TMX2 potentiates cell viability of hepatocellular carcinoma by promoting autophagy and mitophagy.

The dysregulation of membrane protein expression has been implicated in tumorigenesis and progression, including hepatocellular carcinoma (HCC). In this study, we aimed to identify membrane proteins that modulate HCC viability. To achieve this, we performed a CRISPR activation screen targeting human genes encoding membrane-associated proteins, revealing TMX2 as a potential driver of HCC cell viability. Gain- and loss-of-function experiments demonstrated that TMX2 promoted growth and tumorigenesis of HCC. Clinically, TMX2 was an independent prognostic factor for HCC patients. It was significantly upregulated in HCC tissues and associated with poor prognosis of HCC patients. Mechanistically, TMX2 was demonstrated to promote macroautophagy/autophagy by facilitating KPNB1 nuclear export and TFEB nuclear import. In addition, TMX2 interacted with VDAC2 and VADC3, assisting in the recruitment of PRKN to defective mitochondria to promote cytoprotective mitophagy during oxidative stress. Most interestingly, HCC cells responded to oxidative stress by upregulating TMX2 expression and cell autophagy. Knockdown of TMX2 enhanced the anti-tumor effect of lenvatinib. In conclusion, our findings emphasize the pivotal role of TMX2 in driving the HCC cell viability by promoting both autophagy and mitophagy. These results suggest that TMX2 May serve as a prognostic marker and promising therapeutic target for HCC treatment.

Deciphering the dynamics and driving mechanisms of high-risk antibiotic resistome in size-fractionated bacterial community during drinking water chlorination via metagenomic analysis.

To reveal the impact of chlorination on the high-risk resistome in size-fractionated bacterial community, we employed metagenomic approaches to decipher dynamics of high-risk antibiotic resistance genes (ARGs) and driving mechanisms in the free-living and particle-associated fractions within a full-scale drinking water treatment system. Our results revealed that chlorination significantly increased the relative abundance of high-risk ARGs in the free-living fraction to 0.33 ± 0.005 copies/cell (cpc), bacitracin and chloramphenicol resistance types were major contributors. Furthermore, chlorination significantly increased the relative abundance of mobile genetic elements (MGEs) in the free-living fraction, while decreasing it in the particle-associated fraction. During chlorination, size-fractionated bacterial communities varied considerably. Multiple statistical analyses highlighted the pivotal role of the bacterial community in altering high-risk ARGs in both the free-living and particle-associated fractions, while MGEs had a more pronounced impact on high-risk ARGs in the free-living fraction. Specifically, the enrichment of pathogenic hosts, such as Comamonas and Pseudomonas, led to an increase in the abundance of high-risk ARGs. Concurrently, MGEs exhibited significant correlations with high-risk ARGs, indicating the potential of horizontal transfer of high-risk ARGs. These findings provide novel insights for mitigating antibiotic resistance risk by considering different bacterial fractions and respective risk ranks in drinking water.

B4GALNT1 promotes hepatocellular carcinoma stemness and progression via integrin α2ß1-mediated FAK and AKT activation.

