A natural gene drive system confers reproductive isolation in rice.

Hybrid sterility restricts the utilization of superior heterosis of indica-japonica inter-subspecific hybrids. In this study, we report the identification of RHS12, a major locus controlling male gamete sterility in indica-japonica hybrid rice. We show that RHS12 consists of two genes (iORF3/DUYAO and iORF4/JIEYAO) that confer preferential transmission of the RHS12-i type male gamete into the progeny, thereby forming a natural gene drive. DUYAO encodes a mitochondrion-targeted protein that interacts with OsCOX11 to trigger cytotoxicity and cell death, whereas JIEYAO encodes a protein that reroutes DUYAO to the autophagosome for degradation via direct physical interaction, thereby detoxifying DUYAO. Evolutionary trajectory analysis reveals that this system likely formed de novo in the AA genome Oryza clade and contributed to reproductive isolation (RI) between different lineages of rice. Our combined results provide mechanistic insights into the genetic basis of RI as well as insights for strategic designs of hybrid rice breeding.

Ultra-Tough, yet Rigid and Healable Supramolecular Polymers with Variable Stiffness for Multimodal Actuators.

Variable stiffness materials have shown considerable application in soft robotics. However, previously reported materials often struggle to reconcile high stiffness, stretchability, toughness, and self-healing ability, because of the inherently conflicting requisite of these properties in molecular design. Herein, we propose a novel strategy that involves incorporating acid-base ionic pairs capable of from strong crosslinking sites into a dense and robust hydrogen-bonding network to construct rigid self-healing polymers with tunable stiffness and excellent toughness. To demonstrate these distinct features, the polymer was employed to serve as the strain-regulation layers within a fiber-reinforced pneumatic actuator (FPA). The exceptional synergy between the configuration versatility of FPA and the dynamic molecular behavior of the supramolecular polymers equips the actuator with simultaneous improvement in motion dexterity, multimodality, loading capacity, robustness, and durability. Additionally, the concept of integrating high dexterity at both macro- and micro-scale is prospective to inspire the design of intelligent yet robust devices across various domains.

BCLAF1-induced HIF-1α accumulation under normoxia enhances PD-L1 treatment resistances via BCLAF1-CUL3 complex.

Bcl-2-associated transcription factor-1 (BCLAF1), an apoptosis-regulating protein of paramount significance, orchestrates the progression of various malignancies. This study reveals increased BCLAF1 expression in hepatocellular carcinoma (HCC) patients, in whom elevated BCLAF1 levels are linked to escalated tumor grades and diminished survival rates. Moreover, novel BCLAF1 expression is particularly increased in HCC patients who were not sensitive to the combined treatment of atezolizumab and bevacizumab, but not in patients who had tumors that responded to the combined regimen. Notably, overexpression of BCLAF1 increases HCC cell proliferation in vitro and in vivo, while the conditioned medium derived from cells overexpressing BCLAF1 strikingly enhances the tube-formation capacity of human umbilical vein endothelial cells. Furthermore, compelling evidence demonstrates that BCLAF1 attenuates the expression of prolyl hydroxylase domain protein 2 (PHD2) and governs the stability of hypoxia-inducible factor-1α (HIF-1α) under normoxic conditions without exerting any influence on transcription, as determined by Western blot and RT‒qPCR analyses. Subsequently, employing coimmunoprecipitation and immunofluorescence, we validated the reciprocal interaction between BCLAF1 and Cullin 3 (CUL3), through which BCLAF1 actively upregulates the ubiquitination and degradation of PHD2. The Western blot and RT‒qPCR results suggests that programmed death ligand-1 (PD-L1) is one of the downstream responders to HIF-1α in HCC. Thus, we reveal the pivotal role of BCLAF1 in promoting PD-L1 transcription and, through binding to CUL3, in promoting the accumulation of HIF-1α under normoxic conditions, thereby facilitating the ubiquitination and degradation of PHD2.

Superhydrophobic photothermal icephobic surfaces based on candle soot.

