Circ_0000620 acts as an oncogenic factor in gastric cancer through regulating MMP2 expression via sponging miR-671-5p

Background Gastric cancer (GC) is one of the most common cancers in the digestive system. Circular RNAs (circRNAs) have been found to function as important regulators in the pathogenesis of GC. This study focused on the biological role and molecular mechanism of circ_0000620 in GC progression. Methods The expression levels of circ_0000620, microRNA-671-5p (miR-671-5p) and Matrix MetalloProteinase 2 (MMP2) were measured by quantitative real-time polymerase chain reaction (qRT-PCR), immunohistochemistry (IHC) assay or western blot. The stability of circ_0000620 was confirmed by Ribonuclease R (RNase R) assay. The protein levels were determined by western blot assay. Cell viability, colony formation, cell migratory ability, cell invasive ability and tube formation capacity were respectively examined by CCK-8 assay, colony formation assay, wound healing assay, transwell invasion assay and tube formation assay. The interaction between miR-671-5p and circ_0000620 or MMP2 was validated by dual-luciferase reporter assay, RNA immunoprecipitation (RIP) assay and RNA pull-down assay. The role of circ_0000620 in GC undefined was explored by xenograft tumor assay. Results Circ_0000620 was conspicuously upregulated in GC tissues and cells. Circ_0000620 knockdown reduced cell viability, colony formation, migration, invasion and tube formation capacity of GC cells in vitro. Furthermore, MMP2 was upregulated in GC and MMP2 overexpression reversed the anti-tumor response of circ_0000620 knockdown in GC progression. Moreover, circ_0000620 directly interacted with miR-671-5p and circ_0000620 downregulation regulated malignant behaviors of GC cells by upregulating miR-671-5p. In addition, silencing of circ_0000620 inhibited tumor growth in vivo. Conclusions Circ_0000620 knockdown inhibited the malignant development of GC partly through modulating the miR-671-5p/MMP2 axis.

Peroxiredoxin-6 regulates p38-mediated epithelial–mesenchymal transition in HCT116 colon cancer cells

Background Peroxiredoxins (Prxs) are antioxidant enzymes that protect cells from oxidative stress induced by several factors. They regulate several signaling pathways, such as metabolism, immune response, and intracellular reactive oxygen species (ROS) homeostasis. Epithelial–mesenchymal transition (EMT) is a transforming process that induces the loss of epithelial features of cancer cells and the gain of the mesenchymal phenotype. The EMT promotes metastasis and cancer cell progression mediated by several pathways, such as mitogen-activated protein kinases (MAPKs) and epigenetic regulators. Methods We used Prx6 overexpressed and downregulated HCT116 cells to study the mechanism between Prx6 and colon cancer. The expression of Prx6, GAPDH, Snail, Twist1, E-cadherin, Vimentin, N-cadherin, ERK, p-ERK, p38, p-p38, JNK, and p-JNK were detected by Western blotting. Additionally, an animal study for xenograft assay was conducted to explore the function of Prx6 on tumorigenesis. Cell proliferation and migration were determined by IncuCyte Cell Proliferation and colony formation assays. Results We confirmed that the expression of Prx6 and EMT signaling highly occurs in HCT116 compared with that in other colon cancer cell lines. Prx6 regulates the EMT signaling pathway by modulating EMT-related transcriptional repressors and mesenchymal genes in HCT116 colon cancer cells. Under the Prx6-overexpressed condition, HCT116 cells proliferation increased significantly. Moreover, the HCT116 cells proliferation decreased in the siPrx6-treated cells. Eleven days after HCT116 cell injection, Prx6 was overexpressed in the HCT116-injected mice, and the tumor volume increased significantly compared with that of the control mice. Furthermore, Prx6 regulates EMT signaling through p38 phosphorylation in colon cancer cells. Conclusion We suggested that Prx6 regulates EMT signaling pathway through p38 phosphorylation modulation in HCT116 colon cancer cells.

