Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The rasH2 mice are hemizygous transgenic mice carrying the human prototype c-Ha-ras gene with its own promoter region, and have been used in 6-month short-term carcinogenicity tests for pharmaceutical drugs in accordance with the recommendation of the International Conference on Harmonization of Technical Requirements of Pharmaceuticals for Human Use (ICH). Based on the validation studies, it has been recognized that they are very susceptible to genotoxic carcinogens. To elucidate the mechanism of the enhanced carcinogenesis, spontaneous and chemically induced tumors in rasH2 mice have been subjected to molecular analyses, but the results have thus far been equivocal. This article focuses on the possible molecular mechanism of enhanced carcinogenesis in rasH2 mice, based on the results of a search in the literature. In addition, there are several reports suggesting lesser carcinogenic susceptibility of rasH2 mice to some carcinogens: Malignant lymphomas were induced by treatment with phenolphthalein in heterozygous p53 knockout mice, but not in rasH2 mice, and ethinylestradiol, uterine tumor promoter, resulted in depression of uterine proliferative lesions in rasH2 mice. In this review, the possible mechanisms of why rasH2 mice were less sensitive for these carcinogens are also discussed.
 ...
PMID:Possible mechanism on enhanced carcinogenesis of genotoxic carcinogens and unsolved mechanisms on lesser carcinogenic susceptibility to some carcinogens in rasH2 mice. 1474 41

The cytochrome P450 (CYP1A1) enzyme metabolically activates many polycyclic aromatic hydrocarbons, including benzo[a]pyrene (BaP), to DNA- and protein-binding intermediates that are associated with toxicity, mutagenesis, and carcinogenesis. As a result, it is widely accepted that CYP1A1 potentiates the toxicity of this class of chemicals. In distinct contrast, we show here that CYP1A1 inducibility is essential in the detoxication of oral BaP. We compared Cyp1a1(-/-) knockout mice, having the genetic absence of the CYP1A1 enzyme, with Cyp1a1(+/+) wild-type mice. At an oral BaP dose of 125 mg/kg/day, Cyp1a1(-/-) mice died within 30 days whereas Cyp1a1(+/+) mice displayed no outward signs of toxicity. The rate of BaP clearance was 4-fold slower in Cyp1a1(-/-) than Cyp1a1(+/+) mice. The cause of death in Cyp1a1(-/-) mice receiving oral BaP seemed to be immunotoxicity, including toxic chemical depression of the bone marrow; some toxic effects in Cyp1a1(-/-) mice were noted at a BaP dose as low as 1.25 mg/kg/day. DNA post-labeling studies demonstrated dramatically higher BaP-DNA adduct levels in all Cyp1a1(-/-) tissues assayed, with the exception of the small intestine, which is probably a major site of BaP metabolism in Cyp1a1(+/+) mice. Different BaP-DNA adduct patterns were also observed between the two genotypes receiving oral BaP. Despite previous studies in vitro and in cell culture that have shown a participatory role for CYP1A1 in BaP toxicity, the present data indicate that, in the intact animal, inducible CYP1A1 is extremely important in detoxication and protection against oral BaP toxicity.
 ...
PMID:Oral exposure to benzo[a]pyrene in the mouse: detoxication by inducible cytochrome P450 is more important than metabolic activation. 1510 51

