Download Loss of Heterozygosity at 6q Is Frequent and Concurrent with 3p

Journal of Neuropathology and Experimental Neurology
Copyright q 2004 by the American Association of Neuropathologists
Vol. 63, No. 10
October, 2004
pp. 1072 1079
Loss of Heterozygosity at 6q Is Frequent and Concurrent with 3p Loss in Sporadic and Familial
Capillary Hemangioblastomas
SEBSEBE LEMETA, MD, LEA PYLKKÄNEN, PHD, MARKKU SAINIO, MD, PHD, MIKA NIEMELÄ, MD, PHD,
SIRKKU SAARIKOSKI, PHD, KIRSTI HUSGAFVEL-PURSIAINEN, PHD, AND TOM BÖHLING, MD, PHD
Abstract. Capillary hemangioblastoma is a benign tumor, occurring sporadically or as a manifestation of von Hippel-Lindau
(VHL) disease. Inactivation of the VHL gene at 3p25–26 has been demonstrated in all VHL-associated hemangioblastomas.
However, the VHL gene has been found to be inactivated in only 20% to 50% of sporadic tumors. So far, no other gene has
been reported to be involved in the development of hemangioblastomas. DNA losses at 6q are frequent alterations in hemangioblastomas, as shown by comparative genomic hybridization. We therefore analyzed 15 hemangioblastomas for loss of
heterozygosity (LOH) on chromosome 3p and 6q to reveal the frequency of allelic losses and to determine minimal deleted
areas. We detected LOH at 6q for one or more markers in 11 (73%) out of 15 cases (in 9 of 11 sporadic and in 2 of 4 VHLassociated tumors). The analyses revealed a minimal 3-megabase (Mb) deleted region at 6q23–24, where 9 of 11 (82%)
informative cases showed LOH. LOH at 3p was seen in 14 out of 15 tumors. LOH occurred concurrently at 6q and 3p in
67% of cases. Our data strongly suggests that a tumor suppressor gene located at 6q23–24 is involved in tumorigenesis of
hemangioblastomas, in addition to the VHL gene.
Key Words:
6q loss; Chromosomal aberration; Hemangioblastoma; Loss of heterozygosity (LOH); Tumor suppressor gene.
INTRODUCTION
Capillary hemangioblastomas are solid or cystic benign tumors that are highly vascular, grow slowly, and
account for less than 2% of all central nervous system
tumors (1). They can occur in any part of the CNS, but
the sites of predilection are the posterior fossa and the
spinal cord. Regardless of their location, hemangioblastomas have the same histologic characteristics (2, 3).
Hemangioblastomas occur either as a manifestation of
von Hippel-Lindau (VHL) disease or as solitary sporadic
lesions. VHL is a dominantly inherited disorder characterized by tumors or tumor-like lesions developing in several organs, including retinal hemangioblastomas, clear
cell renal carcinomas (RCC), pheochromocytomas, pancreatic islet cell tumors, as well as renal, pancreatic and
epididymal cysts; hemangioblastomas of the central nervous system are nevertheless the most common manifestation (4, 5). In VHL patients, hemangioblastomas are
frequently multiple and occur at an earlier age as compared to sporadic tumors. The proportion of VHL-associated tumors is 10% to 40% of all hemangioblastomas
From Department of Pathology, University of Helsinki, and Helsinki
University Central Hospital (SL, TB), Helsinki, Finland; Departments
of Industrial Hygiene and Toxicology (S L, LP, SS, KH-P) and Occupational Medicine (MS), Finnish Institute of Occupational Health; and
Department of Neurosurgery (MN), Helsinki University Central Hospital, Helsinki, Finland.
Correspondence to: Tom Böhling, MD, PhD, Department of Pathology, Haartman Institute, University of Helsinki, P.O. Box 21, (Haartmaninkatu 3), FIN-00014, Helsinki, Finland. E-mail tom.bohling@
helsinki.fi
Supported by grants from the Finnish Cancer Foundation, Finska
Läkaresällskapet, K.A. Johansson Foundation and Helsinki University
Central Hospital (EVO).
