. A surgical procedure in which a tumor is removed with as little surrounding tissue as possible. A grape-like cluster of rounded lymphatic tissue. Lymph nodes (or lymph glands) filter the lymph fluid that flows through the lymphatic system. The lymphatic system is a large network of vessels that carry fluid and cells of the immune system around the body. Lymph nodes are regional collection centers in the lymphatic system. Fluid from the areas surrounding the lymph nodes drains into the lymph nodes just like smaller streams fuse to form a larger river. Cells from tumors may break off the primary tumor and get carried to a nearby lymph node. The lymphatic system is a primary mechanism for tumors to move, or metastasize, to other parts of the body. A immune cell that resides primarily in the lymphatic system. The lymphocytes include A cancer arising in the lymphatic system. The white cells affected are part of the body's immune system. The lymphatic system is a large network of vessels that carry fluid and cells of the immune system around the body. Lymph nodes are regional collection centers in the lymphatic system. See also, 'lymphatic system'. A subcellular organelle responsible for the digestion of intracellular debris such as defective or unneeded proteins, lipids and carbohydrates. Ingested cellular debris from dying cells is also digested by lysosomes. These small sac-like structures contain numerous destructive enzymes that rapidly break large molecules down to their components. The released components can then be re-cycled in the cell. Also: Rituximab, Rituxan.. A monoclonal antibody used to treat non-Hodgkin's lymphoma. A tumor that is likely to invade neighboring tissue and metastasize. A diagnostic procedure that involves taking an X-ray of the breasts. Changes due to cancer growth can often be seen in the images produced. More on ths topic can be found in the pages on breast cancer detection. A group of secreted enzymes that are able to degrade the basal lamina and allow for cancer cell migration. These enzymes are capable of degrading a wide range of extracellular proteins, such as collagen. The enzymes derive their name from the fact that they are secreted into the extracellular matrix and they have a requirement for metal ions in order to function properly. 1. cell membrane-A very thin barrier between the cytoplasm and the extracellular space. Cell membranes are composed mainly of lipids and proteins. A hallmark of cellular membranes is their selective permeability to certain ions and other molecules. 2. tissue membrane- a thin layer of cells or protein matrix that separates adjacent portions of organs or tissues. In order for tumors to metastasize, they usually have to encounter and break through a membrane, such as the cells of blood vessels. The sum of all reactions in a cell or animal. The processes that lead to the creation of biomolecules such as proteins and nucleic acids are termed anabolic pathways. The processes in which biomolecules are broken down, such as the digestion of foods, are termed catabolic. Metabolism is a term that encompasses both of those sets of processes. Tumor growths located at a location distinct from the initial site of cancer development. Also: see the animation at ' metastasize '. The movement of a cancer to a location outside its site of origin. The distant growths are termed metastases
The term for a cancer that has spread beyond its point of origin. Metastatic disease is reponsible for the majority of cancer deaths. Organisms that are too small to be seen with the naked eye. Microbes include bacteria, viruses and some fungi. A cable-like structure that is part of the cytoskeleton. Microtubules are composed of long chains of the protein tubulin. They serve to give a cell shape, aid in cellular motility and are very important in cell division. Microtubules are dynamic and grow and shrink depending on the needs of the cell. (see animation below.)
Subcellular organelles. Mitochondria are responsible for extracting the bulk of the energy we use from the food we eat. As a byproduct of this activity, oxygen radicals (reactive chemicals) are produced that may contribute to cancer formation by damaging DNA. A cut-away view of a mitochondrion (the singular version of the word) is shown below, revealing the inner membranes of the organelle.
acetylation
ADCC
adenovirus
Adenoviruses are currently being explored for their potential use as gene-delivery devices for gene therapy.
alkylating agent
allele
amino acid
amplification
aneuploidy
angiogenesis
antibodies
Monoclonal antibodies are those that are all derived from a single type of B cell. Monoclonal antibodies are currently being used as anti-cancer drugs. An example of a monoclonal antibody used for the treatment of cancer is Herceptin.. This antibody is directed against a protein that is present at very high levels on the surface of some cancers, including some breast and ovarian cancers.
The attachment of drugs to monoclonal antibodies allows for the specific delivery of the drugs to the cells bearing the correct receptor. This is a way of delivering drugs specifically to tumor cells. The modified antibodies are called conjugated monoclonal antibodies
antibody
antigen
1) If an antigen or group of antigens on the surface of a cancer cell can induce an immune response, the cancer cells may be eliminated. Since cancer cells are abnormal, they often display unusual proteins on their surface and may induce an immune response.
2) Antigens may be introduced to the body via vaccination. This is an attempt to 'wake up' the immune system and get it to recognize similar antigens on the surface of cancer cells.
antimetabolites
apoptosis
autosomal dominant
bacteria
Single-celled organisms that lack many of the organelles and structures found in our cells.
Bacteria do not contain a membrane-enclosed nucleus and are therefore called prokaryotes. Organisms whose cells contain a nucleus, including humans, are termed eukaryotes.
Examples of bacteria include the gut organism, E. coli and the disease causing Strep. pneumoniae.
basal lamina
A layer of proteins and glycoproteins that surrounds our tissues.
