Knockdown of SLC34A2 inhibits cell proliferation,metastasis, and elevates chemosensitivity in glioma

Solute carrier 34 A2 (SLC34A2) is a member of SLC34 family that is a group of phosphate transporters. SLC34A2 has been reported to play critical roles in tumorigenesis and progression. However, the researches about the biological roles of SLC34A2 in glioma have not yet been reported. In this study, we analyzed the expression patterns of SLC34A2 in clinical glioma tumor tissues and cell lines. The results demonstrated that SLC34A2 was generally overexpressed in both glioma tissues and cell lines. To further investigate the roles of SLC34A2 in glioma, lentivirus containing specific SLC34A2 short hairpin RNA (sh-SLC34A2) was used to infect glioma cell lines U251 and U87 for the knockdown of SLC34A2. The following studies proved that SLC34A2 knockdown exhibited suppressive effects on cell proliferation and migration/invasion. SLC34A2 knockdown also inhibited epithelial-mesenchymal transition (EMT) phenotype, as evidenced by the increased E-cadherin expression, and the decreased N-cadherin and fibronectin expressions. Besides, knockdown of SLC34A2 enhanced the temozolomide (TMZ) sensitivity of U251 and U87 cells. In vivo tumorigenicity assay demonstrated that SLC34A2 knockdown inhibited tumor growth. Moreover, SLC34A2 knockdown suppressed the activation of epidermal growth factor receptor (EGFR)/PI3K/AKT signaling pathway in U87 cells. GW2974 (EGFR inhibitor) increased SLC34A2 knockdown-inhibited cell proliferation, migration/invasion, as well as enhanced SLC34A2 knockdown-increased the TMZ sensitivity of glioma cells. These findings suggested that SLC34A2 might be a new potential therapeutic target for the therapy of glioma patients.     

Interleukin‐37 improves T‐cell‐mediated immunity and chimeric antigen receptor T‐cell therapy in aged backgrounds

Aging‐associated declines in innate and adaptive immune responses are well documented and pose a risk for the growing aging population, which is predicted to comprise greater than 40 percent of the world''s population by 2050. Efforts have been made to improve immunity in aged populations; however, safe and effective protocols to accomplish this goal have not been universally established. Aging‐associated chronic inflammation is postulated to compromise immunity in aged mice and humans. Interleukin‐37 (IL‐37) is a potent anti‐inflammatory cytokine, and we present data demonstrating that IL‐37 gene expression levels in human monocytes significantly decline with age. Furthermore, we demonstrate that transgenic expression of interleukin‐37 (IL‐37) in aged mice reduces or prevents aging‐associated chronic inflammation, splenomegaly, and accumulation of myeloid cells (macrophages and dendritic cells) in the bone marrow and spleen. Additionally, we show that IL‐37 expression decreases the surface expression of programmed cell death protein 1 (PD‐1) and augments cytokine production from aged T‐cells. Improved T‐cell function coincided with a youthful restoration of Pdcd1, Lat, and Stat4 gene expression levels in CD4⁺ T‐cells and Lat in CD8⁺ T‐cells when aged mice were treated with recombinant IL‐37 (rIL‐37) but not control immunoglobin (Control Ig). Importantly, IL‐37‐mediated rejuvenation of aged endogenous T‐cells was also observed in aged chimeric antigen receptor (CAR) T‐cells, where improved function significantly extended the survival of mice transplanted with leukemia cells. Collectively, these data demonstrate the potency of IL‐37 in boosting the function of aged T‐cells and highlight its therapeutic potential to overcome aging‐associated immunosenescence.     

