Cancer Herpes virus

The most widely studied therapeutic proteins produced in plants include monoclonal antibodies for passive immunotherapy and antigens for use as oral vaccines [40]. Antibodies against dental caries, rheumatoid arthritis, cholera, E. coli diarrhea, malaria, certain cancers, Norwalk virus, HIV, rhinovirus, influenza, hepatitis B virus and herpes simplex virus have been produced in transgenic plants. However, the anti-Streptococcus mutans secretory antibody for the prevention of dental caries is the only plant-derived antibody currently in Phase II clinical trials [40]. Until recently, most antibodies were expressed in tobacco, potato, alfalfa, soybean, rice and wheat [9], It has been estimated that for every 170 tons of harvested tobacco, 100 tons represents harvested leaves. A single hectare could thus yield 50 kg of secretory IgA [3, 41]. Furthermore, it has been estimated that the cost of antibody production in plants is half that in transgenic animals and 20 times lower than in mammalian cell cul-... 

Hairy Leukoplakia. This is an abnormal condition of the mouth in which white plaques appear on the surfaces of the tongue. These plaques are not due to the overgrowth of a fungus or bacterium. They are due to the abnormal growth of the papillae cells of the tongue. These plaques cannot be scraped off they resemble cancer cells and appear as a result of infection with Epstein-Barr virus, which is a member of the herpes virus family. 

Their DNA is also integrated into the host genome. Some viruses that usually produce lysis of cells, e.g., SV40, adenoviruses, herpes viruses, and hepatitis B virus, can occasionally be integrated into the DNA of the host. If such integration occurs in the middle of a gene, that gene will be mutated. This is one way in which such viruses may induce cancers. 

Numerous transcriptionally targeted replication-competent adenovimses and herpes viruses have been shown to be highly specific (up to 10,000-fold relative to nontarget cells) in cell culture experiments. In addition, animal models have demonstrated their safety and efficacy. It thus appears that the transcriptional targeting of viral replication holds some promise as a strategy for cancer gene therapy. 

Some phenylalanine-derived monocyclic azetidin-2-ones, for example, 564, have been reported as modest inhibitors of human cytomegalovirus (HCMV) serine protease <2004BML2253>. HCMV is a ubiquitous member of the herpes virus family. Severe manisfestations of HCMV can be seen in individuals with a weakened immune system due to late-stage cancer and AIDS, or by immunosuppressive therapy following organ transplantation. 

Vaccine development is hampered by the fact that recurrent disease is common. Thus, natural infection does not provide immunity and the best method to induce immunity artificially is not clear. The genome of these viruses is also able to cause transformation of normal cells, thus conferring on them one of the properties attributed to cancerous cells. Vaccine made from herpes viruses must, therefore, be carefully purified and screened to eliminate the possibility of including any active genetic material. 

Viral, parasitic, and bacterial infections have been linked to cancer (Table 9). DNA viruses such as Epstein-Barr, hepatitis B, hepatitis C, papillomaviruses, and Kaposi sarcoma herpes virus and RNA viruses such as human T-cell leukemia virus type I and human immunodeficiency virus have been implicated in causing cancer in humans and are listed as known-to-cause-cancer in humans by the International Agency for Research on Cancer (lARC). In man, the liver fluke, Opisthorchis viverrini, is associated with the development of cholangiocarcinomas of the liver and the blood fluke. Schistosoma haematobium, with carcinoma of the urinary bladder. There is evidence that chronic Helicobacter pylori infection of the stomach in man is not only related to... 

In the area of classical antimetabolites, a host of highly active new nucleosides have been found that show promise in the chemotherapy of cancer and viral diseases. Classical antimetabolites appear to have a virtual monopoly in the field of antiviral agents. After the discovery of the first effective drugs against,the Herpes virus 28b, c 25), a new breakthrough may have been... 

