ARRDC3 regulates the targeted therapy sensitivity of clear cell renal cell carcinoma by promoting AXL degradation.

AXL plays crucial roles in the tumorigenesis, progression, and drug resistance of neoplasms; however, the mechanisms associated with AXL overexpression in tumors remain largely unknown. In this study, to investigate these molecular mechanisms, wildtype and mutant proteins of arrestin domain-containing protein 3 (ARRDC3) and AXL were expressed, and co-immunoprecipitation analyses were performed. ARRDC3-deficient cells generated using the CRISPR-Cas9 system were treated with different concentrations of the tyrosine kinase inhibitor sunitinib and subjected to cell biological, molecular, and pharmacological experiments. Furthermore, immunohistochemistry was used to analyze the correlation between ARRDC3 and AXL protein expressions in renal cancer tissue specimens. The experimental results demonstrated that ARRDC3 interacts with AXL to promote AXL ubiquitination and degradation, followed by the negative regulation of downstream signaling mechanisms, including the phosphorylation of protein kinase B and extracellular signal-regulated kinase. Notably, ARRDC3 deficiency decreased the sunitinib sensitivity of clear cell renal cell carcinoma (ccRCC) cells in a manner dependent on the regulation of AXL stability. Overall, our results suggest that ARRDC3 is a negative regulator of AXL and can serve as a novel predictor of sunitinib therapeutic response in patients with ccRCC.

Predicting late-onset preeclampsia by detecting ELABELA content using an immunochromatographic colloidal gold test strip: Blood ELABELA content predicts the risk of pre-eclampsia.

Preeclampsia is a pregnancy disorder that seriously affects the outcome of mothers and infants and lacks effective prediction and diagnosis methods. ELABELA is the second endogenous ligand of the apelin receptor (APJ) and is associated with the pathogenesis of preeclampsia. In a previous study, the authors found that the downregulation of ELABELA expression is closely related to late-onset preeclampsia, which may be a marker for the clinical diagnosis of late-onset preeclampsia. In this study, the authors again collected 120 maternal blood samples, including 60 pregnant women with a medical diagnosis of late-onset preeclampsia. ELISA results showed that the serum ELABELA concentration in late-onset preeclampsia pregnant women (12.57 ± 7.77 ng/mL) was significantly lower than that in normal pregnant women (36.99 ± 23.58 ng/mL), which was consistent with previously reported results. Therefore, the authors used an ELABELA monoclonal antibody to label four colloidal gold nanoparticles with different diameters (15, 30, 55, and 150 nm) and developed a transverse-flow immunochromatographic band for the rapid and accurate detection of serum ELABELA levels. The strip test shows that colloidal gold with a diameter of 30 nm can be used as a good ELABELA detection marker and had more than 90% positive detection effect. Therefore, the authors hope that the colloidal gold strip with ELABELA as the diagnostic index developed by us will be popularized and applied in clinical diagnosis.

A Dynamic Model of Internationalization and Innovation in Emerging Market Enterprises: Knowledge Exploration, Transformation, and Exploitation.

Drawing on organizational learning theory and taking an institutional perspective, this study investigates (1) the dynamic relationship between internationalization and innovation in emerging market enterprises (EMEs), and (2) how state ownership moderates the focal relationships. Using a panel dataset of listed Chinese firms from 2007 to 2018, we find that internationalization encourages innovation input in EMEs, which in turn transforms into more innovation output. Higher innovation output leads to further international commitment, creating a dynamic upward spiral of internationalization and innovation. Interestingly, state ownership positively moderates the innovation input-innovation output link but negatively moderates the relationship between innovation output and internationalization. Our paper enriches and refines our understanding of the dynamic relationship between internationalization and innovation in EMEs by integrating the knowledge exploration, transformation, and exploitation perspectives, with the institutional perspective of state ownership.

The evolution of research on depression during COVID-19: A visual analysis using Co-Occurrence and VOSviewer.

