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)

Increase in neoplasia in offspring after preconception exposure of parents presents puzzling features such as high frequency of effects and lack of Mendelian inheritance. The present study examined the hypothesis that preconception carcinogenesis involves an increase in the rate of occurrence of neoplasms with a spontaneous incidence. Male NIH Swiss mice (12 per group) were exposed 2 weeks before mating (once, ip) to urethane (1.5 g/kg) or chromium(III) chloride (1 mmol/kg). Offspring (48-78/sex/group) were examined for all grossly apparent changes when moribund or at natural death, followed by histopathological diagnosis and statistical analysis. Significant exposure-related changes occurred in multiple organs. Ten to 20 percent of offspring showed changes related to paternal exposure, including at least one sired by most treated males. Pheochromocytomas occurred in both male and female offspring after both treatments, with none in controls. These neoplasms are rare in mice and suggest endocrine dysfunction as a component of preconception carcinogenesis. This was supported by increases in thyroid follicular cell and Harderian gland tumors, ovarian cysts, and uterine abnormalities. Lung tumors were increased in female offspring only. Effects seen in offspring only after paternal urethane exposure were an increase in preneoplasia/neoplasia in the glandular stomach (males) and in females, increased lymphoma but decreased incidence of histiocytic sarcoma. Increases in incidence of male reproductive gland tumors and of renal non-neoplastic lesions occurred only after chromium exposure. Thus, preconception exposure of fathers to toxicants had a significant impact on both neoplastic and non-neoplastic changes in almost all tissues in which these lesions often occur naturally during the aging process.
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PMID:Preconception urethane or chromium(III) treatment of male mice: multiple neoplastic and non-neoplastic changes in offspring. 1040 31

Mouse virus-like 30S RNAs (VL30m) constitute a family of retrotransposons, present at 100 to 200 copies, dispersed in the mouse genome. They display little sequence homology to Moloney murine leukemia virus (MoMLV), do not encode virus-like proteins, and have not been implicated in retroviral carcinogenesis. However, VL30 RNAs are efficiently packaged into MLV particles that are propagated in cell culture. In this study, we addressed whether the 5' region of VL30m could replace the 5' leader of MoMLV functionally in a recombinant vector construct. Our data confirm that the putative packaging sequence of VL30 is located within the 5' region (nucleotides 362 to 1149 with respect to the cap structure) and that it can replace the packaging sequence of MoMLV. We also show that VL30m contains an internal ribosome entry segment (IRES) in the 5' region, as do MoMLV, Friend murine leukemia virus, Harvey murine sarcoma virus, and avian reticuloendotheliosis virus type A. Our data show that both the packaging and IRES functions of the 5' region of VL30m RNA can be efficiently used to develop retrotransposon-based vectors.
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PMID:Identification of an internal ribosome entry segment in the 5' region of the mouse VL30 retrotransposon and its use in the development of retroviral vectors. 1048 90

The anti-HIV drug 3'-azido-3'-deoxythymidine (AZT) is used successfully for reduction of perinatal viral transmission. However toxic side effects including carcinogenesis are possible. To test this, pregnant CD-1 Swiss mice were given 25.0 or 12.5 mg AZT on gestation days 12-18. Previously we reported an increase in lung, liver, and female reproductive system tumors in offspring euthanized at 1 year (Olivero et al., J. Natl. Cancer Inst. 89, 1602-1608, 1997). Findings for all remaining offspring up to 2 years old are reported here. AZT effects were most prominent in female offspring, with a significant threefold increase in lung tumors, a reduction in lymphoblastic and follicle center cell lymphomas, and a significant increase in histiocytic sarcomas (0 in controls, 3% after low-dose AZT, and 8% after high-dose AZT, p = 0.022). Dose-dependent incidences of mammary gland, ovarian, and seminal vesicle tumors were low but significant: 0/106 controls, 3/105 low-dose, and 8/105 high-dose mice presented one of these neoplasms (p = 0.0025). Incidences of females showing any clearly AZT-related neoplasm, in lung, liver, ovary, or mammary gland or histiocytic sarcoma, in the second year, were 12/32 after the low dose and 14/27 after the high dose vs 3/23 controls (p = 0.0045). Also, the sensitivity of neonatal mice was assessed by administration of 25, 50, 100, or 200 mg/kg AZT on postnatal days 1 through 8. The effects at 2 years were similar to those seen after transplacental exposure, with significant increases in lung, liver, and mammary tumors in females. The results confirm that AZT is a moderately effective perinatal carcinogen in mice, targeting several tissue types.
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PMID:Multiorgan transplacental and neonatal carcinogenicity of 3'-azido-3'-deoxythymidine in mice. 1055 26

