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At least 613 records · Page 34

Microglia support neural stem cell maintenance and growth

Increasing evidence suggests that disease-associated microglia play a protective role in neurodegenerative diseases. Microglia are known to polarize into two reciprocate forms in response to external cues - inflammatory M1 state and anti-inflammatory M2 state. These cells perform key functions in the development of the brain, such as circuit refinement, neurogenesis, and neuronal growth. In this study, we analyzed the secretion effect of microglia on neural stem/progenitor cell (NSPC) proliferation and differentiation. We cultured adult mouse-derived NSPCs in a conditioned medium from BV2 immortalized microglia without growth factors and evaluated their differentiation. When cultivated with BV2-derived soluble factors in the presence of basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF), NSPCs were able to maintain Nestin expression and showed increased proliferation compared with those cells cultivated with bFGF and EGF only. Moreover, conditioned media from M2-polarized primary microglia, stimulated by IL-10/IL-13, showed supportive effect on NSPC proliferation. These data suggest that microglia support neural stem cell proliferation through secreting neuro-nutritious soluble factors.

60 APPLIED LIFE SCIENCES↗

TrxR2 deficiencies promote chondrogenic differentiation and induce apoptosis of chondrocytes through mitochondrial reactive oxygen species

Thioredoxin reductase 2 (TrxR2) is a selenium (Se) containing protein. Se deficiency is associated with an endemic osteoarthropathy characterized by impaired cartilage formation. It is unclear whether TrxR2 have roles in cartilage function. We examined the effects of TrxR2 on chondrogenic ATDC5 cells through shRNA-mediated gene silencing of TrxR2. We demonstrated TrxR2 deficiencies could enhance chondrogenic differentiation and apoptosis of ATDC5 cells. TrxR2 deficiencies increased accumulation of cartilage glycosaminoglycans (GAGs) and mineralization. TrxR2 deficiencies also stimulated expression of extracellular (ECM) gene including Collagen II and Aggrecan. The enhanced chondrogenic properties were further confirmed by activation of Akt signaling which are required for chondrogenesis. In addition, TrxR2 deficiencies promoted chondrocyte proliferation through acceleration of cell cycle progression by increase in both S and G2/M phase cell distribution accompanied with induction of parathyroid hormone-related protein (PTHrP). Moreover, TrxR2 deficiencies induced chondrocyte death via apoptosis and increased cell sensitivity to exogenous oxidative stress. Furthermore, TrxR2 deficiencies induced emission of mitochondrial reactive oxygen species (ROS) without alteration of mitochondrial membrane potential and intracellular ATP content. Finally, treatment of TrxR2 deficiency cells with N-acetylcysteine (NAC) inhibited mitochondrial ROS production and chondrocyte apoptosis. NAC also prevented chondrogenic differentiation of TrxR2 deficiency cells by suppression of ECM gene expression, GAGs accumulation and mineralization, as well as attenuation of Akt signaling. Thus, TrxR2-mediated mitochondrial integrity is indispensable for chondrogenic differentiation of ATDC5 cells. TrxR2 deficiency-induced impaired proliferation and death of chondrocytes may be the pathological mechanism of the osteoarthropathy due to Se deficiency. Notably, this study also uncover the roles of mitochondrial ROS which could stimulate cartilage ECM synthesis that offer novel insights for development of therapeutic agent to prevent cartilage degeneration in human disease. - Highlights: • TrxR2 deficiencies enhance chondrogenic differentiation. • TrxR2 deficiencies stimulate chondrocyte proliferation. • TrxR2 deficiencies induce chondrocyte apoptosis. • TrxR2 deficiencies increase emission of mitochondrial ROS. • Mitochondrial ROS regulate chondrocyte proliferation, differentiation, and apoptosis.