Background: The COVID-19 pandemic has led to public health problems, including depression. There has been a significant increase in research on depression during the COVID-19 pandemic. However, little attention has been paid to the overall trend in this field based on bibliometric analyses. Methods: Co-Occurrence (COOC) and VOSviewer bibliometric methods were utilized to analyze depression in COVID-19 literature in the core collection of the Web of Science (WOS). The overall characteristics of depression during COVID-19 were summarized by analyzing the number of published studies, keywords, institutions, and countries. Results: A total of 9,694 English original research articles and reviews on depression during COVID-19 were included in this study. The United States, China, and the United Kingdom were the countries with the largest number of publications and had close cooperation with each other. Research institutions in each country were dominated by universities, with the University of Toronto being the most productive institution in the world. The most frequently published author was Ligang Zhang. Visualization analysis showed that influencing factors, adverse effects, and coping strategies were hotspots for research. Conclusion: The results shed light on the burgeoning research on depression during COVID-19, particularly the relationship between depression and public health. In addition, future research on depression during COVID-19 should focus more on special groups and those at potential risk of depression in the general population, use more quantitative and qualitative studies combined with more attention to scale updates, and conduct longitudinal follow-ups of the outcomes of interventions. In conclusion, this study contributes to a more comprehensive view of the development of depression during COVID-19 and suggests a theoretical basis for future research on public health.

An enhancer variant at 16q22.1 predisposes to hepatocellular carcinoma via regulating PRMT7 expression.

Most cancer causal variants are found in gene regulatory elements, e.g., enhancers. However, enhancer variants predisposing to hepatocellular carcinoma (HCC) remain unreported. Here we conduct a genome-wide survey of HCC-susceptible enhancer variants through a three-stage association study in 11,958 individuals and identify rs73613962 (T > G) within the intronic region of PRMT7 at 16q22.1 as a susceptibility locus of HCC (OR = 1.41, P = 6.02 × 10-10). An enhancer dual-luciferase assay indicates that the rs73613962-harboring region has allele-specific enhancer activity. CRISPR-Cas9/dCas9 experiments further support the enhancer activity of this region to regulate PRMT7 expression. Mechanistically, transcription factor HNF4A binds to this enhancer region, with preference to the risk allele G, to promote PRMT7 expression. PRMT7 upregulation contributes to in vitro, in vivo, and clinical HCC-associated phenotypes, possibly by affecting the p53 signaling pathway. This concept of HCC pathogenesis may open a promising window for HCC prevention/treatment.

RNA-binding motif protein 43 (RBM43) suppresses hepatocellular carcinoma progression through modulation of cyclin B1 expression.

RNA-binding proteins play key roles in the posttranscriptional regulation of mRNA during cancer progression. Here, we show that RNA-binding motif protein 43 (RBM43) is significantly downregulated in human tumors, and its low expression is correlated with poor prognosis in patients with HCC. Overexpression of RBM43 suppressed cell proliferation in culture and resulted in the growth arrest of tumor xenografts, whereas downregulating RBM43 played an opposite role. We have also demonstrated that overexpression or knockdown of RBM43 affects the cell-cycle progression of liver cancer cells. Mechanistically, RBM43 directly associated with the 3'UTR of Cyclin B1 mRNA and regulated its expression. Moreover, loss of Rbm43 in mice promoted liver carcinogenesis and HCC development after diethylnitrosamine (DEN)-carbon tetrachloride (CCl4) treatment. Taken together, our data indicate that RBM43 is a tumor suppressor that controls the cell cycle through modulation of Cyclin B1 expression, providing evidence that RBM43 is particularly important in HCC.

TCP10L negatively regulates alpha-fetoprotein expression in hepatocellular carcinoma.

