PURPOSE: Rearrangement of the proto-oncogene rearranged during transfection (RET) has been newly identified potential driver mutation in lung adenocarcinoma. Clinically available tyrosine kinase inhibitors (TKIs) target RET kinase activity, which suggests that patients with RET fusion genes may be treatable with a kinase inhibitor. Nevertheless, the mechanisms of resistance to these agents remain largely unknown. Thus, the present study aimed to determine whether epidermal growth factor (EGF) and hepatocyte growth factor (HGF) trigger RET inhibitor resistance in LC-2/ad cells with CCDC6-RET fusion genes. MATERIALS AND METHODS: The effects of EGF and HGF on the susceptibility of a CCDC6-RET lung cancer cell line to RET inhibitors (sunitinib, E7080, vandetanib, and sorafenib) were examined. RESULTS: CCDC6-RET lung cancer cells were highly sensitive to RET inhibitors. EGF activated epidermal growth factor receptor (EGFR) and triggered resistance to sunitinib, E7080, vandetanib, and sorafenib by transducing bypass survival signaling through ERK and AKT. Reversible EGFR-TKI (gefitinib) resensitized cancer cells to RET inhibitors, even in the presence of EGF. Endothelial cells, which are known to produce EGF, decreased the sensitivity of CCDC6-RET lung cancer cells to RET inhibitors, an effect that was inhibited by EGFR small interfering RNA (siRNA), anti-EGFR antibody (cetuximab), and EGFR-TKI (Iressa). HGF had relatively little effect on the sensitivity to RET inhibitors. CONCLUSION: EGF could trigger resistance to RET inhibition in CCDC6-RET lung cancer cells, and endothelial cells may confer resistance to RET inhibitors by EGF. E7080 and other RET inhibitors may provide therapeutic benefits in the treatment of RET-positive lung cancer patients.
Adenocarcinoma/drug therapy/*genetics ; Cell Line, Tumor ; Cetuximab/pharmacology ; Drug Resistance, Neoplasm/drug effects/*genetics ; Epidermal Growth Factor/metabolism/*pharmacology ; *Gene Rearrangement ; Hepatocyte Growth Factor/*pharmacology ; Humans ; Indoles/pharmacology ; Lung Neoplasms/drug therapy/*genetics ; MAP Kinase Signaling System ; *Mutation ; Niacinamide/analogs & derivatives/pharmacology ; Phenylurea Compounds/pharmacology ; Piperidines/pharmacology ; Protein Kinase Inhibitors/therapeutic use ; Proto-Oncogene Proteins c-ret/*antagonists & inhibitors/genetics ; Pyrroles/pharmacology ; Quinazolines/pharmacology ; RNA, Small Interfering/pharmacology ; Receptor, Epidermal Growth Factor/genetics/metabolism ; Signal Transduction/drug effects ; fms-Like Tyrosine Kinase 3/metabolism

No abstract available.
Aged ; Base Sequence ; Bone Marrow/metabolism/pathology ; DNA Mutational Analysis ; Female ; Fusion Proteins, bcr-abl/*genetics ; Gene Duplication ; Humans ; In Situ Hybridization, Fluorescence ; Leukemia, Myeloid, Acute/diagnosis/*genetics ; Multiplex Polymerase Chain Reaction ; Mutation ; Nuclear Proteins/*genetics ; Philadelphia Chromosome ; fms-Like Tyrosine Kinase 3/*genetics

BACKGROUND: Nucleophosmin gene (NPM1) mutation may be a good molecular marker for assessing the clinical status and predicting the outcomes in AML patients. We evaluated the applicability of NPM1 type A mutation (NPM1-mutA) quantitation for this purpose. METHODS: Twenty-seven AML patients with normal karyotype but bearing the mutated NPM1 were enrolled in the study, and real-time quantitative PCR of NPM1-mutA was performed on 93 bone marrow (BM) samples (27 samples at diagnosis and 56 at follow-up). The NPM1-mutA allele burdens (represented as the NPM1-mutA/Abelson gene (ABL) ratio) at diagnosis and at follow-up were compared. RESULTS: The median NPM1-mutA/ABL ratio was 1.3287 at diagnosis and 0.092 at 28 days after chemotherapy, corresponding to a median log10 reduction of 1.7061. Significant correlations were observed between BM blast counts and NPM1-mutA quantitation results measured at diagnosis (γ=0.5885, P=0.0012) and after chemotherapy (γ=0.5106, P=0.0065). Total 16 patients achieved morphologic complete remission at 28 days after chemotherapy, and 14 (87.5%) patients showed a >3 log10 reduction of the NPM1-mutA/ABL ratio. The NPM1-mutA allele was detected in each of five patients who had relapsed, giving a median increase of 0.91-fold of the NPM1-mutA/ABL ratio at relapse over that at diagnosis. CONCLUSIONS: The NPM1-mutA quantitation results corresponded to BM assessment results with high stability at relapse, and could predict patient outcomes. Quantitation of the NPM1-mutA burden at follow-up would be useful in the management of AML patients harboring this gene mutation.
Antineoplastic Agents/therapeutic use ; Bone Marrow/metabolism/pathology ; Cytarabine/therapeutic use ; Daunorubicin ; Humans ; Karyotype ; Leukemia, Myeloid, Acute/drug therapy/genetics/*pathology ; Mutation ; Nuclear Proteins/*genetics/metabolism ; Real-Time Polymerase Chain Reaction ; Recurrence ; Remission Induction ; Retrospective Studies ; Sequence Analysis, DNA ; fms-Like Tyrosine Kinase 3/genetics

