1
|
Abstract
This article reviews the effects of lead on genetic systems in the context of lead's various other toxic effects and its abundance and distribution in the environment. Lead is perhaps the longest used and best recognized toxic environmental chemical, yet it continued be used recklessly until only very recently. Lead is thus a lesson in the limitations and strengths of science, human conscience and common sense. Lead has been tested and found to be capable of eliciting a positive response in an extraordinarily wide range of biological and biochemical tests; among them tests for enzyme inhibition, fidelity of DNA synthesis, mutation, chromosome aberrations, cancer and birth defects. It reacts or complexes with many biomolecules and adversely affects the reproductive, nervous, gastrointestinal, immune, renal, cardiovascular, skeletal, muscular and hematopoietic systems as well as developmental processes. It is likely that lead is a selective agent that continues to act on and influence the genetic structure and future evolution of exposed plant and animal populations.
Collapse
Affiliation(s)
- F M Johnson
- Toxicology Operations Branch, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| |
Collapse
|
2
|
Abstract
The mutagenic, carcinogenic and teratogenic effects of vanadium and its compounds are reviewed. It is concluded that vanadium is not clastogenic and only weakly mutagenic; it has marked mitogenic activity affecting the distribution of chromosomes during mitosis and possibly causing aneuploidy. The few positive data on effects of vanadium during development leave it open whether direct effects on the embryo of fetus or physiological disturbances in the mother are responsible. No data exist indicating that vanadium is carcinogenic in animals or man, but since it interferes with mitosis and chromosome distribution, the possibility that vanadium might be carcinogenic under certain conditions cannot be dismissed offhand.
Collapse
Affiliation(s)
- A Léonard
- Teratogenicity and Mutagenicity Unit, Catholic University of Louvain, Brussels, Belgium
| | | |
Collapse
|
3
|
Sheu CW, Rodriguez I, Lee JK. Proliferation and morphological transformation of BALB/3T3 cells by a prolonged treatment with sodium orthovanadate. Food Chem Toxicol 1992; 30:307-11. [PMID: 1628866 DOI: 10.1016/0278-6915(92)90008-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BALB/3T3 mouse embryo cells were used to study the effect of sodium orthovanadate on cell proliferation and morphological transformation. In the presence of the chemical (0.25-1.0 micrograms/ml), the cells continued to proliferate after the cultures were confluent. However, contact-inhibited growth was resumed after removal of the chemical from the culture medium. Continued exposure of the cells to the chemical for 4 wk led to the production of numerous foci consisting of morphologically transformed cells. In contrast, as in vitro transformation assay with a 48-hr treatment protocol followed by 4 wk of incubation without the chemical produced negative results. To test the stability of the transformed foci that were produced on prolonged exposure, we isolated 20 foci with distinctly transformed characteristics from treated cultures and grew them in medium without orthovanadate. 15 isolates gradually reverted to contact-inhibited growth and five maintained the transformed phenotype through ten serial subcultures. The results show that the majority of the transformed foci from the orthovanadate-treated culture failed to maintain transformed characteristics in the absence of the chemical. However, a small fraction of the foci appeared to be altered permanently and exhibited a transformed phenotype in the absence of the chemical.
Collapse
Affiliation(s)
- C W Sheu
- Genetic Toxicology Branch, Food and Drug Administration, Washington, DC 20204
| | | | | |
Collapse
|
4
|
Abstract
Cancer epidemiology has identified several metal compounds as human carcinogens. Recent evidence suggests that carcinogenic metals induce genotoxicity in a multiplicity of ways, either alone or by enhancing the effects of other agents. This review summarizes current information on the genotoxicity of arsenic, chromium, nickel, beryllium and cadmium compounds and their possible roles in carcinogenesis. Each of these metals is distinct in its primary modes of action; yet there are several mechanisms induced by more than one metal, including: the induction of cellular immunity and oxidative stress, the inhibition of DNA metabolism and repair and the formation of DNA- and/or protein-crosslinks.
Collapse
Affiliation(s)
- E T Snow
- Nelson Institute of Environmental Medicine, New York University Medical Center, Tuxedo 10987
| |
Collapse
|
5
|
Abstract
This article reviews approximately 700 results reported in the literature with 32 chromium compounds assayed in 130 short-term tests, using different targets and/or genetic end-points. The large majority of the results obtained with Cr(VI) compounds were positive, as a function of Cr(VI) solubility and bioavailability to target cells. On the other hand, Cr(III) compounds, although even more reactive than Cr(VI) with purified nucleic acids, did not induce genotoxic effects in the majority of studies using intact cells. Coupled with the findings of metabolic studies, the large data-base generated in short-term test systems provides useful information for predicting and interpreting the peculiar patterns of Cr(VI) carcinogenicity.
