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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 181 records · Page 10

MIF protects against oxygen-glucose deprivation-induced ototoxicity in HEI-OC1 cochlear cells by enhancement of Akt-Nrf2-HO-1 pathway

Highlights: • MIF attenuates OGD-induced cochlear cells injury. • MIF enhances Nrf2 and inhibit oxidative stress in cochlear cells. • Enhanced Akt-Nrf2-HO-1 pathway may mediates cochlear protection by MIF. Ischemia and oxidative stress play crucial roles in the pathophysiology of sudden sensorineural hearing loss (SSNHL). Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine and serves an important role in hearing function. The present study was designed to evaluate the effect of MIF on oxygen-glucose deprivation (OGD)-induced ototoxicity and to elucidate its molecular mechanism. In HEI-OC1 auditory cells, OGD reduced cell viability and increased supernatant lactate dehydrogenase (LDH) and MIF in a time-dependent manner. However, the reduced cell viability exerted by OGD was attenuated by antioxidant and MIF. Luciferase reporter assay demonstrated that MIF could activate NF-E2-related factor 2 (Nrf2), and real-time PCR showed increased mRNA expressions of Nrf2 and two Nrf2-responsive genes, including heme oxygenase-1 (HO-1) and NAD(P)H:quinone oxidoreductase 1 (NQO1). MIF also suppressed oxidative stress induced by OGD, as demonstrated by decreased MDA and increased GSH in cellular supernatant. Inhibition of Nrf2 using siRNA suppressed HO-1 protein expression, the protective effect on OGD-induced injury and decrease in oxidative stress by MIF. Moreover, MIF prevented OGD-induced reduction of Akt1 phosphorylation at Ser473. LY294002, an inhibitor of PI3K/Akt signaling, attenuated the enhancement of Nrf2 protein and protective effect of MIF in OGD-treated cochlear cells. We demonstrate that MIF protects cochlear cells against OGD-induced injury through activation of Akt-Nrf2-HO-1 pathway.

60 APPLIED LIFE SCIENCES↗

Lactate enhanced the effect of parathyroid hormone on osteoblast differentiation via GPR81-PKC-Akt signaling

Highlights: • Lactate induces osteoblast differentiation that mediated by PTH treatment. • The inducing effect of lactate is MCT-1 independent. • The inducing effect of lactate requires GPR81-PKC-Akt signaling. Osteoblast uses aerobic glycolysis to meet the metabolic needs in differentiation process. Lactate, the end product of glycolysis, presents in the environment with elevated PTH and osteoblast differentiation. Although previous findings showed that lactate promoted osteoblast differentiation, whether lactate affects PTH–mediated osteoblast differentiation is unclear. To investigate this, pre-osteoblast cell line MC3T3-E1 was treated PTH with or without physiological dose of lactate. Lactate increases ALP positive cell formation, increases ALP activity and expression of differentiation related markers, enriches the CREB transcriptional factor target genes in PTH treated cells. Using inhibitors for MCT-1 reveales that lactate effects are MCT-1 independent. Lactate selectively increases Akt and p38 activation but not Erk1/2 and β-Catenin activation. The inhibitors for Akt and p38 inhibit lactate effects on PTH mediated osteoblast differentiation. Using inhibitors for Gαi signaling of GPR81 further increases Alp mRNA levels in lactate and PTH co-treatment cells. However, with the inhibitors for Gβγ-PLC-PKC signaling, the effect of lactate on PTH mediated osteoblast differentiation is inhibited. Our data demonstrate that lactate activates GPR81-Gβγ-PLC-PKC-Akt signaling to regulate osteoblast differentiation that mediated by PTH treatment.

60 APPLIED LIFE SCIENCES↗

Notch signaling regulates the expression of glycolysis-related genes in a context-dependent manner during embryonic development

Highlights: • Notch does not regulate glycolysis genes during early embryonic development. • Notch regulates glycolysis genes differently in the brain at the larval stage. • Notch-mediated glycolysis gene regulation is context-dependent during development. Glycolysis, the classic pathway for producing energy, has been known to be involved in neural development. Notch signaling also contributes to neural development and regulation of glycolysis in various tissues. However, the role of Notch signaling in glycolysis-related gene regulation during neural development is poorly understood. Here, we analyzed mRNA expression patterns and levels of glucose transporters (GLUT) as well as rate-limiting enzymes in glycolysis using zebrafish mib1{sup ta52b} mutants, in which Notch signaling was deficient at the early embryonic and larval stages. Our results indicated that in neural tissues, Notch signaling positively regulates glut1a and glut3a expression and negatively regulates hk2 expression at the larval stage but may not regulate them during early embryonic stages. Therefore, these results suggest that Notch signaling regulates glycolysis-related gene expression in a context-dependent manner in neural tissues at different developmental stages.