Background & Aims: ß-1,4-N-Acetyl-galactosaminyltransferase 1 (B4GALNT1) has been reported to contribute to the development of human malignancies. However, its role in hepatocellular carcinoma (HCC) remains uncharacterised. In this study, we aimed to elucidate the role of B4GALNT1 in HCC stemness and progression. Methods: Immunohistochemical staining was used to evaluate B4GALNT1 expression in HCC tissues and adjacent normal liver tissues. Flow cytometry analysis and sphere formation analysis were performed to investigate the role of B4GALNT1 in HCC stemness. Colony formation, Incucyte, wound-healing, Transwell migration, and invasion assays, and an animal model were used to study the role of B4GALNT1 in HCC progression. RNA-sequencing and co-immunoprecipitation were used to investigate the downstream targets of B4GALNT1. Results: B4GALNT1 was upregulated in HCC and associated with poor clinical outcome of patients with the disease. Moreover, B4GALNT1 promoted HCC stemness, migration, invasion, and growth. Mechanistically, B4GALNT1 not only promoted the expression of the integrin α2ß1 ligand THBS4, but also directly interacted with the ß subunit of integrin α2ß1 ITGB1 to inhibit its ubiquitin-independent proteasomal degradation, resulting in activation of FAK and AKT. Ophiopogonin D inhibited HCC stemness and progression by reducing ITGB1 and THBS4 expression and inhibiting FAK and AKT activation. Conclusions: Our study suggests the B4GALNT1/integrin α2ß1/FAK/PI3K/AKT axis as a therapeutic target for the inhibition of HCC stemness and tumour progression. Impact and implications: The role and regulatory mechanism of B4GALNT1 in HCC have not been studied previously. Here, we reveal that B4GALNT1 has a crucial role in HCC stemness and progression by activating the integrin α2ß1/FAK/PI3K/AKT axis, providing a potential target for HCC therapy. In addition, we find Ophiopogonin D as a potential therapeutic drug for patients with HCC.

SETD1A drives stemness by reprogramming the epigenetic landscape in hepatocellular carcinoma stem cells.

Cancer stem cells (CSCs) are responsible for tumor progression and recurrence. However, the mechanisms regulating hepatocellular carcinoma (HCC) stemness remain unclear. Applying a genome-scale CRISPR knockout screen, we identified that the H3K4 methyltransferase SETD1A and other members of Trithorax group proteins drive cancer stemness in HCC. SET domain containing 1A (SETD1A) was positively correlated with poor clinical outcome in patients with HCC. Combination of SETD1A and serum alpha fetoprotein substantially improved the accuracy of predicting HCC relapse. Mechanistically, SETD1A mediates transcriptional activation of various histone-modifying enzymes, facilitates deposition of trimethylated H3K4 (H3K4me3) and H3K27me3, and activates oncogenic enhancers and super-enhancers, leading to activation of oncogenes and inactivation of tumor suppressor genes simultaneously in liver CSCs. In addition, SETD1A cooperates with polyadenylate-binding protein cytoplasmic 1 to regulate H3K4me3 modification on oncogenes. Our data pinpoint SETD1A as a key epigenetic regulator driving HCC stemness and progression, highlighting the potential of SETD1A as a candidate target for HCC intervention and therapy.

Robust Learning with Noisy Ship Trajectories by Adaptive Noise Rate Estimation.

Ship trajectory classification is of great significance for shipping analysis and marine security governance. However, in order to cover up their illegal fishing or espionage activities, some illicit ships will forge the ship type information in the Automatic Identification System (AIS), and this label noise will significantly impact the algorithm's classification accuracy. Sample selection is a common and effective approach in the field of learning from noisy labels. However, most of the existing methods based on sample selection need to determine the noise rate of the data through prior means. To address these issues, we propose a noise rate adaptive learning mechanism that operates without prior conditions. This mechanism is integrated with the robust training paradigm JoCoR (joint training with co-regularization), giving rise to a noise rate adaptive learning robust training paradigm called A-JoCoR. Experimental results on real-world trajectories provided by the Danish Maritime Authority verified the effectiveness of A-JoCoR. It not only realizes the adaptive learning of the data noise rate during the training process, but also significantly improves the classification performance compared with the original method.

A Positron Emission Tomography Tracer Targeting the S2 Subunit of SARS-CoV-2 in Extrapulmonary Infections.