(6). Germ-line mutations of the VHL tumor suppressor
gene, located at 3p25–26 (7), have been reported in all
VHL families (8). A two-hit inactivation of the VHL gene
has been shown in both VHL-associated and sporadic
hemangioblastomas (9). However, studies on sporadic
hemangioblastomas, including somatic mutation analyses, LOH, and hypermethylation studies have revealed
loss or inactivation of the VHL gene area only in approximately 20% to 50% of the cases (10–14). Thus, the
genetic mechanisms underlying the tumorigenesis of sporadic hemangioblastomas are still unclear.
We and others have recently shown by comparative
genomic hybridization (CGH) DNA losses on chromosomal arm 6q, in addition to those on 3p (15, 16). Losses
of 6q were seen in 23% and 50% of the tumors, and they
were the most or second most frequent DNA copy number changes after 3p loss (15, 16).
With this background, we investigated the frequency
of LOH at 6q in both sporadic and VHL-associated hemangioblastomas, in order to determine allele losses not
observable by CGH. We sought to reveal the minimal
deleted area to uncover the location of putative tumor
suppressor genes important in hemangioblastoma tumorigenesis. In addition to prevalent 3p loss, we found LOH
of 6q in 73% of the cases. To our knowledge, this is the
first report documenting LOH in hemangioblastomas on
the long arm of 6, with the minimal deleted region discovered at 6q23–24.
MATERIALS AND METHODS
Paraffin-embedded tumor tissue from 15 surgically removed
hemangioblastomas, fixed in 4% phosphate-buffered formaldehyde was collected from the files of the Department of Pathology, University of Helsinki. The set included 11 sporadic
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LOH AT 6q IN CAPILLARY HEMANGIOBLASTOMAS
TABLE 1
Clinical Characteristics of Cases with Capillary Hemangioblastomas with a Summary of CGH and LOH Findings
Sample
No.
Sex
Location
Age at
surgery
VHL-associateda
T2
T5
T14
T15
M
M
M
F
Medulla
Medulla
Cerebellum
Medulla
32
21
34
48
Sporadic
T1
T3
T4
T6
T7
T8
T9
T10
T11
T12
T13
M
M
M
M
M
M
F
F
F
M
M
Cerebellum
Cerebellum
Cerebellum
Cerebellum
Cerebellum
Cerebellum
Cerebellum
Cerebellum
Cerebellum
Cerebellum
Cerebellum
39
32
37
79
46
55
69
27
48
45
25
Loss in
CGHb
LOH
at 6qc
LOH
at 3pc
—
—
n.a.
n.a.
1
2
2
1
2
1
1
1
—
3p, 6q
n.a.
3p, 6q
6q
6q
—
—
n.a.
n.a.
n.a.
2
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
See Materials and Methods.
Reference 15.
c
This study.
n.a., Not analyzed.
1, LOH detected.
2, No LOH or DNA loss detected.
a
b
and 4 VHL-associated (VHL characterization described elsewhere [6]). The clinical characteristics of the patients are presented in Table 1. Nine of the 15 tumors were part of both
CGH and LOH studies.
DNA was extracted from histologically well-characterized
paraffin sections of hemangioblastomas, from which adjacent
normal tissues were carefully removed, and from corresponding peripheral blood samples by standard methods using proteinase-K digestion and phenol/chloroform purification followed by ethanol precipitation. Tumor and non-tumor DNA
was amplified by the polymerase chain reaction (PCR), and
LOH analysis was performed with 22 microsatellite markers
(Research Genetics, Inc, Huntsville, AL) covering chromosome 6q and 16 spanning 3p. The markers (Figs. 1, 2) were
selected to ensure a comprehensive representation of 6q and
3p. The names and the localization of the markers are based
on the unified database (UDB) (http://bioinformatics.