60 APPLIED LIFE SCIENCES↗

Regulation of the regulator of G protein signaling 2 expression and cellular localization by PKA and PKC pathways in mouse granulosa cells

G protein-coupled receptor (GPCR) activation-mediated PKA and PKC pathways have been recognized to be important in ovarian physiology. Expression of regulator of G-protein signaling 2 (RGS2) has been reported in ovarian granulosa cells. The detailed mechanisms in PKA- and PKC-regulated RGS2 expression and cellular translocation in granulosa cells remain mostly unclear. PKA activator 8-bromo-cAMP and PKC activator phorbol-12, 13-didecanoate appeared to rapidly elevate both protein and mRNA levels and promoter activation of RGS2 gene. Two consensus Sp1 elements within the shortest 78 bp fragment of RGS2 promoter sequence were essential for the full responsiveness to PKA and PKC. PKC activation appeared to increase the RGS2 translocation from nucleus to cytosol. PKA- and PKC-mediated RGS2 transcription in a Sp-1-dependent manner and a PKC-mediated RGS2 intracellular translocation were noted in granulosa cells.

60 APPLIED LIFE SCIENCES↗

mir-127-3p inhibits the proliferation of myocytes by targeting KMT5a

MicroRNAs are a class of highly conserved ∼20 nucleotides non-coding RNAs that post-transcriptionally regulate gene expression. Many miRNAs were studied in the development of skeletal muscle, such as miR-1, miR-206, and miR-133. In our previous study, miR-127-3p was found highly expressed in porcine fetal skeletal muscle, whereas the detailed functions of miR-127-3p in muscle development is still unclear. In this study, we detected that miR-127-3p also highly expressed in skeletal muscle, cardiac muscle of adult mice and proliferative C2C12 cell lines. Overexpression of miR-127-3p almost has no effects on differentiation of C2C12 cell lines. However, miR-127-3p significantly inhibited the cell proliferation of C2C12 cells. Moreover, we identified KMT5a as a target gene that was down-regulated in both mRNA and protein level when miR-127-3p mimics were introduced. Furthermore, KMT5a overexpression in miR-127-3p treated cells rescued the influence of miR-127-3p on C2C12 proliferation. In brief, our data reveals that miR-127-3p regulates the proliferation of myocytes through KMT5a.

60 APPLIED LIFE SCIENCES↗

Vitamin D receptor ligands attenuate the inflammatory profile of IL-1β-stimulated human white preadipocytes via modulating the NF-κB and unfolded protein response pathways

Highlights: • IL-1β enhances the inflammatory profile of preadipocytes by post-translationally modifying relA of the NF-κB pathway. • Vitamin D ligands inhibit expression of pro-inflammatory factors in IL-1β-stimulated preadipocytes by decreasing phosphorylation or increasing methylation of relA. • Vitamin D ligands reduce secretion of proinflammatory factors from IL-1β-stimulated preadipocytes by increasing eIF-2α phosphorylation in the UPR pathway. Metaflammation in adipose tissue, which is characterized by increased local gene expression and secretion of pro-inflammatory factors, may contribute to the increased risk of metabolic complications in obesity. It has been suggested that IL-1β might induce metaflammation in adipose tissue via modulating the NF-κB signaling pathway. In our study, the mRNA and secretion levels of major pro-inflammatory factors including IL (interleukin)-1β, IL-6, IL-8, MCP (monocyte chemoattractant protein)-1 and RANTES (regulated on activation, normal T cell expressed and secreted) were measured as indicators of the inflammatory profile. We herein showed that IL-1β could induce adipose tissue metaflammation by enhancing the inflammatory profile of preadipocytes. Moreover, IL-1β could enhance pro-inflammatory gene expression by increasing the phosphorylation or decreasing the methylation of relA (NF-κB p65) of the NF-κB signaling pathway. VDR (vitamin D receptor) ligands have been shown to have anti-inflammatory properties in adipocytes. Likewise, our study demonstrated that the inflammatory profile of IL-1β-stimulated preadipocytes is significantly attenuated by VDR ligands 1α,25(OH){sub 2}D{sub 3}, ZK159222 and ZK191785. Importantly, we showed that ZK159222 and ZK191785 could inhibit pro-inflammatory gene expression by decreasing the phosphorylation or increasing the methylation of relA. Furthermore, pro-inflammatory secretion could be reduced by 1α,25(OH){sub 2}D{sub 3}, ZK159222 and ZK191785 via increasing the phosphorylation of eIF (eukaryotic translation initiation factor)-2α of the UPR (unfolded protein response) pathway. These observations suggest that the VDR ligands may be considered potential anti-inflammatory treatments for obesity associated metabolic complications.