Tracking the pathogen of coronavirus disease 2019 (COVID-19) in live subjects may help estimate the spatiotemporal distribution of SARS-CoV-2 infection in vivo. This study developed a positron emission tomography (PET) tracer of the S2 subunit of spike (S) protein for imaging SARS-CoV-2. A pan-coronavirus inhibitor, EK1 peptide, was synthesized and radiolabeled with copper-64 after being conjugated with 1,4,7-triazacyclononane-1,4,7-triyl-triacetic acid (NOTA). The in vitro stability tests indicated that [64Cu]Cu-NOTA-EK1 was stable up to 24 h both in saline and in human serum. The binding assay showed that [64Cu]Cu-NOTA-EK1 has a nanomolar affinity (Ki = 3.94 ± 0.51 nM) with the S-protein of SARS-CoV-2. The cell uptake evaluation used HEK293T/S+ and HEK293T/S- cell lines that showed that the tracer has a high affinity with the S-protein on the cellular level. For the in vivo study, we tested [64Cu]Cu-NOTA-EK1 in HEK293T/S+ cell xenograft-bearing mice (n = 3) and pseudovirus of SARS-CoV-2-infected HEK293T/ACE2 cell bearing mice (n = 3). The best radioactive xenograft-to-muscle ratio (X/Nxenograft 8.04 ± 0.99, X/Npseudovirus 6.47 ± 0.71) was most evident 4 h postinjection. Finally, PET imaging in the surrogate mouse model of beta-coronavirus, mouse hepatic virus-A59 infection in C57BL/6 J mice showed significantly enhanced accumulation in the liver than in the uninfected mice (1.626 ± 0.136 vs 0.871 ± 0.086 %ID/g, n = 3, P < 0.05) at 4 h postinjection. In conclusion, our experimental results demonstrate that [64Cu]Cu-NOTA-EK1 is a potential molecular imaging probe for tracking SARS-CoV-2 in extrapulmonary infections in living subjects.

Ghrelin and ghrelin receptor (GHSR) in Chinese alligator, alligator sinensis: Molecular characterization, tissue distribution and mRNA expression changes during the active and hibernating periods.

The Chinese alligator (Alligator sinensis) is a freshwater crocodilian endemic to China. So far, the endocrine regulation of feeding and growth in Chinese alligator is poorly understood. In this study, the molecular structure and tissue expression profiles of ghrelin and its receptor GHSR in the Chinese alligator were characterized for the first time. The full-length cDNA of ghrelin was 1770 bp, including a 37 bp 5 '-UTR (untranslated region), a 435 bp ORF (open reading frame) and a 1298 bp 3 '-UTR. The ORF encodes a ghrelin precursor, which consists of 145 amino acid residues, including a signal peptide with 52 amino acid residues at the N-terminus, a mature peptide with 28 amino acid residues, and a possibly obestain at the C-terminus. The full-length cDNA of GHSR was 3961 bp, including a 5'-UTR of 375-bp, an ORF of 1059-bp and a 3' -UTR of 2527-bp. The ORF encodes a protein of 352 amino acid residues containing seven transmembrane domains, with multiple N glycosylation modification sites and conserved cysteine residue sites. The active core "GSSF" of Chinese alligator ghrelin was identical to that of mammals and birds, and the ghrelin binding site of GHSR was similar to that of mammals. The amino acid sequences of both ghrelin and GHSR share high identity with American alligator (Alligator mississippiensis) and birds. Ghrelin was highly expressed in cerebrum, mesencephalon, hypothalamus and multiple peripheral tissues, including lung, stomach and intestine, suggesting that it could play functions in paracrine and/or autocrine manners in addition to endocrine manner. GHSR expression level was higher in hypothalamus, epencephalon and medulla oblongata, and moderate in multiple peripheral tissues including lung, kindey, stomach and oviduct, implicating that ghrelin/GHSR system may participate in the regulation of energy balance, food intake, water and mineral balance, gastrointestinal motility, gastric acid secretion and reproduction. During hibernation, the expression of ghrelin and GHSR in the brain was significantly increased, while ghrelin was significantly decreased in heart, liver, lung, stomach, pancreas and ovary, and GHSR was significantly decreased in heart, liver, spleen, lung, kindey, stomach, ovary and oviduct. These temporal changes in ghrelin and GHSR expression could facilitate the physiological adaption to the hibernation of Chinese alligator. Our study could provide basic data for further studies on the regulation of feeding, physiological metabolism and reproduction of Chinese alligator, which could also be useful for the improvement of artificial breeding of this endangered species.