Alpha-fetoprotein (AFP) is one of the most commonly used and reliable biomarkers for Hepatocellular carcinoma (HCC). However, the underlying mechanism of AFP expression in HCC is poorly understood. In this study, we found that TCP10L, a gene specifically expressed in the liver, is down-regulated in HCC and that its expression inversely correlates with AFP expression. Moreover, overexpression of TCP10L suppresses AFP expression whereas knockdown of TCP10L increases AFP expression, suggesting that TCP10L might be a negative regulator of AFP. We found that TCP10L is associated with the AFP promoter and inhibits AFP promoter-driven transcriptional activity. Taken together, these results indicate that TCP10L negatively regulates AFP expression in HCC and that it could be a potential prognostic marker and therapeutic target for HCC. [BMB Reports 2020; 53(8): 431-436].

RACK1 affects the progress of G2/M by regulating Aurora-A.

Aurora-A is a serine/threonine kinase, which is overexpressed in multiple human cancers and plays a key role in tumorigenesis and tumor development. In this study, we found that the receptor of activated C-kinase1 (RACK1), an important regulator of biological functions, interacted with Aurora-A and co-localized with Aurora-A at centrosomes. Moreover, RACK1 induces the auto-phosphorylation of Aurora-A in vitro and in vivo. Depletion of RACK1 impaired the activation of Aurora-A in late G2 phase, then inhibited the mitotic entry and leaded to multi-polarity, severe chromosome alignment defects, or centrosome amplification. Taken together, these results suggest that RACK1 is a new partner of Aurora-A and play a critical role in the regulation of the Aurora-A activity during mitosis, which may provide a basis for future anticancer studies targeting Aurora-A.

PARP12 (ARTD12) suppresses hepatocellular carcinoma metastasis through interacting with FHL2 and regulating its stability.

PARP12 is a mono-ADP-ribosyltransferase, but its function remains largely unknown. Here, we identified four-and-a-half LIM-only protein 2 (FHL2) as a functional partner of PARP12 through protein affinity purification. Although PARP12 did not mono-ADP-ribosylate FHL2 in vitro and in vivo, PARP12 deficiency decreased the protein level of FHL2 by promoting its ubiquitination and increased the expression level of transforming growth factor beta1 (TGF-ß1), which is independent of PARP12 enzymatic activity. We also provided evidence that PARP12 deficiency increased the migration and invasion of hepatocellular carcinoma (HCC) cells and promoted HCC metastasis in vivo by regulating the epithelial-mesenchymal transition process. These results indicated that PARP12 is a tumor suppressor that plays an important role in HCC metastasis through the regulation of FHL2 stability and TGF-ß1 expression.

Scinderin is a novel transcriptional target of BRMS1 involved in regulation of hepatocellular carcinoma cell apoptosis.

Tumor metastasis suppressor factor BRMS1 can regulate the metastasis of breast cancer and other tumors. Here we report scinderin (SCIN) as a novel transcriptional target of BRMS1. SCIN protein belongs to the cytoskeletal gelsolin protein superfamily and its involvement in tumorigenesis remains largely illusive. An inverse correlation between the expression levels of BRMS1 and SCIN was observed in hepatocellular carcinoma (HCC) cells and tissues. On the molecular level, BRMS1 binds to SCIN promoter and exerts a suppressive role in regulating SCIN transcription. FACS analysis and caspase 9 immunoblot reveal that knockdown of SCIN expression can sensitize HCC cells to chemotherapeutic drugs, leading to suppression of tumor growth in vivo. Consistently, overexpression of SCIN protects cells from apoptotic death, contributing to increased xenografted HCC cell growth. In summary, our study reveals SCIN as a functional apoptosis regulator as well as a novel target of BRMS1 during HCC tumorigenesis. Inhibition of SCIN might bring a potential cancer therapy approach.

Nogo-B promotes tumor angiogenesis and provides a potential therapeutic target in hepatocellular carcinoma.