60 APPLIED LIFE SCIENCES↗

Thiazolidinediones abrogate cervical cancer growth

Peroxisome proliferator-activated receptor gamma (PPAR γ) is activated by thiazolidinedione drugs (TZDs) and can promote anti-cancer properties. We used three TZDs (pioglitazone, rosiglitazone, and ciglitazone) to target cervical cancer cell lines and a nude mouse animal model. Each agent increased activation of PPAR γ, as judged by a luciferase reporter gene assay in three HPV-associated cell lines (CaSki, SiHa, and HeLa cells) while decreasing cellular proliferation in a dose-dependent manner. They also promoted Oil Red O accumulation in treated cell lines and upregulated the lipid differentiation marker adipsin. Interestingly, xenograft HeLa tumors in nude mice treated with 100 mg/kg/day pioglitazone exhibited decreased growth compared to control mice or mice treated with standard cervical chemotherapy. In conclusion, TZDs slow tumor cell growth in vitro and in vivo with decreases in cell proliferation and increases in PPAR γ and adipsin. These agents may be interesting treatments or treatment adjuncts for HPV-associated cancers or perhaps even precancerous conditions. - Highlights: • Thiazolidinediones decreases cervical cancer proliferation. • Pioglitazone increases cervical cancer differentiation. • Pioglitazone decreases tumor growth in mice. • Pioglitazone may be a useful treatment adjunct.

60 APPLIED LIFE SCIENCES↗

Protein arginine methyltransferase 1 coordinates the epithelial-mesenchymal transition/proliferation dichotomy in gastric cancer cells

Protein arginine methyltransferase 1 (PRMT1) is up-regulated and promotes migration, invasion and proliferation in wide range of cancers. However, we for the first time identify that PRMT1 promotes migration and invasion and inhibits proliferation in gastric cancer cells, a phenomenon called “migration-proliferation dichotomy”. First, we find that PRMT1 overexpression promotes migration and invasion and inhibits proliferation, whereas PRMT1 knockdown reverses the above abilities. Next, PRMT1 reduces the expression of epithelial marker E-cadherin and increases the expression of mesenchymal markers including N-cadherin, Vimentin, snail and β-catenin in gastric cancer cells. Furthermore, our studies show that PRMT1 silencing promotes the phosphorylation of LATS1, and then induces YAP phosphorylation, while overexpression of PRMT1 down-regulates the phosphorylation of LATS1 and YAP, indicating that PRMT1 inhibits EMT probably via Hippo signaling. Collectively, the present study reveals important roles of PRMT1 in progression of gastric cancer. Given the dual functions of PRMT1, it is as a potential drug target of gastric cancer with extreme caution.

60 APPLIED LIFE SCIENCES↗

MicroRNA-630 inhibits breast cancer progression by directly targeting BMI1

Highlights: • MiR-630 initiates apoptosis, blocks cell cycle progression and suppresses cell proliferation in breast cancer cells. • BMI1, a member of polycomb group family, is identified as a novel direct target of miR-630. • BMI1 mediates miR-630-suppressed breast cancer progression including apoptosis induction, cell cycle arrest, and proliferation inhibition. MicroRNAs (miRNAs) play critical roles in breast cancer cell biological processes, including proliferation and apoptosis by inhibiting the expression of their target genes. Herein, we reported that miR-630 overexpression initiates apoptosis, blocks cell cycle progression and suppresses cell proliferation in breast cancer cells. Furthermore, BMI1, a member of polycomb group family, was identified as a direct target of miR-630, and there was a negative correlation between the expression levels of BMI1 and miR-630 in human breast cancer samples. With a series of biology approaches, subsequently, we proved that BMI1 was a functional downstream target of miR-630 and mediated the property of miR-630-dependent inhibition of breast cancer progression. Taken together, these findings provide further evidence on the tumor-suppression function of miR-630 in breast cancer, and clarify BMI1 as a novel functional target gene of miR-630.

60 APPLIED LIFE SCIENCES↗

Inhibition of miR-361-5p suppressed pulmonary artery smooth muscle cell survival and migration by targeting ABCA1 and inhibiting the JAK2/STAT3 pathway

