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)

Although the acute toxic effects of cadmium in mice vary greatly with strain, relatively little is known about strain differences in cadmium carcinogenesis. Therefore, this work was performed to assess the chronic toxic and carcinogenic effects of cadmium in two strains of mice generally thought to be susceptible to the acute effects of cadmium. Male DBA/2NCr (DBA) and NFS/NCr (NFS) mice were given CdCl2 (40 mumol/kg, sc) either as a single dose (1 x 40) or as weekly doses for 16 weeks (16 x 40) starting at 8 weeks of age. Controls received saline. The animals were observed for the next 104 weeks and mice at risk were defined as those surviving to the time of appearance of a particular tumor. Cadmium-induced dose-related increases in lymphoma (primarily follicular center cell) incidence (1 x 40, 11 cases/23 mice at risk; 16 x 40, 16/28) over control (7/27) in DBA mice but not in NFS mice. Only NFS mice receiving repeated cadmium injections (16 x 40) showed sarcoma development at the injection site (9/35), as no sarcomas occurred in control NFS mice or any group of DBA mice. On the other hand, cadmium-treated (16 x 40) NFS mice, but not DBA mice, had more hepatocellular adenomas and carcinomas (9/27) than control (1/15) but only at the high dose (16 x 40). More cadmium-treated NFS mice had pulmonary tumors than controls, but only at the lower dose (1 x 40). Although testicular tumors were rare, nonneoplastic lesions (fibrosis and mineralization) were induced by cadmium to a similar extent in both strains. Clearly cadmium carcinogenicity varies widely with strain, indicating a genetic basis to susceptibility. The basis of these strain differences deserves further study.
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PMID:Chronic toxic and carcinogenic effects of cadmium chloride in male DBA/2NCr and NFS/NCr mice: strain-dependent association with tumors of the hematopoietic system, injection site, liver, and lung. 795 59

Recent investigations have shown the presence of ras gene mutations and human papillomavirus (HPV) DNA in prostate carcinomas. In the present study, secondary adult human prostatic epithelial cells, upon transfection with a plasmid containing the entire HPV-18 genome, acquired an indefinite life-span in culture but did not undergo malignant conversion. Subsequent infection of these immortalized cells with the Kirsten murine sarcoma virus, which contains an activated Ki-ras oncogene, induced morphological transformation that led to the acquisition of neoplastic properties. These findings demonstrate the malignant transformation of adult human prostate epithelial cells in culture by a combination of viral oncogenes and the successive roles of HPV infection and Ki-ras activation in a multistep process responsible for prostate carcinogenesis.
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PMID:Stepwise immortalization and transformation of adult human prostate epithelial cells by a combination of HPV-18 and v-Ki-ras. 799 49

Human skin keratinocytes after malignant neoplastic transformation by infection with Kirsten murine sarcoma virus (KiMSV) or transfection with pSV2 ras (containing an activated c-Ha-ras oncogene) showed a DNA repair deficiency(ies). The repair deficiency was manifest as an abnormally high frequency of chromatid breaks and gaps persisting after X-ray-induced DNA damage inflicted during the G2 phase of the cell cycle. Non-tumorigenic control cells at that time were clearly repair-efficient. By analyzing benign and malignant tumorigenic HaCaT-ras clones, we could exclude ras p21 oncoprotein expression as the causal mechanism for repair deficiency, since both clone types expressed similar levels of the mutated protein and only the malignant tumorigenic cells showed repair deficiency. The results suggest that mutated p21 ras provided the human keratinocytes with a growth advantage in vivo (benign tumor growth), but acquisition of repair deficiency is required for progression from benign to malignant state.
Carcinogenesis 1994 Jan
PMID:Association of deficient DNA repair during G2 phase with progression from benign to malignant state in a line of human skin keratinocytes transfected with ras oncogene. 829 45

Investigations of mechanisms of human prostate carcinogenesis are limited by the unavailability of a suitable in vitro model system. We have demonstrated that an immortal, but nontumorigenic, human epithelial cell line (267B1) established from fetal prostate tissue can be malignantly transformed by a biological carcinogen, and can serve as a useful model for investigations of the progression steps of carcinogenesis. Activated Ki-ras was introduced into 267B1 cells by infection with the Kirsten murine sarcoma virus. Morphological alterations and anchorage-independent growth were observed; when cells were injected into nude mice, poorly differentiated adenocarcinomas developed. These findings represent the first evidence of malignant transformation of human prostate epithelial cells in culture, and support a role for Ki-ras activation in a multistep process for prostate neoplastic transformation.
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PMID:Neoplastic transformation of a human prostate epithelial cell line by the v-Ki-ras oncogene. 837 90

