NAP1L5 Promotes Nucleolar Hypertrophy and Is Required for Translation Activation During Cardiomyocyte Hypertrophy

Pathological growth of cardiomyocytes during hypertrophy is characterized by excess protein synthesis; however, the regulatory mechanism remains largely unknown. Using a neonatal rat ventricular myocytes (NRVMs) model, here we find that the expression of nucleosome assembly protein 1 like 5 (Nap1l5) is upregulated in phenylephrine (PE)-induced hypertrophy. Knockdown of Nap1l5 expression by siRNA significantly blocks cell size enlargement and pathological gene induction after PE treatment. In contrast, Adenovirus-mediated Nap1l5 overexpression significantly aggravates the pro-hypertrophic effects of PE on NRVMs. RNA-seq analysis reveals that Nap1l5 knockdown reverses the pro-hypertrophic transcriptome reprogramming after PE treatment. Whereas, immune response is dominantly enriched in the upregulated genes, oxidative phosphorylation, cardiac muscle contraction and ribosome-related pathways are remarkably enriched in the down-regulated genes. Although Nap1l5-mediated gene regulation is correlated with PRC2 and PRC1, Nap1l5 does not directly alter the levels of global histone methylations at K4, K9, K27 or K36. However, puromycin incorporation assay shows that Nap1l5 is both necessary and sufficient to promote protein synthesis in cardiomyocyte hypertrophy. This is attributable to a direct regulation of nucleolus hypertrophy and subsequent ribosome assembly. Our findings demonstrate a previously unrecognized role of Nap1l5 in translation control during cardiac hypertrophy.

Gloeothece sp.—Exploiting a New Source of Antioxidant, Anti-Inflammatory, and Antitumor Agents

Bioactive lipidic compounds of microalgae, such as polyunsaturated fatty acids (PUFA) and carotenoids, can avoid or treat oxidation-associated conditions and diseases like inflammation or cancer. This study aimed to assess the bioactive potential of lipidic extracts obtained from Gloeothece sp.–using Generally Recognized as Safe (GRAS) solvents like ethanol, acetone, hexane:isopropanol (3:2) (HI) and ethyl lactate. The bioactive potential of extracts was assessed in terms of antioxidant (ABTS•+, DPPH•, •NO and O2•assays), anti-inflammatory (HRBC membrane stabilization and Cox-2 screening assay), and antitumor capacity (death by TUNEL, and anti-proliferative by BrdU incorporation assay in AGS cancer cells); while its composition was characterized in terms of carotenoids and fatty acids, by HPLC-DAD and GC-FID methods, respectively. Results revealed a chemopreventive potential of the HI extract owing to its ability to: (I) scavenge -NO• radical (IC50, 1258 ± 0.353 µg·mL−1); (II) inhibit 50% of COX-2 expression at 130.2 ± 7.4 µg·mL−1; (III) protect 61.6 ± 9.2% of lysosomes from heat damage, and (IV) induce AGS cell death by 4.2-fold and avoid its proliferation up to 40% in a concentration of 23.2 ± 1.9 µg·mL−1. Hence, Gloeothece sp. extracts, namely HI, were revealed to have the potential to be used for nutraceutical purposes.

KIF3A Inhibits NPC Proliferation, Migration and Invasion By Interacting With β-Catenin To Suppress Its Nuclear Accumulation

Background Nasopharyngeal carcinoma (NPC) is a malignant epithelial tumour that is prevalent in Southern China and other Southeast Asian countries. In previous studies, Kinesin Family Member 3A (KIF3A) was shown to play a dual role in cancers. However, the biological role of KIF3A in NPC and the underlying mechanism have not been reported. Methods The KIF3A mRNA and protein expressions in NPC were analyzed by qRT-PCR (Quantitative real-time polymerase chain reaction), Western blotting and immunohistochemistry. CCK-8, EDU incorporation assay, Colony formation, cell cycle assay, Wound-Healing Assay, Transwell verified KIF3A regulates the proliferation, migration, invasion of NPC cells. The in vivo effect of KIF3A on proliferation was elucidated with a xenograft mouse model. COIP (Co-immunoprecipitation) assay showed KIF3A interacts with β-catenin. Confocal microscopy colocalization assay confirmed colocalization of KIF3A and β-catenin in NPC cells. Nuclear and cytoplasmic extraction assays were performed to analyze the distribution of β-catenin in the nuclei and cytoplasm. Results In this study, we found that KIF3A interacts with β-catenin, suppressing the intranuclear aggregation of β-catenin, then inactivating the Wnt/β-catenin signaling pathway as well as the downstream cell cycle factors and EMT signal to inhibit NPC proliferation, migration, and invasion. Conclusions These findings suggest that KIF3A interacts with β-catenin and attenuates the malignant progression of NPC by inhibiting β-catenin intranuclear aggregation. KIF3A may be a promising therapeutic target for NPC patients.