Highlights: • MiR-361-5p was significantly increased in hypoxia-induced hPASMCs. • Inhibition of miR-361-5p suppressed hypoxia-induced hPASMCs proliferation and migration. • miR-361-5p targeted ABCA1. • Overexpression of ABCA1 enhanced the effect of anti-miR-361-5p on hPASMCs proliferation and migration. • miR-361-5p inhibited JAK2/STAT3 pathway. MicroRNAs play a crucial role in the progression of pulmonary arterial hypertension (PAH). The aim of this study was to investigate the effect of miR-361-5p on the proliferation, migration and apoptosis of pulmonary artery smooth muscle cells (PASMCs) that under the treatment of hypoxia and explore the underlying mechanisms. The results proved that hypoxia noticeably up-regulated the expression of miR-361-5p in PASMCs in comparison to the normoxia-treated cells, while TNF-α and IL-6 stimulation had no obvious effects on miR-361-5p level. Hypoxia induced miR-361-5p elevation in a HIF-1α-dependent manner. Inhibition of miR-361-5p dramatically inhibited hypoxia-induced cell proliferation and migration. miR-361-5p inhibition also rescued hypoxia exposure caused suppression of PASMCs apoptosis. In addition, the results showed that ABCA1 was a direct target of miR-361-5p and was down-regulated in hypoxia-induced PASMCs. Hypoxia and TNF-α or IL-6 stimulation significantly inhibited ABCA1 expression. In addition, overexpression of ABCA1 enhanced the effect of miR-361-5p on hPASMCs. Furthermore, the inhibition of miR-361-5p significantly down-regulated the expression level of p-JAK2 and p-STAT3. In conclusion, it may suggest that the suppression of miR-361-5p suppressed PASMC survival and migration by targeting ABCA1 and inhibiting the JAK2/STAT3 pathway.

60 APPLIED LIFE SCIENCES↗

Multi-tasking Sulf1/Sulf2 enzymes do not only facilitate extracellular cell signalling but also participate in cell cycle related nuclear events

Highlights: • Dynamic SULF1/2 mobilisation to nucleus during cell cycle. • SULF1/2 co-ordinate extracellular cell signalling with nuclear role in cell cycle. • SULF1/2 overexpression increases cell proliferation while inhibition reduces growth. This study demonstrates highly dynamic spatial and temporal pattern of SULF1/SULF2 expression in a number of neuronal cell types growing in normal culture medium that included their transient nuclear mobilisation. Their nuclear translocation became particularly apparent during cell proliferation as both SULF1/SULF2 demonstrated not only cell membrane associated expression, their known site of function but also transient nuclear mobilisation during nuclear cell division. Nuclear localisation was apparent not only by immunocytochemical staining but also confirmed by immunoblotting staining of isolated nuclear fractions of C6, U87 and N2A cells. Immunocytochemical analysis demonstrated rapid nuclear exit of both SULF1/SULF2 following cell division that was slightly delayed but not blocked in a fraction of the polyploid cells observed in C6 cells. The overexpression of both Sulf1 and Sulf2 genes in C6 and U87 cells markedly promoted in vitro growth of these cells accompanied by nuclear mobilisation while inhibition of both these genes inhibited cell proliferation with little or no nuclear SULF1/SULF2 mobilisation. SULF1/SULF2 activity in these cells thus demonstrated a clear co-ordination of extracellular cell signalling with nuclear events related to cell proliferation.

60 APPLIED LIFE SCIENCES↗

Rap1b enhances the invasion and migration of hepatocellular carcinoma cells by up-regulating Twist 1

Highlights: • Rap1b was up regulated HCC tissue and HCC cells. • Rap1b promoted HCC cell proliferation in vitro and in vivo. • Upregulation of Rap1b repressed invasion and migration of hepatoma cells. • Rap1b promoted Twist 1 expression by enhancing its promoter activity. Rap1b was found be dysregulated in several types of cancers. Previously, we have demonstrated that Rap1b affects proliferation, migration and invasion of hepatocellular carcinoma (HCC) cells. However, the definite function of Rap1b in HCC remains unknown. Here, we reported that Rap1b was significantly up-regulated in HCC tissues compared with the non-tumoral liver tissues. Overexpression of Rap1b promoted tumor growth and migration in vitro and tumor formation in vivo. Oppositely, inhibition of Rap1b suppressed the proliferation and migration of HCC cells. Mechanism study revealed that Rap1b could up-regulate Twist 1 expression by enhancing its promoter activity. We concluded that Rap1b increased Twist 1 expression by targeting its promoter activity to induce proliferation and migration of HCC cells.

