Loss of G3BP1 suppresses proliferation, migration, and invasion of esophageal cancer cells via Wnt/β-catenin and PI3K/AKT signaling pathways

A novel and independent survival prognostic model for OSCC: the functions and prognostic values of RNA-binding proteins

BACKGROUND

Oral squamous cell carcinoma (OSCC), exhibiting high morbidity and malignancy, is the most common type of oral cancer. The abnormal expression of RNA-binding proteins (RBPs) plays important roles in the occurrence and progression of cancer. The objective of the present study was to establish a prognostic assessment model of RBPs and to evaluate the prognosis of OSCC patients.

METHODS

Gene expression data in The Cancer Genome Atlas (TCGA) were analyzed by univariate Cox regression analysis model that established a novel nine RBPs, which were used to build a prognostic risk model. A multivariate Cox proportional regression model and the survival analysis were used to evaluate the prognostic risk model. Moreover, the receive operator curve (ROC) analysis was tested further the efficiency of prognostic risk model based on data from TCGA database and Gene Expression Omnibus (GEO).

RESULTS

Nine RBPs' signatures (ACO1, G3BP1, NMD3, RNGTT, ZNF385A, SARS, CARS2, YARS and SMAD6) with prognostic value were identified in OSCC patients. Subsequently, the patients were further categorized into high-risk group and low-risk in the overall survival (OS) and disease-free survival (DFS), and external validation dataset. ROC analysis was significant for both the TCGA and GEO. Moreover, GSEA revealed that patients in the high-risk group significantly enriched in many critical pathways correlated with tumorigenesis than the low, including cell cycle, adheres junctions, oocyte meiosis, spliceosome, ERBB signaling pathway and ubiquitin-mediated proteolysis.

CONCLUSIONS

Collectively, we developed and validated a novel robust nine RBPs for OSCC prognosis prediction. The nine RBPs could serve as an independent and reliable prognostic biomarker and guiding clinical therapy for OSCC patients.

Role of stress granules in tumorigenesis and cancer therapy

Stress granules (SGs) are membrane-less organelles that cell forms via liquid-liquid phase separation (LLPS) under stress conditions such as oxidative stress, ER stress, heat shock and hypoxia. SG assembly is a stress-responsive mechanism by regulating gene expression and cellular signaling pathways. Cancer cells face various stress conditions in tumor microenvironment during tumorigenesis, while SGs contribute to hallmarks of cancer including proliferation, invasion, migration, avoiding apoptosis, metabolism reprogramming and immune evasion. Here, we review the connection between SGs and cancer development, the limitation of SGs on current cancer therapy and promising cancer therapeutic strategies targeting SGs in the future.

Hitting the mark: Localization of mRNA and biomolecular condensates in health and disease

Subcellular mRNA localization is critical to a multitude of biological processes such as development of cellular polarity, embryogenesis, tissue differentiation, protein complex formation, cell migration, and rapid responses to environmental stimuli and synaptic depolarization. Our understanding of the mechanisms of mRNA localization must now be revised to include formation and trafficking of biomolecular condensates, as several biomolecular condensates that transport and localize mRNA have recently been discovered. Disruptions in mRNA localization can have catastrophic effects on developmental processes and biomolecular condensate biology and have been shown to contribute to diverse diseases. A fundamental understanding of mRNA localization is essential to understanding how aberrations in this biology contribute the etiology of numerous cancers though support of cancer cell migration and biomolecular condensate dysregulation, as well as many neurodegenerative diseases, through misregulation of mRNA localization and biomolecular condensate biology. This article is categorized under: RNA Export and Localization > RNA Localization RNA in Disease and Development > RNA in Disease RNA in Disease and Development > RNA in Development.

Role(s) of G3BPs in Human Pathogenesis

Ras-GTPase-activating protein (SH3 domain)-binding proteins (G3BP) are RNA binding proteins that play a critical role in stress granule (SG) formation. SGs protect critical mRNAs from various environmental stress conditions by regulating mRNA stability and translation to maintain regulated gene expression. Recent evidence suggests that G3BPs can also regulate mRNA expression through interactions with RNA outside of SGs. G3BPs have been associated with a number of disease states, including cancer progression, invasion, metastasis, and viral infections, and may be useful as a cancer therapeutic target. This review summarizes the biology of G3BP including their structure, function, localization, role in cancer progression, virus replication, mRNA stability, and SG formation. We will also discuss the potential of G3BPs as a therapeutic target. SIGNIFICANCE STATEMENT: This review will discuss the molecular mechanism(s) and functional role(s) of Ras-GTPase-activating protein (SH3 domain)-binding proteins in the context of stress granule formation, interaction with viruses, stability of RNA, and tumorigenesis.

HKDC1 reprograms lipid metabolism to enhance gastric cancer metastasis and cisplatin resistance via forming a ribonucleoprotein complex

As essential modulators of transcription and translation, RNA-binding proteins (RBPs) are frequently dysregulated in cancer. Bioinformatics study reveals that the RNA-binding protein hexokinase domain component 1 (HKDC1) is overexpressed in gastric cancer (GC). As HKDC1 plays a role in lipid homeostasis in the liver and glucose metabolism in certain cancers, the exact mechanism of action of HKDC1 in GC remains largely unknown. Upregulation of HKDC1 correlates with chemoresistance and poor prognosis in GC patients. HKDC1 enhances invasion, migration and resistance to cisplatin (CDDP) in GC cells in vitro and in vivo. Comprehensive transcriptomic sequencing and metabolomic analysis reveal that HKDC1 mediates abnormal lipid metabolism in GC cells. Herein, we identify a number of HKDC1-binding endogenous RNAs in GC cells, including protein kinase, DNA-activated, catalytic subunit (PRKDC) mRNA. We further validate that PRKDC is a crucial downstream effector of HKDC1 induced-GC tumorigenesis depends on lipid metabolism. Interestingly, G3BP1, a well-known oncoprotein, can be bound by HKDC1. HKDC1 cooperates with G3BP1 to enhance the stability of PRKDC transcript. Our results reveal a novel HKDC1/G3BP1-PRKDC regulatory axis that induces GC metastasis and chemoresistance via reprogramming lipid metabolism, which may provide an effective therapeutic strategy for a subset of GC with HKDC1 overexpression.

Mechanisms of human umbilical cord mesenchymal stem cells-derived exosomal lncRNA GAS5 in alleviating EMT of HPMCs via Wnt/β-catenin signaling pathway

BACKGROUND

Prolonged peritoneal dialysis (PD) can result in epithelial-to-mesenchymal transition (EMT) and peritoneal fibrosis (PF), which can cause patients to discontinue PD. It is imperative to urgently investigate effective measures to mitigate PF. This study aims to reveal mechanisms of exosomal lncRNA GAS5 derived from human umbilical cord mesenchymal stem cells (hUC-MSCs) on EMT of human peritoneal mesothelial cells (HPMCs) under high glucose (HG) conditions.

METHODS

HPMCs were stimulated with 2.5% glucose. The effects on EMT of HPMCs were observed by using an hUC-MSC conditioned medium (hUC-MSC-CM) and extracted exosomes. After hUC-MSCs were transfected with GAS5 siRNA, exosomes were extracted to act on HPMCs for detecting EMT markers, PTEN, and Wnt/β-catenin pathway, lncRNA GAS5 and miR-21 expressions in HPMCs.

RESULTS

We found that HG could induce the EMT of HPMCs. Compared with the HG group, the hUC-MSC-CM could alleviate the EMT of HPMCs induced by HG through exosomes. Exosomes in the hUC-MSC-CM entered HPMCs, by transferring lncRNA GAS5 to HPMCs, which down-regulates miR-21 and up-regulates PTEN, thus finally alleviating EMT of HPMCs. The Wnt/β-catenin pathway plays an essential role in alleviating EMT of HPMCs by exosomes in the hUC-MSC-CM. By transferring lncRNA GAS5 to HPMCs, exosomes derived from hUC-MSCs may competitively bind to miR-21 to regulate suppression on target PTEN genes and alleviate EMT of HPMCs through the Wnt/β-catenin pathway.