We report a case of advanced colon cancer which was supposed to have arisen from a hyperplastic polyp in a 68-year-old man. Colonoscopy revealed a depressed reddish area with a surrounding elevated lesion that was of a faded color compared with the normal mucosa. After the mucosal surface had been sprayed with crystal violet dye, magnifying colonoscopy showed an amorphous area in the central depression and the surrounding, slightly elevated lesion had an asteroid pattern. The depressed area was therefore considered to be a colonic cancer surrounded by a hyperplastic polyp. Endoscopic ultrasonography showed that the lesion was infiltrating further than the deep submucosal layer and it was therefore decided to treat the patient by laparoscopically assisted right hemicolectomy. The depressed lesion was found to be a well-differentiated adenocarcinoma invading the muscularis propria (diagnosed as IIc + IIa-like advanced adenocarcinoma). The surrounding flat elevated lesion was found to be hyperplastic mucosa. No adenomatous lesions were found. There have been few reported cases in which a preoperative diagnosis of carcinoma in a hyperplastic polyp has been made, but the possibility of carcinogenesis from hyperplastic polyps has come under consideration recently. This case was considered to be important because it raises the possibility that nonpolypoid cancer can develop from a hyperplastic polyp.
 ...
PMID:Small invasive colonic cancer occurring in a hyperplastic polyp. 1532 79

The p53 binding protein 2 (53BP2) has been identified independently as the interacting protein to p53, Bcl-2, and p65 subunit of nuclear factor kappaB (NF-kappaB). It was demonstrated that over-expression of 53BP2 (renamed as 53BP2S) induces apoptotic cell death. In this study we explored the effect of NF-kappaB activation elicited by a physiological NF-kappaB inducer, interleukin-1beta (IL-1beta), and anti-apoptotic Bcl-2 family proteins on the 53BP2S-mediated apoptosis. We found that both NF-kappaB activation and Bcl-2 family proteins could prevent the 53BP2S-mediated depression of mitochondrial transmembrane potential, activation of caspase-9, cleavage of poly ADP ribose polymerase (PARP), and cell death. These observations suggested that 53BP2S/Bbp and its directly or indirectly interacting proteins might play crucial roles in the regulation of apoptosis and contribute to carcinogenesis. It is also suggested that 53BP2S/Bbp induces apoptosis through the mitochondrial death pathway presumably by counteracting the actions of anti-apoptotic Bcl-2 family proteins. The regulatory network of the 53BP2S-mediated apoptosis cascade including its interacting proteins is discussed.
 ...
PMID:Inhibition of the 53BP2S-mediated apoptosis by nuclear factor kappaB and Bcl-2 family proteins. 1609 44

The p38 mitogen-activated protein kinase (MAPK) and activated MAPK transcription factors c-jun, c-myc, and elk-1 were investigated in rat enterocytes after sublethal poisoning with soman to study the pathogenetic mechanism of nonspecific long-term effects of nerve agents. Wistar rats were poisoned by intramuscular administration of soman at a dose 60 microg x kg(-1) (70% LD(50)) and sacrificed by cervical dislocation 3 and 5 days after poisoning. Control groups were administered physiologic saline instead of soman. Protein expression in immunohistochemically stained samples from colon transversum of control and poisoned rats was measured using image analysis. In comparison with control groups, activated p38 MAPK from soman-poisoned rats was significantly depressed at both time intervals. c-myc and c-jun expression was significantly increased 3 days after soman poisoning. On the other hand, a decrease in c-myc and c-jun expression was observed 5 days after soman poisoning. No changes in elk-1 expression were found. Long-term depression of MAPK pathway members might allow cells to proliferate in poisoned rats. This mechanism can be linked with apoptosis and carcinogenesis.
 ...
PMID:Alteration of mitogen-activated protein kinase pathway after soman poisoning. 1761 12

