[Retracted] MicroRNA­584 prohibits hepatocellular carcinoma cell proliferation and invasion by directly targeting BDNF.

Following the publication of this paper, it was drawn to the Editor's attention by a concerned reader that the Transwell invasion assay data shown in Fig. 2C and D on p. 1997 were strikingly similar to data appearing in different form in other articles written by different authors at different research institutes that had either already been published, or were submitted for publication at around the same time (and in some cases, have subsequently been retracted).  Owing to the fact that the contentious data in the above article had already been published prior to its submission to Molecular Medicine Reports, the Editor has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a  reply. The Editor apologizes to the readership for any inconvenience caused. [Molecular Medicine Reports  20: 1994-2001, 2019; DOI: 10.3892/mmr.2019.10424].

A flavonoid metabolon: cytochrome b5 enhances B-ring trihydroxylated flavan-3-ols synthesis in tea plants.

Flavan-3-ols are prominent phenolic compounds found abundantly in the young leaves of tea plants. The enzymes involved in flavan-3-ol biosynthesis in tea plants have been extensively investigated. However, the localization and associations of these numerous functional enzymes within cells have been largely neglected. In this study, we aimed to investigate the synthesis of flavan-3-ols in tea plants, particularly focusing on epigallocatechin gallate. Our analysis involving the DESI-MSI method to reveal a distinct distribution pattern of B-ring trihydroxylated flavonoids, primarily concentrated in the outer layer of buds. Subcellular localization showed that CsC4H, CsF3'H, and CsF3'5'H localizes endoplasmic reticulum. Protein-protein interaction studies demonstrated direct associations between CsC4H, CsF3'H, and cytoplasmic enzymes (CHS, CHI, F3H, DFR, FLS, and ANR), highlighting their interactions within the biosynthetic pathway. Notably, CsF3'5'H, the enzyme for B-ring trihydroxylation, did not directly interact with other enzymes. We identified cytochrome b5 isoform C serving as an essential redox partner, ensuring the proper functioning of CsF3'5'H. Our findings suggest the existence of distinct modules governing the synthesis of different B-ring hydroxylation compounds. This study provides valuable insights into the mechanisms underlying flavonoid diversity and efficient synthesis and enhances our understanding of the substantial accumulation of B-ring trihydroxylated flavan-3-ols in tea plants.

lncRNA miR4458HG modulates hepatocellular carcinoma progression by activating m6A-dependent glycolysis and promoting the polarization of tumor-associated macrophages.

Long non-coding RNAs (lncRNAs) play significant roles in different biological functions of cancers. However, their function in the metabolism of glucose in patients with human hepatocellular carcinoma (HCC) remains largely unknown. In this study, HCC and paired intact liver tissues were utilized to examine the miR4458HG expression using qRT-PCR and human HCC cell lines to examine cell proliferation, colony formation, and glycolysis after transfection of siRNAs targeting miR4458HG or miR4458HG vectors. The molecular mechanism of miR4458HG was clarified through in situ hybridization, Western blotting, qRT-PCR, RNA pull-down, and RNA immunoprecipitation analysis. The results showed that the miR4458HG affected HCC cell proliferation, activated the glycolysis pathway, and promoted the polarization of tumor-associated macrophage in vitro and in vivo models. Mechanistically, miR4458HG bound IGF2BP2 (a key RNA m6A reader) and facilitated IGF2BP2-mediated target mRNA stability, including HK2 and SLC2A1 (GLUT1), and consequently altered HCC glycolysis and tumor cell physiology. At the same time, HCC-derived miR4458HG could be wrapped in the exosomes and promoted the polarization of tumor-associated macrophage by increasing ARG1 expression. Hence, miR4458HG is oncogenic in nature among patients with HCC. To develop an effective treatment strategy of HCC patients presenting with high glucose metabolism, physicians should focus on miR4458HG and its pathway.

New insights into the function of plant tannase with promiscuous acyltransferase activity.