Nesfatin-1 protects H9c2 cardiomyocytes against cobalt chloride-induced hypoxic injury by modulating the MAPK and Notch1 signaling pathways

Background This study aimed to explore the effect of nesfatin-1 on cobalt chloride (CoCl2)-induced hypoxic injury in cardiomyocyte H9c2 cells. Methods H9c2 cardiomyocytes were induced by different concentrations of CoCl2 to mimic the hypoxia condition. Cell viability was detected by MTT assay. Cell apoptosis was detected by TUNEL staining and flow cytometry. ROS production was detected using the fluorescence probe DCFH-DA. The mitochondrial membrane potential (MMP) was detected using the TMRE method. The levels of released lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), and catalase (CAT) were detected using the commercial kits. The protein levels of MAPK signaling members (p-JNK1/2, p-ERK1/2, and p-p38) and Notch1 signaling members (Notch1, Hes 1, and Jagged 1) were detected by Western blot. Results CoCl2 significantly promoted cell apoptosis, increased LDH leakage, MDA concentration, and decreased cell viability, SOD activity, GSH production, and CAT activity. CoCl2-induced hypoxic injury in H9c2 cells was partially restored by nesfatin-1 treatment. Moreover, nesfatin-1 treatment attenuated CoCl2-induced increase in ROS production and mitochondrial dysfunction, decreased mitochondrial membrane potential, Bax/Bcl-2 imbalance, as well as c-caspase-9 and c-caspase-3 levels. Moreover, nesfatin-1 treatment inhibited the activation of MAPK and Notch1 signaling pathways. Conclusions Nesfatin-1 could effectively protect H9c2 cells against CoCl2-induced hypoxic injury by blocking MAPK and Notch1 signaling pathways, suggesting that nesfatin-1 might be a promising therapeutic agent for hypoxic cardiac injury.

LncRNA FBXL19-AS1 promotes proliferation and metastasis of cervical cancer through upregulating COL1A1 as a sponge of miR-193a-5p

Background Cervical cancer (CC) is one of the most common and malignant tumors in women. In this study, we aim to explore the role and mechanism of F-box and leucine rich repeat protein 19 antisense RNA 1 (FBXL19-AS1), a novel long-chain non coding RNA (lncRNA) with marked roles in a variety of tumors, in regulating the proliferation and metastasis of CC. Methods The expression of FBXL19-AS1, miR-193a-5p and COL1A1 were detected by RT-PCR and western blot. Gain- and loss-of functional assays of FBXL19-AS1 and miR-193a-5p were performed in CC cell lines in vitro or in vivo. The proliferation, migration, invasion, apoptosis and epithelial-mesenchymal transition (EMT) of CC cells were determined. Results FBXL19-AS1 and COL1A1 were significantly up-regulated in CC tissues, while miR-193a-5p was significantly down-regulated. Overexpression of FBXL19-AS1 significantly promoted the proliferation, migration, invasion, EMT and growth of CC cells and inhibited apoptosis, while knockdown of FBXL19-AS1 had the opposite effects. On the other hand, miR-193a-5p inhibited the proliferation and metastasis of CC cells. Mechanistically, FBXL19-AS1 functioned as a competitive endogenous RNA (ceRNA) and inhibited the expression of miR-193a-5p, which targeted at the 3’-UTR site of COL1A1 and negatively regulated COL1A1 expression. Conclusions FBXL19-AS1 promotes the proliferation and metastasis of CC cells by sponging miR-193a-5p and up-regulating COL1A1.

CircCNIH4 inhibits gastric cancer progression via regulating DKK2 and FRZB expression and Wnt/β-catenin pathway