Tumor angiogenesis is one of the hallmarks of cancer as well as an attractive target for cancer therapy. Characterization of novel pathways that act in parallel with the VEGF/VEGFR axis to promote tumor angiogenesis may provide insights into novel anti-angiogenic therapeutic targets. We found that the expression level of Nogo-B is positively correlated with tumor vessel density in hepatocellular carcinoma (HCC). While Nogo-B depletion inhibited tumor angiogenesis, Nogo-B overexpression promoted tumor angiogenesis in a tumor xenograft subcutaneous model of the human HCC cell line. Mechanically, Nogo-B regulates tumor angiogenesis based on its association with integrin αv ß3 and activation of focal adhesion kinase. Moreover, Nogo-B antibody successfully abolished the function of Nogo-B in tumor angiogenesis in vitro and in vivo. Collectively, our results strongly suggest that Nogo-B is an important tumor angiogenic factor and blocking Nogo-B selectively inhibits tumor angiogenesis.

The Vitamin K Epoxide Reductase Vkorc1l1 Promotes Preadipocyte Differentiation in Mice.

OBJECTIVE: Identification of novel regulators involved in adipose development is important to understand the molecular mechanism underlying obesity and associated metabolic disorders. Through isolation and analysis of a vitamin K epoxide reductase Vkorc1l1 mutant, this study aimed to disclose its function and underlying mechanism in adipose development and to obtain valuable insights regarding the mechanism of obesity. METHODS: A Vkorc1l1 mutation recovered from a forward genetic screen for obesity-related loci in mice was characterized to explore its effects in gene expression, animal metabolism, and adipose development. Adipogenesis was evaluated in both Vkorc1l1 mutant stromal vascular fraction and Vkorc1l1 knockdown preadipocytes. Intracellular vitamin K2 level and the effect of vitamin K2 on adipogenesis were tested in primary preadipocytes. RESULTS: Vkorc1l1 mutants displayed a considerably lower fat to body weight ratio, substantially decreased plasma leptin, and significantly underdeveloped white adipose tissue. Adipogenic defects related with Vkorc1l1 deficiency were observed both in vivo and in vitro. Vitamin K2 could inhibit adipogenesis in stromal vascular fraction. Increased intracellular vitamin K2 level was detected in Vkorc1l1 mutant preadipocytes. CONCLUSIONS: Vkorc1l1 promotes adipogenesis and possibly obesity. Downregulation of Vkorc1l1 increases intracellular vitamin K2 level and impedes preadipocyte differentiation.

Prolyl 4-hydroxylase 2 promotes B-cell lymphoma progression via hydroxylation of Carabin.

B-cell lymphomas are heterogeneous blood disorders with limited therapeutic options, largely because of their propensity to relapse and become refractory to treatments. Carabin, a key suppressor of B-cell receptor signaling and proliferation, is inactivated in B-cell lymphoma by unknown mechanisms. Here, we identify prolyl 4-hydroxylase 2 (P4HA2) as a specific proline hydroxylase of Carabin. Carabin hydroxylation leads to its proteasomal degradation, thereby activating the Ras/extracellular signal-regulated kinase pathway and increasing B-cell lymphoma proliferation. P4HA2 is undetectable in normal B cells but upregulated in the diffuse large B-cell lymphoma (DLBCL), driving Carabin inactivation and lymphoma proliferation. Our results indicate that P4HA2 is a potential prognosis marker for DLBCL and a promising pharmacological target for developing treatment of molecularly stratified B-cell lymphomas.

Effects of pore size on in vitro and in vivo anticancer efficacies of mesoporous silica nanoparticles.