Plant tannases (TAs) or tannin acyl hydrolases, a class of recently reported carboxylesterases in tannin-rich plants, are involved in the degalloylation of two important groups of secondary metabolites: flavan-3-ol gallates and hydrolyzable tannins. In this paper, we have made new progress in studying the function of tea (Camellia sinensis) (Cs) TA-it is a hydrolase with promiscuous acyltransferase activity in vitro and in vivo and promotes the synthesis of simple galloyl glucoses and flavan-3-ol gallates in plants. We studied the functions of CsTA through enzyme analysis, protein mass spectrometry, and metabolic analysis of genetically modified plants. Firstly, CsTA was found to be not only a hydrolase but also an acyltransferase. In the two-step catalytic reaction where CsTA hydrolyzes the galloylated compounds epigallocatechin-3-gallate or 1,2,3,4,6-penta-O-galloyl-ß-d-glucose into their degalloylated forms, a long-lived covalently bound Ser159-linked galloyl-enzyme intermediate is also formed. Under nucleophilic attack, the galloyl group on the intermediate is transferred to the nucleophilic acyl acceptor (such as water, methanol, flavan-3-ols, and simple galloyl glucoses). Then, metabolic analysis suggested that transient overexpression of TAs in young strawberry (Fragaria × ananassa) fruits, young leaves of tea plants, and young leaves of Chinese bayberry (Myrica rubra) actually increased the total contents of simple galloyl glucoses and flavan-3-ol gallates. Overall, these findings provide new insights into the promiscuous acyltransferase activity of plant TA.

[Retracted] MicroRNA­601 serves as a potential tumor suppressor in hepatocellular carcinoma by directly targeting PIK3R3.

Following the publication of this paper, it was drawn to the Editors' attention by a concerned reader that one of the data panels shown for the cell invasion assays in Fig. 2D was strikingly similar to another data panel that had appeared in different form in another article by different authors. Owing to the fact that the contentious data in the above article had already been published elsewhere prior to its submission to Molecular Medicine Reports, the Editor has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a reply. The Editor apologizes to the readership for any inconvenience caused. [Molecular Medicine Reports 19: 2431­2439, 2019; DOI: 10.3892/mmr.2019.9857].

Flavonol-Aluminum Complex Formation: Enhancing Aluminum Accumulation in Tea Plants.

Polyphenol-rich tea plants are aluminum (Al) accumulators. Whether an association exists between polyphenols and Al accumulation in tea plants remains unclear. This study revealed that the accumulation of the total Al and bound Al contents were both higher in tea samples with high flavonol content than in low, and Al accumulation in tea plants was significantly and positively correlated with their flavonol content. Furthermore, the capability of flavonols combined with Al was higher than that of epigallocatechin gallate (EGCG) and root proanthocyanidins (PAs) under identical conditions. Flavonol-Al complexes signals (94 ppm) were detected in the tender roots and old leaves of tea plants through solid-state 27Al nuclear magnetic resonance (NMR) imaging, and the strength of the signals in the high flavonol content tea samples was considerably stronger than that in the low flavonol content tea samples. This study provides a new perspective for studying Al accumulation in different tea varieties.

[Retracted] MicroRNA­497 inhibits cellular proliferation, migration and invasion of papillary thyroid cancer by directly targeting AKT3.

Following the publication of this paper, it was drawn to the Editors' attention by a concerned reader that certain of the data shown for the cell migration and invasion assays in Figs. 2C and 5C were strikingly similar to data appearing in different form in other articles by different authors. Owing to the fact that the contentious data in the above article had already been published elsewhere, or were already under consideration for publication, prior to its submission to Molecular Medicine Reports, the Editor has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a satisfactory reply. The Editor apologizes to the readership for any inconvenience caused. [Molecular Medicine Reports 16: 5815­5822, 2017; DOI: 10.3892/mmr.2017.7345].

microRNA-605 promotes cell proliferation, migration and invasion in non-small cell lung cancer by directly targeting LATS2.

[This retracts the article DOI: 10.3892/etm.2017.4538.].

MicroRNA-495 suppresses cell proliferation and invasion of hepatocellular carcinoma by directly targeting insulin-like growth factor receptor-1.

[This retracts the article DOI: 10.3892/etm.2017.5467.].