Cancer cells that are in the process of metastasizing must cross the basal lamina to enter blood vessels or other areas of the body.
basement membrane
bcl-2
There have been several proteins identified that are similar in structure and function to bcl-2 and an entirely different set of proteins whose function seems to be exactly the opposite. The life of a cell apparently hangs in the balance as these two sets of protein work against each other. A change in the cell that tips the scales towards the bcl-2 proteins will allow the cell to live.
benign
beta-catenin
Bexxar.
biological response modifier
biopsy
blood brain barrier
Breast Conserving Treatment (BCT)
c-myc
CA-125
carbohydrate
carcinogenic
carcinoma
catalyst
cellulose
centriole
centrosome
chemotherapy
cholesterol
chromatin
chromosome
chronic lymphocytic leukemia
clinical trials
codon
As an example the codon AUG in an mRNA leads to the incorporation of the amino acid methionine into the growing polypeptide (protein). Some codons are used for 'punctuation', so that the codon UAA leads to the termination of the protein chain.
colostomy
conjugated monoclonal antibody
contraceptives
CT scan
cyclin-dependent kinase inhibitors (CKI)
These kinases (enzymes that attach phosphate groups to targets)are critical in the progression through the cell cycle. Inhibition of these enzymes would be expected to inhibit cell division and therefore, in the case of cancer, tumor growth.
cytokinesis
cytoplasm
cytoskeleton
cytosol
cytotoxic
de novo
denature
differentiation
The mature cells often have very different appearances and functions in the body despite the fact that they are derived from the same type of precursor or stem cell.
Fully differentiated cells often are incapable of cell division and many cancers are thought to arise via alterations in stem cells.
The cells in cancerous states also tend to become more like their precursor stem cells through a process of de-differentiation. Some anti-cancer drugs are designed to force cells to differentiate, reducing their ability to reproduce.
disulfide bonds
DM1
Current trials with this drug involve the attachment of DM1 to monoclonal antibodiesto allow for delivery specifically to tumor cells.
The products are being developed by several companies, including ImmunoGen, Inc.
DNA
dysplasia
ectodomain
endometrial
endoplasmic reticulum (ER)
The ER has two structurally and functionally different regions,1) the rough ER, responsible for the modification and export of proteins, and 2) the smooth ER, which among other things, detoxifies drugs, manufactures steroid hormones and helps to build cell membrane components.
enzyme
epigenetic
epithelial
ER
Proteins produced by the RER and SER can be packaged into vesicles and sent
to other locations in the cell or to the outside of the cell. Many vesicles are sent
from the RER to the golgi apparatus, where the contents of the vesicles are
processed.
erbB2
estrogen
estrogen receptor
eukaryote
extracellular matrix
Cells can attach to the extracellular matrix via proteins on their surfaces.
familial adenomatous polyposis
Another inherited form of colon cancer, HNPCC, does not present with polyps.
FAP is often diagnosed via colonoscopy.
Fc region
In ADCC, the Fc region of the antibodies bound to the target cell are recognized by cells of the immune system, leading to the death of the target cell.
G1 and G2
gamete
gene
gene chip
Gene chip analysis is being investigated for its potential in the diagnosis and treatment protocol design for several cancer types.
gene expression
genome
genotoxic
glial cells
glucocorticoids
glycogen
glycolipid
glycoprotein
golgi apparatus
growth factor
Some examples of growth factors include estrogen, a growth factor for breast cells and VEGF, a growth factor that causes the development of blood vessels.
Several different anti-cancer treatments are designed to inhibit the activity of growth factors.
HER2/neu
The cancer treatment Herceptin. (is a monoclonal antibody selected to attack cells that express high levels of this protein on their surface.)
heterozygous
histones
HNPCC
Both of these disorders may be detected via colonoscopy.
hormone
hydrophilic
hydrophobic
IGF-1
Immunological memory
Immunological memory is the basis for vaccinations, in which a small dose of an antigen is given so that a future exposure to a disease causing organism will result in rapid removal of the invader from the body.
In cancer, vaccinations are given to boost the response of the body against antigens present on cancer cells.
immunotherapy
in situ
As an example, the production of a particular protein can be detected by looking into the cell while it is still whole (in situ) or after breaking the cell open and separating its parts (in vitro).
inflammation
insulin
interferon
isotypes
The main isotypes are IgG, IgM, IgA, IgE and IgD.
kinase
lesion
leukemia
lipid
lumpectomy
lymph nodes
Lymph nodes collect fluid from discrete regions of the body and are often examined for the presence of metastasizing cancer cells.
See also lymphatic system
lymphatic system
lymphocyte
1) T-cells: Cells involved in the control of immune responses and cellular cytotoxicity
2) B-cells: Cells that produce antibodies (immunoglobulins).
lymphoma
lysosome
Mabthera
Learn more about Rituximab from Genentech.
malignant
mammogram
matrix metalloproteases
Matrix metalloproteases (MMP) are key to cancer metastasis as they enable the moving cells to cross barriers such as the basal lamina
membrane
metabolism
metastases
metastasize
metastatic
See also: the animation at ' metastasize '.
microbe
Infection with microbes poses a serious threat to patients with cancer.
microtubule
The anticancer drugs taxol, vincristine and vinblastine (and their derivatives) all work by interfering with the function of microtubules.
mitochondria