CONCLUSIONS

Exosomes from the hUC-MSCs-CM could alleviate the EMT of HPMCs induced by HG via regulating lncRNA GAS5/miR-21/PTEN through the Wnt/β-catenin signaling pathway.

Stress granules: functions and mechanisms in cancer

Stress granules (SGs) are non-enveloped structures formed primarily via protein and RNA aggregation under various stress conditions, including hypoxia and viral infection, as well as oxidative, osmotic, and heat-shock stress. SGs assembly is a highly conserved cellular strategy to reduce stress-related damage and promote cell survival. At present, the composition and dynamics of SGs are well understood; however, data on the functions and related mechanisms of SGs are limited. In recent years, SGs have continued to attract attention as emerging players in cancer research. Intriguingly, SGs regulate the biological behavior of tumors by participating in various tumor-associated signaling pathways, including cell proliferation, apoptosis, invasion and metastasis, chemotherapy resistance, radiotherapy resistance, and immune escape. This review discusses the roles and mechanisms of SGs in tumors and suggests novel directions for cancer treatment.

Quercetin acts via the G3BP1/YWHAZ axis to inhibit glycolysis and proliferation in oral squamous cell carcinoma

There is increasing evidence that the GTPase-activating protein SH3 domain-binding protein 1 (G3BP1) plays important roles in the formation of various tumors. However, the biological functions and mechanism of G3BP1 in promoting the progression of oral squamous cell carcinoma remain largely unknown. The impacts of quercetin on glycolysis and proliferation of the CAL27 oral squamous cell carcinoma line were investigated, and the mediating role of the G3BP1/YWHAZ pathway was explored. CAL27 cells stably over- or underexpressing G3BP1 were treated with quercetin, and then cell proliferation was assayed together with the expression of proteins involved in glucose uptake, glycolysis, and lactate production, as well as the activity of hexokinase, pyruvate kinase, and lactate dehydrogenase. CAL27 cells expressed G3BP1 and YWHAZ at significantly higher levels than normal oral squamous cells. CAL27 cells showed the highest expression of both proteins among the three carcinoma lines (TSCCA, SCC15, 42 CAL27). Overexpressing G3BP1 in CAL27 cells markedly induced glucose uptake, glycolysis, cell proliferation, and YWHAZ expression. Knocking down G3BP1 or YWHAZ exerted the opposite effects, which were similar to the effects of inhibiting glycolysis. Quercetin repressed glucose uptake, glycolysis, cell proliferation, and G3BP1/YWHAZ signaling in a dose-dependent way, and these effects were antagonized by G3BP1 overexpression. Quercetin can inhibit glycolysis and cell proliferation of oral squamous cell carcinoma, apparently by inhibiting the G3BP1/YWHAZ axis.

Stress granules dynamics: benefits in cancer

Stress granules (SGs) are stress-induced subcellular compartments, which carry out a particular function to cope with stress. These granules protect cells from stress-related damage and cell death through dynamic sequestration of numerous ribonucleoproteins (RNPs) and signaling proteins, thereby promoting cell survival under both physiological and pathological condition. During tumorigenesis, cancer cells are repeatedly exposed to diverse stress stimuli from the tumor microenvironment, and the dynamics of SGs is often modulated due to the alteration of gene expression patterns in cancer cells, leading to tumor progression as well as resistance to anticancer treatment. In this mini review, we provide a brief discussion about our current understanding of the fundamental roles of SGs during physiological stress and the effect of dysregulated SGs on cancer cell fitness and cancer therapy. [BMB Reports 2022; 55(12): 577-586].

Stress granules dynamics: benefits in cancer

Stress granules (SGs) are stress-induced subcellular compartments, which carry out a particular function to cope with stress. These granules protect cells from stress-related damage and cell death through dynamic sequestration of numerous ribonucleoproteins (RNPs) and signaling proteins, thereby promoting cell survival under both physiological and pathological condition. During tumorigenesis, cancer cells are repeatedly exposed to diverse stress stimuli from the tumor microenvironment, and the dynamics of SGs is often modulated due to the alteration of gene expression patterns in cancer cells, leading to tumor progression as well as resistance to anticancer treatment. In this mini review, we provide a brief discussion about our current understanding of the fundamental roles of SGs during physiological stress and the effect of dysregulated SGs on cancer cell fitness and cancer therapy. [BMB Reports 2022; 55(12): 577-586].

SIX3 function in cancer: progression and comprehensive analysis

The homeobox gene family encodes transcription factors that are essential for cell growth, proliferation, and differentiation, and its dysfunction is linked to tumor initiation and progression. Sine oculis homeobox (SIX) belongs to the homeobox gene family, with SIX3 being a core member. Recent studies indicate that SXI3 functions as a cancer suppressor or promoter, which is mainly dependent on SIX3's influence on the signal pathways that promote or inhibit cancer in cells. The low expression of SIX3 in most malignant tumors was confirmed by detailed studies, which could promote the cell cycle, proliferation, migration, and angiogenesis. The recovery or upregulation of SIX3 expression to suppress cancer is closely related to the direct or indirect inhibition of the Wnt pathway. However, in some malignancies, such as esophageal cancer and gastric cancer, SIX3 is a tumor-promoting factor, and repressing SIX3 improves patients' prognosis. This review introduces the research progress of SIX3 in tumors and gives a comprehensive analysis, intending to explain why SIX3 plays different roles in different cancers and provide new cancer therapy strategies.

FAM96A and FAM96B function as new tumor suppressor genes in breast cancer through regulation of the Wnt/β-catenin signaling pathway

AIMS

Family with sequence similarity 96 member A and B (FAM96A and FAM96B) are two highly conserved homologous proteins belonging to MIP18 family. Some studies have shown that FAM96A and FAM96B are significantly down-regulated in human gastrointestinal stromal tumors, colon cancer, and liver cancer. However, the molecular mechanisms of FAM96A/B in breast cancer are unknown. This work aims to explore the roles of FAM96A/B in breast cancer progression.

MAIN METHODS

Specific siRNAs were used to down-regulate FAM96A/B expression, and recombinant plasmids were used to up-regulate FAM96A/B expression in breast cancer cells. Cell proliferation was measured using MTT and colony formation. Cell cycle and apoptosis were detected by flow cytometry. Cell migration and invasion were examined by wound healing and transwell assays. The relationships among FAM96A/B, EMT and Wnt/β-catenin pathway were determined by analyzing expression changes of classical markers.

KEY FINDINGS

We found that FAM96A/B expression was down-regulated in breast cancer. FAM96A/B overexpression suppressed breast cancer cell proliferation, invasion and migration, induced cell apoptosis and caused cell cycle arrest. Conversely, FAM96A/B knockdown exhibited the opposite effects. Moreover, our data demonstrated that FAM96A/B overexpression suppressed EMT and Wnt/β-catenin pathway, while FAM96A/B knockdown showed the promoting effects on EMT and Wnt/β-catenin pathway. Furthermore, a Wnt pathway inhibitor, XAV-939 reversed the promoting effects of FAM96A/B knockdown on breast cancer progression.

SIGNIFICANCE

Our findings suggest that FAM96A/B may function as new tumor suppressor genes and inhibit breast cancer progression via modulating Wnt/β-catenin pathway, which can provide the potential markers for breast cancer diagnosis and therapy.