MicroRNA-139 targets fibronectin 1 to inhibit papillary thyroid carcinoma progression.

[This retracts the article DOI: 10.3892/ol.2017.7201.].

Insights into acylation mechanisms: co-expression of serine carboxypeptidase-like acyltransferases and their non-catalytic companion paralogs.

Serine carboxypeptidase-like acyltransferases (SCPL-ATs) play a vital role in the diversification of plant metabolites. Galloylated flavan-3-ols highly accumulate in tea (Camellia sinensis), grape (Vitis vinifera), and persimmon (Diospyros kaki). To date, the biosynthetic mechanism of these compounds remains unknown. Herein, we report that two SCPL-AT paralogs are involved in galloylation of flavan-3-ols: CsSCPL4, which contains the conserved catalytic triad S-D-H, and CsSCPL5, which has the alternative triad T-D-Y. Integrated data from transgenic plants, recombinant enzymes, and gene mutations showed that CsSCPL4 is a catalytic acyltransferase, while CsSCPL5 is a non-catalytic companion paralog (NCCP). Co-expression of CsSCPL4 and CsSCPL5 is likely responsible for the galloylation. Furthermore, pull-down and co-immunoprecipitation assays showed that CsSCPL4 and CsSCPL5 interact, increasing protein stability and promoting post-translational processing. Moreover, phylogenetic analyses revealed that their homologs co-exist in galloylated flavan-3-ol- or hydrolyzable tannin-rich plant species. Enzymatic assays further revealed the necessity of co-expression of those homologs for acyltransferase activity. Evolution analysis revealed that the mutations of the CsSCPL5 catalytic residues may have taken place about 10 million years ago. These findings show that the co-expression of SCPL-ATs and their NCCPs contributes to the acylation of flavan-3-ols in the plant kingdom.

Two UDP-Glycosyltransferases Catalyze the Biosynthesis of Bitter Flavonoid 7-O-Neohesperidoside through Sequential Glycosylation in Tea Plants.

Flavonoid glycosides are typical bitter and astringent tasting compounds that contribute to the taste of tea beverages. However, the genes that contribute to the biosynthesis of bitter compounds (e.g., flavanone 7-O-neohesperidoside) in tea plants have yet to be identified. In this study, we identified 194 UDP-glycosyltransferases (UGTs) from the tea transcriptome database. Among them, two genes, CsUGT75L12 and CsUGT79B28, encoding flavonoid 7-O-glycosyltransferase and 7-O-glucoside(1→2)rhamnosyltransferase, respectively, were identified from Camellia sinensis. In vitro, the purified recombinant enzyme rCsUGT75L12 specifically transports the glucose unit from UDP-glucose to the 7-OH position of the flavonoid to produce the respective 7-O-glucoside. rCsUGT79B28 regiospecifically transfers a rhamnose unit from UDP-rhamnose to the 2″-OH position of flavonoid 7-O-glucosides to produce flavonoid 7-O-di-glycosides. Additionally, the expression profiles of the two CsUGTs were correlated with the accumulation patterns of 7-O-glucoside and 7-O-neohesperidoside, respectively, in tea plants. These results indicated that the two CsUGTs are involved in the biosynthesis of bitter flavonoid 7-O-neohesperidoside through the sequential glucosylation and rhamnosylation of flavonoids in C. sinensis. Taken together, our findings provided not only molecular insights into flavonoid di-glycoside metabolism in tea plants but also crucial molecular markers for controlling the bitterness and astringent taste of tea.

ChaC glutathione specific γ-glutamylcyclotransferase 1 inhibits cell viability and increases the sensitivity of prostate cancer cells to docetaxel by inducing endoplasmic reticulum stress and ferroptosis.