Background Circular RNAs (circRNAs) have been reported to play an important role in tumor progression in various cancer types, including gastric cancer. The aim of this study was to investigate the role of circCNIH4 (hsa_circ_0000190) in gastric cancer and the underlying mechanism. Methods The expression levels of circCNIH4 and Wnt antagonist genes were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The protein levels of β-catenin, Ki67, Dickkopf 2 (DKK2) and Frizzled related protein (FRZB) were measured by western blot. Ectopic overexpression or knockdown of circCNIH4, proliferation, apoptosis, migration and invasion by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT), flow cytometry and transwell assay in vitro, and in vivo experiment, were employed to assess the role of circCNIH4 in gastric cancer. Results CircCNIH4 was downregulated in gastric cancer tissues and cells. Overexpression of circCNIH4 inhibited gastric cancer cell proliferation, migration and invasion and promoted apoptosis by inactivating Wnt/β-catenin pathway in vitro. CircCNIH4 induced the expression of DKK2 and FRZB in gastric cancer cells. Moreover, silencing of DKK2 or FRZB reversed circCNIH4 overexpression-mediated effects on gastric cancer cells. Additionally, circCNIH4 suppressed tumor growth via regulating DKK2 and FRZB expression in gastric cancer in vivo. Conclusion Our study demonstrated that circCNIH4 played a tumor-inhibiting role through upregulating DKK2 and FRZB expression and suppressing Wnt/β-catenin pathway in gastric cancer, which might provide a potential biomarker for the diagnosis and treatment of gastric cancer.

Predicted antiviral drugs Darunavir, Amprenavir, Rimantadine and Saquinavir can potentially bind to neutralize SARS-CoV-2 conserved proteins

Background Novel Coronavirus disease 2019 or COVID-19 has become a threat to human society due to fast spreading and increasing mortality. It uses vertebrate hosts and presently deploys humans. Life cycle and pathogenicity of SARS-CoV-2 have already been deciphered and possible drug target trials are on the way. Results The present study was aimed to analyze Non-Structural Proteins that include conserved enzymes of SARS-CoV-2 like papain-like protease, main protease, Replicase, RNA-dependent RNA polymerase, methyltransferase, helicase, exoribonuclease and endoribonucleaseas targets to all known drugs. A bioinformatic based web server Drug ReposeER predicted several drug binding motifs in these analyzed proteins. Results revealed that anti-viral drugs Darunavir,Amprenavir, Rimantadine and Saquinavir were the most potent to have 3D-drug binding motifs that were closely associated with the active sites of the SARS-CoV-2 enzymes . Conclusions Repurposing of the antiviral drugs Darunavir, Amprenavir, Rimantadine and Saquinavir to treat COVID-19 patients could be useful that can potentially prevent human mortality. Graphic abstract

Callose: a multifunctional (1, 3)-β–d-glucan involved in morphogenesis and function of angiosperm stomata

Background Although the cellulose microfibril organization in guard cell (GC) walls play a crucial role in the mechanism of the stomatal function, recent work showed that matrix cell wall materials are also involved. Especially in the kidney-shaped stomata of the fern Asplenium nidus, callose actively participates in the mechanism of opening and closure of the stomatal pore. Scope The present review briefly presents and discusses recent findings concerning the distribution and role of callose in the kidney-shaped stomata of the dicotyledon Vigna sinensis as well as in the dumbbell-shaped stomata of the monocotyledon Zea mays. Conclusion The discussed data support that, in both categories of angiosperm stomata, callose is implicated in the mechanism of stomatal pore formation and stomata function by locally affecting the mechanical properties of the GC cell walls.

PTD-mediated delivery of α-globin chain into Κ-562 erythroleukemia cells and α-thalassemic (HBH) patients’ RBCs ex vivo in the frame of Protein Replacement Therapy

