Download Characterization of Mouse Cell Lines Resistant to Nickel(H) Ions1

[CANCER RESEARCH 48, 6850-6854, December 1, 1988]
Characterization of Mouse Cell Lines Resistant to Nickel(H) Ions1
Xin Wei Wang,2 Richard J. Iinbra, and Max Costa
Institute of Environmental Medicine, New York University Medical Center. New York, New York 10016
ABSTRACT
BALB/C-3T3 cells have been isolated that are resistant to NiCl2. The
degree of resistance is directly dependent upon the Ni<'1; exposure
concentration and ranges from 6- to 11-fold. Resistance to NiCl2 does not
appear to be due to alterations in cellular uptake, since the entry of Ni(II)
into wild-type or resistant cells was similar. Resistance does not appear
to be due to alterations in metallothionein expression. Resistant cells
have a high incidence of heterochromatic abnormalities involving fusions
at the centromeres as determined by C-banding and in situ hybridization
utilizing a cloned mouse satellite DNA probe. Cells retain nickel resist
ance for many generations in the absence or presence of NiClj selection;
however, with time in the absence of NiCI2, the level of resistance
decreases. This loss of resistance is associated with a decreased number
of centromeric fusions. These results indicate that nickel resistance is
involved with changes in heterochromatin and suggest that this effect of
nickel on heterochromatin may be important as an early step in nickel
carcinogenesis.
INTRODUCTION
Certain nickel compounds are complete and potent carcino
gens, inducing a wide variety of tumors in experimental ani
mals, whereas other nickel compounds lack carcinogenic activ
ity (1-4). This carcinogenic potency appears to be related, in
part, to the bioavailability of ionic nickel (5, 6). Investigations
of the mechanism of nickel carcinogenesis have revealed several
interesting properties of these agents. Carcinogenic nickel com
pounds exhibit little activity in gene mutation assays but are
capable of inducing DNA damage in the form of strand breaks
and DNA-protein complexes (7-10). Chromosomal damage is
the most striking effect observed in nickel-treated cells, espe
cially the selective damage that occurs in heterochromatic re
gions of mouse and Chinese hamster chromosomes (11-13).
Several hypotheses have been proposed as to why nickel ions
appear to damage heterochromatin selectively: (a) the perinuclear location of heterochromatin in the interface nucleus makes
this the first site of nickel interaction (14); (b) heterochromatin
may contain more sites that favor nickel(II) binding (15); (c)
there is less DNA repair in transcriptionally inactive hetero
chromatic regions (16).
These and perhaps other factors may play a role in explaining
the selective damage in heterochromatin caused by nickel ions.
Two types of heterochromatin have been described based upon
their transcriptional activity (17). Constitutive heterochromatin
is considered to be permanently genetically inactive, while
facultative heterochromatin can exhibit transcriptional activity
(18). However, recent studies have shown that the constitutive
heterochromatin in the X chromosome of vole fibroblast cell
lines exhibits similar genetic activity as the euchromatic regions
of this chromosome (19). In other tissues of the vole, the
constitutive heterochromatin may be genetically inactive but,
Received 3/24/88; revised 6/7/88, 8/16/88: accepted 8/29/88.
The costs of publication of this article were defrayed in part by the payment
of page charges. This article must therefore be hereby marked advertisement in
accordance with 18 I'.S.C. Section 1734 solely to indicate this fact.
1This work is supported by Grant CA43070 of the National Cancer Institute
and Grant R813140-010 of the United States En\ironmental Protection Agency.
; To whom requests for reprints should be addressed, at Institute of Environ
mental Medicine. New York University Medical Center. 550 First Avenue, New
York. NY 10016.
as has been shown in these fibroblasts, it has the potential to
become genetically active. It is possible that the interaction of
nickel with heterochromatin may cause activation of transcrip
tion in constitutive or facultative heterochromatin. Nickel ions
have been shown to affect DNA-protein interactions which
could alter transcriptional activity (9, 10).
