Objective: This study was designed to explore whether inhibition of the extracellular-regulated kinase (ERK) and phosphatidylinositol-3-kinase (PI3K) signaling pathways can inhibit the growth of xenografts of endometr...Objective: This study was designed to explore whether inhibition of the extracellular-regulated kinase (ERK) and phosphatidylinositol-3-kinase (PI3K) signaling pathways can inhibit the growth of xenografts of endometrial cancer cell lines with different estrogen receptors (ER) profiles in vivo and to provide preliminary laboratory basis for the probability of endometrial adenocarcinoma treatment with blockage of the two pathways, especially to endometrial cancer with low ER status. Methods: Human endometrial cancer Ishikawa bearing ER and HEC-1Awith low ER status cells were subcutaneously injected into BALB/c nude mice to establish endometrial cancer xenograft tumor models. The effects of PI3K/Akt inhibitor LY294002, MAPK/ERK1/2 inhibitor PD-98059 and their combinations on the growth of the xenograft tumors and apoptotic state of Ishikawa and HEC-1Acells were tested in vivo using the inhibitory rate, the terminal deoxynucleotidyl transferase-mediated nick-end labeling assay, H/E-stain. Western blot analysis was used to detect the alterations of activated ERK (P-ERK) and AKT (P-AKT) during this process. Results: LY294002, a PI3K/Akt pathway inhibitor, induced significant suppression in the growth of both Ishikawa and HEC-1Acell xenograft tumors, concomitant with increased apoptosis in xenografts as evidenced by TUNEL. A similar effect was also observed when the MAPK/ERK1/2 signaling pathway was inhibited by PD98059. Concurrent inhibition of the PI3K/Akt and MAPK/ERK1/2 pathways showed enhanced anti-tumor effects in vivo as indicated by increased apoptosis. At the same time, the levels of P-ERK and P-AKT in both xenograft tumors decreased, and their levels in combination group was the lowest. Conclusions: PD98059, LY294002 and their combinations showed remarkable inhibitory effects on xenograft tumors of endometrial carcinoma cell lines with different expression status of ER in vivo through blockage of PI3K/Akt and MAPK/ERK1/2 signaling pathways. This suggests that targeting these pathways may be an effective therapeutic strategy against endometrial carcinomas, especially for ER-negative cancers which show poor response to endocrinal therapy.展开更多
Receptor Tyrosine kinases (RTKs) play a crucial role in the signal transduction pathways at cellular levels. RTK plays a vital role in cellular communication and transmission of signals to the adjacent cells and regul...Receptor Tyrosine kinases (RTKs) play a crucial role in the signal transduction pathways at cellular levels. RTK plays a vital role in cellular communication and transmission of signals to the adjacent cells and regulates different functions of the cell, such as cellular growth, differentiation, metabolism and motility. RTK s triggers growth factor receptors such as epidermal growth factor, insulin growth factor-1 receptor, platelet derived growth factor receptor, and fibro blast growth factor receptor and vascular endothelial growth factor receptor, thereby initiating and regulating cell growth and proliferation. MAPK/RAS and PI3/AKT pathways are the major pathways of RTK’s function. Dysregulation of these RTK’s and pathways often leads to many diseases such as Noonan Syndrome, Logius Syndrome, CFC syndrome and different types of cancer. Point mutation and over expression of receptors and mutations in Ras leads to 30% of human cancers. Also over expression of different growth factor receptors by RTK too lead to several types of cancers as Glioblastoma, Thyroid cancer, Colon cancer and Non-small cell lung cancer. PTEN mutation in PI3/AKT pathway often leads to carcinoma relative to Thyroid, Skin, Large intestine, eye and Bone. Therefore, these RTK’s often used as targets for cancer therapies. The medical sector uses various types of small molecule tyrosine kinase inhibitors such as ATP competitive inhibitors, Allosteric inhibitors and covalent inhibitors which are known as Afatinib, Crizotinib, Eroltinib, Icotinib, Lepatinib and Lenvatinib in treatment and management of differential carcinomas.展开更多