Collapse
Affiliation(s)
- S De Flora
- Institute of Hygiene and Preventive Medicine, University of Genoa, Italy
| | | | | | | |
Collapse
|
6
|
Abstract
The activities of vanadium oxide (V2O3), vanadyl sulfate (VOSO4) and ammonium metavanadate (NH4VO3) in inducing sister chromatid exchange (SCE) and chromosomal aberrations (CAb) were assayed in Chinese hamster ovary cells. The toxic concentrations (TC50) for these compounds were found to be 25, 23 and 16 micrograms elemental vanadium/ml, respectively. At does 1/50-1/4 TC50, vanadium compounds were able to induce significant increases (P less than 0.01) in the SCE frequency with or without the addition of rat hepatic S9 mix. These compounds also induced CAb in the cells at doses closely equivalent to the TC50.
Collapse
Affiliation(s)
- J Owusu-Yaw
- Food Science and Human Nutrition Department, University of Florida, Gainesville 32611
| | | | | | | |
Collapse
|
7
|
Babich H, Goldstein SH, Borenfreund E. In vitro cyto- and genotoxicity of organomercurials to cells in culture. Toxicol Lett 1990; 50:143-9. [PMID: 2309233 DOI: 10.1016/0378-4274(90)90004-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The sequence of cytotoxic effects for a series of mercury compounds to the BG/F epithelioid cells derived from fin tissue of bluegill sunfish was phenyl mercuric chloride greater than methyl mercuric chloride greater than ethyl mercuric chloride much greater than mercuric chloride. This sequence of in vitro cytotoxicity was similar to that observed in a 48-h LC50 in vivo acute toxicity assay with rainbow trout. Using induction of micronuclei as an indicator of genetic damage, the organomercurials, but not mercuric chloride, were noted to be clastogenic to the BG/F cells.
Collapse
Affiliation(s)
- H Babich
- Laboratory Animal Research Center, Rockefeller University, New York, NY 10021
| | | | | |
Collapse
|
8
|
Swierenga SH, Marceau N, Katsuma Y, French SW, Mueller R, Lee F. Altered cytokeratin expression and differentiation induction during neoplastic transformation of cultured rat liver cells by nickel subsulfide. Cell Biol Toxicol 1989; 5:271-86. [PMID: 2480838 DOI: 10.1007/bf01795356] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Rat liver T51B cells were maintained in the presence of low concentrations of Ni(II) derived from alpha Ni3S2 for 3-15 months in culture in order to monitor cytokeratin, differentiation, and transformation patterns. Nickel exposures caused irreversible, heritable juxtanuclear aggregates of cytokeratin CK55, which increased in size and complexity with prolonged nickel exposure, eventually resembling Mallory bodies and expressing glutamyltransferase. Altered cytokeratin expression was accompanied by induction of differentiation, with markers of both bile ductular cells and hepatocytes, such as induction of cytokeratin polypeptides CK39 and CK49, cell morphology, and cytokeratin filament network changes; whereas control cultures similarly maintained for long periods in culture remained unchanged. Altered cytokeratin expression was also accompanied by acquisition of transformation markers--loss of density dependence, progression toward calcium independence, and (benign) growth in nude mice. Observed cytokeratin aberrations may be a factor in nickel carcinogenesis, in view of the known affinity of the metal for cellular structural proteins, especially keratin, which play a role in maintenance of cell behavior.
Collapse
Affiliation(s)
- S H Swierenga
- Drugs Directorate, Health and Welfare, Canada, Ottawa
| | | | | | | | | | | |
Collapse
|
9
|
Thompson ED, McDermott JA, Zerkle TB, Skare JA, Evans BL, Cody DB. Genotoxicity of zinc in 4 short-term mutagenicity assays. Mutat Res 1989; 223:267-72. [PMID: 2662005 DOI: 10.1016/0165-1218(89)90119-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The genotoxicity of zinc was examined in 4 short-term mutagenicity assays. Zinc acetate produced dose-related positive responses in the L5178Y mouse lymphoma assay and an in vitro cytogenetic assay with Chinese hamster ovary cells, but was negative in the Salmonella mutation assay and did not induce unscheduled DNA synthesis in primary cultures of rat hepatocytes. Zinc-2,4-pentanedione produced frameshift mutations in Salmonella tester strains TA1538 and TA98, but did not induce unscheduled DNA synthesis in primary cultures of rat hepatocytes. The effect of ligand binding of zinc in the in vitro test systems is discussed.