Mutant NPM1-regulated lncRNA HOTAIRM1 promotes leukemia cell autophagy and proliferation by targeting EGR1 and ULK3

Background Acute myeloid leukemia (AML) with mutated nucleophosmin (NPM1), which displays a distinct long noncoding RNA (lncRNA) expression profile, has been defined as a unique subgroup in the new classification of myeloid neoplasms. However, the biological roles of key lncRNAs in the development of NPM1-mutated AML are currently unclear. Here, we aimed to investigate the functional and mechanistic roles of the lncRNA HOTAIRM1 in NPM1-mutated AML. Methods The expression of HOTAIRM1 was analyzed with a public database and further determined by qRT-PCR in NPM1-mutated AML samples and cell lines. The cause of upregulated HOTAIRM1 expression was investigated by luciferase reporter, chromatin immunoprecipitation and ubiquitination assays. The functional role of HOTAIRM1 in autophagy and proliferation was evaluated using western blot analysis, immunofluorescence staining, a Cell Counting Kit-8 (CCK-8) assay, a 5-ethynyl-2′-deoxyuridine (EdU) incorporation assay, flow cytometric analyses and animal studies. The action mechanism of HOTAIRM1 was explored through RNA fluorescence in situ hybridization, RNA pulldown and RNA immunoprecipitation assays. Results HOTAIRM1 was highly expressed in NPM1-mutated AML. High HOTAIRM1 expression was induced in part by mutant NPM1 via KLF5-dependent transcriptional regulation. Importantly, HOTAIRM1 promoted autophagy and proliferation both in vitro and in vivo. Mechanistic investigations demonstrated that nuclear HOTAIRM1 promoted EGR1 degradation by serving as a scaffold to facilitate MDM2-EGR1 complex formation, while cytoplasmic HOTAIRM1 acted as a sponge for miR-152-3p to increase ULK3 expression. Conclusions Taken together, our findings identify two oncogenic regulatory axes in NPM1-mutated AML centered on HOTAIRM1: one involving EGR1 and MDM2 in the nucleus and the other involving the miR-152-3p/ULK3 axis in the cytoplasm. Our study indicates that HOTAIRM1 may be a promising therapeutic target for this distinct leukemia subtype.

circEVI5 acts as a miR-4793-3p sponge to suppress the proliferation of gastric cancer

Circular RNAs (circRNAs) are a novel class of endogenous noncoding RNAs (ncRNAs) with a covalently closed loop structure. Accumulating evidence shows that circRNAs play vital roles in the growth, metastasis, treatment and prognosis of various cancers. However, the detailed functions and underlying mechanisms of circEVI5 (hsa_circ_0013162) in gastric cancer (GC) remain undocumented. In this study, the expression levels and prognostic value of circEVI5 were validated in GC tissue samples by using qRT-PCR. circEVI5 was significantly downregulated in GC tissues and cells, and low circEVI5 expression was correlated with poor prognosis. Next, in vitro CCK-8 assay, EdU incorporation assay, PI staining cell cycle assay, and in vivo xenograft mouse models were conducted to assess the functions of circEVI5. Gain of function experiments indicated that circEVI5 could inhibit GC cell proliferation and retard the cell cycle. Moreover, bioinformatics prediction showed that circEVI5 binds to miR-4793-3p, while FOXO1 may be a target of miR-4793-3p. Pull-down assays, RNA immunoprecipitation (RIP) assays, luciferase assays, and western blot were used to confirm the interactions between circEVI5, miR-4793-3p, and FOXO1. Functional assays demonstrated that circEVI5 suppressed the proliferation of GC by sponging miR-4793-3p and increasing FOXO1 expression levels. In conclusion, our study demonstrated that circEVI5 can bind miR-4793-3p as a ceRNA to eliminate the negative regulation of FOXO1, therefore suppressing GC proliferation.