Delay of axon regeneration after peripheral nerve injury usually leads to progressive muscle atrophy and poor functional recovery. The Wnt/β-catenin signaling pathway is considered to be one of the main molecular mec...Delay of axon regeneration after peripheral nerve injury usually leads to progressive muscle atrophy and poor functional recovery. The Wnt/β-catenin signaling pathway is considered to be one of the main molecular mechanisms that lead to skeletal muscle atrophy in the elderly. We hold the hypothesis that the innervation of target muscle can be promoted by accelerating axon regeneration and decelerating muscle cell degeneration so as to improve functional recovery of skeletal muscle following peripheral nerve injury. This process may be associated with the Wnt/β-catenin signaling pathway. Our study designed in vitro cell models to simulate myelin regeneration and muscle atrophy. We investigated the effects of SB216763, a glycogen synthase kinase 3 beta inhibitor, on the two major murine cell lines RSC96 and C2C12 derived from Schwann cells and muscle satellite cells. The results showed that SB216763 stimulated the Schwann cell migra- tion and myotube contraction. Quantitative polymerase chain reaction results demonstrated that myelin related genes, myelin associated glycoprotein and cyclin-D1, muscle related gene myogenin and endplate-associated gene nicotinic acetylcholine receptors levels were stimulated by SB216763. Immunocytochemical staining revealed that the expressions of ^-catenin in the RSC96 and C2C12 cytosolic and nuclear compartments were increased in the SB216763-treated cells. These findings confirm that the glycogen synthase kinase 3 beta in- hibitor, SB216763, promoted the myelination and myotube differentiation through the Wnt/β-catenin signaling pathway and contributed to nerve remyelination and reduced denervated muscle atrophy after peripheral nerve injury.展开更多
FMS-like tyrosine kinase 3(FLT3) is classified as a type Ⅲ receptor tyrosine kinase, which exerts a key role in regulation of normal hematopoiesis. FLT3 mutation is the most common genetic mutation in acute myeloid l...FMS-like tyrosine kinase 3(FLT3) is classified as a type Ⅲ receptor tyrosine kinase, which exerts a key role in regulation of normal hematopoiesis. FLT3 mutation is the most common genetic mutation in acute myeloid leukemia(AML) and represents an attractive therapeutic target. Targeted therapy with FLT3 inhibitors in AML shows modest promising results in current ongoing clinical trials suggesting the complexity of FLT3 targeting in therapeutics. Importantly, resistance to FLT3 inhibitors may explain the lack of overwhelming response and could obstruct the successful treatment for AML. Here, we summarize the molecular mechanisms of primary resistance and acquired resistance to FLT3 inhibitors and discuss the strategies to circumvent the emergency of drug resistance and to develop novel treatment intervention.展开更多
A series of 2,4,5-triaryl substituted 1H-pyrazol-3（2H）-ones,as ALK5 inhibitors,were desigened,synthesized and evaluated in vitro.Most compounds exhibited noticeable ALK5 inhibition activities at 1μmol/L and display...A series of 2,4,5-triaryl substituted 1H-pyrazol-3（2H）-ones,as ALK5 inhibitors,were desigened,synthesized and evaluated in vitro.Most compounds exhibited noticeable ALK5 inhibition activities at 1μmol/L and displayed no significant cytotoxicities at 30μmol/L.展开更多
