A novel mutation in the juxtamembrane intracellular sequence of the granulocyte colony-stimulating factor (G-CSF) receptor gene in a patient with severe congenital neutropenia augments GCSF proliferation activity but not through the MAP kinase cascade
| Autor: | Yuichi Sekine, Mine Harada, Kenjirou Kamezaki, Taisuke Kanaji, Koutarou Shide, Haruko Kakumitsu, Jun Okamura, Akihiko Numata, Seiichi Okamura, Tadashi Matsuda, Hitoshi Nakashima, Yoshiyuki Niho, Toshihiro Yokoyama, Yumi Mizuno, Kazuya Shimoda, Yoshinobu Asano |
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| Rok vydání: | 2005 |
| Předmět: |
Neutropenia
MAP Kinase Signaling System Mutant Biology medicine.disease_cause Tropomyosin receptor kinase C medicine Humans Receptor Child Frameshift Mutation History Ancient Cell Proliferation Mutation Leukemia Point mutation Wild type Hematology DNA Syndrome Cell Transformation Neoplastic Interleukin-21 receptor Receptors Granulocyte Colony-Stimulating Factor Cancer research Female Granulocyte colony-stimulating factor receptor Signal Transduction |
| Zdroj: | International journal of hematology. 82(1) |
| ISSN: | 0925-5710 |
| Popis: | We analyzed the structure of the granulocyte colony-stimulating factor (G-CSF) receptor gene in a 6-year-old female patient with severe congenital neutropenia (SCN) who experienced severe recurrent infections since 1 month of age. There is no family history of any similar disease. When the patient was 4 months old, she began receiving treatment with recombinant human G-CSF that resulted in a small increase in the neutrophil count sufficient for the prevention and treatment of bacterial infection. An analysis of complementary DNA for the patient's G-CSF receptor revealed a 3-base pair deletion in the juxtamembrane intracellular sequence. This deletion at the beginning of exon 16 was thought to be caused by alternative splicing; analysis of the DNA revealed a G-to-A point mutation of the final nucleotide of intron 15. To evaluate the functional activity of the G-CSF receptor with this 3-base pair deletion of the juxtamembrane region, we transfected this G-CSF receptor mutant into an interleukin 3-dependent cell line, BAF/3. BAF/3 cells expressing the mutant G-CSF receptor showed augmented proliferation activity in response to G-CSF compared with cells having the wild-type G-CSF receptor. Although the proliferation signal of G-CSF in normal hematopoiesis is transduced through the activation of MAP kinases, this G-CSF receptor mutant showed decreased activation of ERKI/2 in response to G-CSF compared with the wild type, but the transduced sig-nal for Stat3 activation by G-CSF was of the same magnitude as that of the wild-type G-CSF receptor. This result means that the augmented proliferation activity in response to G-CSF that we observed in cells having the G-CSF receptor gene with the 3-base pair deletion is transduced through an intracellular signaling pathway other than MAP kinase. Because SCN patients with a mutation in the G-CSF receptor frequently develop leukemia, this 3-base pair deletion in the juxtamembrane sequence of the G-CSF receptor gene in this patient may be one step in the course of leukemic transformation. |
| Databáze: | OpenAIRE |
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