60 APPLIED LIFE SCIENCES↗

Long noncoding RNA SOX2OT contributes to gastric cancer progression by sponging miR-194-5p from AKT2

Highlights: • The role of SOX2/miR-194-5p/AKT2 axis in gastric cancer progression has been investigated. • SOX2OT acted as a sponge LncRNA of miR-194-5p in gastric cancer. • Suppressing SOXO2 expression can inhibit gastric cancer progression. Gastric cancer (GC) is a highly malignant cancer with poor prognosis. Long non-coding RNA (LncRNA) may play an important role in tumor progression. Our present study aimed to explore the effect of LncRNA SOX2OT on GC progression. We observed that SOX2OT was overexpressed in GC tissues and cell lines. Overexpressed SOX2OT promoted cell proliferation and metastasis of GC cells (SGC-7901, TMK-1) and the phosphorylation of AKT2 as well, while knockdown of SOX2OT reversed these effects. Besides that, miR-194-5p was predicted to be a target of SOX2OT and decreased expression of miR-194-5p was observed in GC tissues and cell lines. Overexpressed miR-194-5p counteracted the promoting role of SOX2OT on cell proliferation and invasion of GC cells. Moreover, AKT2 was predicted to be a target of miR-194-5p. The expression of AKT2 was negatively regulated by miR-194-5p while positively regulated by SOX2OT. Overexpressed AKT2 also promoted GC cell proliferation and invasion. Our in vitro experiments suggested that SOX2OT promoted cell proliferation and metastasis of GC cells via sponging miR-194-5p from AKT2. Finally, our in vivo experiments indicated that overexpressed SOX2OT promoted GC tumor growth and metastasis in nude mice. Taken together, our present study suggested that SOX2OT contributed to GC progression via sponging miR-194-5p from AKT2 both in vitro and in vivo. The SOX2OT-miR-194-5p-AKT2 axis may provide a new perspective for treatment of GC.

60 APPLIED LIFE SCIENCES↗

Combination of DESI2 and endostatin gene therapy significantly improves antitumor efficacy by accumulating DNA lesions, inducing apoptosis and inhibiting angiogenesis

Highlights: • Combination of DESI2 with endostatin could improve the therapy efficacy in vitro and in vivo. • The combination of DESI2 with endostatin causes DNA lesions accumulation. • The improved antitumor effect was associated with inhibition of cell proliferation via apoptosis. • The enhanced antitumor effect also partially resulted from inhibition of angiogenesis. DESI2 is a novel pro-apoptotic gene. We previously reported that DESI2 overexpression induces S phase arrest and apoptosis by activating checkpoint kinases. This work was to test whether the combination of endostatin, an endogenous antiangiogenic inhibitor, with DESI2 could improve the therapy efficacy in vitro and in vivo. The recombinant plasmid co-expressing DESI2 and endostatin was encapsulated with DOTAP/Cholesterol cationic liposome. Mice bearing CT26 colon carcinoma and LL2 lung cancer were treated with the DNA-liposome complex. We found that, in vitro, the combination of DESI2 and endostatin more efficiently inhibited proliferation of CT26, LL2, HCT116 and A549 cancer cells via apoptosis, as assessed by MTT assay, colony-formation assays, flow cytometric analysis, hoechst staining and activation of caspase-3, respectively. In addition, DESI2 overexpression caused up-regulation of RPS7, a substrate of DESI2 deubiquitination. Furthermore, siRNA targeting RPS7 partially abrogated, whereas RPS7 overexpression enhanced DESI2-induced inhibition of cell proliferation. Importantly, the combination also caused DNA lesions accumulation, which further promotes apoptosis. Mechanistic rationale suggested that endostatin first inhibits DNA-PKcs kinase, and partly abrogated DESI2-induced phosphorylation of DNA-PKcs, leading to increase of DNA damage, then contributes to DESI2-induced apoptosis. In vivo, the combined gene therapy more significantly inhibited tumor growth and efficiently prolonged the survival of tumor bearing mice than mono therapy. The improved antitumor effect was associated with inhibition of cell proliferation via apoptosis, as analyzed by TUNEL assay and PCNA immunostaining. The combination also inhibited angiogenesis, as assessed by alginate-encapsulated tumor cell assay and CD31 staining. Our data suggest that the combined gene therapy of DESI2 and endostatin can significantly enhance the antitumor activity as a DNA lesions accumulator, apoptosis inducer and angiogenesis inhibitor. The present study may provide a novel method for the treatment of cancer.