Axonal growth inhibitors are released during traumatic injuries to the adult mammalian central nervous system, including after spinal cord injury. These molecules accumulate at the injury site and form a highly inhibi...Axonal growth inhibitors are released during traumatic injuries to the adult mammalian central nervous system, including after spinal cord injury. These molecules accumulate at the injury site and form a highly inhibitory environment for axonal regeneration. Among these inhibitory molecules, myelinassociated inhibitors, including neurite outgrowth inhibitor A, oligodendrocyte myelin glycoprotein, myelin-associated glycoprotein, chondroitin sulfate proteoglycans and repulsive guidance molecule A are of particular importance. Due to their inhibitory nature, they represent exciting molecular targets to study axonal inhibition and regeneration after central injuries. These molecules are mainly produced by neurons, oligodendrocytes, and astrocytes within the scar and in its immediate vicinity. They exert their effects by binding to specific receptors, localized in the membranes of neurons. Receptors for these inhibitory cues include Nogo receptor 1, leucine-rich repeat, and Ig domain containing 1 and p75 neurotrophin receptor/tumor necrosis factor receptor superfamily member 19(that form a receptor complex that binds all myelin-associated inhibitors), and also paired immunoglobulin-like receptor B. Chondroitin sulfate proteoglycans and repulsive guidance molecule A bind to Nogo receptor 1, Nogo receptor 3, receptor protein tyrosine phosphatase σ and leucocyte common antigen related phosphatase, and neogenin, respectively. Once activated, these receptors initiate downstream signaling pathways, the most common amongst them being the Rho A/ROCK signaling pathway. These signaling cascades result in actin depolymerization, neurite outgrowth inhibition, and failure to regenerate after spinal cord injury. Currently, there are no approved pharmacological treatments to overcome spinal cord injuries other than physical rehabilitation and management of the array of symptoms brought on by spinal cord injuries. However, several novel therapies aiming to modulate these inhibitory proteins and/or their receptors are under investigation in ongoing clinical trials. Investigation has also been demonstrating that combinatorial therapies of growth inhibitors with other therapies, such as growth factors or stem-cell therapies, produce stronger results and their potential application in the clinics opens new venues in spinal cord injury treatment.展开更多
Human epidermal growth factor receptor 3(HER3)is a unique member of the human epidermal growth factor receptor(HER/EGFR)family,since it has negligible kinase activity.Therefore,HER3 must interact with a kinase-profici...Human epidermal growth factor receptor 3(HER3)is a unique member of the human epidermal growth factor receptor(HER/EGFR)family,since it has negligible kinase activity.Therefore,HER3 must interact with a kinase-proficient receptor to form a heterodimer,leading to the activation of signaling cascades.Overexpression of HER3 is observed in various human cancers,including non-small cell lung cancer(NSCLC),and correlates with poor clinical outcomes in patients.Studies on the underlying mechanism demonstrate that HER3-initiated signaling promotes tumor metastasis and causes treatment failure in human cancers.Upregulation of HER3 is frequently observed in EGFR-mutant NSCLC treated with EGFR-tyrosine kinase inhibitors(TKIs).Increased expression of HER3 triggers the so-called EGFR-independent mechanism via interactions with other receptors to activate“by-pass signaling pathways”,thereby resulting in resistance to EGFR-TKIs.To date,no HER3-targeted therapy has been approved for cancer treatment.In both preclinical and clinical studies,targeting HER3 with a blocking an-tibody(Ab)is the only strategy being examined.Recent evaluations of an anti-HER3 Ab-drug conjugate(ADC)show promising results in patients with EGFR-TKI-resistant NSCLC.Herein,we summarize our understanding of the unique biology of HER3 in NSCLC refractory to EGFR-TKIs,with a focus on its dimerization partners and subsequent activation of signaling pathways.We also discuss the latest development of the therapeutic Abs and ADCs targeting HER3 to abrogate EGFR-TKI resistance in NSCLC.展开更多