Collapse
Affiliation(s)
- E D Thompson
- Procter and Gamble Company, Miami Valley Laboratories, Cincinnati, OH 45239-8707
| | | | | | | | | | | |
Collapse
|
10
|
Abstract
The toxicity and carcinogenicity of nickel compounds are considered in three broad categories: (1) systemic toxicology, (2) molecular toxicology, and (3) carcinogenicity. The systemic toxicity of nickel compounds is examined based upon human and animal studies. The major organs affected are discussed in three categories: (1) kidney, (2) immune system, and (3) other organs. The second area of concentration is molecular toxicology, which will include a discussion of the chemistry of nickel, its binding to small and large molecular weight ligands, and, finally, its cellular effects. The third major area involves a discussion of the carcinogenicity and genotoxicity of nickel compounds. This section focuses on mechanisms, using studies conducted in vivo and in vitro. It also includes a discussion of the assessment of the carcinogenicity of nickel compounds.
Collapse
Affiliation(s)
- T P Coogan
- Institute of Environmental Medicine, New York University Medical Center, New York
| | | | | | | |
Collapse
|
11
|
Abstract
The genotoxic interaction of metals, which are common environmental contaminants, was studied in cultured hepatocytes. Freshly isolated rat hepatocytes were exposed to concentrations of cadmium, copper, silver and lead salts ranging from non-cytotoxic to moderately cytotoxic (as determined by LDH release), and the incorporation of [3H]thymidine into the DNA, as a measure of repair synthesis, was followed. In addition, the uptake of metals by the nuclear fraction was determined using Inductively Coupled Plasma/Mass Spectrometry or atomic absorption spectrophotometry. The evaluation of binding of 109Cd to the DNA in situ was also attempted. It was observed that after a 20 h exposure period, all the metals investigated were found in the nuclear fraction of hepatocytes, with Ag apparently being accumulated less efficiently. In parallel, Cd (0.18 to 1.8 microM) and Cu (7.9 to 78.5 microM) consistently produced a statistically significant stimulation of [3H]thymidine incorporation into the DNA, in the presence or absence of hydroxyurea while Ag was active only at the highest concentration tested (18.5 microM). In contrast, Pb failed to induce a UDS response at the levels used. Moreover, exposure of hepatocytes to 1.8 microM 109CdCl2 for 20 h led to a DNA binding ratio of 0.98 +/- 0.23 ng Cd/micrograms DNA. The present results support the view that the nucleus may be an important target organelle for metal toxicity.
Collapse
Affiliation(s)
- F Denizeau
- Department of Chemistry, Université du Québec à Montreéal, Canada
| | | |
Collapse
|
12
|
Biggart NW, Murphy EC. Analysis of metal-induced mutations altering the expression or structure of a retroviral gene in a mammalian cell line. Mutat Res 1988; 198:115-29. [PMID: 2832750 DOI: 10.1016/0027-5107(88)90047-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Carcinogenic metal compounds, with the exception of chromium(VI), have been found to be poorly mutagenic in both prokaryotic and mammalian cell mutagenesis assays, yet they are clearly clastogenic (Hansen and Stern, 1984). Thus, the role of metals as initiators in carcinogenesis has been difficult to delineate. In an effort to develop a model system capable of assaying DNA damage caused by carcinogenic metals, we have investigated the role of NiCl2, CdCl2, Na2CrO4, and NMU in a murine sarcoma virus-infected mammalian cell line in which expression of the retroviral v-mos gene is growth-temperature regulated. This cell line, designated 6m2, contains a single-copy, stably integrated, mutant Moloney murine sarcoma virus DNA (designated MuSVts110) and is temperature sensitive for morphological transformation due to a conditionally defective viral RNA-splicing event that in turn regulates expression of the viral transforming gene. Mutations affecting the viral DNA in 6m2 cells can be detected if these alterations lead to changes in the structure or expression of the transforming protein encoded by the MuSVts110 v-mos gene. Analysis of the viral proteins from 6m2 'revertant' cell lines (as defined by reversion to the transformed phenotype at all growth temperatures) selected after treatment with the above agents showed that NiCl2, NMU, and Na2CrO4 each induced a different yet specific type of mutation. NiCl2 and NMU each altered the temperature sensitivity of viral RNA splicing, possibly due to base substitution mutations, but did so to distinctly different extents. Na2CrO4 affected the structure of the viral proteins by inducing what appear to be short frameshift mutations that resulted in the temperature-dependent translation of a novel virus-encoded transforming protein, P100gag-mos. CdCl2 also induced frameshift mutations but, in one case, induced a mutation which may result from a deletion of about 300 bases within the MuSVts110 DNA.
