Download Cellular Oncogenes and Human Carcinogenesis

CLIN.CHEM.33/5, 641-646(1987)
Cellular Oncogenes and Human Carcinogenesis
chinlng
J. Der
Experimentalstudiesover the pastdecade have identified30
or so cellular,genes as potential oncogenes. The genetic
eventsthat lead to cellularoncogeneactivationmay result In
the excessiveor inappropriateexpression of the gene, or the
expression of an aberrant gene product. Although the Involvement of these putative cellular oncogenes in human
oncogeflesis has not been proven, the accumulation of
considerable’ experimental evidence strongly implicates
some role of these genes In the malignant process. The
inactivationof certain genetic loci (suppressorgenes) may
also contributeto tumor progression.
Although a genetic basis for the mechanism of human
oncogenesis
has long been assumed, little is known at
present about the precise genetic events responsible
for
malignant transformation. However, recent research developments in several areas of biology have now begun to
define a genetic explanation
for human oncogenesis. The
search for the genetic targets for tumorigenesis
has led to
the identification of a number of cancer genes, or cellular
oncogenes, which have now been implicated in carcinogenesis (1-4). It should be emphasized that a causative involvement of these cellular proto-oncogenes
in carcinogenesis
remains to be established. However, because a considerable
amount of information
has been accumulated
demonstr#{224}ting that many of these cellular oncogenes are altered in
their biological activity, genetic organization,
or expression
in tumor cells, the general belief is that these cellular
oncogenes do contribute to the process of neoplasia. As the
functions of these cellular oncogenes become known, we will
begin to understand how the molecular lesions that activate
these genetic loci contribute to the process of carcinogenesis.
Cellular Homologs of RetroviralOncogenes
Our first glimpse of cellular genes with oncogenic potential has come from studies of the acute transforming
retroviruses (1, 2). These highly oncogenic RNA viruses represent rare isolates from tumors derived from chickens, turkeys, mice, rats, cats, and monkeys. These viruses can
efficiently transform cells in culture and can induce tumors
at high frequency within a short latency period of several
weeks in infected animals. The oncogemcity of these viruses
is a consequence of specific genes (viral oncogenes) present
in each virus (Table 1). These viral oncogenes are not
essential
viral genes, but instead represent transduced
La Jolla Cancer Research Foundation, Cancer Research Center,
10901 N. Torrey Pines Rd., La Jolla, CA 92037.
Presented at the symposium on “Gene Probe Technology: from
Theory to Practice,” San Diego, CA, October 1986.
Received December 29, 1986; accepted February 12,1987.
cellular genes. Thus, each viral oncogene possesses a cellular counterpart
(proto-oncogene) that represents an important normal celiular gene. These cellular proto-oncogenes
are not viral genes in disguise. Cellular proto-oncogenes
represent well-conserved genes, in both structure and function. Each appears to be present in all vertebrate
species,
and at least some are found in invertebrates,
including
yeast, Drosophila, and Dictylostelium
(5-7). Additionally,
virtually all cellular proto-oncogenes
are expressed during
normal growth and development,
encoding for proteins
similar to those produced by their viral counterparts. Presently, the exact role of these cellular genes in normal cells is
not known. Because they represent such well-conserved
genes, presumably they must play an integral role in
normal cell growth and differentiation.
By virtue of their
tendency to transduce cellular sequences, the highly oncogenic retroviruses
have unveiled at least 20 or so cellular
genes that represent potential cellular oncogenes.
Detection of Cellular Transforming Genes by Transfection
A second avenue of research that has resulted in the
unveiling of activated cellular oncogenes comes from genetransfer studies (3,4). The method for detecting biologically
active transforming
genes in cellular DNA is based on the
experiments
of Hill and Hillova (8), who demonstrated
the
transfection
of chicken embryo fibroblasts with DNA from
Rous sarcoma virus-transformed
rat cells. These experiments suggested the possibffity of searching for cellular
oncogenes by the DNA-transfer
technique. Subsequent
Table 1. VIral Oncogenes of Acute Transforming
Retrovlruses
Viral
src
fps
fes
yes
fms
mos
Rous sarcoma virus
Fujinami sarcoma virus
Snyder-Thellenfelinesarcomavirus
Y73 sarcoma virus
McDonough felIne sarcoma virus
Moloney murinesarcoma virus
Ha-ras
Ki-ras
sis
myc
esM,B
myb
Harveymurinesarcoma virus
Kirsten murine sarcomavirus
Myek,cytomatosls virus strain MC29
Avian erythroblastosls virus
Avian myeloblastosis virus
abi
rel
ros
fos
raf
Abelson leukemia virus
Reticuloendotheliosis virus strain T
UR2 aviansarcomavirus
FBJ osteosarcoma virus
3611 murine sarcoma virus
Simiansarcomavirus
chicken
chicken
cat
chicken
cat
mouse
rat
rat
monkey
thicken
thicken
chicken
mouse
turkey
thicken
mouse
mouse
CLINICALCHEMISTRY, Vol. 33, No. 5, 1987 641
studies have utilized NIH 3T3 mouse cells as recipients
because, in contrast to most cell lines, NIH 3T3 cells are
capable of stable integration of exogenous DNA with relatively high efficiencies. The biologic activity of tumor DNA,
detected by transfection of NIH 3T3 cells, has led to the
identification and isolation of transforming
genes that are
activated in a large variety of animal and human neoplasms. Although DNA from normal cells lacks detectable
transforming activity, DNA from many different tumor cells
induces transformation of NIH 3T3 cells with high efficiencies. These observations suggest that the development of
many neoplasms
involves dominant genetic alterations,
leading to the activation of transforming genes that are
detectable by their biologic activity in the transfection
assay.