Ice accumulation causes various problems in our daily life for human society. The daunting challenges in ice prevention and removal call for novel efficient antiicing strategies. Recently, photothermal materials have gained attention for creating icephobic surfaces owing to their merits of energy conservation and environmental friendliness. However, it is always challenging to get an ideal photothermal material which is cheap, easily fabricating, and highly photothermally efficient. Here, we demonstrate a low-cost, high-efficiency superhydrophobic photothermal surface, uniquely based on inexpensive commonly seen candle soot. It consists of three components: candle soot, silica shell, and polydimethylsiloxane (PDMS) brushes. The candle soot provides hierarchical nano/microstructures and photothermal ability, the silica shell strengthens the hierarchical candle soot, and the grafted low-surface-energy PDMS brushes endow the surface with superhydrophobicity. Upon illumination under 1 sun, the surface temperature can increase by 53 °C, so that no ice can form at an environmental temperature as low as -50 °C and it can also rapidly melt the accumulated frost and ice in 300 s. The superhydrophobicity enables the melted water to slide away immediately, leaving a clean and dry surface. The surface can also self-clean, which further enhances its effectiveness by removing dust and other contaminants which absorb and scatter sunlight. In addition, after oxygen plasma treatment, the surface can restore superhydrophobicity with sunlight illumination. The presented icephobic surface shows great potential and broad impacts owing to its inexpensive component materials, simplicity, ecofriendliness, and high energy efficiency.

Depixelation and image restoration with meta-learning in fiber-bundle-based endomicroscopy.

In order to efficiently remove honeycomb artifacts and restore images in fiber-bundle-based endomicroscopy, we develop a meta-learning algorithm in this work. Two sub-networks are used to extract different levels of features. Meta-training is employed to train the network with small amount of simulated training data, enabling the optimal model to generalize to new tasks not seen in the training set. Numerical results on both USAF target and endomicroscopy images of living mice tissues demonstrate that the algorithm can restore high contrast image without pixilated noise using shorter time. Additionally, no prior information on the shape of the underlying tissues and the distribution of fiber bundles is required, making the method applicable to a variety of fiber-bundle-based endomicroscopy imaging conditions.

Hypoxia-induced miR-3677-3p promotes the proliferation, migration and invasion of hepatocellular carcinoma cells by suppressing SIRT5.

Hepatocellular carcinoma (HCC), with life-threatening malignant behaviours, often develops distant metastases and is the fourth most common primary cancer in the world, having taken millions of lives in Asian countries such as China. The novel miR-3677-3p is involved in a high-expression-related poor prognosis in HCC tissues and cell lines, indicating oncogenesis functions in vitro and in vivo. Initially, we confirmed the inhibition of proliferation, migration and invasion in miR-3677-3p knock-down MHCC-97H and SMMC-7721 cell lines, which are well known for their high degree of invasiveness. Then, we reversed the functional experiments in the low-miR-3677-3p-expression Hep3B cell line via overexpressing miR-3677-3p. In nude mice xenograft and lung metastasis assays, we found suppressor behaviours, smaller nodules and low density of organ spread, after injection of cells transfected with shRNA-miR-3677-3p. A combination of databases (Starbase, TargetScan and MiRgator) illustrated miR-3677-3p targets, and it was shown to suppress the expression of SIRT5 in a dual-luciferase reporter system. To clarify the conclusions of previous ambiguous research, we up-regulated SIRT5 in Hep3B cells, and rescue tests were established for confirmation that miR-3677-3p suppresses SIRT5 to enhance the migration and invasion of HCC. Interestingly, we discovered hypoxia-induced miR-3677-3p up-regulation benefited HCC malignancy and invasiveness. In conclusion, the overexpression of miR-3677-3p mediated SIRT5 inhibition, which could increase proliferation, migration and invasion of HCC in hypoxic microenvironments.

Long noncoding RNA PICSAR/miR-588/EIF6 axis regulates tumorigenesis of hepatocellular carcinoma by activating PI3K/AKT/mTOR signaling pathway.

