Powdered Cartilage Products
Aqueous Extracts of Cartilage

The antitumor potential of cartilage has been investigated extensively in laboratory and animal studies. Some of these studies have assessed the toxicity of cartilage products toward cancer cells in vitro.[1,2] Reviewed in [3-6]

In one study, cells from 22 freshly isolated human tumors (nine ovary, three lung, two brain, two breast, and one each of sarcoma, melanoma, colon, pancreas, cervix, and testis) and three human cultured cell lines (breast cancer, colon cancer, and myeloma) were treated with Catrix, which is a commercially available powdered preparation of bovine (cow) cartilage.[1] Reviewed in [3,4,6] In the study, the growth of all three cultured cell lines and cells from approximately 70% of the tumor specimens were inhibited by 50% or more when Catrix was used at high concentrations (1–5 mg /mL of culture fluid). However, it is unclear whether the inhibitory effect of Catrix in this study was specific to the growth of cancer cells because the preparation’s effect on the growth of normal cells was not tested. In addition, the cytotoxic component of Catrix has not been identified, and it has not been shown that equivalent inhibitory concentrations of this component can be achieved in the bloodstreams of patients who may be treated with either injected or oral formulations of this product. (Refer to the Human/Clinical Studies ¹ section of this summary for more information.)

A commercially available preparation of powdered shark cartilage (no brand name given) was reported to have no effect on the growth of human astrocytoma cells in vitro.[2] The shark cartilage product tested in this study, however, was examined at only one concentration (0.75 mg/mL).[2]

The immune system –stimulating potential of cartilage has also been investigated in laboratory and animal studies.[7] In one study, Catrix was shown to stimulate the production of antibodies by mouse B cells (B lymphocytes) both in vitro and in vivo . However, increased antibody production in vivo was observed only when Catrix was administered by intraperitoneal or intravenous injection. It was not observed when oral formulations of Catrix were used.[7] In most experiments, the proliferation of mouse B cells (i.e., normal, nonmalignant cells) in vitro was increasingly inhibited as the concentration of Catrix was increased (tested concentration range, 1–20 mg/mL). Catrix has also been reported to stimulate the activity of mouse macrophages in vivo, Reviewed in [3,6] but results demonstrating this effect have not been published.

The effects of shark cartilage on the immune system were also reported in two studies that used the same purified protein fraction that had exhibited the most immunostimulatory effects when tested.[8,9] One study explored the effects of this fraction on tumor immune response by observing the infiltration of this fraction on CD4 and CD8 lymphocytes in a murine tumor model. An increase in the ratio of CD4/CD8 lymphocytes was seen in tumor-infiltrating lymphocytes but not in peripheral blood lymphocytes.[9] The second study exploring immune system response measured antibody response, cytotoxic assay, lymphocyte transformation, and intratumor T-cell ratio in mice. The fraction exhibited the ability to augment delayed-type hypersensitivity response against sheep red blood cells in mice and to decrease the cytotoxic activity of natural killer cells. In addition, this fraction showed a strong inhibitory effect on human brain microvascular endothelial cell proliferation and migration in the fibrin matrix.[8]

Additional in vivo studies of the antitumor potential of shark cartilage have been published in the peer-reviewed scientific literature.[10-12] In one study, oral administration of powdered shark cartilage (no brand name given) was shown to inhibit chemically induced angiogenesis in the mesenteric membrane of rats.[10] In another study, oral administration of powdered shark cartilage (no brand name given) was shown to reduce the growth of GS-9L gliosarcomas in rats.[11] It was reported in a third study that oral administration of two powdered shark cartilage products, Sharkilage and MIA Shark Powder, did not inhibit the growth or the metastasis of SCCVII squamous cell carcinomas in mice.[12]

A large number of laboratory and animal studies concerning the antiangiogenic potential of cartilage has been published.[2,10,13-33] Overall, these studies have revealed the presence of at least three angiogenesis inhibitors in bovine cartilage [14,15,18,19,22,24] Reviewed in [17,34] and at least two in shark cartilage.[2,10,26,27]

A liquid (i.e., aqueous) extract of shark cartilage, called AE-941/Neovastat, has also been reported to inhibit the growth of a variety of cancer cell types in vitro. Reviewed in [5] These results have not been published in a peer-reviewed scientific journal and are not consistent with other results obtained by the same group of investigators.[28,35]