No abstract available.
Adolescent ; Child ; Flow Cytometry ; Gene Rearrangement ; Humans ; Immunophenotyping ; Karyotyping ; Male ; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma/*diagnosis ; Receptors, Antigen, T-Cell/genetics/metabolism ; fms-Like Tyrosine Kinase 3/genetics

OBJECTIVETo study the efficacy and safety of sorafenib combined with low dose cytarabine for treating patients with FLT3(+) relapsed and refractory acute myeloid leukemia (FLT3(+) RR-AML).

METHODSSeven patients with FLT3(+) RR-AML were treated with sorafenib and low dose cytarabine. The curative rate and adverse effects were observed in these patients.

RESULTSOut of 7 RR-AML patients after treatment, 5 patients achieved complete remission (CR), 2 patients achieved partial remission (PR), and the overall response rate (ORR) after one course of therapy was 100%. No severe bleeding, nausea, vomiting and other side effects were found in these patients.

CONCLUSIONSorafenib combined with low dose cytarabine can effectively induce the remission of FLT3(+) RR-AML patients, and is worth for further clinical trails to verify its safty and efficiency.

Cytarabine ; therapeutic use ; Humans ; Leukemia, Myeloid, Acute ; drug therapy ; Niacinamide ; analogs & derivatives ; therapeutic use ; Phenylurea Compounds ; therapeutic use ; Recurrence ; Remission Induction ; Treatment Outcome ; fms-Like Tyrosine Kinase 3 ; metabolism

Humans ; Leukemia, Myeloid, Acute ; drug therapy ; Molecular Targeted Therapy ; fms-Like Tyrosine Kinase 3 ; metabolism

BACKGROUND: N-ras mutations are one of the most commonly detected abnormalities of myeloid origin. N-ras mutations result in a constitutively active N-ras protein that induces uncontrolled cell proliferation and inhibits apoptosis. We analyzed N-ras mutations in adult patients with AML at a particular institution and compared pyrosequencing analysis with a direct sequencing method for the detection of N-ras mutations. METHODS: We analyzed 90 bone marrow samples from 83 AML patients. We detected N-ras mutations in codons 12, 13, and 61 using the pyrosequencing method and subsequently confirmed all data by direct sequencing. Using these methods, we screened the N-ras mutation quantitatively and determined the incidence and characteristic of N-ras mutation. RESULTS: The incidence of N-ras mutation was 7.2% in adult AML patients. The patients with N-ras mutations showed significant higher hemoglobin levels (P=0.022) and an increased incidence of FLT3 mutations (P=0.003). We observed 3 cases with N-ras mutations in codon 12 (3.6%), 2 cases in codon 13 (2.4%), and 1 case in codon 61 (1.2%). All the mutations disappeared during chemotherapy. CONCLUSIONS: There is a low incidence (7.2%) of N-ras mutations in AML patients compared with other populations. Similar data is obtained by both pyrosequencing and direct sequencing. This study showed the correlation between the N-ras mutation and the therapeutic response. However, pyrosequencing provides quantitative data and is useful for monitoring therapeutic responses.
Adult ; Aged ; Aged, 80 and over ; Antineoplastic Agents/therapeutic use ; Bone Marrow/metabolism ; Codon ; Cytogenetic Analysis ; Female ; Hemoglobins/metabolism ; Humans ; Incidence ; Leukemia, Myeloid, Acute/drug therapy/epidemiology/*genetics ; Male ; Middle Aged ; Mutation ; Sequence Analysis, DNA ; fms-Like Tyrosine Kinase 3/genetics ; ras Proteins/*genetics