STAT3-EMT axis in tumors: modulation of cancer metastasis, stemness and therapy response

Epithelial-to-mesenchymal transition (EMT) mechanism is responsible for metastasis of tumor cells and their spread to various organs and tissues of body, providing undesirable prognosis. In addition to migration, EMT increases stemness and mediates therapy resistance. Hence, pathways involved in EMT regulation should be highlighted. STAT3 is an oncogenic pathway that can elevate growth rate and migratory ability of cancer cells and induce drug resistance. The inhibition of STAT3 signaling impairs cancer progression and promotes chemotherapy-mediated cell death. Present review focuses on STAT3 and EMT interaction in modulating cancer migration. First of all, STAT3 is an upstream mediator of EMT and is able to induce EMT-mediated metastasis in brain tumors, thoracic cancers and gastrointestinal cancers. Therefore, STAT3 inhibition significantly suppresses cancer metastasis and improves prognosis of patients. EMT regulators such as ZEB1/2 proteins, TGF-β, Twist, Snail and Slug are affected by STAT3 signaling to stimulate cancer migration and invasion. Different molecular pathways such as miRNAs, lncRNAs and circRNAs modulate STAT3/EMT axis. Furthermore, we discuss how STAT3 and EMT interaction affects therapy response of cancer cells. Finally, we demonstrate targeting STAT3/EMT axis by anti-tumor agents and clinical application of this axis for improving patient prognosis.

LINC02154 promotes the proliferation and metastasis of hepatocellular carcinoma by enhancing SPC24 promoter activity and activating the PI3K-AKT signaling pathway

BACKGROUND

Abnormal expression of long non-coding RNAs (lncRNAs) has been associated with the initiation and progression of hepatocellular carcinoma but, as yet, the clinicopathologic significance and potential role of Linc02154 in HCC remains to be determined. Here, we aimed to investigate the potential role and mode of action of Linc02154 in HCC.

METHODS

The expression of Linc02154 in 20 pairs of HCC/normal tissues and 7 HCC cell lines was detected by qRT-PCR. The localization of Linc02154 in HCC cells was detected using fluorescence in situ hybridization and nuclear-plasma separation assays. MTS, EdU incorporation, colony formation, flow cytometry, scratch wound-healing and transwell assays were performed to assess the role of Linc02154 in HCC cell proliferation, migration and invasion in vitro, and BALB/c nude mice xenografts were used to evaluate its role in vivo. RNA sequencing and Western blotting were used to evaluate the regulatory effect of Linc02154 on SPC24 gene expression. A dual-luciferase reporter assay was used to assess a putative interaction of Linc02154 with the SPC24 promoter.

RESULTS

We identified a new lncRNA, Linc02154, that is highly expressed in HCC cells and tissues of patients with a poor overall survival. Functional experiments revealed that exogenous Linc02154 expression in MHCC-97H and SK-Hep1 cells promoted their proliferation, migration and invasion in vitro and their tumorigenesis in vivo. Using a dual luciferase reporter assay we found that Linc02154 can enhance SPC24 promoter (-500 bp ~ -1000 region) activity. Exogenous over-expression of Linc02154 led to up-regulation of SPC24 by activating PI3K/AKT and its downstream signals, including cell cycle progression and EMT-associated gene expression.

CONCLUSION

Our data suggest that Linc02154 may serve as a valuable biomarker of HCC and as a potential therapeutic target.

The roles of G3BP1 in human diseases (review)

Ras-GTPase-activating protein binding protein 1 (G3BP1) is a multifunctional binding protein involved in a variety of biological functions, including cell proliferation, metastasis, apoptosis, differentiation and RNA metabolism. It has been revealed that G3BP1, as an antiviral factor, can interact with viral proteins and regulate the assembly of stress granules (SGs), which can inhibit viral replication. Furthermore, several viruses have the ability to hijack G3BP1 as a cofactor, recruiting translation initiation factors to promote viral proliferation. However, many functions of G3BP1 are associated with other diseases. In various cancers, G3BP1 is a cancer-promoting factor, which can promote the proliferation, invasion and metastasis of cancer cells. Moreover, compared with normal tissues, G3BP1 expression is higher in tumor tissues, indicating that it can be used as an indicator for cancer diagnosis. In this review, the structure of G3BP1 and the regulation of G3BP1 in multiple dimensions are described. In addition, the effects and potential mechanisms of G3BP1 on various carcinomas, viral infections, nervous system diseases and cardiovascular diseases are elucidated, which may provide a direction for clinical applications of G3BP1 in the future.

Sufentanil inhibits the proliferation and epithelial mesenchymal transition of lung cancer cells through Wnt/beta-catenin signaling pathway

Lung cancer is the most common malignancy and leading cause of cancer-related death. Sufentanil is a commonly used opioid anesthetic in clinics. This study aimed to explore the effects of sufentanil on the malignant behavior of lung cancer cells. H460 and H1299 lung cancer cell lines were selected for in vitro experiments. The MTT assay was conducted to detect cell viability. Proliferation ability was determined by colony formation and EdU assays. Transwell assays were performed to measure migration and invasion abilities. Western blotting was used to detect the expression of related proteins. LiCl was used to activate the Wnt/β-catenin signaling pathway. Sufentanil decreased the proliferation, migration, and invasion of H460 and H1299 cells. The protein expression levels of vimentin, N-cadherin, β-catenin, c-Myc, and MMP2 were downregulated, while those of E-cadherin and ZO-1 were upregulated after sufentanil treatment. LiCl treatment reversed the effects of sufentanil on H460 and H1299 cells. Sufentanil inhibited the proliferation, migration, invasion, and epithelial-mesenchymal transition of lung cancer cells by regulating the Wnt/β-catenin signaling pathway.

Tumor-promoting properties of karyopherin β1 in melanoma by stabilizing Ras-GTPase-activating protein SH3 domain-binding protein 1

The nuclear import receptor karyopherin β1 (KPNB1), a member of the Karyopherin protein family, is reported to be overexpressed in various cancers and promote carcinogenesis. By analyzing the correlation between the expression of KPNB1 and the overall survival rate of melanoma patients, we found that melanoma patients with higher expression of KPNB1 had worse survival. Furthermore, the database analyzed that the KPNB1 mRNA level was higher in melanoma samples than that in skin nevus tissues. We thus proposed that KPNB1 played a role in promoting melanoma development, and conducted gain-of- and loss-of-function experiments to test our hypothesis. We found that KPNB1 knockdown significantly retarded the growth and metastasis of melanoma cells in vitro and in vivo, and increased their sensitivity towards the anti-tumor drug cisplatin. KPNB1 overexpression had opposite effects. Notably, in melanoma cells, KPNB1 overexpression significantly decreased Ras-GTPase-activating protein SH3 domain-binding protein 1 (G3BP1) protein level, which was also overexpressed in melanoma samples and enhanced malignant behaviors of melanoma cells. We further demonstrated that KPNB1 overexpression induced deubiquitination of G3BP1, and prevented its degradation. However, KPNB1 overexpression hardly affected the nuclear translocation of G3BP1. Additionally, alterations induced by KPNB1 overexpression were partly reversed by G3BP1 inhibition. Therefore, the results suggest that KPNB1 may promote melanoma progression by stabilizing the G3BP1 protein. KPNB1-G3BP1 axis represents a potential therapeutic targetable node for melanoma.

Role of Main RNA Methylation in Hepatocellular Carcinoma: N6-Methyladenosine, 5-Methylcytosine, and N1-Methyladenosine

RNA methylation is considered a significant epigenetic modification, a process that does not alter gene sequence but may play a necessary role in multiple biological processes, such as gene expression, genome editing, and cellular differentiation. With advances in RNA detection, various forms of RNA methylation can be found, including N6-methyladenosine (m6A), N1-methyladenosine (m1A), and 5-methylcytosine (m5C). Emerging reports confirm that dysregulation of RNA methylation gives rise to a variety of human diseases, particularly hepatocellular carcinoma. We will summarize essential regulators of RNA methylation and biological functions of these modifications in coding and noncoding RNAs. In conclusion, we highlight complex molecular mechanisms of m6A, m5C, and m1A associated with hepatocellular carcinoma and hope this review might provide therapeutic potent of RNA methylation to clinical research.