60 APPLIED LIFE SCIENCES↗

Identification of cathepsin B as a novel target of hypoxia-inducible factor-1-alpha in HepG2 cells

Highlights: • Cathepsin B (CTSB) is a novel target gene of hypoxia-inducible factor-1-alpha (HIF-1α). • CTSB mRNA and protein levels can be up-regulated in a HIF-1α-dependent manner. • CTSB promoter activity can be elevated by the HIF-1α protein. • HIF-1α protein binds the CTSB promoter directly. Hypoxia-inducible factor-1-alpha (HIF-1α) activates the transcription of many genes that code for proteins involved in angiogenesis, glucose metabolism, cell proliferation/survival, and invasion/metastasis. However, the mechanisms between HIF-1 and its downstream target genes are still poorly understood. Our experimental results had shown that nuclear HIF-1α proteins were significantly induced after HepG2 cells treatment with 1% O{sub 2} for 6 h and reached the peak expression level in 24 h. Meanwhile, the results of RT-qPCR and Western-blotting showed that HIF-1α and cathepsin B (CTSB) expressions increased with a similar pattern in response to hypoxia in the HepG2 cells. Additionally, based on bioinformatics analysis, we identified a hypoxia response element in the CTSB promoter, indicating a possible association between HIF-1α and CTSB. Moreover, luciferase assay was performed to reflect the transcriptional activity mediated through the HIF-1α binding HRE within the CTSB promoter. Furthermore, electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (CHIP) revealed a specific HIF-1α binding activity to the CTSB gene promoter. For the first time, we demonstrated that CTSB is a new HIF-1α-target gene. We believe these findings will contribute to the research and development of neoplasm-targeted therapies.

60 APPLIED LIFE SCIENCES↗

Epithelial cell adhesion molecule expression in hepatic stem/progenitor cells is controlled by the molecular clock system

Highlights: • We investigated clock gene effects on EpCAM-positive cell induction in hepatitis. • Hepatitis in CLOCK mutant mice was severe compared with wild-type mice. • CLOCK regulated expression of LEF, which regulated EpCAM expression. • CLOCK was important for healing hepatitis. The circadian rhythm, which regulates various body functions, is transcriptionally controlled by a series of clock gene clusters. The clock genes are related to the pathology of various kinds of diseases. Although there is evidence of serious sleep disorders in patients with chronic hepatitis, the liver regeneration mechanism under chronic hepatitis conditions and its association with the clock genes are not clear. In this study, the influence of the circadian locomotor output cycles kaput (CLOCK), which is one of the clock genes, on a 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC)-induced hepatitis animal model was investigated. The appearance of potential hepatic stem-like cells (epithelial cell adhesion molecule [EpCAM]-positive cells) is an initial critical step in liver regeneration during chronic inflammation. The results showed a considerable number of hepatic EpCAM-positive cells in the wild-type (WT) mice 1 week after the DDC feeding. However, the number of EpCAM-positive cells in the Clock-mutant (Clk/Clk) mice decreased, and their hepatitis was worse compared with the WT mice. In addition, the expression of Epcam mRNA, which is a functional marker of potential hepatic stem-like cells, was controlled by LEF1, which was regulated by CLOCK. The results of this study will facilitate the elucidation of the liver regeneration mechanisms, including those at the molecular level, and may assist in the development of new treatment modalities in the future.