BACKGROUND: N-ras mutations are one of the most commonly detected abnormalities of myeloid origin. N-ras mutations result in a constitutively active N-ras protein that induces uncontrolled cell proliferation and inhibits apoptosis. We analyzed N-ras mutations in adult patients with AML at a particular institution and compared pyrosequencing analysis with a direct sequencing method for the detection of N-ras mutations. METHODS: We analyzed 90 bone marrow samples from 83 AML patients. We detected N-ras mutations in codons 12, 13, and 61 using the pyrosequencing method and subsequently confirmed all data by direct sequencing. Using these methods, we screened the N-ras mutation quantitatively and determined the incidence and characteristic of N-ras mutation. RESULTS: The incidence of N-ras mutation was 7.2% in adult AML patients. The patients with N-ras mutations showed significant higher hemoglobin levels (P=0.022) and an increased incidence of FLT3 mutations (P=0.003). We observed 3 cases with N-ras mutations in codon 12 (3.6%), 2 cases in codon 13 (2.4%), and 1 case in codon 61 (1.2%). All the mutations disappeared during chemotherapy. CONCLUSIONS: There is a low incidence (7.2%) of N-ras mutations in AML patients compared with other populations. Similar data is obtained by both pyrosequencing and direct sequencing. This study showed the correlation between the N-ras mutation and the therapeutic response. However, pyrosequencing provides quantitative data and is useful for monitoring therapeutic responses.
Adult ; Aged ; Aged, 80 and over ; Antineoplastic Agents/therapeutic use ; Bone Marrow/metabolism ; Codon ; Cytogenetic Analysis ; Female ; Hemoglobins/metabolism ; Humans ; Incidence ; Leukemia, Myeloid, Acute/drug therapy/epidemiology/*genetics ; Male ; Middle Aged ; Mutation ; Sequence Analysis, DNA ; fms-Like Tyrosine Kinase 3/genetics ; ras Proteins/*genetics

The purpose of this study was to investigate the effects of Celecoxib on the proliferation of the FLT3-ITD positive and negative acute myeloid leukemia cells and its mechanism. The proliferation inhibition effect of Celecoxib with different doses on the FLT3-ITD positive cells MV4-11 and the FLT3-ITD negative K562 cells was detected by CCK-8 method, the cell apoptosis was determined by flow cytometry, and the MEK, Mcl-1, pAKT expression was tested by Western blot. The results showed that Celecoxib inhibited the proliferation of both MV4-11 and K562 cells, but the IC50 for MV4-11 was (29.14 ± 2.4) µmol/L, which was significantly lower than that of K562 cells (39.84 ± 1.0) µmol/L (P < 0.05); The induced apoptosis rate of Celecoxib at 20-80 µmol/L on MV4-11 was not observed, but there was apparent influence on K562 at the same concentration. Western blot showed that Celecoxib down-regulated the expression of MEK and Mcl-1 but did not change the expression of pAKT obviously on MV4-11 cells, while the expression of Mcl-1 was reduced a little, but no obvious change were found in the expression of MEK and pAKT on K562 cells. It is concluded that the Celecoxib can inhibit the proliferation of FLT3-ITD positive AML cells distinctly, and the potential mechanism may be related to the inhibition of the MEK/Mcl-1 signaling pathway.
Apoptosis ; drug effects ; Celecoxib ; Cell Proliferation ; drug effects ; Cyclooxygenase 2 Inhibitors ; pharmacology ; Gene Expression Regulation, Leukemic ; Humans ; K562 Cells ; Leukemia, Myeloid, Acute ; drug therapy ; metabolism ; pathology ; MAP Kinase Kinase 1 ; genetics ; Myeloid Cell Leukemia Sequence 1 Protein ; genetics ; Proto-Oncogene Proteins c-akt ; genetics ; Pyrazoles ; pharmacology ; Signal Transduction ; Sulfonamides ; pharmacology ; fms-Like Tyrosine Kinase 3 ; genetics

Objective of this study was to detect the expression of Survivin in acute myeloid leukemia (AML) and investigate the relationship of its expression levels with clinical variates and its correlations with BCL-2 ,Bcl-xL and MCL-1. The expression of Survivin, BCL-2, Bcl-xL and MCL-1 were measured by immunohistochemistry in bone marrow biopsy of 63 newly diagnosed AML patients, and the relationship between its expression level and clinical parameters (age, sex, WBC count, diagnosis, prognosis), especially fusion protein AML1/ETO was investigated. The results showed that the expression level of Survivin in newly diagnosed AML patients was higher than that of normal controls (P < 0.01), the expression levels of Survivin did not correlate with age, sex, and WBC counts of patients and so on. There was no significant difference of Survivin expression between different NCCN prognosis groups, either between patients with AML1/ETO or FLT3-ITD mutation and the other patients. Survivin positive patients were got to have lower CR rate but higher relapse rate, however that was not significant in statistics. Indeed, the cumulative survivin rate of Survivin positive patients were lower than that of Survivin negative patients (P = 0.04). Finally, positive correlation between Survivin and MCL-1 was also observed (r = 0.639, P = 0.000). It is concluded that overexpression of Survivin are closely related with occurrence and development of acute leukemia, and may be used as an indicator of prognosis evaluation. In addition, Survivin and MCL-1 may have a relationship of cooperation or interaction.
Adolescent ; Adult ; Core Binding Factor Alpha 2 Subunit ; metabolism ; Female ; Humans ; Inhibitor of Apoptosis Proteins ; metabolism ; Leukemia, Myeloid, Acute ; metabolism ; pathology ; Male ; Middle Aged ; Mutation ; Myeloid Cell Leukemia Sequence 1 Protein ; metabolism ; Oncogene Proteins, Fusion ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; RUNX1 Translocation Partner 1 Protein ; Young Adult ; bcl-X Protein ; metabolism ; fms-Like Tyrosine Kinase 3 ; metabolism