Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0699790 (colon cancer)
 28,837 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Melatonin is a neuroendocrine hormone secreted by the pineal gland to transduce the body's circadian rhythms. An internal 24 hour time keeping system (biological clock) regulated by melatonin, controls the sleep-wake cycle. Melatonin production is a highly conserved evolutionary phenomenon. The indole hormone is synthesized in the pinealocytes derived from photoreceptors. Altered patterns and/or levels of melatonin secretion have been reported to coincide with sleep disorders, jetlag, depression, stress, reproductive activities, some forms of cancer and immunological disorders. Lately, the physiological and pathological role of melatonin has become a priority area of investigation, particularly in breast cancer, melanoma, colon cancer, lung cancer and leukemia. According to the 'melatonin hypothesis' of cancer, the exposure to light at night (LAN) and anthropogenic electric and magnetic fields (EMFs) is related to the increased incidence of breast cancer and childhood leukaemia via melatonin disruption. Melatonin's hypothermic, antioxidant and free radical scavenging properties, attribute it to an immunomodulator and an oncostatic agent as well. Many clinical studies have envisaged the potential therapeutic role of melatonin in various pathophysiological disorders, particularly cancer. A substantial reduction in risk of death and low adverse effects were reported from various randomized controlled trials of melatonin treatment in cancer patients. This review summarizes the physiological significance of melatonin and its potential role in cancer therapy. Furthermore, the article focuses on melatonin hypothesis to represent the cause-effect relationship of the three aspects: EMF, LAN and cancer.
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PMID:Melatonin in pathogenesis and therapy of cancer. 1713 Jun 68

The authors examined the impact of a widower's preparedness before his wife's death from cancer on his risk of long-term morbidity. In a population-based study, 691 (76%) of 907 Swedish men who lost a wife to breast, ovarian, or colon cancer in 2000 or 2001 answered an anonymous questionnaire in 2004 or 2005 measuring preparedness at the time of the wife's death and psychological well-being at follow-up. Men aged 38-61 years with a low degree of preparedness at the time of their spouse's death had increased risk of psychological morbidity and other symptoms, such as anxiety (adjusted relative risk (aRR) = 2.1, 95% confidence interval (CI): 1.0, 4.3), a heightened startle response (aRR = 5.3, 95% CI: 1.2, 23.6), emotional numbness (aRR = 2.1, 95% CI: 1.2, 3.6), little or no grief resolution (aRR = 2.7, 95% CI: 1.3, 5.4), and sleep disorders (aRR = 2.3, 95% CI: 1.2, 4.3), 4-5 years after the loss. For older widowers (aged 62-80 years), a low degree of preparedness increased the risk of having repeated painful memories (aRR = 2.8, 95% CI: 1.5, 5.2) and a heightened startle response (aRR = 5.7, 95% CI: 1.5, 21.4) at follow-up. These results show that to improve the long-term psychological well-being of widowers, it may be fruitful to identify care-related facilitators and inhibitors of preparedness.
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PMID:Long-term harm of low preparedness for a wife's death from cancer--a population-based study of widowers 4-5 years after the loss. 2063 79

Numerous epidemiologic studies have demonstrated that regular physical activity convincingly reduces risk for colon cancer, probably for endometrium and postmenopausal breast cancer, and possibly for premenopausal breast, prostate, lung, and pancreas cancer. Relative risk reductions range from 10-30%. On the absolute scale about 9-19% of the most frequent cancers can be attributed to a lack of sufficient physical activity. Thus, exercise, as a modifiable health behavior, has a strong potential for primary cancer prevention. Current recommendations call for at least 30-60 min of moderate to vigorous activity daily. Physical activity is also increasingly gaining importance in cancer treatment and is now considered to be feasible, safe, and even recommended in almost all stages of disease. Randomized-controlled trials show that disease- and treatment-related symptoms, such as fatigue, sleep disorders, and depression which sometimes limit quality of life in cancer patients over years, can be reduced by physical activity. For disease-specific and total mortality, clinical studies are not yet available. However, preliminary observational studies with breast, colon, and prostate cancer patients show risk reductions.
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PMID:[Effects of physical activity on cancer risk and disease progression after cancer diagnosis]. 2228 45