Table 2 summarizes some of the activated cellular oncogenes detected in the NIH 3T3 transfection assay. Typically,
10-25% of tumor DNAs assayed are positive in the transfection assay; of these, approximately 90% represent activated
cellular homologs of the viral ras genes (9). In addition to
cellular rca activations, several other transfection-detected
activated genes have been identified previously as cellular
homologs of retroviral
oncogenes (ros and raf-1) (10-12),
while the remaining activated transforming
genes represent
novel cellular oncogenes (13-20). Except for the repeated
detection of activated ras in human and rodent tumors, or
the multiple detection of neu activation in rodent glio- and
neuroblastomas (19), the remaining cellular genes active in
the transfection assay have been identified in only one or a
few tuniors. Consequently, the significance of these genes to
tumorigenesis is uncertain because of their limited association with tumor formation.
The presence of activated ras genes in human tumors was
first identified in a human bladder carcinoma (Ha-ras) and a
human lung carcinoma (Ki-ms) cell lines (21-23). Subsequently, a third activated ras gene, N-ms, was detected in a
human neuroblastoma cell line (24-25a). Further studies
have now identified activated ms genes in a wide variety of
human neoplasms, including carcinomas, sarcomas, leukemias, and lymphomas (26, 27). The variety of neoplastic
cells is represented by both established cell lines and
primary tumor isolates, demonstrating that the activation
of cellular ma genes is not a consequence of in vitro
manipulation.
Although the presence of a specific activated rca gene does
not correlate
absolutely with a specific tumor, several
Table 2. Transfectlon-Detected Cellular Oncogenes
from NIH 3T3 Cells
Gene
Ha-ras
Ki-ras
N-ras
OrigIn
Human and rodent carcinoma
Human and rodent carcinoma, sarcoma, leukemia,
lymphoma and others
Human and rodent carcinoma, sarcoma, leukemia,
lymphoma and others
rat-i
ros
B-Iym
met
me!
Human stomach cancer, glioblastoma
Human mammary carcinoma
Human and avian B cell lymphoma
trk
ret
Human coloncarcinoma
Human T-cell lymphoma
r70u
Rodent neuroblastoma, glioblastoma
Human diffuse B-cell lymphoma
Human mammary carcinoma
db!
mas
Human osteosarcoma,chemicallytransformed
Human melanoma
642 CLINICAL CHEMISTRY, Vol. 33, No. 5, 1987
general tendencies can be observed. First, although Ha-ma
activation has been routinely associated with rodent carcinomas, only a few have been detected in human tumors.
Second, activated Ki-ras sequences have been identified in a
wide variety of human tumors, with a frequent association
with lung and colon carcinomas. Finally, N-ma activation
has also been detected in a range of human tumors, but
especially with acute myelogenous leukemias.
In several cases where an activated ma gene was detected
in a tumor isolate, normal cellular DNA isolated from the
same patient lacked any detectable activity in the transfection assay (28-30). These results suggest that ma gene
activation is a consequence of somatic mutation rather than
germ-line mutations. Additionally, the presence of an activated ma gene in the tumor cells would imply a role in
tumor development.
In addition to its common association with human tomore, ms activation has also been described in a number of
experimental rodent systems (31-33). In a study by Barbacid and colleagues, 85% of female rats treated with methylnitrosomethylurea
developed mammary carcinomas
(32).
Transfection analysis of the resulting tumor DNAS revealed
the activation of a Ha-ma gene in 100% of the positive
tumors. Similar results were observed in the other studies
(31,33). Thus the treatment of animals with a specific agent
results in the induction of the same neoplasm, and the
activation of a specific rca gene.
At present, the exact involvement of rca activation in
tumor formation is unclear. However, the frequent activation of ma genes in a wide variety of rodent and human
tumors would certainly provide strong evidence for some
contribution of these genes in tumor development.