N6-methyladenosine-mediated LDHA induction potentiates chemoresistance of colorectal cancer cells through metabolic reprogramming.

Background: Chemoresistance to 5-fluorouracil (5-FU) is a major barrier to influence the treatment efficiency of colorectal cancer (CRC) patients, while the precise molecular mechanisms underlying 5-FU resistance remain to be fully elucidated. Methods: The metabolic profiles including ATP generation, glucose consumption, lactate generation, and oxygen consumption rate (OCR) in 5-FU resistant CRC cells were compared with those in their parental cells. Subsequently, a series of in vitro and in vivo experiments were carried out to investigate the mechanisms responsible for metabolic reprogramming of 5-FU resistant CRC cells. Results: We found that 5-FU resistant CRC cells showed increased levels of ATP generation, glucose consumption, lactate generation, and OCR as compared with those in their parental cells. Further, increased levels of mRNA N6-methyladenosine (m6A) and methyltransferase-like 3 (METTL3) were observed in 5-FU resistant CRC cells. Inhibition or knockdown of METTL3 can suppress glycolysis and restore chemosensitivity of 5-FU resistant CRC cells. Mechanistically, METTL3 enhances the expression of LDHA, which catalyzes the conversion of pyruvate to lactate, to trigger glycolysis and 5-FU resistance. METTL3 can increase the transcription of LDHA via stabilizing mRNA of hypoxia-inducible factor (HIF-1α), further, METTL3 also triggers the translation of LDHA mRNA via methylation of its CDS region and recruitment of YTH domain-containing family protein 1 (YTHDF1). Targeted inhibition of METTL3/LDHA axis can significantly increase the in vitro and in vivo 5-FU sensitivity of CRC cells. Conclusion: Our study indicates that METTL3/LDHA axis-induced glucose metabolism is a potential therapy target to overcome 5-FU resistance in CRC cells.

Mechanical strain regulates osteoclastogenesis via modulating the PTEN/PI3K/Akt signal pathway through miR-21.

Mechanical strain regulated osteoclastic differentiation and angiogenesis are crucial for bone modeling and remodeling, and previous data indicate that high-magnitude strain within physiological load regulates osteoclastic differentiation. However, the underlying mechanisms are still not fully understood. In the present study, the RAW264.7 mouse monocyte/macrophage was used as an osteoclast precursor, and the bone marrow-derived macrophages (BMMs) were isolated and cultured in vitro. The above cells were subjected to macrophage colony stimulating factor (M-CSF) and receptor activator of nuclear factor-kB ligand (RANKL) for the induction of osteoclast differentiation. Subsequently, the above cells were stretched by differential strain magnitudes to simulate the mechanical stimuli in the physiological conditions, and we found that low-magnitude strain (100 µÎµ) increased the expression levels of Acp5, Clcn7, MMP9 and Ctsk to promote osteoclastogenesis, while high-magnitude strain (3000 µÎµ) had opposite effects. In addition, we noticed that high-magnitude strain upregulated PTEN to inactivate the PI3K/Akt signaling pathway, and silencing of PTEN abrogated the suppressing effects of high-magnitude strain on osteoclastic differentiation. Next, we screened out that high-magnitude strain downregulated miR-21 to promote PTEN expressions in a competing endogenous RNA (ceRNA)-dependent manner. Finally, upregulation of miR-21 recovered osteoclastic differentiation in RAW264.7 and BMMs cells stimulated with high-magnitude strain. Collectively, our findings suggested that high-magnitude mechanical strain affected osteoclastic differentiation through modulating the miR-21/PTEN/PI3K/Akt signaling cascade, which provided potential strategies for the treatment of bone-related diseases. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10616-021-00507-x.

Cooperation of ATF4 and CTCF promotes adipogenesis through transcriptional regulation.