Accumulating evidence has identified long noncoding RNAs (lncRNAs) as regulators in tumor progression and development. Here, we elucidated the function and possible molecular mechanisms of the effect of lncRNA-PICSAR (p38 inhibited cutaneous squamous cell carcinoma associated lincRNA) on the biological behaviors of HCC. In the present study, we found that PICSAR was upregulated in HCC tissues and cells and correlated with progression and poor prognosis in HCC patients. Gain- and loss-of-function experiments indicated that PICSAR enhanced cell proliferation, colony formation, and cell cycle progression and inhibited apoptosis of HCC cells. PICSAR could function as a competing endogenous RNA by sponging microRNA (miR)-588 in HCC cells. Mechanically, miR-588 inhibited HCC progression and alternation of miR-588 reversed the promotive effects of PICSAR on HCC cells. In addition, we confirmed that eukaryotic initiation factor 6 (EIF6) was a direct target of miR-588 in HCC and mediated the biological effects of miR-588 and PICSAR in HCC, resulting in PI3K/AKT/mTOR pathway activation. Our data identified PICSAR as a novel oncogenic lncRNA associated with malignant clinical outcomes in HCC patients. PICSAR played an oncogenic role by targeting miR-588 and subsequently promoted EIF6 expression and PI3K/AKT/mTOR activation in HCC. Our results revealed that PICSAR could be a potential prognostic biomarker and therapeutic target for HCC.

Dual pH/ROS-Responsive Nanoplatform with Deep Tumor Penetration and Self-Amplified Drug Release for Enhancing Tumor Chemotherapeutic Efficacy.

Poor deep tumor penetration and incomplete intracellular drug release remain challenges for antitumor nanomedicine application in clinical settings. Herein, a nanomedicine (RLPA-NPs) is developed that can achieve prolonged blood circulation, deep tumor penetration, active-targeting of cancer cells, endosome/lysosome escape, and intracellular selectivity self-amplified drug release for effective drug delivery. The RLPA-NPs are constructed by encapsulation of a pH-sensitive polymer octadecylamine-poly(aspartate-1-(3-aminopropyl) imidazole) (OA-P(Asp-API)) and a ROS-generation agent, ß-Lapachone (Lap), in micelles assembled by the tumor-penetration peptide internalizing RGD (iRGD)-modified ROS-responsive paclitaxel (PTX)-prodrug. iRGD could promote RLPA-NPs penetration into deep tumor tissue, and specific targeting to cancer cells. After internalization by cancer cells through receptor-mediated endocytosis, OA-P(Asp-API) can rapidly protonate in the endosome's acidic environment, resulting in RLPA-NPs escape from the endosome through the "proton sponge effect". At the same time, the RLPA-NPs micelle disassembles, releasing Lap and PTX-prodrug. Subsequently, the released Lap could generate ROS, consequently amplifying and accelerating PTX release to kill tumor cells. The in vitro and in vivo studies demonstrated that RLPA-NPs can significantly improve the therapeutic effect compared to control groups. Therefore, RLPA-NPs are a promising nanoplatform for overcoming multiple physiological and pathological barriers to enhance drug delivery.

Image reconstruction with a deep convolutional neural network in high-density super-resolution microscopy.

An accurate and fast reconstruction algorithm is crucial for the improvement of temporal resolution in high-density super-resolution microscopy, particularly in view of the challenges associated with live-cell imaging. In this work, we design a deep network based on a convolutional neural network to take advantage of its enhanced ability in high-density molecule localization, and introduce a residual layer into the network to reduce noise. The proposed scheme also incorporates robustness against variations of both the full width at half maximum (FWHM) and the pixel size. We validate our algorithm on both simulated and experimental data by achieving performance improvement in terms of loss value and image quality, and demonstrate live-cell imaging with temporal resolution of 0.5 seconds by recovering mitochondria dynamics.

MicroRNA-627-5p inhibits the proliferation of hepatocellular carcinoma cells by targeting BCL3 transcription coactivator.