Oncogene
Activation and Human Carcinogenesis
What is the evidence that cellular oncogenes are actually
involved in human carcinogenesis? What are the molecular
events that result in their activation? At present, the
evidence is only circumstantial. From cytogenetic studies,
several genetic abnormalities have been identified as characteristic of tumor cells (34-36). These chromosomal aberrations include increases or reductions in chromosome numbers, translocations, deletions, inversions, isochromosomes,
ring chromosomes, double minutes, and homogeneously
stained regions. The identification
of potential
cellular
oncogenes, and the subsequent mapping of these cellular
genes to specific chromosome locations, have produced evidence that many of the chromosomal aberrations may effect
these cellular oncogenes, resulting in a disruption of their
normal expression. It is intriguing to speculate that these
chromosomal abnormalities do contribute to the neoplastic
state, and that the molecular consequences of these chromesomal events are to activate the oncogenic properties of
cellular proto-oncogenes.
One mechanism of oncogene activation involves the quantitative overexpression of the oncogene product (37, 38). In
particular, certain cellular proto-oncogenes are amplified in
tumor cells (Table 3). Associated with gene amplification is
a corresponding overexpression of the oncogene product. The
oncogene amplification observed has ranged from severalfold to several hundred-fold. In some tumors, the amplified
oncogene is located in double-minute
chromosomes and
homogeneously
staining regions, chromosome abnormalities characteristic of gene amplification (39-42).
Several studies have reported the consistent amplification
of a particular oncogene in certain neoplasms. For example,
Table 3. Oncogene Amplification in Human Tumors
Oncogene
N-myc
L-myc
c-myc
myb
ab!
erb-B
erb-B2
Ha-ras
Ki-ras
N-ras
Tumor
Neuroblastoma,retinoblastoma,small cell lung
carcinoma,astrocytoma
Small cell lungcarcinoma
Small cell lungcarcinoma,chronicgranulocytic
leukemia,acute myelocyticleukemia,colon
carcinoma,plasmacell leukemia,breast
carcinoma,gastricadenocarcinoma
Acute myelocyticleukemia,coloncarcinoma
Chronicmyelocyticleukemia
Epidermoidcarcinoma,glioblastoma,squamouscell
carcinoma
Salivaryadenocarcinoma,gastricadenocarcinoma,
mammarycarcinoma
Bladdercarcinoma
Pancreaticcarcinoma,coloncarcinoma,lung
carcinoma,ovariancarcinoma,epidermoid
carcinomaof the lung
Mammary carcinoma
N-myc amplification
has been associated with a number of
human neuroblastoma cell lines and primary isolates (4143), and the degree of N-myc amplification may have a key
role in determining the aggressiveness
of neuroblastomas
(43). N-myc, c-myc, and L-myc amplifications appear to be
frequent occurrences in small-cell lung carcinomas (44-46).
Aside from amplification
of myc family oncogenes, the
majority of other oncogene activations observed represent
limited occurrences, present only in established cell lines or
in a few tumor samples tested. Consequently, the significance of these amplifications to tumor formation has not
been established.
The primary consequence of gene amplification is overexpression of the oncogene product. However, gene amplification may not be a purely quantitative mechanism; in some
cases of oncogene amplification, the amplified gene has also
been found to be structurally
altered (47, 48). Finally,
oncogene overexpression
may also occur by mechanisms
other than gene amplification, such as by mutations in the
regulatory
sequences of the oncogene (49), or by chromosome duplication (45).
Another mechanism of oncogene activation has been
identified from cytogenetic studies of tumor cells. Since
1970, and in association with recent developments in chromosome-banding
techniques, several specific chromosome
rearrangements
have been associated with particular subtypes of human leukemias and lymphomas (34, 35). From
these studies, a remarkable concordance between the chromosome location of certain human cellular oncogenes and
the breakpoints
involved in chromosome translocations in
various forms of cancer is becoming apparent. The two bestdocumented cases at the molecular level identi1 a regulatory activation of c-myc in Burkitt’s lymphoma and structural alteration of c-abl in chronic myelocytic leukemias, both
as a consequence of the chromosome rearrangement.
Burkitt’s lymphoma is a neoplastic condition involving B
cells and predominantly affecting children. In 95% of the
cases, a reciprocal translocation of the distal end of the long
arm of chromosome 8 with either chromosomes 2, 14, or 22
is observed (50). Of these, 85% represent a translocation
between chromosomes 8 and 14. The net result is the
translocation of the c-myc locus on chromosome 8 to the
heavy chain locus on chromosome 14 (51, 52). Molecular
analysis of numerous Burkitt’s t(8;14) translocations demonstrates that there does not appear to be one common way
in which translocations effect the expression and function of
the c-myc gene. The general consensus is that the translocated c-myc is now altered in its regulation, while leaving its
region for protein coding intact (49).