Mitochondrial dysfunction is a hallmark of almost all diseases. Acquired or inherited mutations of the mitochondrial genome DNA may give rise to mitochondrial diseases. Another class of disorders, in which mitochondrial impairments are initiated by extramitochondrial factors, includes neurodegenerative diseases and syndromes resulting from typical pathological processes, such as hypoxia/ischemia, inflammation, intoxications, and carcinogenesis. Both classes of diseases lead to cellular energetic depression (CED), which is characterized by decreased cytosolic phosphorylation potential that suppresses the cell's ability to do work and control the intracellular Ca(2+) homeostasis and its redox state. If progressing, CED leads to cell death, whose type is linked to the functional status of the mitochondria. In the case of limited deterioration, when some amounts of ATP can still be generated due to oxidative phosphorylation (OXPHOS), mitochondria launch the apoptotic cell death program by release of cytochrome c. Following pronounced CED, cytoplasmic ATP levels fall below the thresholds required for processing the ATP-dependent apoptotic cascade and the cell dies from necrosis. Both types of death can be grouped together as a mitochondrial cell death (MCD). However, there exist multiple adaptive reactions aimed at protecting cells against CED. In this context, a metabolic shift characterized by suppression of OXPHOS combined with activation of aerobic glycolysis as the main pathway for ATP synthesis (Warburg effect) is of central importance. Whereas this type of adaptation is sufficiently effective to avoid CED and to control the cellular redox state, thereby ensuring the cell survival, it also favors the avoidance of apoptotic cell death. This scenario may underlie uncontrolled cellular proliferation and growth, eventually resulting in carcinogenesis.
 ...
PMID:Mitochondria and energetic depression in cell pathophysiology. 1956 50

Circadian rhythms regulate diverse physiologic processes, including homeostatic functions of steroid hormones and their receptors. Perturbations of these rhythms are associated with pathogenic conditions, such as depression, diabetes, and cancer. Androgens play an important role in both normal development and carcinogenesis of the prostate. In the present study, we investigated a potential role for the core clock factor Per1 in the pathogenesis of prostate cancer. Serum-shocked synchronized prostate cancer cells displayed disrupted circadian rhythms compared with the normal prostate tissue. Using Oncomine to perform a meta-analysis of microarray expression studies, we found that Per1 is down-regulated in human prostate cancer samples compared with normal prostates. Reporter assays showed that Per1 inhibited transactivation of the androgen receptor (AR) both in 293T cells overexpressing the AR and in the prostate cancer cell line LNCaP. Forced expression of Per1 in LNCaP cells diminished the expression of known androgen-sensitive genes following stimulation with dihydrotestosterone. We showed that Per1 physically interacted with AR; in addition, we found that Per1 itself is regulated by androgens in prostate cancer cells. Overexpression of Per1 in prostate cancer cells resulted in significant growth inhibition and apoptosis. Our results support the emerging role of circadian genes as key players in malignant transformation. Further elucidating the connections between clock genes and the AR pathway could benefit the development of new therapeutic strategies for prostate cancer as well as provide insights into chronotherapy as a way to optimize current therapies.
 ...
PMID:A role for the clock gene per1 in prostate cancer. 1975 89

Dietary factors are considered crucial for the prevention of initiating events in the multistep progression of colon carcinoma. There is substantial evidence that zinc may play a pivotal role in host defense against several malignancies, including colon cancer. The present study was conducted to evaluate the kinetics of (65)Zn utilization following experimental colon carcinogenesis in rat model. Twenty rats were segregated into two groups viz., untreated control and dimethylhydrazine (DMH) treated. Colon carcinogenesis was established through weekly subcutaneous injections of DMH (30 mg/kg body weight) for 16 weeks. Whole body (65)Zn kinetics followed two compartment kinetics, with Tb(1) representing the initial fast component of the biological half-life and Tb(2), the slower component. The present study revealed a significant depression in the Tb(1) and Tb(2) components of (65)Zn in DMH treated rats. Further, DMH treatment caused a significant increase in the percent uptake values of (65)Zn in the colon, small intestine, kidney and blood, whereas a significant decrease was observed in the liver. Subcellular distribution revealed a significant increase in (65)Zn uptake in the mitochondrial and microsomal fractions following 16 weeks of DMH supplementation. In conclusion, the present study demonstrated a slow mobilization of (65)Zn during promotion of experimentally induced colon carcinogenesis and provides a physiological basis for the role of (65)Zn in colon tumorigenesis, which may have clinical implications in the management of colon cancer.
 ...
PMID:65Zn kinetics as a biomarker of DMH induced colon carcinogenesis. 2119 81