Adipogenesis is a multi-step process orchestrated by activation of numerous TFs, whose cooperation and regulatory network remain elusive. Activating transcription factor 4 (ATF4) is critical for adipogenesis, yet its regulatory network is unclarified. Here, we mapped genome-wide ATF4 binding landscape and its regulatory network by Chip-seq and RNA-seq and found ATF4 directly modulated transcription of genes enriching in fat cell differentiation. Motifs of TFs especially CTCF were found from ATF4 binding sites, suggesting a direct role of ATF4 in regulating adipogenesis associated with CTCF and other TFs. Deletion of CTCF attenuated adipogenesis while overexpression enhanced adipocyte differentiation, indicating CTCF is indispensable for adipogenesis. Intriguingly, combined analysis of Chip-seq data of these two TFs showed that ATF4 co-localized with CTCF in the promoters of key adipogenic genes including Cebpd and PPARg and co-regulated their transactivation. Moreover, ATF4 directly regulated CTCF expression and interacted with CTCF in differentiated 3T3-L1 cells. In vivo, downregulation of ATF4 suppressed the expression of CTCF, Cebpd, and PPARg, leading to reduced adipose tissue expansion in refeeding mice. Consistently, mRNA expression of ATF4 and CTCF was positively correlated with each other in human subcutaneous adipose tissue and inversely associated with BMI, indicating a possible involvement of these two TFs in adipose development. Taken together, our data propose for the first time that ATF4 and CTCF work cooperatively to control adipogenesis and adipose development via orchestrating transcription of adipogenic genes. Our findings reveal novel therapeutic targets in obesity treatment.

AFAP1-AS1: a rising star among oncogenic long non-coding RNAs.

Long non-coding RNAs (lncRNAs) have become a hotspot in biomedical research. This interest reflects their extensive involvement in the regulation of the expression of other genes, and their influence on the occurrence and development of a variety of human diseases. Actin filament associated protein 1-Antisense RNA 1(AFAP1-AS1) is a recently discovered oncogenic lncRNA. It is highly expressed in a variety of solid tumors, and regulates the expression of downstream genes and signaling pathways through adsorption and competing microRNAs, or by the direct binding to other proteins. Ultimately, AFAP1-AS1 promotes proliferation, chemotherapy resistance, and resistance to apoptosis, maintains stemness, and enhances invasion and migration of tumor cells. This paper summarizes the research concerning AFAP1-AS1 in malignant tumors, including the clinical application prospects of AFAP1-AS1 as a potential molecular marker and therapeutic target of malignant tumors. We also discuss the limitations in the knowledge of AFAP1-AS1 and directions of further research. AFAP1-AS1 is expected to provide an example for studies of other lncRNA molecules.

Identification of a new TRAF6 inhibitor for the treatment of hepatocellular carcinoma.

Tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6) is an E3 ubiquitin ligase that plays a crucial role in signal transduction. Previous studies have demonstrated that TRAF6 is overexpressed in hepatocellular carcinoma (HCC) and that TRAF6 knockdown dramatically attenuates tumor cell growth. Thus, TRAF6 may represent a potential therapeutic target for the treatment of HCC. Herein, we identified bis (4-hydroxy-3,5-dimethylphenyl) sulfone (TMBPS) as a novel inhibitor that can directly bind to and downregulate the level of TRAF6. In vitro experimental results showed that TMBPS arrests the cell cycle in the G2/M phase by inactivating the protein kinase B (AKT) and extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathways and induces apoptosis by activating the p38/mitogen-activated protein kinase (MAPK) signaling pathway. In addition, TMBPS exhibited significant tumor growth inhibition in mouse xenograft models. In summary, our findings offer a proof-of-concept for the use of TMBPS as a novel chemotherapy drug for the prevention or treatment of HCC.

The phosphorylation of CD147 by Fyn plays a critical role for melanoma cells growth and metastasis.