A second well-characterized
involvement
of a cellular
proto-oncogene in a specific chromosome translocation is
observed in chronic myelocytic leukemia. This pluripotent
stem-cell disease is characterized
by the presence of the
Philadelphia (Phi) chromosome in the leukemic cells of 96%
of all patients (53). The abnormal small Phi chromosome is
the result of a reciprocal translocation involving chromosomes 9 and 22, having as its main consequence the shifting
of the c-abl gene from chromosome 9 to 22. Molecular
analysis of the breakpoints in this translocated
region
reveals the involvement of the c-abl locus from chromosome
9 and a small DNA segment on chromosome 22, designated
as the breakpoint cluster region (bcr), resulting in the
formation of a fused bcr/abl gene (54, 55). The resulting
chimeric sequence encodes for an abnormal hybrid protein
that possesses a tyrosine kinase activity not present in the
normal c-abl encoded protein, but similar to that of the
protein product of the transforming
viral abi gene (56).
Thus, in contrast to the altered regulation of myc in Burkitt’s lymphoma, the translocated
c-abl gene results in the
expression of an aberrant abi protein.
A third body of evidence in support of a role for cellular
genes in human carcinogenesis
comes from transfection
studies, which have identified a growing number of cellular
sequences that are activated in tumor cells (Table 4). The
identification of cellular genes whose activities and structures are abnormal in tumor cells provides strong implications for their involvement in tumor developments. Molecular analysis of these activated sequences has identified
structural
alterations
that distinguish
them from their
normal counterparts and that are responsible for the activation of their oncogenic properties. The structural alteration
may be subtle, involving the change of only a single amino
acid (e.g., ma and neu) (57-60), or may involve significant
loss of amino acid sequences via amino or carboxyl terminal
rearrangements
(e.g., met and m/4) (61, 62).
The best characterized
example of oncogene activation by
structural mutations is represented by the activated cellular
rca genes. Nucleotide sequence comparisons between normal and activated ma genes have identified the mechanism
Table 4. Human Tumors with Activated Cellular ras
Genes
ActIvated ras
gene
Cell lines
Ha-ras
Ki-ras
N-ras
Tumor isolates
Ha-ras
Ki-ras
N-ras
Tumor(no. observed)
Bladdercarcinoma,lungcarcinoma,melanoma
Bladdercarcinoma,coloncarcinoma(3), gall
bladdercarcinoma,lungcarcinoma(7),
pancreaticcarcinoma,acute lymphocytic
leukemia
Lungcarcinoma,fibrosarcoma,
rhabdomyosarcoma, acute lymphocytic
leukemia(5), Burkitt’s lymphoma, chronic
myelocytic leukemia, acute myelocytic
leukemia(2), melanoma(3), neuroblastoma,
teratocarcinoma
Bladdercarcinoma,renal pelviccarcinoma
Coloncarcinoma,lungcarcinoma(5), ovarian
carcinoma,pancreaticcarcinoma,
rhabdomyosarcoma,semanoma
Gastriccarcinoma,acute myelocyticleukemia
(6)
CLINICALCHEMISTRY,Vol. 33, No. 5, 1987 643
of activation to be a consequence of nucleotide point niutations in the ma coding region, resulting in single amino acid
substitutions (57-59). Additionally, with the use of synthetic DNA oligonucleotide probes (63), ins gene activation has
now been identified to involve two principal hot spots for
activation. Nucleotide substitutions at codons i2, i3, or 61
have been identified in activated ma genes to result in
single amino acid substitutions that are sufficient for the
activation of ins oncogenic activity (63-68a). In vitro mutagenesis studies have further determined that i8 different
amino acid substitutions at position 12 (69) and 15 different
amino acid substitutions at position 61 (70) will activate Hma transforming activity. Thus, the introduction of structural mutations around positions 12 or 61 of the different ma
proteins result in ins activation, either by introducing a
defect in the normal ins function or, alternatively,
by
activating a novel activity not present in the normal proteins. Finally, experimental overexpression of the normal
human Ha-ma gene will also activate ma-transforming
activity (71), suggesting that the oncogemc properties of the
rca proteins may be activated by either structural or regulatory alterations.
Role of Suppressor
Oncogenesis
Genes (Anti-Oncogenes) in
A second type of genetic loci believed to be important in
the pathogenesis of cancer are suppressor genes, or antioncogenes (72, 73). Unlike the mechanism of oncogene
action, lesions at these genetic loci appear to behave in a
recessive manner (76), requiring
the alteration of both
alleles of the gene. Additionally, whereas oncogene involvement in carcinogenesis
occurs via activating mutations,
genetic lesions that inactivate suppressor gene activity are
believed to contribute to the malignant process.
The physical evidence for the existence of suppressor
genes comes primarily from the study of hereditary cancers,
where offspring of affected persons inherit a predisposition
to one or a few specific cancers, as an autosomal dominant
trait. In particular, much of our recent information comes
from the study of two embryonic tumors, primarily retinoblastomas (75, 76) and more recently Wilms’ tumors (7780). In both instances, the demonstration of their recessiveness has depended upon two principal observations. First,
cytogenetic studies have identified the existence of constitutional deletions in a percentage of patients, thereby permitting the chromosomal localization of the genes. Second, the
use of linked polymorphic genetic markers (RFLPs) has
identified the loss of heterozygosity of the affected chromosome in the tumor.