A recently described splice variant of CD44 expressed in metastasizing cell lines of rat tumors has been shown to confer metastatic potential to a non-metastasizing rat pancreatic carcinoma cell line and to non-metastasizing sarcoma cells. Homologues of this variant as well as several other CD44 splice variants are also expressed at the RNA level in human carcinoma cell lines from lung, breast, and colon, and in immortalized keratinocytes. Using antibodies raised against a bacterial fusion protein encoded by variant CD44 sequences, we studied the expression of variant CD44 glycoproteins in normal human tissues and in colorectal neoplasia. Expression of CD44 variant proteins in normal human tissues was readily found on several epithelial tissues including the squamous epithelia of the epidermis, tonsils, and pharynx, and the glandular epithelium of the pancreatic ducts, but was largely absent from other epithelia and from most non-epithelial cells and tissues. In human colorectal neoplasia CD44 variant proteins, including homologues of those which confer metastatic ability to rat tumors, were found on all invasive carcinomas and carcinoma metastases. Interestingly, focal expression was also observed in adenomatous polyps, expression being related to areas of dysplasia. The distribution of the CD44 variants in human tissues suggests that they play a role in a few restricted differentiation pathways and that in colorectal tumors one of these pathways has been reactivated. The finding that metastasis-related variants are already expressed at a relatively early stage in colorectal carcinogenesis and tumor progression, i.e., in adenomatous polyps, suggests the existence of a yet unknown selective advantage linked to CD44 variant expression. The continued expression in metastases would be compatible with a role in the metastatic process.
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PMID:A human homologue of the rat metastasis-associated variant of CD44 is expressed in colorectal carcinomas and adenomatous polyps. 841 89

Epidemiological studies have indirectly linked compounds of chromium, nickel and arsenic to human carcinogenesis. However, there is no evidence that metal compounds can transform human cells to the tumorigenic phenotype in culture. We show here that exposure to 36 microM NiSO4 for 48-96 h results in transformation of an immortal, nontumorigenic, osteoblast-like cell line, HOS TE85, to the tumorigenic phenotype. Continuous passaging following treatment leads to the formation of a few dense foci. The cells isolated and expanded from the foci are morphologically transformed, and form anchorage-independent colonies of the size and abundance comparable to that formed by Kirsten murine sarcoma virus transformed HOS TE85 cells. The transformed cells from tumors in nude mice, have enhanced levels of plasminogen activators and have lost the ability to form model bone matrix on extended culture in the presence of ascorbic acid and beta-glycerophosphate. A number of cell lines have been established from nude mouse tumors. Cytogenetic analysis reveals 16 marker chromosomes and an aberrant chromosome 16. This is the first report of the transformation of a human cell line to tumorigenic phenotype by a metal carcinogen.
Carcinogenesis 1993 May
PMID:Transformation of immortal, non-tumorigenic osteoblast-like human osteosarcoma cells to the tumorigenic phenotype by nickel sulfate. 850 88

Iscador, an extract from the semi-parasitic plant Viscum album, was found to inhibit 20-methylcholanthrene-induced carcinogenesis in mice. Intraperitoneal administration of Iscador (1 mg/dose) twice weekly for 15 weeks could completely inhibit 20-methylcholanthrene-induced sarcoma in mice and protect these animals from tumour-induced death. Iscador was found to be effective even at lowered doses. After administration of 0.166, 0.0166 and 0.00166 mg/dose 67, 50 and 17% of animals respectively did not develop sarcoma.
Carcinogenesis 1996 May
PMID:Prevention of 20-methylcholanthrene-induced sarcoma by a mistletoe extract, Iscador. 864 Sep 20