weizmann.ac.il/udb). PCR was carried out in the following
conditions: 13 PCR buffer (10 mM Tris-HCl, 1.5 mM MgCl2,
50 mM KCl, 0.1% Triton X-100); 200 mM dGTP, dATP and
dTTP; 2 mM dCTP; 0.7 mCi of [33 P] dCTP (3,000 Ci/mmol);
10 ng of each primer; 100 ng of genomic DNA template; and
0.5 units of Dynazyme II polymerase (Finnzymes, Espoo, Finland) in a volume of 10 ml. PCR amplification started with 5
min at 958C, then 35 cycles for 1 min at 958C, 1 min at 52–
558C, 1 min at 728C, followed by elongation for 8 min at 728C.
The amplified samples were cooled down quickly and stored
at 48C. Heat-denatured PCR products were subjected to electrophoresis in 6% polyacrylamide gel containing 7.7 M urea.
After electrophoresis, the gels were dried and exposed by autoradiography to X-ray film.
All PCR amplifications with unclear results were repeated.
LOH was scored when an allelic band was absent or clearly
reduced in density compared to the corresponding band in normal DNA in repeated experiments. All of the 15 cases were
informative for more than 1 marker studied (a marker was
considered non-informative when the normal tissue of the patient was homozygous with respect to this marker).
RESULTS
Altogether, 15 cases of hemangioblastomas were investigated for LOH at 6q and 3p regions with a comprehensive set of microsatellite markers. LOH was observed
with at least 1 marker in all 15 cases (Figs. 1, 2; Table
1). The detection of allele loss for both 6q and 3p in 2
cases is illustrated in Figure 3.
Allelic losses of 6q were detected in 11 (73%) of the
15 tumors (Fig. 1). Nine of these 11 cases were sporadic
tumors, and 2 were VHL-associated. In the sporadic tumors, the prevalence of 6q LOH was thus 83%. In the
VHL-associated tumors, 6q LOH was seen in 2 (50%)
out of the 4 tumors included in the study. Four tumors
(T3, T6, T7, and T8) showed DNA loss on the long arm
of chromosome 6 in the previous CGH study (15) and
for 3 of those, 6q LOH was also detected (Fig. 1).
The results allowed us to define a minimal deleted region between markers D6S250 and D6S1705. Nine
(82%) of the informative cases showed LOH with at least
one of the markers (D6S250, D6S1703, or D6S1705).
These markers span a 3-Mb region on 6q23–24 (Fig. 1).
J Neuropathol Exp Neurol, Vol 63, October, 2004
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LEMETA ET AL
LOH AT 6q IN CAPILLARY HEMANGIOBLASTOMAS
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Fig. 2. Loss of heterozygosity (LOH) on the short arm of chromosome 3 in capillary hemangioblastoma. The delineated
schematic chromosome arm indicates the approximate locations of the microsatellite markers used. The horizontal bar shows the
VHL regional at 3p 25–26. Symbols used: m LOH; M No LOH; V Not informative; — No result. a The order of the markers,
their distance from the telomere of the short arm of the chromosome (pter) in megabases (Mb) and the chromosomal location
are based on the database (http://bioinformatics.weizmann.ac.il/udb). For the markers D3S1255 and D3S1481 no distance in Mb
was indicated. b Tumors 3 and 6 with CGH 3p loss.
With microsatellite markers for 3p, LOH was found in
14 (93%) of the 15 cases. The only case in which 3p
LOH could not be detected was an VHL-associated tumor
in which LOH on 6q was demonstrated with several
markers. Allelic losses on 3p were detected in several
different regions (Fig. 2). LOH on 3p was also detected
in both tumors (T3 and T6) in which 3p and 6q loss had
previously been shown by CGH. In total, all 5 tumors
negative in the CGH analysis were positive in the LOH
analysis. Moreover, 2 tumors negative in the CGH analysis (T9 and T10) displayed LOH concomitantly at 6q
and 3p (Table 1).
