Invadopodia are actin-rich structures and their formation is implicated in cancer invasion and me... more Invadopodia are actin-rich structures and their formation is implicated in cancer invasion and metastasis. Growing evidence has shown that noncoding RNAs (ncRNAs) play important roles in pathological conditions, including tumorigenesis and metastasis. Although this is still a new area of research, ncRNAs appear to be promising biomarkers and therapeutic targets for cancer metastasis. However, understanding the roles of ncRNAs in invadopodia is still in the early stages and far from clinical application. In this mini-review, we summarize the roles of ncRNAs in invadopodia functions and discuss them in a therapeutic context. The current challenges and gaps in this field are also raised, and we provide some open questions to facilitate new ideas in targeting invadopodia in anticancer therapy.
International journal of physiology, pathophysiology and pharmacology, 2019
The growth of neurites underlies the axonal pathfinding and synaptic formation during neuronal de... more The growth of neurites underlies the axonal pathfinding and synaptic formation during neuronal development and regeneration. Neurite growth is regulated by specific interactions between growth cone receptors and their ligands that function as molecular cues existing in microenvironments. Neurexins (NRXNs) are concentrated on growth cones and they may function to constrain axonal branches of invertebrate neurons. The present study explored the role of NRXN-1α in regulating neurite growth of mammalian neurons. Results showed that transfecting an effective NRXN-1α siRNA to cultured rat hippocampal neurons significantly increased neurite length. Adding NRXN-1α ligands including neuroligin (NLGN) peptide and/or α-latrotoxin (α-LTX) to the culture media largely decreased neurite growth of naïve neurons in a Ca2+-dependent manner, but had no effect on neurite growth of neurons transfected with NRXN-1α siRNA. Our results suggest that NRXN-1α regulates neurite development of mammalian neurons.
Long-term dietary curcumin (>12 wk) improves metabolic homeostasis in obese mice by sensitizin... more Long-term dietary curcumin (>12 wk) improves metabolic homeostasis in obese mice by sensitizing insulin signaling and reducing hepatic gluconeogenesis. Whether these occur only secondary to its chronic anti-inflammatory and antioxidative functions is unknown. In this study, we assessed the insulin sensitization effect of short-term curcumin gavage in a rapid dexamethasone-induced insulin resistance mouse model, in which the chronic anti-inflammatory function is eliminated. Six-week-old male C57BL/6 mice received an intraperitoneal injection of dexamethasone (100 mg/kg body weight) or phosphate-buffered saline every day for 5 d, with or without simultaneous curcumin gavage (500 mg/kg body weight). On day 7, insulin tolerance tests were performed. After a booster dexamethasone injection and curcumin gavage on day 8, blood glucose and insulin concentrations were measured. Liver tissues were collected on day 10 for quantitative polymerase chain reaction and Western blotting to assess...
The scaffold protein, XB130, regulates cell growth, survival and migration. Yeast-2-hybrid screen... more The scaffold protein, XB130, regulates cell growth, survival and migration. Yeast-2-hybrid screening suggests that XB130 interacts with another scaffold protein, Tks5. We hypothesized that XB130 and Tks5 form a macromolecular complex to mediate signal transduction cascades for the regulation of cell growth and survival. Co-immunoprecipitation demonstrated that XB130 and Tks5 interact endogenously and form a complex with Src tyrosine kinase. Structure-function studies showed that the fifth SH3 domain of Tks5 binds to the N-terminus of XB130 that contains polyproline rich motifs. Cell growth and survival studies revealed that downregulation of XB130 and/or Tks5 reduced cell proliferation, resulting in cell cycle inhibition at the G1 phase and increased caspase 3 activity and apoptosis. Moreover, cell proliferation and survival were increased by overexpression of XB130 or Tks5 but decreased when XB130/Tks5 binding was disrupted by overexpression of XB130 N-terminal deleted mutant and/o...
