Long noncoding RNA PTPRG-AS1 acts as a microRNA-194-3p sponge to regulate radiosensitivity and metastasis of nasopharyngeal carcinoma cells via PRC1

Protein regulator of cytokinesis 1 (PRC1) has been reported in correlation with various malignancies. Functionality of PRC1 in nasopharyngeal carcinoma (NPC) was investigated, in perspective of long noncoding RNA (lncRNA) regulatory circuitry. Aberrant expressed messenger RNA and lncRNA were screened out from the Gene Expression Omnibus microarray database. NPC cell line CNE-2 was adopted for in vitro study and transfected with mimic or short hairpin RNA of miR-194-3p and PTPRG-AS1. The radioactive sensitivity, cell viability, migration, invasion, and apoptosis were detected. PTPRG-AS1 and PRC1 were upregulated in NPC, whereas miR-194-3p was downregulated. PTPRG-AS1 was found to specifically bind to miR-194-3p as a competing endogenous RNA and miR-194-3p targets and negatively regulates PRC1. Overexpressed miR-194-3p or silenced PTPRG-AS1 resulted in enhanced sensitivity to radiotherapy and cell apoptosis along with suppressed cell migration, invasion and proliferation in NPC. Furthermore, impaired tumor formation was also caused by miR-194-3p overexpression or PTPRG-AS1 suppression through xenograft tumor in nude mice. In our study, PTPRG-AS1/miR-194-3p/PRC1 regulatory circuitry was revealed in NPC, the mechanism of which can be of clinical significance for treatment of NPC.     

Wnt1-inducible signaling protein 1 regulates laryngeal squamous cell carcinoma glycolysis and chemoresistance via the YAP1/TEAD1/GLUT1 pathway

Wnt1-inducible signaling protein 1 (WISP1) is a matricellular protein and downstream target of Wnt/β-catenin signaling. This study sought to determine the role of WISP1 in glucose metabolism and chemoresistance in laryngeal squamous cell carcinoma. WISP1 expression was silenced or upregulated in Hep-2 cells by the transfection of WISP1 siRNA or AdWISP1 vector. Ectopic WISP1 expression regulated glucose uptake and lactate production in Hep-2 cells. Subsequently, the expression of glucose transporter 1 (GLUT1) was significantly modulated by WISP1. Furthermore, WISP1 increased cell survival rates, diminished cell death rates, and suppressed ataxia-telangiectasia-mutated (ATM)-mediated DNA damage response pathway in cancer cells treated with cisplatin through GLUT1. WISP1 also promoted cancer cell tumorigenicity and growth in mice implanted with Hep-2 cells. Additionally, WISP1 activated the YAP1/TEAD1 pathway that consequently contributed to the regulation of GLUT1 expression. In summary, WISP1 regulated glucose metabolism and cisplatin resistance in laryngeal cancer by regulating GLUT1 expression. WISP1 may be used as a potential therapeutic target for laryngeal cancer.     

Integrative proteomics and immunochemistry analysis of the factors in the necrosis and repair in acetaminophen-induced acute liver injury in mice

Acetaminophen (APAP) overdose-induced acute liver injury (AILI) is a significant clinical problem worldwide, the hepatotoxicity mechanisms are well elucidated, but the factors involved in the necrosis and repair still remain to be investigated. APAP was injected intraperitoneally in male Institute of Cancer Research (ICR) mice. Quantitative proteome analysis of liver tissues was performed by 2-nitrobenzenesulfenyl tagging, two-dimensional-nano high-performance liquid chromatography separation, and matrix-assisted laser desorption/ionization–time of flight mass spectrometry analysis. Diffrenetial proteins were verified by the immunochemistry method. 36 and 44 differentially expressed proteins were identified, respectively, at 24 hr after APAP (200 or 300 mg·kg ⁻¹) administration. The decrease in the mitochondrial protective proteins Prdx6, Prdx3, and Aldh2 accounted for the accumulation of excessive reactive oxygen species (ROS) and aldehydes, impairing mitochondria structure and function. The Gzmf combined with Bax and Apaf-1 jointly contributed to the necrosis. The blockage of Stat3 activation led to the overexpression of unphosphorylated Stat3 and the overproduction of Bax. The overexpression of unphosphorylated Stat3 represented necrosis; the alternation from Stat3 to p-Stat3 in necrotic regions represented hepatocytes from death to renewal. The high expressions of P4hα1, Ncam, α-SMA, and Cygb were involved in the liver repair, they were not only the markers of activated HSC but also represented an intermediate stage of hepatocytes from damage or necrosis to renewal. Our data provided a comprehensive report on the profile and dynamic changes of the liver proteins in AILI; the involvement of Gzmf and the role of Stat3 in necrosis were revealed; and the role of hepatocyte in liver self-repair was well clarified.     