In view of the selective acute effects of NiCh on heterochro
matin, we examined whether cells that become resistant to
NiCl2 exhibit heterochromatic abnormalities. We demonstrate
that mouse cell lines, continuously incubated in the presence of
nickel chloride, acquire resistance to nickel and that this resist
ance is associated with a high degree of centromeric fusions
involving heterochromatin. When resistant cells are incubated
in the absence of nickel chloride, resistance to nickel is main
tained for many cell generations, but some loss of nickel resist
ance occurs and is associated with a loss of heterochromatin
abnormalities. These studies demonstrate that nickel-induced
effects in heterochromatic DNA are relatively stable and are
related to the level of nickel resistance. These results, combined
with previous reports, provide further evidence that nickel ions
selectively interact with heterochromatin.
MATERIALS
AND METHODS
Chemicals. Nickel chloride was purchased from Alfa Inorganics
(Danvers, MA). Dulbecco's modified Eagle's medium, newborn calf
serum, and penicillin-streptomycin solution were supplied by Hazelton
Research Products, Inc. (Denver, PA). L-Glutamine. pancreatic ribonuclease A. and Giemsa stain were from Sigma Chemical Co. (St.
Louis. MO). 6'NiCl2 was from New England Nuclear (Boston, MA).
Cell Culture. BALB/C-3T3 mouse fibroblasts obtained from the
American Type Culture Collection were grown in monolayer in DM EM
containing 10% newborn calf serum, 2 mM L-glutamine, 100 units/ml
of penicillin, and 100 Mg/ml of streptomycin. The cultures were main
tained at 37"C in a humidified atmosphere of 95% air:5% CO2. Cells
were routinely grown to 60 to 80% confluency, trypsinized, and replated
at a 1:4 dilution.
Selection for Nickel-resistant Sublines. About 1 x IO6 BALB/C-3T3
cells were plated in a 100-mm-diameter tissue culture dish (Corning
Plastics) containing 10 ml of medium and 10 /JM NiClj. Medium
containing NiCI2 was replaced every 3 to 4 days for 1 mo. At the end
of this time, the concentration of NiCl2 was increased in 10 MM
increments, monthly, up to 50 MM.Surviving colonies were isolated,
and one clone (designated B50) was used in further experiments. Cloned
B50 cells were again selected in medium containing 60 MMand, subse
quently, in 100 MMand 200 MMNiCI:. Resistant cells were isolated and
designated B60, B100. or B200, respectively. Each selection process
was continued for 1 to 2 mo. Nickel-resistant cells were passaged as
described for the parent BALB/C-3T3 cells, except that the cultures
were maintained in medium containing the designated concentration
ofNiClj.
Chromosome Preparation and Staining. Exponentially, growing cells
were treated with Colcemid at a final concentration of 0.04 Mg/ml for
2 h. Mitotic cells were obtained by gentle pipetting of the overlying
medium, and cells were collected by centrifugation at 1000 rpm. Mitotic
cells were treated with 0.075 M KC1 for 8 min at room temperature,
fixed in methanol:acetic acid (3:1), spread on a glass microscope slide,
and air dried. Fixed chromosome preparations were either stained with
3% Giemsa to analyze chromosome number or C-banded to visualize
heterochromatic DNA (20).
Colony-forming Activity. Cell survival was determined by plating 500
6850
Downloaded from cancerres.aacrjournals.org on June 15, 2017. © 1988 American Association for Cancer Research.
HETEROCHROMATIC
CHANGES IN NICKEL-RESISTANT
wild-type or nickel-resistance cells into 60-mm-diameter tissue culture
dishes and treating with various concentrations of metal ions for either
24 h or continuously. Colonies were allowed to form over a 7-14 day
time interval, then fixed with ethanol, and stained with 0.5% crystal
violet. The survival was calculated by counting the number of colonies
per dish, expressing this number as a function of cells plated in each
dish, and normalizing for growth in the absence of metal ions.
