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The demise of cells by programmed cell death referred to as apoptosis, a Greek word that means 'dropping off' or 'falling off' as in leaves from a tree, has been recently a topic of intense interest in biomedical sciences. Apoptosis is a well-defined sequence of morphological changes of cells that shrink and condense and then fragment, releasing small membrane-bound apoptotic bodies, which are phagocytosed by other cells. Importantly, the intracellular constituents are not released into the extracellular milieu where they might have deleterious effects on neighboring cells. On the contrary, cells that die in response to tissue damage or other reasons exhibit very different morphological changes generally called necrosis. The cells that undergo this process swell and burst, releasing their intracellular contents, which can damage surrounding cells and often cause inflammation.
Apoptosis refers to a particular morphology in which a chromatin condenses or coalesces to a heterochromatin in one or more masses in the nucleus. It usually settles along still-intact nuclear membrane referred to as margination of the chromatin. One of the essential functions of apoptosis is the elimination of cells in which DNA damages, faulty proliferation or improper adhesion to extracellular matrix that cannot be repaired. In cancer cells, the mechanism of apoptosis induction is broken. Therefore, more and more ideas and hypotheses for selective inducing apoptosis in cancer cells are tested in a growing number of laboratories all over the world.
The subject of programmed cell death has been recently discussed in almost 80 000 publications. As it is known, cell apoptosis may be induced by various stress factors (e.g. hypoxia, expression of oncogenes, mutations, DNA damages). On the other hand, apoptosis may be induced via internal or external signals, for instance proteins. Some of such endogenous and exogenous proapoptotic proteins have been found and described. Their genes may be used in modern anticancer therapies.
For example, introducing into cancer cells proapoptotic genes as Bax, Bcl-X5 or E2F-1 significantly increases induction of apoptosis. Some clinical trials concern therapeutic application of a 121-amino acids apoptin originated from chicken anemia virus (CAV). Recent data suggest that apoptosis induced by this protein involves caspases, a family of cysteinyl aspartate-specific proteinases. In vitro results show that apoptin is very active against cancer cells without inducing toxicity to normal cells. This tumor-specific effect may be explained by the nuclear localization of the protein in tumor cells required for its action. Moreover, apoptin is equally active, such as p53-mutant, Bcl-2-overexpressing or BCR-ABL-expressing tumor cells.
Other investigations showed that E4orf4 induces apoptosis in cancer cells by linking with 2A (PP2A) phosphatase. Unfortunately, induction of apoptosis by introducing genes encoding proapoptotic proteins has been little known. One possible mechanism is associated with destruction of mitochondrial membranes and, in consequence, disturbing electrons transport, oxidative phosphorylation and ATP synthesis. Finally, the cell dies but the death is slightly different than that during typical apoptosis induced by caspases due to prolonged time of this process. Proapoptotic proteins cannot be directly introduced to cancer cells because there are no specific receptors. They are transported through membranes in complexes by special fusion proteins called ligands.
Other method is introducing them as genes by vectors and this approach has been already successfully applied. Clinical trials are presently underway to test efficiency of new apoptosis-triggering drugs. A large number of adenoviral agents are being constructed, including replication-incompetent and replication-selective oncolytic adenoviruses. One of them is ONYX-015, a replication-competent virus genetically engineered to selectively replicate in and lyse p53-deficient cancer cells. Other agent, INGN 201, was shown to deliver a p53 expression. Preclinical studies in human cell lines and animals with head and neck cancers have shown that the p53 gene is transcribed and translated into p53 protein. Respectively, 5% and 58% of patients receiving three intratumoral injections of INGN 201 in conjunction with radiation therapy for over 6 weeks were shown to have achieved complete and partial responses. Other example may be a gene encoding the proapoptotic Vpr protein that was successfully transferred into cancer cells by the HIV-1 virion. These agents are introduced by intravascular infusion or intratumoral or epitumoral injections. An example of a target therapy against cancer is an intravenous administration of liposomal form of tretinoin (ATRA). Treatment of acute promyelocytic leukemia (APL) with ATRA alone or in combination with chemotherapy results in an almost complete remission rate as high as 85% to 95%.
Other proapoptotic anticancer therapeutics is Genasense developed by the Genta Company. Genasense is a phosphothioate oligonucleotide consisting of 18 modified DNA bases. First, the single-stranded DNA molecule must be incorporated into a cancer cell and then target the mRNA by having a complementary sequence to it. This drug inhibits the production of a protein known as Bcl-2 that is widely expressed in many types of cancer. This up-regulation of Bcl-2 blocks the release of cytochrome C from the mitochondria thereby preventing apoptosis. Furthermore, Bcl-2 appears to be a major contributor to both inherent and acquired resistance to current anticancer treatments. By inhibiting production of Bcl-2, Genasense enables the cancer cells to be killed by apoptosis when treated with current state of the art therapy. Interesting apoptosis-inducing drug is Velcade jointly developed by NCI and Millenium Pharmaceuticals. Activity of Velcade is mainly associated with reversible inhibition of the proteasome and building up many proteins including BAX. In the normal cells, the BAX protein induces apoptosis by blocking the activity of Bcl-2. When BAX level increases, BAX inhibition of Bcl-2 also increases and the cells undergo apoptosis. Non-clinical studies have demonstrated that cancer cells are more sensitive to the effects of the proteasome inhibition than normal cells.
