BACKGROUND Less than 0.5%of intravenously injected drugs reach tumors,contributing to side effects.To limit damage to healthy cells,various delivery vectors have been formulated;yet,previously developed vectors suffer...BACKGROUND Less than 0.5%of intravenously injected drugs reach tumors,contributing to side effects.To limit damage to healthy cells,various delivery vectors have been formulated;yet,previously developed vectors suffer from poor penetration into solid tumors.This issue was resolved by the discovery of HN-1 peptide isolated via biopanning a phage-display library.HN-1 targets human head and neck squamous cell carcinoma(HNSCC)(breast,thyroid;potentially lung,cervix,uterine,colon cancer),translocates across the cell membrane,and efficiently infiltrates solid tumors.HN-1 peptide has been conjugated to various anticancer drugs and imaging agents though the identity of its receptor remained enigmatic.AIM To decipher the clues that pointed to retinoblastoma(Rb)-regulated discoidindomain receptor 1 as the putative receptor for HN-1 is described.METHODS HN-1 peptide was synthesized and purified using reverse-phase highperformance liquid chromatography and gel electrophoresis.The predicted mass was confirmed by mass spectroscopy.To image the 3-dimensional structure of HN-1 peptide,PyMOL was used.Molecular modeling was also performed with PEP-FOLD3 software via RPBS bioinformatics web portal(INSERM,France).The immunohistochemistry results of discoidin domain receptor 1(DDR1)protein were obtained from the publicly accessible database in the Human Protein Atlas portal,which contained the images of immunohistochemically labeled human cancers and the corresponding normal tissues.RESULTS The clues that led to DDR1 involved in metastasis as the putative receptor mediating HN-1 endocytosis are the following:(1)HN-1 is internalized in phosphate-buffered saline and its uptake is competitively inhibited;(2)HN-1(TSPLNIHNGQKL)exhibits similarity with a stretch of amino acids in alpha5 beta3 integrin(KLLITIHDRKEF).Aside from two identical residues(Ile-His)in the middle,the overall distribution of polar and nonpolar residues throughout the sequences is nearly identical.As HN-1 sequence lacks the Arg-Gly-Asp motif recognized by integrins,HN-1 may interact with an"integrin-like"molecule.The tertiary structure of both peptides showed similarity at the 3-dimensional level;(3)HN-1 is internalized by attached cells but not by suspended cells.As culture plates are typically coated with collagen,collagen-binding receptor(expressed by adherent but not suspended cells)may represent the receptor for HN-1;(4)DDR1 is highly expressed in head and neck cancer(or breast cancer)targeted by HN-1;(5)Upon activation by collagen,DDR1 becomes internalized and compartmentalized in endosomes consistent with the determination of’energy-dependent clathrin-mediated endocytosis’as the HN-1 entry route and the identification of HN-1 entrapped vesicles as endosomes;and(6)DDR1 is essential for the development of mammary glands consistent with the common embryonic lineage rationale used to identify breast cancer as an additional target of HN-1.In summary,collagenactivated tyrosine kinase receptor DDR1 overexpressed in HNSCC assumes a critical role in metastasis.Further studies are warranted to assess HN-1 peptide’s interaction with DDR1 and the therapeutic potential of treating metastatic cancer.Additionally,advances in delivery(conformation,endocytic mechanism,repertoire of targeted cancers of HN-1 peptide),tracking(HN-1 conjugated imaging agents),and activity(HN-1 conjugated therapeutic agents)are described.CONCLUSION The discovery of DDR1 as HN-1 peptide’s putative receptor represents a significant advance as it enables identification of metastatic cancers or clinical application of previously developed therapeutics to block metastasis.展开更多
Despite significant discoveries in basic cancer research and improvements in treatment options and clinical outcomes,cancer remains a major public health concern worldwide.Today,the main focus of cancer research is the...Despite significant discoveries in basic cancer research and improvements in treatment options and clinical outcomes,cancer remains a major public health concern worldwide.Today,the main focus of cancer research is the signaling pathways that are crucial for cell survival,cell proliferation,and cell migration.The aberrant expression of proteins involved in these signaling pathways often leads to abnormal cell growth,cell metastasis,and invasion of healthy tis-sues.One such protein is discoidin domain receptor 1(DDR1)which belongs to the family of receptor tyrosine kinases(RTKs)and is activated upon collagen binding,as a result,downstream signaling pathways are stimulated which are responsible for cell survival,cell growth,adhesion,extracellular matrix remodeling,and cell migration.DDR1 is found to have abnormally elevated expression in various solid tumors,implying a critical role in cancer progression.Tradi-tional cancer treatment involves the use of cytotoxic drugs,chemotherapy,radiotherapy,and surgery,which do not pro-vide long-term survival and often result in cancer recurrence.Numerous small-molecule kinase inhibitors have been synthesized against RTKs including DDR1 and have been highly efficacious in tumor reduction.More recently,targeting the DDR1 extracellular domain(ECD)has garnered much attention from researchers,as inhibiting the DDR1-collagen binding has been attributed to maximizing the likelihood of the combined cytotoxic effect of both immune cells and tar-geted drugs.This review focuses on the structure,function,activation,and signaling partners of DDR1,its role in different solid tumors,andfinally discusses about designing more DDR1 non-kinase inhibitors as promising therapeutic strategies against DDR1-driven tumors.展开更多