Roles of WNT6 in Sheep Endometrial Epithelial Cell Cycle Progression and Uterine Glands Organogenesis

The uterus, as part of the female reproductive tract, is essential for embryo survival and in the maintenance of multiple pregnancies in domestic animals. This study was conducted to investigate the effects of WNT6 on Hu sheep endometrial epithelial cells (EECs) and uterine glands (UGs) in Hu sheep, with high prolificacy rates. In the present study, Hu sheep with different fecundity, over three consecutive pregnancies, were divided into two groups: high prolificacy rate group (HP, litter size = 3) and low prolificacy rate group (LP, litter size = 1). A comparative analysis of the endometrial morphology was performed by immunofluorescence. RNA-seq was used to analyze the gene’s expression in endometrium of HP and LP Hu sheep, providing a candidate gene, which was investigated in EECs and organoid culture. Firstly, higher density of UGs was found in the HP Hu sheep groups (p < 0.05). The RNA-seq data revealed the importance of the WNT signaling pathway and WNT6 gene in Hu sheep endometrium. Functionally, WNT6 could promote the cell cycle progression of EECs via WNT/β-catenin signal and enhance UGs organogenesis. Taken together, WNT6 is a crucial regulator for sheep endometrial development; this finding may offer a new insight into understanding the regulatory mechanism of sheep prolificacy.

CtBP2 interacts with TGIF to promote the progression of esophageal squamous cell cancer through the Wnt/β‑catenin pathway

C-terminal-binding protein 2 (CtBP2), a transcriptional co-repressor, plays a main role in tumorigenesis and in the development of multiple tumors. Transforming growth interacting factor (TGIF) is involved in a number of cellular signal transduction pathways and is related to tumor occurrence and development. In the present study, the proteins interacting with CtBP2 were identified and the mechanisms underlying the biological activity of CtBP2 in esophageal squamous cell carcinoma (ESCC) were investigated. The Search Tool for the Retrieval of Interacting Genes (STRING) database was used to search for known proteins interacting with CtBP2, and co-immunoprecipitation (Co-IP) assay was performed to validate the interactions. Reverse transcription-quantitative PCR (RT-qPCR), immunohistochemistry (IHC) and western blot analysis were performed to examine the expression levels of CtBP2 and TGIF in ESCC. The correlation between CtBP2 and TGIF was analyzed using Gene Expression Profiling Interactive Analysis (GEPIA) by Pearson's correlation analysis, and the co-localization of CtBP2 with TGIF in the ECA109 cells was identified using immunofluorescence staining. XAV939 treatment, CCK-8, 5-ethynyl-2′-deoxyuridine (EdU) staining, wound healing and Transwell assays were performed to investigate the signaling pathways involved in the biological activity of CtBP2 in ECA109 cells. According to the results obtained from STRING and Co-IP analysis, an interaction between CtBP2 and TGIF was indicated, and these proteins were co-localized in the nucleus. CtBP2 and TGIF mRNA and protein expression levels were robustly and simultaneously increased in both ESCC tissues and cell lines. There was a direct correlation between CtBP2 and TGIF expression levels in ESCC tissues, and both were significantly associated with metastasis and survival. The TGIF and CtBP2 expression levels were significantly increased or decreased simultaneously, in ECA109 cells transfected with LV-CtBP2 or sh-CtBP2, and vice versa. According to the results of CCK-8 assay, EdU staining and Transwell assay, CtBP2 promoted the proliferation, migration and invasion of ECA109 cells through the Wnt/β-catenin pathway. On the whole, the present study demonstrates that CtBP2 interacts with TGIF and promotes the malignant progression of ESCC through the Wnt/β-catenin pathway.

Identification of an Immune-Related Biomarker Model Based on the CircRNA-Associated Regulatory Network for Esophageal Carcinoma

Esophageal carcinoma (ESCA) is one of the most frequent types of malignant tumor that has a dismal prognosis. This research applied datasets aimed from the GEO and TCGA to create a prognostic signature for forecasting the clinical outcome of ESCA patients on the basis of a circRNA-associated regulatory network. Methods. A regulatory network associated with ESCA was established based on transcriptome data of circRNAs, miRNAs, and mRNAs. Functional annotations were implemented to further explore the mechanism of ESCA. Cox relative regression method was applied to create a risk signature. Besides, the immune microenvironment of the signature was investigated by utilizing the CIBERSORT algorithm. Results. Based on 27 DEcircRNAs, 65 DEmiRNAs, and 780 DEmRNAs, the circRNA-miRNA-mRNA network was finally set up. Functional enrichment unearthed that the regulatory network might participate in phosphorylation negative regulation, MAPK pathway, and PI3K/AKT pathway. This study established a risk scoring signature based on the seven immune-related genes (IRGs) (MARP14, RASGR1, PTK2, HMGB1, DKK1, RARB, and IGF1R), which was validated for its reliability. A stable and accurate nomogram combining immune-related risk scores with clinical features was constructed. Furthermore, we observed that the risk model was also related to the immunocyte infiltration. Conclusion. Our study successfully created a circRNA-associated regulatory network and further developed an immune-related model to forecast the clinical outcome of ESCA patients as well as to assess their immune status.

G3BP1 promotes human breast cancer cell proliferation through coordinating with GSK-3β and stabilizing β-catenin

Ras-GTPase activating SH3 domain-binding protein 1 (G3BP1) is a multifunctional binding protein involved in the development of a variety of human cancers. However, the role of G3BP1 in breast cancer progression remains largely unknown. In this study, we report that G3BP1 is upregulated and correlated with poor prognosis in breast cancer. Overexpression of G3BP1 promotes breast cancer cell proliferation by stimulating β-catenin signaling, which upregulates a number of proliferation-related genes. We further show that G3BP1 improves the stability of β-catenin by inhibiting its ubiquitin-proteasome degradation rather than affecting the transcription of β-catenin. Mechanistically, elevated G3BP1 interacts with and inactivates GSK-3β to suppress β-catenin phosphorylation and degradation. Disturbing the G3BP1-GSK-3β interaction accelerates the degradation of β-catenin, impairing the proliferative capacity of breast cancer cells. Our study demonstrates that the regulatory mechanism of the G3BP1/GSK-3β/β-catenin axis may be a potential therapeutic target for breast cancer.

Research Progress on the Structure and Function of G3BP

Ras-GTPase-activating protein (SH3 domain)-binding protein (G3BP) is an RNA binding protein. G3BP is a key component of stress granules (SGs) and can interact with many host proteins to regulate the expression of SGs. As an antiviral factor, G3BP can interact with viral proteins to regulate the assembly of SGs and thus exert antiviral effects. However, many viruses can also use G3BP as a proximal factor and recruit translation initiation factors to promote viral proliferation. G3BP regulates mRNA translation and attenuation to regulate gene expression; therefore, it is closely related to diseases, such as cancer, embryonic death, arteriosclerosis, and neurodevelopmental disorders. This review discusses the important discoveries and developments related G3BP in the biological field over the past 20 years, which includes the formation of SGs, interaction with viruses, stability of RNA, and disease progression.

The Wnt signaling pathway in tumorigenesis, pharmacological targets, and drug development for cancer therapy

Wnt signaling was initially recognized to be vital for tissue development and homeostasis maintenance. Further studies revealed that this pathway is also important for tumorigenesis and progression. Abnormal expression of signaling components through gene mutation or epigenetic regulation is closely associated with tumor progression and poor prognosis in several tissues. Additionally, Wnt signaling also influences the tumor microenvironment and immune response. Some strategies and drugs have been proposed to target this pathway, such as blocking receptors/ligands, targeting intracellular molecules, beta-catenin/TCF4 complex and its downstream target genes, or tumor microenvironment and immune response. Here we discuss the roles of these components in Wnt signaling pathway in tumorigenesis and cancer progression, the underlying mechanisms that is responsible for the activation of Wnt signaling, and a series of drugs targeting the Wnt pathway provide multiple therapeutic values. Although some of these drugs exhibit exciting anti-cancer effect, clinical trials and systematic evaluation should be strictly performed along with multiple-omics technology.