60 APPLIED LIFE SCIENCES↗

Circular RNA HIPK3 regulates human lens epithelial cells proliferation and apoptosis by targeting the miR-193a/CRYAA axis

Highlights: • CircRNA sequencing reveals 26 up-regulated and 75 down-regulated circRNAs in ARC. • CircHIPK3 is down-regulated in all three subtypes of ARC. • CircHIPK3 knockdown affects the cellular function in primary cultured HLECs. • CircHIPK3 exerts its role via modulation of circHIPK3/miR-193a/CRYAA axis in HLECs. Circular RNAs (circRNAs) are a novel class of non-coding RNAs generated from back splicing. Accumulating evidence has demonstrated their vital regulation in several biological processes and ocular diseases. However, the role of circRNAs in age-related cataract (ARC), the leading cause of visual impairment worldwide, is still unknown. CircRNA sequencing reveals that 101 circRNAs are differentially expressed between the capsules of transparent and ARC lenses, including 75 down-regulated circRNAs and 26 up-regulated circRNAs transcripts. Eight of 10 differentially expressed circRNAs are further verified by quantitative RT-PCRs. One highly conserved circRNA, circHIPK3, is significantly down-regulated in all cortical, nuclear and posterior subcapsular subtypes of ARC. The silencing of circHIPK3, but not HIPK3 mRNA, significantly accelerates apoptosis development upon oxidative stress and decreases cell viability and proliferation in primary cultured human lens epithelial cells (HLECs). The expression of α-SMA and vimentin was downregulated, while the expression of E-cadherin and ZO-1was upregulated, suggesting the repression of epithelial-mesenchymal transition after circHIPK3 knockdown. CircHIPK3 silencing increases miR-193a expression. miR-193a regulates CRYAA expression by targeting the binding site within the 3′UTR. Moreover, miR-193a decreases the viability and proliferation, and increases the apoptosis of HLECs upon oxidative stress. This study suggests that circRNAs are the potential regulators in cataractogenesis. CircHIPK3 regulates HLECs function through miR-193a-mediated CRYAA expression. This finding would provide a novel insight into the pathogenesis of ARC.

60 APPLIED LIFE SCIENCES↗

Tas2r125 functions as the main receptor for detecting bitterness of tea catechins in the oral cavity of mice

Highlights: • We identified mouse 5 bitter taste receptors (Tas2rs) which respond to tea catechin. • Among these receptors, Tas2r125 showed the strongest response to catechins. • The response profiles of Tas2r125 were consistent with the behavior profiles. • Tas2r125 expression was not observed in the tested tissues except the taste papillae. • Tas2r125 plays as the catechin receptor in the oral cavity. We attempted to identify mouse bitter taste receptors, Tas2rs, that respond to tea catechins. Among representative tea catechins, avoidance behavior of mice to (−)–epicatechin gallate (ECg) was the strongest, followed by (−)–epigallocatechin gallate (EGCg). Therefore, we measured ECg response using Tas2rs-expressing cells. Among the 35 members of Tas2r family, Tas2r108, 110, 113, 125, and 144 responded to ECg. Among these receptors, Tas2r113 and 125 also responded to EGCg. Because the response profiles of Tas2r125 were consistent with the results of the behavior assays, it was considered that Tas2r125 functions as the main receptor for detecting bitterness of tea catechins in the oral cavity. To determine the involvement of Tas2rs in the physiological action of catechins, mRNA expression of 5 Tas2rs was investigated in various tissues. Because mRNA expression of Tas2r108 was observed in some tissues including the gastrointestinal tract, it may be envisaged that Tas2r108 plays a part in exerting the physiological action of ECg. Tas2r125 expression was not observed in any of the tested tissues except the circumvallate papillae. Therefore, Tas2r125 was considered to mainly function in the events of catechin reception in the oral cavity.

60 APPLIED LIFE SCIENCES↗

Knockdown of ADAM17 inhibits cell proliferation and increases oxaliplatin sensitivity in HCT-8 colorectal cancer through EGFR-PI3K-AKT activation