Cellular Uptake of "NiClj. Wild-type and nickel-resistant cells were
treated with NiCh containing 1 MCi/ml of 63NiCl2(see Table 1, legend).
At selected time intervals, cells were washed twice with ice-cold saline
containing 1 mM EDTA and removed from the culture dishes by
trypsinization. The cell number was determined by using a Coulter
particle counter, and the cellular uptake of "Ni2+ was determined by
measuring the radioactivity with a liquid scintillation counter.
Dot blot, Southern, and northern blot hybridization analyses for
alterations in metallothionein DNA and mRNA or satellite DNA were
performed as previously described (21). In situ hybridization with a
mouse satellite DNA probe was performed as previously described (22).
RESULTS
Properties of Nickel-resistant Cells. Four nickel-resistant mu
tant cell lines have been isolated by serial culture of mouse
fibroblasts. BALB/C-3T3 cells were selected in the presence of
50, 60, 100, or 200 pM NiCl2 for at least 1 mo each and
designated as B50, B60, B100, or B200, respectively. The
relative plating efficiency of these resistant cell lines, following
treatment for 24 h with various concentrations of NiCl2, was
compared to the parental BALB/C-3T3 cells (Fig. 1). All of the
mutant cells were more resistant to the toxic affects of NiCl2
than the parental BALB/C-3T3 cells, and each clone showed a
dose-dependent increase in resistance that correlated with the
level of NiCl2 used for their selection; i.e., B200 > B100 > B60
> B50 > BALB/C-3T3. The LC503values for 24-h exposure to
NiCl2 in wild-type cells were 100 MM,while those for the nickelresistant cells were: B50, 570 MM(5.7-fold resistant); B60, 660
CELLS
MM(6.6-fold resistant); B100, 1000 MM(10-fold resistant); and
B200, 1100 MM(11-fold resistant). Relative levels of resistance
following continuous treatment with NiCl2 (data not shown)
were similar to those observed using 24-h exposures to NiCl2.
One mechanism for the increased resistance to chemical
agents may involve an alteration in the uptake of the toxic
agent into cells (23, 24). We examined whether nickel uptake
was altered by incubating BALB/C-3T3 or B100 cells for 6 h or
24 h in the presence of 100 MMor 300 MMNiCl2 containing 1
MCi of 63NiCl2 per ml of medium. Table 1 lists the results of
three separate uptake experiments. The data show that both
the parental and resistant B100 cells accumulate equivalent
levels of nickel ions under the conditions tested. Similar results
were obtained in other clones as well. Therefore, resistance of
the B100 cells to NiCl2 is not due to altered uptake of nickel
ions from the medium.
The induction of metallothionein synthesis in response to
cadmium is a mechanism involved with the detoxification of
this metal (25). Southern blot analysis using a 32P-labeled
metallothionein gene probe was used to determine if this gene
was amplified in the mutant cells. No detectable metallothi
onein gene amplification was observed in the nickel-resistant
cells (data not shown), which is consistent with previous reports
that nickel ion does not induce metallothionein (30). Similarly,
metallothionein mRNA levels in wild-type and nickel-resistant
B200 cells were comparable (data not shown).
Chromosome Changes in Nickel-resistant Cells. Chromosome
number was determined by examining chromosome spreads of
cells following Giemsa staining (Table 2). Wild-type BALB/c3T3 cells contain approximately 70 chromosomes per metaphase. All the chromosomes are acrocentric, except for one
metacentric chromosome. The karyotype of the nickel-resistant
cells shows extensive chromosome changes as compared to the
wild-type cells, including a striking increase in centric fusions
that correlates with increased resistance to NiCl2 (Table 2).
Table 1 Uptake 0/"AïC/2 by BALB/C-3T3 or nickel-resistant BlOO Cells
100
Cells were incubated for various times in the presence of 100 I¿M
or 300 uM
NiCl2 containing 1 >iCi/ml of "NiCI2. Following the incubation, the cellular
uptake of "Ni2* was determined as described in "Materials and Methods."