Elevated Serum SFRP5 Levels During Preeclampsia and Its Potential Association with Trophoblast Dysfunction via Wnt/β-Catenin Suppression

Preeclampsia (PE) is a life-threatening pregnancy complication associated with diminished trophoblast migration and invasion. Wnt signalling is one of the most important regulators of placentation. Secreted frizzled-related protein 5 (SFRP5) is an anti-inflammatory adipokine that may inhibit Wnt signalling. In this study, we aimed to investigate the relationship between SFRP5 and PE and its effect on trophoblast function, as well as the underlying signalling pathways. SFRP5 levels in the serum and placental tissues were detected using enzyme-linked immunosorbent assay and immunohistochemistry, respectively. To evaluate the effect of SFRP5 on Wnt signalling, the human trophoblast cell line HTR8/SVneo was treated with recombinant human SFRP5 and Dickkopf-related protein 1 (Dkk-1, canonical Wnt inhibitor) proteins and lithium chloride (LiCl, canonical Wnt agonist). The migration and invasion ability of HTR8/SVneo cells was evaluated using wound-healing and Matrigel Transwell assays. The activities of multiple matrix metalloproteinases (MMP)-2/9 were detected using gelatin zymography. Expression of glycogen synthase kinase-3 beta (GSK3β) and β-catenin proteins was investigated using western blotting. The serum SFRP5 levels were elevated in patients with PE, but SFRP5 expression was not detected in the placental tissues. Furthermore, SFRP5 inhibited the migration and invasion of HTR8/SVneo cells in vitro, increased GSK3β, and decreased β-catenin expression and MMP-2/9 activity in HTR8/SVneo cells. In conclusion, this study suggests that SFRP5 inhibits trophoblast migration and invasion potentially via the inhibition of Wnt/β-catenin signalling, which might be involved in the development of PE. However, the primary cause of the increased SFRP5 levels needs to be investigated.

The Importance of Being PI3K in the RAS Signaling Network

Ras proteins are essential mediators of a multitude of cellular processes, and its deregulation is frequently associated with cancer appearance, progression, and metastasis. Ras-driven cancers are usually aggressive and difficult to treat. Although the recent Food and Drug Administration (FDA) approval of the first Ras G12C inhibitor is an important milestone, only a small percentage of patients will benefit from it. A better understanding of the context in which Ras operates in different tumor types and the outcomes mediated by each effector pathway may help to identify additional strategies and targets to treat Ras-driven tumors. Evidence emerging in recent years suggests that both oncogenic Ras signaling in tumor cells and non-oncogenic Ras signaling in stromal cells play an essential role in cancer. PI3K is one of the main Ras effectors, regulating important cellular processes such as cell viability or resistance to therapy or angiogenesis upon oncogenic Ras activation. In this review, we will summarize recent advances in the understanding of Ras-dependent activation of PI3K both in physiological conditions and cancer, with a focus on how this signaling pathway contributes to the formation of a tumor stroma that promotes tumor cell proliferation, migration, and spread.

Cancer cell adaptability: turning ribonucleoprotein granules into targets

Stress granules (SGs) and processing bodies (P-bodies) are membraneless cytoplasmic condensates of ribonucleoproteins (RNPs). They both regulate RNA fate under physiological and pathological conditions, and are thereby involved in the regulation and maintenance of cellular integrity. During tumorigenesis, cancer cells use these granules to thrive, to adapt to the harsh conditions of the tumor microenvironment (TME), and to protect themselves from anticancer treatments. This ability to provide multiple outcomes not only makes RNP granules promising targets for cancer therapy but also emphasizes the need for more knowledge about the biology of these granules to achieve clinical use. In this review we focus on the role of RNP granules in cancer, and on how their composition and regulation might be used to elaborate therapeutic strategies.

G3BP1 may serve as a potential biomarker of proliferation, apoptosis, and prognosis in oral squamous cell carcinoma

BACKGROUND

G3BP1 is a prognostic biomarker for many types of cancers; however, its role in oral squamous cell carcinoma remains unclear. We investigated the role of G3BP1 as a potential biomarker for proliferation, apoptosis, and prognosis in oral squamous cell carcinoma.

METHODS

We obtained samples of normal oral mucosa (n = 17), oral squamous cell carcinoma tissues (n = 61), and paired adjacent tissues (n = 47) from Xiangya Hospital for immunohistochemical evaluation to measure the expression of G3BP1, E-cadherin, Ki67, and Cleaved-caspase3. Using data from The Cancer Genome Atlas, we performed bioinformatics analysis to investigate the prognosis, functions, signaling pathways, and immune infiltrate significance related to G3BP1 in oral squamous cell carcinoma.

RESULTS

The G3BP1 protein level was significantly upregulated in oral squamous cell carcinoma tissues and was also positively associated with Ki67 and negatively associated with Cleaved-caspase3. Based on information available in online database, the G3BP1 mRNA level was significantly higher in oral squamous cell carcinoma than in normal tissues. High G3BP1 mRNA levels were associated with poor overall survival rates in patients with oral squamous cell carcinoma. Enrichment analysis showed that G3BP1 was involved in the helicase/catalytic/ATPase activity functions and spliceosome/RNA transport/ cell cycle pathways. Furthermore, G3BP1 mRNA levels were positively associated with CD4⁺ T-cell infiltration.

CONCLUSIONS

G3BP1 may serve as a potential biomarker for proliferation, apoptosis, and prognosis of oral squamous cell carcinoma.

The multi-functional RNA-binding protein G3BP1 and its potential implication in neurodegenerative disease

Ras-GTPase-activating protein (GAP)-binding protein 1 (G3BP1) is a multi-functional protein that is best known for its role in the assembly and dynamics of stress granules. Recent studies have highlighted that G3BP1 also has other functions related to RNA metabolism. In the context of disease, G3BP1 has been therapeutically targeted in cancers because its over-expression is correlated with proliferation of cancerous cells and metastasis. However, evidence suggests that G3BP1 is essential for neuronal development and possibly neuronal maintenance. In this review, we will examine the many functions that are carried out by G3BP1 in the context of neurons and speculate how these functions are critical to the progression of neurodegenerative diseases. Additionally, we will highlight the similarities and differences between G3BP1 and the closely related protein G3BP2, which is frequently overlooked. Although G3BP1 and G3BP2 have both been deemed important for stress granule assembly, their roles may differ in other cellular pathways, some of which are specific to the CNS, and presents an opportunity for further exploration.

LncRNA SPOCD1-AS from ovarian cancer extracellular vesicles remodels mesothelial cells to promote peritoneal metastasis via interacting with G3BP1

Background

Metastasis is the key cause of death in ovarian cancer patients. To figure out the biological nature of cancer metastasis is essential for developing effective targeted therapy. Here we investigate how long non-coding RNA (lncRNA) SPOCD1-AS from ovarian cancer extracellular vesicles (EVs) remodel mesothelial cells through a mesothelial-to-mesenchymal transition (MMT) manner and facilitate peritoneal metastasis.

Methods

EVs purified from ovarian cancer cells and ascites of patients were applied to mesothelial cells. The MMT process of mesothelial cells was assessed by morphology observation, western blot analysis, migration assay and adhesion assay. Altered lncRNAs of EV-treated mesothelial cells were screened by RNA sequencing and identified by qRT-PCR. SPOCD1-AS was overexpressed or silenced by overexpression lentivirus or shRNA, respectively. RNA pull-down and RNA immunoprecipitation assays were conducted to reveal the mechanism by which SPOCD1-AS remodeled mesothelial cells. Interfering peptides were synthesized and applied. Ovarian cancer orthotopic implantation mouse model was established in vivo.