Highlights: • High expression of ADAM17 is associated with oxaliplatin chemosensitivity. • Chronic oxaliplatin exposure established drug-resistant cell line HCT-8/L-OHP. • Down regulation of ADAM17 can enhance sensitivity and reverse resistance to oxaliplatin. • Downregulation of ADAM17 inhibit cell proliferation, induce apoptosis via EGFR/PI3K/AKT signaling pathway. We investigated the role of a disintegrin and metalloproteinase 17 (ADAM17) in chemo resistance, and to clarify the mechanism underlying reverse of L-OHP resistance by knockdown of ADAM17. CRC tissues with corresponding adjacent normal tissues were collected. The mRNA and protein expression of ADAM17 in tissues were detected by RT-qPCR, immunohistochemistry and Western blot. The prognostic impact of ADAM17 expression were then validated in TCGA database to confirm the results. Resistance to oxaliplatin was induced in HCT-8 (HCT-8/L-OHP) colorectal cancer cell line by exposing cell to increasing concentrations of L-OHP. MTT were used to evaluate the resistance to L-OHP. Subsequently, Knockdown of ADAM17 in HCT-8 and HCT-8/L-OHP cells to explore the mechanism through which ADAM17 shRNA reverses L-OHP resistance. Our result showed that ADAM17 was higher expression in the cancerous tissue and related to the chemosensitivity. Moreover, ADAM17 shRNA, AG1478 and LY294002 could inhibit cell proliferation, induce apoptosis and increase oxaliplatin sensitivity in HCT-8/L-OHP and parental colorectal cancer cell line, but nonsense shRNA did not show this effect. Western blot analysis further confirmed that EGFR/PI3K/AKT signaling pathway is involved in ADAM17 shRNA inhibiting proliferation and chemosensitivity of HCT-8/L-OHP and HCT-8 cells. The present study provides the evidence that downregulation of ADAM17 could increase the sensitivity to chemotherapy, inhibit cell proliferation, induce apoptosis, and reverse oxaliplatin resistance via suppression of the EGFR/PI3K/AKT signaling pathway in CRC.

60 APPLIED LIFE SCIENCES↗

Long non-coding RNA KCNQ1OT1 modulates oxaliplatin resistance in hepatocellular carcinoma through miR-7-5p/ ABCC1 axis

Highlights: • KCNQ1OT1 was significantly up-regulated in oxaliplatin-resistant HCC cells. • Knockdown of KCNQ1OT1 inhibited the cell proliferation, migration, invasion. • KCNQ1OT1 modulated oxaliplatin resistance in HCC through miR-7-5p/ ABCC1 axis. The underlying functions of long non-coding RNAs (lncRNAs) on chemoresistance in multiple cancers have been testified. However, the function and mechanism of lncRNAs on chemoresistance in hepatocellular carcinoma are still confused. In this study, we concentrated on the function and mechanism of KCNQ1OT1 on oxaliplatin resistance in hepatocellular carcinoma. Results showed that KCNQ1OT1 was significantly up-regulated in oxaliplatin-resistant HepG2 and Huh7 cells. Moreover, knockdown of KCNQ1OT1 inhibited the cell proliferation, migration, invasion and reduced the expression of drug-resistant gene (MRP5, MDR1, LRP1). Additionally, bioinformatics analysis and dual-luciferase reporter assay showed that miR-7-5p directly targeted the 3′-UTR of miR-7-5p and ABCC1 mRNA, indicating that KCNQ1OT1 regulated the expression of ABCC1 via endogenous sponging miR-7-5p. Conclusively, KCNQ1OT1 modulated oxaliplatin resistance in hepatocellular carcinoma through miR-7-5p/ABCC1 axis, indicating a novel approach for the treatment of hepatocellular carcinoma.

60 APPLIED LIFE SCIENCES↗

The miR-31-SOX10 axis regulates tumor growth and chemotherapy resistance of melanoma via PI3K/AKT pathway

Highlights: • Firstly found up-regulation of SOX10 and down-regulation of miR-31 in MM. • miR-31 regulated SOX10 by binding to its 3′UTR. • SOX10 regulated tumor growth and chemotherapy resistance of melanoma in vitro and in vivo. • The miR-31-SOX10 axis mediated tumor growth and drug resistance via activation of PI3K/AKT pathway. MicroRNAs were thought to play a regulatory role through complementarity to target messenger RNA (mRNA). Our previous study revealed a miR-31-SOX10 axis that regulated tumor growth and resistance to chemotherapy of melanoma. Up-regulation of SOX10 and down-regulation of miR-31 were found in melanoma tissues. SOX10 was further identified as a target of miR-31. Overexpression of SOX10 dramatically promoted melanoma cell proliferation and chemotherapy resistance both in vitro and in vivo. While enforced miR-31 expression suppressed cell growth and enhanced the chemosensitivity of melanoma cells, the re-expression of SOX10 rescued these effects by activating PI3K/AKT signaling pathway. In conclusion, our results demonstrated that SOX10 acted as an oncogene and was negatively regulated by miR-31, which supports the potential therapeutic strategy against melanoma by targeting the miR-31-SOX10 axis.