Hepatocellular carcinoma (HCC) is a common malignant tumour. An increasing number of studies indicate that microRNAs (miRNAs) are critical regulators in the carcinogenesis and progression of HCC. MiR-627-5p has been identified as a tumour suppressor in colorectal cancer and glioblastoma multiforme. However, the function of miR-627-5p in HCC progression remains unclear yet. In our present study, miR-627-5p was determined to be low-expressed in HCC tissues and cell lines. Furthermore, miR-627-5p was expressed at significantly lower levels in HCC tissues with tumour size >5 cm or advanced tumour stages (III+IV). Additionally, HCC patients with low miR-627-5p level had a significantly poorer overall survival. Functionally, ectopic expression of miR-627-5p obviously inhibited the proliferation, and induced G1 phase arrest and apoptosis of Hep3B and SMMC-7721 cells. Conversely, miR-627-5p silencing facilitated HCC cell proliferation, cell cycle progression and apoptosis resistance. In vivo experiments further confirmed that miR-627-5p overexpression repressed the growth of Hep3B cells in mice. Mechanistically, BCL3 transcription coactivator was predicted as a direct target of miR-627-5p. MiR-627-5p overexpression reduced, whereas miR-627-5p knockdown enhanced the expression of BCL3 protein in HCC cells. Luciferase reporter assay confirmed the direct binding between miR-627-5p and 3'UTR of BCL3. The expression of BCL3 protein was negatively correlated with miR-627-5p level in HCC tissues. More importantly, re-expression of BCL3 partially reversed miR-627-5p induced inhibitory effects on Hep3B cells. In conclusion, these results demonstrated that miR-627-5p functioned as a tumour suppressor in HCC possibly by attenuating BCL3. This finding might offer a new therapeutic target for HCC treatment.

microRNA-1914, which is regulated by lncRNA DUXAP10, inhibits cell proliferation by targeting the GPR39-mediated PI3K/AKT/mTOR pathway in HCC.

Increasing studies have confirmed that abnormally expressed microRNAs (miRNAs) take part in the carcinogenesis as well as the aggravation of hepatocellular carcinoma (HCC). However, little information is currently available about miR-1914 in HCC. Here, we first confirmed that miR-1914 inhibition in HCC cell lines and tumour specimens correlates with tumour size and histological grade. In a series of functional experiments, miR-1914 inhibited tumour proliferation and colony formation, resulting in cell cycle arrest and increased apoptosis. Moreover, miR-1914 mediated its functional effects by directly targeting GPR39 in HCC cells, leading to PI3K/AKT/mTOR repression. Restoring GPR39 expression incompletely counteracted the physiological roles of miR-1914 in HCC cells. In addition, down-regulation of AKT phosphorylation inhibited the effects of miR-1914 in HCC. Furthermore, the overexpression of lncRNA DUXAP10 negatively correlated with the expression of miR-1914 in HCC; thus, lncRNA DUXAP10 regulated miR-1914 expression and modulated the GPR39/PI3K/AKT-mediated cellular behaviours. In summary, the present study demonstrated for the first time that lncRNA DUXAP10-regulated miR-1914 plays a functional role in inhibiting HCC progression by targeting GPR39-mediated PI3K/AKT/mTOR pathway, and this miRNA represents a novel therapeutic target for patients with HCC.

MicroRNA-301b-3p contributes to tumour growth of human hepatocellular carcinoma by repressing vestigial like family member 4.