Results

We found that ovarian cancer-secreted EVs could be taken into recipient mesothelial cells, induce the MMT phenotype and enhance cancer cell adhesion to mesothelial cells. Furthermore, SPOCD1-AS embedded in ovarian cancer-secreted EVs was transmitted to mesothelial cells to induce the MMT process and facilitate peritoneal colonization in vitro and in vivo. SPOCD1-AS induced the MMT process of mesothelial cells via interacting with G3BP1 protein. Additionally, G3BP1 interfering peptide based on the F380/F382 residues was able to block SPOCD1-AS/G3BP1 interaction, inhibit the MMT phenotype of mesothelial cells, and diminish peritoneal metastasis in vivo.

Conclusions

Our findings elucidate the mechanism associated with EVs and their cargos in ovarian cancer peritoneal metastasis and may provide a potential approach for metastatic ovarian cancer therapeutics.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-01899-6.

Circ_0119872 promotes uveal melanoma development by regulating the miR-622/G3BP1 axis and downstream signalling pathways

Background

The abnormal expression of circular RNAs (circRNAs) in uveal melanoma (UM) has been revealed, but the specific underlying molecular mechanism of their association with UM development has not been fully explored.

Methods

The levels of circ_0119872, G3BP1 and miR-622 in UM cell lines and tissues were determined by quantitative real-time PCR (qRT-PCR) and western blotting assays. In vitro and in vivo assays were performed to investigate the function of circ_0119872 in the tumorigenesis of UM cells. The relationships among circ_0119872, miR-622 and G3BP1 were predicted using bioinformatic tools and verified by RNA-FISH, RNA pull-down and dual-luciferase reporter assays. The effects of circ_0119872 on Wnt/β-catenin and mTOR signalling pathways were determined by gene set enrichment analysis (GSEA) and western blotting.

Results

We found that circ_0119872 is upregulated in UM cell lines and tissues. Moreover, overexpression of circ_0119872 promotes the malignancy of UM cells, while silencing of circ_0119872 inhibits it. In addition, circ_0119872 can directly interact with miR-622 as a miRNA sponge that regulates the expression of the miR-622 target gene G3BP1 as well as downstream Wnt/β-catenin and mTOR signalling pathways.

Conclusions

Circ_0119872 may act as an oncogene in UM through a novel circ_0119872/miR-622/G3BP1 axis, activating the Wnt/β-catenin and mTOR signalling pathways, which in turn may provide potential biomarkers and therapeutic targets for the management of UM.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-01833-w.

Curcumol improves cisplatin sensitivity of human gastric cancer cells through inhibiting PI3K/AKT pathway

BACKGROUND

Curcumol was presented to unleash antitumor effects in a variety of cancers, including gastric cancer. However, the relevance between curcumol and cisplatin resistance in gastric cancer still remains unclear. Therefore, the current research was performed to survey the role of curcumol in cisplatin sensitivity in gastric cancer.

METHODS

First, BGC-823 and BGC-823/DDP cells were incubated with cisplatin for 48 hr and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) analysis was applied to determine the inhibition rate of cell proliferation and the half-maximal inhibitory concentration (IC50 ) of cisplatin. In addition, BGC-823 and BGC-823/DDP cells were treated with curcumol for 48 hr followed with detection of cell viability and apoptosis using MTT and flow cytometry assay, respectively. Moreover, MTT analysis was applied to test the effects of curcumol on cisplatin sensitivity in gastric cancer cells. Lastly, Western blot assay and qRT-PCR analysis were utilized to check the functions of curcumol on PI3K/AKT pathway-related markers.

RESULTS

We found that BGC-823/DDP cells exhibited stronger resistance to cisplatin compared with BGC-823 cells. Furthermore, curcumol evidently reduced cell proliferation and facilitated cell apoptosis in BGC-823/DDP and BGC-823 cells. Moreover, results from MTT assay demonstrated that curcumol notably promoted the suppression effect of cisplatin and decreased the IC50 of cisplatin in BGC-823/DDP and BGC-823 cells. It was also presented that curcumol suppressed the PI3K/AKT pathway dose-dependently in BGC-823/DDP and BGC-823 cells.

CONCLUSION

The findings in the current research demonstrated that curcumol could promote the sensitivity of gastric cancer cells to cisplatin-based chemotherapies via inhibiting the phosphatidylinositol 3-kinase (PI3K)/Protein Kinase B (AKT) pathway.

FadA promotes DNA damage and progression of Fusobacterium nucleatum-induced colorectal cancer through up-regulation of chk2

Background

Globally, colorectal cancer (CRC) affects more than 1 million people each year. In addition to non-modifiable and other environmental risk factors, Fusobacterium nucleatum infection has been linked to CRC recently. In this study, we explored mechanisms underlying the role of Fusobacterium nucleatum infection in the progression of CRC in a mouse model.

Methods

C57BL/6 J-Adenomatous polyposis coli (APC) Min/J mice [APC (Min/+)] were treated with Fusobacterium nucleatum (10⁹ cfu/mL, 0.2 mL/time/day, i.g., 12 weeks), saline, or FadA knockout (FadA−/−) Fusobacterium nucleatum. The number, size, and weight of CRC tumors were determined in isolated tumor masses. The human CRC cell lines HCT29 and HT116 were treated with lentiviral vectors overexpressing chk2 or silencing β-catenin. DNA damage was determined by Comet assay and γH2AX immunofluorescence assay and flow cytometry. The mRNA expression of chk2 was determined by RT-qPCR. Protein expression of FadA, E-cadherin, β-catenin, and chk2 were determined by Western blot analysis.

Results

Fusobacterium nucleatum treatment promoted DNA damage in CRC in APC (Min/+) mice. Fusobacterium nucleatum also increased the number of CRC cells that were in the S phase of the cell cycle. FadA−/− reduced tumor number, size, and burden in vivo. FadA−/− also reduced DNA damage, cell proliferation, expression of E-cadherin and chk2, and cells in the S phase. Chk2 overexpression elevated DNA damage and tumor growth in APC (Min/+) mice.

Conclusions

In conclusion, this study provided evidence that Fusobacterium nucleatum induced DNA damage and cell growth in CRC through FadA-dependent activation of the E-cadherin/β-catenin pathway, leading to up-regulation of chk2.

Aberrant NSUN2-mediated m5C modification of H19 lncRNA is associated with poor differentiation of hepatocellular carcinoma

RNA methylation is an important epigenetic modification. Recent studies on RNA methylation mainly focus on the m⁶A modification of mRNA, but very little is known about the m⁵C modification. NSUN2 is an RNA methyltransferase responsible for the m⁵C modification of multiple RNAs. In this study, we knocked down the NSUN2 gene in HepG2 cells by CRISPR/Cas9 technology and performed high-throughput RNA-BisSeq. An important tumor-related lncRNA H19 was identified to be targeted by NSUN2. Studies have shown that the expression of H19 lncRNA is abnormally elevated and has a carcinogenic effect in many types of tumors. Our results demonstrated that m⁵C modification of H19 lncRNA can increase its stability. Interestingly, m⁵C-modified H19 lncRNA can be specifically bound by G3BP1, a well-known oncoprotein which further leads to MYC accumulation. This may be a novel mechanism by which lncRNA H19 exerts its oncogenic effect. Besides, both the m⁵C methylation level and the expression level of H19 lncRNA in hepatocellular carcinoma tissues were significantly higher than those in adjacent non-cancer tissues, which were closely associated with poor differentiation of hepatocellular carcinoma (HCC). In conclusion, we found that H19 RNA is a specific target for the NSUN2 modifier. The m⁵C-modified H19 lncRNA may promote the occurrence and development of tumors by recruiting the G3BP1 oncoprotein. Our findings may provide a potential target and biomarker for the diagnosis and treatment of HCC.

