BACKGROUNDHuman piebaldism is a rare autosomal dominant condition characterized by congenital white forelock and depigmented patches of skin, typically on the forehead, anterior trunk and extremities. Mutations in the KIT gene have been proposed to be responsible for the underlying changes in this disorder. The aim of this study was to identify gene mutation in a Chinese family with piebaldism.

METHODSA Chinese family with piebaldism presenting with white forelock and large depigmented skin macules on the abdomen, arms and legs was collected. DNA was isolated from peripheral blood of the family members. The encoding exons with flanking intron regions of the KIT gene were analyzed by polymerase chain reactions (PCR) and direct DNA sequencing. Besides, DNA extracted from 100 ethnically matched population individuals was as controls.

RESULTSA heterozygous missense mutation c.2590T > C was identified in the patients of the family. This mutation converted a serine residue to proline (p.Ser864Pro). The mutation was not found in their unaffected family members or normal controls.

CONCLUSIONA novel missense mutation c.2590 T > C was found and it might play a significant role in the piebaldism phenotype in the family.

Child ; Humans ; Male ; Mutation, Missense ; Piebaldism ; genetics ; Proto-Oncogene Proteins c-kit ; genetics ; physiology

Gastrointestinal Stromal Tumors/pathology* ; Humans ; Proto-Oncogene Proteins c-kit/genetics*

OBJECTIVETo define the frequency and spectrum of c-kit gene mutations in gastrointestinal stromal tumors (GIST).

METHODSFifty two cases of GIST and 28 cases of other tumors were examined for mutations in exon 11, 9 and 13 of c-kit gene using PCR amplification and DNA sequencing.

RESULTSFourteen out of 25 malignant GIST (56%), while 2 of 27 benign and borderline GIST (7.4%) revealed mutations in exon 11 of c-kit gene (P < 0.01). Most of the mutations consisted of in-frame deletion or replication from 3 to 48 bp in heterozygous and homozygous fashions, but none of the mutations disrupted the downstream reading frame of the gene. Point mutation and deletion concentrated at 550 - 570 codons but replication clustered within 570 - 585 codons. The mutation pattern in recurrence tissues was the same as the primary ones. Normal tissues adjacent to GIST with or without c-kit gene mutations showed wild type c-kit gene sequence. No mutation was found in exon 9 and 13. Neither c-kit gene expression nor gene mutations was found in 3 leiomyomas, 8 leiomyosarcomas, 2 schwannomas, 2 intra-abdomenal fibromitoses and 8 adenocarcinomas.

CONCLUSIONThe mutations in exon 11 of c-kit gene might partially represent one of the molecular mechanisms of GIST. It can be used as a marker for distinguishing benignancy and malignancy of GIST. The mutations did not involve the reading frame. Except for long frame deletion, most mutations also did not affect protein expression. Mutation of c-kit gene in GIST provides a new genotypic marker to distinguish GIST from authentic leiomyomas, leiomyosarcomas, schwannomas and etc.

Base Sequence ; Gastrointestinal Neoplasms ; genetics ; Humans ; Molecular Sequence Data ; Mutation ; Proto-Oncogene Proteins c-kit ; analysis ; genetics ; Proto-Oncogenes