Inhibition of fatty acid synthase suppresses U-2 OS cell invasion and migration via downregulating the activity of HER2/PI3K/AKT signaling pathway in vitro

FASN plays an important role in the malignant phenotype of various tumors. Our previous studies show that inhibition FASN could induce apoptosis and inhibit proliferation in human osteosarcoma (OS) cell in vivo and vitro. The aim in this study was to investigate the effect of inhibition FASN on the activity of HER2/PI3K/AKT axis and invasion and migration of OS cell. The expression of FASN, HER2 and p-HER2(Y1248) proteins was detected by immunohistochemistry in OS tissues from 24 patients with pulmonary metastatic disease, and the relationship between FASN and p-HER2 as well as HER2 was investigated. The results showed that there was a positive correlation between FASN and HER2 as well as p-HER2 protein expression. The U-2 OS cells were transfected with either the FASN specific RNAi plasmid or the negative control RNAi plasmid. FASN mRNA was measured by RT-PCR. Western blot assays was performed to examine the protein expression of FASN, HER2, p-HER2(Y1248), PI3K, Akt and p-Akt (Ser473). Migration and invasion of cells were investigated by wound healing and transwell invasion assays. The results showed that the activity of HER2/PI3K/AKT signaling pathway was suppressed by inhibiting FASN. Meanwhile, the U-2OS cells migration and invasion were also impaired by inhibiting the activity of FASN/HER2/PI3K/AKT. Our results indicated that inhibition of FASN suppresses OS cell invasion and migration via down-regulation of the “HER2/PI3K/AKT” axis in vitro. FASN blocker may be a new therapeutic strategy in OS management.     

Function of RNA-binding protein Musashi-1 in stem cells

Musashi is an evolutionarily conserved family of RNA-binding proteins that is preferentially expressed in the nervous system. The first member of the Musashi family was identified in Drosophila. This protein plays an essential role in regulating the asymmetric cell division of ectodermal precursor cells known as sensory organ precursor cells through the translational regulation of target mRNA. In the CNS of Drosophila larvae, however, Musashi is expressed in proliferating neuroblasts and likely has a different function. Its probable mammalian homologue, Musashi-1, is a neural RNA-binding protein that is strongly expressed in fetal and adult neural stem cells (NSCs). Mammalian Musashi-1 augments Notch signaling through the translational repression of its target mRNA, m-Numb, thereby contributing to the self-renewal of NSCs. In addition to its functions in NSCs, the role of mammalian Musashi-1 protein in epithelial stem cells, including intestinal and mammary gland stem cells, is attracting increasing interest.     

Distribution of purinergic P2X receptors in the equine digit, cervical spinal cord and dorsal root ganglia

Purinergic pathways are considered important in pain transmission, and P2X receptors are a key part of this system which has received little attention in the horse. The aim of this study was to identify and characterise the distribution of P2X receptor subtypes in the equine digit and associated vasculature and nervous tissue, including peripheral nerves, dorsal root ganglia and cervical spinal cord, using PCR, Western blot analysis and immunohistochemistry. mRNA signal for most of the tested P2X receptor subunits (P2X_{1–5, 7}) was detected in all sampled equine tissues, whereas P2X₆ receptor subunit was predominantly expressed in the dorsal root ganglia and spinal cord. Western blot analysis validated the specificity of P2X_{1–3, 7} antibodies, and these were used in immunohistochemistry studies. P2X_{1–3, 7} receptor subunits were found in smooth muscle cells in the palmar digital artery and vein with the exception of the P2X₃ subunit that was present only in the vein. However, endothelial cells in the palmar digital artery and vein were positive only for P2X₂ and P2X₃ receptor subunits. Neurons and nerve fibres in the peripheral and central nervous system were positive for P2X_1–3 receptor subunits, whereas glial cells were positive for P2X₇ and P2X_{1 and 2} receptor subunits. This previously unreported distribution of P2X subtypes may suggest important tissue specific roles in physiological and pathological processes.     