Glioblastomas are progressive brain tumors with devastating proliferative and invasive characteri... more Glioblastomas are progressive brain tumors with devastating proliferative and invasive characteristics. Ion channels are the second largest target class for drug development. In this study, we investigated the effects of the TRPM7 inhibitor carvacrol on the viability, resistance to apoptosis, migration, and invasiveness of the human U87 glioblastoma cell line.The expression levels of TRPM7 mRNA and protein in U87 cells were detected by RT-PCR, western blotting and immunofluorescence. TRPM7 currents were recorded using whole-cell patch-clamp techniques. An MTT assay was used to assess cell viability and proliferation. Wound healing and transwell experiments were used to evaluate cell migration and invasion. Protein levels of p-Akt/t-Akt, p-ERK1/2/t-ERK1/2, cleaved caspase-3, MMP-2 and phosphorylated cofilin were also detected.TRPM7 mRNA and protein expression in U87 cells is higher than in normal human astrocytes. Whole-cell patch-clamp recording showed that carvacrol blocks recombin...
International journal of physiology, pathophysiology and pharmacology, 2011
Transforming growth factor-beta 1 (TGF-β1) is an inflammation-related cytokine. Its expression in... more Transforming growth factor-beta 1 (TGF-β1) is an inflammation-related cytokine. Its expression in the brain increases under conditions of neurodegenerative diseases and injuries. Previous studies have shown that genomic alterations of TGF-β1 expression in the brain cause neurodegenerative changes in aged mice. The present study revealed that increased production of TGF-β1 in transgenic mice resulted in gliosis at young ages. In addition, the increased TGF-β1 augmented the expression of some key subunits of α-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid (AMPA) and N-methyl-D-aspartate (NMDA) receptors in the hippocampus. Treatment of cultured hippocampal neurons with TGF-β1 facilitated neurite outgrowth and enhanced glutamate-evoked currents. Together, these data suggest that increased TGF-β1 alters ionotropic glutamate receptor expression and function in the hippocampus.
Ganoderma lucidum is a herbal mushroom known to have many health benefits, including the inhibiti... more Ganoderma lucidum is a herbal mushroom known to have many health benefits, including the inhibition of tumor cell growth. However, the effect of Ganoderma lucidum on epithelial ovarian cancer (EOC), the most fatal gynecological malignancy, has not yet been reported. In this study, we determined whether Ganoderma lucidum regulates EOC cell activity. Using several cell lines derived from EOC, we found that Ganoderma lucidum strongly decreased cell numbers in a dose-dependent manner. Ganoderma lucidum also inhibited colony formation, cell migration and spheroid formation. In particular, Ganoderma lucidum was effective in inhibiting cell growth in both chemosensitive and chemoresistant cells and the treatment with Ganoderma lucidum significantly enhanced the effect of cisplatin on EOC cells. Furthermore, Ganoderma lucidum induced cell cycle arrest at the G2/M phase and also induced apoptosis by activating caspase 3. Finally, Ganoderma lucidum increased p53 but inhibited Akt expression. ...
Sets of deregulated microRNAs (miRNAs), termed miRNA signatures, are promising biomarkers for can... more Sets of deregulated microRNAs (miRNAs), termed miRNA signatures, are promising biomarkers for cancer. Validation of miRNA signatures requires a technique that is accurate, sensitive, capable of detecting multiple miRNAs, fast, robust, and not cost-prohibitive. Direct quantitative analysis of multiple miRNAs (DQAMmiR) is a capillary electrophoresis (CE)-based hybridization assay that was suggested as a methodological platform for validation and clinical use of miRNA signatures. While satisfying the other requirements, DQAMmiR is not sufficiently sensitive to detect low-abundance miRNAs. Here, we solve this problem by combining DQAMmiR with the preconcentration technique, isotachophoresis (ITP). The sensitivity improved 100 times (to 1 pM) allowing us to detect low-abundance miRNAs in an RNA extract. Importantly, ITP-DQAMmiR can be performed in a fully automated mode using a commercial CE instrument making it suitable for practical applications.
