Intracellular signal transduction plays an important role in the process of cellular metabolism, segmentation, differentiation, biological behaviour and cell death. Overactive signal transduction relates to tumor development and progression. Signaling pathways operated by protein tyrosine kinases (PTKs) will be illuminated here briefly. The Ras/Raf/MAPK and PI-3K/Akt pathways through receptor protein tyrosine kinases (RTKs), the Src, Bcr-Abl and JAK/STAT pathways by non-receptor protein tyrosine kinases (nrPTKs) are shown separately. Antitumor agents targeting the key proteins involved in the above five signalling routes are also summarized in this review.
Animals ; Antineoplastic Agents ; pharmacology ; Humans ; Phosphatidylinositol 3-Kinases ; metabolism ; Protein-Tyrosine Kinases ; metabolism ; Receptor Protein-Tyrosine Kinases ; metabolism ; STAT Transcription Factors ; metabolism ; Signal Transduction ; drug effects ; ras Proteins ; metabolism ; src-Family Kinases ; metabolism

Adult ; Humans ; Lymphoma, Large B-Cell, Diffuse ; metabolism ; Male ; Receptor Protein-Tyrosine Kinases ; metabolism

As well as playing vital roles in main cellular processes, such as abnormal proliferation, differentiation, survival, apoptosis, and a lot of tyrosine kinases (TK) are involved in oncogenesis. TK or components of their signal pathways have been found abnormal in many hematological malignancies. Therefore, tyrosine kinase inhibitors (TKI) have been provided a great deal of enthusiasm for development of therapy in myeloproliferative neoplasms (MPN). Representativity, the treatment of chronic myelogenous leukemia (CML) was revolutionary for the design of imatinib mesylate (IM), which is a BCR/ABL TKI. Subsequently, because of need for the resistance or intolerance, novel agents are being explored and imatinib has now been extended to eosinophilia-associated myeloid neoplasms with PDGFRA, PDGFRB or FGFR1 gene mutations. Recently, JAK2 inhibitor drugs are currently being tested in clinical trials. Here, the current review mainly focuses on the role of TK in classic MPN including CML, polycythemia vera (PV), primary myelofibrosis (PMF), essential thrombocythemia (ET), and advances of targeting these abnormalities with small molecule inhibitors.
Drug Delivery Systems ; Humans ; Myeloproliferative Disorders ; drug therapy ; Protein-Tyrosine Kinases ; antagonists & inhibitors ; metabolism

Actins ; metabolism ; Adult ; Diagnosis, Differential ; Granzymes ; metabolism ; Histiocytic Sarcoma ; metabolism ; pathology ; Humans ; Ki-1 Antigen ; metabolism ; Lymph Nodes ; metabolism ; pathology ; Lymphoma, Large-Cell, Anaplastic ; metabolism ; pathology ; Male ; Neoplasms, Muscle Tissue ; metabolism ; pathology ; Protein-Tyrosine Kinases ; metabolism ; Receptor Protein-Tyrosine Kinases

OBJECTIVEFMS-like tyrosine kinase 3 (FLT3) is a receptor tyrosine kinase that is constitutively activated in (70-90)% pediatric patients with acute myeloid leukemia (AML) and appears to confer an adverse prognosis. Although several FLT3-selective small molecule inhibitors and antibodies were developed with varied degrees of success, to address the specificity and resistance, new approaches for specifically targeted FLT3 are needed and RNA interference is a promising choice. The aim of the present study was to investigate the efficacy of suppression of FLT3 induced by small hairpin interfering RNA (shRNA) on myeloproliferation and apoptosis in an acute monocytic leukemia (AMOL) cell line THP-1.

METHODSFLT3-targeted small hairpin interfering RNA (FLT3-shRNA) was designed and synthesized by transcription system in vitro was transfected into THP-1 cells. Firstly FLT3 mRNA level was detected by semi-quantitative RT-PCR and FLT3 protein level was detected by flow cytometry (FCM) to verify the efficacy on FLT3-shRNA interference at 48 h after transfection. Cell growth viability was measured at 24 h, 48 h and 72 h after treatment with CCK-8. The distribution of cell cycle was assayed by FCM, and apoptosis was analyzed by DNA Ladder and Annexin V-FITC Staining at 48 h.