目的:探讨磷脂酰肌醇3激酶抑制剂LY294002对人胚胎干细胞定向分化为成熟胰岛素分泌细胞的影响。方法:体外通过5个阶段诱导人胚胎干细胞定向分化为胰岛素分泌细胞。分别给予尼克酰胺+B27(B27组)为对照组和尼克酰胺+LY294002(LY组)为实验...目的:探讨磷脂酰肌醇3激酶抑制剂LY294002对人胚胎干细胞定向分化为成熟胰岛素分泌细胞的影响。方法:体外通过5个阶段诱导人胚胎干细胞定向分化为胰岛素分泌细胞。分别给予尼克酰胺+B27(B27组)为对照组和尼克酰胺+LY294002(LY组)为实验组诱导胰岛素分泌细胞的成熟。显微镜下观察各阶段细胞形态变化,免疫荧光染色鉴定胰岛素、c-肽、生长抑素和胰高血糖素的表达。结果:第5阶段诱导14 d LY组胰岛素单染阳性率与B27组无统计学差别(P﹥0.05),但生长抑素和胰高血糖素单染阳性率,胰岛素/生长抑素共染率均低于B27组(P﹤0.05)。结论:在无血清培养体系下,磷脂酰肌醇3激酶抑制剂LY294002能够诱导人胚胎干细胞分化为更加成熟的胰岛素分泌细胞。展开更多
文摘Objective: This study was designed to explore whether inhibition of the extracellular-regulated kinase (ERK) and phosphatidylinositol-3-kinase (PI3K) signaling pathways can inhibit the growth of xenografts of endometrial cancer cell lines with different estrogen receptors (ER) profiles in vivo and to provide preliminary laboratory basis for the probability of endometrial adenocarcinoma treatment with blockage of the two pathways, especially to endometrial cancer with low ER status. Methods: Human endometrial cancer Ishikawa bearing ER and HEC-1Awith low ER status cells were subcutaneously injected into BALB/c nude mice to establish endometrial cancer xenograft tumor models. The effects of PI3K/Akt inhibitor LY294002, MAPK/ERK1/2 inhibitor PD-98059 and their combinations on the growth of the xenograft tumors and apoptotic state of Ishikawa and HEC-1Acells were tested in vivo using the inhibitory rate, the terminal deoxynucleotidyl transferase-mediated nick-end labeling assay, H/E-stain. Western blot analysis was used to detect the alterations of activated ERK (P-ERK) and AKT (P-AKT) during this process. Results: LY294002, a PI3K/Akt pathway inhibitor, induced significant suppression in the growth of both Ishikawa and HEC-1Acell xenograft tumors, concomitant with increased apoptosis in xenografts as evidenced by TUNEL. A similar effect was also observed when the MAPK/ERK1/2 signaling pathway was inhibited by PD98059. Concurrent inhibition of the PI3K/Akt and MAPK/ERK1/2 pathways showed enhanced anti-tumor effects in vivo as indicated by increased apoptosis. At the same time, the levels of P-ERK and P-AKT in both xenograft tumors decreased, and their levels in combination group was the lowest. Conclusions: PD98059, LY294002 and their combinations showed remarkable inhibitory effects on xenograft tumors of endometrial carcinoma cell lines with different expression status of ER in vivo through blockage of PI3K/Akt and MAPK/ERK1/2 signaling pathways. This suggests that targeting these pathways may be an effective therapeutic strategy against endometrial carcinomas, especially for ER-negative cancers which show poor response to endocrinal therapy.
文摘Receptor Tyrosine kinases (RTKs) play a crucial role in the signal transduction pathways at cellular levels. RTK plays a vital role in cellular communication and transmission of signals to the adjacent cells and regulates different functions of the cell, such as cellular growth, differentiation, metabolism and motility. RTK s triggers growth factor receptors such as epidermal growth factor, insulin growth factor-1 receptor, platelet derived growth factor receptor, and fibro blast growth factor receptor and vascular endothelial growth factor receptor, thereby initiating and regulating cell growth and proliferation. MAPK/RAS and PI3/AKT pathways are the major pathways of RTK’s function. Dysregulation of these RTK’s and pathways often leads to many diseases such as Noonan Syndrome, Logius Syndrome, CFC syndrome and different types of cancer. Point mutation and over expression of receptors and mutations in Ras leads to 30% of human cancers. Also over expression of different growth factor receptors by RTK too lead to several types of cancers as Glioblastoma, Thyroid cancer, Colon cancer and Non-small cell lung cancer. PTEN mutation in PI3/AKT pathway often leads to carcinoma relative to Thyroid, Skin, Large intestine, eye and Bone. Therefore, these RTK’s often used as targets for cancer therapies. The medical sector uses various types of small molecule tyrosine kinase inhibitors such as ATP competitive inhibitors, Allosteric inhibitors and covalent inhibitors which are known as Afatinib, Crizotinib, Eroltinib, Icotinib, Lepatinib and Lenvatinib in treatment and management of differential carcinomas.