Mesoporous silica nanoparticles (MSN) have been widely applied for drug delivery systems. To investigate the effects of pore size on anticancer efficacies, MSN with different pore sizes but similar particle sizes and surface charges were synthesized via a microemulsion method. The pore structures of MSN were characterized by transmission electron microscopy (TEM), small-angle X-ray scattering (SAXS), and N2 adsorption-desorption isotherms. Doxorubicin loaded MSN (DOX/MSN) were prepared and the minimum drug loading capacity was detected in DOX/MSN with a pore size of 2.3 nm (DOX/MSN2). DOX/MSN with a pore size of 8.2 nm (DOX/MSN8) showed a comparable drug loading amount in comparison with ones with a pore size of 5.4 nm (DOX/MSN5). In vitro drug release profiles showed that DOX/MSN5 could release DOX quickly and completely. Compared with DOX/MSN2 and DOX/MSN8, DOX/MSN5 showed the higher cellular uptake and nucleic concentration of DOX in QGY-7703 cells, which led to efficient cell-apoptosis induction and anti-proliferation effect, and thus the optimal in vivo anticancer activities. Taken together, these results highlighted the importance of pore size in anticancer efficacies, which would serve as a guideline in the rational design of MSN for cancer therapy.

Caspase polymorphisms and prognosis of hepatocellular carcinoma.

The aim of our study was to determine the impact of genetic polymorphisms in the caspase (CASP) genes on prognosis of hepatocellular carcinoma (HCC). We genotyped 7 potentially functional polymorphisms in CASP3, CASP7, CASP8, CASP9, CASP10 genes in 362 HCC patients of receiving surgical resection of HCC tumor. The associations of genotype and haplotype with overall survival (OS) and disease free survival (DFS) were analyzed by using the Cox proportional hazards model. We found that the CASP9 rs4645981 C allele was significantly associated with positive effect on DFS (P = 0.011 and 0.016 for CT+CC vs. TT in univariate and multivariate analysis, respectively), CT genotype was associated with a better OS of HCC than the TT genotype both in univariate and multivariate analysis (P = 0.048 and 0.041, respectively). Moreover, the CASP3 rs2705897 GT genotype showed marginally significant association with decreased OS and DFS, compared with the GG genotype. One haplotype TT/TG in CASP3 (constructed by rs12108497 T>C and rs2705897 T>G) was significantly associated with decreased OS and DFS, compared to the common haplotype TT/TT both in univariate analysis (P = 0.021 and 0.026, respectively) and multivariate analysis (P = 0.025 and 0.030, respectively). The haplotype GT/GT in CASP9 (constructed by rs4645978 A>G and rs4645981 C>T) was significantly associated with decreased DFS both in univariate and multivariate analysis (P = 0.012 and 0.010, respectively). In conclusion, the CASP9 rs4645981 polymorphism, CASP3 and CASP9 haplotypes may be useful prognosis markers for HCC patients with surgical resection of tumor.

Molecular chaperone CCT3 supports proper mitotic progression and cell proliferation in hepatocellular carcinoma cells.

CCT3 was one of the subunits of molecular chaperone CCT/TRiC complex, which plays a central role in maintaining cellular proteostasis. We demonstrated that expressions of CCT3 mRNA and protein are highly up-regulated in hepatocellular carcinoma (HCC) tissues, and high level of CCT3 is correlated with poor survival in cancer patients. In HCC cell lines, CCT3 depletion suppresses cell proliferation by inducing mitotic arrest at prometaphase and apoptosis eventually. We also identified CCT3 as a novel regulator of spindle integrity and as a requirement for proper kinetochore-microtubule attachment during mitosis. Moreover, we found that CCT3 depletion sensitizes HCC cells to microtubule destabilizing drug Vincristine. Collectively, our study suggests that CCT3 is indispensible for HCC cell proliferation, and provides a potential drug target for treatment of HCC.

TCP10L synergizes with MAD1 in transcriptional suppression and cell cycle arrest through mutual interaction.