60
Time
of Ni(II)
(pmol/
cells)232.2
10*
(h)624Cell typeHALBBlOOBALBBlOOBALBBlOOBALBBlOO"NiCI2GlM)1001003003001001
ofcontrol10096100101100831001
78.5°222.7
±
126.4872.0
±
276.9882.5
±
1.9483.3
±45
40
¡
CO
20
±281.0400.3
195.92108.0
±
±931.92
100.5 ±1292.5%
1Mean ±SD; values normalized from three individual experiments.
ILI
O
500
CONCENTRATION
1000
NiCI2 (uM)
Fig. 1. Survival of various cell lines in the presence of NiCI2. The cell-plating
efficiency of parental BALB/C-3T3 cells (A) and various nickel-resistant cells
[selected in the presence of 50 (•).60 (D), 100 (•),or 200 /*MNiCI2 (O) for at
least 1 mo and designated as B50, B60, BlOO. and B200. respectivelyl was
determined following treatment for 24 h with various concentrations of NiClj.
Cells show a dose-dependent increase in resistance that correlates with the level
of NiCb selection; i.e.. B200 > BlOO > B60 > B50 BALB/C-3T3. The LC«,of
NiCI2 for the various cell lines is listed in Table 1.
3 The abbreviation used is: LC5o, concentration that reduces cell-plating effi
ciency by 50%.
Table 2 Chromosome analysis of wild-type BALB/c-ÌTÌ
cells and nickelresistant sublines
Chromosome numbers are based on the counts of at least 30 metaphase cells
per line.
No. of centric fuTotal chromosomes/metCell lines
sions/metaphase
aphase
.1°1.3
±
BALB/C-3T3BALB+
NiClj*BALB
100 MM
.21.2±
NiCl2*BALB
+ 250 uM
.11.3±
NiCI2*B50fB100fB200C1.1
+ 500 MM
.92.3±
.57.2±
3.29.6
±
±2.869.772.570.671.763.355.054.65.22.73.34.43.54.74.8
°Mean ±SD.
* BALB/C-3T3 cells were treated with NiCI2 for 24 h.
c Nickel-resistant cells were adapted for at least 2 mo to medium containing
50. 100, or 200 MMNiCl2 and expressed as B50, BlOO, B200, respectively.
6851
Downloaded from cancerres.aacrjournals.org on June 15, 2017. © 1988 American Association for Cancer Research.
HETEROCHROMATIC
CHANGES IN NICKEL-RESISTANT
Increased centric fusions were not observed in cells treated
acutely with various concentrations of NiCb for up to 24 h
(Table 2). In addition to centric fusions, total chromosome
number decreased by 5 to 10 chromosomes per metaphase as
cells became increasingly resistant to NiCl2.
The heterochromatic centromeres of mouse cells are com
posed of highly repetitive satellite DNA. In order to determine
if these heterochromatic regions are involved in the centric
fusions, chromosomes were examined by C-banding (Fig. 2).
Only the centromeres stain C-band positive in the parental
BALB/C-3T3 cells (Fig. 2A). Similarly, the centromeres in B200
cells are C-band positive, including the regions of centric fusion.
In addition, dispersed throughout the chromosomal arms of
B200 cells are C-banding regions, suggesting either that re
arrangements of centromeric, satellite DNA occurred in these
cells or that nickel treatment has induced conversion of nor
mally euchromatic DNA into a heterochromatic state (Fig. 2B).
In order to distinguish between these two possibilities, we
identified regions containing satellite DNA by in situ hybridi
zation utilizing a cloned mouse satellite DNA probe (Fig. 3).
Results showed that the C-band-positive centromeres and cen
tric fusions consist of satellite DNA. However, the C-bandpositive material observed in the chromosomal arms did not
hybridize to the satellite DNA probe. Therefore, the C-bandpositive regions in the chromosomal arms do not appear to be
due to rearranged satellite DNA.