Micro-RNA-338-3p Promotes the Development of Atherosclerosis by Targeting Desmin and Promoting Proliferation

Atherosclerosis (AS) is a dynamic and multi-stage process that involves various cells types, such as vascular smooth muscle cells (VSMCs) and molecules such as microRNAs. In this study, we investigated how miR-338-3p works in the process of AS. To determine how miR-338-3p was expressed in AS, an AS rat model was established and primary rat VSMCs were cultured. Real-time polymerase chain reaction was performed to detect miR-338-3p expression. Markers of different VSMC phenotypes were tested by Western blot. Immunofluorescent staining was employed to observe the morphologic changes of VSMCs transfected with miR-338-3p mimics. A dual luciferase reporter assay system was used to verify that desmin was a target of miR-338-3p. To further identify the role of miR-338-3p in the development of AS, VSMC proliferation and migration were evaluated by EdU incorporation assay, MTT assay, and wound healing assay. miR-338-3p expression was upregulated in the aortic tissues of an AS rat model and in primary rat VSMCs from a later passage. The transfection of miR-338-3p mimics in VSMCs promoted the synthetic cell phenotype. Bioinformatics analysis proposed desmin as a candidate target for miR-338-3p and the dual luciferase reporter assay confirmed in vivo that desmin was a direct target of miR-338-3p. The MTT and EdU incorporation assay revealed increased cell viability when miR-338-3p mimics were transfected. The increased expression of PCNA was a consistent observation, although a positive result was not obtained with respect to VSMC mobility. In AS, miR-338-3p expression was elevated. Elevated miR-338-3p inhibited the expression of desmin, thus promoting the contractile-to-synthetic VSMC phenotypic transition. In addition to morphologic changes, miR-338-3p enhanced the proliferative but not mobile ability of VSMCs. In summary, miR-338-3p promotes the development of AS.

Mechanoresponsive Smad5 Enhances MiR-487a Processing to Promote Vascular Endothelial Proliferation in Response to Disturbed Flow

MicroRNAs (miRs) and bone morphogenetic protein receptor–specific Smads are mechano-responsive molecules that play vital roles in modulating endothelial cell (EC) functions in response to blood flow. However, the roles of interplay between these molecules in modulating EC functions under flows remain unclear. We elucidated the regulatory roles of the interplay between miR-487a and Smad5 in EC proliferation in response to different flow patterns. Microarray and quantitative RT-PCR showed that disturbed flow with low and oscillatory shear stress (OS, 0.5 ± 4 dynes/cm2) upregulates EC miR-487a in comparison to static controls and pulsatile shear stress (12 ± 4 dynes/cm2). MiR-487a expression was higher in ECs in the inner curvature (OS region) than the outer curvature of the rat aortic arch and thoracic aorta and also elevated in diseased human coronary arteries. MiR-487a expression was promoted by nuclear phospho-Smad5, which bound to primary-miR-487a to facilitate miR-487a processing. Algorithm prediction and luciferase reporter and argonaute 2-immunoprecipitation assays demonstrated that miR-487a binds to 3′UTR of CREB binding protein (CBP) and p53. Knockdown and overexpression of miR-487a decreased and increased, respectively, phospho-Rb and cyclin A expressions through CBP and p53. A BrdU incorporation assay showed that miR-487a enhanced EC proliferation under OS in vitro and in disturbed flow regions of experimentally stenosed rat abdominal aorta in vivo. These results demonstrate that disturbed flow with OS induces EC expression of miR-487a through its enhanced processing by activated-Smad5. MiR-487 inhibits its direct targets CBP and p53 to induce EC cycle progression and proliferation. Our findings suggest that EC miR-487 may serve as an important molecular target for intervention against disturbed flow–associated vascular disorders resulting from atherosclerosis.