Three angiogenesis inhibitors in bovine cartilage have been very well characterized.[14,15,18,19,22,24] Reviewed in [17,34] They are relatively small proteins with molecular masses that range from 23,000 to 28,000.[14,15,24] Reviewed in [17] These proteins, called cartilage-derived inhibitor (CDI), cartilage-derived antitumor factor (CATF), and cartilage-derived collagenase inhibitor (CDCI) by the researchers who purified them,[14,15,22] have been shown to block endothelial cell proliferation in vitro and new blood vessel formation in the chorioallantoic membrane of chicken embryos.[15,18,19,22,24] Reviewed in [17,34] Two of the proteins (CDI and CDCI) have been shown to inhibit matrix metalloproteinase activity in vitro,[14,15,19] Reviewed in [17] and one (CDI) has been shown to inhibit endothelial cell migration in vitro.[15] Reviewed in [17] These proteins do not block the proliferation of normal cells or of tumor cells in vitro.[15,18,22] Reviewed in [17,34] When the amino acid sequences of CDI, CATF, and CDCI were determined, it was discovered that they were the same as those of proteins known otherwise as tissue inhibitor of matrix metalloproteinases 1 (TIMP-1), chondromodulin I, and TIMP-2, respectively.[14,15,19,24] Reviewed in [34]

A possible fourth angiogenesis inhibitor in bovine cartilage has been purified not from cartilage but from the culture fluid of bovine chondrocytes grown in the laboratory.[16] This inhibitor, which has been named chondrocyte-derived inhibitor (ChDI), is a protein that has a molecular mass of approximately 36,000.[16] It has been reported that ChDI and CDI/TIMP-1 have similar antiangiogenic activities,[16] Reviewed in [17,34] but the relationship between these proteins is unclear because amino acid sequence information for ChDI is not available. Thus, whether CDI/TIMP-1 is a breakdown product of ChDI or whether ChDI is truly the fourth angiogenesis inhibitor identified in bovine cartilage is unknown.

As indicated previously, shark cartilage, like bovine cartilage, contains more than one type of angiogenesis inhibitor. One shark cartilage inhibitor, named U-995, reportedly contains two small proteins, one with a molecular mass of approximately 14,000 and the other with a molecular mass of approximately 10,000.[26] Both proteins have shown antiangiogenic activity when tested individually.[26] The exact relationship between these two proteins and their relationship to the larger bovine angiogenesis inhibitors are not known because amino acid sequence information for U-995 is not available. U-995 has been reported to inhibit endothelial cell proliferation, endothelial cell migration, matrix metalloproteinase activity in vitro, and the formation of new blood vessels in the chorioallantoic membrane of chicken embryos.[26] It does not appear to inhibit the proliferation of other types of normal cells or of cancer cells in vitro.[26] Intraperitoneal but not oral administration of U-995 has been shown to inhibit the growth of mouse sarcoma-180 tumors implanted subcutaneously on the backs of mice and the formation of lung metastases of mouse B16-F10 melanoma cells injected into the tail veins of mice.[26]

The second angiogenesis inhibitor identified in shark cartilage appears to have been studied independently by three groups of investigators.[2,27,36] This inhibitor, which was named SCF2 by one of the groups,[36] is a proteoglycan that has a molecular mass of about 10,000. Proteoglycans are combinations of glycosaminoglycans and protein. Reviewed in [31] The principal glycosaminoglycan in SCF2 is keratan sulfate.[36] SCF2 has been shown to block endothelial cell proliferation in vitro,[2,27,36] the formation of new blood vessels in the chorioallantoic membrane of chicken embryos,[2,27] and tumor-induced angiogenesis in the corneas of rabbits.[2,27]