Tamm, I., Dorken, B., Hartmann G., 2001. Antisense therapy in oncology: new hope for an old idea? Lancet 358, 489-197.
Tamm, I., Schriever, F., Dorken, B., 2001. Apoptosis: implications of basic research for clinical oncology. Lancet Oncology 2, 33-42.
Information concerning diagnostic methods, treatment options and even the pathophysiological characteristics of this condition has been provided in useful details by researchers, but the specific causes of prostate cancer remain unknown up to this day.
The background to the launch of Vaniqa is intriguing: A drug by the name of Eflornithine was developed many years ago to combat malignant cancer. Theres no known way of preventing prostate cancer, although some studies have indicated that taking 200 micrograms of selenium every day may reduce your risk of developing the cancer.
The October issue of the Mayo Clinic Proceedings (reference date October 11, 2004) had researchers report that: The antidepressant (Celexa) is an effective medication that reduces the hot flashes of men who are undergoing hormone therapy for prostate cancer the Paxil, or Paroxetine compound found in Celexa seems to be responsible for diminishing these hot flushes, the researchers have reported.
They are called cancers because they keep on growing through everything around them until they are completely removed. Antioxidants are what help to protect our bodies from damage by free radicals and reduce the risk of cancer, particularly gastric, esophageal, skin and ovarian.
Many anti-cancer drugs are being tried to treat DMM, with varying levels of short-term success. Radiotherapy can work by destroying cancer cells through radiation.
The following diseases have been associated with exposure to oil mist: skin - oil acne, contact dermatitis, and photosensitive allergic dermatitis; respiratory system - rhinitis, bronchitis, bronchial asthma, lipoid pneumonia, lung fibrosis and lung cancer; scrotum - benign and malignant tumours.
If the user is a smoker AND consumes alcohol, heavy use of mouthwash can even cause certain cancers. Even the drugs taken to treat cancer and AIDS may cause a neuropathy. Post-surgery chemotherapy is generally needed to eliminate residual cancer and prevent relapse.
The chances of a patients survival depend largely on how early and how aggressively the cancer is treated. This is also known as the macroscopic description of the cancer tissue. In most people affected by cancer, these genetic changes happen after birth later in life.
Measures levels of Prostate-Specific Antigen a key prostate cancer marker, the cancer may eat up the lungs, wind-pipes, ribs and adjacent muscles. Basal cell skin cancers fall apart and feel like marshmallows when they are scraped.
There is evidence, for example, that coffee reduces the risk for colon cancer if consumed at the rate of four cups a day -- not the most salutary effect you can cite considering that intake at such an amount can easily lead to greater ills.
Though mesothelioma is a permanent cancer disease and the survival rate is very low, timely identification and perfect treatment at the right time could able to help us survive some long time. This is often the best form of treatment for late stage prostate cancer.
If your doctor tells you for example that you have cancer it is unlikely that you will meet this news with calm acceptance. Is there a way for you to diagnose it yourself, by noting if prostate cancer symptoms appear?
As the evidence develops, more physicians are beginning to recommend steps to take to increase the bodys ability to fight off cancer before it can get a foot holding colon cancer - by surgery, radiation therapy and by chemotherapy.
Lentils are an important cancer fighting food for ABs. Chemotherapy treatment for cancer and a variety of medications for other serious diseases can of course result in hair loss which might be temporary or in some cases permanent. By using a sunless tanning lotion you can avoid the skin cancer risk that comes from the suns UV rays.
Accelerated Aging, Cancers, Heart Disease, Arthritis, Autoimmune Disorders, Alzheimers, Cataracts, Etc. Making black tea a habit can provide a protective effect against heart disease, cancer, and stress-related illness. Well, it is important to stress that an enlarged prostate does not necessarily scream prostate cancer.
In many ways prostate cancer cells are just like any other cells of the body and will go through various stages of growth and there are a number of tests which can be performed, and grading systems which can be used, to determine and classify the stage of growth of prostate cancer cells.
Nationality studies have shown that certain racial groups such as European and African women tend to have higher risk of breast cancer compared to Asian women. Cancer that begins in the skin or in tissues that line or cover internal organs is carcinoma.
Both Radoslaw Pilarski & Ben Needles are contributors for EditorialToday. The above articles have been edited for relevancy and timeliness. All write-ups, reviews, tips and guides published by EditorialToday.com and its partners or affiliates are for informational purposes only. They should not be used for any legal or any other type of advice. We do not endorse any author, contributor, writer or article posted by our team.
Radoslaw Pilarski has sinced written about articles on various topics from Allergies, Types of Cancer and Pets. Radoslaw Pilarski is a PhD candidate working on anticancer properties of Uncaria tomentosa - - at Institute of Bioorganic Chemistry. Radoslaw Pilarski's top article generates over 4400 views. to your Favourites.
Ben Needles has sinced written about articles on various topics from Business Credit Cards, Anger Control and Business Credit Cards. About the Author (text)Uchenna Ani-Okoye is an internet marketing advisor and co founder of . Ben Needles's top article generates over 550000 views. to your Favourites.