Background α-Thalassemia, a congenital hemoglobinopathy, is characterized by deficiency and/or reduced levels of α-globin chains in serious forms of α-thalassemia (HbH disease/Hb Bart’s). This research work deals with a Protein Replacement Therapy approach in order to manage α-thalassemia manifestations, caused by the excess of β-globin chain into HbH RBCs. The main goal was to produce the recombinant human α-globin chain in fusion with TAT, a Protein Transduction Domain, to ex vivo deliver it into HbH patients RBCs, to replace the endogenous missing α-globin chain. Results Cloning of the α-globin coding sequence, fused to the nucleotide sequence of TAT peptide was conducted and the human recombinant fusion proteins, 10xHis-XaSITE-α-globin-HA and 10xHis-XaSITE-TAT-α-globin-HA were produced. The ability of human recombinant 10xHis-XaSITE-α-globin-HA to interact in vitro with the previously produced 10xHis-XaSITE-TAT-β-globin-HA and form α-/β-globin heterodimers, was assessed and confirmed by size exclusion chromatography. The recombinant 10xHis-XaSITE-TAT-α-globin-HA was successfully delivered into human proerythroid K-562 cells, during the preliminary transduction evaluation experiments. Finally, the recombinant, TAT-fused α-globin was successfully transduced into RBCs, derived from HbH patients and reduced the formation of HbH-Inclusion Bodies, known to contain harmful β4-globin chain tetramers. Conclusions Our data confirm the successful ex vivo transduction of recombinant α-globin chains in HbH RBCs to replace the missing a-globin chain and reduce the HbH-inclusion bodies, seen in α-thalassemias. These findings broaden the possibility of applying a Protein Replacement Therapy approach to module sever forms of α-thalassemia, using recombinant α-globin chains, through PTD technology.

Relationship between the structure and function of the transcriptional regulator E2A

E proteins are transcriptional regulators that regulate many developmental processes in animals and lymphocytosis and leukemia in Homo sapiens. In particular, E2A, a member of the E protein family, plays a major role in the transcriptional regulatory network that promotes the differentiation and development of B and T lymphocytes. E2A-mediated transcriptional regulation usually requires the formation of E2A dimers, which then bind to coregulators. In this review, we summarize the mechanisms by which E2A participates in transcriptional regulation from a structural perspective. More specifically, the C-terminal helix-loop-helix (HLH) region of the basic HLH (bHLH) domain first dimerizes, and then the activation domains of E2A bind to different coactivators or corepressors in different cell contexts, resulting in histone acetylation or deacetylation, respectively. Then, the N-terminal basic region (b) of the bHLH domain binds to or dissociates from a specific DNA motif (E-box sequence). Last, trans-activation or trans-repression occurs. We also summarize the properties of these E2A domains and their interactions with the domains of other proteins. The feasibility of developing drugs based on these domains is discussed.

Sevoflurane inhibits malignant progression of colorectal cancer via hsa_circ_0000231-mediated miR-622

Background Sevoflurane (Sev), a commonly used volatile anesthetic, has been reported to inhibit the process of colorectal cancer (CRC). Circular RNAs (circRNAs) are revealed to participate in the pathogenesis of CRC. This study aims to reveal the mechanism of hsa_circ_0000231 in Sev-mediated CRC progression. Methods The expression of hsa_circ_0000231 and microRNA-622 (miR-622) was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Protein level was determined by western blot analysis. Cell proliferation was investigated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), cell colony formation and DNA content quantitation assays. Cell apoptosis was detected by Annexin V-fluorescein isothiocyanate and propidium iodide double staining and caspase 3 activity assays. Cell migration and invasion were investigated by wound-healing and transwell invasion assays, respectively. The putative relationship between hsa_circ_0000231 and miR-622 was predicted by circular RNA Interactome online database, and identified by dual-luciferase reporter and RNA immunoprecipitation assays. The impacts of hsa_circ_0000231 on Sev-mediated tumor formation in vivo were presented by in vivo assay. Results Hsa_circ_0000231 expression was upregulated, while miR-622 was downregulated in CRC tissues and cells compared with control groups. Sev treatment decreased hsa_circ_0000231 expression, but increased miR-622 expression in CRC cells. Sev treatment suppressed cell proliferation, migration and invasion, and induced cell apoptosis. Hsa_circ_0000231 overexpression restored Sev-mediated CRC progression in vitro. Additionally, hsa_circ_0000231 acted as a sponge of miR-622, and miR-622 inhibitors reversed the impacts of hsa_circ_0000231 silencing on CRC process. Furthermore, Sev treatment inhibited tumor growth by regulating hsa_circ_0000231 in vivo. Conclusion Hsa_circ_0000231 attenuated Sev-aroused repression impacts on CRC development by sponging miR-622. This findings may provide an appropriate anesthetic protocol for CRC sufferers undergoing surgery.