Other studies have demonstrated that AE-941/Neovastat, the previously mentioned aqueous extract of shark cartilage, has antiangiogenic activity,[13,28,29] Reviewed in [35,37-40] but the molecular basis for this activity has not been defined. Therefore, whether AE-941/Neovastat contains U-995 and/or SCF2 or some other angiogenesis inhibitor is not known. It has been reported that AE-941/Neovastat inhibits endothelial cell proliferation and matrix metalloproteinase activity in vitro and the formation of new blood vessels in the chorioallantoic membrane of chicken embryos.[13,28,32] In addition, AE-941/Neovastat has been shown to induce endothelial cell apoptosis by activating caspases, enzymes important in the promotion and regulation of apoptosis.[33] Reviewed in [35,39] It also appears to inhibit the action of vascular endothelial growth factor, thus interfering with the communication between tumor cells and nearby blood vessels.[29] Reviewed in [35,38,39] AE-941/Neovastat may also inhibit angiogenesis through promotion of tissue plasminogen activator (tPA) activity. Neovastat stimulates tPA expression in endothelial cells through an increase in the transcription of the tPA gene.[41] This transcriptional activation is associated with activation of c-Jun N-terminal kinase (JNK) and nuclear factor-kappa B (NF-kappa B) signaling pathways to an extent similar to tumor necrosis factor-alpha (TNF-alpha).[41] Furthermore, AE-941/Neovastat has been reported to inhibit the growth of DA3 mammary adenocarcinoma cells and the metastasis of Lewis lung carcinoma cells in vivo in mice.[28] Reviewed in [5,35,42] In the Lewis lung carcinoma experiments, AE-941/Neovastat enhanced the antimetastatic effect of the chemotherapy drug cisplatin.[28] Reviewed in [5,35,42] All the aspects of preclinical development have been reviewed.[43]

The cartilage-derived antiangiogenic substance troponin I (TnI) has been isolated from human cartilage and has been produced by the cloning and expression of cDNA of human cartilage. It has been shown to specifically inhibit angiogenesis in vivo and in vitro and tumor metastasis in vivo.[44] The active site of Tnl has been located in the amino acid residues of 96 to 116. The synthetic peptide Glu94-Leu123 (pTnl) has been shown to be a potent inhibitor of endothelial cell tube formation and endothelial cell division and to inhibit pancreatic cancer metastases in an in vivo liver metastases model.[45]

References

1. Durie BG, Soehnlen B, Prudden JF: Antitumor activity of bovine cartilage extract (Catrix-S) in the human tumor stem cell assay. J Biol Response Mod 4 (6): 590-5, 1985.  [PUBMED Abstract]
   
   
2. McGuire TR, Kazakoff PW, Hoie EB, et al.: Antiproliferative activity of shark cartilage with and without tumor necrosis factor-alpha in human umbilical vein endothelium. Pharmacotherapy 16 (2): 237-44, 1996 Mar-Apr.  [PUBMED Abstract]
   
   
3. Prudden JF: The treatment of human cancer with agents prepared from bovine cartilage. J Biol Response Mod 4 (6): 551-84, 1985.  [PUBMED Abstract]
   
   
4. Romano CF, Lipton A, Harvey HA, et al.: A phase II study of Catrix-S in solid tumors. J Biol Response Mod 4 (6): 585-9, 1985.  [PUBMED Abstract]
   
   
5. AE 941--Neovastat. Drugs R D 1 (2): 135-6, 1999.  [PUBMED Abstract]
   
   
6. Reviews of Therapies: Biologic/Organic/Pharmacologic Therapies: Cartilage. Houston, Tex: M.D. Anderson Cancer Center, 2003. Available online. ² Last accessed September 16, 2009. 
   
   
7. Rosen J, Sherman WT, Prudden JF, et al.: Immunoregulatory effects of catrix. J Biol Response Mod 7 (5): 498-512, 1988.  [PUBMED Abstract]
   
   
8. Hassan ZM, Feyzi R, Sheikhian A, et al.: Low molecular weight fraction of shark cartilage can modulate immune responses and abolish angiogenesis. Int Immunopharmacol 5 (6): 961-70, 2005.  [PUBMED Abstract]
   
   
9. Feyzi R, Hassan ZM, Mostafaie A: Modulation of CD(4)(+) and CD(8)(+) tumor infiltrating lymphocytes by a fraction isolated from shark cartilage: shark cartilage modulates anti-tumor immunity. Int Immunopharmacol 3 (7): 921-6, 2003.  [PUBMED Abstract]
   
   
10. Davis PF, He Y, Furneaux RH, et al.: Inhibition of angiogenesis by oral ingestion of powdered shark cartilage in a rat model. Microvasc Res 54 (2): 178-82, 1997.  [PUBMED Abstract]
    