The present study aimed to determine the effects and mechanism of ChaC glutathione specific γ-glutamylcyclotransferase 1 (CHAC1) on cell viability and the sensitivity of prostate cancer cells to docetaxel. Compared with non-tumor human prostate epithelial RWPE-1 cells, the mRNA and protein levels of CHAC1 significantly decreased in two prostate cancer cell lines, DU145 and 22RV1, as measured by quantitative polymerase chain reaction and western blot analysis (P<0.05). The cell viability and glutathione (GSH) levels were significantly inhibited in prostate cancer cells following overexpression of CHAC1 (P<0.01), while they were significantly increased in DU145 cells transfected with CHAC1 siRNA (P<0.05), but not in 22RV1 cells (P>0.05). The expression levels of several endoplasmic reticulum (ER) stress-related factors were then measured by western blot analysis. Following transfection with plasmid overexpressing CHAC1, ER markers, BIP and CHOP levels, were significantly upregulated (P<0.01), while GSH co-treatment decreased this upregulation. In addition, CHAC1 protein levels were significantly upregulated in cells treated with a ferroptosis activator (P<0.05). A liperflo reagent was then used to determine intracellular lipid peroxide levels. The intracellular lipid peroxides levels were significantly increased following CHAC1-overexpression (P<0.05), while GPX4 protein levels were significantly decreased (P<0.01). The cell viability was significantly inhibited (P<0.001) even with 1 nM docetaxel (DTX) and a plasmid overexpressing CHAC1, while the effect of inhibition was not significant at 1 nM of DTX alone (P>0.05). This inhibition was also eliminated following the addition of a ferroptosis inhibitor. In summary, CHAC1 may inhibit cell viability and increase the sensitivity of prostate cancer cells to DTX. The cellular mechanism may involve the induction of ER stress and ferroptosis. The results of the present study identified a potentially novel therapeutic target for prostate cancer, which may be useful in patients with castration-resistant prostate cancer.

CsHCT-Mediated Lignin Synthesis Pathway Involved in the Response of Tea Plants to Biotic and Abiotic Stresses.

Many studies have shown that phenolic compounds such as lignin and flavonoids enhance plant resistance. Tea plants are rich in flavonoid compounds. Whether these compounds are related to tea plant resistance is unclear. In this study, an interesting conclusion was drawn on the basis of experimental results: in response to abiotic stress (except for sucrose treatment), gene expression was increased in the phenylpropanoid and lignin pathways and was reduced in the flavonoid pathway in tea plants. CsHCTs, the genes located at the branch point of the lignin and flavonoid pathways, are most suitable for regulating the ratio of carbon flow in the lignin pathway and flavonoid synthesis. Enzymatic and genetic modification experiments proved that CsHCTs encode hydroxycinnamoyl-coenzyme A:shikimate/quinate hydroxycinnamoyl transferase in vitro and in vivo. Furthermore, the genetic modification results showed that the contents of phenolic acids and lignin were increased in tobacco and Arabidopsis plants overexpressing CsHCTs, whereas the content of flavonol glycosides was decreased. Both types of transgenic plants showed resistance to many abiotic stresses and bacterial infections. We speculate that CsHCTs participate in regulation of the metabolic flow of carbon from the flavonoid pathway to the chlorogenic acid, caffeoylshikimic acid, and lignin pathways to increase resistance to biotic and abiotic stresses.

GINS2 affects cell proliferation, apoptosis, migration and invasion in thyroid cancer via regulating MAPK signaling pathway.

Globally, thyroid cancer (TC) is considered to be the commonest endocrine malignancy. GINS complex subunit 2 (GINS2) belongs to the GINS complex family and is associated with cellular migration, invasion and growth. The present study aimed to investigate the underlying mechanisms of GINS2 on cell viability, migration and invasion in TC cells. By using MTT, wound healing and Transwell assays, the cell viability, migration and invasion were determined. Apoptosis was examined by immunofluorescence. Western blotting was used to detect protein expression levels. In the present study, biological function analysis demonstrated that GINS2 interference attenuated cell viability, migration and invasion in TC cell lines (K1 and SW579). It was discovered that, compared with the control group, GINS2 silencing induced apoptosis in TC cells. Additionally, GINS2 interference inhibited key proteins in the MAPK signaling pathway, including JNK, ERK and p38. According to these comparative experiments, GINS2 was considered to act a pivotal part in cell viability, migration and invasion of TC by regulating the MAPK signaling pathway and might be a potential therapeutic target for treating TC.