60 APPLIED LIFE SCIENCES↗

The role of lncRNA XIST/miR-211 axis in modulating the proliferation and apoptosis of osteoarthritis chondrocytes through CXCR4 and MAPK signaling

Long noncoding RNAs (lncRNAs) participate in multiple diverse diseases, including osteoarthritis (OA). Here, we explored the role of lncRNA XIST in OA and identified the potential molecular mechanisms. The expression of XIST in cartilage samples in patients with OA was significantly upregulated. XIST knockdown remarkably suppressed IL-1β-suppressed OA chondrocyte proliferation while promoted IL-1β-induced cell apoptosis. By employing online tools, miRNAs related to CXCR4, a major contributor to chondrocyte apoptosis, and XIST were selected. miR-211 expression could be significantly inhibited by IL-1β stimulation, and miR-211 negatively regulated XIST expression and CXCR4 protein levels. Through direct binding, XIST served as a ceRNA for miR-211 to counteract miR-211-mediated CXCR4 repression, thereby modulating chondrocyte proliferation and apoptosis through downstream MAPK signaling. In OA tissues, miR-211 expression was significantly downregulated while CXCR4 mRNA expression was upregulated. miR-211 was negatively correlated with XIST and CXCR4, respectively, while XIST and CXCR4 was positively correlated in tissue samples. In conclusion, the study revealed that lncRNA XIST can promote the proliferation of OA chondrocytes and promote apoptosis through the miR-211/CXCR4 axis. Thus, lncRNA XIST might be considered as a potential therapeutic target for OA treatment.

60 APPLIED LIFE SCIENCES↗

ZKSCAN3 promotes breast cancer cell proliferation, migration and invasion

Highlights: • ZKSCAN3 is upregulated in breast cancer tissue and cell lines. • Knocking down ZKSCAN3 suppresses breast cancer cell proliferation, enhances cell apoptosis and blocks cell cycle. • Knocking down ZKSCAN3 significantly inhibits breast cancer cell migration and invasion. • Knocking down ZKSCAN3 significantly inhibits breast tumor growth in vivo. • Knocking down ZKSCAN3 reduces activity of the Akt/mTOR pathway. ZKSCAN3, a zinc-finger transcription factor, which has been shown to be upregulated in several human cancer. However, the expression level, function and mechanism of ZKSCAN3 in breast cancer remains unknown. In the current study, immunohistochemistry, western blot and quantitative real time polymerase chain reaction (qRT-PCR) results showed that ZKSCAN3 was overexpressed in breast cancer tissue compared with normal breast tissue. Through analyzing the clinicopathological characteristics, we demonstrated that positive ZKSCAN3 expression predicted poor prognosis of patients with breast cancer. The expression level of ZKSCAN3 protein/mRNA in breast cancer cells (MCF-7 and MDA-MB-231) was higher than its expression in normal breast cells (HBL-100). Knocking down ZKSCAN3 via its short hairpin RNA (shRNA) in MCF-7 and MDA-MB-231 inhibited cell viability, migration and invasion. Western blot analysis showed that ZKSCAN3 silencing lead to significant decreases in the expression of Cyclin D1, B-cell lymphoma-2 (Bcl-2), and matrix metalloproteinase (MMP)-2/MMP-9, as well as increases in the expression of Bcl2 Associated X Protein (Bax) in breast cancer cells. Additionally, ZKSCAN3-shRNA expression markedly suppressed tumor growth in breast cancer xenograft mice. Finally, we demonstrated that silencing of ZKSCAN3 was able to inhibit Akt/mTOR signaling pathway by blocking p-Akt and p-mTOR protein expression in breast cancer cells. These results demonstrate that ZKSCAN3 plays a significant role in the progression of breast cancer. Therefore, ZKSCAN3 is a potential therapeutic target for breast cancer.