Chronic infection with hepatitis B virus (HBV) in humans is strongly linked to the development of hepatocellular carcinoma (HCC). Activation of growth-regulatory genes may play a crucial role in carcinogenesis. Proto-oncogene expression has been shown to be higher in HCC tissue with integrated HBV DNA than in the normal liver. Earlier, we showed that the 3' end of the HBV major surface gene (S) (426-855 nucleotides of the S region) is a transactivator of the X promoter-enhancer regulatory element in co-transfection experiments. This region expresses a truncated carboxy terminal S protein extending from amino acid residues 102 to 226. In this study, the truncated S protein (trc-S) was examined for its enhancing activity on several viral and cellular regulatory elements. The results indicate that trc-S activates rous sarcoma virus long terminal repeat (LTR), human T-lymphotropic virus 2 LTR, human immunodeficiency virus 1 LTR, and the c-jun and c-fos promoters. Electrophoretic mobility shift assays carried out to investigate its DNA-binding properties established that trc-S binds to HBV X promoter and oligonucleotides representing binding sites for the AP1 and TFIID transcription factors. The specificity of this interaction was confirmed by using competition experiments and supershift assays. These experiments suggest that trc-S is a transactivator of several cellular and viral promoters and that this activity is mediated by direct interaction with DNA.
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PMID:Hepatitis B virus surface (S) transactivator with DNA-binding properties. 1074 25

In the study of carcinogenesis most interest has focused on carcinomas, as they represent the majority of human cancers. The recognition of the adenoma-carcinoma sequence both in humans and in animal experimental models has given the field of basic oncology the opportunity to elucidate individual mechanisms in the multistep development of carcinoma. The relative scarcity of human sarcomas coupled with the lack of adequate animal models has hampered understanding of the molecular genetic steps involved. We present an experimental model in the rat in which a high incidence of malignant mesenchymal tumors arise around a subcutaneously implanted biomaterial. Nine commercially available biomaterials were implanted in a total of 490 rats of the Fischer strain for 2 years. On average, macroscopic tumors were found in 25.8% of implantation sites over a period from 26 to 110 weeks after implantation. The most frequent tumors were malignant fibrous histiocytomas and pleomorphic sarcomas, although fibrosarcomas, leiomyosarcomas, and angiosarcomas readily developed, the latter especially around polyurethane implants. Of particular interest are the results of a detailed histological study of the capsules around the implanted biomaterials without tumors. Here a spectrum of change from focal proliferative lesions through preneoplastic proliferation to incipient sarcoma could be observed. A parallel immunohistochemical study of peri-implant capsules showed that proliferating cell nuclear antigen was of particular help in identifying these atypical proliferative lesions. To our knowledge this is the first description of a sarcoma model in which preneoplastic lesions can be readily identified and also reproducibly induced. This model provides the molecular biologist with defined stages in the development of mesenchymal malignancy, with which the multistage tumorigenesis hypothesis can be tested, analogous to the well-known adenoma-carcinoma sequence.
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PMID:Biomaterial-induced sarcoma: A novel model to study preneoplastic change. 1075 69

Apart from its role in cell-adhesion, beta-catenin is regarded as an oncoprotein, the cytoplasmic level of which is regulated by APC as a tumor suppressor protein. Changes of chromosome 5q, the region that includes the APC-gene, are known to be important in the pathogenesis of fibromatosis; however, little is known about the significance of APC and beta-catenin in other mesenchymal tumors. Therefore, we used immunohistochemistry and DNA-analysis to investigate four cases of alveolar soft-part sarcoma (ASPS) as a mesenchymal tumor with a distinct histologic appearance. In three cases of ASPS the APC-gene product was found to have strong nuclear expression and only faint cytoplasmic staining. Beta-catenin showed a partly membranous, partly strong intracytoplasmic expression. No gene mutations for APC and beta-catenin were detected in any of the four cases. These investigations suggest that, apart from their function in carcinogenesis and fibromatoses, APC and beta-catenin play a role in the pathogenesis of soft tissue tumors such as ASPS. The significance of a striking nuclear accumulation of non-mutated, virtually functionally active APC-tumor suppressor protein has not yet been investigated. A nuclear function of APC in ASPS in down-regulating nuclear transcription processes linked to overexpression of beta-catenin, as is known in colorectal carcinogenesis, may be hypothesized.
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PMID:APC and beta-catenin in alveolar soft part sarcoma (ASPS)--immunohistochemical and molecular genetic analysis. 1083 86

Malignant soft tissue tumors still represent a source of uncertainty and controversy concerning histogenetic origin and histological behavior. Considering this, chemically induced sarcomas furnish an attractive model for the elucidation of cellular alterations during tumorigenesis. This approach allows us to closely follow cyto- and histological changes within coherent stages of tumor development. The specimen under scrutiny comprised 35 rat tissue samples from day 10 up to day 200 after benzo[a]pyrene injection. Additionally, for comparison and validation two human malignant fibrous histiocytomas (MFH) were investigated. The essential biological significance of protein-carbohydrate interactions warranted the histochemical application of synthetic tools (neo-glycoproteins-NGP) and lectins in order to reveal phenotypical dynamics in this aspect throughout the process of tumor development. Namely, 6 plant lectins (carbohydrate-binding proteins with defined saccharide specificity), 7 custom-made synthetic NGP (as the corresponding ligands visualizing endogenous lectins) and additionally three antibodies were employed. Characteristic cell populations were histochemically demonstrated in four stages of tumor development: exudation (n = 5), mesenchymal proliferation (n = 7), atypical granulation tissue (n = 7) and sarcoma (n = 16). Changes of glycohistochemical binding patterns were in close phenotypic relation to cellular activity, differentiation, local distribution as well as malignant transformation and tumor progression. At present, the new glycobiological features of the malignant phenotype substantiate the assumption that not only glycosylation but also the receptor display is altered upon carcinogenesis. In conclusion, this chronological longitudinal study takes advantage of the combination of a coherent model of tumorigenesis with innovative histochemical tools whose ligands are supposed to act as mediators of cell-cell- and cell-matrix interactions. It clearly demonstrates the suitability of the glycohistochemical method for comparative approaches. The systematic analysis of glycohistochemical determinants will improve our understanding of the early tumor biological processes with potential implications for therapeutic interventions.
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PMID:Glycohistochemical monitoring of chemically induced sarcomas at different stages of tumorigenesis. 1094 65