Human chorionic gonadotropin (hCG) is as efficient as pregnancy in protecting the rat mammary gland against carcinogenesis. The effect of both pregnancy and hCG is a lasting one, without secondary effect on body weight, and endocrine related organs. The protective effect of hCG as in pregnancy is due to gland differentiation associated with depression on cell proliferation and synthesis of inhibin by the mammary epithelial cells. The protective effect of hCG is further demonstrated after carcinogen administration indicating a decrease of tumor progression. Whereas hCG action is mediated mainly through the ovary, a direct effect has been demonstrated. This data has been further confirmed by showing that hCG treatment inhibits the proliferation of human breast epithelial cells. This inhibition is associated with synthesis of new gene products, some of which have been identified by immunoprecipitation and Northern blot analysis to be alpha and beta inhibin subunits. Collectively, all these data indicate that inhibin may play an important role in cell growth and differentiation of the mammary epithelia during the physiological process of pregnancy or by the action of hCG. Further studies delineating the pathway through which hCG and inhibin modulate the fate of neoplastic cells would allow us to utilize physiologic mechanisms controlling cell proliferation in breast cancer prevention and therapy.
 ...
PMID:Role of HCG and inhibin in breast-cancer (review). 2156 23

The purpose of the present study is to test the validity of the steroid carcinogenesis hypothesis in humans by investigating the problem whether or not a cancer-specific change of the hormonal milieu emerges at a specified stage of life where the growth rate of cancer risk is at its zenith. A case-control study of 14 urinary steroid excretions was conducted for each of 3 human neoplasias. The identification and the size (in parenthesis) of the population units used in this study were,given as follows: a) the male gastric cancer group (421); b) the male control group (104); c) the female breast cancer group (245); d) the cervical cancer group (345); e) the female control group (127). Two kinds of steroid parameters were employed for the statistical analysis of hormonal data: a) the logarithm of a steroid excretion figure (mu g/day), as expressed by log x; b) the logarithm of a relative weight of a given steroid to tetrahydrocortisol, as expressed by log x/THF. The case-control difference for each parameter was expressed in terms of a t-value of Student's t-test. The steroid deviation profile was prepared for each neoplasia and for each of the log x data set and the log x/THF data set. The results obtained are as follows: a) the 2 steroid parameters (log x and log x/THF) for each of 14 urinary steroids were both subject to change with the progress of host age. The rate of age-dependent change was different for each steroid parameter and for each population unit. b) The above differential age dependency of the steroid parameters gave rise to a continual transition of the steroid deviation profile in the course of aging. c) The hormonal traits of male gastric cancer, female breast cancer and cervical cancer were described each as a complex of androgen depression and glucocorticoid stimulation (male gastric cancer), a sequential emergence of premenopausal progestin depression and postmenopausal predominance of glucocorticoid over androgen (female breast cancer), and a complex of androgen-glucocorticoid depression over progestin (cervical cancer). d) The emergence of the above cancer-specific steroid disorders chronologically coincided with the quasiexponential growth phase of cancer risk (and slow growth phase of cancer risk in postmenopausal breast cancer). e) The usefulness of the log x/THF type deviation profile for the assessment of the hormonal milieu of the host was verified by both theoretical approach to the problem and its application to the real data of a case-control study. f) The age dependent decline of androgens was generally much faster in their progressions than that of glucocorticoids - a finding to suggest the possibility that the production of a cancer-specific steroid deviation profile might have taken the form of the stress shift of Hans Selye, since both phenomena share depletion of gonadal steroids relative to glucocorticoid in common. The etiological relevancy of the 3 cancer-specific steroid changes to the geneses of 3 cancers:was discussed in the light of the experimental pathology studies in our laboratory as well as in other laboratories.
 ...
PMID:The relation between the aging of the steroid generating system and the geneses of cancers of the stomach, the breast and the uterine cervix. 2159 38


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>