Cancer formation process

These phytochemical anticancer supplements can be categorized broadly into three groups, based on where they interrupt the cancer formation process ... 

Cancer is a dangerous disease which is one of the leading causes of death in the modem society [28]. Cancer formation process is very complex. Generally, oxidative stress has been proven to be one of the main factors that lead to the formation of cancer [29]. Large quantum of research that has been carried out in this field during the past two decades leads to the conclusion that excessive oxidative stress in the body for extended periods of time activates inflammatory pathways which cause the transformation of normal cells into cancer cells, supports the survival of cancer cells, and finally leads to cancer cell proliferation [16-18,26,29-31]. 

Although much is known about the processes of cancer formation, or carcinogenesis, comparatively little is known about the processes of cancer regression. The former will be explored as an introduction to the latter, and both involve the biological and chemical functions of the body, stated in terms of normal cells vs. cancerous ones. Surgical excision and radiation treatment are excluded from the discussion, though they can be selective if, say, the solid tumor is localized and has not yet spread or metastasized — and if the operations or treatments in themselves do not cause metastasis. 

Recent literature supports that inflammatory cells can be activated by oxidative stress, thereby causes the chronic infections and associated inflammation may be further enhanced that leads to the process of cancer formation [46,47]. Inflammatory cytokines such as tumor necrosis factor (TNF), interleukin-1 (lL-1), lL-6, and chemokines such as lL-8, CXC, and chemo-kine receptor 4 (CXCR4) are the important products produced by inflammatory cells [29]. 

As discussed in sections Introduction and Molecular Basis of Cancer Formation and Development, the formation of cancer is very complex. Generally, the cyclic processes involving oxidation and inflammatory processes (Figs. 1 and 2) lead to the formation of cancer cells. These cancer cells survive if the host is immunocompromised which is generally the case under the conditions of severe oxidative stress [55,58,60]. This leads to the cancer cell proliferation and tumor formation [29]. Finally, due to immune exhaustion, the cancer growth overpowers immune response. Therefore, oxidative stress is the main cause of cancer formation and the subsequent immune exhaustion is the source of cancer growth. Hence, the chemotherapeutics for the treatment of cancer need to be efficient immunomodulators and antioxidants. It is important to note here that the plant polysaccharides with immunomodulatory properties concurrently possess antioxidant activity [5,85] and hence are the ideal candidates for the prevention and treatment of cancer. 

As discussed in the section on stmcture-function relationship of polysaccharides, p-D-glucans and protein bound p-o-glucans are potential candidates for chemotherapeutics for cancer because of their capacity to improve host immunity and hence improve immunosurveiUance. As discussed in section Molecular Basis of Cancer Formation and Development, the process of immunosurveiUance within the host immune system is responsible for the identification and destruction of cancer cells [8,65,72,115,116]. 

Other fundamental pathway to the discovery of anticancer chemotherapeu-tics is to identify the polysaccharides that counter the effects of mutated tumor suppressor gene p53. Mutated p53 gene is present in 50% of all human cancers studied in the literature [37-39]. This mutated gene will lose the ability to effectively bind to DNA. Therefore, the p21 protein cannot be produced and hence disturbs the process of controlled cell division that eventually leads to the formation of tumor [42] (see section Molecular Basis of Cancer Formation and Development ). It has already been demonstrated in the literature that PSP extracted from higher plants reduces cell proliferation by increasing... 

There has also been some concern that benzoic acid and its salts may react with ascorbic acid (present as an ingredient in beverages) to form small quantities of benzene [20]. This is a worry because benzene is toxic and linked to many forms of cancer. Formation of benzene is exacerbated in soft drinks if they are stored for extended periods at elevated temperatures. Although the levels and frequency at which such benzene formation has occurred in the past have not been considered to pose a public health risk, the soft drinks industry has developed methods to prevent or minimize its occurrence. In recent years, the use of benzoates has been reduced because of new processing techniques but it is still necessary to use these preservatives in some beverages to maintain their quality. 

A neutron can get close to a target nucleus more easily than a proton can. Because a neutron has no charge and hence is not repelled by the nuclear charge, it need not be accelerated to such high speeds. An example of neutron-induced transmutation is the formation of cobalt-60, which is used in the radiation treatment of cancer. The three-step process starts from iron-58. First, iron-59 is produced ... 

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