Four tumors (2 VHL-associated and 2 sporadic)
showed LOH only at 3p and 1 VHL-associated tumor at
6q only. Concomitant LOH of 6q and 3p was detected
on 10 (67%) of the 15 cases. These 10 cases with
←
Fig. 1. Loss of heterozygosity (LOH) on the long arm of chromosome 6 in capillary hemangioblastoma. The delineated
schematic chromosome arm indicates the approximate locations of the microsatellite markers used. The minimal deleted region
discovered at 6q23–24 is indicated by the shaded areas. Symbols used: m LOH; M No LOH; V Not informative; —No result.
a
The order of the markers, their distance from the telomere of the short arm of the chromosome (pter) in megabases (Mb), and
the chromosomal location are based on the database (http://bioinformatics.weizmann.ac.il/udb). For the marker Col9A, no distance
in Mb was indicated. b Tumors 3, 6, 7, and 8 with CGH 6q loss.
J Neuropathol Exp Neurol, Vol 63, October, 2004
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LEMETA ET AL
Fig. 3. Illustration of LOH detected with the microsatellite markers D6S1698, D3S1038 in 2 tumors (T) as compared to (B)
peripheral blood or normal. The horizontal lines indicate the alleles, and the arrows show the location of the missing alleles.
LOH detected on both sites included 9 sporadic and 1
VHL-associated tumor. A summary of the results is given
in Table 2.
DISCUSSION
Various sporadic tumors are characterized by somatic
inactivation of the same genes responsible for hereditary
tumor syndromes. Hemangioblastoma is a highly vascular benign tumor of the central nervous system and one
of the major manifestations of VHL disease. The molecular basis for the development of sporadic hemangioblastoma is partially unclear. However, after discovery of
a high frequency (23%–50%) of 6q DNA loss in this
benign tumor by us and others (15, 16), we decided to
perform a detailed mapping of allelic losses on 6q using
LOH analysis. LOH for the long arm of chromosome 6
was found to be a frequent event occurring in 11 (73%)
of the 15 hemangioblastomas. The minimal common region of allelic deletion was located at 6q23–24 (D6S250D6S1705).
Losses at 6q have previously been described by CGH
and LOH in several different types of tumors, including
melanoma, ovarian carcinoma, neuroectodermal tumors,
and small cell lung cancer (17, 18, 19, 20). Loss of 6q
is also exhibited in several central nervous system tumors, including both sporadic and neurofibromatosis 2associated meningiomas (21, 22), glioblastomas (23), and
oligodendroglial tumors (24). Interestingly, in addition to
hemangioblastomas, loss of 6q has also been observed in
most other tumor types occurring in VHL, including sporadic and VHL-associated renal cell carcinomas (RRC)
J Neuropathol Exp Neurol, Vol 63, October, 2004
(25–28), pheochromocytomas (29), and endocrine pancreatic tumors (30).
Previously, 6q loss has been associated with more aggressive growth or metastatic potential in certain tumor
types (30). Hemangioblastomas are benign (2), and no
differences in clinical behavior could be associated with
LOH on 6q in our series. Interestingly, 3 of the 4 VHLassociated tumors were located in the medulla, and LOH
of 6q was detected in one of these, showing that allelic
losses at 6q is not specific to cerebellar hemangioblastomas.