60 APPLIED LIFE SCIENCES↗

TMEM2 binds to CSNK2A3 to inhibit HBV infection via activation of the JAK/STAT pathway

To investigate mechanisms that TMEM2 activation inhibits hepatitis B virus (HBV) infection in hepatocarcinoma (HCC) cells, co-immunoprecipitation (Co-IP) and mass spectrometry were used in screening interacting proteins for TMEM2. Levels of casein kinase 2 subunit α3 (CSNK2A3) in HCC cells were found to be inhibited or overexpressed using siRNAs and pcDNA3.1-CSNK2A3, respectively. Effect of CSNK2A3 expression on cell proliferation was analyzed using MTS, while its effect on HBV infection was measured using ddPCR and IHC. Western blotting and JAK inhibitor ruxolitinib were also used to determine whether TMEM2-regulated CSNK2A3 expression and HBV infection were affected by JAK-STAT signaling. Co-IP and mass spectrometry results showed that CSNK2A3 interacts with TMEM2. Moreover, overexpression of CSNK2A3 significantly inhibited cell proliferation, while inhibition of CSNK2A3 promoted proliferation of HCC cells. In addition, overexpression of CSNK2A3 was observed to significantly enhance HBV infection, while siRNA knockdown of CSNK2A3 inhibited HBV infection. Notably, effect of CSNK2A3 overexpression on HBV infection was suppressed by TMEM2 overexpression. Further mechanistic analyses have revealed that TMEM2 could antagonize the effects of CSNK2A3 on cell proliferation and HBV infection via JAK-STAT pathway activation. In conclusion, TMEM2 has been determined to bind to CSNK2A3 to inhibit HBV infection via activation of the JAK-STAT pathway.

60 APPLIED LIFE SCIENCES↗

Technical Note: Impact of cell repopulation and radionuclide uptake phase on cell survival

Purpose: To study theoretically the impact on cell survival of the radionuclide uptake rate inside tumor cells for a single administration of a radiopharmaceutical. Methods: The instantaneous-uptake model of O’Donoghue [“The impact of tumor cell proliferation in radioimmunotherapy,” Cancer 73, 974–980 (1994)] for a proliferating cell population irradiated by an exponentially decreasing dose-rate is here extended to allow for the monoexponential uptake of the radiopharmaceutical by the targeted cells. The time derivative of the survival curve is studied in detail deducing an expression for the minimum of the surviving fraction and the biologically effective dose (BED). Results: Surviving fractions are calculated over a parameter range that is clinically relevant and broad enough to establish general trends. Specifically, results are presented for the therapy radionuclides Y-90, I-131, and P-32, assuming uptake half-times 1–24 h, extrapolated initial dose-rates 0.5–1 Gy h{sup −1}, and a biological clearance half-life of seven days. Representative radiobiological parameters for radiosensitive and rapidly proliferating tumor cells are used, with cell doubling time equal to 2 days and α-coefficient equal to 0.3 and 0.5 Gy{sup −1}. It is shown that neglecting the uptake phase of the radiopharmaceutical (i.e., assuming instantaneous-uptake) results in a sizeable over-estimation of cell-kill (i.e., under-estimation of cell survival) even for uptake half-times of only a few hours. The differences between the exponential-uptake model and the instantaneous-uptake model become larger for high peak dose-rates, slow uptakes, and (slightly) for long-lived radionuclides. Moreover, the sensitivity of the survival curve on the uptake model was found to be higher for the tumor cells with the larger α-coefficient. Conclusions: The exponential-uptake rate of the radiopharmaceutical inside targeted cells appears to have a considerable effect on the survival of a proliferating cell population and might need to be considered in radiobiological models of tumor cell-kill in radionuclide therapy.

60 APPLIED LIFE SCIENCES↗

Additive manufacturing: a challenge to nuclear nonproliferation

Additive manufacturing (AM) is a rapidly developing technology that allows industries to automate and simplify the production of highly complicated items. Recently, there are concerns that AM techniques have the potential to be utilized in the fields of nuclear weapons and nuclear enrichment technology. Presently, there are very few international or domestic export controls that apply to AM's role in the nuclear industry, constituting an unmanaged proliferation pathway. Pre-existing export controls focus on general concepts and processes and do not consider specific nuances of various techniques that are categorized as additive manufacturing. To introduce legislation and controls that will be effective in monitoring proliferation pathways, one must investigate and characterize AM techniques and their nuclear applications. This paper categorizes and ranks 33 AM techniques based on their potential impact on the nuclear fuel cycle and the development of nuclear weapons. Through this method of characterization and categorization, export controls would address specific AM nuclear proliferation risks without disrupting the entire industry and fuel cycle. Additionally, legislation employing this method would identify loopholes in export controls using a holistic approach to managing and monitoring proliferation pathways.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗

lncRNA-Map2k4 sequesters miR-199a to promote FGF1 expression and spinal cord neuron growth