RESULTSFLT3 targeted shRNAs was synthesized successfully and the concentration of 15 nmol/L for 48 h could obtain desirable downregulation of FLT3 expression, the inhibitory percentages of FLT3 mRNA and protein were (72.95 +/- 2.07)% and (65.39 +/- 5.57)%, respectively. The suppression of FLT3 induced by FLT3-shRNA resulted in marked inhibition of cell growth and the inhibitory percentages were (36.66 +/- 3.67)% at 48 h, (35.56 +/- 0.73)% at 72 h. FLT3-shRNA induced the inhibition of cell cycle from G(0)/G(1) phase to S phase, the percentage of sub-G(0)/G(1) phase (65.71 +/- 4.47)% was higher than those in the PBS-control group (52.23 +/- 2.98)%, NC-shRNA control group (51.81 +/- 1.44)%, P < 0.01; the percentage of S phase (25.11 +/- 2.70)% was lower than those in the PBS-control group (34.41 +/- 4.07)% and NC-shRNA control group (32.50 +/- 1.46)%, P < 0.05. Furthermore treatment with FLT3-shRNA for 48 h resulted in clear apoptosis ladder, the percentage of early apoptosis detected by Annexin V-FITC was (18.59 +/- 2.07)% which was significantly higher than that in the PBS-control group (4.00 +/- 0.50)% and the NC-shRNA control group (6.06 +/- 0.70)%, P < 0.001.

CONCLUSIONThe suppression of FLT3 induced by the shRNA can effectively inhibit cell proliferation, and apoptosis induction on THP-1 cells, which indicates that this approach may bear the therapeutic potential on childhood AMOL.

Apoptosis ; drug effects ; genetics ; Cell Proliferation ; drug effects ; Child ; Humans ; Leukemia, Monocytic, Acute ; enzymology ; pathology ; Protein-Tyrosine Kinases ; metabolism ; RNA Interference ; physiology ; RNA, Small Interfering ; pharmacology ; Receptor Protein-Tyrosine Kinases ; metabolism ; fms-Like Tyrosine Kinase 3 ; metabolism

OBJECTIVETo study the expression of anaplastic lymphoma kinase (ALK) and the phosphorylation status of AKT, mammalian target of rapamycin (mTOR), 4E-binding protein 1 (4E-BP1) and ribosomal protein S6 kinase (p70S6K) and their interrelationships and clinical pathological significance in anaplastic large cell lymphoma (ALCL) patients.

METHODSImmunohistochemical and EnVision methods were used to detect the expression of ALK, p-AKT, p-mTOR, p-4E-BP1 and p-p70S6K.

RESULTSAmong the 81 ALCL patients, 51 (63.0%) expressed ALK, whereas the other 30 (37.0%) did not. Patients with ALK(+) ALCL had a better prognosis than those with ALK-ALCL (P < 0.05). Out of the 71 ALCL samples studied, p-AKT was detected in 54 (76.1%) samples and its phosphorylation was correlated with ALK expression (P < 0.05); p-mTOR was detected in 57 (80.3%) samples and its expression was correlated with both ALK and p-AKT (P < 0.05); p-4E-BP1 and p-p70S6K were detected in 64 (90.1%) and 66 (93.0%) samples respectively, and their expressions were related with p-mTOR (P < 0.05), but not with ALK or p-AKT (P > 0.05). COX Proportional Hazard Model analysis showed that both the expression of ALK and the B symptoms affected the prognosis (P < 0.05), moreover, the former had greater impact than the later.

CONCLUSIONExpressions of p-AKT, p-mTOR, p-4E-BP1 and p-p70S6K are detected in ALCL, while ALK(+) cases have higher incidence than those with ALK(-) cases. Phosphorylation of AKT and mTOR is correlated with ALK expression, suggesting that there is an activated pathway of AKT/mTOR in patients with ALK(+) ALCL, but the activation have no obvious prognostic significance.

