This study was aimed to investigate the abnormal expression of PDGFRA gene in eosinophilia by FISH. Translocations of PDGFRA gene in 13 patients with eosinophilia were detected by using 4q12 three-color probe and FISH technology. Fifteen people were used as control to establish the normal cut-off value of fluorescence signal of PDGFRA. The results indicated that 1 out of 13 patients with eosinophilia was corrected and was diagnosed as CML. The fusion gene of FIP1L1-PDGFRA (F/P) was found in 2 patients and the positive rate of F/P fusion gene detected by probe 4q12 was 17% in the 12 patients with eosinophilia. Other translocation forms involving PDGFRA gene were not found. It is concluded that a variety of translocation forms of PDGFRA gene can be detected in patients with eosinophilia by using 4q12 three-color probe and FISH technology, which can provide important information for assessing diagnosis and treatment.
Chromosomes, Human, Pair 4 ; Eosinophilia ; metabolism ; Humans ; In Situ Hybridization, Fluorescence ; Oncogene Proteins, Fusion ; Receptor, Platelet-Derived Growth Factor alpha ; genetics ; Translocation, Genetic

OBJECTIVETo investigate the relationship between secondary mutations of c-kit/PDGFRα resistance to imatinib mesylate and the efficacy of sunitinib in patients with gastrointestinal stromal tumor (GIST).

METHODSFive pairs specimens were collected before and after imatinib mesylate resistance. DNA for molecular genetic investigation was extracted from formalin-fixed, paraffin-embedded tissues. Mutational analysis was performed by using PCR and direct sequencing.

RESULTSFive pairs of specimens were collected before and after imatinib mesylate resistance from 5 GIST patients. C-kit exon 11 mutations were detected in 3 patients, which were all acquired mutations, including c-kit exon 13 V654A, c-kit exon 13 V654E and c-kit exon 17 N822K, after imatinib mesylate resistance. Furthermore, after sunitinib treatment, 3 patients had stable disease and progression free survival (PFS) were 3.5 months, 4.4 months and 3.8 months, respectively. C-kit exon 9 mutations were detected in 2 patients with no acquired mutations after imatinib mesylate resistance. And the both had partial response from sunitinib, following with 13.1 months and 12.0 months PFS respectively.

CONCLUSIONThe c-kit/PDGFRα genotypes after imatinib mesylate resistance may both relate to primary mutations and efficacy of sunitinib treatment.

Antineoplastic Agents ; therapeutic use ; Benzamides ; Disease-Free Survival ; Drug Resistance, Neoplasm ; Exons ; Female ; Gastrointestinal Stromal Tumors ; drug therapy ; genetics ; Genotype ; Humans ; Imatinib Mesylate ; Indoles ; therapeutic use ; Male ; Middle Aged ; Mutation ; Piperazines ; therapeutic use ; Proto-Oncogene Proteins c-kit ; genetics ; metabolism ; Pyrimidines ; therapeutic use ; Pyrroles ; therapeutic use ; Receptor, Platelet-Derived Growth Factor alpha ; genetics ; metabolism

OBJECTIVETo study the clinical and pathologic features of gastric schwannomas.

METHODSThe macroscopic and microscopic features of 9 cases of gastric schwannoma were analyzed. Immunohistochemical study for S-100 protein, CD117, CD34, neurofilament, desmin, nestin, glial fibrillary acidic protein, platelet derived growth factor-alpha (PDGFR-α) and vimentin was carried out. Mutation analysis of c-kit gene (exon 9, 11, 13 and 17) and PDGFR-α gene (exon 12 and 18) in 1 case was examined by PCR amplification and direct sequencing.