Stability of the Nickel-resistant Phenotype. B100 cells were
incubated for various time intervals (3 days to 19 wk) in the
absence of NiCl2, then examined for changes in chromosomal
karyotypes and for cell survival following acute nickel exposure.
The LCso for NiCl2 was determined and is expressed as a
function of time following removal of NiCl2 (Fig. 4; LC5o of
wild-type cells is included for comparison). Fig. 4 shows that
nickel resistance of B100 cells appears to slowly decrease with
time following removal of NiCl2, being reduced to one-half after
about 6 wk of incubation in the absence of nickel selection.
This is equivalent to about 40 population doublings. However,
CELLS
B100 cells still retain 4-fold resistance to NiCl2 after about 10
wk. This slow loss of resistance suggests that the resistant
phenotype is relatively stable in the absence of nickel. There
were no significant differences in the doubling time of wildtype or NiCl2-resistant cells.
Fig. 5 shows the distributions of centric fusions in B100 cells
with time following removal of NiCl2. The average number of
centric fusions for the B100 cell line is seven. About 4 centric
fusions per metaphase were retained 11 wk following the re
moval of NiCl2 (40% resistance is retained at this time; see Fig.
4). The number of centric fusions is reduced to 3 after 19 wk in
the absence of NiCl2. In addition, this slow loss in the number
of centric fusions appears to be associated with an increase in
total chromosome number, as shown in Table 3, and with a
progressive loss of nickel resistance. However, the loss of centric
fusion and nickel resistance is not directly proportional.
DISCUSSION
There are numerous reports of cultured mammalian cells that
have developed resistance to cadmium (25-28). This resistance
has been shown to be due to amplification of the metallothionein gene (25, 29). Cadmium-resistant cells also exhibit crossresistance to other metal ions that induce metallothionein;
however, they exhibit only a minimal resistance to nickel ions
which are a poor inducer of metallothionein (30). To our
knowledge, this is the first report showing that mammalian
cells develop resistance to nickel ions (NiCl2). The degree of
resistance is dependent upon the concentration of NiCl2 utilized
for selection of the clones. We were not able to detect amplifi
cation of the metallothionein gene or increased metallothionein
mRNA in the nickel-resistant clones, indicating that metallo
thionein is not directly involved in the nickel resistance.
In the absence of NiCl2, the cells remain nickel resistant for
many generations, although some resistance is lost. A reactive
site of nickel in cells is the heterochromatic regions of chromatin (11-13). It is interesting that nickel resistance is associ-
B
Fig. 2. C-banding of parental BALB/C-3T3
(A) and B200 cell (B) chromosomes. Arrows,
regions of heterochromatic DNA.
6852
Downloaded from cancerres.aacrjournals.org on June 15, 2017. © 1988 American Association for Cancer Research.
HETEROCHROMATIC
CHANGES IN NICKEL-RESISTANT
A
CELLS
B
<oV
Fig. 3. Localization of mouse satellite se
quences to the chromosomes of BALB/C-3T3
(A) and B200 cells (B). Chromosomes of
BALB/C-3T3 cells and B200 cells were hybrid
ized in situ with a tritium-labeled mouse sat
ellite DNA probe labelled by nick-translation
(21). The hybridized sequences were visualized
by autoradiography and by Giemsa staining as
described in "Materials and Methods."
..
",
•¿A
V
1000
i r- 0 Week
r 1.5 Weeks
800
600 -
o
z
os400
-
200 -
NUMBER
2468
TIME AFTER REMOVAL FROM NiC
10
12
(weeks)
OF CENTROMERIC
FUSIONS
PER METAPHASE
Fig. S. Distribution of centromeric fusion in nickel-resistant cells following
removal of NiCl2.