The association between genetic disorders and diverse cancers has provided clues for laboratory research into carcinogenesis. Such an opportunity now arises from studies of cancer in Werner syndrome (WRN). Soft-tissue sarcoma (STS) and benign meningioma have been associated with WRN, an autosomal recessive disorder characterized by premature aging, more commonly reported in Japan than elsewhere, in part because of inbreeding. In the literature we found 124 case-reports of neoplasia and WRN from Japan and 34 from outside Japan, 1939-August, 1995. They reveal a greater diversity of neoplasia in WRN than was previously known. In Japanese, there were 127 cancers, 14 benign meningioma, and 5 myeloid disorders, as compared with 30, 7 and 2 respectively in non-Japanese. The ratio of epithelial to non-epithelial cancers was about 1:1 for Japanese and for non-Japanese instead of the usual 10:1. Both series had excess of STS, osteosarcoma, myeloid disorders, and benign meningioma. In addition, the Japanese had an excess of thyroid cancer (20 versus 2 cases in non-Japanese) and melanoma (21 versus 3 cases), including 5 intranasal and 13 of the feet. STS, osteosarcoma, melanoma, and thyroid carcinoma accounted for 57% of all cancer in WRN as compared with 2% expected based on the Osaka population at 25-64 years of age. Multiple tumors were reported in 19 Japanese and 5 non-Japanese. In Japan, nine first-degree relatives had WRN and cancer, six of whom were concordant as to site and/or cell type. The WRN gene has been mapped to chromosome 8p. The high frequency of thyroid cancer and melanoma in Japanese, not found in Caucasians, may be related to a report of linkage disequilibrium with the WRN gene in Japanese but not in Caucasians and to haplotype differences within and between the two races, suggesting multiple independent mutations.
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PMID:Excess of rare cancers in Werner syndrome (adult progeria). 872 14

Systemic administration of copper, an essential trace metal in the human body, has never been reported to be carcinogenic in animals. We investigated the induction of tumors by the cupric complex of nitrilotriacetic acid (Cu-NTA) in male Wistar rats. Thirty-two animals received ip injections of Cu-NTA, 3 to 5 mg of copper/kg body weight 5 days a week for 12 weeks, and were kept under close observation. For comparison, 31 animals received ip injections of ferric nitrilotriacetate (Fe-NTA), 5 to 10 mg of iron/kg body weight, and 16 animals received nitrilotriacetic acid (NTA) alone at the molar dose equivalent to Cu-NTA for the same period of time. Sixteen animals were left untreated as controls. Fourteen animals in the Cu-NTA group died of hepatic failure during the treatment period, and renal cell carcinoma (RCC) was induced in eight animals (25%). Of these, four animals died of either pulmonary metastasis or intraperitoneal hemorrhage. A total of 12 RCC were obtained, of which six tumors were > or = 5 mm. The Cu-NTA group yielded fewer RCC and required a longer latent period for their incubation than the Fe-NTA group. Furthermore, the Cu-NTA group showed one hepatocellular carcinoma and one high-grade sarcoma of hepatic origin. No renal or hepatic tumor was observed in the NTA or control groups. The nontumorous part of the kidney treated with Cu-NTA presented hemosiderosis caused by copper-induced hemolytic anemia. This is the first report that systemic administration of copper compounds can induce malignant tumors in animals. Not only copper but also iron may play a role in the Cu-NTA-induced renal carcinogenesis model.
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PMID:Induction of renal cell carcinoma in male Wistar rats treated with cupric nitrilotriacetate. 876 24

Curcumin, which is a widely used dietary pigment and spice, has been demonstrated to be an effective inhibitor of tumor promotion in mouse skin carcinogenesis. We report that curcumin induces cell shrinkage, chromatin condensation, and DNA fragmentation, characteristics of apoptosis, in immortalized mouse embryo fibroblast NIH 3T3 erb B2 oncogene-transformed NIH 3T3, mouse sarcoma S180, human colon cancer cell HT-29, human kidney cancer cell 293, and human hepatocellular carcinoma Hep G2 cells, but not in primary culture of mouse embryonic fibroblast C3H 10T1/2, rat embryonic fibroblast, and human foreskin fibroblast cells in a concentration- and time-dependent manner. Many cellular and biochemical effects of curcumin in mouse fibroblast cells have been reported, such as inhibition of protein kinase C (PKC) activity induced by phorbol 12-myristate 13-acetate treatment, inhibition of tyrosine protein kinase activity, and inhibition of arachidonic acid (AA) metabolism. Treatment of NIH 3T3 cells with the PKC inhibitor staurosporine, the tyrosine kinase inhibitor herbimycin A, and the AA metabolism inhibitor quinacrine induces apoptotic cell death. These results suggest that, in some immortalized and transformed cells, blocking the cellular signal transduction might trigger the induction of apoptosis.
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PMID:Curcumin induces apoptosis in immortalized NIH 3T3 and malignant cancer cell lines. 884 27


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