Several experimental studies have provided strong evidence on the importance of 6q in the process of tumorigenicity. The transfer of a normal chromosome 6 into
breast and ovarian carcinoma cell lines suppressed their
tumorigenic potential (31, 32). Interestingly, the authors
analyzed the cell lines for the occurrence of LOH, and
they indicated the region 6q23–25 as the area for a putative tumor suppressor gene. Other studies also support
the view that this chromosome area harbors a tumor suppressor gene. Foulkes et al reported 6q allelic loss in 55%
of ovarian carcinomas and indicated that 6q24 harbors a
putative tumor suppressor gene (33). A number of other
studies on ovarian carcinomas (34–36), melanoma (37),
and prostate cancer (38) have also indicated that this region of 6q may contain a tumor suppressor gene. Acevedo et al found LOH on 6q in 48% of adenocarcinomas
of the uterine cervix by using the marker D6S250, which
is also included in the minimal deleted area discovered
in hemangioblastoma in the present study (39). Together,
these data suggest that this region may harbor a gene
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LOH AT 6q IN CAPILLARY HEMANGIOBLASTOMAS
TABLE 2
Summary of 6q and 3p LOH Results in Capillary Hemangioblastomas
6q LOH
3p LOH
Case
Present
Absent
Total
Present
Absent
Total
Sporadic
VHL-related
9
2
2
2
11
4
11
3
0
1
11
4
associated with the development or progression of a wide
variety of tumor types.
Several putative tumor suppressor genes are located in
the vicinity of 6q23–24, including the newly described
THW (human transmembrane protein) gene. THW has
been shown to be expressed in brain, kidney, liver, pancreas, adrenal glands, uterus, and prostate (40). It is located between 6q16–23, and LOH of the THW gene has
been detected in melanoma, pancreas, breast, prostate,
cervical, and colon cancer cell lines (41, 42).
Another tumor suppressor gene located at 6q24–25 is
LATS1 (large tumor suppressor 1), which suppresses tumorigenesis by regulating cell proliferation and modulating cell survival (43). Xia et al demonstrated that transduction of recombinant LATS1 adenovirus to the MCF-7
human breast cancer cell line inhibited cell proliferation
and suppressed colony-forming ability in soft agar as well
as tumor development in nude mice (44). Therefore, the
human LATS1 gene may also play an important role in
suppressing tumor formation in humans (43, 44).
A third interesting tumor suppressor gene located at
6q24–25 is ZAC (zinc finger C2 protein), also named
LOT1 (45). It encodes a zinc finger protein, which displays antiproliferative properties through pathways central to the activity of p53, and inhibits tumor cell growth
through induction of apoptotic cell death and G1 arrest
(45, 46). ZAC is expressed in human pituitary gland, kidney, adrenal gland, liver, whole brain, and spinal cord, as
well as in mouse in brainstem and cerebellum. Reduced
ZAC expression has been shown in breast cancer cell
lines and primary tumors (47). The possible role of these
tumor suppressor genes in hemangioblastomas remains to
be clarified, but since our results indicate 6q losses
(shown by both LOH and CGH) to be so frequent, it is
tempting to speculate that the loss of function of one or
more of these suppressor genes is of importance in the
tumorigenesis of hemangioblastomas.
On chromosome 3p, we observed LOH with several
markers spanning large regions of the chromosomal arm.
The results are similar to those obtained previously on
RCCs (27). Our combined LOH and CGH data indicate
that 3p, in addition to 6q, is a characteristic site of allele
loss in hemangioblastomas
In this study, concomitant LOH on 6q and 3p was observed in a majority (67%) of the tumors. This observation was even more common in sporadic tumors, as
82% of the sporadic tumors had LOH on both 3p and 6q.
This suggests that tumorigenesis in most hemangioblastomas—and perhaps in sporadic ones in particular—may
be dependent on the inactivation of genes located in both
6q and 3p. These results are in concordance with the
recent findings of Gijtenbeek et al, who suggested that
the molecular mechanisms underlying sporadic and familial hemangioblastomas may be different (48). However, in the present study, 3p loss was more common in
sporadic hemangioblastomas than previously reported,
thus suggesting its role in the tumorigenesis of sporadic
tumors also.