Cells have some inborn resistance to harmful factors, which could be called physiological or natural resistance. The mechanisms of multixenobiotic resistance (MXR) and multidrug resistance (MDR) have common features in the formation of acquired resistance in microorganisms, carcinogenesis, tumour metastases and chemotherapy or irradiation. ATP-dependent membrane P-glycoprotein, as an MDR efflux pump, glutathione S-transferases and other products of evolutionary resistance-related genes arised for exportation and detoxification of cytotoxic xenobiotics and drugs are transmitted from bacteria to man. On the one hand, this evolutionary MXR as a common biological defence mechanism is a "driving" power to conserve homeostasis of cells, tissues and organs. On the other hand, mutation, selection and simplification of properties are the causes of functional and morphological changes in tumour cells which regress to a more primitive mode of existence (atavism) for adaptation to survival. In the present work are presented data on the forms of E. coli resistant to antibiotics and of sarcoma 45 resistant to alkylic preparations. They may be helpful in revealing the causes of resistance and acquired accelerated growth of cells. The development of tumours as fibromas 14-15 years following injection of a vital dye trypan blue into human skin supports our conception that neoplastic growth is a particular case of the evolutionary resistance of cells adapted to the damaging factors. So, tumour cells adopting the enhancement mechanisms of general biological persistent resistance, i. e. undergoing repeated cycles of malignancy enhancement, adapt themselves to survive under the changed unfavourable conditions.
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PMID:Evolutionary malignant resistance of cells to damaging factors as common biological defence mechanism in neoplastic development. Review of conception. 1114 27

Epidemiologic evidence supports a relationship between vaccination of cats for rabies and feline leukemia virus with the development of soft tissue sarcomas at the site of administration. These tumors are locally invasive and histologically aggressive. As with high-grade soft tissue sarcoma in humans, combination treatment with radiation therapy and surgery provides for optimum tumor control. Feline vaccine-associated sarcoma has become a difficult issue for the veterinary profession for legal, ethical, and clinical reasons. Although most research efforts have focused on therapeutic intervention, this tumor has great potential to provide an informative model for carcinogenesis and genetic susceptibility applicable to cancer in all species, including humans.
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PMID:Vaccine-associated sarcomas in cats: a unique cancer model. 1115 90

The effects of Mn and Cr dusts upon carcinogenesis by polycyclic aromatic hydrocarbons were tested in male Fischer 344 rats. In Experiment I, rats were given i.m. injections of benzo[a]pyrene (BP, 1.2 mg), Mn dust (4.4 mg), and Cr dust (4.4 mg), alone, and in various combinations. By 100 weeks, sarcomas occurred at the injection site in 17/20 rats that received BP alone, versus 10/19 rats that received BP plus Mn dust (P < 0.05). The sarcoma incidences were 0/20 in 3 control groups that received the vehicle, Mn dust alone, or Cr dust alone, and 20/20 in rats that received BP plus Cr dust. In Experiment II, rats were given i.m. injections of BP (0.6 mg), 7,12-dimethylbenz[a]anthracene (DMBA, 0.6 mg), Mn dust (4.4 mg), and Cr dust (4.4 mg), alone, and in various combinations. Local sarcomas occurred in 17/20 rats that received BP alone, versus 5/17 rats that received BP plus Mn dust (P < 0.001). Sarcoma induction was not inhibited when BP was injected in the right thigh and Mn dust in the left thigh (sarcoma incidence = 16/20). The sarcoma incidences were 0/19 in a vehicle control group; 0/18 in 2 control groups that received Mn dust or Cr dust alone; 18/20 in rats that received BP plus Cr dust; 14/20 in rats that received DMBA alone; 17/19 in rats that received DMBA plus Mn dust; and 13/18 in rats that received DMBA plus Cr dust. These experiments show that Mn dust inhibits the carcinogenicity of BP when the Mn dust and BP are administered to rats by a single i.m. injection. Under identical conditions, Mn dust does not affect the carcinogenicity of DMBA; Cr dust does not affect the carcinogenicity of BP or DMBA.
Carcinogenesis 1980 Jul
PMID:Manganese inhibition of sarcoma induction by benzo[a]pyrene in rats. 1121 37


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