Fig. 4. NiCl2 LC50values in B100 cells and BALB/C-3T3 cells at various times
following removal from NiCh selection.
ated with a high degree of centromeric fusions and also that
any loss of nickel resistance was similarly associated with a loss
of the heterochromatic fusions. Acute exposures of wild-type
cells to NiCb have been shown to produce a high degree of
damage in the heterochromatic centromeric regions (13). How
ever, the centromeric fusions associated with nickel resistance
were not generally observed following acute exposures, al
though other chromosome damage in heterochromatin has been
described (11-13). Dot blot hybridization studies using a mouse
satellite DNA probe indicated that this DNA sequence was not
altered in quantity in the nickel-resistant cells, even though the
total chromosome number decreased in resistant cells. In mouse
Table 3 Stability of centric fusions in BIOOcells following removal from NiCI2
Chromosome numbers are based on the counts of at least 30 metaphase cells
per point.
Incubated time
without NiCh
(wk)0
1.5
5
11
14
19No.
1Mean ±SD.
of centric fusions/metaphase7.2
±3.2"
6.7 ±2.3
6.2 ±1.6
4.1 ±1.7
4.5 ±1.5
3.5 ±1.5Total
chromosomes/metaphase55.0
57.7
60.7
60.0
61.4
60.0
±4.7
±4.5
±4.3
±2.1
±3.7
±4.5
6853
Downloaded from cancerres.aacrjournals.org on June 15, 2017. © 1988 American Association for Cancer Research.
HETEROCHROMATIC
CHANGES IN NICKEL-RESISTANT
cells most of the heterochromatic DNA is made up of highly
repeated satellite DNA sequences. Since nickel has been shown
to interact with heterochromatin in other species that contain
more protein coding sequences in heterochromatin than mouse
cells, this effect may have general importance in nickel carcinogenesis (11-13). The ability of cells to retain nickel resistance
and divide in the presence of nickel while retaining heterochro
matic changes may be early events involved in nickel carcinogenesis. We note that the nickel-resistant cells examined here
exhibit a transformed phenotype including loss of contact in
hibition and growth in soft agar.
The fusion of chromosomes in the centromere is related to
nickel resistance, suggesting that this is a major site of nickel
interaction in intact cells. Evidence is accumulating that the
interaction of nickel with heterochromatin may be important
in its carcinogenesis. Several key examples include the higher
incidence of transformation of male Chinese hamster embryo
cells compared to female cells, since in this species, the long
arm of the X chromosome contains the longest contiguous
region of heterochromatin (31). Recent studies have shown that
4 of 5 of the male nickel-transformed lines exhibit a deletion of
the long arm of the X chromosome as a major aberration and
the only one common to the nickel-transformed lines (31).
These results suggest that nickel may induce the loss of genes
that suppress the transformation of these cells and that these
gene(s) may be located in heterochromatin (31). The ability of
nickel but not many other chemical carcinogens to induce
tumors in the newt is also of interest, since this amphibian has
10 times the amount of DNA of mammalian cells, and most of
this DNA is highly repetitive and heterochromatic (32). Excess
magnesium ions inhibit nickel-induced transformation and car
cinogenesis. They also selectively inhibit nickel-induced damage
in heterochromatin with little inhibition of the damage caused
by nickel in euchromatin (33).
The present study shows that the nickel-induced damage in
heterochromatin can be inherited for a number of cell divisions.
This alteration in heterochromatin may activate the transcrip
tion of protein coding sequences in heterochromatin (19). It
may also lead to aneuploidy which could cause carcinogenesis
by loss of cancer-suppressing genes (34). We have recently
extended our studies of nickel-resistant cells to analysis of
protein changes associated with this resistance. Preliminary
evidence suggests that a M, 44,000 protein with an isoelectric
point of 7.5 is increased in the nickel-resistant cell. This protein
appears to correlate with resistance but is not induced by acute
nickel treatment. Further work is required to understand the
significance of this protein in terms of what role it may play in
the heterochromatic changes observed.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
REFERENCES
1. Costa, M., and Heck. J. D. Perspectives on the mechanism of nickel carci
nogenesis. Adv. Inorg. Biochem.. 6: 285-309. 1985.
2. Leonard. A., Gerber, G. B., and Jacquet, P. Carcinogenicity, mutagenicity,
and teratogenicity of nickel. Mutât.Res., 87: 1-15, 1981.