RESULTSThe patients included 5 males and 4 females. The age of patients ranged from 42 to 81 years (median = 56.5 years). The size of the tumors ranged from 2 to 9 cm in greatest diameter. Follow-up data in 8 cases (from 1 month to 65 months) showed no evidence of recurrence or metastasis. Gross examination showed that gastric schwannomas were homogeneous, firm, yellow-white and bore no true fibrous capsule. Histologically, all cases were composed of fascicles of spindle cells associated with nuclear palisading, Verocay body formation and peripheral cuff of reactive lymphoid aggregates. Some of them showed degenerative changes including cyst formation, calcification, hemorrhage, necrosis and hyalinization. Immunohistochemical study showed that the tumor cells were strongly positive for S-100 protein and vimentin. There was various degree of staining for nestin (8/9) and glial fibrillary acidic protein (6/9). They were negative for CD117, CD34, neurofilament, desmin and smooth muscle actin. One case showed focal positivity for PDGFR-α (1/9), with no mutations found.

CONCLUSIONSGastric schwannomas share similar histologic features with conventional soft tissue schwannomas, in addition to the presence a reactive lymphoid cuff. The clinical, macroscopic, histologic and immunohistochemical features of gastric schwannomas were different from those of gastrointestinal stromal tumors and leiomyomas.

Adult ; Aged ; Aged, 80 and over ; Diagnosis, Differential ; Exons ; Female ; Follow-Up Studies ; Gastrectomy ; methods ; Gastrointestinal Stromal Tumors ; metabolism ; pathology ; Glial Fibrillary Acidic Protein ; metabolism ; Humans ; Intermediate Filament Proteins ; metabolism ; Leiomyoma ; metabolism ; pathology ; Leiomyosarcoma ; metabolism ; pathology ; Male ; Middle Aged ; Mutation ; Nerve Tissue Proteins ; metabolism ; Nestin ; Neurilemmoma ; metabolism ; pathology ; surgery ; Neurofibroma ; metabolism ; pathology ; Receptor, Platelet-Derived Growth Factor alpha ; genetics ; metabolism ; S100 Proteins ; metabolism ; Stomach Neoplasms ; metabolism ; pathology ; surgery ; Vimentin ; metabolism

Metastasis represents by far the most feared complication of prostate carcinoma and is the main cause of death for patients. The skeleton is frequently targeted by disseminated cancer cells and represents the sole site of spread in more than 80% of prostate cancer cases. Compatibility between select malignant phenotypes and the microenvironment of colonized tissues is broadly recognized as the culprit for the organ-tropism of cancer cells. Here, we review our recent studies showing that the expression of platelet-derived growth factor receptor alpha (PDGFRα) supports the survival and growth of prostate cancer cells in the skeleton and that the soluble fraction of bone marrow activates PDGFRα in a ligand-independent fashion. Finally, we offer pre-clinical evidence that this receptor is a viable target for therapy.
Animals ; Antibodies, Monoclonal ; therapeutic use ; Bone Marrow ; enzymology ; pathology ; Bone Neoplasms ; prevention & control ; secondary ; Enzyme Activation ; Humans ; Male ; Prostatic Neoplasms ; drug therapy ; enzymology ; pathology ; Receptor, Platelet-Derived Growth Factor alpha ; antagonists & inhibitors ; genetics ; immunology ; metabolism ; Signal Transduction ; Transcriptional Activation

Recent collaborative, large-scale genomic profiling of the most common and aggressive brain tumor glioblastoma multiforme(GBM) has significantly advanced our understanding of this disease. The gene encoding platelet-derived growth factor receptor alpha(PDGFRα) was identified as the third of the top 11 amplified genes in clinical GBM specimens. The important roles of PDGFRα signaling during normal brain development also implicate the possible pathologic consequences of PDGFRα over-activation in glioma. Although the initial clinical trials using PDGFR kinase inhibitors have been predominantly disappointing, diagnostic and treatment modalities involving genomic profiling and personalized medicine are expected to improve the therapy targeting PDGFRα signaling. In this review, we discuss the roles of PDGFRαsignaling during development of the normal central nervous system(CNS) and in pathologic conditions such as malignant glioma. We further compare various animal models of PDGF-induced gliomagenesis and their potential as a novel platform of pre-clinical drug testing. We then summarize our recent publication and how these findings will likely impact treatments for gliomas driven by PDGFRα overexpression. A better understanding of PDGFRα signaling in glioma and their microenvironment, through the use of human or mouse models, is necessary to design a more effective therapeutic strategy against gliomas harboring the aberrant PDGFRα signaling.
Animals ; Antineoplastic Agents ; therapeutic use ; Autocrine Communication ; Brain Neoplasms ; drug therapy ; genetics ; metabolism ; Central Nervous System ; cytology ; embryology ; metabolism ; Disease Models, Animal ; Glioblastoma ; drug therapy ; genetics ; metabolism ; Glioma ; drug therapy ; genetics ; metabolism ; Humans ; Neurons ; cytology ; metabolism ; Protein Kinase Inhibitors ; therapeutic use ; Receptor, Platelet-Derived Growth Factor alpha ; genetics ; metabolism