    
11. Morris GM, Coderre JA, Micca PL, et al.: Boron neutron capture therapy of the rat 9L gliosarcoma: evaluation of the effects of shark cartilage. Br J Radiol 73 (868): 429-34, 2000.  [PUBMED Abstract]
    
    
12. Horsman MR, Alsner J, Overgaard J: The effect of shark cartilage extracts on the growth and metastatic spread of the SCCVII carcinoma. Acta Oncol 37 (5): 441-5, 1998.  [PUBMED Abstract]
    
    
13. Dupont E, Savard PE, Jourdain C, et al.: Antiangiogenic properties of a novel shark cartilage extract: potential role in the treatment of psoriasis. J Cutan Med Surg 2 (3): 146-52, 1998.  [PUBMED Abstract]
    
    
14. Murray JB, Allison K, Sudhalter J, et al.: Purification and partial amino acid sequence of a bovine cartilage-derived collagenase inhibitor. J Biol Chem 261 (9): 4154-9, 1986.  [PUBMED Abstract]
    
    
15. Moses MA, Sudhalter J, Langer R: Identification of an inhibitor of neovascularization from cartilage. Science 248 (4961): 1408-10, 1990.  [PUBMED Abstract]
    
    
16. Moses MA, Sudhalter J, Langer R: Isolation and characterization of an inhibitor of neovascularization from scapular chondrocytes. J Cell Biol 119 (2): 475-82, 1992.  [PUBMED Abstract]
    
    
17. Moses MA: A cartilage-derived inhibitor of neovascularization and metalloproteinases. Clin Exp Rheumatol 11 (Suppl 8): S67-9, 1993 Mar-Apr.  [PUBMED Abstract]
    
    
18. Takigawa M, Pan HO, Enomoto M, et al.: A clonal human chondrosarcoma cell line produces an anti-angiogenic antitumor factor. Anticancer Res 10 (2A): 311-5, 1990 Mar-Apr.  [PUBMED Abstract]
    
    
19. Ohba Y, Goto Y, Kimura Y, et al.: Purification of an angiogenesis inhibitor from culture medium conditioned by a human chondrosarcoma-derived chondrocytic cell line, HCS-2/8. Biochim Biophys Acta 1245 (1): 1-8, 1995.  [PUBMED Abstract]
    
    
20. Langer R, Brem H, Falterman K, et al.: Isolations of a cartilage factor that inhibits tumor neovascularization. Science 193 (4247): 70-2, 1976.  [PUBMED Abstract]
    
    
21. Langer R, Conn H, Vacanti J, et al.: Control of tumor growth in animals by infusion of an angiogenesis inhibitor. Proc Natl Acad Sci U S A 77 (7): 4331-5, 1980.  [PUBMED Abstract]
    
    
22. Takigawa M, Shirai E, Enomoto M, et al.: Cartilage-derived anti-tumor factor (CATF) inhibits the proliferation of endothelial cells in culture. Cell Biol Int Rep 9 (7): 619-25, 1985.  [PUBMED Abstract]
    
    
23. Takigawa M, Shirai E, Enomoto M, et al.: A factor in conditioned medium of rabbit costal chondrocytes inhibits the proliferation of cultured endothelial cells and angiogenesis induced by B16 melanoma: its relation with cartilage-derived anti-tumor factor (CATF). Biochem Int 14 (2): 357-63, 1987.  [PUBMED Abstract]
    
    
24. Hiraki Y, Inoue H, Iyama K, et al.: Identification of chondromodulin I as a novel endothelial cell growth inhibitor. Purification and its localization in the avascular zone of epiphyseal cartilage. J Biol Chem 272 (51): 32419-26, 1997.  [PUBMED Abstract]
    
    
25. Lee A, Langer R: Shark cartilage contains inhibitors of tumor angiogenesis. Science 221 (4616): 1185-7, 1983.  [PUBMED Abstract]
    
    
26. Sheu JR, Fu CC, Tsai ML, et al.: Effect of U-995, a potent shark cartilage-derived angiogenesis inhibitor, on anti-angiogenesis and anti-tumor activities. Anticancer Res 18 (6A): 4435-41, 1998 Nov-Dec.  [PUBMED Abstract]
    