The effect of Rg1,a saponin extracted froin Panax ginseng, on the phenotype,receptor and the activity of protein tyrosine kinase (PTK) of lymphocytes isolated from 7 healthy oldpersons were studied. The CD25, CD45RA a...The effect of Rg1,a saponin extracted froin Panax ginseng, on the phenotype,receptor and the activity of protein tyrosine kinase (PTK) of lymphocytes isolated from 7 healthy oldpersons were studied. The CD25, CD45RA and CD45RO phenotypes of lymphocytes were 4eter-mined by indirect immunofluorescence technique. The percentage of CD25, CD45RA and CD45ROpositive lymphocytes was 38.3%±17.3%, 46.0% 15.1%, and 52.6%±14.1% respectively after incu-bation with PHA (5 μ±/ml) for 72 hours. However, there were 58.0%±12.5%, CD25, 64.1% ± 12.4%,CD45RA, and 74.0%±8.0%, CD45RO positive cells in the presence of Rg, ( 1μg/ml) along with PHA(5 μg/ml) over the sanie period of incubation. A significant increase was induced by Rgi (P<0.05).The activities of PTK in the cytoplasm and membrane of lymphocytes were measured by ELISAmcthod after incubation with PHA or PHA+Rg1. The absorbance value of PTK activity in cytoplasmafter 72 hr incubation was 0. 120±0.020 in PHA group, but 0. 1 38±0.015 in PHA+Rg1 group. In thelymphocyte membrane, it was 0.374± 0.060 in PHA group and 0.403 ± 0.008 in PHA+Rg1 group(P<0.001). These results showed that Rgi significantly arid simultaneously increased both the PT Kactivity and the expression of phenotype of lymphocytes.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
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
文摘BACKGROUND Less than 0.5%of intravenously injected drugs reach tumors,contributing to side effects.To limit damage to healthy cells,various delivery vectors have been formulated;yet,previously developed vectors suffer from poor penetration into solid tumors.This issue was resolved by the discovery of HN-1 peptide isolated via biopanning a phage-display library.HN-1 targets human head and neck squamous cell carcinoma(HNSCC)(breast,thyroid;potentially lung,cervix,uterine,colon cancer),translocates across the cell membrane,and efficiently infiltrates solid tumors.HN-1 peptide has been conjugated to various anticancer drugs and imaging agents though the identity of its receptor remained enigmatic.AIM To decipher the clues that pointed to retinoblastoma(Rb)-regulated discoidindomain receptor 1 as the putative receptor for HN-1 is described.METHODS HN-1 peptide was synthesized and purified using reverse-phase highperformance liquid chromatography and gel electrophoresis.The predicted mass was confirmed by mass spectroscopy.To image the 3-dimensional structure of HN-1 peptide,PyMOL was used.Molecular modeling was also performed with PEP-FOLD3 software via RPBS bioinformatics web portal(INSERM,France).The immunohistochemistry results of discoidin domain receptor 1(DDR1)protein were obtained from the publicly accessible database in the Human Protein Atlas portal,which contained the images of immunohistochemically labeled human cancers and the corresponding normal tissues.RESULTS The clues that led to DDR1 involved in metastasis as the putative receptor mediating HN-1 endocytosis are the following:(1)HN-1 is internalized in phosphate-buffered saline and its uptake is competitively inhibited;(2)HN-1(TSPLNIHNGQKL)exhibits similarity with a stretch of amino acids in alpha5 beta3 integrin(KLLITIHDRKEF).Aside from two identical residues(Ile-His)in the middle,the overall distribution of polar and nonpolar residues throughout the sequences is nearly identical.As HN-1 sequence lacks the Arg-Gly-Asp motif recognized by integrins,HN-1 may interact with an"integrin-like"molecule.The tertiary structure of both peptides showed similarity at the 3-dimensional level;(3)HN-1 is internalized by attached cells but not by suspended cells.As culture plates are typically coated with collagen,collagen-binding receptor(expressed by adherent but not suspended cells)may represent the receptor for HN-1;(4)DDR1 is highly expressed in head and neck cancer(or breast cancer)targeted by HN-1;(5)Upon activation by collagen,DDR1 becomes internalized and compartmentalized in endosomes consistent with the determination of’energy-dependent clathrin-mediated endocytosis’as the HN-1 entry route and the identification of HN-1 entrapped vesicles as endosomes;and(6)DDR1 is essential for the development of mammary glands consistent with the common embryonic lineage rationale used to identify breast cancer as an additional target of HN-1.In summary,collagenactivated tyrosine kinase receptor DDR1 overexpressed in HNSCC assumes a critical role in metastasis.Further studies are warranted to assess HN-1 peptide’s interaction with DDR1 and the therapeutic potential of treating metastatic cancer.Additionally,advances in delivery(conformation,endocytic mechanism,repertoire of targeted cancers of HN-1 peptide),tracking(HN-1 conjugated imaging agents),and activity(HN-1 conjugated therapeutic agents)are described.CONCLUSION The discovery of DDR1 as HN-1 peptide’s putative receptor represents a significant advance as it enables identification of metastatic cancers or clinical application of previously developed therapeutics to block metastasis.
