Overturning a century of prevailing thought, scientists are finding that neurons in the adult brain can remodel their connections. In work reported in the Nov. 24 online edition of the Proceedings of the National Academy of Sciences (PNAS) , Elly Nedivi, associate professor of neurobiology at the Picower Institute for Learning and Memory, and colleagues
Full Post: Neurons in adult brain can remodel their connections
The last few years have witnessed remarkable progress in understanding the biologic and biochemical bases for cancer. This is not to imply that the problem of neoplastic disease is solved. Gains in the treatment of cancer in adults have been gradual and have focused upon those malignancies characterized by unusual sensitivity to radiation and chemotherapy. These include primarily acute myelocytic leukemia, the lymphoproliferative malignancies, testicular cancer, and breast cancer. New treatment modalities involving immunotherapy and agents that promote normal cell maturation remain experimental and are under intensive investigation. Meanwhile, the search has begun for compounds which can interact with oncogene products, gene regulators, and growth factors and their receptors. Research employing modern technology in molecular genetics and immunology promises to provide a new array of anticancer agents which could move rapidly into clinical trials. This is possible because understanding cancer as a pathologic process is buttressed by new knowledge of cancer as an acquired genetic derangement.
This chapter provides an overview of the biology, etiology, and clinical sequelae of the neoplastic process, followed by a description of the general methods for diagnosing cancer and determining its stage, or extent of spread. Cancer treatment is presented in the following chapter, and the details of managing patients with specific types of malignant disease will be found in the chapters devoted to disorders of various specific organs.
Definition The terms cancer, neoplasia, and malignancy are usually used interchangeably in both the technical and popular literature. The disease called cancer is best defined by four characteristics which describe how cancer cells act differently from their normal counterparts.
1 Clonality: In most cases, cancer originates from a single stem cell which proliferates to form a clone of malignant cells.
2 Autonomy: Growth is not properly regulated by the normal biochemical and physical influences in the environment.
3 Anaplasia: There is a lack of normal, coordinated cell differentiation.
4 Metastasis: Cancer cells develop the capacity for discontinuous growth and dissemination to other parts of the body.
Properties similar to each of these characteristics can be expressed by normal, nonmalignant cells at certain appropriate times—for example, during embryogenesis and wound repair—but in cancer cells the characteristic is inappropriate or excessive. The process by which a normal cell is converted into one which exhibits these characteristic traits is termed malignant transformation.
German scientist Otto H. Warburg’s theory on the origin of cancer earned him the Nobel Prize in 1931, but the biochemical basis for his theory remained elusive. His theory that cancer starts from irreversible injury to cellular respiration eventually fell out of favor amid research pointing to genomic mutations as the cause of uncontrolled cell
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Researchers from Virginia Commonwealth University have identified a new anti-tumor gene called SARI that can interact with and suppress a key protein that is overexpressed in 90 percent of human cancers. The discovery could one day lead to an effective gene therapy for cancer. According to Paul B. Fisher, M.Ph., Ph.D., professor and chair of
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Scientists have revealed for the first time that cancer cells can reverse a process which irrevocably commits normal cells to die, in a study published in the British Journal of Cancer. Researchers at The Chinese University of Hong Kong treated human cervical, skin, liver and breast cancer cells each with three different chemicals which initiate
Full Post: Cancer cells pull off ‘Houdini’ escape to evade chemotherapy
Human calmodulin-like protein (CLP) is found in many cell types including breast, thyroid, prostate, kidney, and skin. The protein can regulate many cell activities and has a highly specific expression. Gaining an understanding about the expression of CLP in oral epithelial cells and its possible downregulation (or lack of production) in cancer may be a
Full Post: Lack of human calmodulin-like protein can be indicative of oral cancer
In breast tissue, cells lining the breast’s ducts have a certain shape that is required to maintain both organ structure and function. All breast cancers display a loss of this characteristic organization, but very little is known about the molecules and pathways that regulate tissue structure and the role they play during cancer. A team
Full Post: Scribble protein found to be an important regulator of breast cancer