Adaptor Proteins, Signal Transducing ; metabolism ; Adolescent ; Adult ; Aged ; Child ; Child, Preschool ; Female ; Humans ; Intracellular Signaling Peptides and Proteins ; metabolism ; Lymphoma, Large-Cell, Anaplastic ; metabolism ; Male ; Middle Aged ; Phosphoproteins ; metabolism ; Phosphorylation ; Protein-Serine-Threonine Kinases ; metabolism ; Protein-Tyrosine Kinases ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; Receptor Protein-Tyrosine Kinases ; Ribosomal Protein S6 Kinases, 70-kDa ; metabolism ; Signal Transduction ; TOR Serine-Threonine Kinases ; Young Adult

Escherichia coli ; enzymology ; Fluorine Radioisotopes ; analysis ; Lipid Bilayers ; chemistry ; Magnetic Resonance Spectroscopy ; Maleates ; chemistry ; Nanoparticles ; chemistry ; Phosphorylation ; Polystyrenes ; chemistry ; Protein Conformation ; Protein-Tyrosine Kinases ; chemistry ; metabolism ; Tyrosine ; metabolism

Carcinoma, Non-Small-Cell Lung ; diagnosis ; metabolism ; therapy ; Humans ; Lung Neoplasms ; diagnosis ; metabolism ; therapy ; Receptor Protein-Tyrosine Kinases ; metabolism

OBJECTIVETo explore ALK protein expression and gene fusion in formalin-fixed and paraffin-embedded (FFPE) specimens obtained from lung cancer by bronchoscopy, and to investigate the relationship between ALK status and clinicopathological characteristics of the patients.

METHODSSeventy-four FFPE samples obtained from lung adenocarcinoma by bronchoscopy were tested for ALK protein expression and gene fusion respectively by immunohistochemistry (IHC) using Ventana D5F3 antibody and fluorescence in situ hybridization (FISH) using ALK break apart probe.

RESULTSsixty-five of the 74 samples were successfully tested by FISH (87.8%, 65/74) . There were 5 FISH-positive cases (7.7%, 5/65) , all with advanced stage carcinoma. Among these five FISH-positive cases, 3 were IHC-positive (4.1%, 3/74) and 2 IHC-negative cases. All the other 69 samples were IHC-negative, including nine FISH-uninformative samples (7 samples were less than 50 tumor cells and 2 samples with weak FISH signal). Both ALK IHC and FISH results were not correlated with age, sex, history of smoking, histological classification, differentiation and lymph node metastasis.

CONCLUSIONSBronchoscopic specimens of lung cancer can be used to detect ALK expression and gene fusion. Immunohistochemistry in combination with FISH test may be more favorable for ALK test.

Adenocarcinoma ; metabolism ; Gene Fusion ; Humans ; Immunohistochemistry ; In Situ Hybridization, Fluorescence ; Lung Neoplasms ; metabolism ; Receptor Protein-Tyrosine Kinases ; metabolism

OBJECTIVETo detect the expressions of receptor tyrosine kinases (RTKs) mRNA and protein and to explore potentially promising tumor markers and conceivable drug target in bladder cancer.

METHODSThe expressions of RTKs mRNA and protein in tissue from invasive urothelial carcinoma of the bladder were examined by real-time quantitative PCR array and cytokine antibody array, with normal bladder tissue as control. The Results were analyzed using bioinformatic approaches.

RESULTSThe expressions of TGFA, STAB1, SERPINE1, ANGPT2, SPINK5, ANGPTL1, PROK1, MDK, CXCL9, GRN, RUNX1, VEGFA, and TGFB1 were obviously upregulated in bladder cancer tissue, while those of EDIL3, PTN, CCL2, PDGFD, FGF13, KITLG, FGF2, SERPINF1, and TNF were downregulated. ALK, Btk, EphB2, ErbB4, PDGFR-α, ROS, Tie-2, Tyk2, and VEGFR3 were over-expressed in bladder cancer, while FRK, Fyn, IGF-IR, Insulin R, Itk, JAK1, JAK3, and LCK were low-expressed.

CONCLUSIONVascular endothelial growth factor/platelet-derived growth factor-targeted therapies may play an active role in treating carcinoma of bladder.

Carcinoma, Transitional Cell ; metabolism ; Humans ; RNA, Messenger ; genetics ; Receptor Protein-Tyrosine Kinases ; genetics ; metabolism ; Urinary Bladder Neoplasms ; metabolism