3. Sunderman, F. W., Jr. Recent progress in nickel carcinogenesis. Toxicol.
Environ. Chem., 8: 235-252, 1984.
4. Sunderman, F. W., Jr., and Maenza, R. M. Comparisons of carcinogenicities
of nickel compounds in rats. Res. Commun. Chem. Pathol. Pharmacol.. 14:
319-330, 1976.
5. Costa, M.. and Mollenhauer, H. M. Carcinogenic activity of paniculate
nickel compounds is proportional to their cellular uptake. Science (Wash.
DC), 209:515-517. 1980.
6. Kasprzak, K. S., Gabryel. P.. and Jarczewska, K. Carcinogenicity of nickel(II)
30.
31.
32.
33.
34.
CELLS
hydroxides and nickel(II) sulfate in Wistar rats and its relation to the in vitro
dissolution rats. Carcinogenesis (Lond.), 4: 275-279, 1983.
Miyaki, M., Akamatsu. N., Ono, T., and Koyama, H. Mutagenicity of metal
cations in cultured cells from Chinese hamster. Mutât.Res., 68: 259-263,
1979.
Biggart, N. W., and Costa, M. Assessment of the uptake and mutagenicity
of nickel chloride in Salmonella tester strains. Mutât.Res., 175: 209-215,
1986.
Patierno, S. R., Sugiyama, M., Basilion, J. P., and Costa, M. Preferential
DNA-protein cross-linking by NiCI2 in magnesium-insoluble regions of frac
tionated Chinese hamster ovary cell chromatin. Cancer Res., 45: 5787-5794,
1985.
Patierno, S. R.. and Costa, M. DNA-protein cross-links induced by nickel
compounds in intact cultured mammalian cells. Chem.-Biol. Interact., 55:
75-91, 1985.
Sen, P., and Costa, M. Induction of chromosomal damage in Chinese hamster
ovary cells by soluble and paniculate nickel compounds: preferential frag
mentation of the heterochromatic long arm of the X-chromosome by carcin
ogenic crystalline NiS particles. Cancer Res., 45:2320-2325, 1985.
Sen, P., and Costa, M. Incidence and localization of sister chromai id ex
changes induced by nickel and chromium compounds. Carcinogenesis
(Lond.), 7: 1527-1533, 1986.
Sen, P., Conway, K., and Costa, M. Comparison of the localization of
chromosome damage induced by calcium chromate and nickel compounds.
Cancer Res., 47: 2142-2147, 1987.
Hsu, T. C. Chromosome structure a possible function of constitutive heter
ochromatin: the bodyguard hypothesis. Genetics, 79: 137-150, 1975.
Eichhorn, G. L. The effect of metal ions on the structure and function of
nucleic acids. Adv. Inorg. Biochem., 3: 1-46, 1981.
Madhani, H. D., Bohr, V. A., and Hanawalt, P. C. Differential DNA repair
in transcriptionally active and inactive proto-oncogenes: c-abl and c-mos.
Cell, 45:417-423, 1986.
Yunis, J., and Yasmineh, W. G. Heterochromatin, satellite DNA, and cell
function. Science (Wash. DC), 174: 1200-1209, 1971.
Sperling, K., Kerem, I!.. Goitein, R.. Kottusch, V., Cedar, H., and Marcus,
M. DNase 1 sensitivity in facultative and constitutive heterochromatin.
Chromosoma (Beri.), 93: 38-42, 1985.
Sperling, K., Kalscheuer, V., and Neitzel, H. Transcriptional activity of
constitutive heterochromatin in the normal Microtus agrestis. Exp. Cell Res.,
773:463-472, 1987.
Deaven, L. L.. and Petersen, D. F. The chromosomes of CHO, an aneuploid
Chinese hamster cell line: G-band, C-band, and autoradiographic analyses.
Chromosoma (Beri.), 41: 129-144, 1973.