Chromosomal Repositioning and Gene Regulation of Cells on a Micropillar Array

While various cell responses on material surfaces have been examined, relatively few reports are focused on significant self-deformation of cell nuclei and corresponding chromosomal repositioning. Herein, we prepared a micropillar array of poly(lactide-co-glycolide) (PLGA) and observed significant nuclear deformation of HeLa cells on the polymeric micropillars. In particular, we detected the territory positioning of chromosomes 18 and 19 and gene expression profiles of HeLa cells on the micropillar array using fluorescence in situ hybridization and a DNA microarray. Chromosome 18 was found to be translocated closer to the nuclear periphery than chromosome 19 on the micropillar array. With the repositioning of chromosomal territories, HeLa cells changed their gene expressions on the micropillar array with 180 genes upregulated and 255 genes downregulated for all of the 23 pairs of chromosomes under the experimental conditions and the employed Bioinformatics criteria. Hence, this work deepens the understanding on cell-material interactions by revealing that material surface topography can probably influence chromosomal repositioning in the nuclei and gene expressions of cells.

HiFreSP: A novel high-frequency sub-pathway mining approach to identify robust prognostic gene signatures

With the increasing awareness of heterogeneity in cancers, better prediction of cancer prognosis is much needed for more personalized treatment. Recently, extensive efforts have been made to explore the variations in gene expression for better prognosis. However, the prognostic gene signatures predicted by most existing methods have little robustness among different datasets of the same cancer. To improve the robustness of the gene signatures, we propose a novel high-frequency sub-pathways mining approach (HiFreSP), integrating a randomization strategy with gene interaction pathways. We identified a six-gene signature (CCND1, CSF3R, E2F2, JUP, RARA and TCF7) in esophageal squamous cell carcinoma (ESCC) by HiFreSP. This signature displayed a strong ability to predict the clinical outcome of ESCC patients in two independent datasets (log-rank test, P = 0.0045 and 0.0087). To further show the predictive performance of HiFreSP, we applied it to two other cancers: pancreatic adenocarcinoma and breast cancer. The identified signatures show high predictive power in all testing datasets of the two cancers. Furthermore, compared with the two popular prognosis signature predicting methods, the least absolute shrinkage and selection operator penalized Cox proportional hazards model and the random survival forest, HiFreSP showed better predictive accuracy and generalization across all testing datasets of the above three cancers. Lastly, we applied HiFreSP to 8137 patients involving 20 cancer types in the TCGA database and found high-frequency prognosis-associated pathways in many cancers. Taken together, HiFreSP shows higher prognostic capability and greater robustness, and the identified signatures provide clinical guidance for cancer prognosis. HiFreSP is freely available via GitHub: https://github.com/chunquanlipathway/HiFreSP.

Combination treatment with artemisinin and oxaliplatin inhibits tumorigenesis in esophageal cancer EC109 cell through Wnt/β-catenin signaling pathway

Background

Esophageal cancer (EC) is a prevalent malignant cancer worldwide. Interestingly, the antimalaria compound artemisinin (ART) is also reported to have anticancer potential, although its underlying mechanism in EC is unclear. In this study, we explored the anticancer role of ART in EC109 and further explored the combination of ART and oxaliplatin (OXA) for their synergetic anticancer functions.

Methods

Human EC cell line EC109 was used. After ART or oxaliplatin (OXA) treatment, cell proliferation, migration, and invasion were measured by MTT, transwell, and scratch wound assays, respectively. Flow cytometry was performed to examine the cell cycle and apoptosis. The mRNA and protein levels were determined using qRT‐PCR and western blotting.

Results

The migration and invasion abilities of EC109 were suppressed by ART. This was due to the inhibitory effect of ART on the Wnt/β‐catenin signaling pathway. The levels of β‐catenin, c‐myc, and survivin were also downregulated by ART. ART inhibits the proliferation of EC109 cells by arresting the cells in the G1‐phase of cell cycle. By using LiCl, an activator of the Wnt/β‐catenin pathway, we further verified that the inhibition of the Wnt/β‐catenin pathway was indeed due to ART. Remarkably, ART enhanced the anticancer effects of OXA in EC109 cells. OXA combined with ART was found to be more efficient in decreasing tumor growth compared to the individual drugs.

Conclusions

ART could suppress tumor progression by inhibiting Wnt/β‐catenin signaling pathway, and it may also enhance the antitumor effect of OXA in EC. Thus, ART could be a novel anticancer drug for EC treatment.

Key points

Significant findings of the study

ART could be a novel anticancer drug for esophageal cancer (EC) treatment.

What this study adds

Combination treatment with artemisinin and oxaliplatin inhibits tumorigenesis in esophageal cancer EC109 cells through the Wnt/β‐catenin signaling pathway.

METTL3 promotes the proliferation and invasion of esophageal cancer cells partly through AKT signaling pathway

Methyltransferase-like 3 (METTL3) is identified as a methyltransferase responsible for N⁶-methyladenosine (m⁶A) modification of mRNA, miRNA and lncRNA. Emerging evidences suggest that METTL3 is involved in tumorigenesis and progression of multiple tumor types. However, the functional role of METTL3 in esophageal cancer (EC) remains unclear. We used specific shRNA to down-regulate the METTL3 expression, and used pcDNA3.1-METTL3 cDNA plasmid to up-regulate the METTL3 expression in Eca-109 and KY-SE150 cells. Biological functions of METTL3 were performed by CCK-8, colony formation, apoptosis analysis, transwell and wound healing assays. Finally, an in-depth mechanism study was performed by an AKT inhibitor. METTL3 knockdown reduced the proliferation, clonality, migration and invasion of Eca-109 and KY-SE150 cells, and induced cell apoptosis, which may be mediated by activation of the mitochondrial apoptotic pathway. Further, METTL3 overexpression promoted the proliferation, clonality, migration and invasion of Eca-109 and KY-SE150 cells, and inhibited cell apoptosis. In addition, METTL3 regulated the expression of Wnt/β-catenin and AKT signaling pathway components. A double-effect inhibitor (BEZ235) inhibited AKT and mTOR phosphorylation and hindered the effect of METTL3 overexpression on the proliferation and migration of Eca-109 and KY-SE150 cells. Our data suggest that METTL3 plays a carcinogenic role in human EC progression partially through AKT signaling pathways, suggesting that METTL3 may serve as a potential therapeutic target for EC therapy.

Evodiamine Exerts Anticancer Effects Against 143B and MG63 Cells Through the Wnt/β-Catenin Signaling Pathway

Background

Osteosarcoma is the most common primary malignant bone neoplasm and is associated with abysmal prognosis. There are limitations of current treatment methods. Therefore, developing new agents to treat osteosarcoma is exceptionally urgent.

Aim

This study aimed to evaluate the anticancer effects of evodiamine (EVO) on osteosarcoma cells and, meanwhile, to investigate the underlying mechanisms involved.

Materials and Methods

The effect of EVO on the proliferation of osteosarcoma was detected by MTT assay, crystal violet assay and colony formation assay. The effects of EVO on the migration and invasion of osteosarcoma were detected by wound-healing assay and transwell assay. The effect of EVO on apoptosis of osteosarcoma was measured by Hoechst 33258 staining and cell cycle assay. The protein expression levels were detected by Western blotting assay. The activity of Wnt/β-Catenin signaling pathway was detected by luciferase reporter assay and Western blotting assay.