The general model for suppressor gene involvement in
carcinogenesis is based on the study of retinoblastomas (75,
76), a childhood tumor of embryonic neural retina that
occurs in heritable and nonheritable forms. In heritable
cases, a germ-line mutation at the retinoblastoma locus (Rb1) on chromosome 13 has been proposed. This may occur via
a chromosome deletion or some other submicroscopic lesion.
However, the presence of this inherited mutation is not
sufficient for tumor formation; that is, the effect of the
mutation is recessive. Rather, a second mutational (somatic)
event is required, which has the net result of unmasking the
initial Rb-i mutation. Similarly, in nonheritable forms, two
somatic events are hypothesized to occur at each Rb-i locus.
Several genetic events can be envisioned that will result
in the specific loss of the remaining normal Rb-i locus: (a)
chromosome loss, involving the loss of the whole chrome644
CLINICAL CHEMISTRY, Vol. 33, No. 5, 1987
some 13 carrying the nonmutated
Rb-i locus without chromosome duplication (homozygosity), or with reduplication of
the remaining
chromosome; (b) mitotic recombination, so
that the part of the chromosome containing the mutation
becomes homozygous; (c) chromosome translocation, leading
to deletion or inactivation of the locus; and (d) submicroscopic mutations, such as insertions, inversions, or point mutations. Because the specific location of the Rb-i locus is not
known, the analysis of the genetic mechanisms involved has
been limited to the investigation
of gross chromosomal
changes. The use of RFLPs for various regions of chromosome 13 has identified examples of mechanisms a-c in
retinoblastoma
patients. With the development of more
refined genetic probes, and the isolation of the Rb-i locus
(81), a more thorough understanding
of the genetic events
involving this gene in retinoblastomas
will become evident.
Finally, from our present knowledge of the mechanism of
action of suppressor genes, the number of loci at which
recessive mutations can predispose individuals
to cancer
appears to be limited, with each such locus having a broad,
but specific, spectrum of tissues in which it is active. For
example, the Rb-i locus is also believed to predispose
survivors of retinoblastomas
to the development of second
primary tumors, most commonly osteosarcomas
(82). Similarly, the Wilma’ tumor locus appears to be associated with
the pathogenesis of two additional embryonic tumors, hepatoblastoma and rhabdomyosarcoma (83). Thus, in contrast
to the apparent broad tissue involvement of certain cellular
oncogenes (e.g., ma), suppressor genes appear to display a
considerable tissue specificity.
Because carcinogenesis is a multi-step process, no doubt
additional genetic events, and additional genetic targets for
their action, remain to be elucidated. However, the implication of specific cellular genes in the process, the identification of the specific genetic lesions that result in their
activation (or inactivation), and the determination of the
contribution of these genetic events to human carcinogenesis should provide a better understanding
of the crucial
molecular events leading to human malignancy.
As the
specific role of each cellular gene becomes known, the
advent of genetic probes to identify genetic abberrations
in
these genetic loci will become important for their potential
diagnostic and therapeutic applications in cancer.
References
1. Bishop JM. Cellular oncogenes and retroviruses. Ann Rev Biochem 1983;52:301-54.
2. Duesberg PH. Retroviral transforming genes in normal cells?
Nature (London) 1983;304:219-26.
3. Cooper GM. Cellular transforming genes. Science 1982;217:8016.
4. Weinberg RA. The action of oncogenea in the cytoplasma and
nucleus. Science 1985230:770-6.
5. Powers S, Kataoka T, Fasano 0, et al. Genes in S. cerevisiae
encoding proteins with domains homologous to the mammalian ins
proteins. Cell 1984;36:607-12.
6. Shilo BZ, Weinberg WA. DNA sequences homologous to vertebrate oncogenes are conserved in Drosophila melanogaster. Proc
Natl Aced Sci USA 1981;78:6789-92.
7. Reymond CD, Gomer RH, Mehdy MC, Firtel RA. Developmental
regulation of a Dictyostelium gene encoding a protein homologous to
a mammalian ms protein. Cell 1984;39:141-9.
8. Hill M, Hillova J. Virus recovery in chicken cells tested with
Ross sarcoma cell DNA. Nature (London) 1972;237:35-9.
9. Balmain A. Transforming ins oncogenes and multistage carcinogenesis. Br J Cancer 1985;51:1-7.
10. Shimizu K, Nakatsu
Y, Sekiguchi
M, et al. Molecular cloning of
an activated human oncogene, homologous to v-mi, from primary
stomach cancer. Proc Natl Aced Sci USA 1985;82:5641-5.
11. Birchmeier C, Birnbaum D, Waitches G, Fasano 0, Wigler M.
Characterization
of an activated human ins gene. Mol Cell Biol
1986;6:3109-16.
12. Fukui M, Yamamoto
T, Kawai S, Maruo K, Toyoshima K.