HTR7 Promotes Laryngeal Cancer Growth Through Activating PI3K/AKT Pathway

Background: Laryngeal cancer is a common malignancy of the head and neck, G protein-coupled receptors (GPCRs) are easily druggable in diseases. The 5-hydroxytryptamine receptor 7 (HTR7) belongs to the GPCR family; however, its role in laryngeal cancer remains unknown.Methods: MTT, Colony formation assay, BrdU incorporation assay, soft agar growth assay and xenograft tumor in nude mice were used to analyze the effect of HTR7 expression level on laryngeal cancer proliferation and growth.Results: We found that HTR7 was significantly upregulated in laryngeal cancer tissues and cells, and patients with high HTR7 expression had shorter survival time than those with low HTR7 expression. Univariate and multivariate Cox regression models showed HTR7 was an independent predictive factor for the prognosis of patients with laryngeal cancer. Cell proliferation assays and an animal model showed that HTR7 overexpression promoted laryngeal cancer proliferation and growth, while HTR7 knockdown inhibited laryngeal cancer proliferation and growth. Further analysis showed HTR7 activated the PI3K/AKT pathway, characterized by increased phosphorylation of AKT, luciferase reporter activity of FOXO factors and target expression. Inhibition of the PI3K/AKT pathway in HTR7-overexpressing cells suppressed proliferation and growth, suggesting HTR7 promoted laryngeal cancer proliferation and growth by activating the PI3K/AKT pathway.Conclusions: In summary, HTR7 is not only a target for laryngeal cancer therapy, but also a prognostic factor for the prognosis of patients with laryngeal cancer.

Antiproliferative Effects of Pterodon pubescens Extract and Isolated Diterpenes in HaCaT Cells

Pterodon pubescens fruits are popularly used because of their analgesic and anti-inflammatory actions, which are attributed to the isolated compounds with a vouacapan skeleton. This work aimed to evaluate the antiproliferative and anti-inflammatory effects of a P. pubescens fruit dichloromethane extract and the vouacapan diterpene furan isomerʼs mixture (1 : 1) (6α-hydroxy-7β-acetoxy-vouacapan-17β-oate methyl ester and 6α-acetoxy-7β-hydroxy-vouacapan-17β-oate methyl ester isomers) in HaCaT cells using the cell migration and the BrDU incorporation assay. Levels of IL-8 were measured by ELISA after TNF-α stimulation. HPLC/DAD analysis of the extract revealed the expressive presence of vouacapan diterpene furan isomerʼs mixture. P. pubescens extract (1.5625 – 25 µg/mL) and vouacapan diterpene furan isomerʼs mixture (3.125 – 50 µM) inhibited cell proliferation as indicated by a decreased BrdU-incorporation. For the evaluation of cell migration, time-lapse microscopy was used. P. pubescens presented inhibition on cell migration at all concentrations tested (3.125 – 12.5 µg/mL), whereas for the VDFI mixture, the inhibition was only observed at the highest concentrations (12.5 and 25 µM) tested. Furthermore P. pubescens extract and vouacapan diterpene furan isomerʼs mixture significantly decreased IL-8 levels. Our results showed antiproliferative and anti-inflammatory effects on HaCaT cells treated with the extract and the vouacapan isomerʼs mixture, without affecting cell viability. These activities could be attributed to the voucapan molecular structures. In conclusion, topical products developed of P. pubescens extract or the voucapan isomerʼs mixture should be further studied as a potential product for local treatment against hyperproliferative lesions as in psoriasis vulgaris, representing an alternative treatment approach.

MiR-25 Protects Against Apoptosis of Nucleus Pulposus Cells by Targeting SUMO2 in Intervertebral Disc Degeneration

Background MiR-25 was reported to be down-regulated in patients with intervertebral disc degeneration (IDD). However, the potential role of miR-25 in IDD remained unclear. Therefore, the present study aimed to investigate the effects of miR-25 on human intervertebral disc nucleus pulposus cells (NPCs).Methods We evaluated the expression of miR-25 and small ubiquitin-related modifier 2 (SUMO2) in human nucleus pulposus (NP) tissues by real-time PCR and western blotting. Then, the target relationship between miR-25 and SUMO2 was validated by luciferase reporter assay and biotin-coupled miRNA pulldown assay. The potential roles of miR-25 in NPC proliferation and apoptosis were confirmed using CCK-8 assay, EdU incorporation assay, and flow cytometry.Results MiR-25 was lowly expressed in the patients with IDD. In addition, miR-25 facilitated the growth of NPCs by increasing cell proliferation and inhibiting apoptosis. Furthermore, we elucidated that SUMO2 was a target gene of miR-25, and was regulated by miR-25 through p53 signaling pathway. Restore of SUMO2 expression abrogated the effects of miR-25 on NPCs.Conclusion MiR-25 promoted the proliferation, inhibited the apoptosis of NPCs, and suppressed the development of IDD via SUMO2-mediated p53 signaling axis.