Over the past 60 years, investigators of basic science, pathology, and clinical medicine have studied gastrointestinal stromal tumor (GIST) and made minor advances in patient care. Recent discoveries have led to an understanding of the biological role of KIT and platelet-derived growth factor receptor-α in GIST and the development of the tyrosine kinase inhibitor imatinib mesylate (Gleevec, formerly STI-571), one of the most exciting examples of targeted therapy to date. The success of targeted therapy in GIST has lead to new developments in our understanding of the medical and surgical management of the disease. Intense study of GIST may lead to new paradigms in the management of cancer.
Antineoplastic Agents ; therapeutic use ; Benzamides ; Combined Modality Therapy ; Drug Delivery Systems ; Gastrointestinal Neoplasms ; drug therapy ; genetics ; pathology ; surgery ; Gastrointestinal Stromal Tumors ; drug therapy ; genetics ; pathology ; surgery ; Humans ; Imatinib Mesylate ; Mutation ; Piperazines ; therapeutic use ; Protein Kinase Inhibitors ; therapeutic use ; Proto-Oncogene Proteins c-kit ; genetics ; metabolism ; Pyrimidines ; therapeutic use ; Receptor, Platelet-Derived Growth Factor alpha ; genetics ; metabolism

Antigens, CD34 ; metabolism ; Carcinoma, Signet Ring Cell ; genetics ; metabolism ; pathology ; surgery ; Codon ; Diagnosis, Differential ; Exons ; Female ; Follow-Up Studies ; Gastrectomy ; methods ; Gastrointestinal Neoplasms ; genetics ; metabolism ; pathology ; surgery ; Gastrointestinal Stromal Tumors ; genetics ; metabolism ; pathology ; surgery ; Humans ; Melanoma ; metabolism ; pathology ; Middle Aged ; Neurilemmoma ; metabolism ; pathology ; Point Mutation ; Proto-Oncogene Proteins c-kit ; metabolism ; Receptor, Platelet-Derived Growth Factor alpha ; genetics ; metabolism

OBJECTIVETo study the immunophenotype and c-kit or platelet derived growth factor receptor alpha (PDGFRA) gene mutations in CD117-negative gastrointestinal stromal tumors (GISTs).

METHODSTen cases of GISTs with typical histologic features but no CD117 expression were retrieved from the archival of Department of Pathology, Peking Union Medical College Hospital, China. The cases were further evaluated for the presence of c-kit exons 9, 11, 13 and 17 mutations and PDGFRA exons 12 and 18 mutations. DNA was extracted from the paraffin-embedded tumor tissue. The PCR products were sequenced directly for the mutations. An immunohistochemical study for CD117, CD34, smooth muscle actin, desmin, S-100 protein, WT-1 and DOG-1 was also performed.

RESULTSEight of the 10 cases had the mutation tests completed. C-kit mutation in exon 9 was detected in only one case. Amongst the 10 cases studied, CD34 was expressed in 9 cases. Smooth muscle actin was focally positive in 2 cases. None of them expressed desmin or S-100 protein. DOG-1 and WT-1 were diffusely positive in 5 and 4 cases, respectively. In addition, DOG1 was diffusely but weakly positive in 1 case and focally expressed in 2 cases. Three cases were focally positive for WT-1.

