| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Advances in Brief |
Departments of Radiation Biology [T. H., M. S., R. B., T. N.], Pathology [T. L., K. A.], and Hemato-Oncology [H. I., Y. K.], Faculty of Medicine, Osaka University, Osaka 565-0871, Japan
| ABSTRACT |
|---|
|
|
|---|
| Introduction |
|---|
|
|
|---|
The c-kit proto-oncogene encodes a receptor of tyrosine
kinase, which is essential to hematopoiesis, and recently, the
development of acute leukemia or malignant lymphoma was reported in
transgenic mice expressing KITV814 (Asp814
Val;
Ref. 7
). Consequently, sinonasal NKTCLs in two high
incidence regions of Beijing (China) and Osaka (Japan) were examined
for the c-kit gene mutation.
| Materials and Methods |
|---|
|
|
|---|
|
The PCR primer pairs for the amplification of the c-kit gene exons 11 and 17 were as follows: 5'-GATCTATTTTTCCCTTTCTC-3' and 5'-AGCCCCTGTTTCATACTGAC-3' for exon 11; 5'-CATGGTCGGATCACAAAGAT-3' and 5'-ATTATGAAAGTCACGGAAAC-3' for exon 17. DNA amplification and nonradioactive SSCP (Cold SSCP) analysis were carried out to detect mutations as described previously (8 , 9) . The mutated SSCP bands were extracted from the gel and reamplified by PCR for 25 cycles to enrich mutated alleles.
Sequencing was performed by the dideoxy chain termination method using the Big Dye terminator cycle sequencing kit (Perkin-Elmer, Foster City, CA). Sequencing primers were the same as those used for PCR. Cycle sequencing was performed following the protocol, i.e., 30 cycles of denaturation (95°C for 30 s), annealing (54°C for 30 s) and extension (72°C for 3 min) followed by cooling at 20°C after the final cycle. After ethanol precipitation, the samples were analyzed by the Genetic Analyzer (ABI PRISM 310; Perkin-Elmer, Foster City, CA). PCR-SSCP analyses and sequencing of mutated bands were repeated three times for each sample to rule out the possibility of contamination and PCR fidelity artifacts. As controls, c-kit mutations in peripheral blood mononuclear cells were examined in 10 healthy Japanese and 10 Chinese (12 males and 8 females; median age, 30 years; range, 2447 years) living in Osaka.
Site-directed Mutagenesis and Transfection.
To directly examine the causal role of the c-kit mutations
in activation of c-kit tyrosine kinase activity,
site-directed mutagenesis was performed using murine c-kit
cDNA as described previously (10)
. Briefly, the expression
vectors containing wild-type and mutated c-kit cDNA
[Ala-823, which was constructed by site-directed mutagenesis to
correspond to human c-kitR (Ala-825)] were transfected into
the human embryonic kidney cell line 293T by the calcium phosphate
method. The cells were cultured in DMEM containing 10% FCS and
fed every 3 days with fresh medium. To determine the expression of
c-kit product in the transfected 293T cells, the
transfectants were incubated with
[35S]methionine (3.7 x 106 Bq/ml; DuPont/NEN research Products) for
6 h and lysed with NP 40 lysis buffer. The labeled
c-kit product was then immunoprecipitated with a rat
antimouse c-kit mAb (mAb ACK-2; kindly provided by Dr. S-I.
Nishikawa, Kyoto University, Kyoto, Japan) and analyzed by SDS-PAGE and
autoradiography. To examine the activation and tyrosine phosphorylation
of c-kit product, the c-kit product of each
transfectant was immunoprecipitated with rabbit antiserum against
murine c-kit protein from the lysates, and then subjected to
in vitro immune complex kinase assay and immunoblotting with
an antiphosphotyrosine mAb as described above.
| Results and Discussion |
|---|
|
|
|---|
As shown in Table 1
, 10 of 14 Chinese sinonasal lymphoma cases (71.4%)
showed mutations at exon 11 (3 cases, 21.4%) and exon 17 (7 cases,
50.0%), whereas only 2 of 9 Japanese cases (22.2%) had mutations at
exon 11 (1 case, 11.1%) and exon 17 (1 case, 11.1%;
P < 0.05 by Fishers exact test).