In conclusion, this study is the first to report frequent
LOH on 6q in hemangioblastomas with a minimal 3-Mb
deleted region detected at 6q23–24. This region most
likely contains one or more tumor suppressor gene(s),
which may have relevance in the development and progression of a wide variety of tumor types. As all major
tumor types occurring in VHL patients (renal cell carcinomas, pheochromocytomas, and endocrine pancreatic
tumors) frequently exhibit 3p and 6q losses, this may
indicate a common tumorigenic pathway for all VHLassociated tumors.
ACKNOWLEDGMENTS
We thank Ms. Satu-Marja Snellman, MSc, for secretarial assistance,
and Ms. Tuula Suitiala, chief technician, Finnish Institute of Occupational Health, for skillful technical assistance.
REFERENCES
1. Richard S, Campello C, Taillandier L, Parker F, Resche F. Haemangioblastoma of the central nervous system in von Hippel-Lindau disease. French VHL study group. J Intern Med 1998;243:
547–53
2. Böhling T, Plate KH, Haltia MJ, Alitalo K, Neumann HPH. von
Hippel-Lindau disease and capillary haemangioblastoma. In: Kleihues P, Cavenee WK, eds. Pathology and genetics of tumours of
the nervous system. Lyon: WHO International Agency for Research
on Cancer (IARC), 2000-apter 14:223–26
3. Lindau A. Studien uber Kleinhirncysten. Bau, pathogenese und Beziehungen zur Angiomatosis Retinae. Acta Pathol Microbiol Scand
(Suppl) 1926;1:1–128
4. Decker HJH, Weidt JE, Brieger J. The von Hippel-Lindau tumor
suppressor gene. A rare and intriguing disease opening new insight
J Neuropathol Exp Neurol, Vol 63, October, 2004
1078
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
LEMETA ET AL
in to the basic mechanism of carcinogenesis. Cancer Genet Cytogenet 1997;93:74–83
Maher ER, Kaelin WG Jr. Reviews in molecular medicine. von
Hippel-Lindau disease. Medicine 1997;76:381–91
Niemelä M, Lemeta S, Summanen P, et al. Long-term prognosis of
haemangioblastoma of the CNS: Impact of von Hippel-Lindau disease. Acta Neurochir 1999;141:1147–56
Latif F, Tory K, Gnarra J, et al. Identification of the von Hippel–
Lindau disease tumor suppressor gene. Science 1993;260:1317–
20
Zbar B, Kaelin W, Maher E, Richard S. Third international meeting on von Hippel-Lindau disease. Cancer Res 1999;59:2251–
53
Maher ER, Yates JRW, Ferguson-Smith MA. Statistical analysis of
the two stage mutation model in von Hippel-Lindau disease and in
sporadic cerebellar haemangioblastoma and renal cell carcinoma. J
Med Genet 1990;27:311–14
Gläsker S, Bender BU, Apel TW, et al. Reconsideration of bialellic
inactivation of the VHL tumour suppressor gene in hemangioblastomas of the central nervous system. J Neurol Neurosurg Psychiatry
2001;70:644–48
Kanno H, Kondo K, Ito S, et al. Somatic mutations of the von
Hippel-Lindau tumor suppressor gene in sporadic hemangioblastomas central nervous system. Cancer Res 1994;54:4845–47
Lee JY, Dong SM, Park WS, et al. Loss of heterozygosity and
somatic mutation of the VHL tumor suppressor gene in sporadic
cerebellar hemangioblastomas. Cancer Res 1998;58:504–8
Tse JYM, Wong JHC, Lo KW, Poon WS, Huang DP, Ng HK. Molecular genetic analysis of the von Hippel-Lindau disease tumor
suppressor gene in familial and sporadic cerebellar hemangioblastomas. Am J Clin Pathol 1997;107:459–66
Prowse AH, Webster AR, Richards FM, et al. Somatic inactivation
of the VHL gene in von Hippel-Lindau disease tumors. Am J Hum
Genet 1997;60:765–71
Lemeta S, Aalto Y, Niemelä M, et al. Recurrent DNA sequence
copy losses on chromosomal arm 6q in capillary hemangioblastoma. Cancer Genet Cytogenet 2002;133:174–78
Sprenger SHE, Gijtenbeek JMM, Wesseling P, et al. Characteristic
chromosomal aberrations in sporadic cerebellar hemangioblastomas
revealed by comparative genomic hybridization. J Neuro-Oncology
2001;52:241–47
Colitti CV, Rodabaugh KJ, Welch WR, Berkowitz RS, Mok SC. A
novel 4 cM minimal deletion unit on chromosome 6q25.1-q25.2
associated with high grade invasive epithelial ovarian carcinomas.
