AIMTo evaluate whether protein tyrosine phosphatase 1B (PTP1B) contributed to initiate human retinal pigment epithelium cells (A)-19 migration and investigate the signaling pathways involved in this process.METHODSARP...AIMTo evaluate whether protein tyrosine phosphatase 1B (PTP1B) contributed to initiate human retinal pigment epithelium cells (A)-19 migration and investigate the signaling pathways involved in this process.METHODSARPE-19 cells were cultured and treated with the siRNA-PTP1B. Expression of PTP1B was confirmed by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). AG1478 [a selective inhibitor of epidermal growth factor receptor (EGFR)] and PD98059 (a specific inhibitor of the activation of mitogen-activated protein kinase) were used to help to determine the PTP1B signaling mechanism. Western blot analysis verified expression of EGFR and extracellular signal-regulated kinase (ERK) in ARPE-19 cells. The effect of siRNA-PTP1B on cell differentiation was confirmed by immunostaining for α-smooth muscle actin (α-SMA) and qRT-PCR. Cell migration ability was analyzed by transwell chamber assay.RESULTSThe mRNA levels of PTP1B were reduced by siRNA-PTP1B as determined by qRT-PCR assay. SiRNA-PTP1B activated EGFR and ERK phosphorylation. α-SMA staining and qRT-PCR assay demonstrated that siRNA-PTP1B induced retinal pigment epithelium (RPE) cells to differentiate toward better contractility and motility. Transwell chamber assay proved that PTP1B inhibition improved migration activity of RPE cells. Treatment with AG1478 and PD98059 abolished siRNA-PTP1B-induced activation of EGFR and ERK, α-SMA expression and cell migration.CONCLUSIONPTP1B inhibition promoted myofibroblast differentiation and migration of ARPE-19 cells, and EGFR/ERK signaling pathway played important role in migration process.展开更多
Since in most tumors multiple signaling pathways are involved,many of the inhibitors in clinical development are designed to affect a wide range of targeted kinases.The most important tyrosine kinase families in the d...Since in most tumors multiple signaling pathways are involved,many of the inhibitors in clinical development are designed to affect a wide range of targeted kinases.The most important tyrosine kinase families in the development of tyrosine kinase inhibitors are the ABL,SCR,platelet derived growth factor,vascular endothelial growth factor receptor and epidermal growth factor receptor families.Both multi-kinase inhibitors and singlekinase inhibitors have advantages and disadvantages,which are related to potential resistance mechanisms,pharmacokinetics,selectivity and tumor environment.In different malignancies various tyrosine kinases are mutated or overexpressed and several resistance mechanisms exist.Pharmacokinetics is influenced by interindividual differences and differs for two single targeted inhibitors or between patients treated by the same tyrosine kinase inhibitor.Different tyrosine kinase inhibitors have various mechanisms to achieve selectivity,while differences in gene expression exist between tumor and stromal cells.Considering these aspects,one type of inhibitor can generally not be preferred above the other,but will depend on the specific genetic constitution of the patient and the tumor,allowing personalized therapy.The most effective way of cancer treatment by using tyrosine kinase inhibitors is to consider each patient/tumor individually and to determine the strategy that specifically targets the consequences of altered(epi)genetics of the tumor.This strategy might result in treatment by a single multi kinase inhibitor for one patient,but in treatment by a couple of single kinase inhibitors for other patients.展开更多
基金Supported by Shandong Provincial Natural Science Foundation,China(No.ZR2012HQ004)the Research Fund for Fundamental Research Project of Qingdao(No.13-1-4-180-jch)+1 种基金the Scientific Research Fund of Huangdao District of Qingdao City(No.2014-1-74)the Young People Scientific Research Fund of Affiliated Hospital,Qingdao University(No.QDFY134)
文摘AIMTo evaluate whether protein tyrosine phosphatase 1B (PTP1B) contributed to initiate human retinal pigment epithelium cells (A)-19 migration and investigate the signaling pathways involved in this process.METHODSARPE-19 cells were cultured and treated with the siRNA-PTP1B. Expression of PTP1B was confirmed by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). AG1478 [a selective inhibitor of epidermal growth factor receptor (EGFR)] and PD98059 (a specific inhibitor of the activation of mitogen-activated protein kinase) were used to help to determine the PTP1B signaling mechanism. Western blot analysis verified expression of EGFR and extracellular signal-regulated kinase (ERK) in ARPE-19 cells. The effect of siRNA-PTP1B on cell differentiation was confirmed by immunostaining for α-smooth muscle actin (α-SMA) and qRT-PCR. Cell migration ability was analyzed by transwell chamber assay.RESULTSThe mRNA levels of PTP1B were reduced by siRNA-PTP1B as determined by qRT-PCR assay. SiRNA-PTP1B activated EGFR and ERK phosphorylation. α-SMA staining and qRT-PCR assay demonstrated that siRNA-PTP1B induced retinal pigment epithelium (RPE) cells to differentiate toward better contractility and motility. Transwell chamber assay proved that PTP1B inhibition improved migration activity of RPE cells. Treatment with AG1478 and PD98059 abolished siRNA-PTP1B-induced activation of EGFR and ERK, α-SMA expression and cell migration.CONCLUSIONPTP1B inhibition promoted myofibroblast differentiation and migration of ARPE-19 cells, and EGFR/ERK signaling pathway played important role in migration process.
文摘Since in most tumors multiple signaling pathways are involved,many of the inhibitors in clinical development are designed to affect a wide range of targeted kinases.The most important tyrosine kinase families in the development of tyrosine kinase inhibitors are the ABL,SCR,platelet derived growth factor,vascular endothelial growth factor receptor and epidermal growth factor receptor families.Both multi-kinase inhibitors and singlekinase inhibitors have advantages and disadvantages,which are related to potential resistance mechanisms,pharmacokinetics,selectivity and tumor environment.In different malignancies various tyrosine kinases are mutated or overexpressed and several resistance mechanisms exist.Pharmacokinetics is influenced by interindividual differences and differs for two single targeted inhibitors or between patients treated by the same tyrosine kinase inhibitor.Different tyrosine kinase inhibitors have various mechanisms to achieve selectivity,while differences in gene expression exist between tumor and stromal cells.Considering these aspects,one type of inhibitor can generally not be preferred above the other,but will depend on the specific genetic constitution of the patient and the tumor,allowing personalized therapy.The most effective way of cancer treatment by using tyrosine kinase inhibitors is to consider each patient/tumor individually and to determine the strategy that specifically targets the consequences of altered(epi)genetics of the tumor.This strategy might result in treatment by a single multi kinase inhibitor for one patient,but in treatment by a couple of single kinase inhibitors for other patients.
