OBJECTIVETo search for a new diagnostic biomarker for prostate cancer by comparing the differences in the expressions of netrin-1 and UNC5B in prostate cancer cells with different invasive abilities.

METHODSWe examined the expressions of netrin-1 and UNC5B in five prostate cancer cell lines DU145, 22RV1, PC3, PC3M and RWPE-1 using RT-PCR and Western blot, and positioned the ligands netrin-1 and its receptor UNC5B in the prostate cancer cells by immunofluorescence.

RESULTSBoth netrin-1 and UNC5B were expressed in the prostate cancer cells, and the expression of netrin-1 was significantly increased in highly invasive cells (P < 0.05), while that of UNC5B in RWPE-1 (normal) cells (P < 0.05).

CONCLUSIONThe expressions of netrin-1 and UNC5B are closely related to the infiltration and progression of prostate cancer, and expected to be as potential biomarkers for predicting the malignancy degree of prostate cancer.

Biomarkers, Tumor ; metabolism ; Cell Line, Tumor ; Humans ; Male ; Nerve Growth Factors ; metabolism ; Netrin-1 ; Prostatic Neoplasms ; metabolism ; pathology ; Receptors, Cell Surface ; metabolism ; Tumor Suppressor Proteins ; metabolism

UNLABELLED: AbstractObjective: To investigate the effect of the axon guidance factor Netrin-1 on the expression of VEGFA in T cell acute lymphoblastic leukemia(T-ALL) and its related mechanism. METHODS: ELISA assays were applied to detect the levels of Netrin-1 and VEGFA in the bone marrow (BM) samples from children in the T-ALL and control group. The level of Netrin-1 and VEGFA were compared between control children and patients, and the liner correlation between Netrin-1 and VEGFA was analyzed. The T-ALL cells Jurkat and Molt-4 were culture in vitro, and the cells were treated with different concentration of Netrin-1 (0, 25, 50, 100 ng/ml) for 24 h, quantitative RT-PCR (qRT-PCR) and Western blot were used to detect the VEGFA expression in Jurkat, Molt-4 cells. The expression of Netrin-1 receptors in T-ALL cells was detected by qRT-PCR and the interaction between Netrin-1 and receptor in each cells was detected by co-IP. Furthermore, Western blot was used to detect the phosphorylation level of key prateins of AKT signal transduction pathway including Akt and mTOR in T-ALL cells treated with Netrin-1 (100 ng/ml). The expression of VEGFA and phosphorylation of AKT pathway transducers were detected by Western blot, after T-ALL cells treated with Netrin-1 (100 ng/ml) combined with inhibitors specific to Akt or mTOR. RESULTS: The expression level of Netrin-1 and VEGFA in T-ALL patients BM samples were both signi-ficantly higher than that of control group. And the expression level of Netrin-1 was positively correlated with that of VEGFA（r2=0974). With the increase of Netrin-1 concentration, the expression level of VEGFA also increased(P<0.05）. Netrin-1 interacted with its receptor, integrin-β4 at the Netrin-1 concentration of 100 ng/ml. Further, the treatment of Netrin-1 could increase the phosphorylation of Akt and mTOR, which were the key transducers of AKT pathway. After treatment of T-ALL cells with Netrin-1 (100 ng/mL) and Akt inhibitor, the expression of VEGFA and phosphorylation of Akt or mTOR decreased. When the cells were treated with Netrin-1(100 ng/ml) and mTOR inbititor, the phosphorylation level of mTOR and the expression of VEGFA decreased, the phosphorylation level of Akt increased. CONCLUSION The expression of Netrin-1 and VEGFA in bone marrow of childred with T-ALL were abnormal, and there was a linear relationship between them. Netrin-1 can interact with its receptor, integrin-β4 and activate AKT transduction pathway to elevate the expression of VEGFA in T-ALL cells.
Child ; Humans ; Integrins ; Netrin-1/metabolism* ; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma ; Proto-Oncogene Proteins c-akt/metabolism* ; T-Lymphocytes ; TOR Serine-Threonine Kinases/metabolism* ; Vascular Endothelial Growth Factor A

OBJECTIVETo observe the expression and distribution of adult rat axon guidance cues Netrin-1 and Slit2 at different time points after spinal cord injury and to investigate the guidance mechanism of regenerated axons.

METHODSTwenty adult Sprague Dawley (SD) rats were divided randomly into five groups with 4 in each. Four groups of them were used to make Allen's spinal cord punch models and we took materials randomly from one of them on the 2nd, 4th, 7th and 14th day respectively after operation. The left one group was taken as the control group. Immunofluorescence laser confocal scan was used to examine the co-expression and localization of Netrin-1 and Slit2 proteins in the injured site of the spinal cord.

RESULTSWithin two weeks after SCI, the expression of Netrin-1 and Slit2 proteins increased temporarily and there was co-expression of them on the neuron plasma membrane.

CONCLUSIONSSynchronous high expression and co-expression of axon attractant Netrin-1 and repellent Slit2 are found in the adult rat injured spinal cord in the damaged local and vicinity parts, and probably, they act as the key regulators of axon guidance regeneration.

Animals ; Female ; Intercellular Signaling Peptides and Proteins ; analysis ; Male ; Microscopy, Confocal ; Nerve Growth Factors ; analysis ; Nerve Regeneration ; physiology ; Nerve Tissue Proteins ; analysis ; Netrin-1 ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Spinal Cord Injuries ; metabolism ; Tumor Suppressor Proteins ; analysis

Down syndrome cell adhesion molecule (DSCAM) acts as a netrin-1 receptor and mediates attractive response of axons to netrin-1 in neural development. However, the signaling mechanisms of netrin-DSCAM remain unclear. Here we report that AMP-activated protein kinase (AMPK) interacts with DSCAM through its γ subunit, but does not interact with DCC (deleted in colorectal cancer), another major receptor for netrin-1. Netrin-treatment of cultured cortical neurons leads to increased phosphorylation of AMPK. Both AMPK mutant with dominant-negative effect and AMPK inhibitor can significantly suppress netrin-1 induced neurite outgrowth. Together, these findings demonstrate that AMPK interacts with DSCAM and plays an important role in netrin-1 induced neurite outgrowth. Our study uncovers a previously unknown component, AMPK, in netrin-DSCAM signaling pathway.
AMP-Activated Protein Kinases ; antagonists & inhibitors ; genetics ; metabolism ; Animals ; Cell Adhesion Molecules ; genetics ; metabolism ; Cells, Cultured ; HEK293 Cells ; Humans ; Mice ; Nerve Growth Factors ; pharmacology ; Netrin-1 ; Neurites ; physiology ; Neurons ; cytology ; drug effects ; metabolism ; Phosphorylation ; Protein Binding ; Protein Kinase Inhibitors ; pharmacology ; RNA Interference ; RNA, Small Interfering ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Signal Transduction ; drug effects ; Transfection ; Tumor Suppressor Proteins ; pharmacology