MicroRNAs (miRNAs) are key regulators in the tumour growth and metastasis of human hepatocellular carcinoma (HCC). Increasing evidence suggests that miR-301b-3p functions as a driver in various types of human cancer. However, the expression pattern of miR-301b-3p and its functional role as well as underlying molecular mechanism in HCC remain poorly known. Our study found that miR-301b-3p expression was significantly up-regulated in HCC tissues compared to adjacent non-tumour tissues. Clinical association analysis revealed that the high level of miR-301b-3p closely correlated with large tumour size and advanced tumour-node-metastasis stages. Importantly, the high miR-301b-3p level predicted a prominent poorer overall survival of HCC patients. Knockdown of miR-301b-3p suppressed cell proliferation, led to cell cycle arrest at G2/M phase and induced apoptosis of Huh7 and Hep3B cells. Furthermore, miR-301b-3p knockdown suppressed tumour growth of HCC in mice. Mechanistically, miR-301b-3p directly bond to 3'UTR of vestigial like family member 4 (VGLL4) and negatively regulated its expression. The expression of VGLL4 mRNA was down-regulated and inversely correlated with miR-301b-3p level in HCC tissues. Notably, VGLL4 knockdown markedly repressed cell proliferation, resulted in G2/M phase arrest and promoted apoptosis of HCC cells. Accordingly, VGLL4 silencing rescued miR-301b-3p knockdown attenuated HCC cell proliferation, cell cycle progression and apoptosis resistance. Collectively, our results suggest that miR-301b-3p is highly expressed in HCC. miR-301b-3p facilitates cell proliferation, promotes cell cycle progression and inhibits apoptosis of HCC cells by repressing VGLL4.

lncRNA A1BG-AS1 suppresses proliferation and invasion of hepatocellular carcinoma cells by targeting miR-216a-5p.

Extensive evidence indicate that long noncoding RNAs (lncRNAs) regulates the tumorigenesis and progression of hepatocellular carcinoma (HCC). However, the expression and biological function of lncRNA A1BG antisense RNA 1 (A1BG-AS1) were poorly known in HCC. Here, we found the underexpression of A1BG-AS1 in HCC via analysis of The Cancer Genome Atlas database. Further analyses confirmed that A1BG-AS1 expression in HCC was markedly lower than that in noncancerous tissues based on our HCC cohort. Clinical association analysis revealed that low A1BG-AS1 expression correlated with poor prognostic features, such as microvascular invasion, high tumor grade, and advanced tumor stage. Follow-up data indicated that low A1BG-AS1 level evidently correlated with poor clinical outcomes of HCC patients. Moreover, forced expression of A1BG-AS1 repressed proliferation, migration, and invasion of HCC cells in vitro. Conversely, A1BG-AS1 knockdown promoted these malignant behaviors in HepG2 cells. Mechanistically, A1BG-AS1 functioned as a competing endogenous RNA by directly sponging miR-216a-5p in HCC cells. Notably, miR-216a-5p restoration rescued A1BG-AS1 attenuated proliferation, migration and invasion of HCCLM3 cells. A1BG-AS1 positively regulated the levels of phosphatase and tensin homolog and SMAD family member 7, which were reduced by miR-216a-5p in HCC cells. Altogether, we conclude that A1BG-AS1 exerts a tumor suppressive role in HCC progression.

Hypoxia-induced lncRNA EIF3J-AS1 accelerates hepatocellular carcinoma progression via targeting miR-122-5p/CTNND2 axis.

Long noncoding RNAs (lncRNAs) exert crucial roles in hepatocellular carcinoma (HCC) progression. LncRNA EIF3J-AS1 is recently reported to be highly expressed in HCC and correlates with recurrence-free survival. However, the biological function of EIF3J-AS1 and its underlying molecular mechanism are unexplored yet. In the current study, we demonstrated that EIF3J-AS1 expression was obviously upregulated in HCC tissues compared to adjacent noncancerous tissues. Moreover, the elevated levels of EIF3J-AS1 was detected in four HCC cell lines (HepG2, SMMC-7721, MHCC97H, HCCLM3) compared with the normal hepatic cell line LO2. Notably, the expression of EIF3J-AS1 was correlated with prognostic features including tumor size, vascular invasion and tumor stage. TCGA-LIHC data indicated that the upregulated expression of EIF3J-AS1 predicted poor prognosis of HCC. EIF3J-AS1 knockdown remarkably suppressed the proliferation, migration and invasion of HCC cells. Mechanistically, EIF3J-AS1 inversely regulated miR-122-5p expression via acting as a competing endogenous RNA (ceRNA) in HCC cells. Furthermore, catenin delta 2 (CTNND2) was recognized as a novel target of miR-122-5p. CTNND2 restoration partially reversed EIF3J-AS1 knockdown-induced inhibitory effects on HCC cell proliferation, migration and invasion. Importantly, we found that hypoxia induced EIF3J-AS1 and CTNND2 expression, and led to miR-122-5p downregulation in HCC cells. EIF3J-AS1 knockdown partially abolished hypoxia-induced HCC cell proliferation and mobility. In conclusion, our results provide a new insight into the molecular pathogenesis of HCC, and EIF3J-AS1 may be a potential therapeutic target for HCC.