Acetylcholinesterase (AChE) exerts noncatalytic activities on neural cell differentiation, adhesi... more Acetylcholinesterase (AChE) exerts noncatalytic activities on neural cell differentiation, adhesion, and neuritogenesis independently of its catalytic function. The noncatalytic functions of AChE have been attributed to its peripheral anionic site (PAS)-mediated protein-protein interactions. Structurally, AChE is highly homologous to the extracellular domain of neuroligin, a postsynaptic transmembrane molecule that interacts with presynaptic β-neurexins, thus facilitating synaptic formation and maturation. Potential effects of AChE expression on synaptic transmission, however, remain unknown. Using electrophysiology, immunocytochemistry, and molecular biological approaches, this study investigated the role of AChE in the regulation of synaptic formation and functions. We found that AChE was highly expressed in cultured embryonic hippocampal neurons at early culture days, particularly in dendritic compartments including the growth cone. Subsequently, the expression level of AChE decl...
We have previously reported that Nodal, a member of the TGF-β superfamily, acts through activin r... more We have previously reported that Nodal, a member of the TGF-β superfamily, acts through activin receptor-like kinase 7 (ALK7) to inhibit ovarian cancer cell proliferation. To determine the mechanism underlying their effects, a cell cycle gene array was performed and cyclin G2 mRNA was found to be strongly up-regulated by Nodal and ALK7. To study the function and regulation of cyclin G2 in ovarian cancer cells, expression constructs were generated. We found that cyclin G2 protein level decreased rapidly after transfection, and this decrease was prevented by 26S proteasome inhibitors. Immunoprecipitation and pull-down studies showed that ubiquitin, Skp1, and Skp2 formed complexes with cyclin G2. Knockdown of Skp2 by siRNA increased, whereas overexpression of Skp2 decreased cyclin G2 levels. Nodal and ALK7 decreased the expression of Skp1 and Skp2 and increased cyclin G2 levels. Overexpression of cyclin G2 inhibited cell proliferation whereas cyclin G2-siRNA reduced the antiproliferati...
Invadopodia are actin-rich structures and their formation is implicated in cancer invasion and me... more Invadopodia are actin-rich structures and their formation is implicated in cancer invasion and metastasis. Growing evidence has shown that noncoding RNAs (ncRNAs) play important roles in pathological conditions, including tumorigenesis and metastasis. Although this is still a new area of research, ncRNAs appear to be promising biomarkers and therapeutic targets for cancer metastasis. However, understanding the roles of ncRNAs in invadopodia is still in the early stages and far from clinical application. In this mini-review, we summarize the roles of ncRNAs in invadopodia functions and discuss them in a therapeutic context. The current challenges and gaps in this field are also raised, and we provide some open questions to facilitate new ideas in targeting invadopodia in anticancer therapy.
International journal of physiology, pathophysiology and pharmacology, 2019
The growth of neurites underlies the axonal pathfinding and synaptic formation during neuronal de... more The growth of neurites underlies the axonal pathfinding and synaptic formation during neuronal development and regeneration. Neurite growth is regulated by specific interactions between growth cone receptors and their ligands that function as molecular cues existing in microenvironments. Neurexins (NRXNs) are concentrated on growth cones and they may function to constrain axonal branches of invertebrate neurons. The present study explored the role of NRXN-1α in regulating neurite growth of mammalian neurons. Results showed that transfecting an effective NRXN-1α siRNA to cultured rat hippocampal neurons significantly increased neurite length. Adding NRXN-1α ligands including neuroligin (NLGN) peptide and/or α-latrotoxin (α-LTX) to the culture media largely decreased neurite growth of naïve neurons in a Ca2+-dependent manner, but had no effect on neurite growth of neurons transfected with NRXN-1α siRNA. Our results suggest that NRXN-1α regulates neurite development of mammalian neurons.