Detection of a mi-related and two other transforming
DNA sequences in human tumors maintained in nude mice. Proc NatI Aced
Sci USA 1985;82:5954-8.
13. Diamond A, Cooper GM, Ritz J, Lane MA. Identification and
molecular cloning of the human B-Iym transforming gene activated
in Burkitt’s lymphomas. Nature (London) 1983;305:112-6.
14. Padua BA, Barrass N, Currie GA. A novel transforming
gene
in a human malignant melanoma cell line. Nature (London)
1984;311:671-3.
15. Eva A, Aaronson ST. Isolation of a new human oncogene from a
diffuse B-cell lymphoma. Nature (London) 1985;316:273-5.
16. Martin-Zanca D, Hughes SH, Barbacid M. A human oncogene
formed by the fusion of truncated tropomyosin and protein tyrosine
kinase sequences. Nature (London) 1986;319:743-8.
17. Takahashi M, RItZJ, Cooper GM. Activation of a novel human
transforming gene, met, by DNA rearrangement.
Cell 1985;42:5818.
18. Young D, Waitches G, Birchmeier C, Fasano 0, Wigler M.
Isolation and characterization of a new cellular oncogene encoding a
protein with multiple potential transmembrane
domains. Cell
1986;45:711-9.
19 Schechter AL, Stern DF, Vaidysnathan
L, et al. The neu
oncogene: an erb-B-related
gene encoding a 185 000 M tumor
antigen. Nature (London) 1984;312:513-6.
20. Cooper CS, Park M, Blair DG, et al. Molecular cloning of a new
transforming gene from a chemically transformed human cell line.
Nature (London) 1984;311:29-33.
21. Der CJ, Krontiris TO, Cooper GM. Transforming
genes of
human bladder and lung carcinoma cell lines are homologous to the
ins genes of Harvey and Kirsten sarcoma viruses. Proc Nati Aced
Sci USA 1982;79:3637-40.
22. Parada LF, Tabin CJ, Shih C, Weinberg BA. Human EJ
bladder carcinoma oncogene is homologue of Harvey sarcoma virus
ins gene. Nature (London) 1982;297:474-8.
23. Santos E, Tronick SR, Aaronson SA, Pulciana 5, Barbacid M.
T24 human bladder carcinoma oncogene is an activated form of the
normal human homologue of Balb- and Harvey-MSV transforming
genes. Nature (London) 1982;298:343-7.
24. Shimizu K, Goldfarb M, Suard Y, et al. Three human transforming genes are related to the viral ins oncogenes. Proc Natl Acad
Sci USA 1983;80:2112-6.
25. Shimizu K, Goldfarb M, Perucho M, Wigler M. Isolation and
preliminary characterization
of the transforming gene of a human
neuroblastoma cell line. Proc Nati Aced Sci USA 1983;80:383-7.
25a. Hall A, Marshall CJ, Spurr NK, Weiss BA. Identification of
transforming
gene in two human sarcoma cell lines as a new
member of the ins gene family located on chromosome 1. Nature
(London) 1983;303:396-400.
26. Land H, Parada LF, Weinberg BA. Cellular oncogenes and
multistep carcinogenesis. Science 1983;222:771.-8.
27. Cooper GM, Lane MA. Cellular transforming
genes and oncogenesis. Biochim Biophys Acts 1984;738:9-20.
28. Santos E, Martun-Zanca D, Reddy EP, Pierotti MA, Della-Ports
G, Barbacid M. Malignant activation of a K-ms oncogene in lung
carcinoma but not in normal tissue of the same patient. Science
1984223:661-4.
29. Feig LA, Bast RC Jr, Knapp RC, Cooper GM. Somatic activation of masK gene in a human ovarian carcinoma. Science
1984;223:698-Oi.
30. O’Hara BM, Oskarsson M, Tainsky MA, Blair DG. Mechanism
of activation of human ins genes cloned from a gastric adenocarcinoma and a pancreatic
carcinoma
cell line. Cancer Res
1986;46:4695-700.
31. Balmain A, Pragnell lB. Mouse skin carcinomas induced in
vivo by chemical
carcinogens
have
a transforming
Harvey-ms
oncogene. Nature (London) i983;303:72-4.
32. Sukumar S, Notario V, Martin-Zance D, Barbacid M. Induction
of mammary carcinomas in rats by nitroso-methylurea
involves
malignant activation of H-ms-i locus by single point mutations.
Nature (London) 1983;306:658-62.
33. Guerrero I, Villasante A, Corces V, Pellicer A. Activation of a cK-ms oncogene by somatic mutation in mouse lymphomas induced
by gamma radiation. Science i984225:1159-62.
34. Yunis JJ. The chromosomal basis of human neoplasia. Science
1983;221:227-36.
35. Rowley JD. Human oncogene locations and chromosome abberrations. Nature (London) i983;301:290-1.
36. Bishop IM. Cancer genes come of age. Cell i983;32:10i8-20.
37. Marx JL. Oncogenes amplified in cancer cells. Science
i984;223:40-i.