CK2 signaling in androgen-dependent and -independent prostate cancer

Protein serine/threonine kinase casein kinase 2 (CK2) is a key player in cell growth and proliferation but is also a potent suppressor of apoptosis. CK2 has been found to be dysregulated in all the cancers that have been examined, including prostate cancer. Investigations of CK2 signaling in the prostate were originally initiated in this laboratory, and these studies have identified significant functional activities of CK2 in relation to normal prostate growth and to the pathobiology of androgen-dependent and -independent prostate cancer. We present a brief overview of these developments in the context of prostate biology. An important outcome of these studies is the emerging concept that CK2 can be effectively targeted for cancer therapy.     

Conservation of key members in the course of the evolution of the insulin signaling pathway

Our understanding of the evolution of the insulin signaling pathway (ISP) is still incomplete. One intriguing unanswered question is the explanation of the emergence of the glucostatic role of insulin in mammals. To find out whether this is due to the development of new sets of signaling transduction elements in these organisms, or to the establishment of new interactions between pre-existing proteins, we rebuilt putative orthologous ISPs in 17 eukaryotic organisms. Then, we computed the conservation of orthologous ISPs at different levels, from sequence similarity of orthologous proteins to co-evolution of interacting domains. We found that the emergence of glucostatic role in mammals can neither be explained by the development of new sets of signaling elements, nor by the establishment of new interactions between pre-existing proteins. The comparison of orthologous IRS molecules indicates that only in mammals have they acquired their complete functionality as efficient recruiters of effector sub-pathways.     

PLS3 predicts poor prognosis in pancreatic cancer and promotes cancer cell proliferation via PI3K/AKT signaling

Plastin-3 plays a key role in cancer cell proliferation and invasion, but its prognostic value in pancreatic cancer (PACA) remains poorly defined. In this study, we show that PLS3 messenger RNA is overexpressed in PACA tissue compared with normal tissue. We accumulated 207 cases of PACA specimens to perform immunohistochemical analysis and demonstrated that PLS3 levels correlate with T-classification (p < .001) and pathology (p < .001). Furthermore, overall survival rates (p < .001) in tumors with high PLS3 expression were poor, as assessed through Kaplan–Meier survival analysis. PLS3 was found to be an independent prognostic factor for PACA through multivariate Cox regression analysis. Moreover, we found that PLS3 enhances the proliferation and invasion of tumor cells as assessed through Cell Counting Kit-8, wounding healing assays, and Transwell assays. The upregulation of PLS3 also led to enhanced phosphatidylinositol-3 kinase/protein kinase B signaling in PACA cells. These data suggest that PLS3 is a biomarker to estimate PACA progression and represents a molecular target for PACA therapy.     

Platycodin D protects cortical neurons against oxygen-glucose deprivation/reperfusion in neonatal hypoxic-ischemic encephalopathy

Neonatal hypoxic-ischemic encephalopathy is one of the leading causes of death in infants. Increasing evidence indicates that oxidative stress and apoptosis are major contributors to hypoxic-ischemic injury and can be used as particularly promising therapeutic targets. Platycodin D (PLD) is a triterpenoid saponin that exhibits antioxidant properties. The aim of this study was to evaluate the effects of PLD on hypoxic-ischemic injury in primary cortical neurons. We found that oxygen-glucose deprivation/reperfusion (OGD/R) induced inhibition of cell viability and cytotoxicity, which were attenuated by PLD treatment. PLD treatment inhibited oxidative stress induced by OGD/R, which was evidenced by the reduced level of reactive oxygen species and increased activities of catalase, superoxide dismutase, and glutathione peroxidase. Histone-DNA enzyme-linked immunosorbent assay revealed that apoptosis was significantly decreased after PLD treatment in OGD/R-treated cortical neurons. The increased bax expression and decreased bcl-2 expression induced by OGD/R were reversed by PLD treatment. Furthermore, PLD treatment caused the activation of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway in OGD/R-stimulated cortical neurons. Suppression of this pathway blocked the protective effects of PLD on OGD/R-induced cell injury. These findings suggested that PLD executes its protective effects on OGD/R-induced cell injury via regulating the PI3K/Akt/mTOR pathway in cortical neurons.