Negatively Charged Carbon Nanodots with Bacteria Resistance Ability for High-Performance Antibiofilm Formation and Anticorrosion Coating Design.

Multifunctional coatings, especially those with simultaneous antibiofilm formation and anticorrosion properties are of great significance for the marine industry. Inspired by the function of fish mucus of blackhead fish, a biological epidermal secretion with negative surface potential that protects blackhead fish from colonization of microorganisms, a concept is introduced to use negatively charged carbon nanodots (CDs) as a secure and economical dual-functional additive to prepare protective coatings. The prepared CDs with strong negative surface potential initiate robust antibiofilm formation (antiadhesion and antibacteria) and anticorrosion properties (about 60 days' durability in seawater) of polymeric coatings. The incorporated CDs with negative surface potential take effect in the following ways: 1) suppressing bacterial adhesion by virtue of strong electrostatic repulsion; 2) sterilizing anchored bacteria via destroying bacterial cell walls; 3) impeding electron ejection from the metallic surface; and 4) blocking aggressive species (H2 O and O2 ) by narrowing the microchannels. This work provides a new train of thought propelling the development of potential materials for industrial and engineering applications.

Maltase Decorated by Chiral Carbon Dots with Inhibited Enzyme Activity for Glucose Level Control.

Carbon dots (CDs) have attracted increasing attention in disease therapy owing to their low toxicity and good biocompatibility. Their therapeutic effect strongly depends on the CDs structure (e.g., size or functional groups). However, the impact of CDs chirality on maltase and blood glucose level has not yet been fully emphasized and studied. Moreover, in previous reports, chiral CDs with targeted optical activity have to be synthesized from precursors of corresponding optical rotation, severely limiting chiral CDs design. Here, chiral CDs with optical rotation opposite to that of the precursor are facilely prepared through electrochemical polymerization. Interestingly, their chirality can be regulated by simply adjusting reaction time. At last, the resultant (+)-DCDs (700 µg mL-1 ) are employed to modify maltase in an effort to regulate the hydrolytic rate of maltose, showing an excellent inhibition ratio to maltase of 54.7%, significantly higher than that of (-)-LCDs (15.5%) in the same reaction conditions. The superior performance may be attributed to the preferable combination of DCDs with maltase. This study provides an electrochemical method to facilely regulate CDs chirality, and explore new applications of chiral CDs as antihyperglycemic therapy for controlling blood glucose levels.

Size Fractionation of Graphene Oxide Nanosheets via Controlled Directional Freezing.

The properties and functions of graphene oxide (GO)-based materials strongly depend on the lateral size and size distribution of GO nanosheets; therefore, GO and its derivatives with narrow size distributions are highly desired. Here we report the size fractionation of GO nanosheets by controlled directional freezing of GO aqueous dispersions. GO nanosheets with a narrow size distribution can be obtained by controlling the growth rate of the freezing front. This interesting phenomenon can be explained by the adsorption of GO nanosheets on the ice crystal surface in combination with the stratification of GO nanosheets at the ice growth front. Such a convenient size fractionation approach will be essential for practical applications of chemically modified graphene, including GO, reduced GO, and their assemblies or composites.

Long non-coding RNA CASC2 suppresses epithelial-mesenchymal transition of hepatocellular carcinoma cells through CASC2/miR-367/FBXW7 axis.