Long-term dietary curcumin (>12 wk) improves metabolic homeostasis in obese mice by sensitizin... more Long-term dietary curcumin (>12 wk) improves metabolic homeostasis in obese mice by sensitizing insulin signaling and reducing hepatic gluconeogenesis. Whether these occur only secondary to its chronic anti-inflammatory and antioxidative functions is unknown. In this study, we assessed the insulin sensitization effect of short-term curcumin gavage in a rapid dexamethasone-induced insulin resistance mouse model, in which the chronic anti-inflammatory function is eliminated. Six-week-old male C57BL/6 mice received an intraperitoneal injection of dexamethasone (100 mg/kg body weight) or phosphate-buffered saline every day for 5 d, with or without simultaneous curcumin gavage (500 mg/kg body weight). On day 7, insulin tolerance tests were performed. After a booster dexamethasone injection and curcumin gavage on day 8, blood glucose and insulin concentrations were measured. Liver tissues were collected on day 10 for quantitative polymerase chain reaction and Western blotting to assess...
The scaffold protein, XB130, regulates cell growth, survival and migration. Yeast-2-hybrid screen... more The scaffold protein, XB130, regulates cell growth, survival and migration. Yeast-2-hybrid screening suggests that XB130 interacts with another scaffold protein, Tks5. We hypothesized that XB130 and Tks5 form a macromolecular complex to mediate signal transduction cascades for the regulation of cell growth and survival. Co-immunoprecipitation demonstrated that XB130 and Tks5 interact endogenously and form a complex with Src tyrosine kinase. Structure-function studies showed that the fifth SH3 domain of Tks5 binds to the N-terminus of XB130 that contains polyproline rich motifs. Cell growth and survival studies revealed that downregulation of XB130 and/or Tks5 reduced cell proliferation, resulting in cell cycle inhibition at the G1 phase and increased caspase 3 activity and apoptosis. Moreover, cell proliferation and survival were increased by overexpression of XB130 or Tks5 but decreased when XB130/Tks5 binding was disrupted by overexpression of XB130 N-terminal deleted mutant and/o...
Glioblastomas are progressive brain tumors with devastating proliferative and invasive characteri... more Glioblastomas are progressive brain tumors with devastating proliferative and invasive characteristics. Ion channels are the second largest target class for drug development. In this study, we investigated the effects of the TRPM7 inhibitor carvacrol on the viability, resistance to apoptosis, migration, and invasiveness of the human U87 glioblastoma cell line.The expression levels of TRPM7 mRNA and protein in U87 cells were detected by RT-PCR, western blotting and immunofluorescence. TRPM7 currents were recorded using whole-cell patch-clamp techniques. An MTT assay was used to assess cell viability and proliferation. Wound healing and transwell experiments were used to evaluate cell migration and invasion. Protein levels of p-Akt/t-Akt, p-ERK1/2/t-ERK1/2, cleaved caspase-3, MMP-2 and phosphorylated cofilin were also detected.TRPM7 mRNA and protein expression in U87 cells is higher than in normal human astrocytes. Whole-cell patch-clamp recording showed that carvacrol blocks recombin...
International journal of physiology, pathophysiology and pharmacology, 2011
Transforming growth factor-beta 1 (TGF-β1) is an inflammation-related cytokine. Its expression in... more Transforming growth factor-beta 1 (TGF-β1) is an inflammation-related cytokine. Its expression in the brain increases under conditions of neurodegenerative diseases and injuries. Previous studies have shown that genomic alterations of TGF-β1 expression in the brain cause neurodegenerative changes in aged mice. The present study revealed that increased production of TGF-β1 in transgenic mice resulted in gliosis at young ages. In addition, the increased TGF-β1 augmented the expression of some key subunits of α-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid (AMPA) and N-methyl-D-aspartate (NMDA) receptors in the hippocampus. Treatment of cultured hippocampal neurons with TGF-β1 facilitated neurite outgrowth and enhanced glutamate-evoked currents. Together, these data suggest that increased TGF-β1 alters ionotropic glutamate receptor expression and function in the hippocampus.