Metabolic processes have to be regulated tightly to prevent waste of energy and to ensure sufficient detoxification. Most anabolic processes operate in a timely manner when energy intake is the highest, while catabolism takes place in energy spending periods. Endobiotic and xenobiotic metabolism are therefore under circadian control. Circadian regulation is mediated through the suprachiasmatic nucleus (SCN), a master autonomous oscillator of the brain. Although many peripheral organs have their own oscillators, the SCN is important in orchestrating and entraining organs according to the environmental light cues. However, light is not the only signal for entrainment of internal clocks. For endobiotic and xenobitoic detoxification pathways, the food composition and intake regime are equally important. The rhythm of the liver as an organ where the major metabolic pathways intersect depends on SCN signals, signals from endocrine tissues, and, importantly, the type and time of feeding or xenobiotics ingestion. Several enzymes are involved in detoxification processes. Phase I is composed mainly of cytochromes P450, which are regulated by nuclear receptors. Phase II enzymes modify the phase I metabolites, while phase III includes membrane transporters responsible for the elimination of modified xenobiotics. Phases I-III of drug metabolism are under strong circadian regulation, starting with the drug-sensing nuclear receptors and ending with drug transporters. Disturbed circadian regualtion (jet-lag, shift work, and dysfunction of core clock genes) leads to changed periods of activity, sleep disorders, disturbed glucose homeostasis, breast or colon cancer, and metabolic syndrome. As many xenobiotics influence the circadian rhythm of the liver, bad drug administration timing can worsen the above listed effects. This review will cover the major hepatic circadian regulation of endogenous and xenobiotic metabolic pathways and will provide examples of how good timing of drug administration can change drug failure to treatment success.
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PMID:Circadian regulation of the hepatic endobiotic and xenobitoic detoxification pathways: the time matters. 2230 88

Clock genes are expressed in a self-perpetuating, circadian pattern in virtually every tissue including the human gastrointestinal tract. They coordinate cellular processes critical for tumor development, including cell proliferation, DNA damage response and apoptosis. Circadian rhythm disturbances have been associated with an increased risk for colon cancer and other cancers. This mechanism has not been elucidated, yet may involve dysregulation of the 'period' (PER) clock genes, which have tumor suppressor properties. A variable number tandem repeat (VNTR) in the PERIOD3 (PER3) gene has been associated with sleep disorders, differences in diurnal hormone secretion, and increased premenopausal breast cancer risk. Susceptibility related to PER3 has not been examined in conjunction with adenomatous polyps. This exploratory case-control study was the first to test the hypothesis that the 5-repeat PER3 VNTR sequence is associated with increased odds of adenoma formation. Information on demographics, medical history, occupation and lifestyle was collected prior to colonoscopy. Cases (n=49) were individuals with at least one histopathologically confirmed adenoma. Controls (n=97) included patients with normal findings or hyperplastic polyps not requiring enhanced surveillance. Unconditional multiple logistic regression was used to calculate odds ratios (ORs) with 95% confidence intervals (CIs), after adjusting for potential confounding. Adenomas were detected in 34% of participants. Cases were more likely to possess the 5-repeat PER3 genotype relative to controls (4/5 OR, 2.1; 95% CI, 0.9-4.8; 5/5 OR, 5.1; 95% CI, 1.4-18.1; 4/5+5/5 OR, 2.5; 95% CI, 1.7-5.4). Examination of the Oncomine microarray database indicated lower PERIOD gene expression in adenomas relative to adjacent normal tissue. Results suggest a need for follow-up in a larger sample.
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PMID:Case-control study of the PERIOD3 clock gene length polymorphism and colorectal adenoma formation. 2550 48

Shiftwork became common during the last few decades with the growing demands of human life. Despite the social inactivity and irregularity in habits, working in continuous irregular shifts causes serious health issues including sleep disorders, psychiatric disorders, cancer, and metabolic disorders. These health problems arise due to the disruption in circadian clock system, which is associated with alterations in genetic expressions. Alteration in clock controlling genes further affects genes linked with disorders including major depression disorder, bipolar disorder, phase delay and phase advance sleep syndromes, breast cancer, and colon cancer. A diverse research work is needed focusing on broad spectrum changes caused by jet lag in brain and neuronal system. This review is an attempt to motivate the researchers to conduct advanced studies in this area to identify the risk factors and mechanisms. Its goal is extended to make the shift workers aware about the risks associated with shiftwork.
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PMID:Shiftwork-Mediated Disruptions of Circadian Rhythms and Sleep Homeostasis Cause Serious Health Problems. 2960 11