基金funded by the National Basic Research Program of China(973 Program),No.2014CB542201the National High Technology Research and Development Program of China(863 Program),No.SS2015AA020501the National Natural Science Foundation of China(General Program),No.31571235,31771322,31671248,31571236,31271284,31171150,81171146,31471144,30971526,31100860,31040043,31371210,and 81372044
文摘Delay of axon regeneration after peripheral nerve injury usually leads to progressive muscle atrophy and poor functional recovery. The Wnt/β-catenin signaling pathway is considered to be one of the main molecular mechanisms that lead to skeletal muscle atrophy in the elderly. We hold the hypothesis that the innervation of target muscle can be promoted by accelerating axon regeneration and decelerating muscle cell degeneration so as to improve functional recovery of skeletal muscle following peripheral nerve injury. This process may be associated with the Wnt/β-catenin signaling pathway. Our study designed in vitro cell models to simulate myelin regeneration and muscle atrophy. We investigated the effects of SB216763, a glycogen synthase kinase 3 beta inhibitor, on the two major murine cell lines RSC96 and C2C12 derived from Schwann cells and muscle satellite cells. The results showed that SB216763 stimulated the Schwann cell migra- tion and myotube contraction. Quantitative polymerase chain reaction results demonstrated that myelin related genes, myelin associated glycoprotein and cyclin-D1, muscle related gene myogenin and endplate-associated gene nicotinic acetylcholine receptors levels were stimulated by SB216763. Immunocytochemical staining revealed that the expressions of ^-catenin in the RSC96 and C2C12 cytosolic and nuclear compartments were increased in the SB216763-treated cells. These findings confirm that the glycogen synthase kinase 3 beta in- hibitor, SB216763, promoted the myelination and myotube differentiation through the Wnt/β-catenin signaling pathway and contributed to nerve remyelination and reduced denervated muscle atrophy after peripheral nerve injury.
基金Supported by the Singapore National Research Foundation and the Ministry of Education under the Research Center of Excellence Program(to Chng WJ)NMRC Clinician-Scientist IRG Grant,No.CNIG11nov38(to Zhou J)+1 种基金supported by NMRC Clinician Scientist Investigator awardsupported by the RNA Biology Center at CSI Singapore,NUS,from funding by the Singapore Ministry of Education’s Tier 3 grants,No.MOE2014-T3-1-006
文摘FMS-like tyrosine kinase 3(FLT3) is classified as a type Ⅲ receptor tyrosine kinase, which exerts a key role in regulation of normal hematopoiesis. FLT3 mutation is the most common genetic mutation in acute myeloid leukemia(AML) and represents an attractive therapeutic target. Targeted therapy with FLT3 inhibitors in AML shows modest promising results in current ongoing clinical trials suggesting the complexity of FLT3 targeting in therapeutics. Importantly, resistance to FLT3 inhibitors may explain the lack of overwhelming response and could obstruct the successful treatment for AML. Here, we summarize the molecular mechanisms of primary resistance and acquired resistance to FLT3 inhibitors and discuss the strategies to circumvent the emergency of drug resistance and to develop novel treatment intervention.
文摘A series of 2,4,5-triaryl substituted 1H-pyrazol-3（2H）-ones,as ALK5 inhibitors,were desigened,synthesized and evaluated in vitro.Most compounds exhibited noticeable ALK5 inhibition activities at 1μmol/L and displayed no significant cytotoxicities at 30μmol/L.