Collapse
Affiliation(s)
- N W Biggart
- Department of Tumor Biology, University of Texas M.D. Anderson Hospital and Tumor Institute, Houston 77030
| | | |
Collapse
|
13
|
Dose-response studies of nickel-induced morphological transformation of Syrian hamster embryo fibroblasts. Toxicol In Vitro 1988; 2:303-7. [DOI: 10.1016/0887-2333(88)90050-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/1987] [Revised: 03/07/1988] [Indexed: 11/22/2022]
|
14
|
Biggart NW, Gallick GE, Murphy EC. Nickel-induced heritable alterations in retroviral transforming gene expression. J Virol 1987; 61:2378-88. [PMID: 3037102 PMCID: PMC255651 DOI: 10.1128/jvi.61.8.2378-2388.1987] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Determination of the mutagenic effects of carcinogenic nickel compounds has been difficult because, like many metals, nickel is poorly or nonmutagenic in procaryotic mutagenicity assays. We attempted to characterize nickel-induced genetic lesions by assessing the effect of nickel chloride on the conditionally defective expression of the v-mos transforming gene in normal rat kidney cells infected with the Murine sarcoma virus mutant ts110 (MuSVts110) retrovirus. MuSVts110 contains an out-of-frame gag gene-mos gene junction that prevents the expression of the v-mos gene at the nonpermissive temperature (39 degrees C). In MuSVts110-infected cells (6m2 cells) grown at 33 degrees C, however, this defect can be suppressed by a splicing event that restores the mos reading frame, allowing the expression of a gag-mos fusion protein which induces the transformed phenotype. The capacity to splice the viral transcript at 33 degrees C, but not at 39 degrees C, is an intrinsic property of the viral RNA. This property allowed us to target the MuSVts110 genome using a positive selection scheme whereby nickel was used to induce genetic changes which resulted in expression of the transformed phenotype at 39 degrees C. We treated 6m2 cells with NiCl2 and isolated foci consisting of cells which had reverted to the transformed phenotype at 39 degrees C. We found that brief nickel treatment increased the reversion frequency of 6m2 cells grown at 39 degrees C sevenfold over the spontaneous reversion frequency. The nickel-induced revertants displayed the following heritable characteristics: They stably maintained the transformed phenotype at 39 degrees C; unlike the MuSVts110 RNA in 6m2 cells, the nickel-induced revertant viral RNA could be spliced efficiently at 39 degrees C; as a consequence of the enhanced accumulation of spliced viral RNA, the nickel-induced revertants produced substantial amounts of the transforming v-mos protein P85gag-mos at 39 degrees C; the nickel-induced revertant P85gag-mos serine kinase, like the parental 6m2 P85gag-mos kinase, was found to be rapidly inactivated at 39 degrees C; however, in the nickel-induced revertants, overproduction of P85gag-mos allowed the transformed state to be maintained; and even though viral RNA processing was much changed, no rearrangements of the viral DNA in the nickel-induced revertant cells were detected by partial restriction analysis.
Collapse
|
15
|
Abstract
Inorganic metals and minerals for which there is evidence of carcinogenicity are identified. The risk of cancer from contact with them in the work place, the general environment, and under conditions of clinical (medical) exposure is discussed. The evidence indicates that minerals and metals most often influence cancer development through their action as cocarcinogens. The relationship between the physical form of mineral fibers, smoking and carcinogenic risk is emphasized. Metals are categorized as established (As, Be, Cr, Ni), suspected (Cd, Pb) and possible carcinogens (Table 6), based on the existing in vitro, animal experimental and human epidemiological data. Cancer risk and possible modes of action of elements in each class are discussed. Views on mechanisms that may be responsible for the carcinogenicity of metals are updated and analysed. Some specific examples of cancer risks associated with the clinical use of potentially carcinogenic metals and from radioactive pharmaceuticals used in therapy and diagnosis are presented. Questions are raised as to the effectiveness of conventional dosimetry in accurately measuring risk from radiopharmaceuticals.
Collapse
|
16
|
Biggart NW, Costa M. Assessment of the uptake and mutagenicity of nickel chloride in salmonella tester strains. Mutat Res 1986; 175:209-15. [PMID: 3537781 DOI: 10.1016/0165-7992(86)90056-4] [Citation(s) in RCA: 68] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
NiCl2 was examined for mutagenic activity in a number of Salmonella tester strains. Conditions were established where there was substantial uptake of the metal into the bacterial cells. However, even when the metal ion was apparently taken up, as determined by metal association with cells, there was a lack of mutagenic activity. These results suggest that nickel is unable to induce basepair or frameshift mutations in Salmonella tester strains and are discussed in relationship to the low binding affinity of Ni(II) for DNA.
Collapse
|