Furthermore, mutations occurred at highly restricted sites. Seven of
eight c-kit mutations in exon 17 occurred at codon 825
(GTT
GCT; Val
Ala), and three of four mutations in exon 11 occurred
at codon 561 [two GAG
AAG (Glu
Lys); one silent GAG
GAA
(Glu
Glu)]. All of 12 mutations were caused by single-nucleotide
substitutions. Among them, 11 were missense mutations leading to amino
acid substitution, and the other was a silent mutation without any
amino acid changes. Seven of the 12 (58.3%) single-nucleotide
substitution were A:T to G:C transitions, and the remainders (41.7%)
were G:C to A:T transitions. Transversion was not detected in the
present cases, and no mutations involved CpG dinucleotides.
The c-kit gene is the cellular homologue of the viral
oncogene, and several studies have suggested that a mechanism of
stromal/parenchymal interactions via the c-kit
receptor-ligand system might be involved in normal hematopoiesis,
gametogenesis, and melanogenesis (11, 12, 13)
. In the present
study, 10 of 12 c-kit mutations were detected at codons 825
and 561. Such hot spots were not reported in any of the earlier studies
of human and animal neoplasms. However, mutations of the
c-kit gene at codon 816 are known to cause substitution of
tyrosine or valine for aspartate in mast cells derived from patients
with mastocytosis and urticaria pigmentosa (14
, 15)
. The
protein product of the c-kit gene is a tyrosine kinase
receptor that consists of four parts, i.e., the
extracellular, transmembrane, juxtamembrane, and tyrosine kinase
domains. Both codons 816 and 825 are located on the tyrosine kinase
domain. A mutation in codon 560 (Val
Gly) on the juxtamembrane domain
was also reported to cause constitutive phosphorylation and activation
of KIT in human gastrointestinal stromal tumors (10
, 16, 17, 18)
. These mutations can transform cell lines from
factor-dependent growth to factor-independent growth (16
, 18, 19, 20)
.
To determine whether KITA825 is a gain-of-function mutation, a mutated murine c-kit gene encoding murine c-kitR (Ala-823) was constructed by site-directed mutagenesis corresponding to human c-kitR (Ala-825) and transfected into a human embryonic kidney cell line. In the transfected cells, wild-type c-kitR and mutant c-kitR (Ala-823) were neither phosphorylated on tyrosine nor activated in an immunocomplex kinase reaction in the absence of stem cell factor. KITA825, frequently observed in our cases with sinonasal NKTCL, is not a gain-of-function mutation.
In the present study, analysis of sinonasal NKTCL from China and Japan shows that the occurrence of specific c-kit substitution mutations and the spectrum of c-kit mutations (codons 651 and 825) are very similar in China and Japan. However, the mutation frequency was significantly different between the two Asian populations. The difference may be caused by the migration of susceptible populations or some environmental confounding factors that produce specific mutations. Additional studies on the c-kit and other mutations in China and Japan will be necessary to understand the difference in oncogenesis of NKTCL.
| FOOTNOTES |
|---|
1 This work was supported by grants from the
Japanese Ministry of Education, Science and Culture, and from Research
for the Future of JSPS. ![]()
2 To whom requests for reprints should be
addressed, at Department of Pathology (C3), Faculty of Medicine, Osaka
University, 2-2 Yamada-Oka, Suita, Osaka 565-0871, Japan. Phone:
81-6-879-3710; Fax: 81-6-879-3713; E-mail: aozasa{at}molpath.med.osaka-u.ac.jp ![]()
3 The abbreviations used are: NKTCL, natural
killer/T-cell lymphoma; SSCP, single-strand conformation polymorphism;
mAb, monoclonal antibody. ![]()
Received 11/18/99. Accepted 3/16/00.