Spinal cord injury (SCI) is a common critical illness in clinical practice. SCI prevention, treatment and rehabilitation have become important topics in today's medical profession. Studies have shown that long noncoding RNAs (lncRNAs) also play an important role in the pathology of SCI. The biology software analysis identified miR-199a binding sites in the lncRNA-Map2k4 and FGF1 sequences, which were confirmed by the subsequent dual luciferase reporter assay. When lncRNA-Map2k4 expression was down-regulated by siRNA, miR-199a expression in neurons was up-regulated and FGF1 expression was down-regulated. In turn, miR-199a up-regulation inhibited lncRNA-Map2k4 and FGF1 expression. But when lncRNA-Map2k4-m (a lncRNA-Map2k4 overexpression vector with mutated miR-199a binding sites) was co-transfected into neuronal cells with miR-199a mimics, lncRNA-Map2k4-m over-expression did not block the inhibition of FGF1 expression by miR-199a. Moreover, lncRNA-Map2k4 and FGF1 promoted the proliferation and inhibited the apoptosis of neuronal cells, whereas miR-199a down-regulated the aforementioned functions of lncRNA-Map2k4 and FGF1; however, lncRNA-Map2k4-m could not block the inhibitory action of miR-199a on proliferation. Thus, lncRNA-Map2k4 regulates neuronal proliferation and apoptosis through a miR-199a/FGF1 pathway. This finding provides more evidence for the role of lncRNAs in SCI. - Highlights: • lncRNA-Map2k4 is the target gene of miR-199a, and its down-regulation promotes miR-199a expression in neurons. • miR-199a targeted regulation of FGF1 expression in neurons. • Knockdown of lncRNA-Map2k4 inhibited the FGF1 expression by up-regulating miR-199a. • lncRNA-Map2k4 regulates neuron proliferation and apoptosis through an miR-199a/FGF1 pathway.

60 APPLIED LIFE SCIENCES↗

Decreased expression of orexin 1 receptor in adult mice testes during alloxan-induced diabetes mellitus perturbs testicular steroidogenesis and glucose homeostasis

Diabetes mellitus (DM) affects male reproductive system and causes infertility. The male reproductive health is largely dependent upon uptake and proper utilization of glucose by testicular cells. Results show involvement of orexin A (OXA) and its receptor (OX1R) in regulation of steroidogenesis and glucose homeostasis in adult mice testis. However, the role of OX1R in regulation of testicular functions during hyperglycemia has not been investigated so far. The present study, therefore, examined the role of OX1R in regulation of steroidogenesis and glucose homeostasis in testis of adult mice during alloxan-induced type 1 DM. A significant decrease was noted in body weight and testis weight in alloxan-treated mice compared to controls. The blood glucose level, however, was markedly increased in treated animals than in controls. Further, serum and intratesticular level of testosterone, activities of testicular steroidogenic enzymes, and expressions of various steroidogenic markers, OX1R, glucose transporter 3 (GLUT3) and Wilms' tumor gene (WT1) were downregulated in treated mice. The level of glucose, activity of lactate dehydrogenase (LDH) and lactate concentration in the testes of diabetic mice were also decreased; a significant increase in the number of testicular apoptotic cells with concomitant increase in the expression of caspase-3 was noted in these mice. Furthermore, DM affected germ cell proliferation with decreased expression of proliferating cell nuclear antigen (PCNA). Results thus suggest that type 1 DM impairs testicular steroidogenesis and glucose homeostasis through inhibition of OXA/OX1R signaling cascade due to decreased OX1R expression in adult mice, thereby affecting germ cell survival and their proliferation in the testis. - Highlights: • Alloxan monohydrate treatment reduces expression of testicular OX1R in adult mice. • Decreased expression of OX1R perturbs testicular steroidogenesis. • Reduced expression of OX1R affects testicular glucose homeostasis. • Impairment in OX1R expression disturbs germ cell survival and proliferation.