基金a Ph D fellowship by FCT-Fundacao para a Ciência Tecnologia (SFRH/BD/135868/2018)(to SSC)。
文摘Axonal growth inhibitors are released during traumatic injuries to the adult mammalian central nervous system, including after spinal cord injury. These molecules accumulate at the injury site and form a highly inhibitory environment for axonal regeneration. Among these inhibitory molecules, myelinassociated inhibitors, including neurite outgrowth inhibitor A, oligodendrocyte myelin glycoprotein, myelin-associated glycoprotein, chondroitin sulfate proteoglycans and repulsive guidance molecule A are of particular importance. Due to their inhibitory nature, they represent exciting molecular targets to study axonal inhibition and regeneration after central injuries. These molecules are mainly produced by neurons, oligodendrocytes, and astrocytes within the scar and in its immediate vicinity. They exert their effects by binding to specific receptors, localized in the membranes of neurons. Receptors for these inhibitory cues include Nogo receptor 1, leucine-rich repeat, and Ig domain containing 1 and p75 neurotrophin receptor/tumor necrosis factor receptor superfamily member 19(that form a receptor complex that binds all myelin-associated inhibitors), and also paired immunoglobulin-like receptor B. Chondroitin sulfate proteoglycans and repulsive guidance molecule A bind to Nogo receptor 1, Nogo receptor 3, receptor protein tyrosine phosphatase σ and leucocyte common antigen related phosphatase, and neogenin, respectively. Once activated, these receptors initiate downstream signaling pathways, the most common amongst them being the Rho A/ROCK signaling pathway. These signaling cascades result in actin depolymerization, neurite outgrowth inhibition, and failure to regenerate after spinal cord injury. Currently, there are no approved pharmacological treatments to overcome spinal cord injuries other than physical rehabilitation and management of the array of symptoms brought on by spinal cord injuries. However, several novel therapies aiming to modulate these inhibitory proteins and/or their receptors are under investigation in ongoing clinical trials. Investigation has also been demonstrating that combinatorial therapies of growth inhibitors with other therapies, such as growth factors or stem-cell therapies, produce stronger results and their potential application in the clinics opens new venues in spinal cord injury treatment.
基金We are grateful to Dr.Shi-Yong Sun(Emory University School of Medicine and Winship Cancer Institute)for his critical reading of the manuscript.This work was supported in part by a translational research grant from METAvivor Research and Support Inc.and a start-up fund provided by the Stanley S.Scott Cancer Center at Louisiana State Uni-versity(LSU)Health Sciences Center(to BL).
文摘Human epidermal growth factor receptor 3(HER3)is a unique member of the human epidermal growth factor receptor(HER/EGFR)family,since it has negligible kinase activity.Therefore,HER3 must interact with a kinase-proficient receptor to form a heterodimer,leading to the activation of signaling cascades.Overexpression of HER3 is observed in various human cancers,including non-small cell lung cancer(NSCLC),and correlates with poor clinical outcomes in patients.Studies on the underlying mechanism demonstrate that HER3-initiated signaling promotes tumor metastasis and causes treatment failure in human cancers.Upregulation of HER3 is frequently observed in EGFR-mutant NSCLC treated with EGFR-tyrosine kinase inhibitors(TKIs).Increased expression of HER3 triggers the so-called EGFR-independent mechanism via interactions with other receptors to activate“by-pass signaling pathways”,thereby resulting in resistance to EGFR-TKIs.To date,no HER3-targeted therapy has been approved for cancer treatment.In both preclinical and clinical studies,targeting HER3 with a blocking an-tibody(Ab)is the only strategy being examined.Recent evaluations of an anti-HER3 Ab-drug conjugate(ADC)show promising results in patients with EGFR-TKI-resistant NSCLC.Herein,we summarize our understanding of the unique biology of HER3 in NSCLC refractory to EGFR-TKIs,with a focus on its dimerization partners and subsequent activation of signaling pathways.We also discuss the latest development of the therapeutic Abs and ADCs targeting HER3 to abrogate EGFR-TKI resistance in NSCLC.
文摘目的:探讨磷脂酰肌醇3激酶抑制剂LY294002对人胚胎干细胞定向分化为成熟胰岛素分泌细胞的影响。方法:体外通过5个阶段诱导人胚胎干细胞定向分化为胰岛素分泌细胞。分别给予尼克酰胺+B27(B27组)为对照组和尼克酰胺+LY294002(LY组)为实验组诱导胰岛素分泌细胞的成熟。显微镜下观察各阶段细胞形态变化,免疫荧光染色鉴定胰岛素、c-肽、生长抑素和胰高血糖素的表达。结果:第5阶段诱导14 d LY组胰岛素单染阳性率与B27组无统计学差别(P﹥0.05),但生长抑素和胰高血糖素单染阳性率,胰岛素/生长抑素共染率均低于B27组(P﹤0.05)。结论:在无血清培养体系下,磷脂酰肌醇3激酶抑制剂LY294002能够诱导人胚胎干细胞分化为更加成熟的胰岛素分泌细胞。