Oncogene 1988;16:555–59
Merlo A, Gabrielson E, Mabry M, Vollmer R, Baylin SB, Sidransky
D. Homozygos deletion on chromosome 9p and loss of heterozygosity on 9q, 6p, and 6q in primary human small cell lung cancer.
Cancer Res 1994;59:2322–26
Pathak S, Drwinga HL, Hsu TC. Involvement of chromosome 6
rearrangements in human malignant melanoma cell lines. Cytogenet
Cell Genet 1983;36:573–79
Thomas GA, Raffel C. Loss of heterozygosity on 6q, 16q, and 17p
in human central nervous system primitive neuroectodermal tumors. Cancer Res 1991;51:639–43
Khan J, Parsa NZ, Harada T, Meltzer PS, Carter NP. Detection of
gains and losses in 18 meningiomas by comparative genomic hybridization. Cancer Genet Cytogenet 1998;103:95–100
Lamszus K, Vahldiek F, Mautner V-F, et al. Allelic losses in neurofibromatosis 2-associated meningiomas. J Neuropathol Exp
Neurol 2000;59:504–12
Kim DH, Mohapatra G, Bollen A, Waldman FM, Feuerstein BG.
Chromosomal abnormalities in glioblastoma multiforme tumors and
glioma cell lines detected by comparative genomic hybridization.
Int J Cancer 1995;60:812–19
J Neuropathol Exp Neurol, Vol 63, October, 2004
24. Kros JM, Van Run, PRWA, Alers JC, et al. Genetic aberrations in
oligodendroglial tumors: An analysis using comparative genomic
hybridization. J Pathol 1999;188:282–88
25. Alimov A, Kosti-Alimova M, Liu J, et al. Combined LOH/CGH
analysis proves the existence of interstitial 3p deletions in renal cell
carcinoma. Oncogene 2000;19:1392–99
26. Bissig H, Richter J, Desper R, et al. Evaluation of the clonal
relationship between primary and metastasic renal cell carcinoma
by comparative genomic hybridization. Am J Pathol 1999;155:
267–74
27. Morita R, Ishikawa J, Tsutsumi M, et al. Allelotype of renal cell
carcinoma. Cancer Res 1991;51:820–23
28. Thrash-Bingham CA, Greenberg RE, Howard S, et al. Comprehensive allelotyping of human renal cell carcinoma using microsatellite
DNA probes. Proc Natl Acad Sci USA 1995;92:2854–58
29. Dannenberg H, Speel EJM, Zhao J, et al. Losses of chromosome
1p and 3q are early genetic events in the development of sporadic
pheochromocytomas. Am J Pathol 2000;157:353–59
30. Barghorn A, Speel EJM, Farspour B, et al. Putative tumor suppressor loci at 6q22 and 6q23-q24 are involved in the malignant
progression of sporadic endocrine pancreatic tumors. Am J Pathol
2001;158:1903–11
31. Theile M, Seitz S, Arnold W, et al. Defined chromosome 6q fragment (at D6S310) harbors a putative tumor suppressor gene for
breast cancer. Oncogene 1996;13:677–85
32. Wan M, Sun T, Vyas R, Zheng J, Granada E, Dubeau L. Suppression of tumorigenicity in human ovarian cancer cell lines is controlled by a 2 cM fragment in chromosomal region 6q24–25. Oncogene 1999;18:1545–51
33. Foulkes WD, Ragoussis J, Stamp GWH, Allan GJ, Trowsdale J.
Frequent loss of heterozygosity on chromosome 6 in human ovarian
carcinoma. Br J Cancer 1993;67:551–59
34. Saito S, Saito H, Koi S, et al. Fine scale deletion mapping of the
distal long arm of chromosome 6 in 70 human ovarian cancers.