T-complex protein 10A homolog 2 (TCP10L) was previously demonstrated to be a potential tumor suppressor in human hepatocellular carcinoma (HCC). However, little is known about the molecular mechanism. MAX dimerization protein 1 (MAD1) is a key transcription suppressor that is involved in regulating cell cycle progression and Myc-mediated cell transformation. In this study, we identified MAD1 as a novel TCP10L-interacting protein. The interaction depends on the leucine zipper domain of both TCP10L and MAD1. TCP10L, but not the interaction-deficient TCP10L mutant, synergizes with MAD1 in transcriptional repression, cell cycle G1 arrest and cell growth suppression. Mechanistic exploration further revealed that TCP10L is able to stabilize intracellular MAD1 protein level. Consistently, the MAD1-interaction-deficient TCP10L mutant exerts no effect on stabilizing the MAD1 protein. Taken together, our results strongly indicate that TCP10L stabilizes MAD1 protein level through direct interaction, and they cooperatively regulate cell cycle progression. [BMB Reports 2016; 49(6): 325-330].

The tumor suppressor proteins ASPP1 and ASPP2 interact with C-Nap1 and regulate centrosome linker reassembly.

Centrosome linker tethers interphase centrosomes together allowing them to function as a single microtubule organization center. The centrosome linker is disrupted at the onset of mitosis to ensure timely centrosome disjunction and bipolar spindle formation and is reassembled at the end of mitosis. While the mechanism controlling centrosome linker disassembly at early mitosis has been well explored, little is known about how the linker is subsequently reassembled before mitotic exit. Here we report that ASPP1 and ASPP2, two members of the apoptosis stimulating proteins of p53 (ASPP) family, are involved in centrosome linker reassembly. We showed that ASPP1/2 interacted with centrosome linker protein C-Nap1. Co-depletion of ASPP1 and ASPP2 inhibited re-association of C-Nap1 with centrosome at the end of mitosis. Moreover, ASPP1/2 facilitated the interaction between C-Nap1 and PP1α, and this interaction was significantly reduced by co-depletion of ASPP1/2. ASPP1/2 antagonized the NEK2A-mediated C-Nap1 Ser2417/2421 phosphorylation in a PP1-dependent manner. Co-depletion of ASPP1 and ASPP2 inhibited dephosphorylation of C-Nap1 (Ser2417/2421) at the end of mitosis. Based on these findings, we propose that ASPP1/2 act as PP1-targeting subunits to facilitate C-Nap1 dephosphorylation and centrosome linker reassembly at the end of mitosis.

Green synthesis of silver nanoparticles in xylan solution via Tollens reaction and their detection for Hg(2+).

This work reported a facile and green method to prepare highly stable and uniformly distributed Ag nanoparticles (AgNPs), in which a biopolymer xylan was used as the stabilizing and reducing agent via the Tollens reaction under microwave irradiation. Different variables were evaluated to optimize the reaction conditions. Complete characterization was performed using UV-Vis, XRD, TEM, size distribution analysis and XPS. The results revealed that AgNPs were well dispersed with diameters of 20-35 nm due to the packing of xylan. The optimal conditions were as follows: microwave irradiation temperature was 60-70 °C, microwave power was 800 W, microwave time was 30 min, the ratio of xylan to AgNO3 was 50 mg: 0.13 mmol, and ammonia concentration was 2%. In addition, the AgNPs were collected via high-speed centrifugal separation, and the supernatant was tested by HPAEC, GPC, FT-IR, and NMR. By comparing the structure of xylan before and after the reaction, the reaction mechanism was discussed. It was noted that the xylan-AgNPs composites showed high selectivity and sensitivity for Hg(2+) detection. The other 15 metal ions used had no obvious effect on the detection of Hg(2+), and the limit of detection (LOD) was 4.6 nM, which is lower than the allowed maximum level of 30 nM for drinking water by WHO. In addition, the xylan-AgNPs composites can be applied for Hg(2+) detection in real water samples. This study provides a novel way for the high-value utilization of a rich biomass resource, and a green method for the synthesis of AgNPs for the selective and sensitive detection of harmful heavy metals.