基金T.J.is supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB0490000)S.B.and S.M.M.M.are supported by Chinese Academy of Sciences-The Alliance of International Science Organizations for Young Talents+1 种基金W.Z.is supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB0490000)P.Z.is supported by the opening project of National&Local Joint Engineering Research Center of Deep Processing Technology for Aquatic Products.
文摘Despite significant discoveries in basic cancer research and improvements in treatment options and clinical outcomes,cancer remains a major public health concern worldwide.Today,the main focus of cancer research is the signaling pathways that are crucial for cell survival,cell proliferation,and cell migration.The aberrant expression of proteins involved in these signaling pathways often leads to abnormal cell growth,cell metastasis,and invasion of healthy tis-sues.One such protein is discoidin domain receptor 1(DDR1)which belongs to the family of receptor tyrosine kinases(RTKs)and is activated upon collagen binding,as a result,downstream signaling pathways are stimulated which are responsible for cell survival,cell growth,adhesion,extracellular matrix remodeling,and cell migration.DDR1 is found to have abnormally elevated expression in various solid tumors,implying a critical role in cancer progression.Tradi-tional cancer treatment involves the use of cytotoxic drugs,chemotherapy,radiotherapy,and surgery,which do not pro-vide long-term survival and often result in cancer recurrence.Numerous small-molecule kinase inhibitors have been synthesized against RTKs including DDR1 and have been highly efficacious in tumor reduction.More recently,targeting the DDR1 extracellular domain(ECD)has garnered much attention from researchers,as inhibiting the DDR1-collagen binding has been attributed to maximizing the likelihood of the combined cytotoxic effect of both immune cells and tar-geted drugs.This review focuses on the structure,function,activation,and signaling partners of DDR1,its role in different solid tumors,andfinally discusses about designing more DDR1 non-kinase inhibitors as promising therapeutic strategies against DDR1-driven tumors.
文摘The effect of Rg1,a saponin extracted froin Panax ginseng, on the phenotype,receptor and the activity of protein tyrosine kinase (PTK) of lymphocytes isolated from 7 healthy oldpersons were studied. The CD25, CD45RA and CD45RO phenotypes of lymphocytes were 4eter-mined by indirect immunofluorescence technique. The percentage of CD25, CD45RA and CD45ROpositive lymphocytes was 38.3%±17.3%, 46.0% 15.1%, and 52.6%±14.1% respectively after incu-bation with PHA (5 μ±/ml) for 72 hours. However, there were 58.0%±12.5%, CD25, 64.1% ± 12.4%,CD45RA, and 74.0%±8.0%, CD45RO positive cells in the presence of Rg, ( 1μg/ml) along with PHA(5 μg/ml) over the sanie period of incubation. A significant increase was induced by Rgi (P<0.05).The activities of PTK in the cytoplasm and membrane of lymphocytes were measured by ELISAmcthod after incubation with PHA or PHA+Rg1. The absorbance value of PTK activity in cytoplasmafter 72 hr incubation was 0. 120±0.020 in PHA group, but 0. 1 38±0.015 in PHA+Rg1 group. In thelymphocyte membrane, it was 0.374± 0.060 in PHA group and 0.403 ± 0.008 in PHA+Rg1 group(P<0.001). These results showed that Rgi significantly arid simultaneously increased both the PT Kactivity and the expression of phenotype of lymphocytes.
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.