    
27. Oikawa T, Ashino-Fuse H, Shimamura M, et al.: A novel angiogenic inhibitor derived from Japanese shark cartilage (I). Extraction and estimation of inhibitory activities toward tumor and embryonic angiogenesis. Cancer Lett 51 (3): 181-6, 1990.  [PUBMED Abstract]
    
    
28. Dupont E, Falardeau P, Mousa SA, et al.: Antiangiogenic and antimetastatic properties of Neovastat (AE-941), an orally active extract derived from cartilage tissue. Clin Exp Metastasis 19 (2): 145-53, 2002.  [PUBMED Abstract]
    
    
29. Béliveau R, Gingras D, Kruger EA, et al.: The antiangiogenic agent neovastat (AE-941) inhibits vascular endothelial growth factor-mediated biological effects. Clin Cancer Res 8 (4): 1242-50, 2002.  [PUBMED Abstract]
    
    
30. Cho J, Kim Y: Sharks: a potential source of antiangiogenic factors and tumor treatments. Mar Biotechnol (NY) 4 (6): 521-5, 2002.  [PUBMED Abstract]
    
    
31. Alberts B, Bray D, Lewis J, et al.: Molecular Biology of the Cell. 3rd ed. New York, NY: Garland Publishing, 1994. 
    
    
32. Gingras D, Renaud A, Mousseau N, et al.: Matrix proteinase inhibition by AE-941, a multifunctional antiangiogenic compound. Anticancer Res 21 (1A): 145-55, 2001 Jan-Feb.  [PUBMED Abstract]
    
    
33. Boivin D, Gendron S, Beaulieu E, et al.: The antiangiogenic agent Neovastat (AE-941) induces endothelial cell apoptosis. Mol Cancer Ther 1 (10): 795-802, 2002.  [PUBMED Abstract]
    
    
34. Suzuki F: Cartilage-derived growth factor and antitumor factor: past, present, and future studies. Biochem Biophys Res Commun 259 (1): 1-7, 1999.  [PUBMED Abstract]
    
    
35. Falardeau P, Champagne P, Poyet P, et al.: Neovastat, a naturally occurring multifunctional antiangiogenic drug, in phase III clinical trials. Semin Oncol 28 (6): 620-5, 2001.  [PUBMED Abstract]
    
    
36. Liang JH, Wong KP: The characterization of angiogenesis inhibitor from shark cartilage. Adv Exp Med Biol 476: 209-23, 2000.  [PUBMED Abstract]
    
    
37. Bukowski RM: AE-941, a multifunctional antiangiogenic compound: trials in renal cell carcinoma. Expert Opin Investig Drugs 12 (8): 1403-11, 2003.  [PUBMED Abstract]
    
    
38. Gingras D, Batist G, Béliveau R: AE-941 (Neovastat): a novel multifunctional antiangiogenic compound. Expert Rev Anticancer Ther 1 (3): 341-7, 2001.  [PUBMED Abstract]
    
    
39. Gingras D, Boivin D, Deckers C, et al.: Neovastat--a novel antiangiogenic drug for cancer therapy. Anticancer Drugs 14 (2): 91-6, 2003.  [PUBMED Abstract]
    
    
40. Ryoo JJ, Cole CE, Anderson KC: Novel therapies for multiple myeloma. Blood Rev 16 (3): 167-74, 2002.  [PUBMED Abstract]
    
    
41. Gingras D, Nyalendo C, Di Tomasso G, et al.: Activation of tissue plasminogen activator gene transcription by Neovastat, a multifunctional antiangiogenic agent. Biochem Biophys Res Commun 320 (1): 205-12, 2004.  [PUBMED Abstract]
    
    
42. Wojtowicz-Praga S: Clinical potential of matrix metalloprotease inhibitors. Drugs R D 1 (2): 117-29, 1999.  [PUBMED Abstract]
    
    
43. Dredge K: AE-941 (AEterna). Curr Opin Investig Drugs 5 (6): 668-77, 2004.  [PUBMED Abstract]
    
    
44. Moses MA, Wiederschain D, Wu I, et al.: Troponin I is present in human cartilage and inhibits angiogenesis. Proc Natl Acad Sci U S A 96 (6): 2645-50, 1999.  [PUBMED Abstract]
    
    
45. Kern BE, Balcom JH, Antoniu BA, et al.: Troponin I peptide (Glu94-Leu123), a cartilage-derived angiogenesis inhibitor: in vitro and in vivo effects on human endothelial cells and on pancreatic cancer. J Gastrointest Surg 7 (8): 961-8; discussion 969, 2003.  [PUBMED Abstract]
    
    

Glossary Terms

Cancer that begins in cells that line certain internal organs and that have gland-like (secretory) properties.