Results

According to MTT, crystal violet and colony formation assay results, EVO significantly inhibited the cell proliferation in a dose-dependent manner. Hoechst 33258 staining assay revealed that EVO induced cell apoptosis in a concentration-dependent manner. Moreover, EVO inhibited the migration and invasion of the osteosarcoma cells. Mechanistic studies revealed that EVO suppresses metastatic through suppressing epithelial–mesenchymal transition (EMT) as indicated by elevating the expression of epithelial marker E‐cadherin and reducing the expression of mesenchymal markers N‐cadherin and vimentin, as well as EMT transcription factors Snail and MMPs. Subsequently, EVO induced cell cycle arrest at the G2/M phase that correlated with reduced levels of cyclin D1 protein, while the apoptotic effects of EVO were associated with the upregulation of Bax and Bad and a decrease in Bcl-2 protein levels. Furthermore, EVO exerted the anticancer effects by suppressing Wnt/β-catenin signal pathway in osteosarcoma cells.

Conclusion

In summary, EVO exhibited potent anticancer effects against human osteosarcoma cells and promoted apoptosis through suppressing Wnt/β-catenin signaling pathway. These results indicated that EVO may be regarded as a new approach for osteosarcoma treatment.

ADAM10 promotes cell growth, migration, and invasion in osteosarcoma via regulating E-cadherin/β-catenin signaling pathway and is regulated by miR-122-5p

Background

Osteosarcoma is a malignant bone tumor. Increasing evidences have revealed that a disintegrin and metalloproteinase 10 (ADAM10) is implicated in tumor development. The main purpose of this study is to explore the effects of ADAM10 on osteosarcoma cell functions and the underlying molecular mechanisms.

Methods

Western blot and quantitative real-time PCR were performed to detect the expression of ADAM10 in one osteoblast (hFOB 1.19) and six osteosarcoma cells (Saos-2, SW1353, HOS, U-2OS, MG63, and 143B). The biological functions of ADAM10 in osteosarcoma cells were measured by cell counting kit-8 assay, flow cytometry, wound healing assay, and transwell assay. The interaction between miR-122-5p and ADAM10 was validated using dual-luciferase reporter assay. The effect of ADAM10 on the tumorigenicity of osteosarcoma cells was evaluated in a nude mice model in vivo.

Results

We found that the expression of ADAM10 was relatively high in osteosarcoma cells compared with that in osteoblast. ADAM10 promoted osteosarcoma cell growth, migration, and invasion. Mechanism studies showed that knockdown of ADAM10 inactivated E-cadherin/β-catenin signaling pathway, as evidenced by increased the level of E-cadherin, reduced nuclear translocation of β-catenin, and decreased the levels of MMP-9, Cyclin D1, c-Myc, and Survivin. Downregulation of ADAM10 suppressed the tumorigenicity of osteosarcoma cells in vivo. Furthermore, ADAM10 was validated to be a downstream target of microRNA-122-5p (miR-122-5p). MiR-122-5p-induced inhibition of cell proliferation, migration, and invasion was reversed by overexpression of ADAM10 in osteosarcoma cells.

Conclusions

Collectively, the key findings of this study are that ADAM10 promotes osteosarcoma cell proliferation, migration, and invasion by regulating E-cadherin/β-catenin signaling pathway, and miR-122-5p can target ADAM10, indicating that miR-122-5p/ADAM10 axis might serve as a therapeutic target of osteosarcoma.

The Role Played by Wnt/β-Catenin Signaling Pathway in Acute Lymphoblastic Leukemia

Acute lymphoblastic leukemia (ALL) is an aggressive hematologic neoplastic disorder that arises from the clonal expansion of transformed T-cell or B-cell precursors. Thanks to progress in chemotherapy protocols, ALL outcome has significantly improved. However, drug-resistance remains an unresolved issue in the treatment of ALL and toxic effects limit dose escalation of current chemotherapeutics. Therefore, the identification of novel targeted therapies to support conventional chemotherapy is required. The Wnt/β-catenin pathway is a conserved signaling axis involved in several physiological processes such as development, differentiation, and adult tissue homeostasis. As a result, deregulation of this cascade is closely related to initiation and progression of various types of cancers, including hematological malignancies. In particular, deregulation of this signaling network is involved in the transformation of healthy HSCs in leukemic stem cells (LSCs), as well as cancer cell multi-drug-resistance. This review highlights the recent findings on the role of Wnt/β-catenin in hematopoietic malignancies and provides information on the current status of Wnt/β-catenin inhibitors with respect to their therapeutic potential in the treatment of ALL.

Targeting Wnt/β-catenin and PI3K/Akt/mTOR pathways in T-cell acute lymphoblastic leukemia

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematological disorder that results from the clonal transformation of T-cell precursors. Phosphatidylinositol 3-kinase (PI3K)/Akt/mechanistic target of rapamycin (mTOR) and canonical Wnt/β-catenin signaling pathways play a crucial role in T-cell development and in self-renewal of healthy and leukemic stem cells. Notably, β-catenin is a transcriptional regulator of several genes involved in cancer cell proliferation and survival. In this way, aberrations of components belonging to the aforementioned networks contribute to T-ALL pathogenesis. For this reason, inhibition of both pathways could represent an innovative strategy in this hematological malignancy. Here, we show that combined targeting of Wnt/β-catenin pathway through ICG-001, a CBP/β-catenin transcription inhibitor, and of the PI3K/Akt/mTOR axis through ZSTK-474, a PI3K inhibitor, downregulated proliferation, survival, and clonogenic activity of T-ALL cells. ICG-001 and ZSTK-474 displayed cytotoxic effects, and, when combined together, induced a significant increase in apoptotic cells. This induction of apoptosis was associated with the downregulation of Wnt/β-catenin and PI3K/Akt/mTOR pathways. All these findings were confirmed under hypoxic conditions that mimic the bone marrow niche where leukemic stem cells are believed to reside. Taken together, our findings highlight potentially promising treatment consisting of cotargeting Wnt/β-catenin and PI3K/Akt/mTOR pathways in T-ALL settings.

Elevated expression of G3BP1 associates with YB1 and p-AKT and predicts poor prognosis in nonsmall cell lung cancer patients after surgical resection

Purpose

G3BP1 is an RNA‐binding protein and plays roles in regulating signaling pathway. YB‐1 is a DNA/RNA binding protein encoded by YBX1 gene. Phosphorylated AKT (p‐AKT) acts as a pivotal molecule in PI3K/AKT pathway. YB‐1 drives stress granules (SGs) formation by activating G3BP1 translation under diverse conditions. SGs are involved in many different metabolic and signaling pathways which may include PI3K/AKT/mTOR. So far, there has been no report on the relationship between expression of G3BP1, p‐AKT, and YB1 and clinicopathological features/prognosis in surgically resected nonsmall cell lung cancer (NSCLC) patients.

Methods

In this study, data from TCGA (The Cancer Genome Atlas) were downloaded to investigate the mRNA expression of G3BP1 and YB1 (YBX1) and their correlation in NSCLC. Also, expression of G3BP1, YB1, and p‐AKT proteins was studied using immunohistochemistry in tissue microarrays of NSCLC and in noncancerous lung tissues.

Results

We found that the mRNA expression of G3BP1 and YB1 was higher in NSCLC tissues (both P < .05), and G3BP1 was positively correlated with YB1 in mRNA level (r = .399, P < .001). Also, expression of G3BP1, YB1, and p‐AKT proteins was higher in NSCLC tissues (all P < .05). And higher expression of G3BP1 and YB1 proteins was seen in patients with clinical stage II and III compared with stage I (both P < .05). Besides, expression of G3BP1 protein had a positive correlation with YB1 and p‐AKT (both P < .05). Moreover, overall survival was shorter in patients with overexpression of G3BP1, YB1, and p‐AKT proteins (all P < .05). Multivariate analysis confirmed that overexpression of G3BP1 protein was an independent poorer prognostic factor for NSCLC patients (P = .039).

Conclusion

G3BP1 may play a crucial role in activating PI3K/AKT/mTOR pathway. G3BP1 might be served as a novel prognostic biomarker for surgically resected NSCLC patients, which afforded new insights into the study on the mechanism and therapy of NSCLC.