Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0596263 (carcinogenesis)
 64,820 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Epidemiological investigations have shown that cancer risk is inversely related to the consumption of green and yellow vegetables and fruits. Since beta-carotene is present in abundance in these vegetables and fruits, it has been investigated extensively as a possible cancer-preventive agent. However, various carotenoids have also anti-carcinogenic activity. And we found that some of them, such as alpha-carotene, showed higher potency than beta-carotene to suppress carcinogenesis in animal experiments. Thus, we have carried out more extended studies on the cancer-preventive activities of natural carotenoids. For example, lutein, zeaxanthin, lycopene, phytoene, fucoxanthin, peridinin and astaxanthin seem to be promising. In the present study, we confirmed the anti-carcinogenic activities of fucoxanthin and peridinin. Among natural carotenoids, phytoene has not been evaluated precisely since it becomes unstable when it is purified. Here, the cancer-preventive activity of phytoene was demonstrated using new a biotechnological method; i.e., establishment of mammalian cells producing phytoene was followed by the introduction of crtB gene which encodes phytoene synthase, and these cells were proven to acquire the resistance against transformation imposed by transfection of activated oncogenes. Further studies on various natural carotenoids, besides beta-carotene, should be continued to get proper information regarding natural carotenoids in the field of cancer prevention.
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PMID:Cancer prevention by carotenoids. 967 67

Various natural carotenoids, besides beta-carotene, were proven to have anticarcinogenic activity, and some of them showed more potent activity than beta-carotene. Thus, these carotenoids (alpha-carotene, lutein, zeaxanthin, lycopene, beta-cryptoxanthin, fucoxanthin, astaxanthin, capsanthin, crocetin and phytoene), as well as beta-carotene, may be useful for cancer prevention. In the case of phytoene, the concept of 'bio-chemoprevention', which means biotechnology-assisted method for cancerchemoprevention, may be applicable. In fact, establishment of mammalian cells producing phytoene was succeeded by the introduction of crtB gene, which encodes phytoene synthase, and these cells were proven to acquire the resistance against carcinogenesis. Antioxidative phytoene-containing animal foods may be classified as a novel type of functional food, which has the preventive activity against carcinogenesis, as well as the ability to reduce the accumulation of oxidative damages, which are hazardous for human health.
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PMID:Carotenoids in cancer chemoprevention. 1254 64

Various antioxidants in foods, such as phenolic compounds and carotenoids, were proven to have anticarcinogenic activity. In the case of carotenoids, the mixture of them was found to be very effective. In fact, the development of hepatoma in the high risk group of liver cancer, was significantly suppressed by the treatment with natural carotenoids mixture. The role of nitric oxide (NO) in carcinogenesis has been pointed out, since large quantity of NO has been detected in cancer tissues, and the expression of inducible NO synthase (iNOS) was found to correlate with tumor growth and metastasis. Recently, we found that NO possessed tumor initiating activity in mouse skin carcinogenesis. It has been suggested that some parts of pathological effects induced by NO may depend on peroxynitrite, an active metabolite of NO. Thus, we accessed the tumor initiating activity of peroxynitrite, and found that treatment with peroxynitrite (initiator) plus TPA (promoter) resulted in the formation of skin tumors. Under this experimental condition, it has been proven that natural antioxidants, such as curcumin and nobiletin, showed anti-tumor initiating effect. In the case of nobiletin, suppressive effect on iNOS induction has also been demonstrated. It is of interest that suppression of iNOS induction was also observed in phytoene synthase transgenic mouse. After administration of glycerol (a lung tumor promoter), lower induction of iNOS gene was observed in lung of the phytoene producing mice, comparing with that of control mice. Combinational use of various kinds of antioxidants distributed in foods, e.g., mixture of carotenoids and flavonoids, seems to be effective methods for cancer prevention.
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PMID:Cancer prevention by antioxidants. 1563 Feb 52