60 APPLIED LIFE SCIENCES↗

Glucocorticoid-induced CREB activation and myostatin expression in C2C12 myotubes involves phosphodiesterase-3/4 signaling

Muscle atrophy in metabolic conditions like chronic kidney disease (CKD) and diabetes are associated with glucocorticoid production, dysfunctional insulin/Akt/FoxO3 signaling and increased myostatin expression. We recently found that CREB, a transcription factor proposed to regulate myostatin expression, is highly phosphorylated in some wasting conditions. Based on a novel Akt-PDE3/4 signaling paradigm, we hypothesized that reduced Akt signaling contributes to CREB activation and myostatin expression. C2C12 myotubes were incubated with dexamethasone (Dex), an atrophy-inducing synthetic glucocorticoid. Akt/CREB signaling and myostatin expression were evaluated by immunoblot and qPCR analyses. Inhibitors of Akt, phosphodiesterase (PDE)-3/4, and protein kinase A (PKA) signaling were used to test our hypothesis. Incubating myotubes with Dex for 3–24 h inhibited Akt phosphorylation and enhanced CREB phosphorylation as well as myostatin mRNA and protein. Inhibition of PI3K/Akt signaling with LY294002 similarly increased CREB phosphorylation. Isobutyl-methylxanthine (IBMX, a pan PDE inhibitor), milrinone (PDE3 inhibitor) and rolipram (PDE4 inhibitor) augmented CREB phosphorylation and myostatin expression. Inhibition of protein kinase A by PKI reverted Dex- or IBMX-induced CREB phosphorylation and myostatin expression. Our study provides evidence supporting a newly identified mechanism by which a glucocorticoid-related reduction in Akt signaling contributes to myostatin expression via CREB activation.

60 APPLIED LIFE SCIENCES↗

miR-181d-5p-FOXP1 feedback loop modulates the progression of osteosarcoma

MicroRNAs (miRNAs) are playing more and more fundamental roles in the progress of human cancers. miR-181d-5p has not been fully elucidated in human cancers. In this study, we aimed to investigate the biological function and mechanism of miR-181d-5p in osteosarcoma (OS). At first, the expression conditions of miR-181d-5p were identified in OS tissues and cell lines. Downregulation of miR-181d-5p was identified to be a significant prognostic factor for patients with OS. Using the bioinformatics analysis, the putative target mRNA (FOXP1) of miR-181d-5p was found out. Similarly, the expression conditions and prognostic value of FOXP1 were identified in OS. To validate the tumor suppressive role of miR-181d-5p in OS, gain or loss of function assays were carried out in OS cell lines. The results indicated the anti-oncogenic function of miR-181d-5p in OS. Subsequently, the oncogenic function of FOXP1 in OS was identified by functional assays. Rescue assays manifested that the oncogenic function of FOXP1 can be partially reversed by miR-181d-5p. Combining with the result of luciferase reporter assay, we confirmed that miR-181d-5p can act as a tumor suppressor in OS via targeting FOXP1. Further mechanism experiments revealed that FOXP1 can suppressed the transcription activity of miR-181d-5p by acting as a transcription inhibitor. In conclusion, our study revealed that miR-181d-5p-FOXP1 feedback loop modulates cell proliferation and metastasis in osteosarcoma.

60 APPLIED LIFE SCIENCES↗

Correlation between high expression levels of jumonji domain-containing 4 and short survival in cases of colon adenocarcinoma

Highlights: • The play an important role of JMJD4 high expression in tumorgenesis of colon adenocarcinoma. • JMJD4 protein expression in colon adenocarcinoma was associated with histological grade and M-class. • The high expression of JMJD4 was significantly related with poor survival in patients with colon adenocarcinoma. • Cox proportional-hazards model analysis indicated JMJD4 could be a prognostic indicator for overall survival. In this study, we investigated the expression of jumonji domain-containing 4 (JMJD4) in colon adenocarcinoma (CA) look for evidences for future studies on clinical diagnostic and prognostic value. The immunohistochemical (IHC) reactivity of JMJD4 was assessed in human tissue microarrays using monoclonal antibodies. An initial investigation revealed that the expression of JMJD4 protein was significantly higher in tumor tissue of the colon and liver than in normal tissue. Upon further investigation, we observed significant positivity of JMJD4 between 59 paired samples from CA tissue and adjacent normal tissue. JMJD4 protein expression in CA differed significantly according to the histological grade and M-class (distant metastasis). We also determined that the mRNA or protein expression of JMJD4 was significantly associated with poor survival in patients with CA. Finally, univariate and multivariate analysis revealed that JMJD4 expression could be a prognostic indicator for patients with CA and may provide a new target for the development of novel therapies for the treatment of CA.

60 APPLIED LIFE SCIENCES↗