The arrangement of amino acids in a protein. Proteins can be made from 20 different kinds of amino acids, and the structure and function of each protein are determined by the kinds of amino acids used to make it and how they are arranged.

A substance that may prevent the formation of blood vessels. In anticancer therapy, an angiogenesis inhibitor may prevent the growth of new blood vessels that tumors need to grow.

Having to do with reducing the growth of new blood vessels.

A protein made by plasma cells (a type of white blood cell) in response to an antigen (a substance that causes the body to make a specific immune response). Each antibody can bind to only one specific antigen. The purpose of this binding is to help destroy the antigen. Some antibodies destroy antigens directly. Others make it easier for white blood cells to destroy the antigen.

Having to do with stopping abnormal cell growth.

A type of cell death in which a series of molecular steps in a cell leads to its death. This is the body’s normal way of getting rid of unneeded or abnormal cells. The process of apoptosis may be blocked in cancer cells. Also called programmed cell death.

Having to do with water.

A tumor that begins in the brain or spinal cord in small, star-shaped cells called astrocytes.

A type of immune cell that makes proteins called antibodies, which bind to microorganisms and other foreign substances, and help fight infections. A B cell is a type of white blood cell. Also called B lymphocyte.

A tube through which the blood circulates in the body. Blood vessels include a network of arteries, arterioles, capillaries, venules, and veins.

Glandular organ located on the chest. The breast is made up of connective tissue, fat, and breast tissue that contains the glands that can make milk. Also called mammary gland.

Cancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare.

A term for diseases in which abnormal cells divide without control and can invade nearby tissues. Cancer cells can also spread to other parts of the body through the blood and lymph systems. There are several main types of cancer. Carcinoma is a cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is a cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is a cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood. Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system. Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord. Also called malignancy.

Cancer that begins in the skin or in tissues that line or cover internal organs.

A tough, flexible tissue that lines joints and gives structure to the nose, ears, larynx, and other parts of the body.

The individual unit that makes up the tissues of the body. All living things are made up of one or more cells.

The lower, narrow end of the uterus that forms a canal between the uterus and vagina.

Treatment with drugs that kill cancer cells.

Cartilage cell. Chondrocytes make the structural components of cartilage.

The membrane in hens' eggs that helps chicken embryos get enough oxygen and calcium for development. The calcium comes from the egg shell.

A drug used to treat many types of cancer. Cisplatin contains the metal platinum. It kills cancer cells by damaging their DNA and stopping them from dividing. Cisplatin is a type of alkylating agent. Also called Platinol.

A type of enzyme that breaks down the protein collagen.

The longest part of the large intestine, which is a tube-like organ connected to the small intestine at one end and the anus at the other. The colon removes water and some nutrients and electrolytes from partially digested food. The remaining material, solid waste called stool, moves through the colon to the rectum and leaves the body through the anus.

Cancer that forms in the tissues of the colon (the longest part of the large intestine). Most colon cancers are adenocarcinomas (cancers that begin in cells that make and release mucus and other fluids).

The transparent part of the eye that covers the iris and the pupil and allows light to enter the inside.

Cells of a single type (human, animal, or plant) that have been adapted to grow continuously in the laboratory and are used in research.

Cell-killing.

Early stage in the development of a plant or an animal. In vertebrate animals (have a backbone or spinal column), this stage lasts from shortly after fertilization until all major body parts appear. In particular, in humans, this stage lasts from about 2 weeks after fertilization until the end of the seventh or eighth week of pregnancy.

The main type of cell found in the inside lining of blood vessels, lymph vessels, and the heart.

A protein that speeds up chemical reactions in the body.

A type of glioma (cancer of the brain that comes from glial, or supportive, cells).

A type of long, unbranched polysaccharide molecule. Glycosaminoglycans are major structural components of cartilage and are also found in the cornea of the eye.

The complex group of organs and cells that defends the body against infections and other diseases.

In the laboratory (outside the body). The opposite of in vivo (in the body).

In the body. The opposite of in vitro (outside the body or in the laboratory).