RBMX contributes to hepatocellular carcinoma progression and sorafenib resistance by specifically binding and stabilizing BLACAT1.

Hepatocellular carcinoma (HCC) is one of the top five causes of cancer death. The interaction of RNA binding proteins and long no coding RNA play vital role in malignant tumor progression, and even contribute to chemoresistance. RNA binding protein X (RBMX) plays a vital role in binding and stabilizing many proteins. In this study, we have identified RBMX significantly contributes to the tumorigenesis and sorafenib resistance of hepatocellular carcinoma (HCC). We observed that RBMX was highly expressed in both the HCC patient tissues and HCC cell lines. The HCC cell's viability, proliferation, and sorafenib resistance ability were both increased when RBMX was overexpressed. Additional, RBMX also promotes HCC development and chemoresistance in vivo. Further, we found that the autophagy level was increased in HCC cells, which RBMX was up regulated, with sorafenib processing. Interestingly, our study found that long no coding RNA bladder cancer associated transcript 1 (LncBLACAT1) was also raised in HCC. Mechanically, RIP, RNA pull-down and RNA Stability assay proved that RBMX could specially binds BLACAT1's mRNA and matins its expression, which is high degree of consistency with catRAPI database prediction. This mechanism of action is beneficial for cancer cells proliferation, anti-apoptotic, and colony formation with sorafenib treatment. Further, the autophagy level and cancer cell stemness were also improved when RBMX/BLACAT1 upregulated. Our study indicated that hepatoma cells can improve their proliferation, colony ability and autophagy by RBMX stabilizing BLACAT1 expression then promote HCC development and drug resistance. Hence, RBMX could be considered as novel therapeutic target for HCC treatment strategies.

Airborne fungus-induced biosynthesis of anthocyanins in Arabidopsis thaliana via jasmonic acid and salicylic acid signaling.

Anthocyanins are plant-specific pigments, the biosynthesis of which is stimulated by pathogen infection in several plant species. A. thaliana seedlings injected with airborne fungi can accumulate a high content of anthocyanins. The mechanism involved in fungus-induced anthocyanin accumulation in plants has not been fully described. In this study, the fungus Penicillium corylophilum (P. corylophilum), isolated from an Arabidopsis culture chamber, triggered jasmonic acid (JA), salicylic acid (SA), and anthocyanin accumulation in A. thaliana. Inhibitors of JA and SA biosynthesis suppressed the anthocyanin accumulation induced by P. corylophilum. The anthocyanin content was minimal in both the null mutant of JA-receptor coi1 and the null mutant of SA-receptor npr1 under P. corylophilum stimulation. The results indicate that JA and SA signaling mediated fungus-induced anthocyanin biosynthesis in A. thaliana. P. corylophilum led to different levels of anthocyanin generation in null mutants for MYB75, bHLH, EGL3, and GL3 transcription factors and WD40 protein, demonstrating that multiple MYB-bHLH-WD40 transcription factor complexes participated in fungus-induced anthocyanin accumulation in A. thaliana. The present study will help further elucidate the mechanism of plant resistance to pathogen infection.

Proanthocyanidin-Aluminum Complexes Improve Aluminum Resistance and Detoxification of Camellia sinensis.

Aluminum (Al) influences crop yield in acidic soil. The tea plant (Camellia sinensis) has high Al tolerance with abundant monomeric catechins in its leaves, especially epigallocatechin gallate (EGCG), and polymeric proanthocyanidins in its roots (rPA). The role of these polyphenols in the Al resistance of tea plants is unclear. In this study, we observed that these polyphenols could form complexes with Al in vitro, and complexation capacity was positively influenced by high solution pH (pH 5.8), polyphenol type (rPA and EGCG), and high Al concentration. In the 27Al nuclear magnetic resonance (NMR) experiment, rPA-Al and EGCG-Al complex signals could be detected both in vitro and in vivo. The rPA-Al and EGCG-Al complexes were detected in roots and old leaves, respectively, of both greenhouse seedlings and tea garden plants. Furthermore, in seedlings, Al accumulated in roots and old leaves and mostly existed in the apoplast in binding form. These results indicate that the formation of complexes with tea polyphenols in vivo plays a vital role in Al resistance in the tea plant.