CD147, also known as extracellular matrix metalloproteinase inducer (EMMPRIN), is a transmembrane glycoprotein that is highly expressed in tumor cells, particularly melanoma cells, and plays critical roles in tumor cell metastasis through the regulation of matrix metalloprotease (MMP) expression. In this study, we identified Fyn as a novel interacting protein of CD147. Fyn is a member of the Src family of nonreceptor tyrosine kinases that regulates diverse physiological processes, such as T lymphocyte differentiation, through the TCR signaling pathway. Our findings demonstrated that Fyn directly phosphorylates CD147 at Y140 and Y183. Two phosphospecific antibodies against Y140 and Y183 were developed to validate the phosphorylation of CD147 by Fyn. Moreover, the CD147-FF (Y140F/Y183F) mutation impaired the interaction between CD147 and GnT-V, leading to decreased CD147 glycosylation and membrane recruitment. In addition, CD147-FF significantly blocked MMP-9 expression as well as cell migration. Moreover, we found that Fyn is overexpressed in clinical melanoma tissues as well as in melanoma cell lines. Knockdown of Fyn expression markedly attenuated the malignant phenotype of melanoma cells in vitro and in vivo through downregulation of CD147 phosphorylation, indicating that Fyn/CD147 is a potential target molecule in melanoma treatment. Finally, through virtual screening, we identified amodiaquine as a potential inhibitor targeting the Fyn/CD147 axis. Amodiaquine treatment dramatically inhibited the phosphorylation of CD147 by Fyn, thus attenuating melanoma cell growth and invasion in vitro and in vivo, suggesting that amodiaquine is a promising inhibitor for melanoma treatment.

Facile Synthesis of Nickel Cobalt Layered Double Hydroxide Nanosheets Intercalated with Sulfate Anion for High-Performance Supercapacitor.

Nickel-cobalt layered double hydroxide nanosheets intercalated with sulfate anion were fabricated via a facile hydrothermal method and investigated as high-performance electrode materials for supercapacitors. The morphology and electrochemical properties of the obtained samples could be controlled by changing molar ratios of the Ni and Co precursors. NiCo-LDHs with Ni/Co molar ratio of 0.35:0.65 exhibited high specific capacitance of 1551.1 F/g at the current density of 1 A/g and good cycling stability of 84.0% retention after 1000 charge/discharge cycles. On this basic, aqueous asymmetric supercapacitor (AAS) was successfully constructed by using the Ni0.35Co0.65-LDHs as the positive electrode and the activated carbon as the negative electrode. The as-built AAS was able to work in a working voltage window of 0~1.4 V and exhibited outstanding electrochemical performance. The Ni0.35Co0.65-LDHs//KOH activated cotton-derived carbon (ACDC) AAS showed the highest specific capacitance of 157.5 F/g, the satisfactory capacitance retention of 78.62% after 5000 cycles, the maximum energy density of 42.88 Wh/kg, and preferable combination of energy density of 30.63 Wh/kg with power density of 4.9 kW/kg at a current density of 7 A/g.

Reverse Screening Methods to Search for the Protein Targets of Chemopreventive Compounds.

This article is a systematic review of reverse screening methods used to search for the protein targets of chemopreventive compounds or drugs. Typical chemopreventive compounds include components of traditional Chinese medicine, natural compounds and Food and Drug Administration (FDA)-approved drugs. Such compounds are somewhat selective but are predisposed to bind multiple protein targets distributed throughout diverse signaling pathways in human cells. In contrast to conventional virtual screening, which identifies the ligands of a targeted protein from a compound database, reverse screening is used to identify the potential targets or unintended targets of a given compound from a large number of receptors by examining their known ligands or crystal structures. This method, also known as in silico or computational target fishing, is highly valuable for discovering the target receptors of query molecules from terrestrial or marine natural products, exploring the molecular mechanisms of chemopreventive compounds, finding alternative indications of existing drugs by drug repositioning, and detecting adverse drug reactions and drug toxicity. Reverse screening can be divided into three major groups: shape screening, pharmacophore screening and reverse docking. Several large software packages, such as Schrödinger and Discovery Studio; typical software/network services such as ChemMapper, PharmMapper, idTarget, and INVDOCK; and practical databases of known target ligands and receptor crystal structures, such as ChEMBL, BindingDB, and the Protein Data Bank (PDB), are available for use in these computational methods. Different programs, online services and databases have different applications and constraints. Here, we conducted a systematic analysis and multilevel classification of the computational programs, online services and compound libraries available for shape screening, pharmacophore screening and reverse docking to enable non-specialist users to quickly learn and grasp the types of calculations used in protein target fishing. In addition, we review the main features of these methods, programs and databases and provide a variety of examples illustrating the application of one or a combination of reverse screening methods for accurate target prediction.