38. Alitalo K. Amplification of cellular oncogenes in cancer cells.
Med Biol 1984;62:304-17.
39. Alitalo K, Schwab M, Lin CC, Varmus HE, Bishop JM.
Homogeneously staining chromoeomal regions contain amplified
copies of an abundantly expressed cellular oncogene (c-myc) in
malignant
neuroendocrine
cells from a human colon carcinoma.
Proc Natl Aced Sci USA i983;80:i707-i1.
40. Alitala K, Winqviat R, Liii CC, De La Chapelle A, Schwab M.
Aberrant expression of an amplified c-myb oncogene in two cell
lines from a colon carcinoma.
Proc Natl Aced Sci USA
i984;81:4534-8.
41. Schwab M, Alitalo K, Klempnauer K-H, et al. Amplified DNA
with limited homology to myc cellular oncogene is shared by human
neuroblastoma cell lines and a neuroblastoma tumor. Nature
(London) i983;305:245-8.
42. Kohl NE, Kanda N, Schreck BR, et al. Transposition and
amplification of oncogene-related
sequences in human neuroblastomas. Cell 1983;35:359-67.
43. Seeger RC, Brodeur GM, Sather H, et al. Association of
multiple copies of the N-myc oncogene with rapid progression of
neuroblastomas.
N Engi J Med 1985;313:iiil-6.
44. Little CD, Nau MM, Carney DN, Gazdar AF, Minna JD.
Amplification and expression of the c-myc oncogene in human lung
cancer cell lines. Nature (London) 1983;306:194-6.
45. Wong AJ, Ruppert JM, Eggleston J, Hamilton SR. Baylin SB,
Vogelstein B. Gene amplification of c-myc and N-myc in small cell
carcinoma of the lung. Science i986233:46i-4.
46. Nau MM, Burke JB, Battey J, et a!. L-myc, a new myc-related
gene amplified and expressed in human small cell lung cancer.
Nature (London) i985;3i8:69-75.
47. Ullrich A, Couasens L, Hayffick JS, et al. Human epidermal
growth factor receptor CDNA sequence and aberrant expression of
the amplified gene in A431 epidermoid carcinoma cells. Nature
(London) 1984;309:418-25.
48. Yamada H, Sakamoto H, Taira M, et a!. Amplifications of both
c-Ki-ms with a point mutation and c-myc in a primary pancreatic
cancer and its metastatic tumors in lymph nodes. Jpn J Cancer Res
1986;77:370-5.
49. Leder P, Battey J, L.enoir G, et a!. Translocations
among
antibody genes in human cancer. Science 1983;222:765-7i.
50. Croce CM, Nowell PC. Molecular basis of human B cell
neoplasia. Blood 1985;65:1-7.
51. Dalla-Favera B, Bregni M, Erikson J, Patterson D, Gallo BC,
Croce CM. Human c-myc oncogene is located on the region of
chromosome 8 that is translocated in Burkitt lymphoma cells. Proc
Natl Aced Sci USA 1982;79:7824-7.
52. Taub R, Kirsch I, Morton C, et a!. Translocation of the c-myc
gene into the immunoglobulin heavy chain locus in human Burkitt
lymphoma and murine plasmacytoma
cells. Proc Natl Aced Sci
USA 1982;79:7837-41.
53. Rowley JD. Biological implications of consistent chromosome
rearrangements
in leukemia
and lymphoma.
Cancer Res
1984;44:3159-68.
54. Groffen J, Stephenson ,JR, Heisterkamp N, de Klein A, Bartrsm
CR, Grosveld G. Philadelphia chromosomal breakpoints are clusCLINICAL CHEMISTRY, Vol. 33, No. 5, 1987 645
tered within
a limited
region, bcr, on chromosome 22. Cell
1984;36:93-9.
55. Canaani
Januszewics
E, Gale RP, Steiner-Salts D, Berebbi A, Aghai E,
E. Altered transcription of an oncogene in chronic
myeloid leukaemia.
Lancet
i984;i:593-5.
56. Konopka JB, Watanabe SM, Witte ON. An alteration of the
human c-abl protein in K562 leukemia cells unmasks associated
tyrosine kinase activity. Cell 1984;37:1035-42.
57. Tabin CJ, Bradley SM, Bargmann CI, et a!. Mechanism of
activation of a human oncogene. Nature (London) 1982;300:143-9.
58. Reddy EP, Reynolds BK, Santos E, Barbacid M. A point
mutation is responsible for the acquisition of transforming properties by the T24 human bladder carcinoma oncogene. Nature (London) 1982;300:i49-52.
59. Taparowsky E, Suard Y, Fasano 0, Shimizu K, Goldfarb M,
Wigler M. Activation of T24 bladder carcinoma transforming gene
is linked to a single amino acid change. Nature (London)
1982;300:762-5.