BACKGROUND: Recently, it has been reported that long non-coding RNA (lncRNA) cancer susceptibility candidate 2 (CASC2), a novel tumor suppressor, participates in regulating the carcinogenesis and suppresses tumor progression by sponging microRNAs (miRNAs). However, the expression and function of CASC2 in hepatocellular carcinoma (HCC) remain unclear. METHODS: The expression of CASC2 and miR-367 in HCC specimens and cell lines were detected by real-time PCR. Western blotting and immunohistochemistry were carried out for detection of epithelial-to-mesenchymal transition (EMT) markers in HCC. Transwell assays were used to determine migration and invasion of HCC cells. A mouse model for lung metastasis was established to evaluated HCC metastasis in vivo. The correlation among CASC2, miR-367 and F-box and WD repeat domain containing 7 (FBXW7) were disclosed by a dual-luciferase reporter assay, RIP assay and biotin pull-down assay. RESULTS: Here, CASC2 expression was significantly downregulated in HCC tissues, especially in aggressive and recurrent cases. In accordance, CASC2 underexpression was observed in HCC cell lines compared to LO2. In vitro and in vivo experiments revealed that CASC2 inhibited migration and invasion of HCC cells. Additionally, CASC2 repressed EMT process of HCC cells. Further studies demonstrated that CASC2 could function as a competing endogenous RNA (ceRNA) by sponging miR-367 in HCC cells. Functionally, gain- and loss-of-function studies showed that miR-367 promoted migration, invasion and EMT progression of HCC cells. Moreover, further investigations disclosed that FBXW7 was a downstream target of miR-367 and CASC2 prohibited EMT progression and subsequently exerted its anti-metastatic effects via CASC2/miR-367/FBXW7 axis in HCC cells. Clinically, CASC2 underexpression and miR-367 overexpression were closely correlated with the metastasis-associated clinicopathologic features. Notably, CASC2 low-expressing and miR-367 high-expressing HCC patients showed the poorest clinical outcome. CONCLUSIONS: Overall, we conclude that the CASC2/miR-367/FBXW7 axis may be a ponderable and promising therapeutic target for HCC.

Hypoxia Accelerates Aggressiveness of Hepatocellular Carcinoma Cells Involving Oxidative Stress, Epithelial-Mesenchymal Transition and Non-Canonical Hedgehog Signaling.

BACKGROUND/AIMS: Hypoxic microenvironment, a common feature of hepatocellular carcinoma (HCC), can induce HIF-1α expression and promote the epithelial-mesenchymal transition (EMT) and invasion of cancer cells. However, the underlying molecular mechanisms have not fully elucidated. METHODS: HCC cells were cultured under controlled hypoxia conditions or normoxic conditions. Transwell assays were used to examine the migration and invasion capacity. HIF-1α siRNA, cyclopamine (a SMO antagonist) and GLI1 siRNA were used to inhibit HIF-1α transcription or Hh signaling activation. RESULTS: In present study, we first observed a strongly positive correlation between HIF-1α and GLI1 expression in HCC tissues. Then, we showed that hypoxia significantly promoted EMT process and invasion of HCC cells, associated with activating the non-canonical Hh pathway without affecting SHH and PTCH1 expression. HIF-1α knockdown mitigated hypoxia-induced SMO and GLI1 expression, EMT invasion of HCC cells. Moreover, the SMO inhibitor or GLI1 siRNA also reversed the hypoxia-driven EMT and invasion of HCC cells under hypoxia condition. Here, we show that non-canonical Hh signaling is required as an important role to switch on hypoxia-induced EMT and invasion in HCC cells. In addition, we found that hypoxia increased ROS production and that ROS inhibitors (NAC) blocked GLI1-dependent EMT process and invasion under hypoxic conditions. To determine a major route of ROS production, we tested whether nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 4 (NOX4) is involved in hypoxia-induced ROS production. NOX4 expression was found to be increased at both mRNA and protein levels in hypoxic HCC cells. Furthermore, siRNA-mediated knockdown of NOX4 expression abolished hypoxia induced ROS generation and GLI1-dependent activation and invasion of HCC cells. CONCLUSION: Our findings indicate that hypoxia triggers ROS-mediated GLI1-dependent EMT progress and invasion of HCC cells through induction of NOX4 expression. Thus, hypoxia-driven ROS mediated non-canonical Hh signaling may play an important role in the initiation of EMT and provides a potential marker for cancer prevention and treatment.