GINS2 affects cell viability, cell apoptosis, and cell cycle progression of pancreatic cancer cells via MAPK/ERK pathway.

Background and Objective: GINS complex subunit 2 (GINS2), a member of the GINS complex, is involved in DNA replication. GINS2 is upregulated in a variety of aggressive tumors, such as leukemia, breast cancer, and cervical cancer. However, the role of GINS2 in pancreatic cancer has still remained elusive. In this study, PANC-1 and BxPC-3 cell lines were chosen to perform experiments in vitro. Additionally, the effects of GINS2 interference on the cell viability, cell apoptosis, cell cycle, and tumor growth in nude mice were analyzed. Methods: We utilized pancreatic cancer cell lines that knocked down GINS2 expression using small interference RNA (siRNA) and evaluated GINS2 expression using Western blot analysis. To explore the function of GINS2 in pancreatic cancer cell lines in vitro, MTT assay and flow cytometry were used. Additionally, we investigated the potential mechanism of GINS2 interference by identifying the MAPK/ERK pathway using Western blotting. Finally, PANC-1 cells with GINS2 knockdown were subcutaneously injected into nude mice to evaluate the effects of GINS2 on tumor growth in vivo. Results: It was unveiled that GINS2 interference inhibited cell viability, induced cell cycle arrest at G1 phase, and enhanced apoptosis of pancreatic cancer cell lines. Western blot assay indicated that GINS2 interference increased the expression level of Bax, while the expression level of Bcl-2 was remarkably decreased. In addition, the expression levels of CDK4, CDK6, and Cyclin D1 were significantly reduced after treatment with GINS2 siRNA. Furthermore, GINS2 interference drastically attenuated the expression levels of MEK, p-MEK, ERK, and p-ERK, belonging to the MAPK/ERK pathway. The results of an established cancer xenograft model revealed that nude mice transplanted with cells expressing negative control (NC) exhibited larger and heavier tumors, while volume and weight of tumor were remarkably reduced in ones transplanted with cells expressing GINS2 siRNA. Conclusions: GINS2 interference inhibited cell viability, induced cell cycle arrest, and promoted cell apoptosis of pancreatic cancer cell lines via the MAPK/ERK pathway, and our findings may be valuable for treating pancreatic cancer.

P4HB modulates epithelial-mesenchymal transition and the ß-catenin/Snail pathway influencing chemoresistance in liver cancer cells.

The aim of the present study was to investigate the role of prolyl 4-hydroxylase beta polypeptide (P4HB) in the chemoresistance of liver cancer. Drug-resistant liver cancer cell lines, such as HepG2/adriamycin (ADR) cells, were treated and screened using adriamycin. Gene interference was used to silence the expression of P4HB in liver cancer cells. Cell viability, invasiveness and migration were assessed using CCK8, Transwell and wound healing assays, respectively. In addition, changes to key genes and proteins in the epithelial-mesenchymal transition (EMT) and ß-catenin/Snail pathway were analyzed using reverse transcription-quantitative PCR and western blotting. Drug-resistant HepG2/ADR cells were successfully cultivated; the IC50 to ADR for HepG2/ADR and HepG2 cell lines was 4.85 and 0.61 µM, respectively. HepG2/ADR cells exhibited higher invasion and migration abilities compared with HepG2 cells (P<0.05). E-cadherin mRNA and protein expression levels in HepG2/ADR cells were decreased significantly, whereas P4HB, N-cadherin and vimentin mRNA and protein levels were significantly increased compared with HepG2 cells (all P<0.05). Knockdown of P4HB significantly decreased cell viability and the invasion and migration ability of HepG2/ADR cells. In addition, P4HB knockdown enhanced E-cadherin mRNA and protein expression levels, whereas N-cadherin, vimentin, total ß-catenin, nuclear ß-catenin and Snail mRNA and protein levels were significantly decreased (all P<0.05). Overall, the present study demonstrated that EMT and ß-catenin/Snail pathway influence P4HB modulation in liver cancer chemoresistance.