The aim of this study was to investigate the effect of microRNA-193b (miR-193b) on C-KIT protein expression and biological behaviors in K562 cells. The FAM-labeled miR-193b mimic and negative control were respectively transfected into K562 cells using HiPerFect transfection reagent. The percentage of FAM-positive cells was monitored by flow cytometry. The levels of C-KIT and phosphorylated C-KIT protein were detected by Western blot. The cell growth was measured by CCK-8 reagent. The apoptosis of cells were analyzed by flow cytometry with Annexin V staining. The differentiation of cells were analyzed by flow cytometry with anti-CD11b or anti-CD15 staining. The results demonstrated that the percentage of FAM-positive cells was about 80% in miR-193b or negative control-transfected K562 cells. Compared with the negative control group, overexpression of miR-193b in K562 cells significantly inhibited the levels of C-KIT and phosphorylated C-KIT protein. Meanwhile, the cell growth was inhibited and the percentages of apoptotic cells, CD11b- or CD15-positive cells increased. It is concluded that miR-193b can reduce C-KIT expression and inhibit cell growth in K562 cells. The growth-inhibitory activity of miR-193b is associated with apoptosis and granulocytic differentiation. This study contributed to further investigate the role of miR-193b in leukemogenesis.
Cell Differentiation ; genetics ; Cell Proliferation ; Humans ; K562 Cells ; MicroRNAs ; genetics ; Proto-Oncogene Proteins c-kit ; genetics ; metabolism ; Transfection

Gastrointestinal stromal tumors(GIST) are known for their molecular alterations in KIT or PDGFR genes, and have become the paradigm of molecularly targeted therapies for solid tumors. Recent researches of genotype and phenotype demonstrate that molecular subtypes can predict the response to treatment with tyrosine kinase inhibitors and are related with prognosis. Different strategies will be recommended according to different molecular subtypes of GIST in the future for treatment optimization and individualization.
Gastrointestinal Neoplasms ; genetics ; therapy ; Gastrointestinal Stromal Tumors ; genetics ; therapy ; Genotype ; Humans ; Prognosis ; Proto-Oncogene Proteins c-kit

Adult ; Exons ; Female ; Gastrointestinal Stromal Tumors ; genetics ; metabolism ; pathology ; Gene Deletion ; Humans ; Proto-Oncogene Proteins c-kit ; genetics ; metabolism

The most common problem in the diagnosis of gastrointestinal stromal tumor (GIST) is inadequate specimen fixation. The paper focused on specimen fixation and standardized protocol in immunohistochemistry staining and gene mutation detection. We have adjusted some procedure used in immunohistochemistry staining and c-kit gene detection to improve the quality of inadequately fixed specimen. It maybe useful for clinicians, pathologists and technicians working in immunohistochemistry labs and gene detection labs.
Gastrointestinal Stromal Tumors ; diagnosis ; pathology ; Humans ; Immunohistochemistry ; Mutation ; Proto-Oncogene Proteins c-kit ; genetics ; Specimen Handling ; Staining and Labeling

Animals ; Bufo bufo ; Caspase 3 ; genetics ; metabolism ; Female ; Immunohistochemistry ; Male ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; metabolism ; Proto-Oncogene Proteins c-kit ; genetics ; metabolism ; Spinal Cord ; metabolism ; Spinal Cord Injuries ; metabolism ; bcl-2-Associated X Protein ; genetics ; metabolism

Mutation of c-kit and platelet-derived growth factor receptor alpha (PDGFRA) is the most important molecular feature of gastrointestinal stromal tumor (GIST). Mutation detection of these two genes is of great significance when establishing the diagnosis of a kit-negative GIST, or when predicting response to tyrosine kinase inhibitor. Furthermore, more and more researches focus on the feasibility of the mutation status using as a prognostic factor in recent years.
Gastrointestinal Neoplasms ; diagnosis ; drug therapy ; genetics ; Gastrointestinal Stromal Tumors ; diagnosis ; drug therapy ; genetics ; Humans ; Mutation ; Proto-Oncogene Proteins c-kit ; genetics ; Receptor, Platelet-Derived Growth Factor alpha ; genetics

t(8;21)(q22;q22) acute myeloid leukemia (AML) is a highly heterogeneous hematological malignancy with a high relapse rate in China. Two leukemic myeloblast populations (CD34
Gene Expression ; Granulocyte Precursor Cells ; Humans ; Immunophenotyping ; Leukemia, Myeloid, Acute/genetics* ; Membrane Glycoproteins ; Prognosis ; Proteins ; Proto-Oncogene Proteins c-kit/genetics*