Use of a syringe and needle to push fluids or drugs into the body; often called a "shot."

Within the peritoneal cavity (the area that contains the abdominal organs). Also called IP.

Into or within a vein. Intravenous usually refers to a way of giving a drug or other substance through a needle or tube inserted into a vein. Also called IV.

A researcher in a clinical trial or clinical study.

A glycosaminoglycan (a type of polysaccharide) found in cartilage and in the cornea of the eye.

Research done in a laboratory. These studies may use test tubes or animals to find out if a drug, procedure, or treatment is likely to be useful. Laboratory studies take place before any testing is done in humans.

One of a pair of organs in the chest that supplies the body with oxygen, and removes carbon dioxide from the body.

Cancer that has spread from the original (primary) tumor to the lung.

A type of immune cell that is made in the bone marrow and is found in the blood and in lymph tissue. The two main types of lymphocytes are B lymphocytes and T lymphocytes. B lymphocytes make antibodies, and T lymphocytes help kill tumor cells and help control immune responses. A lymphocyte is a type of white blood cell.

A type of white blood cell that surrounds and kills microorganisms, removes dead cells, and stimulates the action of other immune system cells.

Having to do with the breast.

A member of a group of enzymes that can break down proteins, such as collagen, that are normally found in the spaces between cells in tissues (i.e., extracellular matrix proteins). Because these enzymes need zinc or calcium atoms to work properly, they are called metalloproteinases. Matrix metalloproteinases are involved in wound healing, angiogenesis, and tumor cell metastasis.

A form of cancer that begins in melanocytes (cells that make the pigment melanin). It may begin in a mole (skin melanoma), but can also begin in other pigmented tissues, such as in the eye or in the intestines.

The peritoneal membrane that attaches the intestines to the abdominal wall near the back.

The spread of cancer from one part of the body to another. A tumor formed by cells that have spread is called a “metastatic tumor” or a “metastasis.” The metastatic tumor contains cells that are like those in the original (primary) tumor. The plural form of metastasis is metastases (meh-TAS-tuh-SEEZ).

Having to do with metastasis, which is the spread of cancer from the primary site (place where it started) to other places in the body.

A measure of weight. A milligram is approximately 450,000 times smaller than a pound and 28,000 times smaller than an ounce.

A measure of volume in the metric system. One thousand milliliters equal one liter. Also called cc, cubic centimeter, and ml.

The sum of the atomic masses of all atoms in a molecule, based on a scale in which the atomic masses of hydrogen, carbon, nitrogen, and oxygen are 1, 12, 14, and 16, respectively. For example, the molecular mass of water, which has two atoms of hydrogen and one atom of oxygen, is 18 (i.e., 2 + 16).

Cancer that arises in plasma cells, a type of white blood cell.

Not cancerous. Nonmalignant tumors may grow larger but do not spread to other parts of the body. Also called benign.

By or having to do with the mouth.

One of a pair of female reproductive glands in which the ova, or eggs, are formed. The ovaries are located in the pelvis, one on each side of the uterus.

A glandular organ located in the abdomen. It makes pancreatic juices, which contain enzymes that aid in digestion, and it produces several hormones, including insulin. The pancreas is surrounded by the stomach, intestines, and other organs.

Research using animals to find out if a drug, procedure, or treatment is likely to be useful. Preclinical studies take place before any testing in humans is done.

A molecule made up of amino acids that are needed for the body to function properly. Proteins are the basis of body structures such as skin and hair and of substances such as enzymes, cytokines, and antibodies.

A molecule that contains both protein and glycosaminoglycans, which are a type of polysaccharide. Proteoglycans are found in cartilage and other connective tissues.

A cancer of the bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue.

Cancer that begins in squamous cells, which are thin, flat cells that look like fish scales. Squamous cells are found in the tissue that forms the surface of the skin, the lining of the hollow organs of the body, and the passages of the respiratory and digestive tracts. Also called epidermoid carcinoma.

Beneath the skin.

One of two egg-shaped glands inside the scrotum that produce sperm and male hormones. Also called testicle.

An abnormal mass of tissue that results when cells divide more than they should or do not die when they should. Tumors may be benign (not cancer), or malignant (cancer). Also called neoplasm.

A substance made by cells that stimulates new blood vessel formation. Also called VEGF.