In vivo surveillance and elimination of teratoma-forming human embryonic stem cells with monoclonal antibody 2448 targeting annexin A2

This study describes the use of a previously reported chimerised monoclonal antibody (mAb), ch2448, to kill human embryonic stem cells (hESCs) in vivo and prevent or delay the formation of teratomas. ch2448 was raised against hESCs and was previously shown to effectively kill ovarian and breast cancer cells in vitro and in vivo. The antigen target was subsequently found to be Annexin A2, an oncofetal antigen expressed on both embryonic cells and cancer cells. Against cancer cells, ch2448 binds and kills via antibody-dependent cell-mediated cytotoxicity (ADCC) and/or antibody-drug conjugate (ADC) routes. Here, we investigate if the use of ch2448 can be extended to hESC. ch2448 was found to bind specifically to undifferentiated hESC but not differentiated progenitors. Similar to previous study using cancer cells, ch2448 kills hESC in vivo either indirectly by eliciting ADCC or directly as an ADC. The treatment with ch2448 post-transplantation eliminated the in vivo circulating undifferentiated cells and prevented or delayed the formation of teratomas. This surveillance role of ch2448 adds an additional layer of safeguard to enhance the safety and efficacious use of pluripotent stem cell-derived products in regenerative medicine. Thereby, translating the use of ch2448 in the treatment of cancers to a proof of concept study in hESC (or pluripotent stem cell [PSC]), we show that mAbs can also be used to eliminate teratoma forming cells in vivo during PSC-derived cell therapies. We propose to use this strategy to complement existing methods to eliminate teratoma-forming cells in vitro. Residual undifferentiated cells may escape in vitro removal methods and be introduced into patients together with the differentiated cells.     

Extracellular αB-crystallin modulates the inflammatory responses

Neuroinflammation is considered a challenging clinical problem. Chronic inflammatory responses play important roles in the onset and progression of various neurodegenerative diseases, including multiple sclerosis (MS). Previous studies have shown that astrocytes express small heat shock protein αB-crystallin (CRYAB) which is capable of inhibiting inflammatory responses in astrocytes per se. However, the underlying mechanisms of CRYAB-induced modulation of neuroinflammation are still not fully understood. In the present study, we investigated the role of extracellular CRYAB in the interaction between microglia and astrocytes in the context of MS-associated neuroinflammation. We found that the expression of CRYAB was profoundly increased in EAE mice. CRYAB was preferentially expressed in astrocytes and could be secreted via exosomes. Levels of exosomal CRYAB secreted from astrocytes were markedly increased under stress conditions. Furthermore, incubation of immortalized astrocytes or microglia cell lines with CRYAB remarkably suppressed astrocytes and microglia-mediated inflammatory responses in both autocrine and paracrine manners. Our results reveal a novel function for extracellular CRYAB in the regulation of neuroinflammation. Targeting extracellular CRYAB-modulated neuroinflammation is a potential therapeutic intervention for MS.     

Dynamics of Membrane-Bound G12V-KRAS from Simulations and Single-Molecule FRET in Native Nanodiscs

Recent studies have shown that the small GTPase KRAS adopts multiple orientations with respect to the plane of anionic model membranes, whereby either the three C-terminal helices or the three N-terminal β-strands of the catalytic domain face the membrane. This has functional implications because, in the latter, the membrane occludes the effector-interacting surface. However, it remained unclear how membrane reorientation occurs and, critically, whether it occurs in the cell in which KRAS operates as a molecular switch in signaling pathways. Herein, using data from a 20 μs-long atomistic molecular dynamics simulation of the oncogenic G12V-KRAS mutant in a phosphatidylcholine/phosphatidylserine bilayer, we first show that internal conformational fluctuations of flexible regions in KRAS result in three distinct membrane orientations. We then show, using single-molecule fluorescence resonance energy transfer measurements in native lipid nanodiscs derived from baby hamster kidney cells, that G12V-KRAS samples three conformational states that correspond to the predicted orientations. The combined results suggest that relatively small energy barriers separate orientation states and that signaling-competent conformations dominate the overall population.