60 APPLIED LIFE SCIENCES↗

RACK1 promotes radiation resistance in esophageal cancer via regulating AKT pathway and Bcl-2 expression

RACK1 is a seven Trp-Asp 40 repeat protein, which interacts with a wide range of kinases and proteins. RACK1 plays an important role in the proliferation and progression of various cancers. The aim of this study is to detect the role of RACK1 in the radioresistance in esophageal cancer. The results indicated that downregulation of RACK1 reduced the colony formation ability, proliferation ability and resistance of cells to radiation effection through regulating the radiation-related proteins including pAKT, Bcl-2 and Bim; whereas upregulation of RACK1 promoted the ability and radioresistance of ESCC cells. Our findings suggest that RACK1 promotes proliferation and radioresistance in ESCC cells by activating the AKT pathway, upregulating Bcl-2 expression and downregulating protein levels of Bim. Our study fills in gaps in the field of RACK1 and radiation resistance and may provide new possibilities for improving strategies of radiotherapy in esophageal cancer. - Highlights: • RACK1 is proposed to influence the proliferation ability of cells after irradiation. • Present the relationship between RACK1 and radiation resistance of esophageal cancer. • Analyze the mechanism by which RACK1 plays a role in radiation resistance.

60 APPLIED LIFE SCIENCES↗

Secretogranin III promotes angiogenesis through MEK/ERK signaling pathway

Highlights: • Scg3 promotes endothelial proliferation, migration and tube formation. • MEK inhibitor blocks Scg3-induced angiogenesis. • ERK inhibitor suppresses Scg3-induced endothelial proliferation and migration. • MEK/ERK signaling pathway is critical to Scg3-induced angiogenesis. Secretogranin III (Scg3) was recently discovered as the first highly diabetic retinopathy-associated angiogenic factor, and its neutralizing antibody alleviated the disease with high efficacy in diabetic mice. Investigation of its molecular mechanisms will facilitate the translation of this novel therapy. Scg3 was reported to induce the phosphorylation of mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK). Here we characterized the importance of MEK/ERK activation to Scg3 angiogenic activity. Our results showed that MEK inhibitor PD98059 blocked Scg3-induced proliferation of human umbilical vein endothelial cells (HUVECs). This finding was corroborated by PD98059 inhibition of HUVEC migration and tube formation. Furthermore, ERK inhibitor SCH772984 also suppressed Scg3-induced proliferation and migration of HUVECs. Taken together, these findings suggest that MEK-ERK pathway plays an important role in Scg3-induced angiogenesis.

60 APPLIED LIFE SCIENCES↗

Long non-coding RNA THOR promotes human osteosarcoma cell growth in vitro and in vivo

Highlights: • LncRNA THOR (“Lnc-THOR”) is expressed in human osteosarcoma (OS) cells and tissues. • Lnc-THOR siRNA inhibits human OS cell survival and proliferation. • Lnc-THOR over-expression promotes human OS cell survival and proliferation. • Lnc-THOR knockout inhibits U2OS cell growth in vitro and in vivo Long non-coding RNA (LncRNA) dysregulation is associated with human osteosarcoma (OS) cell progression. Recent studies have characterized a novel but ultra-conserved LncRNA THOR (“Lnc-THOR”) as a cancer-specific LncRNA, mediating cell growth. In the current study, we show that Lnc-THOR is expressed in established and primary human OS cells. It is also detected in human OS tissues, but not in the surrounding normal bone tissues. siRNA-induced knockdown or CRSIPR/Cas9-mediated knockout Lnc-THOR significantly inhibited human OS cell survival and proliferation. Insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) target mRNAs, including IGF2, GLI1 and CD44, were downregulated in Lnc-THOR-silenced OS cells as well. Conversely, forced over-expression of Lnc-THOR enhanced IGF2BP1 target mRNA expression, promoting OS cell survival and proliferation. In vivo, xenograft tumors of Lnc-THOR-knockout U2OS cells grew significantly slower than the control U2OS tumors. Together, these results show that Lnc-THOR expression is essential for human OS cell growth. Lnc-THOR could be a novel therapeutic target and/or diagnosis marker for human OS.

60 APPLIED LIFE SCIENCES↗