60. Bargmann CI, Hung MC, Weinberg BA. Multiple independent
activations of the neu oncogene by a point mutation altering the
transmembrane
domain of p185. Cell i986;45:649-57.
61. Park M, Dean M, Cooper CS, eta!. Mechanism of met oncogene
activation. Cell i986;45:895-04.
62. Bonner TI, Kerby SB, Sutrave P, Gunnell MA, Mark G, Rapp
UR Structure and biological activity of human homologs of the raft
mU oncogene. Mo! Cell Biol 1985;5:i400-7.
63. Boa JL, Toksoz D, Marshall CJ, eta!. Amino-acid substitutions
at codon 13 of the N-ms oncogene in human acute myeloid
leukaemia. Nature (London) 1985;315:726-30.
64. Capon N, Seeburg PH, McGrath JP, eta!. Activation of Ki-mus
2 gene in human colon and lung carcinomas by two different point
mutations. Nature (London) i983;304:507-13.
65. Shimizu K, Birnbaum D, Ruley MA, et a!. Structure of the Niras gene of the human lung carcinoma cell line Ca!u-i. Nature
(London) 1983;304:497-500.
66. Yamamoto F, Perucho
M. Activation
of a human c-K-ms
oncogene. Nuci Acids Res 1984;12:8873-85.
67. Tainsky MA, Cooper CS, Giovanella BC, Vande Woude GF. An
activated msN gene: detected in late but not early passage human
PAl teratocarcinoma
cells. Science 1984;225:643-5.
68. Taparowsky E, Shimizu K, Goldfarb M, Wigler M. Structure
and activation of the human N-ms gene. Cell 1983;34:581-6.
68& Yuasa Y, Srivastava
SK, Dunn CY, Rhim JS, Reddy EP,
Aaronson SA. Acquisition of transforming properties by alternative
point mutations within c-bas/has human proto-oncogene. Nature
(London) 1983;303:775-9.
646 CLINICALCHEMISTRY,Vol. 33, No. 5, 1987
69. Seeburg PH, Colby WW, Hayflick JS, Capon N, Goeddel DV,
Levunson AD. Biological properties of human c-Ha-msi genes
mutated at codon 12. Nature (London) 1984;312:71-5.
70. Der (II, Finkel T, Cooper GM. Biological and biochemical
properties of human rasH genes mutated at codon 61. Cell
1986;44:167-6.
71. Chang EH, Furth ME, Scolmck EM, Lowy DR. Tumorigenic
transformation of msimmahan cells induced by a normal human
gene homologous to the oncogene of Harvey murine sarcoma virus.
Nature (London) 1982297:479-83.
72. Sager R. Genetic suppression of tumor formation: a new frontier in cancer research. Cancer Res 1986;46:1573-80.
73. Stanbridge EJ, Der CJ, Doersen (11, eta!. Human cell hybrids:
analysis of transformation
and tumorigenicity.
Science
1982215:252-9.
74. Knudson AG Jr. Hereditary cancer, oncogenes and anti-oncegenes. Cancer Res 1985;45:1437-43.
75. Cavenee WK, Dryja TP, Phillips BA, et a!. Expression of
recessive alleles by chromosoma! mechanisms in retunoblastoma.
Nature (London) 1983;305:779-84.
76. Benedict WF, Murphree AL, Banerjee A, Spina CA, Sparkes
MC, Sparkes ES. Patient with 13 chromosome deletion: evidence
that the retunoblastoma gene is a recessive cancer gene. Science
1983;219:973-5.
77. Koufos A, Handen MF, Lanipkin BC, eta!. Loss of alleles at loci
on human chromosome 11 during genesis of Wilma’ tumour. Nature
(London) 1984;309:i70-2.
78. Orkin SH, Goldman DS, Sallan SE. Development of homozygosity for chromosome lip markers in Wilma’ tumour. Nature
(London) 1984;309:i72-3.
79. Reeve AE, Housiaux PJ, Gardner RJM, Chewings WE, Grindley EM, Millow U. Loss of a Harvey ms allele in sporadic Wilma’
tumour. Nature (London) 1984;309:174-6.
80. Fearon ER, Vogelstein B, Feunberg AP. Somatic deletion and
duplication of genes on chromosome ii in Wilma’ tumours. Nature
(London) 1984;309:176-8.
81. Friend SH, Bernarda R, Rogelj S, eta!. A human DNA segment
with properties of the gene that predispoees to retinoblastoma and
osteosarcoma. Nature (London) 1986;323:643-6.
82. Hansen MF, Koufos A, Gallie BL, et a!. Oateosarcoma and
retinoblastoma:
a shared chromosomal mechanism revealing recessive predisposition. Proc Natl Acad Sci USA 1985;82:6216-20.
83. Koufos A, Hansen MF, Copeland NG, Jenkins NA, Lampkun
BC, Cavenee WK. Loss of heterozygosity
in three embryonal
tumours suggests a common pathogenetic mechanism.
Nature
(London) 1985;316:330-4.