Epidemiological evidence points to a connection between long-term inflammation and the development of cancer that is characterized by dysplasia, hyperplasia, and sometimes irreversible cancer transformations. Nearly 15% of worldwide cancer incidence in humans is associated with microbial infection (Kuper et al. 2002). Chronic infections, with human papilloma virus or with hepatitis B or C viruses in immunocompetent human hosts, can lead to cervical and hepatocellular carcinomas, respectively. Infection with the human herpes virus can produce Kaposi s sarcoma in the skin. Karposi s cancers are seen more often in the IDS-compromised AIDS patients. After protracted inflammation, Helicobacter pylori can cause stomach irrita-... 

Viruses have been implicated in the development of at least two cancers. Infection with the human papilloma virus is a major risk factor for cervical cancer, and like any sexually transmitted disease, the cancer is more common amongst those who have had numerous partners and is almost unknown in nuns. But the most well-established link is between Burkitt s lymphoma and the Epstein-Barr virus (one of the herpes viruses) in African countries. In developed countries, this virus causes glandular fever (infectious mononucleosis), and the different progress of the disease in Africans is apparently due to an immune system that is usually suppressed through a long-term assault by malaria parasites like Plasmodium falciparum. 

Questions have been raised about the possible health benefits and risks posed by BHA and BHT. On the one hand, these compounds may contribute to good health by destroying substances in the body that can lead to cancer. They may also destroy the herpes virus and the human immunodeficiency virus (HIV). Most nutritionists agree that antioxidants can be helpful in protecting cells and tissues from aging and damage by oxygen. 

Sodhi A. The Kaposi s sarcoma-associated herpes virus G protein-coupled receptor up-regulates vascular endothelial growth factor expression and secretion through mitogen-activated protein kinase and p38 pathways acting on hypoxia-inducible factor lalpha. Cancer Res 2000 60(l7) 4873-80. 

Vidarabine 4.16) differs from adenosine in the same way that cytarabine differs from cytidine, namely the natural sugar has been replaced by arabinose. However, the anti-viral properties of vidarabine are more to the fore than any anti-cancer power, the exact opposite of cytarabine s properties. Vidarabine, also known as Ara A, is 9-j8-D-arabinofuranosyladenine and it has a reasonably high therapeutic index (Muller et al., 1977). Its most successful and spectacular application has been in herpes virus encephalitis, of which several thousands of cases break out in the United States each year, killing 70% of the sufferers... 

Nowadays, it is estimated that approximately 20 % of all cancers worldwide are associated with infections. First and foremost, a number of different viruses are of importance like the Epstein-Barr virus (Burkitt lymphoma, naso-pharyn-geal cancer), the human herpes virus type 8, the human papilloma virus, the hepatitis-B- and -C-viruses, and above all, the human immunodeficiency virus (Kaposi sarcoma). The bacterium Helicobacter pylori is the leading contributor to stomach cancer. Parasites, like the flatworm Schistosoma haematobium (the cause of biUiarzia or snail fever) lead in Egypt to an increased incidence of bladder cancer, and types of liver flukes Opisthorchis viverrini, Clonorchis sinensis) are important risk factors, particularly in south-east Thailand and in southern China, for the appearance of Cholangio carcinoma and hepatocellular carcinoma. [296]... 

Although infection by EBV can cause infectious mononucleosis and can lead to EBV-associated cancers, notably Burkitt s lymphoma and nasopharyngeal carcinoma in restricted geographic regions, most humans are infected by the virus without symptoms. Latent infection is believed to involve both epithelial cells of the oropharynx and B lymphocytes, and, as with other herpes viruses, is presumed to last lifelong (see ref. 2 for a review). 

Tjuvajev JG, Finn R, Watanabe K, Joshi R, Oku T, Kennedy J, Beattie B, Koutcher J, Larson S, Blasberg RG. Noninvasive imaging of herpes virus thymidine kinase gene transfer and expression a potential method for monitoring clinical gene therapy. Cancer Res 1996 56 4087-4095. 

---