Cancer Res 1992;52:5815–17
35. Shridhar V, Staub J, Huntley B, et al. A novel region of deletion
on chromosome 6q23.3 spanning less than 500Kb in high-grade
invasive epithelial ovarian cancer. Oncogene 1997;18:3913–18
36. Tibiletti MG, Bernasconi B, Furlan D, et al. Chromosome 6 abnormalities in ovarian surface epithelial tumors of borderline malignancy suggest a genetic continuum in the progression model of
ovarian neoplasms. Clin Cancer Res 2001;7:3404–09
37. Millikin D, Meese E, Vogelstein B, Witkowski C, Trent J. Loss of
heterozygosity for loci on the long arm of chromosome 6 in human
malignant melanoma. Cancer Res 1991;51:5449–53
38. Srikantan V, Sesterhenn IA, Davis L, et al. Allelic loss on chromosome
6q in primary prostate cancer. Int J Cancer 1999;84:331–35
39. Acevedo CM, Henriquez M, Emmert-Buck MR, Chuaqui RF. Loss
of heterozygosity on chromosome arms 3p and 6q in microdissected
adenocarcinomas of the uterine cervix and adenocarcinoma in situ.
Cancer 2002;94:793–802
40. Hildebrandt T, Preiherr J, Tarbe N, Klostermann S, Van Muen GNP,
Weidle UH. Identification of THW, a putative new tumor suppressor
gene. Anticancer Res 2000;20:2801–10
41. Miele EM, Jewett DM, Goldberg FS, et al. A human melanoma
metastasis-suppressor locus maps to 6q16.3-q23. Int J Cancer 2000;
86:524–28
42. Hildebrandt T, van Dijk MCRF, Van Muijen GNP, Weidle UH. Loss
of heterozygosity of gene THW is frequently found in melanoma
metastases. Anticancer Res 2001;21:1071–80
43. St John MAR, Tao W, Fei X, et al. Mice deficient of LATS1 develop soft-tissue sarcomas, ovarian tumors and pituitary dysfunction. Nature Genet 1999;21:182–86
44. Xia H, Qi H, Li Y, et al. LATS1 tumor suppressor regulates G2/M
transition and apoptosis. Oncogene 2002;21:1233–41
LOH AT 6q IN CAPILLARY HEMANGIOBLASTOMAS
45. Abdollahi A, Roberts D, Godwin AK, et al. Identification of a zinc
finger gene at 6q25: A chromosomal region implicated in development of many solid tumors. Oncogene 1997;14:1973–79
46. Varrault A, Ciani E, Apiou F, et al. hZAC encodes a zinc finger
protein with antiproliferative properties and maps to a chromosomal
region frequently lost in cancer. Proc Natl Acad Sci USA 1998;95:
8835–40
47. Bilanges B, Varrault A, Basyuk E. Loss of expression of the candidate tumor suppressor gene ZAC in breast cancer cell lines and
primary tumors. Oncogene 1999;18:3979–88
1079
48. Gijtenbeek JM, Jacobs B, Sprenger SH. Analysis of von HippelLindau mutations with comparative genomic hybridization in sporadic and hereditary hemangioblastomas: Possible genetic heterogeneity. J Neurosurg 2002;97:977–82
Received October 20, 2003
Revision received April 19, 2004
Accepted July 2, 2004
J Neuropathol Exp Neurol, Vol 63, October, 2004