CONCLUSIONPathologic diagnosis of CD117-negative GISTs can be facilitated with the application of a panel of immunohistochemical markers, including DOG-1 and WT-1.

Actins ; metabolism ; Adult ; Aged ; Anoctamin-1 ; Antigens, CD34 ; metabolism ; Chloride Channels ; Exons ; Female ; Gastrointestinal Stromal Tumors ; genetics ; metabolism ; pathology ; Humans ; Immunophenotyping ; Male ; Membrane Proteins ; metabolism ; Middle Aged ; Mutation ; Neoplasm Proteins ; metabolism ; Proto-Oncogene Proteins c-kit ; genetics ; metabolism ; Receptor, Platelet-Derived Growth Factor alpha ; genetics ; metabolism ; WT1 Proteins ; metabolism ; Young Adult

Anoctamin-1 ; Antineoplastic Agents ; administration & dosage ; Benzamides ; Biomarkers, Tumor ; metabolism ; Chloride Channels ; Drug Delivery Systems ; methods ; Gastrointestinal Neoplasms ; genetics ; metabolism ; pathology ; therapy ; Gastrointestinal Stromal Tumors ; genetics ; metabolism ; pathology ; therapy ; Humans ; Imatinib Mesylate ; Indoles ; administration & dosage ; Membrane Proteins ; metabolism ; Neoplasm Proteins ; metabolism ; Piperazines ; administration & dosage ; Proto-Oncogene Proteins c-kit ; metabolism ; Pyrimidines ; administration & dosage ; Pyrroles ; administration & dosage ; Receptor, Platelet-Derived Growth Factor alpha ; genetics ; metabolism ; Vascular Endothelial Growth Factor A ; metabolism

OBJECTIVETo explore the effect of malignant transformation of the L839P, a new mutation site of the PDGFRA gene, on the pathogenesis of gastrointestinal stromal tumors.

METHODSAll recombinant plasmids were stably transfected into CHO cells by liposomes. Western blotting was used to detect the expression of PDGFRA protein. The cell growth curve was plotted by cell counting. Flow cytometry was used to detect the cell cycle and apoptosis of CHO cell, respectively. The stably transformed cells were inoculated subcutaneously into the back of nude mice and the mice were used to observe the tumorigenesis. Transient transfection of the mutant-type plasmids of PDGFRA gene and the wild-type plasmids of kit gene into the CHO cells was performed. Western blot was used to detect the expression of kit protein and its phosphorylated forms.

RESULTSPDGFRA protein expressed in the negative control, experimental group and positive control, except the empty vector. The growth curve showed that it was accelerated in the experimental group and positive control. The ratios of cells in proliferative phase were 28.4% (blank), 24.5% (negative control), 43.8% (experimental group) and 40.9% (positive control). Their apoptotic indexes were 1.8%, 1.9%, 1.5% and 1.6%, respectively. After three weeks, tumors were observed in the nude mice of experimental group and positive control, inoculated with the stably transformed cells. Moreover, the expression of phosphorylated protein of kit was enhanced after cotransfection of the mutant-type plasmids of PDGFRA and the wild-type plasmid of kit.

CONCLUSIONThe PDGFRA mutant L839P is a gain-of-function mutation and has obviously malignant transforming effect on normal cells, and may activate kit protein accelerating the tumorigenesis. Gastrointestinal stromal tumors;

Animals ; Apoptosis ; CHO Cells ; Cell Cycle ; Cell Proliferation ; Cell Transformation, Neoplastic ; Cricetinae ; Cricetulus ; Gastrointestinal Stromal Tumors ; etiology ; genetics ; pathology ; Mice ; Mice, Nude ; Mutation ; Plasmids ; Proto-Oncogene Proteins c-kit ; metabolism ; Receptor, Platelet-Derived Growth Factor alpha ; genetics ; metabolism ; Transfection