MicroRNA-330-3p Expression Indicates Good Prognosis and Suppresses Cell Proliferation by Targeting Bmi-1 in Osteosarcoma.

BACKGROUND/AIMS: Growing evidence has shown that miR-330-3p is closely related to the biological behavior of cancer, including proliferation, metastasis, and prognosis. However, there have been no reports on miR-330-3p expression and function in osteosarcoma. METHODS: Expression of miR-330-3p in osteosarcoma tissues and cell lines was examined by quantitative PCR. Effects of miR-330-3p on osteosarcoma cell proliferation were investigated in vitro with the Cell Counting Kit-8 colorimetric assay. Targets of miR-330-3p were identified by dual-luciferase reporter assay. RESULTS: The results showed that expression of miR-330 decreased in osteosarcoma tissues and cell lines. Prognosis of patients with high miR-330-3p expression was much better than that of those with low expression (P=0.001), and multivariate analysis suggested that miR-330-3p is an independent prognostic factor for osteosarcoma. In addition, miR-330-3p overexpression significantly inhibited the growth of MG-63 and U2OS osteosarcoma cells. Dual-luciferase reporter assay demonstrated that Bmi-1 was a direct target gene of miR-330-3p, and in a recovery experiment, miR-330-3p suppressed osteosarcoma cell proliferation by directly targeting Bmi-1. CONCLUSION: Our results suggest that miR-330-3p acts as a tumor suppressor by regulating Bmi-1 expression in osteosarcoma. Thus, miR-330-3p may represent a novel therapeutic target for the treatment of osteosarcoma.

Epigenetic down regulation of G protein-coupled estrogen receptor (GPER) functions as a tumor suppressor in colorectal cancer.

BACKGROUND: Estrogenic signals are suggested to have protection roles in the development of colorectal cancer (CRC). The G protein-coupled estrogen receptor (GPER) has been reported to mediate non-genomic effects of estrogen in hormone related cancers except CRC. Its expression and functions in CRC were investigated. METHODS: The expression of GPER and its associations with clinicopathological features were examined. The mechanisms were further investigated using cells, mouse xenograft models, and clinical human samples. RESULTS: GPER was significantly (p < 0.01) down regulated in CRC tissues compared with their matched adjacent normal tissues in our two cohorts and three independent investigations from Oncomine database. Patients whose tumors expressing less (n = 36) GPER showed significant (p < 0.01) poorer survival rate as compared with those with greater levels of GPER (n = 54). Promoter methylation and histone H3 deacetylation were involved in the down regulation of GPER in CRC cell lines and clinical tissues. Activation of GPER by its specific agonist G-1 inhibited proliferation, induced cell cycle arrest, mitochondrial-related apoptosis and endoplasmic reticulum (ER) stress of CRC cells. The upregulation of reactive oxygen species (ROS) induced sustained ERK1/2 activation participated in G-1 induced cell growth arrest. Further, G-1 can inhibit the phosphorylation, nuclear localization, and transcriptional activities of NF-κB via both canonical IKKα/ IκBα pathways and phosphorylation of GSK-3ß. Xenograft model based on HCT-116 cells confirmed that G-1 can suppress the in vivo progression of CRC. CONCLUSIONS: Epigenetic down regulation of GPER acts as a tumor suppressor in colorectal cancer and its specific activation might be a potential approach for CRC treatment.