Maniatis, T., Fritsch, E. F., and Sambrook, J. (eds.). In: Molecular Cloning:
A Laboratory Manual. Cold Spring Harbor, NY: Cold Spring Harbor Lab
oratory Press, 1982.
Harper, M. E., Ullrich, A., and Saunders, G. F. Localization of the human
insulin gene to the distal end of the short arm of chromosome 11. Proc. Nati.
Acad. Sci. USA, 78:4458-4460, 1981.
Campbell, C. E.. Gravel, R. A., and Worton, R. G. Isolation and character
ization of Chinese hamster cell mutants resistant to the cytotoxic effects of
chromate. Somatic Cell Genet., 7: 535-546, 1981.
Robertson, S. M., Ling, V., and Stanners, C. P. Co-amplification of double
minute chromosomes, multiple drug resistance, and cell surface P-glycoprotein in DNA-mediated transformants of mouse cells. Mol. Cell. Biol., 4:500506, 1984.
Gick, G. G., and McCarty, K. S., Sr. Amplification of the metallothionein-I
gene in cadmium- and zinc-resistant Chinese hamster ovary cells. J. Biol.
Chem., 257:9049-9053. 1982.
Rugstad, H. E., and Norseth, T. Cadmium resistance and content of cad
mium-binding protein in cultured human cell. Nature (Lond.), 257:136-137,
1975.
Rugstad, H. E., and Norseth, T. Cadmium resistance and content of cad
mium-binding protein in two enzyme-deficient mutants of mouse fibroblasts
(L-cells). Biochem. Pharmacol., 27:647-650, 1978.
Hildebrand, C. E., Tobey, R. A., Campbell, E. W., and Enger, M. D. A
cadmium-resistant variant of the Chinese hamster (CHO) cell with increased
metallothionein induction capacity. Exp. Cell, res., 124: 237-246, 1979.
Beach. L. R., and Palmiter, R. D. Amplification of the metallothionein-I
gene in cadmium-resistant mouse cells. Proc. Nati. Acad. Sci. USA, 78:
2110-2114, 1981.
Evans, R. M., Patierno, S. R., Wang, D. S., Cantoni, O., and Costa, M.
Growth inhibition and metallothionein induction in cadmium resistant cells
by essential and non-essential metals. Mol. Pharmacol., 24: 77-83, 1983.
Conway, K., and Costa, M. Transformation of Chinese hamster embryo cells
by nickel yields cell lines with altered heterochromatic staining patterns.
Proc. Am. Assoc. Cancer Res., 29: 117, 1988.
Okamoto, M. Induction of ocular tumor by nickel subsulfide in the Japanese
common newts, Cynopspyrrhogaster. Cancer Res., 47: 5213-5217, 1987.
Conway, K., Wang, X. W., Xu, L., and Costa, M. Effect of magnesium on
nickel-induced genotoxicity and cell transformation. Carcinogenesis (Lond.),
«:1115-1121, 1987.
Oshimura, M., and Barrett, J. C. Chemically induced aneuploidy in mam
malian cells: mechanisms and biological significance in cancer. Environ.
Mutagen., 8: 129-159, 1986.
6854
Downloaded from cancerres.aacrjournals.org on June 15, 2017. © 1988 American Association for Cancer Research.
Characterization of Mouse Cell Lines Resistant to Nickel(II) Ions
Xin Wei Wang, Richard J. Imbra and Max Costa
Cancer Res 1988;48:6850-6854.
Updated version
E-mail alerts
Reprints and
Subscriptions
Permissions
Access the most recent version of this article at:
http://cancerres.aacrjournals.org/content/48/23/6850
Sign up to receive free email-alerts related to this article or journal.
To order reprints of this article or to subscribe to the journal, contact the AACR Publications
Department at [email protected].
To request permission to re-use all or part of this article, contact the AACR Publications
Department at [email protected].
Downloaded from cancerres.aacrjournals.org on June 15, 2017. © 1988 American Association for Cancer Research.