Ganoderma lucidum is a herbal mushroom known to have many health benefits, including the inhibiti... more Ganoderma lucidum is a herbal mushroom known to have many health benefits, including the inhibition of tumor cell growth. However, the effect of Ganoderma lucidum on epithelial ovarian cancer (EOC), the most fatal gynecological malignancy, has not yet been reported. In this study, we determined whether Ganoderma lucidum regulates EOC cell activity. Using several cell lines derived from EOC, we found that Ganoderma lucidum strongly decreased cell numbers in a dose-dependent manner. Ganoderma lucidum also inhibited colony formation, cell migration and spheroid formation. In particular, Ganoderma lucidum was effective in inhibiting cell growth in both chemosensitive and chemoresistant cells and the treatment with Ganoderma lucidum significantly enhanced the effect of cisplatin on EOC cells. Furthermore, Ganoderma lucidum induced cell cycle arrest at the G2/M phase and also induced apoptosis by activating caspase 3. Finally, Ganoderma lucidum increased p53 but inhibited Akt expression. ...
Sets of deregulated microRNAs (miRNAs), termed miRNA signatures, are promising biomarkers for can... more Sets of deregulated microRNAs (miRNAs), termed miRNA signatures, are promising biomarkers for cancer. Validation of miRNA signatures requires a technique that is accurate, sensitive, capable of detecting multiple miRNAs, fast, robust, and not cost-prohibitive. Direct quantitative analysis of multiple miRNAs (DQAMmiR) is a capillary electrophoresis (CE)-based hybridization assay that was suggested as a methodological platform for validation and clinical use of miRNA signatures. While satisfying the other requirements, DQAMmiR is not sufficiently sensitive to detect low-abundance miRNAs. Here, we solve this problem by combining DQAMmiR with the preconcentration technique, isotachophoresis (ITP). The sensitivity improved 100 times (to 1 pM) allowing us to detect low-abundance miRNAs in an RNA extract. Importantly, ITP-DQAMmiR can be performed in a fully automated mode using a commercial CE instrument making it suitable for practical applications.
Acetylcholinesterase (AChE) exerts noncatalytic activities on neural cell differentiation, adhesi... more Acetylcholinesterase (AChE) exerts noncatalytic activities on neural cell differentiation, adhesion, and neuritogenesis independently of its catalytic function. The noncatalytic functions of AChE have been attributed to its peripheral anionic site (PAS)-mediated protein-protein interactions. Structurally, AChE is highly homologous to the extracellular domain of neuroligin, a postsynaptic transmembrane molecule that interacts with presynaptic β-neurexins, thus facilitating synaptic formation and maturation. Potential effects of AChE expression on synaptic transmission, however, remain unknown. Using electrophysiology, immunocytochemistry, and molecular biological approaches, this study investigated the role of AChE in the regulation of synaptic formation and functions. We found that AChE was highly expressed in cultured embryonic hippocampal neurons at early culture days, particularly in dendritic compartments including the growth cone. Subsequently, the expression level of AChE decl...
We have previously reported that Nodal, a member of the TGF-β superfamily, acts through activin r... more We have previously reported that Nodal, a member of the TGF-β superfamily, acts through activin receptor-like kinase 7 (ALK7) to inhibit ovarian cancer cell proliferation. To determine the mechanism underlying their effects, a cell cycle gene array was performed and cyclin G2 mRNA was found to be strongly up-regulated by Nodal and ALK7. To study the function and regulation of cyclin G2 in ovarian cancer cells, expression constructs were generated. We found that cyclin G2 protein level decreased rapidly after transfection, and this decrease was prevented by 26S proteasome inhibitors. Immunoprecipitation and pull-down studies showed that ubiquitin, Skp1, and Skp2 formed complexes with cyclin G2. Knockdown of Skp2 by siRNA increased, whereas overexpression of Skp2 decreased cyclin G2 levels. Nodal and ALK7 decreased the expression of Skp1 and Skp2 and increased cyclin G2 levels. Overexpression of cyclin G2 inhibited cell proliferation whereas cyclin G2-siRNA reduced the antiproliferati...
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