| REFERENCES |
|---|
|
|
|---|
This article has been cited by other articles:
![]() |
J. Sun, M. Pedersen, and L. Ronnstrand The D816V Mutation of c-Kit Circumvents a Requirement for Src Family Kinases in c-Kit Signal Transduction J. Biol. Chem., April 24, 2009; 284(17): 11039 - 11047. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. M. Benson Jr, J. Yu, B. Becknell, M. Wei, A. G. Freud, A. K. Ferketich, R. Trotta, D. Perrotti, R. Briesewitz, and M. A. Caligiuri Stem cell factor and interleukin-2/15 combine to enhance MAPK-mediated proliferation of human natural killer cells Blood, March 19, 2009; 113(12): 2706 - 2714. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. P. Zappulla, P. Dubreuil, S. Desbois, S. Letard, N. B. Hamouda, M. Daeron, G. Delsol, M. Arock, and R. S. Liblau Mastocytosis in mice expressing human Kit receptor with the activating Asp816Val mutation J. Exp. Med., December 19, 2005; 202(12): 1635 - 1641. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Sihto, M. Sarlomo-Rikala, O. Tynninen, M. Tanner, L. C. Andersson, K. Franssila, N. N. Nupponen, and H. Joensuu KIT and Platelet-Derived Growth Factor Receptor Alpha Tyrosine Kinase Gene Mutations and KIT Amplifications in Human Solid Tumors J. Clin. Oncol., January 1, 2005; 23(1): 49 - 57. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. L. Corless, J. A. Fletcher, and M. C. Heinrich Biology of Gastrointestinal Stromal Tumors J. Clin. Oncol., September 15, 2004; 22(18): 3813 - 3825. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Kemmer, C. L. Corless, J. A. Fletcher, L. McGreevey, A. Haley, D. Griffith, O. W. Cummings, C. Wait, A. Town, and M. C. Heinrich KIT Mutations Are Common in Testicular Seminomas Am. J. Pathol., January 1, 2004; 164(1): 305 - 313. [Abstract] [Full Text] [PDF] |
||||
![]() |
H-P Horny, K Lange, K Sotlar, and P Valent Increase of bone marrow lymphocytes in systemic mastocytosis: reactive lymphocytosis or malignant lymphoma? Immunohistochemical and molecular findings on routinely processed bone marrow biopsy specimens J. Clin. Pathol., August 1, 2003; 56(8): 575 - 578. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Sotlar, L. Escribano, O. Landt, S. Mohrle, S. Herrero, A. Torrelo, U. Lass, H.-P. Horny, and B. Bultmann One-Step Detection of c-kit Point Mutations Using Peptide Nucleic Acid-Mediated Polymerase Chain Reaction Clamping and Hybridization Probes Am. J. Pathol., March 1, 2003; 162(3): 737 - 746. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Frost, J. Lasota, and M. Miettinen Gastrointestinal Stromal Tumors and Leiomyomas in the Dog: A Histopathologic, Immunohistochemical, and Molecular Genetic Study of 50 Cases Vet. Pathol., January 1, 2003; 40(1): 42 - 54. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. J. Frost, P. T. Ferrao, T. P. Hughes, and L. K. Ashman Juxtamembrane Mutant V560GKit Is More Sensitive to Imatinib (STI571) Compared with Wild-Type c-Kit Whereas the Kinase Domain Mutant D816VKit Is Resistant Mol. Cancer Ther., October 1, 2002; 1(12): 1115 - 1124. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. C. Heinrich, C. D. Blanke, B. J. Druker, and C. L. Corless Inhibition of KIT Tyrosine Kinase Activity: A Novel Molecular Approach to the Treatment of KIT-Positive Malignancies J. Clin. Oncol., March 15, 2002; 20(6): 1692 - 1703. [Abstract] [Full Text] [PDF] |
||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Cancer Research | Clinical Cancer Research |
| Cancer Epidemiology Biomarkers & Prevention | Molecular Cancer Therapeutics |
| Molecular Cancer Research | Cancer Prevention Research |
| Cancer Prevention Journals Portal | Cancer Reviews Online |
| Annual Meeting Education Book | Meeting Abstracts Online |